<p>Two days ago I released the first major version in almost 2 years for <a target="_blank" rel="noopener noreferrer" href="https://github.com/shlinkio/shlink-web-client">shlink-web-client</a>, a web UI for <a target="_blank" rel="noopener noreferrer" href="https://shlink.io">shlink</a>, my self-hosted URL shortener.</p><p>This new version introduces several improvements to the project, and I thought it was worth writing a post to explain all of them in depth.</p><h3>New design</h3><p>The project has been using the same design almost since the beginning. It was clean, but it laked a bit of contrast and consistency in many sections.</p><p>Now the main background is light-gray, with components composed in white cards with a slight box shadow, that makes them easier to spot inside the app.</p><p>Also, the main area has now a max-width that prevents components from stretching too much on wide screens.</p><div class="row"><div class="col-md-6  "><img alt="Before" src="/assets/img/shlink-web-client-3/design-before.png" class="gallery-item"/><p class="text-center"><small>Before</small></p></div><div class="col-md-6  "><img alt="After" src="/assets/img/shlink-web-client-3/design-after.png" class="gallery-item"/><p class="text-center"><small>After</small></p></div></div><h3>Overview page</h3><p>Up until now, after connecting to a Shlink server, you went directly to the list of short URLs.</p><p>With this new version, you now see an overview page first, which displays some general stats, a quick short URL creation form, and the latest 5 short URLs.</p><p>From there, you can navigate to the full list of short URLs, with filtering capabilities, or go to the advanced short URL creation form.</p><div class="row"><div class="col-md-8 col-md-offset-2 "><img alt="Overview" src="/assets/img/shlink-web-client-3/overview.png" class="gallery-item"/><p class="text-center"><small>Overview</small></p></div></div><h3>Improved short URL creation form</h3><p>One of the sections with more room for improvement was the short URL creation form. It had all the inputs mixed, displaying just the &quot;long url&quot; one, with the option to un-collapsing the rest at will.</p><p>The new design groups the inputs by context, which makes it more clear. It also displays the inputs all the time, since the &quot;quick form&quot; is now located in the overview page.</p><div class="row"><div class="col-md-6  "><img alt="Before" src="/assets/img/shlink-web-client-3/creation-form-before.png" class="gallery-item"/><p class="text-center"><small>Before</small></p></div><div class="col-md-6  "><img alt="After" src="/assets/img/shlink-web-client-3/creation-form-after.png" class="gallery-item"/><p class="text-center"><small>After</small></p></div></div><h3>Enhanced visits page</h3><p>The visits page had a problem, it was trying to display too much information in a single place.</p><ul><li>Visits over time</li><li>Visits from every platform</li><li>Visits from every location</li><li>A list of visits as a table</li></ul><p>The new approach splits those in subsections with their own sub-route each (<code>/by-location</code>, <code>/by-context</code>, etc). This helps to render a smaller amount of charts at once, since they are a bit CPU greedy.</p><p>Also, only the visits from the last 30 days are loaded by default, making it load way faster for URLs with a lot of visits.</p><div class="row"><div class="col-md-6  "><img alt="Before" src="/assets/img/shlink-web-client-3/visits-before.png" class="gallery-item"/><p class="text-center"><small>Before</small></p></div><div class="col-md-6  "><img alt="After" src="/assets/img/shlink-web-client-3/visits-after.png" class="gallery-item"/><p class="text-center"><small>After</small></p></div></div><h3>Outer sections</h3><p>The app has some sections which are not related to a specific server, like creating/editing servers, or the settings page.</p><p>These sections have also been adapted to the new style, and they also have a max-width for wide screens.</p><div class="row"><div class="col-md-6  "><img alt="Before" src="/assets/img/shlink-web-client-3/create-server-before.png" class="gallery-item"/><p class="text-center"><small>Before</small></p></div><div class="col-md-6  "><img alt="After" src="/assets/img/shlink-web-client-3/create-server-after.png" class="gallery-item"/><p class="text-center"><small>After</small></p></div></div><h3>Date range selector</h3><p>A new component allows selecting date ranges either by relative time ranges (last 30 days, last 90 days...) or by selecting absolute start and end dates.</p><p>This component is used to filter both short URL lists and visits lists.</p><div class="row"><div class="col-md-6  col-md-offset-3"><img alt="Date range selector" src="/assets/img/shlink-web-client-3/date-range-selector.png" class=""/><p class="text-center"><small>Date range selector</small></p></div></div><h3>Domain selector</h3><p>Shlink has had multi-domain support for some versions, but changing the domain from the web client required to set the value manually, which is a bit error-prone.</p><p>This version introduces a new component which allows selecting from domains already used in the past (which is what you will want in most of the cases), preventing accidental typos.</p><p>It also allows setting new values in case you want to use a new domain that you never used before. This domain will then appear in the list the next time.</p><div class="row"><div class="col-md-6  "><img alt="Existing domains" src="/assets/img/shlink-web-client-3/domains-existing.png" class=""/><p class="text-center"><small>Existing domains</small></p></div><div class="col-md-6  "><img alt="New domain" src="/assets/img/shlink-web-client-3/domains-new.png" class=""/><p class="text-center"><small>New domain</small></p></div></div><h3>Other improvements</h3><p>The changes described so far were the major ones. However, v3.0.0 includes a few other minor improvements.</p><ul><li>Result and loading messages have been standardized: They are now more consistent and use the same set of components, which also ensures consistency in the future.</li><li>Error messages are now more descriptive: Instead of showing generic error messages when API calls fail, the actual error message is now always displayed, so that it&#x27;s easier to know what failed.</li><li>Dropped support for Shlink v1: All major versions come with some breaking changes that improve code maintainability. This one drops Shlink v1 support, which allows removing some conditional paths here and there.</li></ul><p>Other than the last point, Shlink v3.0.0 is mostly backwards compatible, so it&#x27;s safe to upgrade if you are already using Shlink v2.x</p><h3>Next steps</h3><p>Of course this doesn&#x27;t end here, and I have a lot of ideas to improve it even further.</p><ul><li>Dark theme: It&#x27;s what the cool kids do these days, and I have already done some experiments around it.</li><li>Shlink dashboard: Next gen web app for Shlink. You can read the whole reasoning in <a target="_blank" rel="noopener noreferrer" href="https://github.com/shlinkio/shlink-web-client/issues/338">this issue</a>.</li><li>Filtering in lists added to URL: Many sections allow filtering lists, but the state is saved in memory, which means it gets lost if the page is refreshed, and it cannot be bookmarked. The intention is to make all filtering params to become part of the URL.</li><li>Exporting visits in CSV: It&#x27;s cool to see charts full of info, but sometimes admins need to feed other services with the data, and consuming the original API is not always an option. Exporting visits to a CSV file will be supported soon by shlink-web-client.</li></ul>

Released shlink-web-client v3.0.0

<p>Let&#x27;s not deny that <a target="_blank" rel="noopener noreferrer" href="https://github.com/features/actions">GitHub actions</a> are hitting hard in the tech community, and many projects are transitioning from other continuous integration systems like <a target="_blank" rel="noopener noreferrer" href="https://circleci.com/">Circle CI</a> or <a target="_blank" rel="noopener noreferrer" href="https://travis-ci.org/">Travis CI</a>.</p><p>Personally I have been using Travis a lot during the past years, for all my OSS projects, and I have gotten very used to it.</p><p>However, people seem to be &quot;abandoning&quot; travis in favor of GitHub Actions, for different reasons. &quot;It&#x27;s faster&quot;, &quot;I can run smaller tasks in parallel&quot;, etc.</p><p>In my case, I have moved a few very specific tasks there, where travis was becoming a bottleneck, but I still have mixed feelings about the very-verbose yaml-based config needed to configure a few GitHub Actions, compared to the more concise travis one.</p><p>In this article I&#x27;ll explain how I improved a travis build to run several smaller tasks in parallel jobs, without having to completely move away from it.</p><h3>Initial state</h3><p>This project&#x27;s travis config is relatively simple. It is used to build a JS project for the web browser, and it has to run the next tasks:</p><ul><li>Lint the code, to make sure it fulfils the project&#x27;s coding standards.</li><li>Run unit tests.</li><li>Run mutation tests.</li><li>Build the docker image, to make sure none of the new changes broke it.</li><li>Conditionally publish a release on GitHub, with a dist file attached to it, if the build is being run for a git tag.</li></ul><pre><pre><code class="language-yaml">dist: bionic

language: node_js

branches:
  only:
    - /.*/

cache:
  directories:
    - node_modules

services:
  - docker

node_js:
  - &#x27;12.16.3&#x27;

install: npm ci

before_script:
  - echo &quot;Building commit range ${TRAVIS_COMMIT_RANGE}&quot;
  - export MUTATION_FILES=$(git diff ${TRAVIS_COMMIT_RANGE:-origin/main} --name-only | grep -E &#x27;src\/(.*).(ts|tsx)$&#x27; | paste -sd &quot;,&quot;)

script:
  - npm run lint
  - npm run test:ci
  - npm run mutate:ci
  - docker build -t project:test .

after_success:
  - node_modules/.bin/ocular coverage/clover.xml

before_deploy: npm run build ${TRAVIS_TAG#?}

deploy:
  - provider: releases
    api_key:
      secure: &lt;key&gt;
    file: &quot;./dist/project_${TRAVIS_TAG#?}_dist.zip&quot;
    skip_cleanup: true
    on:
      tags: true
</code></pre></pre><h3>Problems with this approach</h3><p>This is more or less ok, but the last two commands in <code>script</code> can be relatively slow and can delay the whole process.</p><p>Also, specially the mutation tests one, which is currently always considered successful regardless the result, can make the build reach the maximum run time allowed by travis, making the whole build falsely fail.</p><blockquote><p>The reason for the <code>before_script</code> step is to determine which source code files changed, and run mutation tests on them only, in order to mitigate this.</p></blockquote><p>Other than this, the build config defines &quot;global&quot; customizations that are actually only used for some tasks:</p><ul><li>Running <code>npm ci</code> is not required for the <code>docker build</code> task.</li><li>Getting the <code>docker</code> service is not required by any of the other tasks.</li><li>Determining changed files is only used by the <code>mutation tests</code> task.</li></ul><h3>Making use of jobs</h3><p>One cool feature travis supports is the use of a job <a target="_blank" rel="noopener noreferrer" href="https://docs.travis-ci.com/user/build-matrix/">build matrix</a>, that lets you define multiple jobs that run in parallel as part of the same build, and make each one of them do unrelated tasks.</p><p>Using this feature it is possible to improve the <code>.travis.yml</code> file, making it look like this:</p><pre><pre><code class="language-yaml">dist: bionic

language: node_js

branches:
  only:
    - /.*/

cache:
  directories:
    - node_modules

node_js:
  - &#x27;12.16.3&#x27;

jobs:
  fast_finish: true
  allow_failures:
    - name: &#x27;Mutation tests&#x27;
  include:

    - name: &#x27;Lint&#x27;
      install: npm ci
      script: npm run lint

    - name: &#x27;Unit tests&#x27;
      install: npm ci
      script: npm run test:ci
      after_success:
        - node_modules/.bin/ocular coverage/clover.xml

    - name: &#x27;Mutation tests&#x27;
      install: npm ci
      before_script:
        - echo &quot;Building commit range ${TRAVIS_COMMIT_RANGE}&quot;
        - export MUTATION_FILES=$(git diff ${TRAVIS_COMMIT_RANGE:-origin/main} --name-only | grep -E &#x27;src\/(.*).(ts|tsx)$&#x27; | paste -sd &quot;,&quot;)
      script: npm run mutate:ci

    - name: &#x27;Build docker image&#x27;
      services:
        - docker
      install: skip
      script: docker build -t project:test .

    - name: &#x27;Publish release&#x27;
      if: tag IS present
      install: skip
      script: skip
      before_deploy: npm run build ${TRAVIS_TAG#?}
      deploy:
        - provider: releases
          api_key:
            secure: &lt;key&gt;
          file: &quot;./dist/project_${TRAVIS_TAG#?}_dist.zip&quot;
          skip_cleanup: true
          on:
            tags: true
</code></pre></pre><p>This approach introduces all these benefits:</p><ul><li>Now linting, testing, mutation testing and building the docker image run in parallel, making the build finish earlier.</li><li>The mutation testing step is allowed to fail, and thanks to the <code>fast_finish</code> flag, travis won&#x27;t even wait for it to finish, considering the build successful once the rest have passed.</li><li>Configs that are only meaningful for certain jobs are defined in the job itself, instead of globally.</li><li>The &quot;publish release&quot; job only runs conditionally if the build is for a tag, thanks to the <code>if: tag IS present</code> condition. (More info about <a target="_blank" rel="noopener noreferrer" href="https://docs.travis-ci.com/user/conditional-builds-stages-jobs/">conditional jobs</a> in travis).</li><li>As soon as any of the jobs fails, the whole build fails and you don&#x27;t have to continue waiting. Before this, if the third task failed, you still had to wait for the previous two to finish.</li><li>Each job can have a name, making it more clear in travis UI what tasks are being run:</li></ul><p><img src="/assets/img/travis-multiple-jobs/travis-jobs.png" alt="Travis CI jobs"/></p><h3>Conclusion</h3><p>The main purpose of this article was to showcase that travis still has a lot to give. Github Actions are definitely cool, but there&#x27;s usually no silver bullet for everything, and a combination with other tools might be more suitable.</p><p>Also, this allows people using travis to improve their builds without having to change everything. Then, once you have split your tasks, if you still want to move to Github Actions, it should be easier.</p><blockquote><p>If you are curious, this is the project in which I use this travis configuration: <a target="_blank" rel="noopener noreferrer" href="https://github.com/shlinkio/shlink-web-client">shlinkio/shlink-web-client</a>.</p></blockquote>

Running several steps of a Travis CI build in parallel

<p>Asynchronous and non-blocking runtimes are pretty usual in many programming languages, as well as long-lived web apps that stay in memory and are capable of dispatching multiple HTTP requests without having to be fully bootstrapped every time. This has not been traditionally the case with PHP apps. </p><p>However, many projects are starting to get some adoption, that bring this long-lived approach to the PHP world.</p><p>The problem with this is that PHP developers are not used to this, and they tend to continue acting as they have always done. Also, libraries might have made some assumptions, making them not work as expected when used under this context.</p><p>Some of these projects are <a target="_blank" rel="noopener noreferrer" href="https://www.swoole.co.uk">swoole</a>, <a target="_blank" rel="noopener noreferrer" href="https://reactphp.org/">ReactPHP</a> or <a target="_blank" rel="noopener noreferrer" href="https://amphp.org/">Amphp</a>, to give some examples.</p><p>In this article, I will be focusing on the first one, and explain how to approach some of the pain points I have found after using it for a year and a half on an <a target="_blank" rel="noopener noreferrer" href="https://github.com/shlinkio/shlink">existing PHP project</a>.</p><h3>Introducing Swoole</h3><p>The main difference swoole has compared to other similar projects is that it&#x27;s written as a native PHP extension, and needs to be installed with <code>pecl</code>.</p><p>This is obviously a bit cumbersome, but the benefit is that, since it&#x27;s written in C++, it has a better handling of memory allocation, which is very important to achieve what it tries to do.</p><p>What swoole does is running a main process which bootstraps the PHP application once, and then keeps it in memory so that it can continue dispatching requests without having to load resources every time. This makes it really fast.</p><p>Those HTTP requests are handled by a set of child processes called &quot;web workers&quot;. Swoole forks the contents in memory for the main process to each one of the workers, so each worker has a &quot;copy&quot; of the application in memory.</p><p>Each worker is independent, but each one of them can only handle one request at a time, so you have to increase the number of workers if you expect a lot of concurrent traffic.</p><p>Other than web workers, swoole also has another set of child processes called &quot;task workers&quot;, which can be used to delegate long tasks at runtime to prevent web workers from getting blocked.</p><p>Here you can see a diagram of swoole&#x27;s architecture.</p><p><img src="https://www.swoole.co.uk/images/how-swoole-works.png" alt="How Swoole works"/></p><blockquote><p>More information can be found in <a target="_blank" rel="noopener noreferrer" href="https://www.swoole.co.uk/how-it-works">Swoole&#x27;s website</a>.</p></blockquote><h3>Problems to solve</h3><p>Now that we know how swoole works, let&#x27;s see some of the challanges I have faced in th past, which are usually not that ovbious when you are used to think in terms of &quot;blocking&quot; and &quot;short-lived&quot;.</p><h4>Database connections are kept open</h4><p>One of the first things you find out is that, since the application stays in memory, any database connection that has been opened by a worker (either web or task worker), will be kept open and reused in subsequent executions or HTTP requests served by the app.</p><p>This, which is in theory good, has a side effect, which is not obvious during development: <strong>the opened connection will eventually expire</strong>.</p><p>Since most of the popular database abstraction layers in PHP are coming from the times in which PHP was just a bootstrap-on-every-request technology, they never cared too much about expired database connections, as they would be opened again on next request.</p><p>However, when using swoole and the like, you have to implement some mechanism which takes care of reconnecting or gracefully recovering when this happens.</p><blockquote><p>I wrote an article explaining how I solved this on a middleware-based app served with swoole and using doctrine: <a href="/2019/11/04/how-to-properly-handle-a-doctrine-entity-manager-on-an-expressive-application-served-with-swoole/">How to properly handle a doctrine entity manager on an expressive application served with swoole</a></p></blockquote><p>Obviously, swoole (and also others) provides some tools to work with databases (like this <a target="_blank" rel="noopener noreferrer" href="https://www.swoole.co.uk/docs/modules/swoole-async-mysql-client">MySQL client</a>), which I&#x27;m sure do not have this problem (although, I haven&#x27;t personally tried this), but they are more limited than other well adopted libraries.</p><h4>In-memory caches don&#x27;t behave as expected</h4><p>It is a frequent practice to use local in-memory caches, like APCu, to improve applications performance in production.</p><p>Usually APCu is faster than other options, like redis or memcached, so it&#x27;s the choice when you only have one instance of your app running (meaning, you don&#x27;t have a cluster behind a load balancer).</p><p>However, even if you are running your app on just one server with swoole, because of the web worker system explained earlier, you actually have several copies of your app in memory, and each one of them will have a separated and not shared cache when using APCu.</p><p>This can lead to inconsistencies which are hard to debug, so you need to have it in mind.</p><p>Also, since the information that is being loaded is kept in memory anyway, you will not notice such a big improvement by using APCu or other in-memory caches.</p><blockquote><p>Notice that this problem does not happen when using distributed/centralized caching solutions, such as redis or memcached, as in that case, the caching technology is shared by all workers.</p></blockquote><h4>No need to optimize file including/requiring</h4><p>Many projects have complex configuration systems which are spread into several files. While this make it more maintainable, it also has a performance impact when all those files need to be loaded on every request.</p><p>Because of that, there are libraries like <a target="_blank" rel="noopener noreferrer" href="https://github.com/laminas/laminas-config-aggregator">laminas-config-aggregator</a> that can dynamically load config from many sources and, if some conditions are met, they can merge the result in a single bigger file that can be used in later requests.</p><p>In the case of swoole, as all the files will be kept in memory once loaded for the first time, there&#x27;s no need for this kind of optimization.</p><h4>Class autoloading happens once</h4><p>This point is very related with the previous one.</p><p>Composer offers a lot of optimization options so that class autoloading is faster in production. While you usually will still want to use some of those so that the first time a class is being loaded it is still reasonably fast, any subsequent hits will just use the class which is already in memory.</p><p>One of the composer flags you will probably don&#x27;t want use with swoole is <code>--apcu-autoloader</code>, because of the reasons mentioned two points above this one.</p><h4>Services should be truly stateless</h4><p>This is something that you should always do anyway, but it&#x27;s specially important when a service instance is kept in memory between HTTP requests.</p><p>Sometimes it&#x27;s easy to end up having some small piece of internal state on a service, where we save something as a side effect of a method call, to end up using it when another one of the public methods is invoked.</p><p>While this could seem harmless when the whole app is bootstrapped on every request, it can have very dangerous side effects when the app is served with swoole, because the instance will persist until another request is dispatched by the same web worker.</p><p>Just imagine you saved some user data on a service, and it ends up being served to another user on the next request. That won&#x27;t look good.</p><p>Because of this, make sure your services are truly stateless, and if for any reason that&#x27;s not possible, at least remember to have some mechanism in place that flushes the data just before finishing the request.</p><h4>Hot reloading for dev envs is not that good</h4><p>One thing we usually take for granted is that we can modify a PHP file and just by making a new request, the new code will be executed. However, when the code is kept in memory, it&#x27;s not that straightforward.</p><p>When you are developing a project which is served with swoole, you will have to restart the server every time to get your changes applied.</p><p>Swoole has a mechanism to do a light server reload, which is faster. You can find the docs in <a target="_blank" rel="noopener noreferrer" href="https://www.swoole.co.uk/docs/modules/swoole-server-reload">it&#x27;s website</a>.</p><p>The problem with this is that you need to implement the mechanism to invoke that when a file is changed, or use some library that does it for you.</p><p>Also, I have noticed that even calling that and seeing that the server is reloaded, does not always have the expected effect, and you have to still end up doing a hard reload. It&#x27;s something I don&#x27;t fully understand and I still need to investigate a bit further.</p><h3>Conclusion</h3><p>As it always happens when new technologies appear, it takes some time to get used to them, but I strongly suggest you to give a try to swoole or any other non-blocking runtime, because it makes your apps super fast.</p><p>Just remember to have all of the above in mind ;-)</p><p>That said, here you can find some libraries that will make your life easier when trying to serve existing projects with swoole, without having to couple with it and being able to continue using your favourite framework:</p><ul><li>IDE helper: <a target="_blank" rel="noopener noreferrer" href="https://github.com/swoft-cloud/swoole-ide-helper">https://github.com/swoft-cloud/swoole-ide-helper</a></li><li>Mezzio (formerly Zend Expressive): <a target="_blank" rel="noopener noreferrer" href="https://github.com/mezzio/mezzio-swoole">https://github.com/mezzio/mezzio-swoole</a></li><li>Symfony: <a target="_blank" rel="noopener noreferrer" href="https://github.com/k911/swoole-bundle">https://github.com/k911/swoole-bundle</a></li><li>Laravel: <a target="_blank" rel="noopener noreferrer" href="https://github.com/swooletw/laravel-swoole">https://github.com/swooletw/laravel-swoole</a></li></ul><p>Also, here you can find some more articles talking about this topic:</p><ul><li><a target="_blank" rel="noopener noreferrer" href="https://www.zend.com/blog/why-you-should-use-asynchronous-php">https://www.zend.com/blog/why-you-should-use-asynchronous-php</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://samsonasik.wordpress.com/2020/04/05/using-swoole-in-mezzio-application-with-sdebug/">https://samsonasik.wordpress.com/2020/04/05/using-swoole-in-mezzio-application-with-sdebug/</a></li></ul>

Considerations when working with async PHP runtimes like swoole

<p>Some of you probably know that I have a pet project in which I like to work from time to time. This project is a self-hosted URL shortener called <a target="_blank" rel="noopener noreferrer" href="https://shlink.io">Shlink</a>.</p><p>Shlink is built using expressive as the base framework for the HTTP-dispatching task. A while ago, an expressive module was released to officially support serving expressive apps with <a target="_blank" rel="noopener noreferrer" href="https://www.swoole.co.uk/">swoole</a>, and I decided to include it on Shlink.</p><h3>How does swoole work?</h3><p>Swoole is an asynchronous non-blocking I/O framework which works in a similar way as node.js, but for PHP apps.</p><p>It has been conceived in a way that the app stays in memory between requests, removing the bootstrapping step and making apps to be served much faster.</p><p>Swoole can serve as many simultaneous requests as you tell it to. For this it makes use of workers. Each worker can serve one request at a time, and every worker has a separate instance of the app loaded in memory (this is something I <a target="_blank" rel="noopener noreferrer" href="https://twitter.com/dominikzogg/status/1189403552399134720">learned recently</a>).</p><p>Because of this, you have to sometimes change a bit the way you design your code. For example, if a service needs to be stateful (it shouldn&#x27;t, but shit happens), you will have to remember that the state will persist between requests, and you will want to somehow reset it to avoid unexpected side effects.</p><h3>How does this affect the EntityManager?</h3><p>One of the main services that keeps this internal state in Shlink is the doctrine <a target="_blank" rel="noopener noreferrer" href="https://www.doctrine-project.org/projects/doctrine-orm/en/current/tutorials/getting-started.html#obtaining-the-entitymanager">EntityManager</a>.</p><p>Due to the fact that it was originally designed to be used on a classical web server + CGI context, assuming it would be recreated on every request, there are a few considerations to take into account:</p><ul><li>It implements the unit of work pattern. It internally keeps track of all the entities that have been created/changed until you decide to flush it.</li><li>If something fails, the <code>EntityManager</code> can get closed, which makes it unusable after that moment.</li><li>If the database connection expires, the <code>EntityManager</code> will not gracefully recover. Instead, it will fail, since it&#x27;s not aware of the connection not being usable, getting yourself in previous point.</li></ul><h3>How to workaround it</h3><p>I learned about these issues by try and error, by using it on the app and getting the failures. Now, I want to share how I workaround those issues.</p><p>The first one I faced was the one making the app unusable after the <code>EntityManager</code> was closed. In order to solve this I created a decorated instance (naming, an object implementing <code>EntityManagerInterface</code> which in turn was wrapping an actual <code>EntityManager</code>), which was making sure the wrapped instance was transparently recreated if at some point it was closed.</p><p>However, this caused some side effects, and I finally realized that it was better to make the <code>EntityManager</code> to have to be reopened from the outside, and only once per request (this is closer to how it would behave on a classical set-up).</p><p>That&#x27;s how I came up with the <code>ReopeningEntityManager</code> Shlink is currently using (as of v1.20.0):</p><pre><pre><code class="language-php">&lt;?php

declare(strict_types=1);

namespace Shlinkio\Shlink\Common\Doctrine;

use Doctrine\ORM\Decorator\EntityManagerDecorator;

class ReopeningEntityManager extends EntityManagerDecorator
{
    /** @var callable */
    private $createEm;

    public function __construct(callable $createEm)
    {
        parent::__construct($createEm());
        $this-&gt;createEm = $createEm;
    }

    public function open(): void
    {
        if (! $this-&gt;wrapped-&gt;isOpen()) {
            $this-&gt;wrapped = ($this-&gt;createEm)();
        }
    }
}
</code></pre></pre><blockquote><p>You can find the actual code in <a target="_blank" rel="noopener noreferrer" href="https://github.com/shlinkio/shlink-common/blob/master/src/Doctrine/ReopeningEntityManager.php">shlink-common</a>.</p></blockquote><p>It just expects a factory that creates the actual <code>EntityManager</code>, and exposes an <code>open</code> public method which re-creates the wrapped instance if closed.</p><p>This method is called from a <a target="_blank" rel="noopener noreferrer" href="https://www.php-fig.org/psr/psr-15/">PSR-15</a> middleware which needs to be registered early in the middleware pipeline. It makes sure the method is called before the next middleware on the stack is invoked:</p><pre><pre><code class="language-php">&lt;?php

declare(strict_types=1);

namespace Shlinkio\Shlink\Common\Middleware;

use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\MiddlewareInterface;
use Psr\Http\Server\RequestHandlerInterface;
use Shlinkio\Shlink\Common\Doctrine\ReopeningEntityManager;

class CloseDbConnectionMiddleware implements MiddlewareInterface
{
    /** @var ReopeningEntityManager */
    private $em;

    public function __construct(ReopeningEntityManager $em)
    {
        $this-&gt;em = $em;
    }

    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
    {
        $this-&gt;em-&gt;open();

        try {
            return $handler-&gt;handle($request);
        } finally {
            $this-&gt;em-&gt;getConnection()-&gt;close();
            $this-&gt;em-&gt;clear();
        }
    }
}
</code></pre></pre><blockquote><p>Again, the code can be found in <a target="_blank" rel="noopener noreferrer" href="https://github.com/shlinkio/shlink-common/blob/master/src/Middleware/CloseDbConnectionMiddleware.php">shlink-common</a></p></blockquote><p>This middleware also does two more things (this time, after calling the next middleware on the stack, and making sure it does it even if an exception is thrown).</p><ul><li>It first closes the database connection. By doing it so, we make sure the <code>EntityManager</code> will reconnect the next time it needs to interact with the database, and therefore, we avoid the &quot;expired connection&quot; issue.</li><li>Then it clears the <code>EntityManager</code> itself. This avoids memory leaks, and also prevents that any orphan/non-flushed entity &quot;transcends&quot; to the next request, solving the first problem.</li></ul><h3>Further considerations</h3><p>This approach has been working well so far, but it&#x27;s important to assume that the <code>EntityManager</code> was not really designed for this non-blocking kind of context.</p><p>You need to know that the worker making use of it will not be able to serve any request until the <code>EntityManager</code> finishes its job. Because of this you might want to increase the number of swoole workers.</p><p>Also, closing the DB connection on every request is not the most optimal approach. It would be perfect to have a connection pool that was able to recreate connections when expired, and to keep them open as long as possible for faster operations. However, the <code>EntityManager</code> was not designed for that, so it&#x27;s better to close it.</p><p>You also need a <code>callable</code> to pass to the <code>ReopeningEntityManager</code>. The way you solve this depends on your implementation and the dependencies you use.</p><p>In my case, in Shlink I make use of the <code>ServiceManager</code>, so I have a delegator factory which takes the actual factory and passes it to the <code>ReopeningEntityManager</code>:</p><pre><pre><code class="language-php">&lt;?php

declare(strict_types=1);

namespace Shlinkio\Shlink\Common\Doctrine;

use Psr\Container\ContainerInterface;

class ReopeningEntityManagerDelegator
{
    public function __invoke(ContainerInterface $container, string $name, callable $createEm): ReopeningEntityManager
    {
        return new ReopeningEntityManager($createEm);
    }
}
</code></pre></pre><blockquote><p>You can find the actual code in <a target="_blank" rel="noopener noreferrer" href="https://github.com/shlinkio/shlink-common/blob/master/src/Doctrine/ReopeningEntityManagerDelegator.php">shlink-common</a>.</p></blockquote><h3>Conclusion</h3><p>I wanted to write this article as a recap for myself too, since I had to ask and investigate many times, and I couldn&#x27;t find a single source of truth explaining everything.</p><p>I hope that, if you ended up here, this article served you well.</p>

How to properly handle a doctrine entity manager on an expressive application served with swoole

<p>For a long time, I have been trying to include tests in every project in which I&#x27;ve worked on.</p><p>There are several types of automated tests (or what should actually be called <a target="_blank" rel="noopener noreferrer" href="https://abstracta.us/insights/guide-continuous-testing/automated-checks">automated checks</a>). From unit tests, integration and functional tests, to end-to-end tests.</p><p>Each one of them differs from the rest by the scope they try to cover. From small units of code which are tested completely detached from external dependencies, to a whole app which is tested as a black box like if an end consumer was using it.</p><p>I&#x27;m not going to deeply discuss the semantics behind this, or where an integration test ends and an end-to-end test starts, because it&#x27;s quite frequently a blurry line.</p><p>I want to focus on unit tests, and a frequently used practice (even in my own tests), which I have read (and felt) several times, it might not be the best approach.</p><blockquote><p>This article is not focused on any particular technology, since I have found this in a lot of different projects.</p></blockquote><h3>What&#x27;s a unit test</h3><p>According to <a target="_blank" rel="noopener noreferrer" href="https://en.wikipedia.org/wiki/Unit_testing">Wikipedia</a>, unit testing is a &quot;method by which individual units of source code [...] are tested to determine whether they are fit for use&quot;.</p><p>While this might look like a clear definition, it&#x27;s actually quite open because, what&#x27;s a &quot;unit&quot; in the context of unit testing?</p><p>Very often, in object oriented programming projects, people take a class as a unit to test, and create a unit test for every class. In other paradigms, like functional programming, you might consider a function as the unit to be tested, or a set of functions which you have decided to put together in a module.</p><p>This is not really important for the purpose of this article. What&#x27;s really important is to take into account that, in order to properly &quot;unit test&quot; a &quot;unit of source code&quot;, you have to do it by isolating it from any dependency of that unit.</p><p>One of the better ways to achieve this is by following the <strong><a target="_blank" rel="noopener noreferrer" href="https://en.wikipedia.org/wiki/Dependency_inversion_principle">Dependency Injection Principle</a></strong>. Without it you will probably end up trying to hack yourself in order to detach a &quot;unit&quot; from its dependencies.</p><blockquote><p>You can find other articles about <a href="/tag/dependency-injection/">Dependency Injection</a> in my blog.</p></blockquote><h3>Replacing dependencies</h3><p>A very frequent practice when unit testing a unit of source code is to replace its dependencies with <a target="_blank" rel="noopener noreferrer" href="https://en.wikipedia.org/wiki/Test_double">test doubles</a>, in order to properly isolate every unit when testing it.</p><p>Test doubles are basically objects compatible with the dependencies of the subject under test, that are created just for the purpose of the test and have some useful capabilities, like capturing how they have been called, or what should they return when called.</p><p>When you use one of those test doubles to assert how they were called as part of the test itself, you are using them as &quot;spies&quot;.</p><h3>Over-trusting spies</h3><p>All this introduction and contextualization had a single purpose.</p><p>I find myself (and others) in the situation in which you prepare a test double to behave in a certain way, then you call your subject under test, and then assert that your expectations on how the test double was called are correct, by spying on it.</p><p>This sometimes feels wrong, since it seems you are testing the test double/s instead of the subject under test.</p><p>I have read many times that, in a unit test, we should not actually know the internal implementation of the subject under test, but only test that, based on certain input, the expected output is returned (so, trust its public API).</p><p>However, there are cases in which some function/method does not really have any output, and we can only verify everything is going right by spying on the test doubles.</p><p>So, at the end of the day, I have mixed feelings about this practice.</p><h3>Conclusion</h3><p>Sadly, I cannot state a clear conclusion. This is actually an open article, and I would love to get your point of view in the form of a <a href="#comments-box">comment</a>.</p><p>It would be great to see how others face this, if you use other kinds of test doubles instead of spies, or if you are just ok with the implications.</p>

Is spying on mocks a bad practice for unit tests?

<p>A couple hours ago I have released the seventh major version of a module I created more than 4 years ago.</p><div></div><p>It was born as an abstraction to send emails in Zend Framework 2 applications, but trying to make the process simpler than directly working with the lower-level zend/mail component.</p><p>I initially created it to use it in my own project, but at some point decided to publish it as a packagist package to ease others to use it.</p><p>The module used to receive more updates in the beginning, but the number of changes decreased with time.</p><p>The thing is that there were a lot of things I wanted to do, but never had the time. It goes without saying that 4 years ago I didn&#x27;t have the knowledge I have today (I hope 4 years from now I see my current self the same way), and the package had some design problems that needed to be fixed.</p><p>In this post I&#x27;m going to explain the changes that come with this new version, and the reason they were made.</p><h3>Stateless services</h3><p>Business services have to be, by definition, stateless. In AcMailer, that wasn&#x27;t the case.</p><p>I made a mistake when designing the <code>AcMailer\Service\MailService</code> class, and wrapped the <code>Message</code> object to be sent inside of it.</p><p>That made the service to depend on the email data. That was a problem, when you wanted to send different emails on the same request, or even send the same email more than once.</p><p>It needed a few internal ugly tricks to ensure headers were not duplicated and things like that.</p><p>In this version the <code>AcMailer\Service\MailService</code> is stateless. It is just responsible of sending emails, and emails are passed or built at runtime. You can send any number of emails or send them as many times as you want. No side effects.</p><h3>Real compatibility with expressive</h3><p>The module was already including a <code>ConfigProvider</code> for Zend Expressive, but it was not very functional.</p><p>Yes, it was exposing the configuration to expressive apps, but the user was responsible of orchestrating and creating everything.</p><p>Also, the module was tightly coupled with zendframework components that are not usually used in expressive, making it harder to integrate.</p><p>This release reduces the number of dependencies to the bare minimum, and provides real compatibility with expressive, allowing any of their renderers to be used to render emails, while keeping backward compatibility as much as possible with the way things used to be.</p><h3>Emails can be preconfigured</h3><p>As I&#x27;ve mentioned above, emails are no longer part of the service.</p><p>Now, emails can be preconfigured with a name, the same way services are. Then, you can use any of the service instances to send them by just referencing to them by their name.</p><p>A new service, the <code>EmailBuilder</code>, will create those emails and let the mail service send them.</p><p>It is also possible to extend emails to reuse parts that are equal, the same way it is possible with mail services.</p><h3>Code quality improved</h3><p>As I&#x27;ve said, I want to think my programming skills have been improved in the last four years.</p><p>I was seeing a lot of parts of the code with the knowledge that they weren&#x27;t fulfilling best coding practices, like clean code or object calisthenics, and that the cyclomatic complexity was high.</p><p>I have refactored a lot of parts of the code, and the result is much better now. The code is cleaner and easier to maintain. No more <code>if/else</code> all over the place.</p><p>I have also forced a stricter coding standard that extends PSR-2.</p><h3>Tests rewritten</h3><p>As part of this code quality improvement, I have rewritten almost all unit tests.</p><p>They are simpler now, and make use of data providers, which has reduced code duplication, and phpspec/prophecy, which allowed me to drop all custom mocks (I used to build my own mocks and stubs).</p><p>The number of tests has been reduced, and they are now faster to run.</p><h3>Goodbye PHP 5</h3><p>I have added support for PHP 7.2, and dropped support for PHP 5. The code now has stricter type hints and is more predictable.</p><h3>Meaningful exceptions</h3><p>I have included more package exceptions. They are now better used, and the semantics are clearer.</p><p>Also, exception messages include more information now, and explain how to fix the problem when possible.</p><h3>Dropped controller plugin</h3><p>I used to include a controller plugin to use with Zend MVC controllers. I have completely removed it in this version.</p><p>I want to promote constructor dependency injection, and controller plugins allow to pseudo-magically access external services, so I have decided to remove it.</p><p>Also, controllers are not probably the best place to send emails.</p><p>And finally, it made no sense in a zend expressive context, so ultimately I could create a separate package to bring back the controller plugin, but not include it in the main module.</p><h3>Upgrading</h3><p>Sadly, most of these changes require the introduction of BC breaks. That&#x27;s why this version increases the major version number.</p><p>I have tried to properly document how to upgrade to this version, by including an <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya/ZF-AcMailer/blob/master/UPGRADE.md#upgrade-from-5x6x-to-7x">UPGRADE.md</a> document.</p><p>I have also created a small console tool that currently allows to migrate from the old configuration to the new structure, but will probably include more features in the future. <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya/zf-acmailer-tooling">https://github.com/acelaya/zf-acmailer-tooling</a></p><h3>Conclusion</h3><p>And that&#x27;s probably it.</p><p>I have updated the module, improved the code, and made it worthy of modern Expressive and MVC applications. </p>

AcMailer 7.0, the most important release in a long time

<p>At some point, any enterprise project will probably need a message queue.</p><p>A message queue is used to publish information (usually known as <strong>messages</strong>) that a different &quot;node&quot; (usually known as <strong>worker</strong>) will consume in order to perform a specific action.</p><p>It is frequently used in web applications to pass information to background workers that consume the queue and perform long tasks, but it is also an important part when applying concepts like <a target="_blank" rel="noopener noreferrer" href="https://martinfowler.com/eaaDev/EventSourcing.html">Event Sourcing</a> to your architecture.</p><p>It is also really important when working with microservices, since it is a way to enable data exchange between each service.</p><p>Whatever the case, it is very likely that you will eventually need to decide which message queue to use.</p><h3>Why AWS Simple Queue Service</h3><p>In my company we had to decide this some time ago.</p><p>We started testing different services, seeing what their strengths and weaknesses were.</p><p>If I remember correctly, we tested <a target="_blank" rel="noopener noreferrer" href="https://www.rabbitmq.com/">RabbitMQ</a>, <a target="_blank" rel="noopener noreferrer" href="https://kr.github.io/beanstalkd/">Beanstalkd</a>, <a target="_blank" rel="noopener noreferrer" href="https://redis.io/">Redis</a> and <a target="_blank" rel="noopener noreferrer" href="https://aws.amazon.com/sqs/">AWS Simple Queue Service</a> (<strong>SQS</strong> from now on).</p><p>The conclusion was that RabbitMQ is the one with the more features, by far. However, it is also the most complicated to configure and interact with.</p><p>Also, we would have to maintain the RabbitMQ clusters ourselves (the same happens with Beanstalkd).</p><p>Since we work with AWS, we decided to give <strong>SQS</strong> a try, and its simplicity convinced us.</p><p>It is super simple to create a new queue, and using one of their SDKs, you can interact with it in minutes.</p><p>Also, the price is absurdly cheap. It is virtually free for &quot;small&quot; amounts of requests (and when I say small, I mean that performing 1 request to their API every 20 seconds during 1 year costs about $0.30 at the end of the year).</p><p>It is by far cheaper than maintaining your own instances with a different service, and I&#x27;m not counting the cost in time you will have to invest in maintaining those servers.</p><h3>The &quot;small&quot; problem with SQS</h3><p>One of the most interesting features with RabbitMQ is that you can open one socket with the queue server, and once a new message gets in, the worker is &quot;notified&quot; and the message can be consumed. This way, you have a process which is always running, listening for a queue, and processing messages as soon as possible.</p><p>This is usually the desired behavior. You don&#x27;t want any delay on processing messages (or the delay should be as short as possible).</p><p>On the other hand, <strong>SQS</strong> bills by API request. This means that the worker has to manually check if there&#x27;s any message in the queue, in small intervals.</p><p>Our first approach was configuring cron jobs in our workers, so that they could check if there were any message in the queue, and process all of them, if any.</p><p>This was problematic, since it applies a delay of up to one minute (you can&#x27;t configure a cron to be run with an interval smaller than that), which is not desirable, particularly when the job takes 5-10 seconds to complete. Adding an extra 600% of waiting time can affect the user experience, or have other side effects, depending on the task.</p><h3>The long polling to the rescue</h3><p>The first solution that came to our mind was making the workers run requests on an infinite loop, but that&#x27;s not a very clean approach, and will result in our workers being at a 100% of CPU usage all the time.</p><p>We started investigating and found out about a feature in <strong>SQS</strong> called <a target="_blank" rel="noopener noreferrer" href="https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-long-polling.html">long polling</a>. It lets you tell the queue to wait up to 20 seconds before returning a response, if the message queue is empty, and if during that time a new message enters the queue, return a response immediately.</p><p>Using it, you can make a worker continuously perform requests at 20 second intervals, but if a message is in the queue, the response will be returned immediately.</p><p>The final behavior is very similar to a socket, in which you can process a message as soon as it enters the queue, and the worker does not consume any resource while it is waiting for a response.</p><h3>Configure a queue with long polling</h3><p>There are two ways of configuring the long polling. You can do it in AWS, and make the queue always have it, or you can do it client-side, and add a <code>WaitTimeSeconds</code> param with the time in seconds (with a maximum value of 20 seconds).</p><p>The second option is very easy to implement when using any of the official SDKs, and is more flexible, since you can decide when to wait for a message and when to fail immediately when the queue is empty.</p><p>The first one is very easy too. Just set a value for the &quot;Receive Message Wait Time&quot; param, when configuring the queue.</p><p><img src="/assets/img/sqs-socket/receive-message-wait-time.png" alt="SQS Receive Message Wait Time"/></p><p>That should be all, but there&#x27;s one <strong>important</strong> consideration.</p><p>If you have several workers consuming the same queue with long polling and one message enters the queue, all the workers will receive it until one of them deletes it. This is usually problematic, since it could lead to one task being processed more than once.</p><p>In order to prevent this, you should set a small value in the &quot;Default Visibility Timeout&quot; param, which tells <strong>SQS</strong> to deliver the message just to one consumer, and wait that amount of time before delivering it to the rest.</p><p>This way, you can make one of the workers receive the message, delete it from the queue, and then process it, and that will prevent other workers from receiving it.</p><p>Usually, setting a value of 3-5 seconds should be more than enough for the first worker to remove it from the queue. However, if you expect your workers to need a longer time, just increase the value.</p><p>Remember, that value will delay delivering the message to all the workers <strong>but the first</strong> that gets it.</p><h3>Conclusion</h3><p>We have seen an efficient way of working with <strong>SQS</strong>, the most simple, yet powerful message queue.</p><p>If you have more complex needs, it might end being too simple, but if not, it is possible to tweak it enough to use it on large applications and services.</p>

How to simulate a socket connection with AWS Simple Queue Service

<div class="well well-sm"><b>Update 2017-10-18</b>: After reading this article, I recommend you to read the <a href="#comment-3572607201">comment from <b>Rasmus Schultz</b></a>. It is very clarifying, and might make you think twice if this is really the best approach.</div><p>Lately, I&#x27;ve been digging a lot in different ways of improving software architecture. Mainly subjects like <a target="_blank" rel="noopener noreferrer" href="https://8thlight.com/blog/uncle-bob/2012/08/13/the-clean-architecture.html">Clean Architecture</a>, <a target="_blank" rel="noopener noreferrer" href="https://en.wikipedia.org/wiki/Domain-driven_design">Domain Driven Design</a>, and such.</p><p>Those topics cover a lot of advanced and complex practices, but today, I want to talk about a simpler subject. What is the best approach to pass data from outer layers of the application (actions, controllers, async jobs, CLI commands...) to services that are part of the use case layer, by taking advantage of some of the practices promoted by those subjects.</p><p>That&#x27;s a task which is present in any kind of application, and is very important to get properly done. You usually need to get data from different origins (a HTTP request, the input of the command line...), filter and validate it, and then use it to perform some kind of task.</p><p>Not doing it in the correct way could cause inconsistencies, or duplications in your codebase.</p><h3>My previous attempts</h3><p>First of all, I want to start by talking about some of the approaches I have followed in the past, which I felt were not 100% correct, and have led me to a better one.</p><p>My main doubt has always been what&#x27;s the right place to filter and validate data. And that&#x27;s what I asked about a year ago on twitter.</p><div></div><p>The tweet received a lot of good answers, but my knowledge wasn&#x27;t mature enough at the moment, and I couldn&#x27;t &quot;digest&quot; it (I suppose).</p><p>Since then, these have been my approaches:</p><ul><li>Validate data in outer layers and pass it already validated to services. That decouples the service from the validation task, but forces us to duplicate the validation if we share some business logic between a CLI command and an HTTP action (for example).</li><li>Having some sort of validation service that wraps the validation logic, and inject it in elements that need to validate. Solves previous problem, but it is not something that can be easily handled, and also, increases the number of dependencies of actions and CLI commands.<br/>
Also, that new service will soon end up breaking the <a target="_blank" rel="noopener noreferrer" href="https://en.wikipedia.org/wiki/Single_responsibility_principle">Single Responsibility Principle</a>, or you will have to create a lot of services.</li><li>Pass raw params to Services and perform validation there. This also solves the duplication problem, but creates a weird flow, since we have to treat raw data from HTTP or CLI, cast it and check for their existence (which should be part of validation), then pass the result to the Service, and then, make the service again convert received params into some sort of data structure that can be validated.<br/>
Another approach would be make the service directly receive a raw data structure, like an array, but that completely hides the purpose of the service, which is no longer strict enough.</li></ul><h3>Better approach</h3><p>We have seen the problems caused by previous approaches, so we need a better solution, and some of the answers to my tweet include it. <strong>Use value objects for data exchange</strong>.</p><p>Domain Driven Design (DDD) tells that you should use DTOs (data transfer objects) to exchange only the exact needed params with services.</p><p>A value object is an immutable object that can be used to exchange data, which also includes the minimum validation logic to ensure data consistency.</p><p>If we pass raw data from outer layers to a newly created value object, and then pass that value object to services, we ensure services always receive valid data, we avoid duplication and we also remove the validation logic from outer layers elements, without increasing the number of dependencies.</p><p>Also, since the value object exposes very specific params, the intent of a service that expects that value object is very clear.</p><p>All problems solved.</p><h3>Case study</h3><p>Ok, all that theory looks good, but how do we really apply this in the real world?</p><p>Let&#x27;s propose an example that we can use to apply the previous approach. I&#x27;m sure you have implemented something like this a lot of times.</p><p>Imagine we have a web application with an endpoint which is used by users to change their password.</p><p>The endpoint expects a POST request which receives the old password, the new password and a confirmation of the new password (to prevent typos).</p><p>In the HTTP context, the user will be identified by some sort of session system, so there&#x27;s no need to provide any kind of user identifier.</p><p>All provided data needs to be filtered and validated, checking that both the new password and the confirmation password are equal, and that they follow a minimum complexity rule which forces the user to use at least 10 characters that include letters and numbers.</p><p>All three values will be filtered with <code>trim</code> and <code>strip_tags</code>.</p><h4>The value object</h4><p>We will create a value object that will wrap all needed information so that the service can perform the &quot;change password&quot; operation.</p><p>It will also validate all proposed rules when created, and throw an exception if anything fails.</p><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App\Model;

use App\Exception\ValidationException;
use App\Validation\UserPasswordValidator;

final class UserPassword
{
    private $userId;
    private $newPassword;
    private $currentPassword;

    public function __construct(string $userId, string $currentPassword, string $newPassword, string $confirmPassword)
    {
        $this-&gt;validate($userId, $currentPassword, $newPassword, $confirmPassword);
    }

    public static function fromRawData(array $data): self
    {
        return new self(
            $data[&#x27;userId&#x27;] ?? &#x27;&#x27;,
            $data[&#x27;currentPassword&#x27;] ?? &#x27;&#x27;,
            $data[&#x27;newPassword&#x27;] ?? &#x27;&#x27;,
            $data[&#x27;confirmPassword&#x27;] ?? &#x27;&#x27;
        );
    }

    private function validate(
        string $userId, 
        string $currentPassword, 
        string $newPassword, 
        string $confirmPassword
    ): void {
        $validator = new UserPasswordValidator([
            &#x27;userId&#x27; =&gt; $userId,
            &#x27;currentPassword&#x27; =&gt; $currentPassword,
            &#x27;newPassword&#x27; =&gt; $newPassword,
            &#x27;confirmPassword&#x27; =&gt; $confirmPassword,
        ]);
        if (! $validator-&gt;isValid()) {
            throw new ValidationException(&#x27;Provided data is invalid&#x27;, $validator-&gt;getErrors());
        }

        // If validation passed, get filtered values
        $this-&gt;userId = $validator-&gt;getFilteredValue(&#x27;userId&#x27;);
        $this-&gt;newPassword = $validator-&gt;getFilteredValue(&#x27;newPassword&#x27;);
        $this-&gt;currentPassword = $validator-&gt;getFilteredValue(&#x27;currentPassword&#x27;);
    }

    public function getUserId(): string
    {
        return $this-&gt;userId;
    }

    public function getNewPassword(): string
    {
        return $this-&gt;newPassword;
    }

    public function getCurrentPassword(): string
    {
        return $this-&gt;currentPassword;
    }
}
</code></pre></pre><blockquote><p>I have avoided the validation part, because it depends on the package used for that, but you get the idea.</p></blockquote><p>Let&#x27;s explain this class.</p><p>It is a final class, which only exposes three getters, so consumers will only be able to access those specific params.</p><p>It doesn&#x27;t expose the confirmPassword, because it is only used for validation. Once validated that both <code>newPassword</code> and <code>confirmPassword</code> are equal, we don&#x27;t need that value anymore.</p><p>As soon as the object is created, it filters and validates provided data, throwing an exception if validation fails. Otherwise, internal properties are set with already filtered values.</p><p>It also includes a <a target="_blank" rel="noopener noreferrer" href="http://verraes.net/2014/06/named-constructors-in-php/">named constructor</a> that allows this object to be created from a set of raw data, which will be very handful in several contexts. That method checks that every property is set, and passes an empty value otherwise (the empty values won&#x27;t pass validation, so we don&#x27;t need to duplicate the check there too).</p><h4>Consuming the value object</h4><p>Now let&#x27;s see how the service would consume this value object. This is going to be more pseudocode than actual code, so do not take it to the letter.</p><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App\Service;

use App\Model\ChangePasswordResult;
use App\Model\UserPassword;

class PasswordChanger implements PasswordChangerInterface
{
    public function changeUserPassword(UserPassword $userPassword): ChangePasswordResult
    {
        // Find the user somehow
        $user = $this-&gt;findUserById($userPassword-&gt;getUserId());
        
        // Make sure current password is correct
        if (! \password_verify($userPassword-&gt;getCurrentPassword(), $user-&gt;getPassword())) {
            // Throw some sort of exception or return an unsuccessful result
        }
        
        // Update the password on the user
        $user-&gt;setPassword(\password_hash($userPassword-&gt;getNewPassword(), PASSWORD_DEFAULT));
        
        // Finally return a successful result
        return new ChangePasswordResult($user);
    }
}
</code></pre></pre><p>As you can see, the service implementation is very simple when using this approach, because passing a single <code>UserPassword</code> object we have all the needed information to find the user, check if the password is correct, and then set the new password.</p><p>We can be sure that provided data is perfectly valid, so the service doesn&#x27;t need to know anything about validation.</p><h4>Passing the value object</h4><p>Finally, we need to know how outer layers create the value object and pass it to the service.</p><p>Any PHP application has some sort of HTTP abstraction, where body params can be read from the request. Let&#x27;s imagine we are working on a psr-7/psr-15 app, and this is our <code>ChangeUserPasswordAction</code>.</p><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App\Action;

use App\Exception\ValidationException;
use App\Model\UserPassword;
use App\Service\PasswordChangerInterface;
use Interop\Http\ServerMiddleware\DelegateInterface;
use Interop\Http\ServerMiddleware\MiddlewareInterface;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;

class ChangeUserPasswordAction implements MiddlewareInterface
{
    /**
     * @var PasswordChangerInterface 
     */
    private $passwordChanger;
    
    public function __construct(PasswordChangerInterface $passwordChanger)
    {
        $this-&gt;passwordChanger = $passwordChanger;
    }
    
    public function process(ServerRequestInterface $request, DelegateInterface $delegate): ResponseInterface
    {
        try {
            // Get request body, and include currently logged user ID
            $data = $request-&gt;getParsedBody();
            $data[&#x27;userId&#x27;] = $request-&gt;getAttribute(&#x27;currentUserId&#x27;);
            $userPassword = UserPassword::fromRawData($data);
            
            $result = $this-&gt;passwordChanger-&gt;changeUserPassword($userPassword);
            
            // Based on the result, return a success or error response...
        } catch (ValidationException $e) {
            // Return an error response...
        }
    }
}
</code></pre></pre><p>And that&#x27;s it. Really simple.</p><p>The action just needs to catch the possible validation exception that could be thrown when creating the <code>UserPassword</code> object, and then pass that object to the service and handle the result.</p><p>Now let&#x27;s imagine our app has a CLI command that is used to change any user password, to which we have to pass the same set of data (old password, new password...). It is not very likely in this specific case, but there are other operations that are more suitable to be executed from different contexts.</p><p>The command (in pseudocode) could look like this:</p><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App\CLI\Command;

use App\Exception\ValidationException;
use App\Model\UserPassword;
use App\Service\PasswordChangerInterface;

class ChangeUserPasswordCommand
{
    /**
     * @var PasswordChangerInterface 
     */
    private $passwordChanger;
    
    public function __construct(PasswordChangerInterface $passwordChanger)
    {
        $this-&gt;passwordChanger = $passwordChanger;
    }
    
    public function run($input, $output): void
    {
        try {
            $userPassword = new UserPassword(
                $input-&gt;get(&#x27;userId&#x27;),
                $input-&gt;get(&#x27;currentPassword&#x27;),
                $input-&gt;get(&#x27;newPassword&#x27;),
                $input-&gt;get(&#x27;confirmPassword&#x27;)
            );
            
            $result = $this-&gt;passwordChanger-&gt;changeUserPassword($userPassword);
            
            // Based on the result, output a success or error message...
        } catch (ValidationException $e) {
            // Output an error message...
        }
    }
}
</code></pre></pre><p>Again, the CLI command implementation is very simple. We just need to create the <code>UserPassword</code> object and pass it to the service, catching any validation exception (and any exception thrown by the service too).</p><h3>Conclusion</h3><p>What I&#x27;ve learned here is that anything can be improved.</p><p>There is no &quot;perfect&quot; way to do anything. You have to do it in the best possible way, but always be opened for improvement.</p><p>Always try to learn from your coworkers and the community as a whole, and keep reading lots of articles and books.</p><p>If you do that, you&#x27;ll end up finding solutions with which you feel comfortable working with.</p>

Properly passing data from outer layers of a PHP application to the use case layer

<p>Earlier last week I found a <a target="_blank" rel="noopener noreferrer" href="https://github.com/WyriHaximus/awesome-phpstorm">github repository</a> which collects different resources related with PhpStorm. Plugins, themes, utilities...</p><p>I found it very interesting, because I think <a target="_blank" rel="noopener noreferrer" href="https://www.jetbrains.com/phpstorm/">PhpStorm</a> is the best PHP IDE by far, and I&#x27;ve been using it on an almost daily basis for the last 4 years.</p><p>The thing is that finding that repository gave me the idea of writing a post explaining the list of third party plugins I use and why, in case somebody is starting to use the IDE and wants some ideas on where to start.</p><p>If you want to get any of them, just search for it inside PhpStorm. It&#x27;s the easiest way to install them.</p><h3>.env</h3><p>If you work with env files in your development process, either with <a target="_blank" rel="noopener noreferrer" href="https://github.com/vlucas/phpdotenv">vlucas/phpdotenv</a> (which comes bundled with laravel) or with <a target="_blank" rel="noopener noreferrer" href="https://symfony.com/doc/current/components/dotenv.html">symfony/dotenv</a>, this extension is very handy.</p><p>It autocompletes environment variables defined in the .env file and the docker-compose.yml file when using the <code>env()</code> or <code>getenv()</code> functions.</p><p>It also displays the value defined for those env variables inside the file.</p><p><img src="/assets/img/phpstorm-plugins/dot-env.png" alt=".env"/></p><blockquote><p>As a tip I will say that the first time I installed this plugin it didn&#x27;t work for me, because I had the .env files associated with the ini file type. Make sure you associate them with the .env type instead to get it working.</p></blockquote><p>Link: <a target="_blank" rel="noopener noreferrer" href="https://plugins.jetbrains.com/plugin/9525--env-files-support">https://plugins.jetbrains.com/plugin/9525--env-files-support</a></p><h3>.ignore</h3><p>This plugin detects ignored files for many types of resources. Git, docker, npm and many more.</p><p>It adds syntax highlight and autocompletion to those files (.gitignore, .hgignore...), displaying which of the ignored files do not exist anymore.</p><p>It also sets a light grey font color in the project explorer for ignored files, so it is easier to &quot;ignore&quot; them.</p><p>Finally, it displays a message at the top of the editor when you have opened an ignored file, so that you know it is not going to affect the corresponding tool.</p><p>Link: <a target="_blank" rel="noopener noreferrer" href="https://plugins.jetbrains.com/plugin/7495--ignore">https://plugins.jetbrains.com/plugin/7495--ignore</a></p><h3>BashSupport</h3><p>If you have to work with shell scripts in any of your projects, this plugin is very useful.</p><p>It adds syntax highlight, autocompletion, quickfixes and refactoring for <code>bash</code> and <code>sh</code>.</p><p>It also allows you to add a missing shebang or even run the script right inside PhpStorm by right-clicking and selecting &quot;Run&quot;.</p><p><img src="/assets/img/phpstorm-plugins/bash-support.png" alt="BashSupport"/></p><p>Link: <a target="_blank" rel="noopener noreferrer" href="https://plugins.jetbrains.com/plugin/4230-bashsupport">https://plugins.jetbrains.com/plugin/4230-bashsupport</a></p><h3>CodeGlance</h3><p>This one os more cool than useful.</p><p>It adds a minimap inside any file editor, similar to the one that was made popular by Sublime text.</p><p>It can be used to get an idea of the size of the file just at a glance.</p><p><img src="/assets/img/phpstorm-plugins/code-glance.png" alt="CodeGlance"/></p><p>Link: <a target="_blank" rel="noopener noreferrer" href="https://plugins.jetbrains.com/plugin/7275-codeglance">https://plugins.jetbrains.com/plugin/7275-codeglance</a></p><h3>PHP Annotations</h3><p>This one is essential if you work with annotations of any kind (doctrine ORM, jms serializer, and such).</p><p>Since PHP does not natively support annotations, everybody that needs that feature uses the package <a target="_blank" rel="noopener noreferrer" href="https://github.com/doctrine/annotations">doctrine/annotations</a>.</p><p>It works really great, but since it works at comment level, it is very easy to break something by accident.</p><p>This plugin adds a lot of features:</p><ul><li>Mark use statements as used when imported for an annotation.</li><li>Refactor or jump to annotation classes.</li><li>Annotation properties autocompletion (and even values, for well known projects like doctrine/orm).</li><li>Auto alias imports.</li><li>Syntax highlight and error management.</li></ul><p>This plugin almost suppresses the possibilities of breaking your code when running an automated use statements optimization or remove part of the annotation by mistake, things that cannot be caught by a unit test.</p><p><img src="/assets/img/phpstorm-plugins/annotations.png" alt="PHP Annotations"/></p><p>Link: <a target="_blank" rel="noopener noreferrer" href="https://plugins.jetbrains.com/plugin/7320-php-annotations">https://plugins.jetbrains.com/plugin/7320-php-annotations</a></p><h3>PHP composer.json support</h3><p>Everybody uses composer for modern PHP projects, so this plugin is a must.</p><p>It autocompletes composer.json blocks, and validates it, but making sure to never suggest a block that&#x27;s already in the file.</p><p>It also displays warnings for common mistakes, like using the dev-master constraint for a dependency.</p><p>It is very useful when you don&#x27;t remember the name of a package, since it autocompletes package names too.</p><p><img src="/assets/img/phpstorm-plugins/composer.png" alt="PHP composer.json support"/></p><p>Link: <a target="_blank" rel="noopener noreferrer" href="https://plugins.jetbrains.com/plugin/7631-php-composer-json-support">https://plugins.jetbrains.com/plugin/7631-php-composer-json-support</a></p><h3>Php Inspections (EA Extended)</h3><p>If I had to uninstall all my plugins but one, this would be the one that I would keep for sure. Probably the best plugin and the one I use the most on any project.</p><p>It adds a huge amount of new inspections to PhpStorm that will greatly improve your code.</p><p>To name some:</p><ul><li>Warn about non-annotated thrown exceptions.</li><li>Warn about known PHP security issues.</li><li>Suggest better or more readable language constructions.</li><li>Suggest about more efficient ways of perform known tasks.</li><li>Warn about ugly code smells.</li><li>Warn about suspicious code blocks.</li></ul><p>And things like that. It is impossible to list all the things this plugin is able to inspect. I recommend you to install it and test it, because it really improves your productivity.</p><p>Link: <a target="_blank" rel="noopener noreferrer" href="https://plugins.jetbrains.com/plugin/7622-php-inspections-ea-extended-">https://plugins.jetbrains.com/plugin/7622-php-inspections-ea-extended-</a></p><h3>PHPUnit Enhancement</h3><p>I discovered this plugin in the list I mentioned at the beginning of this article, so I have been using it for a short time.</p><p>I still have to tweak it to fit my needs, but it is better than anything anyway.</p><p>It mainly tells PhpStorm the type of mocked objects (either by PHPUnit&#x27;s mocks or by PHPSpec&#x27;s prophecies). This way, when you try to mock a method, you get autocompletion, and also, If later on you want to refactor that method or find their usages, it will find the mock too.</p><p>The problem is that, for example, you might create a prophecy of a method that expects more than one argument or has a specific type hint, and you pass it something like <code>Argument::cetera()</code>. That makes it mark an error because the method expects something else.</p><p>Apart from that, I think it&#x27;s worth it.</p><p>Link: <a target="_blank" rel="noopener noreferrer" href="https://plugins.jetbrains.com/plugin/9674-phpunit-enhancement">https://plugins.jetbrains.com/plugin/9674-phpunit-enhancement</a></p><h3>Swagger plugin</h3><p>When you work on an API that needs to be documented, swagger is a really good tool.</p><p>This plugin adds autocompletion and inspections on swagger docs, either yaml or JSON, so that you don&#x27;t need to wait for external tools to validate your files.</p><p><img src="/assets/img/phpstorm-plugins/swagger.png" alt="Swagger plugin"/></p><p>Link: <a target="_blank" rel="noopener noreferrer" href="https://plugins.jetbrains.com/plugin/8347-swagger-plugin">https://plugins.jetbrains.com/plugin/8347-swagger-plugin</a></p><h3>Conclusion</h3><p>That&#x27;s all the third party plugins I use at the moment of writing this article.</p><p>If in the future I add any other, I&#x27;ll update this list.</p><p>If you know of any cool plugin that&#x27;s not listed here, just add a comment to the article so that other can be aware of its existence.</p>

The PhpStorm plugins of my choice

<p>I think it is doubtless that modern PHP embraces SOLID principles, and therefore, <a target="_blank" rel="noopener noreferrer" href="https://en.wikipedia.org/wiki/Dependency_injection">dependency injection</a>.</p><p>That&#x27;s why every modern PHP application needs a dependency injection container to deal with it.</p><p>There are several options out there, depending on the way you like to work. Every container has a slightly different approach.</p><p>My choice is <a target="_blank" rel="noopener noreferrer" href="https://docs.zendframework.com/zend-servicemanager/">zend-servicemanager</a>, it is the one that better suits me.</p><p>Other containers rely on auto wiring and auto discovery in order to know which dependencies need to be injected on every service, and I think that leads to errors when an application grows.</p><p>I like <strong>zend-servicemanager</strong> because it is explicit, and you are always in control of what&#x27;s done, without loosing flexibility in the process.</p><p>However, I have to recognize that it comes with a prize.</p><h3>Factories everywhere</h3><p>Since this container expects you to define factories for every service, you usually end up writing, testing and maintaining a lot of factories that doesn&#x27;t add value to the application.</p><p>That&#x27;s why it is <strong>so important</strong> to properly reuse factories when possible, not only because you will have to maintain less classes, but because the ServiceManager will instantiate less objects at runtime when it can reuse a factory.</p><p>This article is born because of the question of a reader of this blog, which asked me what did I mean with the <em>&quot;redundancy mitigated by reusing same factory&quot;</em> sentence, in one of my <a href="/2016/07/21/project-scalability-with-zend-expressive/">Zend Expressive articles</a>.</p><div></div><p>I created a <a target="_blank" rel="noopener noreferrer" href="https://gist.github.com/acelaya/41cf7457c2dbc434c4bb919a21e002da">gist</a> with some of the approaches to reuse factories, but I think it deserves a blog post, so here it is.</p><h3>Shared dependencies</h3><p>The simplest situation to reuse a factory is when you have more than one service with the same dependencies.</p><p>This situation can be solved with an abstract factory, but you can also use a concrete factory, which is more efficient.</p><p>Let&#x27;s imagine you are using the <a target="_blank" rel="noopener noreferrer" href="https://docs.zendframework.com/zend-db/">zend-db</a> package to deal with persistence, and you have created one <code>TableGateway</code> class for every table in your database.</p><p>All of the <code>TableGateways</code> depend on a <code>Zend\DB\Adapter\AdapterInterface</code> to be injected on them, so creating a different factory for every one of them would be a waste of time.</p><p>Instead, you just need to create a factory like this:</p><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App;

use Interop\Container\ContainerInterface;
use Zend\DB\Adapter\AdapterInterface;

class TableGatewayFactory
{
    public function __invoke(ContainerInterface $container, string $requestedName)
    {
        $adapter = $container-&gt;get(AdapterInterface::class);
        return new $requestedName($adapter);
    }
}
</code></pre></pre><p>Then, register your table gateways using the FQCN:</p><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App;

return [

    &#x27;service_manager&#x27; =&gt; [
        &#x27;factories&#x27; =&gt; [
            UserTableGateway::class =&gt; TableGatewayFactory::class,
            ArticleTableGateway::class =&gt; TableGatewayFactory::class,
            FooTableGateway::class =&gt; TableGatewayFactory::class,
            // ...
        ],
    ],

];
</code></pre></pre><p>If you prefer using an abstract factory, just do this:</p><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App;

use Interop\Container\ContainerInterface;
use Zend\DB\Adapter\AdapterInterface;
use Zend\DB\TableGateway\TableGateway;
use Zend\ServiceManager\Factory\AbstractFactoryInterface;

class TableGatewayAbstractFactory implements AbstractFactoryInterface
{
    public function canCreate(ContainerInterface $container, $requestedName)
    {
        return is_subclass_of($requestedName, TableGateway::class);
    }
    
    public function __invoke(ContainerInterface $container, $requestedName)
    {
        $adapter = $container-&gt;get(AdapterInterface::class);
        return new $requestedName($adapter);
    }
}
</code></pre></pre><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App;

return [

    &#x27;service_manager&#x27; =&gt; [
        &#x27;abstract_factories&#x27; =&gt; [
            TableGatewayAbstractFactory::class,
        ],
    ],

];
</code></pre></pre><h3>Using ConfigAbstractFactory</h3><p>The zend-servicemanager v3.2 introduced a built-in factory that can inject dependencies on services based on configuration.</p><p>This is probably one of the better ways to reuse factories (indeed, you won&#x27;t have to write any factory, since this one is included in the package).</p><p>In 80% of the cases (if not more), a factory basically consists on grabbing some dependencies from the container, and creating a new instance of an object where those dependencies are injected. In those cases the <code>ConfigAbstractFactory</code> is perfect.</p><p>When using this factory, you just need to define a configuration block where you define the service names on which every other service depends.</p><p>For example, if we have this code base:</p><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App;

class OtherService
{
    public function __construct()
    {
        // No dependencies
    }
}

class BazService
{
    public function __construct()
    {
        // No dependencies
    }
}

class BarService
{
    public function __construct(BazService $baz)
    {
        // Depends on BazService
    }
}

class FooService
{
    public function __construct(BarService $baz, OtherService $other)
    {
        // Depends both on BarService and OtherService
    }
}
</code></pre></pre><p>We just need to define a configuration like this:</p><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App;

use Zend\ServiceManager\AbstractFactory\ConfigAbstractFactory;
use Zend\ServiceManager\Factory\InvokableFactory;

return [
    &#x27;service_manager&#x27; =&gt; [
        &#x27;factories&#x27; =&gt; [
            FooService::class =&gt; ConfigAbstractFactory::class,
            BarService::class =&gt; ConfigAbstractFactory::class,
            BazService::class =&gt; InvokableFactory::class,
            OtherService::class =&gt; InvokableFactory::class,
        ],
    ],
    
    ConfigAbstractFactory::class =&gt; [
        BarService::class =&gt; [BazService::class],
        FooService::class =&gt; [BarService::class, OtherService::class],
    ],
];
</code></pre></pre><p>Then, the <code>ConfigAbstractFactory</code> will look for all the services on which requested service depends, and inject them into it.</p><p>Also, the package includes a binary that can be used to generate the <code>ConfigAbstractFactory</code> config for a service, so you won&#x27;t even need to write that.</p><p>This factory can be registered as an abstract factory too (indeed, it <strong>is</strong> an abstract factory), but as mentioned above, it is less efficient, and I prefer this approach.</p><p>You have an in-detail documentation of this factory here: <a target="_blank" rel="noopener noreferrer" href="https://docs.zendframework.com/zend-servicemanager/config-abstract-factory/">https://docs.zendframework.com/zend-servicemanager/config-abstract-factory/</a></p><h3>Using ReflectionBasedAbstractFactory</h3><p>This factory works similarly to the previous one, but instead of discovering the dependencies to inject based on a configuration array, it uses reflection on requested service.</p><p>This has the small advantage that you don&#x27;t have to specify the dependencies for every service. However, reflection is very inefficient, so this factory is not suited for production, but only for prototyping purposes.</p><p>Also, you need to register services with the same type used in the requested service constructor, so you can&#x27;t type hint to an interface and then inject a service which is registered with an implementation name, or a string which is not even a class name.</p><p>Apart from that, registration is the same as in previous factories:</p><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App;

use Zend\ServiceManager\AbstractFactory\ReflectionBasedAbstractFactory;
use Zend\ServiceManager\Factory\InvokableFactory;

return [

    &#x27;service_manager&#x27; =&gt; [
        &#x27;factories&#x27; =&gt; [
            FooService::class =&gt; ReflectionBasedAbstractFactory::class,
            BarService::class =&gt; ReflectionBasedAbstractFactory::class,
            BazService::class =&gt; InvokableFactory::class,
            OtherService::class =&gt; InvokableFactory::class,
        ],
    ],

];
</code></pre></pre><p>The extended documentation for this factory can be found here: <a target="_blank" rel="noopener noreferrer" href="https://zendframework.github.io/zend-servicemanager/reflection-abstract-factory/">https://zendframework.github.io/zend-servicemanager/reflection-abstract-factory/</a></p><h3>Using acelaya/zsm-annotated-services package</h3><p>Some time ago (when the <code>ConfigAbstractFactory</code> didn&#x27;t exist yet), I created the <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya/zsm-annotated-services">acelaya/zsm-annotated-services</a> package, which provides one factory that can discover the list of dependencies of a service based on an <code>@Inject</code> annotation in its constructor, instead of using a configuration array.</p><p>The first example could be redeclared like this:</p><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App;

use Acelaya\ZsmAnnotatedServices\Annotation\Inject;

class OtherService
{
    public function __construct()
    {
        // No dependencies
    }
}

class BazService
{
    public function __construct()
    {
        // No dependencies
    }
}

class BarService
{
    /**
     * @Inject({BazService::class}) 
     */
    public function __construct(BazService $baz)
    {
        // Depends on BazService
    }
}

class FooService
{
    /**
     * @Inject({BarService::class, OtherService::class}) 
     */
    public function __construct(BarService $baz, OtherService $other)
    {
        // Depends both on BarService and OtherService
    }
}
</code></pre></pre><p>And then, you just need to map the services to the <code>AnnotatedFactory</code> (select the right one, depending on the ServiceManager version)</p><pre><pre><code class="language-php">&lt;?php
declare(strict_types=1);

namespace App;

use Acelaya\ZsmAnnotatedServices\Factory\V3\AnnotatedFactory;
use Zend\ServiceManager\Factory\InvokableFactory;

return [

    &#x27;service_manager&#x27; =&gt; [
        &#x27;factories&#x27; =&gt; [
            FooService::class =&gt; AnnotatedFactory::class,
            BarService::class =&gt; AnnotatedFactory::class,
            BazService::class =&gt; InvokableFactory::class,
            OtherService::class =&gt; InvokableFactory::class,
            
            // You will probably need to define some cache adapter in production
            AnnotatedFactory::CACHE_SERVICE =&gt; SomeCacheFactory::class,
        ],
    ],

];
</code></pre></pre><p>The only drawback of this factory, is that you need to define a cache adapter in production, because processing annotations is very slow (it uses reflection too).</p><p>Here you have the complete documentation: <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya/zsm-annotated-services">https://github.com/acelaya/zsm-annotated-services</a>.</p><p>However, if I were you, I would choose the <code>ConfigAbstractFactory</code> over this one, because using annotations couples the configuration with the service.</p><h3>Conclusion</h3><p>The problem of defining several factories is usually the main argument I hear against using this component, but as you can see, there are several approaches to deal with it, without loosing control over your code base or depending on black magic.</p><p>There are probably other options that I&#x27;ve missed here, so if you know any other approach, just comment this post and I will gladly add it.</p>

Alejandro Celaya | Blog

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