##############################################################################
#
# Copyright (c) 2002 Zope Foundation and Contributors.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (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
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'''Inserting optional tests with 'sqlgroup'
It is sometimes useful to make inputs to an SQL statement
optinal. Doing so can be difficult, because not only must the
test be inserted conditionally, but SQL boolean operators may or
may not need to be inserted depending on whether other, possibly
optional, comparisons have been done. The 'sqlgroup' tag
automates the conditional insertion of boolean operators.
The 'sqlgroup' tag is a block tag that has no attributes. It can
have any number of 'and' and 'or' continuation tags.
Suppose we want to find all people with a given first or nick name
and optionally constrain the search by city and minimum and
maximum age. Suppose we want all inputs to be optional. We can
use DTML source like the following::
age >=
age <=
This example illustrates how groups can be nested to control
boolean evaluation order. It also illustrates that the grouping
facility can also be used with other DTML tags like 'if' tags.
The 'sqlgroup' tag checks to see if text to be inserted contains
other than whitespace characters. If it does, then it is inserted
with the appropriate boolean operator, as indicated by use of an
'and' or 'or' tag, otherwise, no text is inserted.
'''
from DocumentTemplate.DT_Util import ParseError, parse_params, name_param
from string import join, atoi, atof
from types import ListType, TupleType, StringType
class SQLTest:
name='sqltest'
optional=multiple=None
def __init__(self, args):
args = parse_params(args, name='', expr='', type=None, column=None,
multiple=1, optional=1, op=None)
name,expr = name_param(args,'sqlvar',1)
if expr is None:
expr=name
else: expr=expr.eval
self.__name__, self.expr = name, expr
self.args=args
if not args.has_key('type'):
raise ParseError, ('the type attribute is required', 'sqltest')
self.type=t=args['type']
if not valid_type(t):
raise ParseError, ('invalid type, %s' % t, 'sqltest')
if args.has_key('optional'): self.optional=args['optional']
if args.has_key('multiple'): self.multiple=args['multiple']
if args.has_key('column'):
self.column=args['column']
elif self.__name__ is None:
err = ' the column attribute is required if an expression is used'
raise ParseError, (err, 'sqltest')
else:
self.column=self.__name__
# Deal with optional operator specification
op = '=' # Default
if args.has_key('op'):
op = args['op']
# Try to get it from the chart, otherwise use the one provided
op = comparison_operators.get(op, op)
self.op = op
def render(self, md):
name=self.__name__
t=self.type
args=self.args
try:
expr=self.expr
if type(expr) is type(''):
v=md[expr]
else:
v=expr(md)
except KeyError:
if args.has_key('optional') and args['optional']:
return ''
raise ValueError, 'Missing input variable, %s' % name
if type(v) in (ListType, TupleType):
if len(v) > 1 and not self.multiple:
raise ValueError, (
'multiple values are not allowed for %s'
% name)
else: v=[v]
vs=[]
for v in v:
if not v and type(v) is StringType and t != 'string': continue
if t=='int':
try:
if type(v) is StringType:
if v[-1:]=='L':
v=v[:-1]
atoi(v)
else: v=str(int(v))
except ValueError:
raise ValueError, (
'Invalid integer value for %s' % name)
elif t=='float':
if not v and type(v) is StringType: continue
try:
if type(v) is StringType: atof(v)
else: v=str(float(v))
except ValueError:
raise ValueError, (
'Invalid floating-point value for %s' % name)
else:
if not isinstance(v, (str, unicode)):
v = str(v)
v=md.getitem('sql_quote__',0)(v)
#if find(v,"\'") >= 0: v=join(split(v,"\'"),"''")
#v="'%s'" % v
vs.append(v)
if not vs and t=='nb':
if args.has_key('optional') and args['optional']:
return ''
else:
err = 'Invalid empty string value for %s' % name
raise ValueError, err
if not vs:
if self.optional: return ''
raise ValueError, (
'No input was provided for %s' % name)
if len(vs) > 1:
vs=join(map(str,vs),', ')
if self.op == '<>':
## Do the equivalent of 'not-equal' for a list,
## "a not in (b,c)"
return "%s not in (%s)" % (self.column, vs)
else:
## "a in (b,c)"
return "%s in (%s)" % (self.column, vs)
return "%s %s %s" % (self.column, self.op, vs[0])
__call__=render
valid_type={'int':1, 'float':1, 'string':1, 'nb': 1}.has_key
comparison_operators = { 'eq': '=', 'ne': '<>',
'lt': '<', 'le': '<=', 'lte': '<=',
'gt': '>', 'ge': '>=', 'gte': '>=' }