Returns the first block or sentence of the first content-like
        field.

def description_from_content(self):
        """
        Returns the first block or sentence of the first content-like
        field.
        """
        description = ""
        # Use the first RichTextField, or TextField if none found.
        for field_type in (RichTextField, models.TextField):
            if not description:
                for field in self._meta.fields:
                    if (isinstance(field, field_type) and
                            field.name != "description"):
                        description = getattr(self, field.name)
                        if description:
                            from yacms.core.templatetags.yacms_tags \
                                                    import richtext_filters
                            description = richtext_filters(description)
                            break
        # Fall back to the title if description couldn't be determined.
        if not description:
            description = str(self)
        # Strip everything after the first block or sentence.
        ends = ("</p>", "<br />", "<br/>", "<br>", "</ul>",
                "\n", ". ", "! ", "? ")
        for end in ends:
            pos = description.lower().find(end)
            if pos > -1:
                description = TagCloser(description[:pos]).html
                break
        else:
            description = truncatewords_html(description, 100)
        try:
            description = unicode(description)
        except NameError:
            pass  # Python 3.
        return description