HTTP basic auth decorator

This is a somewhat simpler alternative to [http://www.djangosnippets.org/snippets/243/](http://www.djangosnippets.org/snippets/243/) that does not return a 401 response. It's meant to be used along with the login_required decorator as an alternative way to authenticate to REST-enabled views. Usage: @http_basic_auth @login_required def my_view(request): ... If an HTTP basic auth header is provided, the request will be authenticated before the login_required check happens. Otherwise, the normal redirect to login page occurs.

• basic
• authentication
• decorator
• auth

Sun 11 Jul 2010 Read More

ManyToManyField no syncdb

**Sumary** M2M relation without creating table. Normally you should specify m2m only in *one* model, thus widgets for many-to-many relations will be displayed inline on whichever model contains the actual reference to the ManyToManyField. But if you want to be able to have widgets displayed on both form you need some tricks, for example using intermediary-models can help, but you will not get multiselect widget (and in case of inlining extra = multi). Also you can write your own form which takes care about adding widget (just 1 line) and setting default values and saving it (more than few lines of code). If you try ManyToManyField with same db_table specified, the only problem will be in syncdb (it will try to create two identical tables) and the only thing our class does is preventing creation of table for M2M, so in one model you should use ManyToManyField and in another ManyToManyField_NoSyncdb with the same db_table argument. **Example** So to have M2M widgets in both forms you can write: class User(models.Model): #... groups = ManyToManyField('Group', related_name='groups', db_table=u'USERS_TO_GROUPS') class Group(models.Model): #... users = ManyToManyField_NoSyncdb(User, related_name='users', db_table=u'USERS_TO_GROUPS')

• model
• field
• manytomany
• manytomanyfield
• syncdb

Thu 18 Aug 2011 Read More

Complex Formsets

Background ========== Edit: This snippet doesn't make a lot of sense when Malcolm's blog is down. Read on for some history, or go [here](http://www.djangosnippets.org/snippets/1955/) to see the new trick that Malcolm taught me. A year ago, Malcolm Tredinnick put up an excellent post about doing complex Django forms [here](http://www.pointy-stick.com/blog/2008/01/06/django-tip-complex-forms/). I ended up reinventing that wheel, and then some, in an attempt to create a complex formset. I'm posting my (partial) solution here, in hopes that it will be useful to others. Edit: I should have known - just as soon as I post this, Malcolm comes back with a solution to the same problem, and with slightly cleaner code. Check out his complex formset post [here](http://www.pointy-stick.com/blog/2009/01/23/advanced-formset-usage-django/). I'll use Malcolm's example code, with as few changes as possible to use a formset. The models and form don't change, and the template is almost identical. Problem ======= In order to build a formset comprised of dynamic forms, you must build the forms outside the formset, add them, and then update the management form. If any data (say from request.POST) is then passed to the form, it will try to create forms inside the formset, breaking the dynamically created form. Code ==== To use this code: * Copy `BaseDynamicFormSet` into your forms.py * Create a derived class specific to your needs (`BaseQuizDynamicFormSet` in this example). * Override `__init__`, and keep a reference to your object that you need to build your custom formset (`quiz`, in this case). * Call the parent `__init__` * Call your custom add forms logic * Call the parent `_defered_init` To write your custom add_forms logic, remember these things: * You've got to pass any bound data to your forms, and you can find it in self.data. * You've got to construct your own unique prefixes by doing an enumerate, as shown in the example above. This is the same way it is usually handled by the formset. Add a `formset_factory` call, and specify your derived dynamic formset as the base formset - we now have a `QuizFormSet` class that can instantiated in our view. The view and template code look identical to a typical formset, and all of the dynamic code is encapsulated in your custom class. Warning ======= This solution does not yet handle forms that work with files, use the ordering/delete features, or adding additional forms to the set via javascript. I don't think that any of these would be that hard, but don't assume that they'll just work out of the box.

• formset

Sat 07 Aug 2010 Read More

Duplicate related objects of model instance

I've got a bunch of `Models` that form a tree like structure. I'd like to duplicate them all changing one field to something else. Say for example I've got a `Website` which has `Pages` and `Links` and all kinds of other `Models`. Each one of these belong to a `User` (through a foreign key relation). I could use `duplicate` to create a copy of an entire website and give it to another `User` with something like this: class Website(Model): owner = ForeignKey('auth.User') ... class Link(Model): owner = ForeignKey('auth.User') ... class Page(Model): owner = ForeignKey('auth.User') ... ################################## website = Website.objects.get(pk=1) new_owner = User.objects.get(pk=1) duplicate(website, new_owner, 'owner') For a in depth example of the problem see: [Duplicating Model Instances @ STO](http://stackoverflow.com/questions/437166/duplicating-model-instances-and-their-related-objects-in-django-algorithm-for-r) *Note* * Not tested with anything but simple Foreign Key relations - the model ordering is _very_ naive.

• copy
• duplicate
• denormalize

Sun 13 Feb 2011 Read More

Image resize on demand

** Image on demand view ** I often post photos on photography fora. Most fora want you to place a link to a photo somewhere on the net, but different fora have different rules. Some fora want you to stick to a maximum of 800 pixels wide, some 700 pixel and some even strange values like 639 pixels. My own site uses 600 pixels so I end up resizing images all the time. Since I keep my originals with my gallery as well (hidden for public viewing) resizing on the fly would be a nice asset. I'm using my previous snippet to apply a slight unsharp mask for better web display of my photos. ** usage ** This snippet takes the url to my photo application which is a simple link using the pk of my photo table and adds 'width'.jpg to the end (some fora check if the link is an image based on extenstion) The view takes the width requested and creates the resized image from the original full size image or takes it from the cache for display on demand. To prevent a dozen directories I use a setting to specify which widths are allowed, providing room for several versions of the same image. Any improvements are appreciated since I'm still rather inexperienced in Python and Django.

• image
• pil
• resize
• pythonmagick

Sun 11 Jul 2010 Read More

Rails-like MVC Controllers for Django

[See the blog entry](http://sciyoshi.com/blog/2008/nov/18/rails-mvc-controllers-django/) Allows using controllers for views. This allows for nice subclassing to override behavior of views. `Controller.urls` (see below) works fine for subclasses as well. Similar to [snippet #1165](http://www.djangosnippets.org/snippets/1165/) except that it won't break reverse URL resolving and regex validation in URLs. In `views.py`: import mvc class MyController(mvc.Controller): @mvc.view('myview/$', 'myview') def my_view(self): # do something with self.request return HttpResponse('something') class Meta(mvc.Controller.Meta): url_prefix = 'mycontroller-' In `urls.py`: from . import views urlpatterns = patterns('', # ... other urls here ... *views.MyController.urls(r'prefix/') ) Then the view `MyController.my_view` will be accessible from `'prefix/myview/'` and have the name `'mycontroller-myview'`, i.e. `reverse('mycontroller-myview')` will work as expected.

• rails
• controller
• mvc

Sun 11 Jul 2010 Read More

Add a print link to the admin to print individual record

This is a view that can be used to add a print button (link) in the admin change form for an individual record. Pretty simple to use. A nice enhancement to it is to be able to pull the model field name tie with the field value, something like making {{ object.as_dl }} available to the template. PS: The code is a modification from the django.views.generic.list_detail.object_detail

• print
• admin
• record

Tue 03 May 2011 Read More

SuperChoices

Seeing [snippet 1178](http://www.djangosnippets.org/snippets/1178/) reminded me that I also had a go at writing a Choices class at some point. I'm content with the result, but I doubt xgettext will discover your translation strings, which will no doubt be inconvenient. Here it is anyway, in all its overly-complicated glory :-) The following demo was pulled from the function's docstring tests. >>> simple = Choices("one", "two", "three") >>> simple Choices(one=0, two=1, three=2) >>> tuple(simple) ((0, u'ein'), (1, u'zwei'), (2, u'drei')) >>> (0, _('one')) in simple True >>> simple.ONE 0 >>> hasattr(simple, 'FOUR') False Ordering just follows the order that positional arguments were given. Keyword arguments are ordered by their value at appear after positional arguments. >>> [ key for key, val in simple ] [0, 1, 2] >>> Choices(one=1, two=2, three=3) Choices(one=1, two=2, three=3) A Mix of keyword and non-keyword arguments >>> Choices("one", two=2, three=3) Choices(one=0, two=2, three=3) Automatically generated values (for "one" below) should not clash. >>> Choices("one", none=0, three=1, four=2) Choices(one=3, none=0, three=1, four=2) Here is an example of combined usage, using different object types. >>> combined = Choices(one=1, two="two", three=None, four=False) >>> len(combined) 4 >>> (1, _('one')) in combined True >>> ('two', _('two')) in combined True >>> (None, _('three')) in combined True >>> (False, _('four')) in combined True And here is an empty choices set. Not sure why you would want this.... >>> empty = Choices() >>> empty Choices()

• models
• choices

Thu 30 May 2013 Read More

Address model

This is standart address model. Must match US / GB / French address and other... Specifics locales fields are notice by comments.

• model
• address

Wed 18 Sep 2013 Read More

SizeAndTimeMiddleware

Used for showing size of the page in human readable format and time taken to generate the page on the server. To use it, in your base template, somewhere put the line: `<!-- ____SIZE_AND_DATE_PLACEHOLDER____ -->`. May be used on production.

• middleware

Thu 24 Feb 2011 Read More

django_stateful

this snippet provides a class that can be subclassed for creating views that retain state between requests, you can read more here http://code.google.com/p/django-stateful/ your comments are welcome!

• django
• stateful
• seaside
• continuations

Sun 11 Jul 2010 Read More

Chunks template filter

A simple filter which divides an iterable (list, tupe, string, etc) in chunks, which can then be iterated over separately. A sample of the filter usage is given: a gallery template in which I needed to display images in a table, three images per row, one row for images followed by one row for their descriptions.

• template
• filter
• chunks
• for
• iterable

Sun 11 Jul 2010 Read More

StrictAuthentication - Auto log-out inactive users

This dead-simple piece of middleware adds a terrific security feature to django authentication. Currently, users who's accounts are de-activated still may have a cookie and a login session. This middleware destroys that session on their next request. Simply add this class into a middleware.py and add it to your settings.

• middleware
• authentication
• security
• sessions

Tue 10 Aug 2010 Read More

EncryptField

I was trying to create a custom field to use the mysql encrypt() function on some data I wanted to store in the DB. initcrash on IRC pointed me to [this code](https://tracpub.yaco.es/cmsutils/browser/trunk/db/fields.py?rev=66) which I butchered as best as my little brain could. Amazingly enough I got it working (thanks to a couple answers from initcrash). If anyone can clean this up that would be great. I'm also trying to figure out how I can a) create password reset link in the admin interface for this field without displaying the field or b) decrypt it so that the password field is pre-populated with the decrypted password. Otherwise it is submitting the encrypted string as a new password. Anyways, I'm only a week or two into Django with no python experience so any suggestions are very welcome. Hope this helps someone!

• mysql
• crypt
• custom-field
• encrypt()

Sun 11 Jul 2010 Read More

CheckedField

Here's a snippet to pair an arbitrary form Field type (the "target field") with a checkbox. If the checkbox is not selected, the cleaned_data value for the field will be None. If the checkbox is selected, it will return the target field's cleaned value.

• checkbox
• forms
• combining

Sun 11 Jul 2010 Read More