Renderers and Parsers

class JSONRenderer(renderers.JSONRenderer):
    """
    JSON:API compliant renderer with media type application/vnd.api+json.
    
    Transforms Django REST framework responses into JSON:API format with:
    - Resource objects with type, id, attributes, and relationships
    - Top-level data, meta, and links sections
    - Proper error formatting
    - Include parameter support for compound documents
    """
    
    media_type = "application/vnd.api+json"
    format = "vnd.api+json"
    
    @classmethod
    def extract_attributes(cls, fields, resource):
        """
        Extract attributes from resource data for JSON:API resource object.
        
        Args:
            fields: Serializer fields dict
            resource: Resource data dict
            
        Returns:
            dict: Attributes dict with formatted field names
        """
    
    @classmethod  
    def extract_relationships(cls, fields, resource, resource_instance):
        """
        Extract relationships from resource data for JSON:API resource object.
        
        Args:
            fields: Serializer fields dict
            resource: Resource data dict
            resource_instance: Django model instance
            
        Returns:
            dict: Relationships dict with data and links
        """
    
    def render(self, data, accepted_media_type=None, renderer_context=None):
        """
        Render data as JSON:API response.
        
        Args:
            data: Data to render
            accepted_media_type: Accepted media type
            renderer_context: Request context
            
        Returns:
            bytes: JSON:API formatted response
        """

# settings.py
REST_FRAMEWORK = {
    'DEFAULT_RENDERER_CLASSES': [
        'rest_framework_json_api.renderers.JSONRenderer',
    ],
}

# Transforms this Django REST framework response:
# {"id": 1, "title": "Article", "author": 5}

# Into this JSON:API response:
# {
#   "data": {
#     "type": "articles",
#     "id": "1",
#     "attributes": {
#       "title": "Article"
#     },
#     "relationships": {
#       "author": {
#         "data": {"type": "authors", "id": "5"}
#       }
#     }
#   }
# }

class JSONParser(parsers.JSONParser):
    """
    JSON:API compliant parser with media type application/vnd.api+json.
    
    Parses JSON:API requests and extracts:
    - Attributes from resource objects
    - Relationships as resource identifier objects
    - Meta information
    """
    
    media_type = "application/vnd.api+json"
    renderer_class = JSONRenderer
    
    @staticmethod
    def parse_attributes(data):
        """
        Parse attributes from JSON:API resource object.
        
        Args:
            data: JSON:API resource object data
            
        Returns:
            dict: Attributes with field names converted to Django format
        """
    
    @staticmethod
    def parse_relationships(data):
        """
        Parse relationships from JSON:API resource object.
        
        Args:
            data: JSON:API resource object data
            
        Returns:
            dict: Relationships as resource identifier objects
        """
    
    @staticmethod
    def parse_metadata(result):
        """
        Parse meta section from JSON:API request.
        
        Args:
            result: Full JSON:API request data
            
        Returns:
            dict: Meta information with _meta key
        """
    
    def parse_data(self, result, parser_context):
        """
        Parse JSON:API request data into Django REST framework format.
        
        Args:
            result: Parsed JSON data
            parser_context: Parser context with view information
            
        Returns:
            dict: Data in Django REST framework format
            
        Raises:
            ParseError: If request doesn't contain primary data or is malformed
        """

# settings.py
REST_FRAMEWORK = {
    'DEFAULT_PARSER_CLASSES': [
        'rest_framework_json_api.parsers.JSONParser',
    ],
}

# Parses this JSON:API request:
# {
#   "data": {
#     "type": "articles",
#     "attributes": {
#       "title": "New Article",
#       "content": "Article content"
#     },
#     "relationships": {
#       "author": {
#         "data": {"type": "authors", "id": "5"}
#       }
#     }
#   }
# }

# Into this Django REST framework format:
# {
#   "title": "New Article",
#   "content": "Article content", 
#   "author": {"type": "authors", "id": "5"}
# }

{
  "data": {
    "type": "resource-type",
    "id": "123",
    "attributes": {
      "field-name": "value"
    },
    "relationships": {
      "related-field": {
        "data": {"type": "related-type", "id": "456"}
      }
    },
    "links": {
      "self": "/api/resource-type/123"
    }
  },
  "meta": {
    "key": "value"
  }
}

{
  "data": [
    {
      "type": "resource-type",
      "id": "123",
      "attributes": {...},
      "relationships": {...}
    }
  ],
  "meta": {
    "pagination": {
      "page": 1,
      "pages": 10,
      "count": 100
    }
  },
  "links": {
    "first": "/api/resource-type?page=1",
    "next": "/api/resource-type?page=2",
    "last": "/api/resource-type?page=10"
  }
}

{
  "errors": [
    {
      "status": "400",
      "detail": "This field is required.",
      "source": {
        "pointer": "/data/attributes/title"
      }
    }
  ]
}

# settings.py
JSON_API_FORMAT_FIELD_NAMES = True

# Django field: created_at
# JSON:API attribute: "created-at"

# Parser automatically converts back:
# JSON:API "created-at" -> Django "created_at"

# Request: GET /articles/1?include=author,comments.user
# Response includes related resources in "included" section:
{
  "data": {...},
  "included": [
    {
      "type": "authors",
      "id": "5",
      "attributes": {...}
    },
    {
      "type": "comments", 
      "id": "10",
      "attributes": {...},
      "relationships": {
        "user": {"data": {"type": "users", "id": "3"}}
      }
    }
  ]
}

# POST /articles/1/relationships/author
# {
#   "data": {"type": "authors", "id": "6"}
# }

# Parser extracts relationship data for relationship views

from rest_framework_json_api.renderers import JSONRenderer
from rest_framework_json_api.parsers import JSONParser

# Base classes from Django REST framework
from rest_framework.renderers import JSONRenderer as DRFJSONRenderer
from rest_framework.parsers import JSONParser as DRFJSONParser