source: MILK/trunk/milk_server/milk_server/controllers/trackback/trackback.py @ 5076

'''
 Class representing the pylons controller for trackback functionality.  This allows:
 
 i) commenting on metadata
 ii) referencing of metadata

 NB, info on TrackBack available from:
 
 http://www.sixapart.com/pronet/docs/trackback_spec
 
 @author: C Byrom, Tessella Feb 2009
'''
from milk_server.lib.base import *
from milk_server.models.ndgdoc import NDGDoc 
from ndg.common.src.models.ndgObject import ndgObject
import ndg.common.src.clients.xmldb.eXist.dbconstants as dc
from ndg.common.src.lib.mailer import mailHandler

class TrackbackController(BaseController):
    ''' 
    Provides the pylons controller for recieving trackbacks to NDG documents 
    '''
    def __setup(self,uri):
        ''' 
        Common setup stuff for all the actions on this controller
        @param uri: ndgURI associated with current doc being viewed 
        '''
        logging.info("Setting up TrackbackController")
        self.cf = request.environ['ndgConfig']
        try:
            self.uri=ndgObject(uri, config = self.cf)
        except ValueError,e:
            return e

        self.inputs = request.params

        self.ndgDoc = NDGDoc(ndgURI = uri, config = self.cf)
        logging.info("TrackbackController set up")
        return 0    


    def ping(self, uri):
        ''' 
        This is the default trackback receipt method. When a doc is referenced
        from a TrackBack enabled site, this method should be invoked, via a 
        TrackBack ping, to notify that it has been referenced.  Log the reference
        by sending a mail to the trackback recipient set in the config file and
        adding an entry to the citation feed.
        ( Note we haven't implemented whitelisting yet ) 
        @param uri: ndgURI associated with the doc being pinged by trackback
        '''
        logging.info("Trackback ping called - notifying trackback recipient + feed of citation")
        err = 0
        status=self.__setup(uri)
        
        # lookup referenced doc - to ensure it exists and get extra info to add
        # to citation messages
        self.ndgDoc.setupDocumentModel()
        payload = ""
        if self.ndgDoc.status:
            payload = '<trackback><uri>%s</uri><title>%s</title></trackback>' %(self.ndgDoc.docModel.atomBrowseURL, 
                                                                                self.ndgDoc.name)
        else:
            err = "Could not find document, '%s', to reference in trackback" %uri
        
        server = self.cf.get('DEFAULT', 'mailserver')
        if server is None:
            err = 'Server not configured for trackback (no mail server)'
        
        recipient=self.cf.get('DEFAULT', 'tbrecipient')
        if recipient is None:
            err = 'Server not configured for trackback (no recipient)'
        
        body='Citation Trackback for %s\n\n\n%s'% (uri, payload)
        name='CitationTrackbackFor_%s.xml'%uri
        
        if err != 0:
            c.message = err
            c.err = 1
        else: 
            logging.info("Sending notification mail to '%s'" %recipient)
            status, message = mailHandler([recipient,], body, body,
                                          xmlAttachments = [(payload, name),],
                                          server = server)
            if status:
                c.err = 0
            else:
                c.err = 1
                c.message = 'Unable to forward trackback to designated recipient [%s]' %message

            # lastly, add to citation feed
            logging.info("Mail sent - now add data to the citations feed")
            g.validator._atomClient.feedClient.createGenericFeedEntry(name, payload,
                                                                      dc.CITATIONS_COLLECTION_PATH)
        
        response.headers['content-type'] = 'text/xml'

        logging.info("Trackback logged - now sending receipt")
        return render('genshi', 'trackback/trackback',format='xml')
    

    def getTrackBackInfo(self, uri, name):
        ''' 
        Get the trackback info for the specified uri and name 
        @param uri: ndgURI representing doc
        @param name: title of doc
        @return rdf element representing trackback info
        '''
        s='''<!--
        <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
             xmlns:dc="http://purl.org/dc/elements/1.1/"
             xmlns:trackback="http://madskills.com/public/xml/rss/module/trackback/">
        <rdf:Description
            rdf:about="%s"
            dc:identifier="%s"
            dc:title="%s"
            trackback:ping="%s" />
        </rdf:RDF>
        -->'''%(uri,g.server+h.url_for(),name,
                g.server+h.url_for(controller="trackback/trackback", action="ping"))
        return s


    
    def askCorrect(self,uri):
        ''' 
        Provide a form (ajaxaciously) so that a user can correct a metadata record
        '''
        logging.info("Called askCorrect - to render a corrections input form")
        status=self.__setup(uri)
        c.uri=self.uri
        
        if status:
            return response.write(status)

        try:
            html =  render("genshi", 'trackback/correct',fragment=True)
        except Exception, e:
            logging.error("Error experienced whilst rendering 'correct' template: %s" %e)
            
        logging.info("- retrieved info - now rendering form")
        return html

    
    def correct(self, uri):
        ''' 
        Receive a correction form to update a record and post it to the holder 
        '''
        logging.info("Submitting correction info - this will be mailed to metadata " + \
            "maintainer + added to the corrections feed")
        status=self.__setup(uri)
        if 'ndgSec' not in session:
            c.xml = 'Error - user not currently logged in.  Please login before submitting user comments.'
            logging.error(c.xml)
            return render('kid', 'error')
        
        body = 'Metadata Change Request for %s' %uri
        payload = '<Change><uri>%s</uri><from>%s</from><Contents>%s</Contents></Change>' \
            %(self.inputs['Identifier'],self.inputs['Submitter'],self.inputs['Comment'])
        name = 'ChangeRequestFor_%s.xml' %uri
        maintainer = self.cf.get('DEFAULT','metadataMaintainer')
        
        logging.info("Mailing corrections info to %s" %maintainer)
        status,message = mailHandler([maintainer,],
                                     body,body,xmlAttachments=[(payload,name),],
                                     server=self.cf.get('DEFAULT','mailserver'))
        if status:
            result = 'Your comments have been sent to the metadata maintainer and added to corrections feed for the metatadata database.'
        else:
            result = message
            
        c.xml = result
        logging.info("- now add these to the corrections feed")
        # add the maintainer info
        body += " - for metadata maintainer, '%s'" %maintainer 
        g.validator._atomClient.feedClient.createGenericFeedEntry(body, payload,
                                                                  dc.CORRECTIONS_COLLECTION_PATH)

        g.correctionPosted = result 
        h.redirect_to(h.url_for(controller = 'browse/retrieve', action='view', \
                                uri = uri))