feature #22734 [Console] Add support for command lazy-loading (chalasr)

This PR was merged into the 3.4 branch.

Discussion
----------

[Console] Add support for command lazy-loading

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #12063 #16438 #13946 #21781
| License       | MIT
| Doc PR        | todo

This PR adds command lazy-loading support to the console, based on PSR-11 and DI tags.
(#12063 (comment))

Commands registered as services which set the `command` attribute on their `console.command` tag are now instantiated when calling `Application::get()` instead of all instantiated at `run()`.

__Usage__

```yaml
app.command.heavy:
    tags:
        - { name: console.command, command: app:heavy }
```

This way private command services can be inlined (no public aliases, remain really private).

With console+PSR11 implem only:

```php
$application = new Application();
$container = new ServiceLocator(['heavy' => function () { return new Heavy(); }]);
$application->setCommandLoader(new ContainerCommandLoader($container, ['app:heavy' => 'heavy']);
```

Implementation is widely inspired from Twig runtime loaders (without the definition/runtime separation which is not needed here).

Commits
-------

7f97519 Add support for command lazy-loading

src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md

@@ -18,6 +18,8 @@ CHANGELOG
    `Symfony\Component\Translation\DependencyInjection\TranslationExtractorPass` instead
  * Deprecated `TranslatorPass`, use 
    `Symfony\Component\Translation\DependencyInjection\TranslatorPass` instead
+ * Added `command` attribute to the `console.command` tag which takes the command
+   name as value, using it makes the command lazy
 
 3.3.0
 -----

src/Symfony/Bundle/FrameworkBundle/Console/Application.php

@@ -68,15 +68,7 @@ public function doRun(InputInterface $input, OutputInterface $output)
     {
         $this->kernel->boot();
 
-        $container = $this->kernel->getContainer();
-
-        foreach ($this->all() as $command) {
-            if ($command instanceof ContainerAwareInterface) {
-                $command->setContainer($container);
-            }
-        }
-
-        $this->setDispatcher($container->get('event_dispatcher'));
+        $this->setDispatcher($this->kernel->getContainer()->get('event_dispatcher'));
 
         return parent::doRun($input, $output);
     }
@@ -98,7 +90,13 @@ public function get($name)
     {
         $this->registerCommands();
 
-        return parent::get($name);
+        $command = parent::get($name);
+
+        if ($command instanceof ContainerAwareInterface) {
+            $command->setContainer($this->kernel->getContainer());
+        }
+
+        return $command;
     }
 
     /**
@@ -144,9 +142,15 @@ protected function registerCommands()
             }
         }
 
+        if ($container->has('console.command_loader')) {
+            $this->setCommandLoader($container->get('console.command_loader'));
+        }
+
         if ($container->hasParameter('console.command.ids')) {
             foreach ($container->getParameter('console.command.ids') as $id) {
-                $this->add($container->get($id));
+                if (false !== $id) {
+                    $this->add($container->get($id));
+                }
             }
         }
     }

src/Symfony/Bundle/FrameworkBundle/Tests/Command/RouterDebugCommandTest.php

@@ -77,10 +77,15 @@ private function getKernel()
 
         $container = $this->getMockBuilder('Symfony\Component\DependencyInjection\ContainerInterface')->getMock();
         $container
-            ->expects($this->once())
+            ->expects($this->atLeastOnce())
             ->method('has')
-            ->with('router')
-            ->will($this->returnValue(true))
+            ->will($this->returnCallback(function ($id) {
+                if ('console.command_loader' === $id) {
+                    return false;
+                }
+
+                return true;
+            }))
         ;
         $container
             ->expects($this->any())

src/Symfony/Bundle/FrameworkBundle/Tests/Command/RouterMatchCommandTest.php

@@ -78,8 +78,14 @@ private function getKernel()
         $container
             ->expects($this->atLeastOnce())
             ->method('has')
-            ->with('router')
-            ->will($this->returnValue(true));
+            ->will($this->returnCallback(function ($id) {
+                if ('console.command_loader' === $id) {
+                    return false;
+                }
+
+                return true;
+            }))
+        ;
         $container
             ->expects($this->any())
             ->method('get')

src/Symfony/Bundle/FrameworkBundle/composer.json

@@ -35,7 +35,7 @@
         "fig/link-util": "^1.0",
         "symfony/asset": "~3.3|~4.0",
         "symfony/browser-kit": "~2.8|~3.0|~4.0",
-        "symfony/console": "~3.3|~4.0",
+        "symfony/console": "~3.4|~4.0",
         "symfony/css-selector": "~2.8|~3.0|~4.0",
         "symfony/dom-crawler": "~2.8|~3.0|~4.0",
         "symfony/polyfill-intl-icu": "~1.0",
@@ -64,7 +64,7 @@
         "phpdocumentor/type-resolver": "<0.2.0",
         "phpunit/phpunit": "<4.8.35|<5.4.3,>=5.0",
         "symfony/asset": "<3.3",
-        "symfony/console": "<3.3",
+        "symfony/console": "<3.4",
         "symfony/form": "<3.3",
         "symfony/property-info": "<3.3",
         "symfony/serializer": "<3.3",

src/Symfony/Bundle/SecurityBundle/Resources/config/console.xml

@@ -10,7 +10,7 @@
         <service id="security.console.user_password_encoder_command" class="Symfony\Bundle\SecurityBundle\Command\UserPasswordEncoderCommand">
             <argument type="service" id="security.encoder_factory"/>
             <argument type="collection" /> <!-- encoders' user classes -->
-            <tag name="console.command" />
+            <tag name="console.command" command="security:encode-password" />
         </service>
     </services>
 </container>

src/Symfony/Bundle/WebServerBundle/Resources/config/webserver.xml

@@ -10,21 +10,21 @@
         <service id="web_server.command.server_run" class="Symfony\Bundle\WebServerBundle\Command\ServerRunCommand">
             <argument>%kernel.project_dir%/web</argument>
             <argument>%kernel.environment%</argument>
-            <tag name="console.command" />
+            <tag name="console.command" command="server:run" />
         </service>
 
         <service id="web_server.command.server_start" class="Symfony\Bundle\WebServerBundle\Command\ServerStartCommand">
             <argument>%kernel.project_dir%/web</argument>
             <argument>%kernel.environment%</argument>
-            <tag name="console.command" />
+            <tag name="console.command" command="server:start" />
         </service>
 
         <service id="web_server.command.server_stop" class="Symfony\Bundle\WebServerBundle\Command\ServerStopCommand">
-            <tag name="console.command" />
+            <tag name="console.command" command="server:stop" />
         </service>
 
         <service id="web_server.command.server_status" class="Symfony\Bundle\WebServerBundle\Command\ServerStatusCommand">
-            <tag name="console.command" />
+            <tag name="console.command" command="server:status" />
         </service>
     </services>
 </container>

src/Symfony/Component/Console/Application.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Console;
 
+use Symfony\Component\Console\CommandLoader\CommandLoaderInterface;
 use Symfony\Component\Console\Exception\ExceptionInterface;
 use Symfony\Component\Console\Formatter\OutputFormatter;
 use Symfony\Component\Console\Helper\DebugFormatterHelper;
@@ -64,6 +65,7 @@ class Application
     private $runningCommand;
     private $name;
     private $version;
+    private $commandLoader;
     private $catchExceptions = true;
     private $autoExit = true;
     private $definition;
@@ -96,6 +98,11 @@ public function setDispatcher(EventDispatcherInterface $dispatcher)
         $this->dispatcher = $dispatcher;
     }
 
+    public function setCommandLoader(CommandLoaderInterface $commandLoader)
+    {
+        $this->commandLoader = $commandLoader;
+    }
+
     /**
      * Runs the current application.
      *
@@ -431,6 +438,10 @@ public function add(Command $command)
             throw new LogicException(sprintf('Command class "%s" is not correctly initialized. You probably forgot to call the parent constructor.', get_class($command)));
         }
 
+        if (!$command->getName()) {
+            throw new LogicException(sprintf('The command defined in "%s" cannot have an empty name.', get_class($command)));
+        }
+
         $this->commands[$command->getName()] = $command;
 
         foreach ($command->getAliases() as $alias) {
@@ -451,12 +462,16 @@ public function add(Command $command)
      */
     public function get($name)
     {
-        if (!isset($this->commands[$name])) {
+        if (isset($this->commands[$name])) {
+            $command = $this->commands[$name];
+        } elseif ($this->commandLoader && $this->commandLoader->has($name)) {
+            $command = $this->commandLoader->get($name);
+            $command->setName($name);
+            $this->add($command);
+        } else {
             throw new CommandNotFoundException(sprintf('The command "%s" does not exist.', $name));
         }
 
-        $command = $this->commands[$name];
-
         if ($this->wantHelps) {
             $this->wantHelps = false;
 
@@ -478,7 +493,7 @@ public function get($name)
      */
     public function has($name)
     {
-        return isset($this->commands[$name]);
+        return isset($this->commands[$name]) || ($this->commandLoader && $this->commandLoader->has($name));
     }
 
     /**
@@ -555,7 +570,7 @@ public function findNamespace($namespace)
      */
     public function find($name)
     {
-        $allCommands = array_keys($this->commands);
+        $allCommands = $this->commandLoader ? array_merge($this->commandLoader->getNames(), array_keys($this->commands)) : array_keys($this->commands);
         $expr = preg_replace_callback('{([^:]+|)}', function ($matches) { return preg_quote($matches[1]).'[^:]*'; }, $name);
         $commands = preg_grep('{^'.$expr.'}', $allCommands);
 
@@ -581,12 +596,12 @@ public function find($name)
 
         // filter out aliases for commands which are already on the list
         if (count($commands) > 1) {
-            $commandList = $this->commands;
-            $commands = array_filter($commands, function ($nameOrAlias) use ($commandList, $commands) {
-                $commandName = $commandList[$nameOrAlias]->getName();
+            $commandList = $this->commandLoader ? array_merge(array_flip($this->commandLoader->getNames()), $this->commands) : $this->commands;
+            $commands = array_unique(array_filter($commands, function ($nameOrAlias) use ($commandList, $commands) {
+                $commandName = $commandList[$nameOrAlias] instanceof Command ? $commandList[$nameOrAlias]->getName() : $nameOrAlias;
 
                 return $commandName === $nameOrAlias || !in_array($commandName, $commands);
-            });
+            }));
         }
 
         $exact = in_array($name, $commands, true);
@@ -598,6 +613,9 @@ public function find($name)
                 $maxLen = max(Helper::strlen($abbrev), $maxLen);
             }
             $abbrevs = array_map(function ($cmd) use ($commandList, $usableWidth, $maxLen) {
+                if (!$commandList[$cmd] instanceof Command) {
+                    return $cmd;
+                }
                 $abbrev = str_pad($cmd, $maxLen, ' ').' '.$commandList[$cmd]->getDescription();
 
                 return Helper::strlen($abbrev) > $usableWidth ? Helper::substr($abbrev, 0, $usableWidth - 3).'...' : $abbrev;
@@ -622,7 +640,18 @@ public function find($name)
     public function all($namespace = null)
     {
         if (null === $namespace) {
-            return $this->commands;
+            if (!$this->commandLoader) {
+                return $this->commands;
+            }
+
+            $commands = $this->commands;
+            foreach ($this->commandLoader->getNames() as $name) {
+                if (!isset($commands[$name])) {
+                    $commands[$name] = $this->commandLoader->get($name);
+                }
+            }
+
+            return $commands;
         }
 
         $commands = array();
@@ -632,6 +661,14 @@ public function all($namespace = null)
             }
         }
 
+        if ($this->commandLoader) {
+            foreach ($this->commandLoader->getNames() as $name) {
+                if (!isset($commands[$name]) && $namespace === $this->extractNamespace($name, substr_count($namespace, ':') + 1)) {
+                    $commands[$name] = $this->commandLoader->get($name);
+                }
+            }
+        }
+
         return $commands;
     }
 

src/Symfony/Component/Console/CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+3.4.0
+-----
+
+ * added `CommandLoaderInterface` and PSR-11 `ContainerCommandLoader`
+
 3.3.0
 -----
 

src/Symfony/Component/Console/Command/Command.php

@@ -61,10 +61,6 @@ public function __construct($name = null)
         }
 
         $this->configure();
-
-        if (!$this->name) {
-            throw new LogicException(sprintf('The command defined in "%s" cannot have an empty name.', get_class($this)));
-        }
     }
 
     /**

src/Symfony/Component/Console/CommandLoader/CommandLoaderInterface.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace Symfony\Component\Console\CommandLoader;
+
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Exception\CommandNotFoundException;
+
+/**
+ * @author Robin Chalas <robin.chalas@gmail.com>
+ */
+interface CommandLoaderInterface
+{
+    /**
+     * Loads a command.
+     *
+     * @param string $name
+     *
+     * @return Command
+     *
+     * @throws CommandNotFoundException
+     */
+    public function get($name);
+
+    /**
+     * Checks if a command exists.
+     *
+     * @param string $name
+     *
+     * @return bool
+     */
+    public function has($name);
+
+    /**
+     * @return string[] All registered command names
+     */
+    public function getNames();
+}