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Exists Filter OneToOneField in Admin

Adds Boolean like Filter in Admin to OneToOneField reference. Allowing to filter in the Parent for instances without Referenced Field. To register the filter, import in `urls.py` for example: import filterspecs Example `models.py`: from django.db import models class Place(models.Model): name = model.CharField(maxlength=50) address = model.CharField(maxlength=80) class Restaurant(meta.Model): place = model.OneToOneField(Place) place.exists_filter = True serves_hot_dogs = model.BooleanField() serves_pizza = model.BooleanField() Example `admin.py`: from django.contrib import admin from models import * class PlaceAdmin(admin.ModelAdmin): list_filter = ('restaurant',) admin.site.register(Place, PlaceAdmin) With this example PlaceAdmin will have a filter: By Restaurant All Yes No Where `Yes` will list `Place` with `Restaurant` instances, and `No` will list `Place` without `Restaurant` instances.

  • admin
  • filters
  • OneToOneField
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Automatically create urls for templates in a directory

When developing a site, I sometimes want to be able to visually reference the HTML before it's given a real context, and a view. This extra bit of code will allow you to add a directory within your templates dir, and pull any html files and subdirectories from it. I added the if statement to automatically use an index.html file if there's no file and extension at the end. You can substitute anything you like for the "html" in "(?P<base>html)". That's just passed as an argument to prepend to the template as a base directory for the templates.

  • urls
  • templates
  • direct_to_template
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Property Attributes in Memcache

Memcached Property Attributes ----------------------------- Setting the attribute will store the value in memcached; accessing the attribute will retrieve from memcached. Most useful as a way of simulating memcached "fields" on model instances. See the docstring for details.

  • cache
  • memcached
  • descriptors
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Author: ori
  • 0
  • 0

Disable ordering in the admin for a model

Django admin orders models by their primary key by default, which can be undesirable on very large tables. This shows how to disable any ordering on a model. Note that this behavior is fixed in 1.4 trunk.

  • admin
  • ordering
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Multiple User subclasses custom Auth backend

A project I'm working on requires multiple different classes of users, all with different fields/attributes. Having a single UserProfile class with a generic relation was a complete pain in practice. So, I changed my classes to all subclass User directly and then used django-model-utils to create a custom ModelBackend that returns the appropriate class when accessing request.user. The InheritanceQuerySet manager provided by django-model-utils makes it all possible and with only a single database query. No need to add anything directly to the User class, by the way. Just subclass it directly with each of your custom classes: class CustomUser1(User): field1 = models.CharField(...) class CustomUser2(User): field2 = models.CharField(...)

  • user
  • profile
  • auth
  • subclass
  • backend
  • modelbackend
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create_c

Instead of creating a dictionary on every view everytime you could do this and just call it like c = create_c(request)

  • templates
  • request
  • data
  • csrf
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nested transactions context manager and decorator

This is a modification of Django 1.3's transaction.commit_on_success() decorator and context manager. It's inspired by snippet [1343](http://djangosnippets.org/snippets/1343/) which unfortunately don't work in current Django neither as a context manager. In my junior projects it works fine but I've not tested in critical projects yet! YMMV ! How it works: it simply counts the nesting level and does the real transaction enter/exit only on first call and last call respectively (code copied from Django's commit_on_success() ). It use thread local storage to save the per-thread nesting level count safely. To use it just put the code in a file (i.e. nested_commit_on_success.py) and import and use it exacly as normal commit_on_success(), both as decorator (@nested_commit_success) or context manager (with nested_commit_on_success(): ). Any feedback is welcome!

  • decorator
  • nested
  • transaction
  • contextmanager
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Update timestamp If any instance field has changed

Needed a function to check if any field in an instance has changed. If so update a datetime field to now to keep track of changes. This function is an override of the save function in the model.

  • fields
  • model
  • save
  • field
  • method
  • instance
  • override
  • compare
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models.py with django_dag models for parts hierarchy

This is a portion of my code for creating a hierarchical relation between assemblies, subparts, and parts and so forth (although really, everything is a Part) The project being used is [django_dag](https://github.com/elpaso/django-dag) For the sake of example, let's use this structure: * Bike 1 * - Front Tire & Back Tire combo 000 * - - Front Tire 000 * - - Rear Tire 000 * - Frame 000 * - Gearset type 000 * - - Crank 000 * - - Rear Cassette 000 * . * Bike 2 * - Front Tire & Back Tire combo 001 * - - Front Tire 001 * - - Rear Tire 000 * - Frame 001 * - Gearset type 000 * - - Crank 000 * - - Rear Cassette 000 Using the above example, I couldn't use a MPTT structure because Gearset 000 is used in 2 different parents (bike 1 and bike 2). So I had to use the DAG [(wiki)](http://en.wikipedia.org/wiki/Directed_acyclic_graph) structure which allows multiple parents. The `Relationship` model holds the dag information, mainly a parent and child field. (Tire combo 001 is child of Bike2, front tire 001 is child of tire combo 001, etc) After get the dag structure using the `ancestors_tree` method on a Part object, I search for the BillOfMaterial info for that whole tree. In my case the Bill Of Material info is unique per assembly, so that's why there are seperate models. It becomes a bit of a pain to have to save/delete both the relationship and BoM models at the same time, and to check if one exists to create the other etc. But I've made my first 'hack' through it to have a function project, and am ready to make some revisions now.

  • models
  • hierarchy
  • dhango_dag
  • django-dag
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PropertyBasedContext

This approach allows you to avoid code duplication to produce same context data for different views. It could be usefull when you are using templates inheritace.

  • context
  • contextprocessor
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