How to implement custom renderers in Flask

5289679973777408### Renderers In web development, Renderers take response values from views and transform them into a string or bytestring value to be used as a response body.

Custom renderers in Flask

Flask allows the implementation of custom, non-built-in renderers. To do so, the BaseRenderer needs to be overridden. Next, the media_type member of this class and the render(self, data, media_type, **options) method needs to be defined. The following example shows a custom renderer that returns YAML.

# BaseRenderer class
class YAMLRenderer(renderers.BaseRenderer):
  # media_type defined
  media_type = 'application/yaml'
    
  #render method defined 
  def render(self, data, media_type, **options):
    return yaml.dump(data, encoding=self.charset)

Here, the data argument is the request data that is returned by the view. The media_type argument is an optional parameter that, if provided, is the accepted media type. **options are some additional arguments that may be needed to carry out rendering. By default, the following options are included:

  • status is a string that represents the response status.
  • status_code is an integer that represents the response status code.
  • headers is a dictionary that contains the response headers.

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