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Lazily lookup dynamically for templates

If you've ever wanted to dynamically lookup values in the template layer (e.g. `dictionary[bar]`), then you've probably realized/been told to do this in the python layer. The problem is then you often to build a huge 2-D list to hold all of that data. These are two solutions to this problem: by using generators we can be lazy while still making it easy in the python layer. I'm going to write more documentation later, but here's a quick example: from lazy_lookup import lazy_lookup_dict def some_view(request): users = User.objects.values('id', 'username') articles = Article.objects.values('user', 'title', 'body') articles = dict([(x['user'], x) for x in articles]) return render_to_response('some_template.html', {'data': lazy_lookup_dict(users, key=lambda x: x['id'], article=articles, item_name='user')}) Then in the template layer you'd write something like: {% for user_data in data %} {{ user_data.user.username }}, {{ user_data.article.title }} {% endfor %}

  • template
  • dynamic
  • lookup
  • lazy
  • dynamic-lookup
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improved getattr template filter

I tried to use [Joshua's](http://www.djangosnippets.org/users/joshua/) nice and very useful [getattr template filter (#38)](http://www.djangosnippets.org/snippets/38/), but ran into a few problems. I used it on objects outside of my control (admin internals, coughcough) and on some of them the code didn't catch the resulting exceptions. So I improved the error handling a bit. Furthermore, the code now also returns the *value of a callable* instead of the callable *itself* (last 4 lines). Looking at my code though, it can certainly be improved further.

  • template
  • filter
  • get
  • attr
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Template Context Debugger with Pydev

This snippet is a variation on snippet 1550 that works with the Eclipse pydev plugin. This allows you to set up a breakpoint anywhere in your template code, by simply writing {% pydev_debug %}. Be sure to launch pydev in debugger mode first. Once you're in the debugger, you can explore the stack and quickly find which context variables are set. This can be especially useful inside for loops, etc., where you want to see how the templating code is mucking with the context. This can also be useful when your templates are ultimately rendered by code that might not understand very well, such as generics.

  • template
  • debug
  • pydev
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Expand(flatten) url patterns

This is a small function for those time when you want a list of all your urls, expanding included urls, so in the end is like all your urls are in one module. This function recursively does it, so it doesnt matter how nested the includes are in the end you get one flat list.

  • urlpatterns
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Dictionary of choices based in models

Sometimes we need to build a ChoiceField from data in a Model or more than just one model via fk's but the ModelChoiceField is not *that* flexible. So, in order to obtain a list of tuples with pk and a descriptive text for the choices parameter of the ChoiceField use this little function.

  • forms
  • choicefield
  • zip
  • list-of-tuples
  • orm-and-forms
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Tatsypie: additional list endpoints for custom Model's manager methods

Although configuring filtering in TastyPie is possible, it is limited to per-field filters, which are not enough for more complex filtering. If your model implement custom manager methods for complex filters, exposing these methods as TastyPie Resource list endpoints is not an easy task. The ModelResource subclass provided here does this, providing 3 ways of complex filtering: * define querysets for filters directly in the Resource declaration * use Model manager custom method * use QuerySet custom method

  • managers
  • manager
  • custom-manager
  • tastypie
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FileField with file extension whitelist

A simple FileField with a addition file extension whitelist. Raised ValidationError("Not allowed filetype!") if a filename contains a extension witch is not in the whitelist.

  • forms
  • filefield
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