I have a list of items, each one with a checkbox to select it. I want
to post this info to a django view, but i don't know how should I use
the name="" and value="" of the input tag to gain access to it from
django as it if was an array.
The django way of form processing is using formmanipulators, a very typical for handling view looks like this:
@login_required
def add_label_to_post(request, blog_id):
blog = get_object_or_404(blogs, pk=blog_id)
if blog.owner_id != request.user.id:
return render_to_response('blogger/no_access', context_instance=DjangoContext(request))
manipulator = AddLabelsToPostManipulator(blog)
errors = new_data = {}
if request.POST:
# If data was POSTed
new_data = request.POST.copy()
# Check for errors.
errors = manipulator.get_validation_errors(new_data)
if not errors:
# No errors. This means we can save the data!
manipulator.do_html2python(new_data)
manipulator.save(new_data)
return HttpResponseRedirect("/blog/%s/" % id)
form = formfields.FormWrapper(manipulator, new_data, errors)
return render_to_response('blogger/add_label_to_post',
{'form': form},
context_instance=DjangoContext(request))
in short you should put all the details about form in a Manipulator class, and let it worry about validating and saving(whatever that means for your form) the form information. Django comes with a good collection of form items, or what can be called "widgets", they are defined in django/core/formfields.py, I recommend taking a look at the file itself as there is little documentation elsewhere, plus its pretty easy stuff [look for class FormField and its derived classes there].
For your case there is a CheckboxSelectMultipleField. To use it you have to define a Manipulator class:
class AddLabelsToPostManipulator(formfields.Manipulator):
def __init__(self, blog):
self.blog = blog
self.fields = (
formfields.TextField(field_name="url", is_required=True,
validator_list=[self.url_belongs_here]),
formfields.CheckboxSelectMultipleField (field_name = 'label_ids',
choices = [(label.id, label.name) for label in blog.get_label_list()],
is_required=True)
)
def url_belongs_here(self, field_data, all_data):
if not field_data.startswith(self.blog.url):
raise validators.ValidationError, "Post does not belong here."
def save(self, data):
# whatever you want to do to handle the form, save it to db, send some mail, whatever
# data is a dict, extract values, use data.getlist('label_ids') syntax when you are
# are expecting multiple values. it will return a list. for other values, u can use data['url']
# syntax. please note that if you do a data['label_ids'] which actually contains multiple
# values, django will give you the first value out of it.
# also there is no way to tell django if the values are infact integers, for multivalue selects,
# django will make sure all the values are in the choice list that you provided to the
# constructor, but when returning you the value, django will return you string representations
I used something like that in PHP:
...
<input type="checkbox" name="array[<?php echo $id; ?>]" value="1"> Text
Text
...
So I was able to know what item's where selected very easy. Just make a
loop through the array post var, and check what id's have a "1" value.
I suppose there's an easy way to do something like that in django, but
don't know how.
Need some help.
Thanks in advance.
--
Amit Upadhyay
Blog: http://www.rootshell.be/~upadhyay
+91-9867-359-701
