docs: add missing serialization yaml documentation

Author: johnkrovitch

core/serialization.md

@@ -162,6 +162,8 @@ level ignored.
 
 In the following example we use different serialization groups for the `GET` and `PUT` operations:
 
+[codeSelector]
+
 ```php
 <?php
 // api/src/Entity/Book.php
@@ -196,6 +198,32 @@ class Book
 }
 ```
 
+```yaml
+# config/api/resources/Book.yaml
+App\Entity\Book:
+    attributes:
+        normalization_context:
+            groups: ['get']
+    itemOperations:
+        get: ~
+        put:
+            normalization_context:
+                groups: ['put']
+    properties:
+        name:
+            groups: ['get', 'put']
+
+# config/serializer/Book.yaml
+App\Entity\Book:
+    attributes:
+        name:
+            groups: ['get', 'put']
+        author:
+            groups: ['get']        
+```
+
+[/codeSelector]
+
 The `name` and `author` properties will be included in the document generated during a `GET` operation because the configuration
 defined at the resource level is inherited. However the document generated when a `PUT` request will be received will only
 include the `name` property because of the specific configuration for this operation.
@@ -229,6 +257,8 @@ It is possible to embed related objects (in their entirety, or only some of thei
 response through the use of serialization groups. By using the following serialization groups annotations (`@Groups`),
 a JSON representation of the author is embedded in the book response:
 
+[codeSelector]
+
 ```php
 <?php
 // api/src/Entity/Book.php
@@ -277,6 +307,28 @@ class Person
 }
 ```
 
+```yaml
+# config/api/resources/Book.yaml
+App\Entity\Book:
+    attributes:
+        normalization_context:
+            groups: ['book']
+# config/serializer/Book.yaml
+App\Entity\Book:
+    attributes:
+        name:
+            groups: ['book']
+        author:
+            groups: ['book']
+# config/serializer/Person.yaml
+App\Entity\Person:
+    attributes:
+        name:
+            groups: ['book']
+```
+
+[/codeSelector]
+
 The generated JSON using previous settings is below:
 
 ```json
@@ -304,6 +356,8 @@ Instead of embedding relations in the main HTTP response, you may want [to "push
 It is also possible to embed a relation in `PUT` and `POST` requests. To enable that feature, set the serialization groups
 the same way as normalization. For example:
 
+[codeSelector]
+
 ```php
 <?php
 // api/src/Entity/Book.php
@@ -319,6 +373,16 @@ class Book
 }
 ```
 
+```yaml
+# config/api/resources/Book.yaml
+App\Entity\Book:
+    attributes:
+        denormalization_context:
+            groups: ['book']
+```
+
+[/codeSelector]
+
 The following rules apply when denormalizing embedded relations:
 
 * If an `@id` key is present in the embedded resource, then the object corresponding to the given URI will be retrieved through
@@ -331,6 +395,8 @@ You can specify as many embedded relation levels as you want.
 
 It is a common problem to have entities that reference other entities of the same type:
 
+[codeSelector]
+
 ```php
 <?php
 // api/src/Entity/Person.php
@@ -364,13 +430,34 @@ class Person
  
     // ...
 }
+```
+
+```yaml
+# config/api/resources/Person.yaml
+App\Entity\Person:
+    attributes:
+        normalization_context:
+            groups: ['person']
+        denormalization_context:
+            groups: ['person']
 
+# config/serializer/Person.yaml
+App\Entity\Person:
+    attributes:
+        name:
+            groups: ['person']
+        parent:
+            groups: ['person']
 ```
 
+[/codeSelector]
+
 The problem here is that the **$parent** property become automatically an embedded object. Besides, the property won't be shown on the OpenAPI view.
 
 To force the **$parent** property to be used as an IRI, add an **#[ApiProperty(readableLink: false, writableLink: false)]** annotation:
 
+[codeSelector]
+
 ```php
 <?php
 // api/src/Entity/Person.php
@@ -408,10 +495,36 @@ class Person
 
 ```
 
+```yaml
+# config/api/resources/Person.yaml
+App\Entity\Person:
+    attributes:
+        normalization_context:
+            groups: ['person']
+        denormalization_context:
+            groups: ['person']
+    properties:
+        parent:
+            readableLink: false
+            writableLink: false
+
+# config/serializer/Person.yaml
+App\Entity\Person:
+    attributes:
+        name:
+            groups: ['person']
+        parent:
+            groups: ['person']
+```
+
+[/codeSelector]
+
 ## Calculated Field
 
 Sometimes you need to expose calculated fields. This can be done by leveraging the groups. This time not on a property, but on a method.
 
+[codeSelector]
+
 ```php
 <?php
 
@@ -470,12 +583,33 @@ class Greeting
 }
 ```
 
+```yaml
+# config/api/resources/Greeting.yaml
+App\Entity\Greeting:
+    collectionOperations:
+        get:
+            normalization_context:
+                groups: 'greeting:collection:get'
+
+# config/serializer/Greeting.yaml
+App\Entity\Greeting:
+    attributes:
+        id:
+            groups: 'greeting:collection:get'
+        getSum:
+            groups: 'greeting:collection:get'
+```
+
+[/codeSelector]
+
 ## Changing the Serialization Context Dynamically
 
 <p align="center" class="symfonycasts"><a href="https://symfonycasts.com/screencast/api-platform-security/service-decoration?cid=apip"><img src="../distribution/images/symfonycasts-player.png" alt="Context Builder & Service Decoration screencast"><br>Watch the Context Builder & Service Decoration screencast</a></p>
 
 Let's imagine a resource where most fields can be managed by any user, but some can be managed only by admin users:
 
+[codeSelector]
+
 ```php
 <?php
 // api/src/Entity/Book.php
@@ -515,6 +649,26 @@ class Book
 }
 ```
 
+```yaml
+# config/api/resources/Book.yaml
+App\Entity\Book: 
+    attributes:
+        normalization_context:
+            groups: ['book:output']
+        denormalization_context:
+            groups: ['book:input']
+
+# config/serializer/Book.yaml
+App\Entity\Book:
+    attributes:
+        active:
+            groups: ['book:output', 'admin:input']
+        name:
+            groups: ['book:output', 'book:input']
+```
+
+[/codeSelector]
+
 All entry points are the same for all users, so we should find a way to detect if the authenticated user is an admin, and if so
 dynamically add the `admin:input` value to deserialization groups in the `$context` array.
 
@@ -830,6 +984,8 @@ an IRI. A client that uses JSON-LD must send a second HTTP request to retrieve i
 You can configure API Platform to embed the JSON-LD context in the root document by adding the `jsonld_embed_context`
 attribute to the `#[ApiResource]` annotation:
 
+[codeSelector]
+
 ```php
 <?php
 // api/src/Entity/Book.php
@@ -845,6 +1001,16 @@ class Book
 }
 ```
 
+```yaml
+# config/api/resources/Book.yaml
+App\Entity\Book:
+    attributes:
+        normalization_context:
+            jsonld_embed_context: true
+```
+
+[/codeSelector]
+
 The JSON output will now include the embedded context:
 
 ```json