python - Django Tables - Column Filtering

Question

I started using django-tables2 (which I can highly recommend from the first impression) and I m asking myself how to implement column filtering. I do not find the appropriate documentation for it, but I m sure it is somewhere out there.

Answer 1

A little late answer but anyway ... I also couldn't find any appropriate documentation for column filtering. There are many methods to do it:

A. By hand: I add a form containing the fields I'd like to filter with and then I do something like this in my view:

  data = models.MyClass.all()
  form = forms.MyFilterForm(request.GET)
  if request.GET.get('field1'):
    data = data.filter(field1=request.GET.get('field1') )
  if request.GET.get('field2'):
    data = data.filter(field2=request.GET.get('field2') )   
  ...
  table = tables.MyTable(data)

This works very nice however it's not so DRY because it is hard coded in the view.

B. Using a SingleTableView: Another way is to add a SingleTableView that contains the form:

from django_tables2 import SingleTableView
class FilteredSingleTableView(SingleTableView):
  def get_table_data(self):
    data= models.MyClass.objects.all
    if self.request.GET.get('field1'):
      data = data.filter(field1=self.request.GET.get('field1') )
    if self.request.GET.get('field1'):
      data = data.filter(field1=self.request.GET.get('field1') )
    return data

    def get_context_data(self, **kwargs):
      context = super(FilteredSingleTableView, self).get_context_data(**kwargs)
      context['form'] = forms.MyFilterForm(self.request.user, self.request.GET)
      return context

This is more DRY :)

C. Using SingleTableView and django_filters: This probably is the most DRY way :) Here's how to do it:

First define a filter:

class MyFilter(django_filters.FilterSet):
  field1 = django_filters.CharFilter()
  field2 = django_filters.CharFilter()
...

(or you can add a model filter in Meta ( model = MyModel)

Now, create a SingleTableView like this

class FilteredSingleTableView(SingleTableView):
  def get_table_data(self):
    f = filters.MyFilter(self.request.GET, queryset =models.MyClass.objects.all() , request=self.request )
    return f

  def get_context_data(self, **kwargs):
    context = super(FilteredSingleTableView, self).get_context_data(**kwargs)
    f = filters.MyFilter(self.request.GET, queryset =models.MyClass.objects.all() , request=self.request )
    context['form'] = f.form
    return context

(probably there is a problem with the line f =... but I couldn't make it work otherwise.

Finally, you can call the SingleTableView from your urls.py like this

url(r'^$', views.FilteredSingleTableView.as_view(
    table_class = tables.MyTable, 
    model=models.MyClass, 
    template_name ='mytemplate.html', 
    table_pagination={ "per_page":50 } )) , 
    name='filtered_single_table_view'
),

D. Using a generic class: This is an even more DRY and django-generic-class-views like way! This is actually the next step from C: Just declare your FilteredSingleTableView like this:

class FilteredSingleTableView(django_tables2.SingleTableView):
  filter_class = None

  def get_table_data(self):
    self.filter = self.filter_class(self.request.GET, queryset =super(FilteredSingleTableView, self).get_table_data() )
    return self.filter.qs

  def get_context_data(self, **kwargs):
    context = super(FilteredSingleTableView, self).get_context_data(**kwargs)
    context['filter'] = self.filter
    return context

Now the FilteredSingleTableView has a parameter for the class of the filter so you may pass it in your urls.py among the other parameters:

    url(r'^$', ships.views.FilteredSingleTableView.as_view(
        model=models.MyModel,
        table_class=tables.MyTable, 
        template_name='mytemplate.html' , 
        filter_class = filters.MyFilter, 
    ) , name='myview'),

So you can use FilteredSingleTableView without modifications for filtering any of your models !!

Also notice that I've now saved the filter as an instance variable and removed the repetitive code f=filters.MyFilter(...) that I had in C (get_table_data is called before get_context_data - if that was not always the case then we could add an get_filter instance method that would do the trick) !

Update 23/04/2016: After popular demand, I've created a simple Django project that uses the generic FilteredSingleTableView class to filter a table of books. You may find it out at: https://github.com/spapas/django_table_filtering

Update 05/07/2016: Please notice that you should use return self.filter.qs for the get_table_data return in D (I've alread updated the answer with this) or else the view will take too long to render for big tables -- more info can be found on https://github.com/spapas/django_table_filtering/issues/1