feature #12917 [Console] Updated section 'Building a single Command Application' with the new 'SingleCommandApplication' (lyrixx)

This PR was merged into the master branch.

Discussion
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[Console] Updated section 'Building a single Command Application' with the new 'SingleCommandApplication'

fixes #12903

Commits
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70d523c [Console] Updated section 'Building a single Command Application' with the new 'SingleCommandApplication'

Author: OskarStark

components/console/single_command_tool.rst

@@ -5,34 +5,36 @@ Building a single Command Application
 =====================================
 
 When building a command line tool, you may not need to provide several commands.
-In such case, having to pass the command name each time is tedious. Fortunately,
-it is possible to remove this need by declaring a single command application::
+In such case, having to pass the command name each time is tedious.
+
+.. versionadded:: 5.1
+
+    The class :class:`Symfony\\Component\\Console\\SingleCommandApplication` was
+    introduced in Symfony 5.1.
+
+Fortunately, it is possible to remove this need by declaring a single command
+application::
 
     #!/usr/bin/env php
     <?php
     require __DIR__.'/vendor/autoload.php';
 
-    use Symfony\Component\Console\Application;
     use Symfony\Component\Console\Input\InputArgument;
     use Symfony\Component\Console\Input\InputInterface;
     use Symfony\Component\Console\Input\InputOption;
     use Symfony\Component\Console\Output\OutputInterface;
-
-    (new Application('echo', '1.0.0'))
-        ->register('echo')
-            ->addArgument('foo', InputArgument::OPTIONAL, 'The directory')
-            ->addOption('bar', null, InputOption::VALUE_REQUIRED)
-            ->setCode(function(InputInterface $input, OutputInterface $output) {
-                // output arguments and options
-            })
-        ->getApplication()
-        ->setDefaultCommand('echo', true) // Single command application
+    use Symfony\Component\Console\SingleCommandApplication;
+
+    (new SingleCommandApplication())
+        ->setName('My Super Command') // Optional
+        ->setVersion('1.0.0') // Optional
+        ->addArgument('foo', InputArgument::OPTIONAL, 'The directory')
+        ->addOption('bar', null, InputOption::VALUE_REQUIRED)
+        ->setCode(function (InputInterface $input, OutputInterface $output) {
+            // output arguments and options
+        })
         ->run();
 
-The method :method:`Symfony\\Component\\Console\\Application::setDefaultCommand`
-accepts a boolean as second parameter. If true, the command ``echo`` will then
-always be used, without having to pass its name.
-
 You can still register a command as usual::
 
     #!/usr/bin/env php
@@ -49,3 +51,7 @@ You can still register a command as usual::
 
     $application->setDefaultCommand($command->getName(), true);
     $application->run();
+
+The method :method:`Symfony\\Component\\Console\\Application::setDefaultCommand`
+accepts a boolean as second parameter. If true, the command ``echo`` will then
+always be used, without having to pass its name.