diff -r 058bb3dc685f -r 0b59724cb3f2 cubicweb/entities/adapters.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cubicweb/entities/adapters.py	Sat Jan 16 13:48:51 2016 +0100
@@ -0,0 +1,427 @@
+# copyright 2010-2015 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
+#
+# This file is part of CubicWeb.
+#
+# CubicWeb is free software: you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 2.1 of the License, or (at your option)
+# any later version.
+#
+# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
+"""some basic entity adapter implementations, for interfaces used in the
+framework itself.
+"""
+from cubicweb import _
+
+from itertools import chain
+from hashlib import md5
+
+from logilab.mtconverter import TransformError
+from logilab.common.decorators import cached
+
+from cubicweb import ValidationError, view, ViolatedConstraint, UniqueTogetherError
+from cubicweb.predicates import is_instance, relation_possible, match_exception
+
+
+class IEmailableAdapter(view.EntityAdapter):
+    __regid__ = 'IEmailable'
+    __select__ = relation_possible('primary_email') | relation_possible('use_email')
+
+    def get_email(self):
+        if getattr(self.entity, 'primary_email', None):
+            return self.entity.primary_email[0].address
+        if getattr(self.entity, 'use_email', None):
+            return self.entity.use_email[0].address
+        return None
+
+    def allowed_massmail_keys(self):
+        """returns a set of allowed email substitution keys
+
+        The default is to return the entity's attribute list but you might
+        override this method to allow extra keys.  For instance, a Person
+        class might want to return a `companyname` key.
+        """
+        return set(rschema.type
+                   for rschema, attrtype in self.entity.e_schema.attribute_definitions()
+                   if attrtype.type not in ('Password', 'Bytes'))
+
+    def as_email_context(self):
+        """returns the dictionary as used by the sendmail controller to
+        build email bodies.
+
+        NOTE: the dictionary keys should match the list returned by the
+        `allowed_massmail_keys` method.
+        """
+        return dict((attr, getattr(self.entity, attr))
+                    for attr in self.allowed_massmail_keys())
+
+
+class INotifiableAdapter(view.EntityAdapter):
+    __regid__ = 'INotifiable'
+    __select__ = is_instance('Any')
+
+    def notification_references(self, view):
+        """used to control References field of email send on notification
+        for this entity. `view` is the notification view.
+
+        Should return a list of eids which can be used to generate message
+        identifiers of previously sent email(s)
+        """
+        itree = self.entity.cw_adapt_to('ITree')
+        if itree is not None:
+            return itree.path()[:-1]
+        if view.msgid_timestamp:
+            return (self.entity.eid,)
+        return ()
+
+
+class IFTIndexableAdapter(view.EntityAdapter):
+    """standard adapter to handle fulltext indexing
+
+    .. automethod:: cubicweb.entities.adapters.IFTIndexableAdapter.fti_containers
+    .. automethod:: cubicweb.entities.adapters.IFTIndexableAdapter.get_words
+    """
+    __regid__ = 'IFTIndexable'
+    __select__ = is_instance('Any')
+
+    def fti_containers(self, _done=None):
+        """return the list of entities to index when handling ``self.entity``
+
+        The actual list of entities depends on ``fulltext_container`` usage
+        in the datamodel definition
+        """
+        if _done is None:
+            _done = set()
+        entity = self.entity
+        _done.add(entity.eid)
+        containers = tuple(entity.e_schema.fulltext_containers())
+        if containers:
+            for rschema, role in containers:
+                if role == 'object':
+                    targets = getattr(entity, rschema.type)
+                else:
+                    targets = getattr(entity, 'reverse_%s' % rschema)
+                for target in targets:
+                    if target.eid in _done:
+                        continue
+                    for container in target.cw_adapt_to('IFTIndexable').fti_containers(_done):
+                        yield container
+        else:
+            yield entity
+
+    # weight in ABCD
+    entity_weight = 1.0
+    attr_weight = {}
+
+    def get_words(self):
+        """used by the full text indexer to get words to index
+
+        this method should only be used on the repository side since it depends
+        on the logilab.database package
+
+        :rtype: list
+        :return: the list of indexable word of this entity
+        """
+        from logilab.database.fti import tokenize
+        # take care to cases where we're modyfying the schema
+        entity = self.entity
+        pending = self._cw.transaction_data.setdefault('pendingrdefs', set())
+        words = {}
+        for rschema in entity.e_schema.indexable_attributes():
+            if (entity.e_schema, rschema) in pending:
+                continue
+            weight = self.attr_weight.get(rschema, 'C')
+            try:
+                value = entity.printable_value(rschema, format=u'text/plain')
+            except TransformError:
+                continue
+            except Exception:
+                self.exception("can't add value of %s to text index for entity %s",
+                               rschema, entity.eid)
+                continue
+            if value:
+                words.setdefault(weight, []).extend(tokenize(value))
+        for rschema, role in entity.e_schema.fulltext_relations():
+            if role == 'subject':
+                for entity_ in getattr(entity, rschema.type):
+                    merge_weight_dict(words, entity_.cw_adapt_to('IFTIndexable').get_words())
+            else:  # if role == 'object':
+                for entity_ in getattr(entity, 'reverse_%s' % rschema.type):
+                    merge_weight_dict(words, entity_.cw_adapt_to('IFTIndexable').get_words())
+        return words
+
+
+def merge_weight_dict(maindict, newdict):
+    for weight, words in newdict.items():
+        maindict.setdefault(weight, []).extend(words)
+
+
+class IDownloadableAdapter(view.EntityAdapter):
+    """interface for downloadable entities"""
+    __regid__ = 'IDownloadable'
+    __abstract__ = True
+
+    def download_url(self, **kwargs):  # XXX not really part of this interface
+        """return a URL to download entity's content
+
+        It should be a unicode object containing url-encoded ASCII.
+        """
+        raise NotImplementedError
+
+    def download_content_type(self):
+        """return MIME type (unicode) of the downloadable content"""
+        raise NotImplementedError
+
+    def download_encoding(self):
+        """return encoding (unicode) of the downloadable content"""
+        raise NotImplementedError
+
+    def download_file_name(self):
+        """return file name (unicode) of the downloadable content"""
+        raise NotImplementedError
+
+    def download_data(self):
+        """return actual data (bytes) of the downloadable content"""
+        raise NotImplementedError
+
+
+# XXX should propose to use two different relations for children/parent
+class ITreeAdapter(view.EntityAdapter):
+    """This adapter provides a tree interface.
+
+    It has to be overriden to be configured using the tree_relation,
+    child_role and parent_role class attributes to benefit from this default
+    implementation.
+
+    This class provides the following methods:
+
+    .. automethod: iterparents
+    .. automethod: iterchildren
+    .. automethod: prefixiter
+
+    .. automethod: is_leaf
+    .. automethod: is_root
+
+    .. automethod: root
+    .. automethod: parent
+    .. automethod: children
+    .. automethod: different_type_children
+    .. automethod: same_type_children
+    .. automethod: children_rql
+    .. automethod: path
+    """
+    __regid__ = 'ITree'
+    __abstract__ = True
+
+    child_role = 'subject'
+    parent_role = 'object'
+
+    def children_rql(self):
+        """Returns RQL to get the children of the entity."""
+        return self.entity.cw_related_rql(self.tree_relation, self.parent_role)
+
+    def different_type_children(self, entities=True):
+        """Return children entities of different type as this entity.
+
+        According to the `entities` parameter, return entity objects or the
+        equivalent result set.
+        """
+        res = self.entity.related(self.tree_relation, self.parent_role,
+                                  entities=entities)
+        eschema = self.entity.e_schema
+        if entities:
+            return [e for e in res if e.e_schema != eschema]
+        return res.filtered_rset(lambda x: x.e_schema != eschema, self.entity.cw_col)
+
+    def same_type_children(self, entities=True):
+        """Return children entities of the same type as this entity.
+
+        According to the `entities` parameter, return entity objects or the
+        equivalent result set.
+        """
+        res = self.entity.related(self.tree_relation, self.parent_role,
+                                  entities=entities)
+        eschema = self.entity.e_schema
+        if entities:
+            return [e for e in res if e.e_schema == eschema]
+        return res.filtered_rset(lambda x: x.e_schema is eschema, self.entity.cw_col)
+
+    def is_leaf(self):
+        """Returns True if the entity does not have any children."""
+        return len(self.children()) == 0
+
+    def is_root(self):
+        """Returns true if the entity is root of the tree (e.g. has no parent).
+        """
+        return self.parent() is None
+
+    def root(self):
+        """Return the root entity of the tree."""
+        return self._cw.entity_from_eid(self.path()[0])
+
+    def parent(self):
+        """Returns the parent entity if any, else None (e.g. if we are on the
+        root).
+        """
+        try:
+            return self.entity.related(self.tree_relation, self.child_role,
+                                       entities=True)[0]
+        except (KeyError, IndexError):
+            return None
+
+    def children(self, entities=True, sametype=False):
+        """Return children entities.
+
+        According to the `entities` parameter, return entity objects or the
+        equivalent result set.
+        """
+        if sametype:
+            return self.same_type_children(entities)
+        else:
+            return self.entity.related(self.tree_relation, self.parent_role,
+                                       entities=entities)
+
+    def iterparents(self, strict=True):
+        """Return an iterator on the parents of the entity."""
+        def _uptoroot(self):
+            curr = self
+            while True:
+                curr = curr.parent()
+                if curr is None:
+                    break
+                yield curr
+                curr = curr.cw_adapt_to('ITree')
+        if not strict:
+            return chain([self.entity], _uptoroot(self))
+        return _uptoroot(self)
+
+    def iterchildren(self, _done=None):
+        """Return an iterator over the item's children."""
+        if _done is None:
+            _done = set()
+        for child in self.children():
+            if child.eid in _done:
+                self.error('loop in %s tree: %s', child.cw_etype.lower(), child)
+                continue
+            yield child
+            _done.add(child.eid)
+
+    def prefixiter(self, _done=None):
+        """Return an iterator over the item's descendants in a prefixed order."""
+        if _done is None:
+            _done = set()
+        if self.entity.eid in _done:
+            return
+        _done.add(self.entity.eid)
+        yield self.entity
+        for child in self.same_type_children():
+            for entity in child.cw_adapt_to('ITree').prefixiter(_done):
+                yield entity
+
+    @cached
+    def path(self):
+        """Returns the list of eids from the root object to this object."""
+        path = []
+        adapter = self
+        entity = adapter.entity
+        while entity is not None:
+            if entity.eid in path:
+                self.error('loop in %s tree: %s', entity.cw_etype.lower(), entity)
+                break
+            path.append(entity.eid)
+            try:
+                # check we are not jumping to another tree
+                if (adapter.tree_relation != self.tree_relation or
+                        adapter.child_role != self.child_role):
+                    break
+                entity = adapter.parent()
+                adapter = entity.cw_adapt_to('ITree')
+            except AttributeError:
+                break
+        path.reverse()
+        return path
+
+
+class ISerializableAdapter(view.EntityAdapter):
+    """Adapter to serialize an entity to a bare python structure that may be
+    directly serialized to e.g. JSON.
+    """
+
+    __regid__ = 'ISerializable'
+    __select__ = is_instance('Any')
+
+    def serialize(self):
+        entity = self.entity
+        entity.complete()
+        data = {
+            'cw_etype': entity.cw_etype,
+            'cw_source': entity.cw_metainformation()['source']['uri'],
+            'eid': entity.eid,
+        }
+        for rschema, __ in entity.e_schema.attribute_definitions():
+            attr = rschema.type
+            try:
+                value = entity.cw_attr_cache[attr]
+            except KeyError:
+                # Bytes
+                continue
+            data[attr] = value
+        return data
+
+
+# error handling adapters ######################################################
+
+
+class IUserFriendlyError(view.EntityAdapter):
+    __regid__ = 'IUserFriendlyError'
+    __abstract__ = True
+
+    def __init__(self, *args, **kwargs):
+        self.exc = kwargs.pop('exc')
+        super(IUserFriendlyError, self).__init__(*args, **kwargs)
+
+
+class IUserFriendlyUniqueTogether(IUserFriendlyError):
+    __select__ = match_exception(UniqueTogetherError)
+
+    def raise_user_exception(self):
+        rtypes = self.exc.rtypes
+        errors = {}
+        msgargs = {}
+        i18nvalues = []
+        for rtype in rtypes:
+            errors[rtype] = _('%(KEY-rtype)s is part of violated unicity constraint')
+            msgargs[rtype + '-rtype'] = rtype
+            i18nvalues.append(rtype + '-rtype')
+        errors[''] = _('some relations violate a unicity constraint')
+        raise ValidationError(self.entity.eid, errors, msgargs=msgargs, i18nvalues=i18nvalues)
+
+
+class IUserFriendlyCheckConstraint(IUserFriendlyError):
+    __select__ = match_exception(ViolatedConstraint)
+
+    def raise_user_exception(self):
+        cstrname = self.exc.cstrname
+        eschema = self.entity.e_schema
+        for rschema, attrschema in eschema.attribute_definitions():
+            rdef = rschema.rdef(eschema, attrschema)
+            for constraint in rdef.constraints:
+                if cstrname == 'cstr' + md5(
+                        (eschema.type + rschema.type + constraint.type() +
+                         (constraint.serialize() or '')).encode('ascii')).hexdigest():
+                    break
+            else:
+                continue
+            break
+        else:
+            assert 0
+        key = rschema.type + '-subject'
+        msg, args = constraint.failed_message(key, self.entity.cw_edited[rschema.type])
+        raise ValidationError(self.entity.eid, {key: msg}, args)