##############################################################################
#
# Copyright (c) 2001 Zope Corporation and Contributors. All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
#
##############################################################################
__doc__='''Conditional insertion
Conditional insertion is performed using 'if' and 'else'
commands.
To include text when an object is true using the EPFS
format, use::
%(if name)[
text
%(if name)]
To include text when an object is true using the HTML
format, use::
<!--#if name-->
text
<!--#/if name-->
where 'name' is the name bound to the object.
To include text when an object is false using the EPFS
format, use::
%(else name)[
text
%(else name)]
To include text when an object is false using the HTML
format, use::
<!--#else name-->
text
<!--#/else name-->
Finally to include text when an object is true and to
include different text when the object is false using the
EPFS format, use::
%(if name)[
true text
%(if name)]
%(else name)[
false text
%(else name)]
and to include text when an object is true and to
include different text when the object is false using the
HTML format, use::
<!--#if name-->
true text
<!--#else name-->
false text
<!--#/if name-->
Notes:
- if a variable is nor defined, it is considered to be false.
- A variable if only evaluated once in an 'if' tag. If the value
is used inside the tag, including in enclosed tags, the
variable is not reevaluated.
'''
__rcs_id__='$Id: DT_If.py,v 1.19 2002/08/14 22:29:52 mj Exp $'
__version__='$Revision: 1.19 $'[11:-2]
from DT_Util import ParseError,parse_params,name_param,str
class If:
blockContinuations='else','elif'
name='if'
elses=None
expr=''
def __init__(self, blocks):
tname, args, section = blocks[0]
args=parse_params(args, name='', expr='')
name,expr=name_param(args,'if',1)
self.__name__= name
if expr is None: cond=name
else: cond=expr.eval
sections=[cond, section.blocks]
if blocks[-1][0]=='else':
tname, args, section = blocks[-1]
del blocks[-1]
args=parse_params(args, name='')
if args:
ename,expr=name_param(args,'else',1)
if ename != name:
raise ParseError, ('name in else does not match if', 'in')
elses=section.blocks
else: elses=None
for tname, args, section in blocks[1:]:
if tname=='else':
raise ParseError, (
'more than one else tag for a single if tag', 'in')
args=parse_params(args, name='', expr='')
name,expr=name_param(args,'elif',1)
if expr is None: cond=name
else: cond=expr.eval
sections.append(cond)
sections.append(section.blocks)
if elses is not None: sections.append(elses)
self.simple_form=('i',)+tuple(sections)
class Unless:
name='unless'
blockContinuations=()
def __init__(self, blocks):
tname, args, section = blocks[0]
args=parse_params(args, name='', expr='')
name,expr=name_param(args,'unless',1)
if expr is None: cond=name
else: cond=expr.eval
self.simple_form=('i',cond,None,section.blocks)
class Else(Unless):
# The else tag is included for backward compatibility and is deprecated.
name='else'
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