def is_valid(self, context, obj, *args, **kwargs):
"""
Performs some basic tests against the parameters passed to it to
ensure that work should carry on afterwards.
:param context: a :class:`~django.template.Context` subclass,
or dictionary-like object which fulfils certain criteria.
Usually a :class:`~django.template.RequestContext`.
:param obj: the :class:`~django.db.models.Model`, either as a class or
an instance. Or, more specifically, anything which as a
:class:`~django.db.models.Options` object stored
under the `_meta` attribute.
:return: whether or not the context and object pair are valid.
:rtype: :data:`True` or :data:`False`
.. seealso:: :func:`~adminlinks.templatetags.utils.context_passes_test`
"""
if not hasattr(obj, '_meta'):
logger.debug('Object has no _meta attribute')
return False
if not context_passes_test(context):
logger.debug('Invalid context')
return False
return True
def get_context(self, context):
"""
Tests and updates the existing context.
:param context: a :class:`~django.template.Context` which is
checked via
:meth:`~adminlinks.templatetags.utils.context_passes_test`,
and the result **always** put into the context.
:return: the context, possibly modified with a new layer.
:rtype: :class:`~django.template.RequestContext` or other context/
dictionary-like object.
"""
result = context_passes_test(context)
context.update({'should_load_assets': result})
return context
def get_context(self, context, with_labels, admin_site):
"""
Updates the *existing* context by putting a list of applicable
modeladmins into `app_list` assuming the argument `admin_site`
resolved into an AdminSite instance.
Always returns the existing context.
"""
site = get_admin_site(admin_site)
if context_passes_test(context) and site is not None:
modeladmins = get_registered_modeladmins(context['request'], site)
context.update({
'should_display_toolbar': True,
'should_display_apps': with_labels,
'app_list': _resort_modeladmins(modeladmins),
})
return context
def get_context(self, context, *args, **kwargs):
"""
Entry point for all subsequent tags. Tests the context and bails
early if possible.
"""
who_can_see = kwargs.get('who')
if who_can_see in ('no-one', 'noone', 'none'):
logger.debug("No-one should see; didn't check context")
return {}
if (who_can_see not in ('anyone', 'all')
and not context_passes_test(context)):
logger.debug('Invalid context; button visibility was restricted')
return {}
if who_can_see == 'staff' and not context['request'].user.is_staff:
logger.debug('Valid context, but user is not marked as staff')
return {}
if (who_can_see == 'superusers'
and not context['request'].user.is_superuser):
logger.debug('Valid context, but user is not a superuser')
return {}
return self.get_link_context(context, *args, **kwargs)
