Creating a custom MetaData adapter

When creating a custom adapter, the first thing you'll want to do is import the base class and tools you will need:

from drf_auto_endpoint.adapters import BaseAdapter, MetaDataInfo, PROPERTY, GETTER

By default, the BaseAdapter produces a result containing only fields. If you'd like to get more information like actions or languages, you'll have to override the metadata_info property of the adapter. metadata_info is a list of MetaDataInfo objects. A MetaDataInfo object takes 3 arguments:

• the name of the property or method (as in get_<name>()) to call on the endpoint
• whether the name refers to a PROPERTY or a GETTER
• a default value (used to produce metadata on non-model endpoints or viewsets)

Here is a list of existing properties and getters that can be used:

• 'fields', GETTER, []
• 'fieldsets', GETTER, []
• 'list_display', GETTER, []
• 'filter_fields', GETTER, []
• 'languages', GETTER, []
• 'ordering_fields', GETTER, []
• 'needs', GETTER, []
• 'list_editable', GETTER, []
• 'sortable_by', GETTER, []
• 'translated_fields', GETTER, []
• 'custom_actions', GETTER, []
• 'bulk_actions', GETTER, []
• 'save_twice', PROPERTY, False
• 'search_enabled', PROPERTY, False

If you need more information, feel free to add properties and getters on your custom Endpoint.

Finally, if the output format of the default adapter doesn't suite you, you will probably want to override the adapt_field, render_root or render method on your custom adapter.

adapt_field

adapt_field is a class method that receives a "field-type" dictionary and output a "field-type" dictionary. adapt_field is called on each field by BaseAdapter.render.

Example custom implementation:

from drf_auto_endpoint.adapters import BaseAdapter


class MyAdapter(BaseAdapter)
    @classmethod
    def adapt_field(cls, field):
        ui = field.pop('ui')
        field['display_name'] = ui['label']
        return field

The render method receives a raw dictionary as input and is expected to return a raw dictionary as output.

render

render is the method used to adapt the default metadata output to your frontend's needs. BaseAdapter.render only return the contend of 'fields' so you will have to override it if you want to get metadata_info other than 'fields'.

Example custom implementation:

from drf_auto_endpoint.adapters import BaseAdapter


class MyAdapter(BaseAdapter)
    def render(self, config):
        config['fields'] = super(MyAdapter, self).render(config)
        return config

render_root

render_root is similar to render but is only used to render metadata for the API root

Example custom implementation:

from drf_auto_endpoint.adapters import BaseAdapter


class MyAdapter(BaseAdapter)
    def render_root(self, config):
        config = super(MyAdapter, self).render(config)
        config['bogus'] = 'adapted'
        return config

Full sample custom Endpoint and Adapter

from random import randint

from django.utils import timezone

from drf_auto_endpoint.endpoints import Endpoint
from drf_auto_endpoint.adapters import BaseAdapter, MetaDataInfo, PROPERTY, GETTER


class CustomEndpoint(Endpoint):

    @property
    def silly_prop(self):
        return 'silly'

    def get_random_array(self):
        rv = []
        for i in range(randint(1, 10)):
            rv.append(randint(1, 100))
        return rv


class CustomAdapter(BaseAdapter):

    metadata_info = [
          MetaDataInfo('fields', GETTER, []),
          MetaDataInfo('list_display', GETTER, []),
          MetaDataInfo('filter_fields', GETTER, []),
          MetaDataInfo('search_enabled', PROPERTY, False),
          MetaDataInfo('silly_prop', PROPERTY, 'Not so silly after all'),
          MetaDataInfo('random_array', GETTER, []),
    ]

    @classmethod
    def adapt_field(cls, field):
        ui = field.pop('ui')
        field['display_name'] = ui['label']
        return field

    def render(self, config):
        config['fields'] = super(MyAdapter, self).render(config)
        config['silly_property'] = config.pop('silly_prop')
        return config

    def render_root(self, config):
        config = super(MyAdapter, self).render(config)
        config['rendered_at'] = timezone.now().strftime('%Y-%M-%d %H:%m:%S')
        return config