root/tags/amplee-0.5.0/amplee/examples/cooker/core/utils.py

# -*- coding: utf-8 -*-

import os.path
from StringIO import StringIO
import markdown
from xml.sax.saxutils import unescape
from bridge import Element as E

__all__ = ['transform_member_resource']

def transform_member_resource(member, xslt_path=None):
    """Transforms the member entry content from Markdown to HTML
    then returns a public version of the member entry.

    This entry can be used for the public feed aggregation for instance.

    You may pass the URI or path of an XSLT resource to be inserted as
    a processing instruction.
    """
    # To generate a public atom entry from the member resource
    # we first extract the content from the media resource
    info = member.collection.get_content_info(member.media_id)

    if not member.collection.contains(info, as_media=True):
        return

    # When using the TarFileStorage the returned path is in fact
    # a TarFileStoragePathInfo instance
    # But since we precisely know where to look in the tarball for the content
    # we specify exactly that we only want the content of the file
    # called 'recipe' within the tarball
    info.key.archive_sub_path = 'recipe'

    if not member.collection.contains(info, as_media=True):
        return
    
    # This returns the actual content as a string
    content = member.collection.get_content(info)[0][1]

    # Nextwe transform the Markdown content into XHTML
    recipe_html = u''
    if content:
        recipe_html = markdown.Markdown(content, safe_mode=True).toString()
        recipe_html = recipe_html.strip()

    # Now if we also have a image attached to this resource we
    # append the according Markdown entity so that it will
    # transform it into a <img /> XHTML tag
    if os.path.exists(os.path.join('static/photos/%s' % member.media_id)):
        title = member.atom.get_child('title', member.atom.xml_ns).xml_text
        recipe_html += '<img alt="%s" src="%s" title="%s" />' % (title, '/static/photos/%s' %
                                                                 member.media_id, title)
    
    recipe_html = unescape(recipe_html)
        
    # Finally we create a public atom entry from the member resource entry
    public = member.prepare_for_public(content=recipe_html, media_type=u'application/xml',
                                       xslt_path=xslt_path)

    # We indicate where the comments to the recipe will be found
    # by using RFC 4685
    attributes = {u'rel': u'replies', u'type': u'application/atom+xml',
                  u'href': u'%s/comments' % member.public_uri}
    E(u'link', attributes=attributes, prefix=public.xml_root.xml_prefix,
      namespace=public.xml_root.xml_ns, parent=public.xml_root)


    return public