django-mozilla-product-details 0.8

Product and locale details for Mozilla products.

Mozilla Product Details is a library containing information about the latest versions, localizations, etc. of Mozilla products (most notably Firefox, Firefox for mobile, and Thunderbird).

From the original README file:

This library holds information about the current builds of Firefox and
Thunderbird that Mozilla ships including:

- Latest version numbers for all builds
- English and Native names for all languages we support

This is a Django app allowing this data to be used in Django projects. A Django management command can be used as a cron job or called manually to keep the data in sync with Mozilla.

Why?

The data source of Mozilla Product Details is a PHP library kept on the Mozilla SVN server, and was originally written so it could be included into PHP projects via an SVN external. A simple svn up would fetch the latest data when it became available.

In the meantime, the Product Details library received an additional JSON feed, allowing non-PHP projects to consume the data. If, however, the consumer is not kept in SVN like the library is, there is no easy way to keep the data up to date.

For Django projects, this app solves that problem.

Getting Started

Installing

Install this library using pip:

pip install django-mozilla-product-details

… or by downloading the product_details directory and dropping it into your django project.

Add product_details to your INSTALLED_APPS to enable the management commands.

Configuration

No configuration should be necessary. However, you can add and alter the following settings to your settings.py file if you disagree with the defaults:

• PROD_DETAILS_URL defaults to the JSON directory on the Mozilla SVN server. If you have a secondary mirror at hand, or you want this tool to download completely unrelated JSON files from somewhere else, adjust this setting. Include a trailing slash.

• PROD_DETAILS_DIR is the target directory for the JSON files. It needs to be writable by the user that’ll execute the management command, and readable by the user running the Django project. Defaults to: .../install_dir_of_this_app/product_details/json/ (only for use with DBFileStorage backend (see below)).

You can further decide where the JSON data should be stored by using a storage backend class. There are 2 provided in the app currently, but it should be easy to create a subclass of product_details.storage.ProductDetailsStorage and store them wherever you like. The two provided are for the filesystem (the default) and the database. To configure which backend it uses set the following:

• PROD_DETAILS_STORAGE a string of the dotted path to a storage class (like in MIDDLEWARE_CLASSES). Available classes included with the app are product_details.storage.PDFileStorage (default) and product_details.storage.PDDatabaseStorage. To use the database storage class you should run migrations (./manage.py migrate) which will create the database table required to store the data.

This app uses Django’s cache framework to store the product data so that the data can be updated on the site without requiring a server restart. The following settings will allow you to control how this works.

• PROD_DETAILS_CACHE_NAME defaults to the cache in your CACHES setting called default (django provides an in-memory cache here by default). If you provide a name of a cache configured in the Django configuration CACHES, it will use that cache to store the file data instead.

• PROD_DETAILS_CACHE_TIMEOUT If set to an integer, it represents the number of seconds the cached data should be kept per file. Defaults to 12 hours.

Updating the feed

To update the data, execute this:

./manage.py update_product_details

You want to run this once manually after installing the app. To periodically pull in new data, you can make this a cron job.

Note: Please be considerate of the server when adding a cron job. The data does not change often enough to warrant an update every minute or so. Most applications will run perfectly fine if you pull new data once a day or even less frequently. When in doubt, contact the author of this library.

Using the data

To use the data, just import the library:

from product_details import product_details

The library turns all imported JSON files automatically into Python objects. The contents are perhaps best inspected using IPython.

Version Compare

Product details comes with an implementation of version comparison code for Mozilla-style product versions. Use it like this:

>>> from product_details.version_compare import Version
>>> v1 = Version('4.0b10')
>>> v2 = Version('4.0b10pre')
>>> v1 < v2
False

The second useful part of the version compare code is generating a list of unique versions, sorted by their release date, like this:

>>> from product_details import product_details
>>> from product_details.version_compare import version_list
>>> version_list(product_details.firefox_history_development_releases)
['3.6.4', '3.6.3', '3.6', '3.6b5', '3.6b4', '3.6b3', '3.6b2', ... ]

Caveats / Known Issues

1. While the management task will not overwrite existing files if the server returns bogus data (i.e., an empty document or unparseable JSON data), this library will also never delete a JSON file that was completely removed from the server. This is unlikely to happen very often, though.

2. You don’t want to import product_details in settings.py as that would cause an import loop (since product_details itself imports django.conf.settings). However, if you must, you can lazily wrap the import like this, mitigating the problem:

   from django.utils.functional import lazy
   
   MY_LANGUAGES = ('en-US', 'de')
   class LazyLangs(list):
       def __new__(self):
           from product_details import product_details
           return [(lang.lower(), product_details.languages[lang]['native'])
                   for lang in MY_LANGUAGES]
   LANGUAGES = lazy(LazyLangs, list)()

Development

Patches are welcome.

To run tests, install tox and run tox from the project root. This will run the tests in Python 2.6 and 2.7. If you don’t have both of those available, install nose and Mock and run the tests in your current Python version by running nosetests.

Change Log

0.8 - 2015-09-30

• Add configurable json data file storage backends.

• Add filesystem and database backends.

0.7.1 - 2015-06-15

• Do not cache a file miss.

• Catch an attempt to parse a non-JSON or corrupt file.

0.7 - 2015-05-22

• Use the Django cache framework to store product data, allowing data to be updated without a server restart.

• Add and update tests, setup tox for testing across Python and Django versions, and setup Travis for CI.

0.6 - 2015-05-08

• Initial PyPI release. Prior to this it was released and installed via github.