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Tag "model"

137 snippets

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Django Dictionary Model

This is a model that implements (most of) the python dictionary interface. Meaning, you can work with this model exactly like a python dictionary, and it handles querying the database for it's values, saving/deleting the helper objects, etc. I wrote this originally when I needed to store an arbitrary dictionary in the database, and decided to work it up into a near-complete implementation of a dictionary. In order to make sure that the dictionary is the most optimized possible, I have a static method that can be used for retrieval. Feel free to ignore it if you don't care about optimizing database queries. Here's an example: Python 2.6.1 (r261:67515, Jun 24 2010, 21:47:49) [GCC 4.2.1 (Apple Inc. build 5646)] on darwin Type "help", "copyright", "credits" or "license" for more information. (InteractiveConsole) >>> from binder.models import Dictionary >>> d = Dictionary.getDict('Foobar') >>> print d {u'Foobar': u'omgbbq', u'HAHAHAH': u"who's afraid of a big, black, bat?"} >>> d['pot'] = 'The kettle is black.' >>> print d {u'Foobar': u'omgbbq', u'pot': u'The kettle is black.', u'HAHAHAH': u"who's afraid of a big, black, bat?"} >>> print d['pot'] The kettle is black. >>> for k, v in d.iteritems(): ... print k +":", v ... Foobar: omgbbq HAHAHAH: who's afraid of a big, black, bat? pot: The kettle is black. >>> print d.keys() [u'Foobar', u'HAHAHAH', u'pot'] >>> print d.values() [u'omgbbq', u"who's afraid of a big, black, bat?", u'The kettle is black.'] >>> There's several more functions that I've implemented; check the code to see. (An interesting note: DictField saves immediately upon making a change, which is good to keep in mind in case that functionality isn't expected.) Hope someone finds this useful. :) --Chris

  • model
  • python
  • dict
  • dictionary
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Model Locking Mixin & Decorator (MySQL Advisory Locks)

This code provides a mixin and decorator which, when used together, can provide advisory locking on model methods. It provides locking by using MySQL's advisory lock system. See the example at the bottom of the code. This is a convenient and easy way to guarantee your model methods have exclusive access to a model instance. The LockableObjects class requires a MySQL backend, but it could be modified to use other back-end locking systems. The lock name generation in `LockableObject.get_lock_name()` could be altered to create much more complex locking schemes. Locking per-object, per-method for example.. Lock attempts have a timeout value of 45 seconds by default. If a timeout occurs, EnvironmentError is raised. **See the bottom of the script for an example** > **Instructions:** * **1:** Place the code in locking.py somewhere in your path * **2:** In your models.py (or any script with an object you want to lock): `from locking import LockableObject, require_object_lock` * **3:** In the model you want locking for, add the `LockableObject` mixin * **4:** Decorate the method you want to be exclusively locked with `@require_object_lock`

  • model
  • mysql
  • decorator
  • mixin
  • locking
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Author: pio
  • 0
  • 2

ModelList class

This class makes easier the job of rendering lists of model instances in django templates. It's intended to mimic the behavior of the Model Forms in that it contains the code needed to render it as an HTML table and makes it easy to handle all the model lists from a single view (as it's usually done with the generic views for creating and updating model instances). It also supports pagination and provides hooks for subclassing and customizing the rendered fields, column titles and list order. Basic example: `class Account(Model):` `name = models.CharField(max_length=MAX_LENGTH)` `responsible = models.CharField(max_length=MAX_LENGTH)` `email = models.EmailField()` `class AccountModelList(ModelList):` `class Meta:` `model = Account` `fields = ['name', 'responsible'] #email won't get a column` The model list would be instantiated with something like: `model_list = AccountModelList(instances=account_queryset)` Then a table header can be rendered with model_list.as_table_header(), while the table rows can be rendered calling as_table() on each model_list.items element.

  • model
  • pagination
  • table
  • list
  • model list
  • order by
  • render table
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URL models

You can use `UrlModel` to provide URL functionality to any instance of any model and any language (language support can be removed from this). Each model must have own view method, that returns HttpResponse. I was inspired by Flatpages. It is useful for small sites and static pages. `class Page(UrlModel): text = models.TextField() def view(self, request) # do something here return HttpResponse(...)`

  • middleware
  • urls
  • models
  • foreignkey
  • model
  • generic
  • url
  • foreign-key
  • genericforeignkey
  • contenttypes
  • 404
  • contenttype
  • content-type
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StateField

Based on [CountryField](http://www.djangosnippets.org/snippets/494/).

  • model
  • field
  • state
  • statefield
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Models with database views

This example shows, how to use database views with django models. NewestArticle models contains 100 newest Articles. Remember, that NewestArticle model is read-only. Tested with mysql.

  • sql
  • models
  • views
  • view
  • model
  • mysql
  • database
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CompressedTextField for Django 1.0+

This snippet updates http://www.djangosnippets.org/snippets/383/ for Django 1.0+, and adds support for sqlite3. Original snippet text: A CompressedTextField to transparently save data gzipped in the database and uncompress at retrieval.

  • text
  • model
  • field
  • compressed
  • gzip
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Dynamic growing model

This model is designed for my webshop. The Client-object is very 'stretch-able' by defining more fields to the client. These extra fields ares stored in the ClientConfig-object. Be sure to create a new Client-instance first and SAVE it! Without a client.id the ClientConfig won't work.

  • django
  • dynamic
  • model
  • example
  • client
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Custom optional abstract base attributes

I needed an abstract base class that can add attributes to the child classes based on the child's name. The attributes had to be implicit, but overridable, so all derived classes would get them by default, but they could be easily overriden in the child definition. So, the code code I came up with basically consists of a customized metaclass used by the abstract model.

  • model
  • abstract
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Author: tie
  • 0
  • 2

Q marshaller

Django supports the serializing model objects, but does not support the serializing Q object like that, ============================ q = Q(username__contains="findme") model0.objects.filter(q) serialize(q) # X ============================ so I wrote a little marshaller for Q, this is example, ============================ from django.contrib.auth import models as django_models qs = django_query.Q(username__contains="spike") | django_query.Q(email__contains="spike") _m = QMarshaller() a = _m.dumps(qs) # a was serialized. When call the similiar queries in page by page, you don't need to write additional code for creating same Q(s) for filtering models, just use the serialized Q as http querystring and in the next page unserialize and apply it. That is simple life.

  • model
  • python
  • q
  • query
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Manager for something like __inall

Provides the method from_related_ids, which lets you select some objects by providing a list of related ids (The huge difference to __in is that the objects have to match al of the ids, not only one) Model Example:: class Article(models.Model): text = models.TextField() tags = ManyToManyField('Tag') objects = AllInManager() Usage:: Article.objects.from_related_ids((1,2,3,4), 'tags')

  • model
  • db
  • manager
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autogenerated UUID model field

Provides UUIDField for your models. This version creates very short UUID represenation (21 chars) when the record is added eg. in admin. Generated ids are safe to be used in URLs. You can put represent it in admin as 'readonly_fields=("uuid",)'

  • model
  • field
  • uuid
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Gravatar support in model save override

Overridden save() method that adds Gravatar support for a user with a profile photo field (and presumably an email field). Checks to see if user has provided a photo. If not, then query Gravatar for a possible photo. Finally, if Gravatar does not have an appropriate photo for this user, then use whatever default photo is available (in this case, 'users/photos/default_profile_photo.png'... change as necessary).

  • model
  • save
  • override
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