Get object/list or None
1. Function - get_obj_or_none Returns an object or a None Value 2. Function - get_list_or_none Returns a list object or None Value
- "get_obj_or_none"
- "get_list_or_none"
Snippet List
Arbitrary length formset
A formset class where you can add forms as you discover the need within your code. There is also the ability to add ManagmentForm fields. If you ever found yourself in a situation where 1) you have repeated forms that need to be displayed in different locations, or 2) if you find the application logic works better if you add forms as you discover you need them, this code will help you out. Below is pseudo code based on a real implementation I used. Each form had a save button and the SELECTED_PAYMENT field was set through JavaScript. It is very difficult to use JavaScript with repeated forms, without using a formset. from myProject.myApp import myFormsUtils from myProject.myApp.forms import PaymentForm SELECTED_PAYMENT = 'SELECTED_PAYMENT' # extra_fields format: {Field name: (Field type, Initial value)} l_extra_fields = {SELECTED_PAYMENT: (forms.IntegerField, -1)} PaymentFormSetType = myFormsUtils.formset_factory(PaymentForm, extra=0, extra_fields=l_extra_fields) if request.method == 'POST': paymentFormSet = PaymentFormSetType(data=request.POST) if paymentFormSet.is_valid(): li_curFormIdx = pagaFormSet.management_form.cleaned_data[SELECTED_PAYMENT] paymntForm = paymentFormSet.forms[li_curFormIdx] ... do stuff ... # To generate the formset paymentFormSet = PagamentoFormSetType() # You can re-add a form retrieved (as in the one above) l_form = paymentFormSet.add_form(paymntForm) # Or use the add function just like creating a new form l_form = paymentFormSet.add_form(personID=argPersonID, propID=argPropID, year=argYr, amt=lc_Amt) I then stored the `l_form` variables above directly into a unique Context structure and displayed them each individually in my template. Of course this also meant that I also had to output the `paymentFormSet.management_form` explicitly within my template. EDIT 09-11-2009: Modified the initial_form_count() method to properly handle initial form values in conjunction with dynamically added forms.
- form
- formset
- factory
- arbitrary-length
A view for downloading attachment
This view snippet is a helper for implementing file download handlers. There is a standard to encode Unicode filenames properly, but many browsers have different protocols. The default encoding is assumed to be UTF-8.
- view
- attachment
- send-file
- download-file
- mimetype
Save a model using an arbitrary db connection
This function lets you save an instance of a model to another database based on a connection argument. Useful when doing data migrations across databases. Connection is anything that would work as a django.db.connection I'm not sure if this handles proxy models or model inheritance properly, though.
- multi-db
- connection
Fix duplicate first page of paginated results
Search engines might conclude there's duplicate content if `/some_view/` and `/some_view/?page=1` returns the same results. This middleware redirects `?page=1` to the URL without the page parameter. You can set the name of the parameter in settings.py as `PAGE_VAR`. See [here](http://www.muhuk.com/2009/08/a-civilized-way-display-lots-of-data/) for more details.
- middleware
- pagination
- seo
- paginate
Persistent connection to PostgreSQL database
Hi, I made some small custom psycopg2 backend that implements persistent connection using global variable. With this I was able to improve the amout of requests per second from 350 to 1600 (on very simple page with few selects) Just save it in the file called base.py in any directory (e.g. postgresql_psycopg2_persistent) and set in settings DATABASE_ENGINE to projectname.postgresql_psycopg2_persistent This code is threadsafe, however because python don't use multiple processors with threads you won't get bit performance boost with this one. I really recommend using it in daemon mode. In apache mod_wsgi just set processes=8 threads=1
- database
- connection
- persistent
WebFaction fixes middleware
On WebFaction, each host has it's own Apache instance, with WebFaction's main Apache instance forwarding requests. This is very useful but means that some of the original information is lost. This middleware should be installed at the top of your list to restore this lost info. It includes the functionality that used to be in SetRemoteAddrFromForwardedFor before it was removed from Django.
- middleware
- ssl
- webfaction
- https
TinyMCE Widget
Widget for TinyMCE 3.2.6, a WYSIWYG HTML editor for `textarea`. **Note:** > This snippet uses the TinyMCE package thats contains special jQuery build of TinyMCE and a jQuery integration plugin. Anyway, is easily to adapt to standard package. Usage example: from django.contrib.flatpages.admin import FlatpageForm class MyFlatPageForm(FlatpageForm): content = forms.CharField(widget=TinyMCEEditor()) [TinyMCE download page](http://tinymce.moxiecode.com/download.php)
- forms
- wysiwyg
- form
- widget
- modelform
- tinymce
Middleware to reload translation for each request
This will reload the translation file for every request if you add it as a middleware in settings.MIDDLEWARE_CLASSES.
- middleware
- i18n
- cache
- reload
- translation
- reset
- rosetta
group_required decorator
This snippet provides a @group_required decorator. You can pass in multiple groups, for example: @group_required('admins','editors') def myview(request, id): ... Note: the decorator is based on the snippet [here](http://fragmentsofcode.wordpress.com/2008/12/08/django-group_required-decorator/) but extends it checking first that the user is logged in before testing for group membership - [user_passes_test](http://docs.djangoproject.com/en/dev/topics/auth/#django.contrib.auth.decorators.user_passes_test) does not check for this by default. It is important to check that the user is first logged in, as anonymous users trigger an AttributeError when the groups filter is executed.
- decorator
- auth
- groups
Template Filter: Add indentation
Template filter to add the given number of tabs to the beginning of each line. Useful for keeping markup pretty, plays well with Markdown. Usage: {{ content|indent:"2" }} {{ content|markdown|indent:"2" }}
- filter
- markup
- pretty
- indent
- indentation
Enhancing template tags with "as variable" syntax
Add the decorator to an already defined templatetag that returns a Node object: @with_as def do_current_time(parser, token): ... return a_node The decorator will patch the node's render method when the "as" syntax is specified and will update the context with the new variable. The following syntaxes are available: {% current_time %} {% current_time as time %} {{ time }}
- templates
- templatetags
Dynamic query builder with AND/OR
I recently had a need to build an iTunes style filtered search -- a user can add/subtract any number of filters whereby the are offered selects for fields they want to search, what type of search they wish to perform on that field (i.e., equals, contains, etc.), and then enter a value to search. Finally, they are provided the option to search all or any of the created filters. To keep things simple, I created this dynamic query builder. It takes a Model, plus lists of fields, types, values, and the chosen operator (and/or). Then, it constructs actual Q objects for each, performing a small sanity check to ensure a blank value has not been passed in. In the end, it returns either a filtered QuerySet or an empty result set to ensure that we can at least provide a message back to the user if nothing comes of trying to build the query. One would use it like so: results = dynamic_query(ModelName, fields_list, types_list, values_list, operator) if results: # do something else: # do something else
- dynamic-query-builder
- and-or-query-builder
Auto-rename duplicate fields
This is useful to run before you add a unique key to a character field that has duplicates in it. It just adds numbers to the end of the contents, so they will be unique. It takes a model class and a field name. The model class can be a South fake orm object, so this can be used inside data migrations.
- rename
- duplicate
- south
- unique-key
Printing inline formsets as UL / P
By default all forms created using inlineformset_factory are displayed as tables (because there is only a .as_table method) and there are no .as_p or .as_ul methods in them, so you need to do that by hand.
- django
- formset
- inline
- not-django-admin