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Snippet List

JSONField

This is a great way to pack extra data into a model object, where the structure is dynamic, and not relational. For instance, if you wanted to store a list of dictionaries. The data won't be classically searchable, but you can define pretty much any data construct you'd like, as long as it is JSON-serializable. It's especially useful in a JSON heavy application or one that deals with a lot of javascript. **Example** (models.py): from django.db import models from jsonfield import JSONField class Sequence(models.Model): name = models.CharField(maxlength=25) list = JSONField() **Example** (shell): fib = Sequence(name='Fibonacci') fib.list = [0, 1, 1, 2, 3, 5, 8] fib.save() fib = Sequence.objects.get(name='Fibonacci') fib.list.append(13) print fib.list [0, 1, 1, 2, 3, 5, 8, 13] fib.get_list_json() "[0, 1, 1, 2, 3, 5, 8, 13]" *Note:* You can only save JSON-serializable data. Also, dates will be converted to string-timestamps, because I don't really know what better to do with them. Finally, I'm not sure how to interact with forms yet, so that realm is a bit murky.

  • models
  • model
  • json
  • db
  • field
  • json-field
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Admin: ordering by multiple fields in a column sort

The new changelist supports clicking on a column header to order by that column, like iTunes. Unlike iTunes, which sorts by track number if you click the Artist or Album column header, it can only order by the column clicked on. By adding a property to my ModelAdmin, and subclassing ChangeList, I was able to make it also sort by track number when sorting by Artist or Album. [Blog post](http://python-web.blogspot.com/2010/07/sorting-by-more-than-one-field-in-admin.html) [Repository with full example](http://github.com/benatkin/tuneage)

  • admin
  • ordering
  • changelist
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TableSelectMultiple Widget

A widget for selecting from a list of `Model` instances using `MultipleChoiceField` which renders a table row for each choice, consisting of a column for a checkbox followed by a column for each item specified in `item_attrs`, which must specify attributes of the objects passed as choices.

  • forms
  • table
  • widget
  • selectmultiple
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Better debugging mail server

Python includes (and [Django recommends](http://docs.djangoproject.com/en/dev/topics/email/?from=olddocs#testing-e-mail-sending)) a simple email debugging server which prints mail to stdout. The trouble is, unlike any half-competent mail reader, long lines are broken up, and thus long URLs don't work without modification. This snippet simply unwraps long lines (broken by "=") so long URLs can be easily copied/pasted from the terminal. Save this snippet into a file named "better.py" and execute it.

  • mail
  • debuggingserver
  • long-lines
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Dynamic Test Loading

Ok... this is really a hack. But I love it. I hate setting up all of my test cases into suites, and making sure that I remember to add them each time I add a new python file... annoying! This allows me to have a tests package and then just add python files and packages to that test package (mirroring my app setup). Each of the files are then dynamically imported and every test case is automatically executed. If you don't want one to execute, add it to the ignore list. If you add 'views' to the ignore list, it will ignore all views, otherwise you would have to specify 'package.views' if it is in a package. So... in short this is a bit ghetto, but it saves me a lot of time just setting up all my tests... now I can just write them! Hope it's useful to someone. Greg

  • dynamic
  • unittest
  • load
  • test
  • loader
  • loading
  • unit
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Automatically generate admin

A management command to automatically generate a fully specified admin for the models in a specific app. It automatically generates raw_id_fields, search_fields, list_filter and more. It bases this on date fields, fields named as "name" or slug. Usage: ./manage admin_autogen <model>

  • django
  • scaffold
  • auto
  • django-admin
  • automatic
  • generation
  • generate
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Optimistic locking in Admin

Look here: https://bitbucket.org/depaolim/optlock The snippet of Marco De Paoli is much better than this one! :-) ========================================================= If two users save same record, the second one will overwrite first one. Use this snippet to achieve an optimistic locking, so the second user will get an exception. Save the snippet in optlock.py and put it anywhere in your pythonpath. **Do not put _version_opt_lock in readonly_fields** or the snippet will fail! (if you need to hide it, use jquery). The snippet need in request.POST the original value of _version_opt_lock and if you make it a readonly field Django doesn't POST its value. When this [bug](https://code.djangoproject.com/ticket/11277) will be fixed it should be possible to use a hiddeninput widget. models.py example: ... import optlock ... class YourModel(optlock.Model): ... admin.py example: ... import optlock ... class YourModelAdmin(optlock.ModelAdmin): ... That's it :-)

  • admin
  • locking
  • optimistic locking
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Amazon S3 browser-based upload form(FIXED)

This is a 'fixed' version of snippet [1868](http://djangosnippets.org/snippets/1868/) Changes: *Correctly handle the Content-Type, because amazon requieres it to be named with a dash and we can't use dashes in the form attributes declaration. *Also added max_size handling, with the corresponding update to the policy generation. *Added an example usage with some javascript for basic validation. [See the amazon reference](http://aws.amazon.com/articles/1434?_encoding=UTF8&jiveRedirect=1)

  • s3
  • amazon
  • html form
  • upload form
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simple jquery example

Displays an input with an add button. Clicking the add button creates a simple form - input with a submit button. Clicking the submit button will send the output to the server and return a value which is displayed.

  • ajax
  • jquery
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Alphabetic filter for admin

This snippet is based on [#748](http://www.djangosnippets.org/snippets/748/). Adds filtering by first char (alphabetic style) of values in the admin filter sidebar. The example below results in this filter: By name that starts with All A B G M X urls.py example (only for register the filter): import <your project>.admin.filterspecs models.py example: from django.db import models class Person(models.Model): name = models.CharField(max_length=40) name.alphabetic_filter = True admin.py example: class Admin: list_filter = ['name']

  • filter
  • admin
  • filterspec
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filter for extracting a number of paragraphs from any HTML code

From: [incredible times](http://incredibletimes.org) With inspiration from: [Unethical Blogger](http://unethicalblogger.com/2008/05/03/parsing-html-with-python.html) This code parses any provided HTML content, and extracts a number of paragraphs specified, with all the content and tags inside them. Example: Template variable "content" contains: <a href="#>some text</a> <p><strong>Testing</strong>testing testing this is a tester's life</p> <div>I wont see the world</div> <p>Another paragraph</p> So, place this code in any loaded template module (inside a templatetags folder of your app... i.e. myapp/templatetags/myutils.py) {% load myutils %} {{ content|paragraphs:"1"}} Would return: <p><strong>Testing</strong>testing testing this is a tester's life</p> Whereas {% load myutils %} {{ content|paragraphs:"2"}} Returns: <p><strong>Testing</strong>testing testing this is a tester's life</p> <p>Another paragraph</p>

  • filter
  • paragraph
  • html
  • parse
  • extract
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get_queryset_or_404

Sometimes we want to get a queryset or 404, for example, if we're passing our queryset to a subclassed generic view. This is identical to get_list_or_404 but returns a queryset.

  • shortcut
  • template
  • queryset
  • get_queryset_or_404
  • get_list_or_404
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Validation for full e-mails (e.g. "Joe Hacker <[email protected]>")

Out of the box, Django e-mail fields for both database models and forms only accept plain e-mail addresses. For example, `[email protected]` is accepted. On the other hand, full e-mail addresses which include a human-readable name, for example the following address fails validation in Django: Joe Hacker <[email protected]> This package adds support for validating full e-mail addresses. **Database model example** from django import models from full_email.models import FullEmailField class MyModel(models.Model): email = FullEmailField() **Forms example** from django import forms from full_email.formfields import FullEmailField class MyForm(forms.Form): email = FullEmailField(label='E-mail address') I maintain this code in a [GitHub gist](https://gist.github.com/1505228). It includes some unit tests as well.

  • forms
  • model
  • email
  • validation
  • orm
  • database
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