Expose SQLAlchemy model instances and paginated querysets as hal+json resources. Warning: Not a silver bullet for creating API’s. This is only meant to quickly expose a db.Model and views to validate incoming data. Generally speaking you should aim to expose processes not just map CRUD SQL operations to the HTTP verbs. That being said, I believe this is a common enough scenario to automate.

I have made an effort not to tie it too deeply into SQLAlchemy so it would be easy to adopt other database storages. The biggest blocker is the Flask-SQLAlchemy pagination class.

Three Flask class based views are provided:

• ResourceView: A hal+json resource for Model instances
• IndexView: A paginated hal+json resource for Model querysets
• FormView: Validates incoming JSON data, reports errors nicely (POSTs to indexes and PATCHes resources)

The following assumptions are made:

• get_query returns a result set for IndexView and a SQLAlchemy Query instance for ResourceView.
• Models have a json attribute that exposes publically available fields and their values. This is what what your API consumer sees.

The GET method is already implemented for ResourceView and IndexView resources.

See example.py for ... an example.

See the Internet Draft

Paginated Hypermedia API Language (HAL) response example:

HTTP/1.0 200 OK
Content-Type: application/hal+json
Content-Length: 283
Server: Werkzeug/0.8.3 Python/2.7.2
Date: Thu, 12 Jul 2012 18:26:33 GMT
{
  "_embedded": {
    "workouts": [
      {
        "_links": {
          "self": {
            "href": "/workouts/1"
          }
        }
        "id": 1,
        "score": "1",
      },
      {
        "_links": {
          "self": {
            "href": "/workouts/2"
          }
        }
        "id": 2,
        "score": "1",
      }
    ]
  },
  "_links": {
    "self": {
      "href": "/workouts"
    },
    "last": {
      "href": "/workouts?page=3"
    },
    "next": {
      "href": "/workouts?page=2"
    }
  }
}