Merge branch '3.4' into 4.4

* 3.4:
  Shortening the lenghty Xdebug explanation
  Shortening the text

Author: javiereguiluz

form/form_collections.rst

@@ -104,12 +104,10 @@ Then, create a form class so that a ``Tag`` object can be modified by the user::
         }
     }
 
-With this, you have enough to render a tag form by itself. But since the end
-goal is to allow the tags of a ``Task`` to be modified right inside the task
-form itself, create a form for the ``Task`` class.
-
-Notice that you embed a collection of ``TagType`` forms using the
-:doc:`CollectionType </reference/forms/types/collection>` field::
+Next, let's create a form for the ``Task`` entity, using a
+:doc:`CollectionType </reference/forms/types/collection>` field of ``TagType``
+forms. This will allow us to modify all the ``Tag`` elements of a ``Task`` right
+inside the task form itself::
 
     // src/Form/TaskType.php
     namespace App\Form;
@@ -203,32 +201,20 @@ to render them:
 
     {# ... #}
 
-When the user submits the form, the submitted data for the ``tags`` field are
-used to construct an ``ArrayCollection`` of ``Tag`` objects, which is then set
-on the ``tag`` field of the ``Task`` instance.
-
-The ``tags`` collection is accessible naturally via ``$task->getTags()``
-and can be persisted to the database or used however you need.
+When the user submits the form, the submitted data for the ``tags`` field is
+used to construct an ``ArrayCollection`` of ``Tag`` objects. The collection is
+then set on the ``tag`` field of the ``Task`` and can be accessed via ``$task->getTags()``.
 
-So far, this works great, but this doesn't allow you to dynamically add new
-tags or delete existing tags. So, while editing existing tags will work
-great, your user can't actually add any new tags yet.
+So far, this works great, but only to edit *existing* tags. It doesn't allow us
+yet to add new tags or delete existing ones.
 
 .. caution::
 
-    In this article, you embed only one collection, but you are not limited
-    to this. You can also embed nested collection as many levels down as you
-    like. But if you use Xdebug in your development setup, you may receive
-    a ``Maximum function nesting level of '100' reached, aborting!`` error.
-    This is due to the ``xdebug.max_nesting_level`` PHP setting, which defaults
-    to ``100``.
-
-    This directive limits recursion to 100 calls which may not be enough for
-    rendering the form in the template if you render the whole form at
-    once (e.g ``form_widget(form)``). To fix this you can set this directive
-    to a higher value (either via a ``php.ini`` file or via :phpfunction:`ini_set`,
-    for example in ``public/index.php``) or render each form field by hand
-    using ``form_row()``.
+    You can embed nested collections as many levels down as you like. However,
+    if you use Xdebug, you may receive a ``Maximum function nesting level of '100'
+    reached, aborting!`` error. To fix this, increase the ``xdebug.max_nesting_level``
+    PHP setting, or render each form field by hand using ``form_row()`` instead of
+    rendering the whole form at once (e.g ``form_widget(form)``).
 
 .. _form-collections-new-prototype: