minor #18813 [DependencyInjection] Add a note about constructor promotion and IDEs errors about attributes (javiereguiluz)

This PR was merged into the 5.4 branch.

Discussion
----------

[DependencyInjection] Add a note about constructor promotion and IDEs errors about attributes

Fixes #18071.

I propose to include the full error message shown by the IDE so it's easier to find this when googling about the error.

Commits
-------

0121f23 Add a note about constructor promotion and IDEs errors about attributes

Author: javiereguiluz

service_container/autowiring.rst

@@ -582,6 +582,13 @@ attribute like this::
         }
     }
 
+.. note::
+
+    Some IDEs will show an error when using the ``#[Target]`` as in the previous example:
+    *"Attribute cannot be applied to a property because it does not contain the 'Attribute::TARGET_PROPERTY' flag"*.
+    The reason is that thanks to `PHP constructor promotion`_ this constructor
+    argument is both a parameter and a class property. You can safely ignore this error message.
+
 .. versionadded:: 5.3
 
     The ``#[Target]`` attribute was introduced in Symfony 5.3.
@@ -737,3 +744,4 @@ over all code.
 
 .. _ROT13: https://en.wikipedia.org/wiki/ROT13
 .. _service definition prototype: https://symfony.com/blog/new-in-symfony-3-3-psr-4-based-service-discovery
+.. _`PHP constructor promotion`: https://www.php.net/manual/en/language.oop5.decon.php#language.oop5.decon.constructor.promotion

service_container/tags.rst

@@ -717,6 +717,14 @@ directly via PHP attributes:
             ;
         };
 
+.. note::
+
+    Some IDEs will show an error when using the ``#[TaggedIterator]`` together
+    with the `PHP constructor promotion`_:
+    *"Attribute cannot be applied to a property because it does not contain the 'Attribute::TARGET_PROPERTY' flag"*.
+    The reason is that those constructor arguments are both parameters and class
+    properties. You can safely ignore this error message.
+
 .. versionadded:: 5.3
 
     The ``#[TaggedIterator]`` attribute was introduced in Symfony 5.3 and requires PHP 8.
@@ -1092,3 +1100,5 @@ be used directly on the class of the service you want to configure::
 .. versionadded:: 5.3
 
     The ``#[AsTaggedItem]`` attribute was introduced in Symfony 5.3.
+
+.. _`PHP constructor promotion`: https://www.php.net/manual/en/language.oop5.decon.php#language.oop5.decon.constructor.promotion