Uaktualnienie README.rst.

[redakcja.git] / apps / api / handlers / library_handlers.py

diff --git a/apps/api/handlers/library_handlers.py b/apps/api/handlers/library_handlers.py
index 0651352..f7d5784 100644 (file)
--- a/apps/api/handlers/library_handlers.py
+++ b/apps/api/handlers/library_handlers.py
@@ -1,4 +1,8 @@
 # -*- encoding: utf-8 -*-
 # -*- encoding: utf-8 -*-

+import os.path
+
+import logging
+log = logging.getLogger('platforma.api.library')

 
 __author__= "Łukasz Rekucki"
 __date__ = "$2009-09-25 15:49:50$"
 
 __author__= "Łukasz Rekucki"
 __date__ = "$2009-09-25 15:49:50$"


@@ -6,23 +10,56 @@ __doc__ = "Module documentation."
 
 from piston.handler import BaseHandler, AnonymousBaseHandler
 
 
 from piston.handler import BaseHandler, AnonymousBaseHandler
 

-
-import settings
-import librarian
-import api.forms as forms
+import re

 from datetime import date
 
 from django.core.urlresolvers import reverse
 from datetime import date
 
 from django.core.urlresolvers import reverse

+from django.utils import simplejson as json
+from django.db import IntegrityError
+
+import librarian
+import librarian.html
+from librarian import dcparser, parser

 
 

-from wlrepo import MercurialLibrary, RevisionNotFound, DocumentAlreadyExists
-from librarian import dcparser
+from wlrepo import *
+from api.models import PullRequest
+from explorer.models import GalleryForDocument

 
 

+# internal imports
+import api.forms as forms

 import api.response as response
 import api.response as response

-from api.utils import validate_form, hglibrary
+from api.utils import validate_form, hglibrary, natural_order
+from api.models import PartCache
+
+#
+import settings
+
+
+def is_prq(username):
+    return username.startswith('$prq-')
+
+def check_user(request, user):
+    log.info("user: %r, perm: %r" % (request.user, request.user.get_all_permissions()) )
+    #pull request
+    if is_prq(user):
+        if not request.user.has_perm('api.pullrequest.can_view'):
+            yield response.AccessDenied().django_response({
+                'reason': 'access-denied',
+                'message': "You don't have enough priviliges to view pull requests."
+            })
+    # other users
+    elif request.user.username != user:
+        if not request.user.has_perm('api.document.can_view_other'):
+            yield response.AccessDenied().django_response({
+                'reason': 'access-denied',
+                'message': "You don't have enough priviliges to view other people's document."
+            })
+    pass

 
 #
 # Document List Handlers
 #
 
 #
 # Document List Handlers
 #

+# TODO: security check

 class BasicLibraryHandler(AnonymousBaseHandler):
     allowed_methods = ('GET',)
 
 class BasicLibraryHandler(AnonymousBaseHandler):
     allowed_methods = ('GET',)
 


@@ -32,10 +69,11 @@ class BasicLibraryHandler(AnonymousBaseHandler):
         document_list = [{
             'url': reverse('document_view', args=[docid]),
             'name': docid } for docid in lib.documents() ]
         document_list = [{
             'url': reverse('document_view', args=[docid]),
             'name': docid } for docid in lib.documents() ]

-

         return {'documents' : document_list}
         
         return {'documents' : document_list}
         

-
+#
+# This handler controlls the document collection
+#

 class LibraryHandler(BaseHandler):
     allowed_methods = ('GET', 'POST')
     anonymous = BasicLibraryHandler
 class LibraryHandler(BaseHandler):
     allowed_methods = ('GET', 'POST')
     anonymous = BasicLibraryHandler


@@ -44,11 +82,39 @@ class LibraryHandler(BaseHandler):
     def read(self, request, lib):
         """Return the list of documents."""
 
     def read(self, request, lib):
         """Return the list of documents."""
 

-        document_list = [{
-            'url': reverse('document_view', args=[docid]),
-            'name': docid } for docid in lib.documents() ]
+        documents = {}
+        
+        for docid in lib.documents():            
+            documents[docid] = {
+                'url': reverse('document_view', args=[docid]),
+                'name': docid,
+                'parts': []
+            }
+
+        parts = PartCache.objects.defer('part_id')\
+            .values_list('part_id', 'document_id').distinct()
+       
+        document_tree = dict(documents)
+
+        for part, docid in parts:
+            # this way, we won't display broken links
+            if not documents.has_key(part):
+                log.info("NOT FOUND: %s", part)
+                continue
+
+            parent = documents[docid]
+            child = documents[part]
+
+            # not top-level anymore
+            document_tree.pop(part)
+            parent['parts'].append(child)
+        
+        for doc in documents.itervalues():
+            doc['parts'].sort(key=natural_order(lambda d: d['name']))
+            
+        return {'documents': sorted(document_tree.itervalues(),
+            key=natural_order(lambda d: d['name']) ) }

 
 

-        return {'documents' : document_list }        

 
     @validate_form(forms.DocumentUploadForm, 'POST')
     @hglibrary
 
     @validate_form(forms.DocumentUploadForm, 'POST')
     @hglibrary


@@ -56,32 +122,55 @@ class LibraryHandler(BaseHandler):
         """Create a new document."""       
 
         if form.cleaned_data['ocr_data']:
         """Create a new document."""       
 
         if form.cleaned_data['ocr_data']:

-            data = form.cleaned_data['ocr_data'].encode('utf-8')
+            data = form.cleaned_data['ocr_data']

         else:            
             data = request.FILES['ocr_file'].read().decode('utf-8')
 
         else:            
             data = request.FILES['ocr_file'].read().decode('utf-8')
 

+        if data is None:
+            return response.BadRequest().django_response('You must pass ocr_data or ocr_file.')
+

         if form.cleaned_data['generate_dc']:
             data = librarian.wrap_text(data, unicode(date.today()))
 
         docid = form.cleaned_data['bookname']
         if form.cleaned_data['generate_dc']:
             data = librarian.wrap_text(data, unicode(date.today()))
 
         docid = form.cleaned_data['bookname']

+

         try:
         try:

-            doc = lib.document_create(docid)
-            doc = doc.quickwrite('xml', data, '$AUTO$ XML data uploaded.',
-                user=request.user.username)
-
-            url = reverse('document_view', args=[doc.id])
-
-            return response.EntityCreated().django_response(\
-                body = {
-                    'url': url,
-                    'name': doc.id,
-                    'revision': doc.revision },
-                url = url )
-                
+            lock = lib.lock()            
+            try:
+                log.info("DOCID %s", docid)
+                doc = lib.document_create(docid)
+                # document created, but no content yet
+
+                try:
+                    doc = doc.quickwrite('xml', data.encode('utf-8'),
+                        '$AUTO$ XML data uploaded.', user=request.user.username)
+                except Exception,e:
+                    import traceback
+                    # rollback branch creation
+                    lib._rollback()
+                    raise LibraryException(traceback.format_exc())
+
+                url = reverse('document_view', args=[doc.id])
+
+                return response.EntityCreated().django_response(\
+                    body = {
+                        'url': url,
+                        'name': doc.id,
+                        'revision': doc.revision },
+                    url = url )            
+            finally:
+                lock.release()
+        except LibraryException, e:
+            import traceback
+            return response.InternalError().django_response({
+                "reason": traceback.format_exc()
+            })

         except DocumentAlreadyExists:
             # Document is already there
         except DocumentAlreadyExists:
             # Document is already there

-            return response.EntityConflict().django_response(\
-                {"reason": "Document %s already exists." % docid})
+            return response.EntityConflict().django_response({
+                "reason": "already-exists",
+                "message": "Document already exists." % docid
+            })

 
 #
 # Document Handlers
 
 #
 # Document Handlers


@@ -98,8 +187,9 @@ class BasicDocumentHandler(AnonymousBaseHandler):
 
         result = {
             'name': doc.id,
 
         result = {
             'name': doc.id,

-            'text_url': reverse('doctext_view', args=[doc.id,doc.revision]),
-            'dc_url': reverse('docdc_view', args=[doc.id,doc.revision]),
+            'html_url': reverse('dochtml_view', args=[doc.id]),
+            'text_url': reverse('doctext_view', args=[doc.id]),
+            'dc_url': reverse('docdc_view', args=[doc.id]),

             'public_revision': doc.revision,
         }
 
             'public_revision': doc.revision,
         }
 


@@ -112,153 +202,509 @@ class DocumentHandler(BaseHandler):
     allowed_methods = ('GET', 'PUT')
     anonymous = BasicDocumentHandler
 
     allowed_methods = ('GET', 'PUT')
     anonymous = BasicDocumentHandler
 

+    @validate_form(forms.DocumentRetrieveForm, 'GET')

     @hglibrary
     @hglibrary

-    def read(self, request, docid, lib):
+    def read(self, request, form, docid, lib):

         """Read document's meta data"""       
         """Read document's meta data"""       

-        try:
-            doc = lib.document(docid)
-            udoc = doc.take(request.user.username)
-        except RevisionNotFound:
-            return request.EnityNotFound().django_response()
-
-        # is_shared = udoc.ancestorof(doc)
-        # is_uptodate = is_shared or shared.ancestorof(document)
+        log.info(u"User '%s' wants to %s(%s) as %s" % \
+            (request.user.username, docid, form.cleaned_data['revision'], form.cleaned_data['user']) )

 
 

-        result = {
-            'name': udoc.id,
-            'text_url': reverse('doctext_view', args=[doc.id,doc.revision]),
-            'dc_url': reverse('docdc_view', args=[doc.id,doc.revision]),
-            'user_revision': udoc.revision,
-            'public_revision': doc.revision,            
-        }       
+        user = form.cleaned_data['user'] or request.user.username
+        rev = form.cleaned_data['revision'] or 'latest'

 
 

-        return result
+        for error in check_user(request, user):
+            return error
+            
+        try:
+            doc = lib.document(docid, user, rev=rev)
+        except RevisionMismatch, e:
+            # the document exists, but the revision is bad
+            return response.EntityNotFound().django_response({
+                'reason': 'revision-mismatch',
+                'message': e.message,
+                'docid': docid,
+                'user': user,
+            })
+        except RevisionNotFound, e:
+            # the user doesn't have this document checked out
+            # or some other weird error occured
+            # try to do the checkout
+            if is_prq(user) or (user == request.user.username):
+                try:
+                    mdoc = lib.document(docid)
+                    doc = mdoc.take(user)
+
+                    if is_prq(user):
+                        # source revision, should probably change
+                        # but there are no changes yet, so...
+                        pass
+                    
+                except RevisionNotFound, e:
+                    return response.EntityNotFound().django_response({
+                        'reason': 'document-not-found',
+                        'message': e.message,
+                        'docid': docid
+                    })
+            else:
+                return response.EntityNotFound().django_response({
+                    'reason': 'document-not-found',
+                    'message': e.message,
+                    'docid': docid,
+                    'user': user,
+                })
+
+        return {
+            'name': doc.id,
+            'user': user,
+            'html_url': reverse('dochtml_view', args=[doc.id]),
+            'text_url': reverse('doctext_view', args=[doc.id]),
+            # 'dc_url': reverse('docdc_view', args=[doc.id]),
+            'gallery_url': reverse('docgallery_view', args=[doc.id]),
+            'merge_url': reverse('docmerge_view', args=[doc.id]),
+            'revision': doc.revision,
+            'timestamp': doc.revision.timestamp,
+            # 'public_revision': doc.revision,
+            # 'public_timestamp': doc.revision.timestamp,
+        }   
+
+    
+#    @hglibrary
+#    def update(self, request, docid, lib):
+#        """Update information about the document, like display not"""
+#        return
+#
+#
+#
+class DocumentHTMLHandler(BaseHandler):
+    allowed_methods = ('GET')

 
 

+    @validate_form(forms.DocumentRetrieveForm, 'GET')

     @hglibrary
     @hglibrary

-    def update(self, request, docid, lib):
-        """Update information about the document, like display not"""
-        return
+    def read(self, request, form, docid, lib, stylesheet='partial'):
+        """Read document as html text"""
+        try:
+            revision = form.cleaned_data['revision']
+            user = form.cleaned_data['user'] or request.user.username
+            document = lib.document_for_rev(revision)
+
+            if document.id != docid:
+                return response.BadRequest().django_response({
+                    'reason': 'name-mismatch',
+                    'message': 'Provided revision is not valid for this document'
+                })
+
+            if document.owner != user:
+                return response.BadRequest().django_response({
+                    'reason': 'user-mismatch',
+                    'message': "Provided revision doesn't belong to user %s" % user
+                })
+
+            for error in check_user(request, user):
+                return error
+
+            return librarian.html.transform(document.data('xml'), is_file=False, \
+                parse_dublincore=False, stylesheet=stylesheet,\
+                options={
+                    "with-paths": 'boolean(1)',                    
+                })
+                
+        except (EntryNotFound, RevisionNotFound), e:
+            return response.EntityNotFound().django_response({
+                'reason': 'not-found', 'message': e.message})
+        except librarian.ParseError, e:
+            return response.InternalError().django_response({
+                'reason': 'xml-parse-error', 'message': e.message })

 
 #
 
 #

-# Document Text View
+# Image Gallery

 #
 #

-class DocumentTextHandler(BaseHandler):
-    allowed_methods = ('GET', 'PUT')

 
 

-    @hglibrary
-    def read(self, request, docid, revision, lib):
-        """Read document as raw text"""               
-        try:
-            if revision == 'latest':
-                document = lib.document(docid)
-            else:
-                document = lib.document_for_rev(revision)
-            
-            # TODO: some finer-grained access control
-            return document.data('xml')
-        except RevisionNotFound:
-            return response.EntityNotFound().django_response()
+class DocumentGalleryHandler(BaseHandler):
+    allowed_methods = ('GET')
+    
+    
+    def read(self, request, docid):
+        """Read meta-data about scans for gallery of this document."""
+        galleries = []
+        from urllib import quote

 
 

-    @hglibrary
-    def update(self, request, docid, revision, lib):
-        try:
-            data = request.PUT['contents']            
+        for assoc in GalleryForDocument.objects.filter(document=docid):
+            dirpath = os.path.join(settings.MEDIA_ROOT, assoc.subpath)

 
 

-            if request.PUT.has_key('message'):
-                msg = u"$USER$ " + request.PUT['message']
-            else:
-                msg = u"$AUTO$ XML content update."
+            if not os.path.isdir(dirpath):
+                log.warn(u"[WARNING]: missing gallery %s", dirpath)
+                continue

 
 

-            current = lib.document(docid, request.user.username)
-            orig = lib.document_for_rev(revision)
+            gallery = {'name': assoc.name, 'pages': []}
+            
+            for file in sorted(os.listdir(dirpath)):
+                if not isinstance(file, unicode):
+                    try:
+                        file = file.decode('utf-8')
+                    except:
+                        log.warn(u"File %r in gallery %r is not unicode. Ommiting."\
+                            % (file, dirpath) )
+                        file = None
+
+                if file is not None:
+                    name, ext = os.path.splitext(os.path.basename(file))
+
+                    if ext.lower() not in [u'.png', u'.jpeg', u'.jpg']:
+                        log.warn(u"Ignoring: %s %s", name, ext)
+                        url = None
+
+                    url = settings.MEDIA_URL + assoc.subpath + u'/' + file
+                
+                if url is None:
+                    url = settings.MEDIA_URL + u'/missing.png'
+                    
+                gallery['pages'].append( quote(url.encode('utf-8')) )

 
 

-            if current != orig:
-                return response.EntityConflict().django_response({
-                        "reason": "out-of-date",
-                        "provided_revision": orig.revision,
-                        "latest_revision": current.revision })
+#            gallery['pages'].sort()
+            galleries.append(gallery)

 
 

-            ndoc = doc.quickwrite('xml', data, msg)
+        return galleries                      

 
 

-            # return the new revision number
-            return {
-                "document": ndoc.id,
-                "subview": "xml",
-                "previous_revision": prev,
-                "updated_revision": ndoc.revision
-            }
-        
-        except (RevisionNotFound, KeyError):
-            return response.EntityNotFound().django_response()
+#
+# Document Text View
+#

 
 

+XINCLUDE_REGEXP = r"""<(?:\w+:)?include\s+[^>]*?href=("|')wlrepo://(?P<link>[^\1]+?)\1\s*[^>]*?>"""

 #
 #

-# Dublin Core handlers

 #
 #

-# @requires librarian

 #
 #

-class DocumentDublinCoreHandler(BaseHandler):
-    allowed_methods = ('GET', 'PUT')

 
 

+class DocumentTextHandler(BaseHandler):
+    allowed_methods = ('GET', 'POST')
+
+    @validate_form(forms.TextRetrieveForm, 'GET')

     @hglibrary
     @hglibrary

-    def read(self, request, docid, revision, lib):
+    def read(self, request, form, docid, lib):

         """Read document as raw text"""        
         try:
         """Read document as raw text"""        
         try:

-            if revision == 'latest':
-                document = lib.document(docid)
-            else:
-                document = lib.document_for_rev(revision)
+            revision = form.cleaned_data['revision']
+            part = form.cleaned_data['part']
+            user = form.cleaned_data['user'] or request.user.username            

             
             

-            bookinfo = dcparser.BookInfo.from_string(doc.data('xml'))
-            return bookinfo.serialize()
-        except RevisionNotFound:
-            return response.EntityNotFound().django_response()
-
+            document = lib.document_for_rev(revision)
+            
+            if document.id != docid:
+                return response.BadRequest().django_response({
+                    'reason': 'name-mismatch',
+                    'message': 'Provided revision is not valid for this document'
+                })
+
+            if document.owner != user:
+                return response.BadRequest().django_response({
+                    'reason': 'user-mismatch',
+                    'message': "Provided revision doesn't belong to user %s" % user
+                })
+
+            for error in check_user(request, user):
+                return error
+            
+            if not part:                
+                return document.data('xml')
+            
+            xdoc = parser.WLDocument.from_string(document.data('xml'),\
+                parse_dublincore=False)
+            ptext = xdoc.part_as_text(part)
+
+            if ptext is None:
+                return response.EntityNotFound().django_response({
+                      'reason': 'no-part-in-document'                     
+                })
+
+            return ptext
+        except librarian.ParseError, e:
+            return response.EntityNotFound().django_response({
+                'reason': 'invalid-document-state',
+                'exception': type(e),
+                'message': e.message
+            })
+        except (EntryNotFound, RevisionNotFound), e:
+            return response.EntityNotFound().django_response({
+                'reason': 'not-found',
+                'exception': type(e), 'message': e.message
+            })   
+
+    @validate_form(forms.TextUpdateForm, 'POST')

     @hglibrary
     @hglibrary

-    def update(self, request, docid, revision, lib):
+    def create(self, request, form, docid, lib):

         try:
         try:

-            bi_json = request.PUT['contents']            
-            if request.PUT.has_key('message'):
-                msg = u"$USER$ " + request.PUT['message']
-            else:
-                msg = u"$AUTO$ Dublin core update."
+            revision = form.cleaned_data['revision']
+            msg = form.cleaned_data['message']
+            user = form.cleaned_data['user'] or request.user.username

 
 

-            current = lib.document(docid, request.user.username)
+            # do not allow changing not owned documents
+            # (for now... )
+            
+            
+            if user != request.user.username:
+                return response.AccessDenied().django_response({
+                    'reason': 'insufficient-priviliges',
+                })
+            
+            current = lib.document(docid, user)

             orig = lib.document_for_rev(revision)
 
             if current != orig:
                 return response.EntityConflict().django_response({
                         "reason": "out-of-date",
             orig = lib.document_for_rev(revision)
 
             if current != orig:
                 return response.EntityConflict().django_response({
                         "reason": "out-of-date",

-                        "provided": orig.revision,
-                        "latest": current.revision })
-
-            xmldoc = parser.WLDocument.from_string(current.data('xml'))
-            document.book_info = dcparser.BookInfo.from_json(bi_json)
-
-            # zapisz
-            ndoc = current.quickwrite('xml', \
-                document.serialize().encode('utf-8'),\
-                message=msg, user=request.user.username)
-
-            return {
-                "document": ndoc.id,
-                "subview": "xml",
-                "previous_revision": prev,
-                "updated_revision": ndoc.revision
-            }
-        except (RevisionNotFound, KeyError):
-            return response.EntityNotFound().django_response()
+                        "provided_revision": orig.revision,
+                        "latest_revision": current.revision })
+            
+            if form.cleaned_data.has_key('contents'):
+                data = form.cleaned_data['contents']
+            else:                               
+                chunks = form.cleaned_data['chunks']
+                xdoc = parser.WLDocument.from_string(current.data('xml'))
+                errors = xdoc.merge_chunks(chunks)
+
+                if len(errors):
+                    return response.EntityConflict().django_response({
+                            "reason": "invalid-chunks",
+                            "message": "Unable to merge following parts into the document: %s " % ",".join(errors)
+                    })
+
+                data = xdoc.serialize()
+
+            # try to find any Xinclude tags
+            includes = [m.groupdict()['link'] for m in (re.finditer(\
+                XINCLUDE_REGEXP, data, flags=re.UNICODE) or []) ]
+
+            log.info("INCLUDES: %s", includes)
+
+            # TODO: provide useful routines to make this simpler
+            def xml_update_action(lib, resolve):
+                try:
+                    f = lib._fileopen(resolve('parts'), 'r')
+                    stored_includes = json.loads(f.read())
+                    f.close()
+                except:
+                    stored_includes = []
+                
+                if stored_includes != includes:
+                    f = lib._fileopen(resolve('parts'), 'w+')
+                    f.write(json.dumps(includes))
+                    f.close()
+
+                    lib._fileadd(resolve('parts'))
+
+                    # update the parts cache
+                    PartCache.update_cache(docid, current.owner,\
+                        stored_includes, includes)
+
+                # now that the parts are ok, write xml
+                f = lib._fileopen(resolve('xml'), 'w+')
+                f.write(data.encode('utf-8'))
+                f.close()
+
+            ndoc = None
+            ndoc = current.invoke_and_commit(\
+                xml_update_action, lambda d: (msg, user) )
+
+            try:
+                # return the new revision number
+                return response.SuccessAllOk().django_response({
+                    "document": ndoc.id,
+                    "user": user,
+                    "subview": "xml",
+                    "previous_revision": current.revision,
+                    "revision": ndoc.revision,
+                    'timestamp': ndoc.revision.timestamp,
+                    "url": reverse("doctext_view", args=[ndoc.id])
+                })
+            except Exception, e:
+                if ndoc: lib._rollback()
+                raise e        
+        except RevisionNotFound, e:
+            return response.EntityNotFound(mimetype="text/plain").\
+                django_response(e.message)
+

 
 

+#
+# Dublin Core handlers
+#
+# @requires librarian
+#
+#class DocumentDublinCoreHandler(BaseHandler):
+#    allowed_methods = ('GET', 'POST')
+#
+#    @hglibrary
+#    def read(self, request, docid, lib):
+#        """Read document as raw text"""
+#        try:
+#            revision = request.GET.get('revision', 'latest')
+#
+#            if revision == 'latest':
+#                doc = lib.document(docid)
+#            else:
+#                doc = lib.document_for_rev(revision)
+#
+#
+#            if document.id != docid:
+#                return response.BadRequest().django_response({'reason': 'name-mismatch',
+#                    'message': 'Provided revision is not valid for this document'})
+#
+#            bookinfo = dcparser.BookInfo.from_string(doc.data('xml'))
+#            return bookinfo.serialize()
+#        except (EntryNotFound, RevisionNotFound), e:
+#            return response.EntityNotFound().django_response({
+#                'exception': type(e), 'message': e.message})
+#
+#    @hglibrary
+#    def create(self, request, docid, lib):
+#        try:
+#            bi_json = request.POST['contents']
+#            revision = request.POST['revision']
+#
+#            if request.POST.has_key('message'):
+#                msg = u"$USER$ " + request.PUT['message']
+#            else:
+#                msg = u"$AUTO$ Dublin core update."
+#
+#            current = lib.document(docid, request.user.username)
+#            orig = lib.document_for_rev(revision)
+#
+#            if current != orig:
+#                return response.EntityConflict().django_response({
+#                        "reason": "out-of-date",
+#                        "provided": orig.revision,
+#                        "latest": current.revision })
+#
+#            xmldoc = parser.WLDocument.from_string(current.data('xml'))
+#            document.book_info = dcparser.BookInfo.from_json(bi_json)
+#
+#            # zapisz
+#            ndoc = current.quickwrite('xml', \
+#                document.serialize().encode('utf-8'),\
+#                message=msg, user=request.user.username)
+#
+#            try:
+#                # return the new revision number
+#                return {
+#                    "document": ndoc.id,
+#                    "subview": "dc",
+#                    "previous_revision": current.revision,
+#                    "revision": ndoc.revision,
+#                    'timestamp': ndoc.revision.timestamp,
+#                    "url": reverse("docdc_view", args=[ndoc.id])
+#                }
+#            except Exception, e:
+#                if ndoc: lib._rollback()
+#                raise e
+#        except RevisionNotFound:
+#            return response.EntityNotFound().django_response()

 
 class MergeHandler(BaseHandler):
     allowed_methods = ('POST',)
 
 
 class MergeHandler(BaseHandler):
     allowed_methods = ('POST',)
 

-    @validate_form(forms.MergeRequestForm)
+    @validate_form(forms.MergeRequestForm, 'POST')

     @hglibrary
     def create(self, request, form, docid, lib):
         """Create a new document revision from the information provided by user"""
     @hglibrary
     def create(self, request, form, docid, lib):
         """Create a new document revision from the information provided by user"""

+        revision = form.cleaned_data['revision']
+
+        # fetch the main branch document
+        doc = lib.document(docid)
+
+        # fetch the base document
+        user_doc = lib.document_for_rev(revision)
+        base_doc = user_doc.latest()
+
+        if base_doc != user_doc:
+            return response.EntityConflict().django_response({
+                "reason": "out-of-date",
+                "provided": str(user_doc.revision),
+                "latest": str(base_doc.revision)
+            })      
+
+        if form.cleaned_data['type'] == 'update':
+            # update is always performed from the file branch
+            # to the user branch
+            changed, clean = base_doc.update(request.user.username)
+
+            # update user document
+            if changed:
+                user_doc_new = user_doc.latest()
+            else:
+                user_doc_new = user_doc
+                
+            # shared document is the same
+            doc_new = doc
+
+        if form.cleaned_data['type'] == 'share':
+            if not base_doc.up_to_date():
+                return response.BadRequest().django_response({
+                    "reason": "not-fast-forward",
+                    "message": "You must first update yout branch to the latest version."
+                })
+
+            # check for unresolved conflicts            
+            if base_doc.has_conflict_marks():
+                return response.BadRequest().django_response({
+                    "reason": "unresolved-conflicts",
+                    "message": "There are unresolved conflicts in your file. Fix them, and try again."
+                })
+
+            if not request.user.has_perm('api.document.can_share'):
+                # User is not permitted to make a merge, right away
+                # So we instead create a pull request in the database
+                try:
+                    prq, created = PullRequest.objects.get_or_create(
+                        comitter = request.user,
+                        document = docid,
+                        status = "N",
+                        defaults = {
+                            'source_revision': str(base_doc.revision),
+                            'comment': form.cleaned_data['message'] or '$AUTO$ Document shared.',
+                        }
+                    )
+
+                    # there can't be 2 pending request from same user
+                    # for the same document
+                    if not created:
+                        prq.source_revision = str(base_doc.revision)
+                        prq.comment = prq.comment + 'u\n\n' + (form.cleaned_data['message'] or u'')
+                        prq.save()
+
+                    return response.RequestAccepted().django_response(\
+                        ticket_status=prq.status, \
+                        ticket_uri=reverse("pullrequest_view", args=[prq.id]) )
+                except IntegrityError:
+                    return response.EntityConflict().django_response({
+                        'reason': 'request-already-exist'
+                    })
+
+            changed = base_doc.share(form.cleaned_data['message'])
+
+            # update shared version if needed
+            if changed:
+                doc_new = doc.latest()
+            else:
+                doc_new = doc

 
 

-        pass
+            # the user wersion is the same
+            user_doc_new = base_doc

 
 

+        # The client can compare parent_revision to revision
+        # to see if he needs to update user's view        
+        # Same goes for shared view

         
         

-        
-        
+        return response.SuccessAllOk().django_response({
+            "name": user_doc_new.id,
+            "user": user_doc_new.owner,
+
+            "revision": user_doc_new.revision,
+            'timestamp': user_doc_new.revision.timestamp,
+
+            "parent_revision": user_doc_new.revision,
+            "parent_timestamp": user_doc_new.revision.timestamp,
+
+            "shared_revision": doc_new.revision,
+            "shared_timestamp": doc_new.revision.timestamp,
+
+            "shared_parent_revision": doc.revision,
+            "shared_parent_timestamp": doc.revision.timestamp,
+        })
\ No newline at end of file