LinkModel Example

models.py

from ....

class LinkBase(models.Model):
    link_text = models.CharField(verbose_name=_('Link Text'), max_length=255,
                                 blank=True, default='')
    link_type = models.CharField(verbose_name=_('Link'), max_length=20, choices=LINK_TYPE_CHOICES,
                                 blank=True, default='')
    page = PageField(null=True, blank=True)
    file = FilerFileField(null=True, blank=True, related_name='link')
    mailto = models.EmailField(null=True, blank=True)
    external = models.URLField(null=True, blank=True)
    free = models.CharField(max_length=512, null=True, blank=True)

    class Meta:
        abstract = True

    def get_link(self):
        if self.link_type:
            for key, display in LINK_TYPE_CHOICES:
                if not key == self.link_type:
                    setattr(self, key, None)
        if self.page:
            if self.page.site.id == settings.SITE_ID:
                return self.page.get_absolute_url()
            else:
                return 'http://' + self.page.site.domain + self.page.get_absolute_url()
        elif self.file:
            return self.file.url
        elif self.external:
            link = self.external
            if not link.startswith('http'):
                link = 'http://%s' % link
            return link
        elif self.mailto:
            return "mailto:%s" % self.mailto

    def get_link_text(self):
        obj = None
        if self.name:
            return self.name
        if self.link_type:
            obj = getattr(self, self.link_type, None)
        elif self.page:
            obj = self.page
        elif self.file:
            obj = self.file
        elif self.external:
            return self.external
        elif self.mailto:
            return self.mailto

        if not object is None:
            return unicode(obj)
        return ''

    def get_link_type(self):
        if self.link_type:
            return self.link_type
        if self.page:
            return "page"
        elif self.file:
            return "file"
        elif self.external:
            return "external"
        elif self.mailto:
            return "mailto"

    def get_link_target(self):
        type = self.get_link_type()
        if type in ['file', 'external']\
                or type == 'page' and not self.page.site.id == settings.SITE_ID:
            return "_blank"
        return ""

templatetags.py

from lxml.html import fragment_fromstring, tostring
from django import template
from django.template.defaultfilters import stringfilter

from my.models import Link

register = template.Library()


@register.filter
@stringfilter
def whatever_add_links(html):
    fragment = fragment_fromstring("<div>" + html + "</div>")
    links = fragment.cssselect('a')
    for link in links:
        if link.get('data-link_type', None):
            kwargs = {}
            dummy_link = LMLink()
            for key, value in link.items():
                if key.startswith('data-'):
                    new_key = key.replace('data-', '', 1)
                    if new_key == 'page_2':
                        new_key = 'page'
                    if hasattr(dummy_link, new_key):
                        if hasattr(dummy_link, new_key + "_id"):
                            # set fk directly
                            new_key = new_key + "_id"
                            if not value:
                                value = None
                        kwargs[new_key] = value
                        link.attrib.pop(key)
            real_link = LMLink(**kwargs)
            link.set('href', real_link.get_link())
    return tostring(fragment)