Edgewall Software
Modify

Opened 4 years ago

Closed 4 years ago

Last modified 4 years ago

#13244 closed defect (fixed)

Passing Jinja2 context to callable instance as first argument when the callable instance has __getattr__ method since Jinja2 2.11.0

Reported by: Jun Omae Owned by: Jun Omae
Priority: normal Milestone: 1.4.1
Component: rendering Version:
Severity: normal Keywords: jinja2
Cc: Branch:
Release Notes:
API Changes:
Internal Changes:

Skip Jinja2 context instance in Href.__call__ to fix wrong link generated from Jinja2 template since Jinja2 2.11.0.

Description (last modified by Jun Omae)

From comment:78:ticket:12130

The callable instance is Href instance.

See also

Jinja2 2.11.0

>>> import jinja2, sys
>>> jinja2.__version__
'2.11.0'
>>> from jinja2 import Template
>>> from trac.web.href import Href
>>> href = Href('/trac.cgi')
>>> Template('{{ href() }}').render(href=href)
"/trac.cgi/%3CContext%20%7B'range'%3A%20%3Cclass%20'range'%3E%2C%20'dict'%3A%20%3Cclass%20'dict'%3E%2C%20'lipsum'%3A%20%3Cfunction%20generate_lorem_ipsum%20at%200x7f0386031310%3E%2C%20'cycler'%3A%20%3Cclass%20'jinja2.utils.Cycler'%3E%2C%20'joiner'%3A%20%3Cclass%20'jinja2.utils.Joiner'%3E%2C%20'namespace'%3A%20%3Cclass%20'jinja2.utils.Namespace'%3E%2C%20'href'%3A%20%3CHref%20'/trac.cgi'%3E%7D%20of%20None%3E"
>>> class Foo(object):
...     def __getattr__(self, name):
...         sys.stderr.write('__getattr__({!r})\n'.format(name))
...         return self
...     def __call__(self, *args, **kwargs):
...         sys.stderr.write('__call__(args={!r}, kwargs={!r})\n'.format(args, kwargs))
...
>>> Template('{{ val() }}').render(val=Foo())
__getattr__('contextfunction')
__call__(args=(<Context {'range': <class 'range'>, 'dict': <class 'dict'>, 'lipsum': <function generate_lorem_ipsum at 0x7f0386031310>, 'cycler': <class 'jinja2.utils.Cycler'>, 'joiner': <class 'jinja2.utils.Joiner'>, 'namespace': <class 'jinja2.utils.Namespace'>, 'val': <__main__.Foo object at 0x7f038a15d160>} of None>,), kwargs={})
'None'

Jinja2 2.10.3

>>> import jinja2, sys
>>> jinja2.__version__
'2.10.3'
>>> from jinja2 import Template
>>> from trac.web.href import Href
>>> href = Href('/trac.cgi')
>>> Template('{{ href() }}').render(href=href)
'/trac.cgi'
>>> class Foo(object):
...     def __getattr__(self, name):
...         sys.stderr.write('__getattr__({!r})\n'.format(name))
...         return self
...     def __call__(self, *args, **kwargs):
...         sys.stderr.write('__call__(args={!r}, kwargs={!r})\n'.format(args, kwargs))
...
>>> Template('{{ val() }}').render(val=Foo())
__call__(args=(), kwargs={})
'None'

Attachments (0)

Change History (15)

comment:1 by Jun Omae, 4 years ago

Ad hoc patch:

  • trac/web/href.py

    diff --git a/trac/web/href.py b/trac/web/href.py
    index 1d2336952..170e0e3bd 100644
    a b class Href(object):  
    188188        return href
    189189
    190190    def __getattr__(self, name):
     191        if name in ('contextfunction', 'evalcontextfunction',
     192                    'environmentfunction'):
     193            raise AttributeError
    191194        if name not in self._derived:
    192195            self._derived[name] = lambda *args, **kw: self(name, *args, **kw)
    193196        return self._derived[name]

comment:2 by Jun Omae, 4 years ago

Description: modified (diff)

comment:3 by Ryan J Ollos, 4 years ago

Looks similar to Jinja2 issue #1139. Relevant change is 70ea1d3e.

Version 1, edited 4 years ago by Ryan J Ollos (previous) (next) (diff)

comment:4 by Jun Omae, 4 years ago

Proposed changes in [332bf1f51/jomae.git].

comment:5 by Ryan J Ollos, 4 years ago

Looks good. Nice solution!

comment:6 by Jun Omae, 4 years ago

Release Notes: modified (diff)
Resolution: fixed
Status: newclosed

Thanks for the review! Committed in [17238] and merged in [17239].

comment:7 by Ryan J Ollos, 4 years ago

I posted a related question in Jinja2 issue #1139.

in reply to:  7 comment:8 by Ryan J Ollos, 4 years ago

Replying to Ryan J Ollos:

I posted a related question in Jinja2 issue #1139.

They may address the issue in Jinja2 issue #1145, targeted to Jinja2 2.11.2. We can probably remove the Href attributes (contextfunction, …) if we ever drop support for Jinja < 2.11.2.

Last edited 4 years ago by Ryan J Ollos (previous) (diff)

comment:9 by Jun Omae, 4 years ago

Another work around without contextfunction attribute: we could simply ignore Jinja2 context instance because the arguments of Href.__call__() are typically instances of basestring, dict, list and tuple.

  • trac/web/href.py

    diff --git a/trac/web/href.py b/trac/web/href.py
    index 02f3cbe76..d27d2879c 100644
    a b  
    1616# Author: Jonas Borgström <jonas@edgewall.com>
    1717#         Christopher Lenz <cmlenz@gmx.de>
    1818
     19from jinja2.runtime import Context as Jinja2Context
    1920import re
    2021
    2122from trac.util.text import unicode_quote, unicode_urlencode
    class Href(object):  
    140141    '/milestone/<look,here%3E?param=%3Chere,too>'
    141142    """
    142143
    143     # Avoid passing Jinja2 context to __call__ (#13244)
    144     contextfunction = 0
    145     evalcontextfunction = 0
    146     environmentfunction = 0
    147 
    148144    def __init__(self, base, path_safe="/!~*'()", query_safe="!~*'()"):
    149145        self.base = base.rstrip('/')
    150146        self.path_safe = path_safe
    class Href(object):  
    165161            elif value is not None:
    166162                params.append((name, value))
    167163
     164        # Skip Jinja2 context (#13244)
     165        if args and isinstance(args[0], Jinja2Context):
     166            args = args[1:]
    168167        if args:
    169168            lastp = args[-1]
    170169            if isinstance(lastp, dict):
Last edited 4 years ago by Jun Omae (previous) (diff)

comment:10 by Jun Omae, 4 years ago

Owner: set to Jun Omae

comment:11 by Ryan J Ollos, 4 years ago

The comment:9 patch seems like a better solution because it doesn't prevent a path like /contextfunction.

One minor tweak is that the third-party import should be placed after the stdlib import:

import re

from jinja2.runtime import Context as Jinja2Context

from trac.util.text import unicode_quote, unicode_urlencode

comment:12 by Jun Omae, 4 years ago

Release Notes: modified (diff)

Thanks. Committed with your suggestion in [17246] and merged in [17247].

comment:13 by Ryan J Ollos, 4 years ago

I was thinking we should add a comment in the code below the Skip Jinja2 context (#13244) comment: Only needed for Jinja 2.11.0 and 2.11.1.

The workaround shouldn't be needed after 99333246.

Last edited 4 years ago by Ryan J Ollos (previous) (diff)

comment:14 by Ryan J Ollos, 4 years ago

Added additional comment in r17260, r17261.

comment:15 by Ryan J Ollos, 4 years ago

Internal Changes: modified (diff)
Release Notes: modified (diff)

Moving change notes to Internal Changes since Jinja2 2.11 compatibility is announced in #13242.

Modify Ticket

Change Properties
Set your email in Preferences
Action
as closed The owner will remain Jun Omae.
The resolution will be deleted. Next status will be 'reopened'.
to The owner will be changed from Jun Omae to the specified user.

Add Comment


E-mail address and name can be saved in the Preferences .
 
Note: See TracTickets for help on using tickets.