Auto Generate/Save Thumbnails using Template Filter (scale max_x, max_y, or both)

Couldn't get the original to work, and wanted more functionality (scale on x or y coordinates) <img src="{{ object.image.url }}" alt="original image"> <img src="{{ object.image|thumbnail:"250w" }}" alt="image resized to 250w x (calculated/scaled)h "> <img src="{{ object.image|thumbnail:"250h" }}" alt="image resized to (calculated/scaled)w x 250h h "> <img src="{{ object.image|thumbnail:"250x200" }}" alt="image resized to 250wx200h "> <img src="{{ object.image|thumbnail }}" alt="image resized to default 200w (or whatever you default it to) format"> Original http://www.djangosnippets.org/snippets/192/ Adapted http://www.djangosnippets.org/snippets/955/ Sampled From: http://batiste.dosimple.ch/blog/2007-05-13-1/ http://vaig.be/2008/05/17/stdimagefield-improved-image-field-for-django/

• template
• filter
• image
• template-filter
• thumbnail
• templatetags

Wed 06 Feb 2013 Read More

JSON-compatible query filter specification

This function is designed to make it easier to specify client-side query filtering options using JSON. Django has a great set of query operators as part of its database API. However, there's no way I know of to specify them in a way that's serializable, which means they can't be created on the client side or stored. `build_query_filter_from_spec()` is a function that solves this problem by describing query filters using a vaguely LISP-like syntax. Query filters consist of lists with the filter operator name first, and arguments following. Complicated query filters can be composed by nesting descriptions. Read the doc string for more information. To use this function in an AJAX application, construct a filter description in JavaScript on the client, serialize it to JSON, and send it over the wire using POST. On the server side, do something like: > `from django.utils import simplejson` > `filterString = request.POST.get('filter', '[]')` > `filterSpec = simplejson.loads(filterString)` > `q = build_query_filter_from_spec(filterSpec)` > `result = Thing.objects.filter(q)` You could also use this technique to serialize/marshall a query and store it in a database.

• filter
• ajax
• json
• database
• query

Sun 11 Jul 2010 Read More

Colorize Filter

I had a need to colorize the nicks for the new DjangoBot Logger. Instead of managing a collection of names and corresponding colors we decided it would be more simple to just "hash" the nickname using a colorize filter. This causes the same nickname to always appear in the same color.

• filter
• colorize

Sun 11 Jul 2010 Read More

Currency filter

Formats a number in the local currency format. E.g., if `foo` is equal to `49277`, then > ` {{ foo|currency }}` would print > `$49,277` If your locale is the U.S. You can use this filter in your templates as described in the [Django documentation](http://www.djangoproject.com/documentation/templates_python/)

• filter
• templatetags
• money
• currency
• dollars

Fri 31 Jul 2015 Read More

Link filter

Almost too dumb to be worth posting but its saved me a lot of typing. Instead of: <div> <a href="{{ object.get_absolute_url }} class="object-icon">{{ object }}</a> </div> just put: <div>{{ object|link }}</div>

• filter
• links

Sun 11 Jul 2010 Read More

Enhanced "avoid widows" template filters

Building on [jcroft's snippet](http://www.djangosnippets.org/snippets/17/), here's a slightly more advanced version which has two filters, one for basic text and the other for html snippets. Usage is like so: <h2>{{ blog_entry.headline|escape|widont }}</h2> {{ blog_entry.html|widont_html }} On top of Jeff's reasons for using these filters, they are important because they help keep one of [God's commandments](http://www.ebible.com/bible/NIV/Exodus+22%3A22). ;)

• filter
• widows
• typography
• widont

Thu 22 Dec 2011 Read More

Humanize lists of strings in templates

A simple template filter for taking a list and humanizing it, converting: `["foo", "bar"]` to `"foo and bar"` `["foo", "bar", "baz"]` to `"foo, bar and baz"` `["foo", "bar", "baz", "42"]` to `"foo, bar, baz and 42"`

• filter
• lists
• filters
• humanize

Sun 11 Jul 2010 Read More

email_links

A very basic app centered around a template tag that takes an e-mail address and optional label and returns a link to an e-mail form. This way, you can easily throw e-mail addresses into your template that will automatically link to an e-mail form instead of displaying the e-mail address itself. The model for this app is extremely simple, with only one field to store the e-mail address. When an e-mail is passed to the email_link template tag, the e-mail address is added to the database if it is not already there. This is stored in the database in order to keep the full e-mail address hidden from the viewer. To use, simply create an app called 'email_links' (or you can change the name if you also change line 4 of email_extras.py to reflect the change). Then use the models.py and views.py provided. Add a templatetags directory under your app, and add email_extras.py and a blank __init__.py In your urls.py, add the following to your urlpatterns (subsitute project_name for your own): `(r'^email/(?P<email_id>[0-9]+)/$', 'project_name.email_links.views.email_form'),` Create two templates: email_links/email_form.html and email_links/thanks.html (the examples here are extremely basic - make them however you want). Finally, in a template where you want to provide a link to e-mail someone, first load email_extras: `{% load email_extras %}` Then do one of the following: `{% email_link "[email protected]" %}` `{% email_link "[email protected]" "E-mail someone" %}` Both will create a link to the e-mail form. The first will use mask_email (from the snippet by jkocherhans) to create the link. The second will display the second argument "E-mail someone" in the link. Also note that I've used the Sites add-on to generate the links, but you can easily change this to suit your needs. I hope all of this makes sense. I'm a bit tired, but wanted to get this up before bed.

• filter
• tag
• email

Fri 16 Sep 2011 Read More

split filter

**Usage** (*in template*): <img src="{{ MEDIA_URL }}2007/images/{% filter split:","|random %}theimage1.jpg,something2.jpg,thirdisthecharm.jpg{% endfilter %}" /> I decided to make it simple, because one template creator wanted to add random images to different places of templates. Creating something huge, like external image filename parsing was not necessary in this case.

• filter
• split

Wed 25 May 2011 Read More

Slugify alternative

I prefer to use this slugification function rather than the one included with Django. It uses underscores instead of dashes for spaces, and allows dashes and periods to occur normally in the string. I decided on this when considering reasonable slugified titles such as... object-relational_mapper_2.5 ten_reasons_web-2.0_rocks django-trunk_0.99_updated

• filter
• slugs
• slug
• slugify

Sun 11 Jul 2010 Read More

Url filter middleware

How to config it ------------------ You can treat it as a micro url filter framework. Before you using it, you should setup some options about it. The option entry shoud be like this: FILTERS = ( (r'^user/(?P<user_id>\d+)/', 'apps.users.filter.check_valid_user'), ) FILTERS should be a list or tuple with two elements tuple item. The format should be like: (url_patterns, function) And url_patterns could be a single regex expression or a list/tuple regex expressions, So you can set multi regex expression in it. And the regulation is just like url dispatch, as above example, the url pattern is: r'^user/(?P<user_id>\d+)/' So you can see, you can set parameter name `user_id`, then it'll be passed to the function behind. Function can be a string format, just like above example, and it can be also a real function object. It'll only impact request. How to write filter function ------------------------------- According above example, I define a url pattern, and what to check if the user is a valid user, and if the user is visiting his own urls, so the filter function could be: from django.contrib.auth.models import User from utils.common import render_template def check_valid_user(request, user_id): if request.user.is_anonymous(): return render_template(request, 'users/user_login.html', {'next':'%s' % request.path}) try: person = User.objects.get(pk=int(user_id)) except User.DoesNotExist: return render_template(request, 'error.html', {'message':_("User ID (%s) is not existed!") % user_id}) if person.id != request.user.id: return render_template(request, 'error.html', {'message':_('You have no right to view the page!')}) I think the code is very clear. And you can use it filtermiddleware to do like user authentication check, and other checking for url. BTW, render_template is comes from [Snippets #4](http://www.djangosnippets.org/snippets/4/)

• middleware
• filter
• url

Tue 02 Sep 2014 Read More

getattr template filter

Put inside `mysite/templatetags/getattr.py` Add `mysite` to your `INSTALLED_APPS` In your template: {% load getattr %} {{ myobject|getattr:"theattr,default value" }} Thanks to pterk for optimizations! \\o/

• template
• filter
• get

Sun 11 Jul 2010 Read More

AvaliabilityAtDateListFilter

If your model have two dates, start and end of something, you may want to have filter which allow you to show objects which last on specific day.

• filter
• admin
• changelist
• list_filter

Tue 10 Oct 2017 Read More

Filter changelist by a numeric field using a number of common value ranges

## How to use Use this [admin filter](https://docs.djangoproject.com/en/1.8/ref/contrib/admin/#django.contrib.admin.ModelAdmin.list_filter) together with a numeric field to allow filtering changlist by field values range (in this case, age groups): For example, to group customers by age groups: class Customer(models.Model): # ... age = models.IntegerField() age.list_lookup_range = ( (None, _('All')), ([0, 2], '0-2'), ([2, 4], '2-4'), ([4, 18], '4-18'), ([18, 65], '18-65'), ([65, None], '65+'), )) class CustomerAdmin(admin.ModelAdmin): list_filter = [('age', ValueRangeFilter), ] ## Inspiration [This snippet](https://djangosnippets.org/snippets/587/) (for django < 1.4) inspired me to make this work for newer django versions.

• filter
• admin
• field
• range

Fri 04 Sep 2015 Read More

Datetime adjuster for Django Templates

The filter is **specific to datetime objects** and no allowance has been made to convert strings or epoch times. Also **no type checking** is performed so misuse will result in an error. To use include the above snippet in a file called templatetags/customfilters.py or append to existing filters file then load: `{% load customfilters %}` in your template, then to use it: `{{ dateobject|adjust:"months=1"|date:"Y/m/d" }}` To push the dateobject forward by a month, or: `{{ dateobject|adjust:"weeks=-1"|date:"Y/m/d" }}` To push the dateobject back a week, or: `{{ dateobject|adjust:"years=1, months=2"|date:"Y/m/d" }}` To push the dateobject forward by a year and 2 months

• template
• filter
• datetime
• calculation
• adjust
• relativedelta

Thu 23 Jul 2015 Read More