Source Code for Module qm.external.DocumentTemplate.DT_If

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  3  # Copyright (c) 2002 Zope Corporation and Contributors. All Rights Reserved. 
  4  # 
  5  # This software is subject to the provisions of the Zope Public License, 
  6  # Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution. 
  7  # THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED 
  8  # WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
  9  # WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS 
 10  # FOR A PARTICULAR PURPOSE 
 11  # 
 12  ############################################################################## 
 13  __doc__='''Conditional insertion 
 14   
 15         Conditional insertion is performed using 'if' and 'else' 
 16         commands. 
 17   
 18         To include text when an object is true using the EPFS 
 19         format, use:: 
 20   
 21            %(if name)[ 
 22                 text 
 23            %(if name)] 
 24   
 25         To include text when an object is true using the HTML 
 26         format, use:: 
 27   
 28            <!--#if name--> 
 29                 text 
 30            <!--#/if name--> 
 31   
 32         where 'name' is the name bound to the object. 
 33   
 34         To include text when an object is false using the EPFS 
 35         format, use:: 
 36   
 37            %(else name)[ 
 38                 text 
 39            %(else name)] 
 40   
 41         To include text when an object is false using the HTML 
 42         format, use:: 
 43   
 44            <!--#else name--> 
 45                 text 
 46            <!--#/else name--> 
 47   
 48         Finally to include text when an object is true and to 
 49         include different text when the object is false using the 
 50         EPFS format, use:: 
 51   
 52            %(if name)[ 
 53                 true text 
 54            %(if name)] 
 55            %(else name)[ 
 56                 false text 
 57            %(else name)] 
 58   
 59         and to include text when an object is true and to 
 60         include different text when the object is false using the 
 61         HTML format, use:: 
 62   
 63            <!--#if name--> 
 64                 true text 
 65            <!--#else name--> 
 66                 false text 
 67            <!--#/if name--> 
 68   
 69         Notes: 
 70   
 71         - if a variable is nor defined, it is considered to be false. 
 72   
 73         - A variable if only evaluated once in an 'if' tag.  If the value 
 74           is used inside the tag, including in enclosed tags, the 
 75           variable is not reevaluated. 
 76   
 77  ''' 
 78  __rcs_id__='$Id: DT_If.py 1069 2008-11-13 21:55:43Z stefan $' 
 79  __version__='$Revision: 1069 $'[11:-2] 
 80   
 81  from DT_Util import ParseError, parse_params, name_param, str 
 82   
 83 -class If: 
 84      blockContinuations='else','elif' 
 85      name='if' 
 86      elses=None 
 87      expr='' 
 88   
 89 -    def __init__(self, blocks): 
 90   
 91          tname, args, section = blocks[0] 
 92          args=parse_params(args, name='', expr='') 
 93          name,expr=name_param(args,'if',1) 
 94          self.__name__= name 
 95          if expr is None: cond=name 
 96          else: cond=expr.eval 
 97          sections=[cond, section.blocks] 
 98   
 99          if blocks[-1][0]=='else': 
100              tname, args, section = blocks[-1] 
101              del blocks[-1] 
102              args=parse_params(args, name='') 
103              if args: 
104                  ename,expr=name_param(args,'else',1) 
105                  if ename != name: 
106                      raise ParseError, ('name in else does not match if', 'in') 
107              elses=section.blocks 
108          else: elses=None 
109   
110          for tname, args, section in blocks[1:]: 
111              if tname=='else': 
112                  raise ParseError, ( 
113                      'more than one else tag for a single if tag', 'in') 
114              args=parse_params(args, name='', expr='') 
115              name,expr=name_param(args,'elif',1) 
116              if expr is None: cond=name 
117              else: cond=expr.eval 
118              sections.append(cond) 
119              sections.append(section.blocks) 
120   
121          if elses is not None: sections.append(elses) 
122   
123          self.simple_form=tuple(sections) 
124   
125 -class Unless: 
126      name='unless' 
127      blockContinuations=() 
128   
129 -    def __init__(self, blocks): 
130          tname, args, section = blocks[0] 
131          args=parse_params(args, name='', expr='') 
132          name,expr=name_param(args,'unless',1) 
133          if expr is None: cond=name 
134          else: cond=expr.eval 
135          self.simple_form=(cond,None,section.blocks) 
136   
137 -class Else(Unless): 
138      # The else tag is included for backward compatibility and is deprecated. 
139      name='else' 
140