graceful 0.0.3

graceful

graceful is documentation centered falcon REST toolkit. It is highly inspired by Django REST framework - mostly by how object serialization is done but more emphasis here is put on API to being self-descriptive.

Features:

• generic classes for list and single object resources

• simple but extendable pagination

• structured responses with content/meta separation

• declarative fields and parameters

• self-descriptive-everything: API description accessible both in python and through OPTIONS requests

• painless validation

• 100% tests coverage

• falcon>=0.3.0

• python3 exclusive (tested from 3.3 to 3.4)

python3 only

Important: graceful is python3 exclusive because right now should be a good time to forget about python2. There are no plans for making graceful python2 compatibile although it would be pretty straightforward do do so with existing tools (like six).

usage

Here will be presented very simple example of working API made with graceful. For extended tutorial and more information please refer to documentation.

import falcon

from graceful.serializers import BaseSerializer
from graceful.fields import IntField, RawField
from graceful.parameters import StringParam
from graceful.resources.generic import (
    RetrieveAPI,
    PaginatedListAPI,
)

api = application = falcon.API()

# lets pretend that this is our backend storage
CATS_STORAGE = [
    {"id": 0, "name": "kitty", "breed": "saimese"},
    {"id": 1, "name": "lucie", "breed": "maine coon"},
    {"id": 2, "name": "molly", "breed": "sphynx"},
]


# this is how we represent cats in our API
class CatSerializer(BaseSerializer):
    id = IntField("cat identification number", read_only=True)
    name = RawField("cat name")
    breed = RawField("official breed name")


class Cat(RetrieveAPI):
    """
    Single cat identified by its id
    """
    serializer = CatSerializer()

    def get_cat(self, cat_id):
        try:
            return [
                cat for cat in CATS_STORAGE if cat['id'] == int(cat_id)
            ][0]
        except IndexError:
            raise falcon.HTTPNotFound


    def retrieve(self, params, meta, **kwargs):
        cat_id = kwargs['cat_id']
        return self.get_cat(cat_id)

class CatList(PaginatedListAPI):
    """
    List of all cats in our API
    """
    serializer = CatSerializer()

    breed = StringParam("set this param to filter cats by breed")

    def list(self, params, meta, **kwargs):
        if 'breed' in params:
            filtered = [
                cat for cat in CATS_STORAGE
                if cat['breed'] == params['breed']
            ]
            return filtered
        else:
            return CATS_STORAGE

api.add_route("/v1/cats/{cat_id}", Cat())
api.add_route("/v1/cats/", CatList())

Now you’re ready to query it (here with awesome hhtpie tool):

$ http localhost:8888/v0/cats/?breed=saimese
HTTP/1.1 200 OK
Connection: close
Date: Tue, 16 Jun 2015 08:43:05 GMT
Server: gunicorn/19.3.0
content-length: 116
content-type: application/json

{
    "content": [
        {
            "breed": "saimese",
            "id": 0,
            "name": "kitty"
        }
    ],
    "meta": {
        "params": {
            "breed": "saimese",
            "indent": 0
        }
    }
}

Or access API description issuing OPTIONS request:

$ http OPTIONS localhost:8888/v0/cats
HTTP/1.1 200 OK
Connection: close
Date: Tue, 16 Jun 2015 08:40:00 GMT
Server: gunicorn/19.3.0
content-length: 740
content-type: application/json

{
    "details": "List of all cats in our API",
    "fields": {
        "breed": {
            "details": "official breed name",
            "label": null,
            "spec": null,
            "type": "string"
        },
        "id": {
            "details": "cat identification number",
            "label": null,
            "spec": null,
            "type": "int"
        },
        "name": {
            "details": "cat name",
            "label": null,
            "spec": null,
            "type": "string"
        }
    },
    "methods": [
        "GET",
        "OPTIONS"
    ],
    "name": "CatList",
    "params": {
        "breed": {
            "default": null,
            "details": "set this param to filter cats by breed",
            "label": null,
            "required": false,
            "spec": null,
            "type": "string"
        },
        "indent": {
            "default": "0",
            "details": "JSON output indentation. Set to 0 if output should not be formated.",
            "label": null,
            "required": false,
            "spec": null,
            "type": "integer"
        }
    },
    "path": "/v0/cats",
    "type": "list"
}

contributing

Any contribution is welcome. Issues, suggestions, pull requests - whatever. There is only short set of rules that guide this project development you should be aware of before submitting a pull request:

• only requests that have passing CI builds (Travis) will be merged

• code is checked with flakes8 during build so this implicitely means that PEP-8 is a must

• no changes that decrease coverage will be merged

One thing: if you submit a PR please do not rebase it later unless you are asked for that explicitely. Reviewing pull requests that suddenly had their history rewritten just drives me crazy.

licence

See LICENSE file