+++ /dev/null
-# Source: http://djangosnippets.org/snippets/967/
-# Author: adurdin
-# Posted: August 13, 2008
-#
-#
-# We can use it based on djangosnippets Terms of Service:
-# (http://djangosnippets.org/about/tos/)
-#
-# 2. That you grant any third party who sees the code you post
-# a royalty-free, non-exclusive license to copy and distribute that code
-# and to make and distribute derivative works based on that code. You may
-# include license terms in snippets you post, if you wish to use
-# a particular license (such as the BSD license or GNU GPL), but that
-# license must permit royalty-free copying, distribution and modification
-# of the code to which it is applied.
-
-from django import template
-from django.template import Library, Node, VariableDoesNotExist
-
-register = Library()
-
-
-@register.tag(name="switch")
-def do_switch(parser, token):
- """
- The ``{% switch %}`` tag compares a variable against one or more values in
- ``{% case %}`` tags, and outputs the contents of the matching block. An
- optional ``{% else %}`` tag sets off the default output if no matches
- could be found::
-
- {% switch result_count %}
- {% case 0 %}
- There are no search results.
- {% case 1 %}
- There is one search result.
- {% else %}
- Jackpot! Your search found {{ result_count }} results.
- {% endswitch %}
-
- Each ``{% case %}`` tag can take multiple values to compare the variable
- against::
-
- {% switch username %}
- {% case "Jim" "Bob" "Joe" %}
- Me old mate {{ username }}! How ya doin?
- {% else %}
- Hello {{ username }}
- {% endswitch %}
- """
- bits = token.contents.split()
- tag_name = bits[0]
- if len(bits) != 2:
- raise template.TemplateSyntaxError("'%s' tag requires one argument" % tag_name)
- variable = parser.compile_filter(bits[1])
-
- class BlockTagList(object):
- # This is a bit of a hack, as it embeds knowledge of the behaviour
- # of Parser.parse() relating to the "parse_until" argument.
- def __init__(self, *names):
- self.names = set(names)
-
- def __contains__(self, token_contents):
- name = token_contents.split()[0]
- return name in self.names
-
- # Skip over everything before the first {% case %} tag
- parser.parse(BlockTagList('case', 'endswitch'))
-
- cases = []
- token = parser.next_token()
- got_case = False
- got_else = False
- while token.contents != 'endswitch':
- nodelist = parser.parse(BlockTagList('case', 'else', 'endswitch'))
-
- if got_else:
- raise template.TemplateSyntaxError("'else' must be last tag in '%s'." % tag_name)
-
- contents = token.contents.split()
- token_name, token_args = contents[0], contents[1:]
-
- if token_name == 'case':
- tests = map(parser.compile_filter, token_args)
- case = (tests, nodelist)
- got_case = True
- else:
- # The {% else %} tag
- case = (None, nodelist)
- got_else = True
- cases.append(case)
- token = parser.next_token()
-
- if not got_case:
- raise template.TemplateSyntaxError("'%s' must have at least one 'case'." % tag_name)
-
- return SwitchNode(variable, cases)
-
-
-class SwitchNode(Node):
- def __init__(self, variable, cases):
- self.variable = variable
- self.cases = cases
-
- def __repr__(self):
- return "<Switch node>"
-
- def __iter__(self):
- for tests, nodelist in self.cases:
- for node in nodelist:
- yield node
-
- def get_nodes_by_type(self, nodetype):
- nodes = []
- if isinstance(self, nodetype):
- nodes.append(self)
- for tests, nodelist in self.cases:
- nodes.extend(nodelist.get_nodes_by_type(nodetype))
- return nodes
-
- def render(self, context):
- try:
- value_missing = False
- value = self.variable.resolve(context, True)
- except VariableDoesNotExist:
- no_value = True
- value_missing = None
- value = None
-
- for tests, nodelist in self.cases:
- if tests is None:
- return nodelist.render(context)
- elif not value_missing:
- for test in tests:
- test_value = test.resolve(context, True)
- if value == test_value:
- return nodelist.render(context)
- else:
- return ""
fnp / wolnelektury.git / blobdiff