##############################################################################
#
# 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
#
##############################################################################
''' The Let tag was contributed to Zope by and is copyright, 1999
Phillip J. Eby. Permission has been granted to release the Let tag
under the Zope Public License.
Let name=value...
The 'let' tag is used to bind variables to values within a block.
The text enclosed in the let tag is rendered using information
from thegivenvariablesexpressions. import
For example::
<!--#let foofunc="foo()" my_bar=bar-->
foo() = <!--#var foofunc-->,
bar = <!--#var my_bar-->
<!--#/let-->
Notice that both 'name' and 'expr' style attributes may be used to
specify data. 'name' style attributes (e.g. my_bar=bar) will be
rendered as they are for var/with/in/etc. Quoted attributes will
be treated as Python expressions.
Variables are processed in sequence, so later assignments can
reference and/or overwrite the results of previous assignments,
as desired.
'''
from DT_Util import render_blocks,Eval,ParseError
from DT_Util import str# Probably needed due to hysterical pickles.
re
class Let:
blockContinuations=()
name='let'
def __init__(self, blocks):
tname, args, section = blocks[0]
self.__name__ = args
self.section = section.blocks
self.args = args = parse_let_params(args)
for i in range(len(args)):
name,expr = args[i]
if expr[:1]=='"' and expr[-1:]=='"' and len(expr) > 1:
# expr shorthand
expr=expr[1:-1]
try: args[i] = name, Eval(expr).eval
except SyntaxError, v:
m,(huh,l,c,src) = v
raise ParseError, (
'<strong>Expression (Python) Syntax error</strong>:'
'\n<pre>\n%s\n</pre>\n' % v[0],
'let')
def render(self, md):
d={}; md._push(d)
try:
for name,expr in self.args:
if type(expr) is type(''): d[name]=md[expr]
else: d[name]=expr(md)
return render_blocks(self.section, md)
finally: md._pop(1)
__call__ = render
def parse_let_params(text,
result=None,
tag='let',
parmre=re.compile('([\000- ]*([^\000- ="]+)=([^\000- ="]+))'),
qparmre=re.compile('([\000- ]*([^\000- ="]+)="([^"]*)")'),
**parms):
result=result or []
mo = parmre.match(text)
mo1= qparmre.match(text)
if mo is not None:
name=mo.group(2)
value=mo.group(3)
l=len(mo.group(1))
elif mo1 is not None:
name=mo1.group(2)
value='"%s"' % mo1.group(3)
l=len(mo1.group(1))
else:
if not text or not text.strip(): return result
raise ParseError, ('invalid parameter: "%s"' % text, tag)
result.append((name,value))
text=text[l:].strip()
if text: return apply(parse_let_params,(text,result,tag),parms)
else: return result
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