Skip to main content
This is a pre-production deployment of Warehouse. Changes made here affect the production instance of PyPI (pypi.python.org).
Help us improve Python packaging - Donate today!

HAL JSON parser and generator

Project Description

Dougrain is a Python library to help you work with the JSON variant of the Hypertext Application Language (HAL). It uses Python objects to represent the JSON document, so you can use it with whichever JSON library you prefer.

Status

This is a pre-release version. It usually works pretty well, but the API may have breaking changes in minor releases until version 1.0. The HAL specification is still being developed, so Dougrain is unlikely to have a stable API until HAL itself is stable.

Compatibility

JSON HAL drafts 3, 4, and 5. Python 2.7, 3.2, and 3.3.

This version conforms to JSON Hypermedia API Language Internet Draft 5, but it can also work with JSON from Draft 4 and Draft 3. The draft version can be explicitly selected when the document is constructed, but the default behavior is for documents to automatically detect which draft to use.

This version is tested on Python 2.7, including PyPy, Python 3.2, and Python 3.3.

Installation

You’ll probably need to use sudo on the install commands, or run in a virtualenv.

The easiest way to install the current release is to use pip:

$ pip install dougrain

You can install a local copy of the source in the usual way:

$ cd dougrain
$ pip install -r requirements.txt
$ python setup.py install

Example

Document.from_object loads HAL data from a dict:

>>> from dougrain import Document
>>> doc = Document.from_object(
...     {
...         "_embedded": {
...             "r:post": {
...                 "_links": {
...                     "self": {
...                         "href": "/1"
...                     },
...                     "r:site": {
...                         "href": "/"
...                     }
...                 },
...                 "name": "First child"
...             }
...         },
...         "welcome": "Hi there!",
...         "_links": {
...             "curies": [
...                 {
...                     "href": "http://localhost/rels/{rel}",
...                     "name": "r",
...                     "templated": True
...                 }
...             ],
...             "self": {
...                 "href": "/"
...             },
...             "r:post": {
...                 "href": "/1"
...             },
...             "r:tags": {
...                 "href": "/tags"
...             }
...         }
...     },
...     base_uri="http://localhost/")

Document instances provide methods to interrogate the document’s properties, links, and embedded resources.

>>> doc.properties['welcome']
'Hi there!'
>>> doc.links['r:tags'].url()
'http://localhost/tags'
>>> doc.embedded['r:post'].url()
'http://localhost/1'

Link relations can be specified using CURIEs or URI references:

>>> doc.links['r:tags'].url()
'http://localhost/tags'
>>> doc.links['/rels/tags'].url()
'http://localhost/tags'

Builder provides a lightweight API for building HAL resources from scratch. Many of Builder’s methods can be chained:

>>> from dougrain import Builder
>>> new_post = (Builder("/2").set_property('name', "Second Child")
...                          .add_curie('admin', "/adminrels/{rel}")
...                          .add_link('admin:privacy', "/2/privacy"))
>>> import json
>>> print(json.dumps(new_post.as_object(), indent=2))
{
  "_links": {
    "curies": [
      {
        "href": "/adminrels/{rel}",
        "name": "admin",
        "templated": true
      }
    ],
    "self": {
      "href": "/2"
    },
    "admin:privacy": {
      "href": "/2/privacy"
    }
  },
  "name": "Second Child"
}

Builder and Document can be used together. For example, Document.embed will accept a Builder instance:

>>> doc.embed('r:post', new_post)
>>> [post.properties['name'] for post in doc.embedded['/rels/post']]
['First child', 'Second child']
Release History

Release History

This version
History Node

0.5.1

History Node

0.5

History Node

0.4

History Node

0.3

History Node

0.2

History Node

0.1

Download Files

Download Files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

File Name & Checksum SHA256 Checksum Help Version File Type Upload Date
dougrain-0.5.1.tar.gz (23.7 kB) Copy SHA256 Checksum SHA256 Source Aug 29, 2013

Supported By

WebFaction WebFaction Technical Writing Elastic Elastic Search Pingdom Pingdom Monitoring Dyn Dyn DNS Sentry Sentry Error Logging CloudAMQP CloudAMQP RabbitMQ Heroku Heroku PaaS Kabu Creative Kabu Creative UX & Design Fastly Fastly CDN DigiCert DigiCert EV Certificate Rackspace Rackspace Cloud Servers DreamHost DreamHost Log Hosting