Source Code for Module amplee.atompub.member.media

  1  # -*- coding: utf-8 -*- 
  2   
  3  __doc__ = """ 
  4  This module defines a set of member classes aiming at 
  5  dealing with media formats supported by the Hachoir library: 
  6  http://hachoir.org/wiki/hachoir-parser 
  7   
  8  Therefore this module requires the Hachoir library (core and meta_data): 
  9  http://hachoir.org/ 
 10  """ 
 11   
 12  from datetime import datetime 
 13  import os 
 14  from xml.sax.saxutils import escape 
 15   
 16  from bridge import Element, Attribute 
 17  from bridge.common import ATOM10_PREFIX, ATOMPUB_PREFIX, XML_PREFIX, XML_NS, \ 
 18       ATOM10_NS, ATOMPUB_NS 
 19   
 20  from amplee.utils import generate_uuid_uri, get_isodate 
 21  from amplee.error import MemberMediaError 
 22  from amplee.atompub.member import MediaMember 
 23  from amplee.atompub.member.helper import MemberHelper 
 24   
 25  from hachoir.error import HachoirError 
 26  from hachoir.stream import InputStreamError, InputSubStream 
 27  from hachoir_parser import guessParser 
 28  from hachoir_metadata import extractMetadata 
 29   
 30 -class HachoirMember(MediaMember): 
 31 -    def __init__(self, collection, source, slug=None, title=None, 
 32                   description=None, media_type=None, ext=None, 
 33                   entry_id_creator=None, name_creator=None, **kwargs):  
 34          """ 
 35          Creates a member based Hachoir capabilities. 
 36   
 37          Keyword arguments 
 38          collection -- parent collection 
 39          source -- fileobj of data to handle 
 40          title -- title to use for the Atom entry. If not provided it will be extracted 
 41          from the resource metadat if any.  
 42          description -- summary to use for the Atom entry. If not provided it will 
 43          extracted from the metadata if any. 
 44          name_creator -- callable to generate the last segment of URIs used for 
 45          this resource 
 46          ext -- extension to use for the media resource 
 47          media_type -- mime type of the media resource 
 48          entry_id_creator -- callable which will return the id 
 49          to use in the atom:id element (as an unicode object) 
 50   
 51          The name_creator and the entry_id_creator function must takes the following parameters: 
 52          collection, abs_path, metadata (a hachoir_metadata.metadata instance), slug, ext 
 53          """        
 54          MediaMember.__init__(self, collection, media_type=media_type) 
 55   
 56          metadata = self.__get_meta_data(source) 
 57           
 58          name = slug 
 59          if callable(name_creator): 
 60              name = name_creator(collection, abs_path, metadata, slug, ext) 
 61   
 62          media_id = member_id = name 
 63          if self.collection.member_extension: 
 64              member_id = u'%s.%s' % (name, self.collection.member_extension) 
 65   
 66          self.media_id = media_id 
 67          self.member_id = member_id 
 68   
 69          if callable(entry_id_creator): 
 70              id = entry_id_creator(collection, abs_path, metadata, slug, ext) 
 71          else: 
 72              id = generate_uuid_uri() 
 73               
 74          mh = MemberHelper(self.collection) 
 75          mh.initiate(id=id) 
 76          mh.add_element('title', content=name, attributes={u'type': u'text'}) 
 77          mh.add_element('summary', unicode(description), attributes={u'type': u'text'}) 
 78          author_name = self.__clean_value(metadata, 'author') 
 79          author = mh.add_element('author') 
 80          mh.add_element('name', content=author_name, parent=author) 
 81           
 82          attr = {u'rel': u'edit', u'type': self.collection.member_media_type, 
 83                  u'href': unicode(escape("%s/%s" % (self.collection.base_edit_uri, 
 84                                                     member_id))),} 
 85          mh.add_element('link', attributes=attr) 
 86           
 87          attr = {u'rel': u'edit-media', u'type': self.media_type,  
 88                  u'href': unicode(escape("%s/%s" % (self.collection.base_media_edit_uri, 
 89                                                     media_id)))} 
 90          link = mh.add_element('link', attributes=attr) 
 91   
 92          attr = {u'src': unicode(escape("%s/%s" % (self.collection.base_uri, media_id))), 
 93                  u'type': self.media_type} 
 94          mh.add_element('content', attributes=attr) 
 95   
 96          self.entry = mh.entry 
 97          del mh 
 98           
 99 -    def __clean_value(self, metadata, name): 
100          value = getattr(metadata, name, None) 
101           
102          if not value: 
103              value = u'' 
104               
105          elif isinstance(value, list): 
106              value = unicode(', '.join(value)) 
107          elif isinstance(value, basetring): 
108              value =  unicode(value) 
109   
110          return value 
111       
112 -    def __get_meta_data(self, source): 
113          parser = None 
114          try: 
115              parser = guessParser(input=StringInputStream(source)) 
116          except InputStreamError, err: 
117              raise unicode(err) 
118          if not parser: 
119              raise "Could not parse '%s'" % filepath 
120   
121          try: 
122              metadata = extractMetadata(parser) 
123          except HachoirError, err: 
124              raise unicode(err) 
125   
126          return metadata 
127