The admin site uses a CSS class for each kind of field so that they can be styled easily. This snippet gives ModelForms a similar feature. See also: [James Bennett's explanation of formfield_callback](http://stackoverflow.com/questions/660929/how-do-you-change-the-default-widget-for-all-django-date-fields-in-a-modelform/661171#661171)
The Django Admin site provides a "raw ID" feature for foreign keys that reference large tables. In the form view, the label of the referenced object will appear after the input. This snippet will make that label into a hyperlink that takes you to the form view for that object. To use this snippet, copy base_site.html into your templates/admin directory (if you haven't already), and paste this code into that file somewhere after the 'extends "admin/base.html"' directive. If you are already using jQuery, you can remove the first script tag. If you are already extending "extrahead", just paste the script tag(s) into the block you have created. [Documentation for raw_id_fields](http://docs.djangoproject.com/en/dev/ref/contrib/admin/#django.contrib.admin.ModelAdmin.raw_id_fields)
Save this shell script to the root of your Django project as "tags.sh", make it executable with "chmod +x tags.sh", and run it from the project root with "./tags.sh", and you will have a "tags" file for vim and a "TAGS" file for emacs. Tags will be created for Python, JavaScript, and block names found in HTML templates. You may need to change "/usr/share/pyshared/django" to the location of your Django installation. Documentation on [Tags in emacs](http://www.gnu.org/software/emacs/manual/html_node/emacs/Tags.html) | [Tags in vim](http://vimdoc.sourceforge.net/htmldoc/tagsrch.html)
It is often convenient to be able to specify form field defaults via GET parameters, such as /contact-us/?reason=Sales (where "reason" is the name of a form field for which we want a default value of "Sales"). This snippet shows how to set a form's initial field values from matching GET parameters while safely ignoring unexpected parameters.
By default, a "Show all" link will appear in the changelist pager only if fewer than 200 records are in the result. Since it is rare that there will be more than one page of records yet fewer than 200, the "Show all" link almost never shows up. Pasting this code somewhere in your app will allow you to increase the 200-record maximum. "Show all" is very handy when used in combination with batch actions and filters, and this change will enable it for most situations. Note that this allows a changelist with up to 10,000 results, which results in a lot of HTML that can tax slower browsers and older machines. For me, it has been worth the tradeoff, since my users have fast enough computers and need to be able to make batch changes efficiently.
Returns a list of date objects for a given number of past days, including today. Useful for summaries of recent history. Inspired by [Template range filter](http://www.djangosnippets.org/snippets/1357/)