django-dbtemplates 0.5.0

Template loader for database stored templates

dbtemplates is a Django app that comes with to parts: It allows you to create templates that are saved in your database, and it provides a so called template loader, a function that enables Django to find the templates you created in the database.

It also includes a extensible caching mechanism and supports version control of the templates saved in the database.

Setup

1. Get the source from the subversion repository

2. Follow the instructions in the INSTALL file

3. Edit the settings.py of your Django site:

   • Add dbtemplates to the INSTALLED_APPS setting

     Check if django.contrib.sites and django.contrib.admin are in INSTALLED_APPS and add if necessary.

     It should look something like this:

     INSTALLED_APPS = (
         'django.contrib.auth',
         'django.contrib.contenttypes',
         'django.contrib.sessions',
         'django.contrib.sites',
         'django.contrib.admin',
         'django.contrib.flatpages',
         # ..
         'dbtemplates',
     )

   • Add dbtemplates.loader.load_template_source to the TEMPLATE_LOADERS list in the settings.py of your Django project

     It should look something like this:

     TEMPLATE_LOADERS = (
         'django.template.loaders.filesystem.load_template_source',
         'django.template.loaders.app_directories.load_template_source',
         'dbtemplates.loader.load_template_source',
     )

4. Sync your database python manage.py syncdb

5. Restart your Django server

Usage

Creating database templates is pretty simple: Just open the admin interface of your Django-based site in your browser and click on “Templates” in the “Dbtemplates” section.

There you only need to fill in the name field with the identifier, Django is supposed to use while searching for templates, e.g. blog/entry_list.html. The content field should be filled with the content of your template.

Optionally, by leaving the content field empty you are able to tell dbtemplates to look for a template with the name by using Django’s other template loaders. For example, if you have a template called blog/entry_list.html on your file system and want to save the templates contents in the database, you just need to leave the content field empty to automatically populate it. That’s especially useful if you don’t want to copy and paste its content manually to the textarea.

Caching

Using the default caching

Dbtemplates comes with different backends for caching that are automatically created, updated and deleted when templates are saved in the database by using Django’s signal framework.

To enable one of them you need to specify a setting called DBTEMPLATES_CACHE_BACKEND to one of the following values:

• dbtemplates.cache.FileSystemBackend – File system caching

  The FileSystemBackend is a simple way to store the templates you have in the database on the filesystem. That’s especially useful if you don’t use a full caching framework like Django is providing.

  To use this backend you need additionally create a setting DBTEMPLATES_CACHE_DIR that contains the full file system path to the directory where dbtemplates should create the cache files in.

• dbtemplates.cache.DjangoCacheBackend – Django cache

  The DjangoCacheBackend is a thin wrapper around Django’s caching framework that enables you to use advanced caching solutions like memcached or database caching. Please see the cache documentation if you want to know more about it.

Writing your own caching backends

Writing your own cache backends is perfectly easy since dbtemplates includes a easy-to-use base class in dbtemplates.cache.BaseCacheBackend.

Just subclass that base backend somewhere in your own code and provide the follwing three reuqired methods:

• load

  Loads a template from the cache with the given name and returns its contents. Return None if nothing found.

  Arguments:

  • name - name of the template

• save

  Saves the passed template contents with the passed name in the cache.

  Arguments:

  • name - name of the template

  • content - contents of the template

• remove

  Removes the template with the passed name from the cache.

  Arguments:

  • name - name of the template

Please see also the source of the default backends to see how it works.

Versionizing your templates

dbtemplates comes prepared to use the third party Django app django-reversion, that once installed besides dbtemplates allows you to jump back to old versions of your templates. It automatically saves every state when you save the template in your database and provides an easy to use interface.

Please refer to django-reversion’s documentation for more information about how it works. dbtemplates automatically recognizes if django-reversion is installed and works out of the box. Just visit the “History” section of each template instance and browse its history.

Short installation howto

1. Get the source from the django-reversion project site.

2. Edit the settings.py of your Django project:

   • Add reversion to the INSTALLED_APPS of your django site

   • Add reversion.middleware.RevisionMiddleware to the end of the MIDDLEWARE_CLASSES list.

     It should look something like this:

     MIDDLEWARE_CLASSES = (
         'django.contrib.sessions.middleware.SessionMiddleware',
         'django.middleware.common.CommonMiddleware',
         'django.middleware.cache.CacheMiddleware',
         # ..
         'reversion.middleware.RevisionMiddleware',
     )

3. Sync your database with python manage.py syncdb

Support

Please leave your questions and messages on the designated Google Code site:

http://code.google.com/p/django-dbtemplates/