import cStringIO
import ClientForm

def html_form_to_post_dict(content, base_uri):
    '''
    content: HTML string.
    
    Return a dictionary mapping form names to a dictionary
    with input values.

    {'form_name': {'input1: 'default text', ...} }

    Example usage in a django unittest.
        
    url=reverse('myapp.views.foo.edit', kwargs={'foo_id': foo_id})
    response=self.client.get(url) # client: django.test.Client
    post=html_form_to_post_dict(response.content, url)['foo']
    post['text']='my input'
    response=self.client.post(url, post)
    assert response.status_code==302, 'No redirect after POST. Form might contain errors?'
    foo=Foo.objects.get(id=foo.id)
    assert foo.text=='my input', u'Foo not updated: text: %s' % foo.text

    Needs ClientForm from: http://wwwsearch.sourceforge.net/ClientForm/
    '''
    fd=cStringIO.StringIO(content)
    forms={}
    for form in ClientForm.ParseFile(fd, base_uri, backwards_compat=False):
        old=forms.get(form.name)
        assert not old, 'Broken HTML: two forms with the same name %s %s' % (
            old.name, form.name)
        values={}
        for control in form.controls:
            if isinstance(control, (ClientForm.IgnoreControl, ClientForm.SubmitControl)):
                continue
            old=values.get(control.name)
            assert not old, 'Broken HTML: form %s contains the input name %s twice.' % (
                form.name, control)
            values[control.name]=control.value
        forms[form.name]=values
    return forms