req.py
changeset 2792 135580d15d42
child 2796 14d2c69e12c4
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/req.py	Thu Aug 13 09:30:03 2009 +0200
@@ -0,0 +1,251 @@
+"""Base class for request/session
+
+:organization: Logilab
+:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
+:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
+:license: Library General Public License version 2 - http://www.gnu.org/licenses
+"""
+__docformat__ = "restructuredtext en"
+
+from datetime import time
+
+from logilab.common.decorators import cached
+
+from cubicweb import Unauthorized, typed_eid
+from cubicweb.rset import ResultSet
+from cubicweb.utils import ustrftime, strptime, todate, todatetime
+
+class RequestSessionBase(object):
+    """base class containing stuff shared by server session and web request
+    """
+    def __init__(self, vreg):
+        self.vreg = vreg
+        try:
+            encoding = vreg.property_value('ui.encoding')
+        except: # no vreg or property not registered
+            encoding = 'utf-8'
+        self.encoding = encoding
+        # cache result of execution for (rql expr / eids),
+        # should be emptied on commit/rollback of the server session / web
+        # connection
+        self.local_perm_cache = {}
+        self._ = unicode
+
+    def property_value(self, key):
+        """return value of the property with the given key, giving priority to
+        user specific value if any, else using site value
+        """
+        if self.user:
+            return self.user.property_value(key)
+        return self.vreg.property_value(key)
+
+    def etype_rset(self, etype, size=1):
+        """return a fake result set for a particular entity type"""
+        rset = ResultSet([('A',)]*size, '%s X' % etype,
+                         description=[(etype,)]*size)
+        def get_entity(row, col=0, etype=etype, req=self, rset=rset):
+            return req.vreg.etype_class(etype)(req, rset, row, col)
+        rset.get_entity = get_entity
+        return self.decorate_rset(rset)
+
+    def eid_rset(self, eid, etype=None):
+        """return a result set for the given eid without doing actual query
+        (we have the eid, we can suppose it exists and user has access to the
+        entity)
+        """
+        eid = typed_eid(eid)
+        if etype is None:
+            etype = self.describe(eid)[0]
+        rset = ResultSet([(eid,)], 'Any X WHERE X eid %(x)s', {'x': eid},
+                         [(etype,)])
+        return self.decorate_rset(rset)
+
+    def empty_rset(self):
+        """return a result set for the given eid without doing actual query
+        (we have the eid, we can suppose it exists and user has access to the
+        entity)
+        """
+        return self.decorate_rset(ResultSet([], 'Any X WHERE X eid -1'))
+
+    def entity_from_eid(self, eid, etype=None):
+        """return an entity instance for the given eid. No query is done"""
+        try:
+            return self.entity_cache(eid)
+        except KeyError:
+            rset = self.eid_rset(eid, etype)
+            entity = rset.get_entity(0, 0)
+            self.set_entity_cache(entity)
+            return entity
+
+    def entity_cache(self, eid):
+        raise KeyError
+
+    def set_entity_cache(self, entity):
+        pass
+
+    def ensure_ro_rql(self, rql):
+        """raise an exception if the given rql is not a select query"""
+        first = rql.split(' ', 1)[0].lower()
+        if first in ('insert', 'set', 'delete'):
+            raise Unauthorized(self._('only select queries are authorized'))
+
+    # url generation methods ##################################################
+
+    def build_url(self, *args, **kwargs):
+        """return an absolute URL using params dictionary key/values as URL
+        parameters. Values are automatically URL quoted, and the
+        publishing method to use may be specified or will be guessed.
+        """
+        # use *args since we don't want first argument to be "anonymous" to
+        # avoid potential clash with kwargs
+        assert len(args) == 1, 'only 0 or 1 non-named-argument expected'
+        method = args[0]
+        base_url = kwargs.pop('base_url', None)
+        if base_url is None:
+            base_url = self.base_url()
+        if '_restpath' in kwargs:
+            assert method == 'view', method
+            path = kwargs.pop('_restpath')
+        else:
+            path = method
+        if not kwargs:
+            return u'%s%s' % (base_url, path)
+        return u'%s%s?%s' % (base_url, path, self.build_url_params(**kwargs))
+
+
+    def build_url_params(self, **kwargs):
+        """return encoded params to incorporate them in an URL"""
+        args = []
+        for param, values in kwargs.items():
+            if not isinstance(values, (list, tuple)):
+                values = (values,)
+            for value in values:
+                args.append(u'%s=%s' % (param, self.url_quote(value)))
+        return '&'.join(args)
+
+    def url_quote(self, value, safe=''):
+        """urllib.quote is not unicode safe, use this method to do the
+        necessary encoding / decoding. Also it's designed to quote each
+        part of a url path and so the '/' character will be encoded as well.
+        """
+        if isinstance(value, unicode):
+            quoted = urlquote(value.encode(self.encoding), safe=safe)
+            return unicode(quoted, self.encoding)
+        return urlquote(str(value), safe=safe)
+
+    def url_unquote(self, quoted):
+        """returns a unicode unquoted string
+
+        decoding is based on `self.encoding` which is the encoding
+        used in `url_quote`
+        """
+        if isinstance(quoted, unicode):
+            quoted = quoted.encode(self.encoding)
+        try:
+            return unicode(urlunquote(quoted), self.encoding)
+        except UnicodeDecodeError: # might occurs on manually typed URLs
+            return unicode(urlunquote(quoted), 'iso-8859-1')
+
+    # bound user related methods ###############################################
+
+    @cached
+    def user_data(self):
+        """returns a dictionnary with this user's information"""
+        userinfo = {}
+        if self.is_internal_session:
+            userinfo['login'] = "cubicweb"
+            userinfo['name'] = "cubicweb"
+            userinfo['email'] = ""
+            return userinfo
+        user = self.actual_session().user
+        rql = "Any F,S,A where U eid %(x)s, U firstname F, U surname S, U primary_email E, E address A"
+        try:
+            firstname, lastname, email = self.execute(rql, {'x': user.eid}, 'x')[0]
+            if firstname is None and lastname is None:
+                userinfo['name'] = ''
+            else:
+                userinfo['name'] = ("%s %s" % (firstname, lastname))
+            userinfo['email'] = email
+        except IndexError:
+            userinfo['name'] = None
+            userinfo['email'] = None
+        userinfo['login'] = user.login
+        return userinfo
+
+    def is_internal_session(self):
+        """overrided on the server-side"""
+        return False
+
+    # formating methods #######################################################
+
+    def format_date(self, date, date_format=None, time=False):
+        """return a string for a date time according to instance's
+        configuration
+        """
+        if date:
+            if date_format is None:
+                if time:
+                    date_format = self.property_value('ui.datetime-format')
+                else:
+                    date_format = self.property_value('ui.date-format')
+            return ustrftime(date, date_format)
+        return u''
+
+    def format_time(self, time):
+        """return a string for a time according to instance's
+        configuration
+        """
+        if time:
+            return ustrftime(time, self.property_value('ui.time-format'))
+        return u''
+
+    def format_float(self, num):
+        """return a string for floating point number according to instance's
+        configuration
+        """
+        if num:
+            return self.property_value('ui.float-format') % num
+        return u''
+
+    def parse_datetime(self, value, etype='Datetime'):
+        """get a datetime or time from a string (according to etype)
+        Datetime formatted as Date are accepted
+        """
+        assert etype in ('Datetime', 'Date', 'Time'), etype
+        # XXX raise proper validation error
+        if etype == 'Datetime':
+            format = self.property_value('ui.datetime-format')
+            try:
+                return todatetime(strptime(value, format))
+            except ValueError:
+                pass
+        elif etype == 'Time':
+            format = self.property_value('ui.time-format')
+            try:
+                # (adim) I can't find a way to parse a Time with a custom format
+                date = strptime(value, format) # this returns a DateTime
+                return time(date.hour, date.minute, date.second)
+            except ValueError:
+                raise ValueError('can\'t parse %r (expected %s)' % (value, format))
+        try:
+            format = self.property_value('ui.date-format')
+            dt = strptime(value, format)
+            if etype == 'Datetime':
+                return todatetime(dt)
+            return todate(dt)
+        except ValueError:
+            raise ValueError('can\'t parse %r (expected %s)' % (value, format))
+
+    # abstract methods to override according to the web front-end #############
+
+    def base_url(self):
+        """return the root url of the instance"""
+        raise NotImplementedError
+
+    def decorate_rset(self, rset):
+        """add vreg/req (at least) attributes to the given result set """
+        raise NotImplementedError
+
+    def describe(self, eid):
+        """return a tuple (type, sourceuri, extid) for the entity with id <eid>"""
+        raise NotImplementedError