Sorl-thumbnail has a sensible crop function in the default engine, but sometimes you need a little more control over the results. This post provides a custom cropping PIL engine that can be used to return specific, i.e. from (x1, y1) to (x2, y2), cropped thumbnails
If you update request.POST
or request.GET
in a view (or else where), any subsequent calls to request.REQUEST
will still return values from the old, outdated GET
and POST
dictionaries.
It's very easy to generate URLs to your django models using get_absolute_url(), but you can also use this pattern to just as easily create URLs to the admin page for your django models too. This post shows you how to make a get_admin_url() model method that generates links to give you quick access to your admin.
When using GenericRelations with Django to create unique generic foreign keys between objects, it can become tiresome having to navigate the RelatedManager every time you need to retrieve the single instance of the one-to-one relationship. This post shows how creating a quick Mixin
can help overcome this inconvenience.
Django's annotate method can be useful for counting particular attributes on every member of a queryset (i.e. count the number of books an author has). Unfortunately you can't use the ORM to do any filtering on those attribute. This would be useful for only considering an attribute if it were above a certain value, or belonged to a certain object (i.e. count the number of books with the tag 'Horror'). This post shows how to make use of the extra
method Django provides to create filtered annotations
Fandjango is a great application for getting a Facebook Canvas application up and running. It provides a nice view decorator to ensure a user is authorised with Facebook before allowing them access to that view. This post provides a piece of middleware that makes use of that decorator, allowing you to enforce Facebook authorisation on all views in your application.
When beginning with Django I always found it difficult to decide on basic project layouts. What should go where and why? Having read many of the great articles on the topic already out there this post outlines how I have come to manage the folder structure of most of my new Django projects, making sure everything is tidy and safe
When the generated URLs of your objects depends on a field in your model that could potentially change (for example a slug field that is generated from a title which your editor just changed), you can get yourself into trouble with Google as your old URL will now return a 404. This posts outlines an approach to dynamically create redirects whenever an objects changes an url dependant field.
If you are checking your settings.py into Git, make sure you aren't including any potentially sensitive information such as database passwords, secret keys and so on. A quick and easy way to avoid this is to create a separate sensitive.py
file.
Django's select_related QuerySet method is a great way to reduce the query count when joining tables but it should come with small print in the documentation. This post goes over that small print.