feature #3426 New Feature: Change the Default Command in the Console component (danielcsgomes)

This PR was merged into the master branch.

Discussion
----------

New Feature: Change the Default Command in the Console component

| Q             | A
| ------------- | ---
| Doc fix?      | no
| New docs?     | yes (symfony/symfony#9776)
| Applies to    | 2.5+
| Fixed tickets |

I followed the suggestion from @wouterj in IRC on changing the `single_command_tool` and added the documentation for the new feature there.

Commits
-------

c1b2aad Applied suggestions from Ryan
5e97202 Applyed suggestions from @fabpot and @stof
c23f34e Applied some suggestions
012456d Moved `versionadded` to the right section
730985f Updated references to the new document
af9eac4 Changed the code to remove references to Symfony Framework since it's the standalone component
60e2b3e Added the delete document to avoid broken urls and added a notice that the document was moved to another location
11c7174 Added the version number where the setDefaultCommand was introduced
b29ab89 Documented the Change the Default Command in the Console component

Author: weaverryan

components/console/changing_default_command.rst

@@ -0,0 +1,67 @@
+.. index::
+    single: Console; Changing the Default Command
+
+Changing the Default Command
+============================
+
+.. versionadded:: 2.5,
+    The :method:`Symfony\\Component\\Console\\Application::setDefaultCommand`
+    method was introduced in version 2.5.
+
+will always run the ``ListCommand`` when no command name is passed. In order to change
+the default command you just need to pass the command name you want to run by
+default to the ``setDefaultCommand`` method::
+
+    namespace Acme\Command;
+
+    use Symfony\Component\Console\Command\Command;
+    use Symfony\Component\Console\Input\InputInterface;
+    use Symfony\Component\Console\Output\OutputInterface;
+
+    class HelloWorldCommand extends Command
+    {
+        protected function configure()
+        {
+            $this->setName('hello:world')
+                ->setDescription('Outputs \'Hello World\'');
+        }
+
+        protected function execute(InputInterface $input, OutputInterface $output)
+        {
+            $output->writeln('Hello World');
+        }
+    }
+
+Executing the application and changing the default Command::
+
+    // application.php
+
+    use Acme\Command\HelloWorldCommand;
+    use Symfony\Component\Console\Application;
+
+    $command = new HelloWorldCommand();
+    $application = new Application();
+    $application->add($command);
+    $application->setDefaultCommand($command->getName());
+    $application->run();
+
+Test the new default console command by running the following:
+
+.. code-block:: bash
+
+    $ php application.php
+
+This will print the following to the command line:
+
+.. code-block:: text
+
+    Hello Fabien
+
+.. tip::
+
+    This feature has a limitation: you cannot use it with any Command arguments.
+
+Learn More!
+-----------
+
+* :doc:`/components/console/single_command_tool`

components/console/index.rst

@@ -6,6 +6,7 @@ Console
 
     introduction
     usage
+    changing_default_command
     single_command_tool
     events
     helpers/index

components/console/introduction.rst

@@ -526,6 +526,7 @@ Learn More!
 
 * :doc:`/components/console/usage`
 * :doc:`/components/console/single_command_tool`
+* :doc:`/components/console/changing_default_command`
 
 .. _Packagist: https://packagist.org/packages/symfony/console
 .. _ANSICON: https://github.com/adoxa/ansicon/downloads

components/console/single_command_tool.rst

@@ -1,5 +1,5 @@
 .. index::
-   single: Console; Single command application
+    single: Console; Single command application
 
 Building a Single Command Application
 =====================================

components/map.rst.inc

@@ -20,6 +20,7 @@
   * :doc:`/components/console/introduction`
   * :doc:`/components/console/usage`
   * :doc:`/components/console/single_command_tool`
+  * :doc:`/components/console/changing_default_command`
   * :doc:`/components/console/events`
   * :doc:`/components/console/helpers/index`