root/trunk/blog/forms.py

# vim: encoding=utf-8 :

import re
import urllib2
from lxml import etree

from django import newforms as forms
from django.contrib.sites.models import Site
from django.utils.translation import ugettext_lazy as _

from blog.models import Comment, TrackBack

REMOTELINK_PATTERN = re.compile(r'http://%s.*?' % Site.objects.get_current().domain)
MULTIBYTE_PATTERN = re.compile(u'.*[\u3041-\u3096]{2,}.*', re.M+re.U)
EMPTY_VALUES = (None, '')


class MultibyteCharField(forms.CharField):                                               
    """ 
    """ 
    def clean(self, value):
        super(MultibyteCharField, self).clean(value)                                     
        if value in EMPTY_VALUES:
            return u''
        if MULTIBYTE_PATTERN.search(value) is None:                                      
            raise forms.ValidationError(_(u'Ensure this value has at least 2 characters or more continuing of Hiragana.'))
        return value


class CommentForm(forms.ModelForm):
    """
    blog.Comment's form.
    """
    description = MultibyteCharField(label=_(u'comment'))
    class Meta:
        model = Comment
        fields = ('name', 'email', 'url', 'description')


class TrackBackForm(forms.ModelForm):
    """
    blog.TrackBack's form.
    """
    excerpt = MultibyteCharField(required=False)
    class Meta:
        model = TrackBack
        fields = ('entry', 'blog_name', 'title', 'url', 'excerpt')
    
    def clean(self):
        if not self._errors:
            try:
                try:
                    TrackBack.objects.get(entry__exact=self.cleaned_data['entry'],
                                          url__exact=self.cleaned_data['url'])
                    raise ValueError
                except TrackBack.DoesNotExist:
                    pass
                html = etree.parse(urllib2.urlopen(self.cleaned_data['url']),
                                   parser=etree.HTMLParser())
                links = '\n'.join(html.xpath('//a[@href]/@href'))
                if REMOTELINK_PATTERN.search(links) is None:
                    raise ValueError
            except Exception, e:
                raise forms.ValidationError(_(u'Invalid TrackBack.'))
        return super(TrackBackForm, self).clean()