##############################################################################
#
# Copyright (c) 2002 Zope Corporation and Contributors.
# All Rights Reserved.
#
# 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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##############################################################################
"""Sequence insertion
A sequence may be inserted using an 'in' command. The 'in'
command specifies the name of a sequence object and text to
be inserted for each element in the sequence.
The EPFS syntax for the in command is::
%(in name)[
text
%(in name)]
The HTML syntax for the in command is::
text
See the example below that shows how 'if', 'else', and 'in' commands
may be combined to display a possibly empty list of objects.
The text included within an 'in' command will be refered to
as an 'in' block.
Synopsis
If the variable 'sequence' exists as a sequence, a simple case
of the 'in' tag is used as follows::
some markup
A more complete case is used as follows::
)
Attributes
sort -- Define the sort order for sequence items. If an item in
the sequence does not define
sort_expr -- This allows an expression to control sort order.
reverse -- Reverse the sequence (may be combined with sort). Note
that this can cause a huge memory use in lazy activation instances.
reverse_expr -- This allows reversing to be controlled by an expression.
Within an 'in' block, variables are substituted from the
elements of the iteration. The elements may be either
instance or mapping objects. In addition, the variables:
'sequence-item' -- The element.
'sequence-var-nnn' -- The value of a specific named attribute
of the item, where 'nnn' is the name. For example, to get
an items 'title' attribute, use 'sequence-var-title'. This
construct is most useful in an 'if' tag to test whether an
attribute is present, because the attribute lookup will be
extended to the full document template namespace.
'sequence-key' -- The key associated with the element in an
items list. See below.
'sequence-index' -- The index, starting from 0, of the
element within the sequence.
'sequence-number' -- The index, starting from 1, of the
element within the sequence.
'sequence-letter' -- The index, starting from 'a', of the
element within the sequence.
'sequence-Letter' -- The index, starting from 'A', of the
element within the sequence.
'sequence-roman' -- The index, starting from 'i', of the
element within the sequence.
'sequence-Roman' -- The index, starting from 'I', of the
element within the sequence.
'sequence-start' -- A variable that is true if the element
being displayed is the first of the displayed elements,
and false otherwise.
'sequence-end' -- A variable that is true if the element
being displayed is the last of the displayed elements,
and false otherwise.
are defined for each element.
Normally, 'in' blocks are used to iterate over sequences of
instances. If the optional parameter 'mapping' is specified
after the sequence name, then the elements of the sequence
will be treated as mapping objects.
An 'in' command may be used to iterate over a sequence of
dictionary items. If the elements of the iteration are
two-element tuples, then then the template code given in the
'in' block will be applied to the second element of each
tuple and may use a variable, 'sequence-key' to access the
first element in each tuple.
Batch sequence insertion
When displaying a large number of objects, it is sometimes
desirable to display just a sub-sequence of the data.
An 'in' command may have optional parameters,
as in::
The parameter values may be either integer literals or
variable names.
Up to five parameters may be set:
'start' -- The number of the first element to be shown,
where elements are numbered from 1.
'end' -- The number of the last element to be shown,
where elements are numbered from 1.
'size' -- The desired number of elements to be shown at
once.
'orphan' -- The desired minimum number of objects to be
displayed. The default value for this
parameter is 3.
'overlap' -- The desired overlap between batches. The
default is no overlap.
Typically, only 'start' and 'size' will be specified.
When batch insertion is used, several additional variables are
defined for use within the sequence insertion text:
'sequence-query' -- The original query string given in a get
request with the form variable named in the 'start'
attribute removed. This is extremely useful when
building URLs to fetch another batch.
To see how this is used, consider the following example::
... display rows
(Next results)
If the original URL is: 'foo/bar?x=1&y=2', then the
rendered text (after row data are displayed) will be::
(Next 20 results)
If the original URL is: 'foo/bar?batch_start=10&x=1&y=2',
then the rendered text (after row data are displayed)
will be::
(Next 20 results)
'sequence-step-start-index' -- The index, starting from 0,
of the start of the current batch.
'sequence-step-end-index' -- The index, starting from 0, of
the end of the current batch.
'sequence-step-size' -- The batch size used.
'previous-sequence' -- This variable will be true when the
first element is displayed and when the first element
displayed is not the first element in the sequence.
'previous-sequence-start-index' -- The index, starting from
0, of the start of the batch previous to the current
batch.
'previous-sequence-end-index' -- The index, starting from
0, of the end of the batch previous to the current
batch.
'previous-sequence-size' -- The size of the batch previous to
the current batch.
'previous-batches' -- A sequence of mapping objects
containing information about all of the batches prior
to the batch being displayed.
Each of these mapping objects include the following
variables:
batch-start-index -- The index, starting from
0, of the beginning of the batch.
batch-end-index -- The index, starting from
0, of the end of the batch.
batch-size -- The size of the batch.
'next-sequence' -- This variable will be true when the last
element is displayed and when the last element
displayed is not the last element in the sequence.
'next-sequence-start-index' -- The index, starting from
0, of the start of the batch after the current
batch.
'next-sequence-end-index' -- The index, starting from
0, of the end of the batch after the current
batch.
'next-sequence-size' -- The size of the batch after
the current batch.
'next-batches' -- A sequence of mapping objects
containing information about all of the batches after
the batch being displayed.
Each of these mapping objects include the following
variables:
batch-start-index -- The index, starting from
0, of the beginning of the batch.
batch-end-index -- The index, starting from
0, of the end of the batch.
batch-size -- The size of the batch.
For each of the variables listed above with names ending in
"-index", there are variables with names ending in "-number",
"-roman", "-Roman", "-letter", and "-Letter" that are indexed
from 1, "i", "I", "a", and "A", respectively. In addition,
for every one of these variables there are variables with
names ending in "-var-xxx", where "xxx" is an element
attribute name or key.
Summary statistics
When performing sequence insertion, special variables may be
used to obtain summary statistics. To obtain a summary
statistic for a variable, use the variable name:
'statistic-name', where 'statistic' is a statistic name and
'name' is the name of a data variable.
Currently supported statistic names are:
total -- The total of numeric values.
count -- The total number of non-missing values.
min -- The minimum of non-missing values.
max -- The maximum of non-missing values.
median -- The median of non-missing values.
mean -- The mean of numeric values values.
variance -- The variance of numeric values computed with a
degrees of freedom equal to the count - 1.
variance-n -- The variance of numeric values computed with a
degrees of freedom equal to the count.
standard-deviation -- The standard deviation of numeric values
computed with a degrees of freedom equal to the count - 1.
standard-deviation-n -- The standard deviation of numeric
values computed with a degrees of freedom equal to the count.
Missing values are 'None'.
'else' continuation tag within in
An 'else' tag may be used as a continuation tag in the 'in' tag.
The source after the 'else' tag is inserted if:
- The sequence given to the 'in' tag is of zero length, or
- The 'previous' attribute was used and their are no
previous batches, or
- The 'next' attribute was used and their are no
next batches, or
$Id: dt_in.py 38178 2005-08-30 21:50:19Z mj $
"""
from zope.documenttemplate.dt_util import ParseError, parse_params, name_param
from zope.documenttemplate.dt_util import render_blocks, ValidationError, Eval
import re
from zope.documenttemplate.dt_insv import sequence_variables, opt
from types import StringType, ListType, TupleType, IntType, FloatType, NoneType
class InFactory:
blockContinuations = ('else',)
name = 'in'
def __call__(self, context, blocks):
i = InClass(context, blocks)
if i.batch:
return i.renderwb
else:
return i.renderwob
In = InFactory()
class InError(Exception):
"""Strings are not allowed as input to the in tag"""
class InClass:
elses = None
expr = sort = batch = mapping = None
start_name_re = None
reverse = None
sort_expr = reverse_expr = None
def __init__(self, context, blocks):
tname, args, section = blocks[0]
args=parse_params(args, name='', start='1',end='-1',size='10',
orphan='3',overlap='1',mapping=1,
skip_unauthorized=1,
previous=1, next=1, expr='', sort='',
reverse=1, sort_expr='', reverse_expr='')
self.args=args
has_key=args.has_key
if has_key('sort'):
self.sort=sort=args['sort']
if sort=='sequence-item': self.sort=''
if has_key('sort_expr'):
self.sort_expr = Eval(context, args['sort_expr'])
if has_key('reverse_expr'):
self.reverse_expr = Eval(context, args['reverse_expr'])
if has_key('reverse'):
self.reverse = args['reverse']
if has_key('mapping'):
self.mapping = args['mapping']
for n in 'start', 'size', 'end':
if has_key(n):
self.batch=1
for n in 'orphan','overlap','previous','next':
if has_key(n) and not self.batch:
raise ParseError(
"""
The %s attribute was used but neither of the
start, end, or size
attributes were used.
""" % n, 'in')
if has_key('start'):
v = args['start']
if isinstance(v, StringType):
try: v.atoi()
except:
self.start_name_re = re.compile(
'&+'+
''.join(map(lambda c: "[%s]" % c, v))+
'=[0-9]+&+')
name, expr = name_param(context, args, 'in', 1)
if expr is not None:
expr = expr.eval
self.__name__, self.expr = name, expr
self.section = section.blocks
if len(blocks) > 1:
if len(blocks) != 2: raise ParseError(
'too many else blocks', 'in')
tname, args, section = blocks[1]
args=parse_params(args, name='')
if args:
ename = name_param(context, args)
if ename != name:
raise ParseError(
'name in else does not match in', 'in')
self.elses = section.blocks
def renderwb(self, md):
expr = self.expr
name = self.__name__
if expr is None:
sequence = md[name]
cache = {name: sequence }
else:
sequence = expr(md)
cache = None
if not sequence:
if self.elses:
return render_blocks(self.elses, md)
return ''
if isinstance(sequence, StringType):
raise InError('Strings are not allowed as input to the in tag.')
section = self.section
params = self.args
mapping = self.mapping
if self.sort_expr is not None:
self.sort = self.sort_expr.eval(md)
sequence = self.sort_sequence(sequence)
elif self.sort is not None:
sequence = self.sort_sequence(sequence)
if self.reverse_expr is not None and self.reverse_expr.eval(md):
sequence = self.reverse_sequence(sequence)
elif self.reverse is not None:
sequence = self.reverse_sequence(sequence)
next = previous = 0
try:
start = int_param(params, md, 'start', 0)
except:
start=1
end = int_param(params, md, 'end', 0)
size = int_param(params, md, 'size', 0)
overlap = int_param(params, md, 'overlap', 0)
orphan = int_param(params, md, 'orphan', '3')
start, end, sz = opt(start, end, size, orphan, sequence)
if params.has_key('next'):
next = 1
if params.has_key('previous'):
previous = 1
last = end - 1
first = start - 1
try:
query_string = md['QUERY_STRING']
except:
query_string = ''
vars = sequence_variables(sequence,'?' + query_string,
self.start_name_re)
kw = vars.data
kw['mapping'] = mapping
kw['sequence-step-size'] = sz
kw['sequence-step-overlap'] = overlap
kw['sequence-step-start'] = start
kw['sequence-step-end'] = end
kw['sequence-step-start-index'] = start - 1
kw['sequence-step-end-index'] = end - 1
kw['sequence-step-orphan'] = orphan
push = md._push
pop = md._pop
render = render_blocks
if cache:
push(cache)
push(vars)
try:
if previous:
if first > 0:
pstart, pend, psize = opt(0, first+overlap,
sz, orphan, sequence)
kw['previous-sequence'] = 1
kw['previous-sequence-start-index'] = pstart - 1
kw['previous-sequence-end-index'] = pend - 1
kw['previous-sequence-size'] = pend + 1 - pstart
result=render(section,md)
elif self.elses:
result = render(self.elses, md)
else:
result = ''
elif next:
try:
# The following line is a sneaky way to test whether
# there are more items, without actually
# computing a length:
sequence[end]
except IndexError:
if self.elses:
result = render(self.elses, md)
else:
result = ''
else:
pstart, pend, psize = opt(end+1-overlap, 0,
sz, orphan, sequence)
kw['next-sequence'] = 1
kw['next-sequence-start-index'] = pstart - 1
kw['next-sequence-end-index'] = pend - 1
kw['next-sequence-size'] = pend + 1 - pstart
result = render(section, md)
else:
result = []
append = result.append
validate = md.validate
for index in range(first,end):
# preset
kw['previous-sequence'] = 0
# now more often defined then previously
kw['next-sequence'] = 0
if index==first or index==last:
# provide batching information
if first > 0:
pstart, pend, psize = opt(0, first + overlap,
sz, orphan, sequence)
if index == first:
kw['previous-sequence'] = 1
kw['previous-sequence-start-index'] = pstart - 1
kw['previous-sequence-end-index'] = pend - 1
kw['previous-sequence-size'] = pend + 1 - pstart
try:
# The following line is a sneaky way to
# test whether there are more items,
# without actually computing a length:
sequence[end]
pstart, pend, psize = opt(end + 1 - overlap, 0,
sz, orphan, sequence)
if index == last:
kw['next-sequence'] = 1
kw['next-sequence-start-index'] = pstart - 1
kw['next-sequence-end-index'] = pend - 1
kw['next-sequence-size'] = pend + 1 - pstart
except:
pass
if index == last:
kw['sequence-end'] = 1
client = sequence[index]
if validate is not None:
try:
vv = validate(sequence, sequence, None, client,md)
except:
vv = 0
if not vv:
if (params.has_key('skip_unauthorized') and
params['skip_unauthorized']):
if index == first:
kw['sequence-start'] = 0
continue
raise ValidationError(index)
kw['sequence-index'] = index
if isinstance(client, TupleType) and len(client) == 2:
client = client[1]
if mapping:
push(client)
else:
md._push_instance(client)
try:
append(render(section, md))
finally:
pop(1)
if index == first:
kw['sequence-start'] = 0
result = ''.join(result)
finally:
if cache:
pop()
pop()
return result
def renderwob(self, md):
"""RENDER WithOutBatch"""
expr = self.expr
name = self.__name__
if expr is None:
sequence = md[name]
cache = {name: sequence }
else:
sequence = expr(md)
cache = None
if not sequence:
if self.elses:
return render_blocks(self.elses, md)
return ''
if isinstance(sequence, StringType):
raise InError('Strings are not allowed as input to the in tag.')
section = self.section
mapping = self.mapping
if self.sort_expr is not None:
self.sort = self.sort_expr.eval(md)
sequence = self.sort_sequence(sequence)
elif self.sort is not None:
sequence = self.sort_sequence(sequence)
if self.reverse_expr is not None and self.reverse_expr.eval(md):
sequence = self.reverse_sequence(sequence)
elif self.reverse is not None:
sequence = self.reverse_sequence(sequence)
vars = sequence_variables(sequence)
kw = vars.data
kw['mapping'] = mapping
l = len(sequence)
last = l - 1
push = md._push
pop = md._pop
render = render_blocks
get = self.args.get
if cache:
push(cache)
push(vars)
try:
result = []
append = result.append
validate = md.validate
for index in range(l):
if index == last:
kw['sequence-end'] = 1
client = sequence[index]
if validate is not None:
try:
vv = validate(sequence, sequence, None, client, md)
except:
vv = 0
if not vv:
if get('skip_unauthorized'):
if index == 1:
kw['sequence-start'] = 0
continue
raise ValidationError(index)
kw['sequence-index'] = index
if isinstance(client, TupleType) and len(client) == 2:
client = client[1]
if mapping:
push(client)
else:
md._push_instance(client)
try:
append(render(section, md))
finally:
pop()
if index == 0:
kw['sequence-start'] = 0
result = ''.join(result)
finally:
if cache:
pop()
pop()
return result
def sort_sequence(self, sequence):
# Modified with multiple sort fields by Ross Lazarus
# April 7 2000 rossl@med.usyd.edu.au
# eg
sort = self.sort
sortfields = sort.split(',') # multi sort = key1,key2
multsort = len(sortfields) > 1 # flag: is multiple sort
mapping = self.mapping
isort = not sort
s = []
for client in sequence:
k = None
if isinstance(client, TupleType) and len(client)==2:
if isort:
k = client[0]
v = client[1]
else:
if isort:
k = client
v = client
if sort:
if multsort: # More than one sort key.
k = []
for sk in sortfields:
try:
if mapping:
akey = v[sk]
else:
akey = getattr(v, sk)
except AttributeError, KeyError:
akey = None
if not basic_type(akey):
try:
akey = akey()
except:
pass
k.append(akey)
else: # One sort key.
try:
if mapping:
k = v[sort]
else:
k = getattr(v, sort)
except AttributeError, KeyError:
k = None
if not basic_type(type(k)):
try:
k = k()
except:
pass
s.append((k,client))
s.sort()
sequence = []
for k, client in s:
sequence.append(client)
return sequence
def reverse_sequence(self, sequence):
s = list(sequence)
s.reverse()
return s
basic_type = {StringType: 1, IntType: 1, FloatType: 1, TupleType: 1,
ListType: 1, NoneType: 1}.has_key
def int_param(params, md, name, default=0, st=StringType):
try:
v = params[name]
except:
v = default
if v:
try:
v = v.atoi()
except:
v = md[v]
if isinstance(v, st):
v = v.atoi()
return v