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########################################################################
#
# File Name: Util.py
#
#
"""
Versa implementation utilities
WWW: http://4suite.org/4RDF e-mail: support@4suite.org
Copyright 2002 Fourthought Inc, USA.
See http://4suite.org/COPYRIGHT for license and copyright information
"""
from Ft.Rdf import Model
DUMMY_MODEL = Model.Model(None)
def VersaQueryGivenContext(query, context, scope=None):
from Ft.Rdf.Parsers import Versa
context.scope = scope
exp = Versa.Compile(query)
results = exp.evaluate(context)
return results
START = 1
MULTI_LINE_QUERY = 2
MULTI_LINE_VAR = 2
def ProcessQueryFile(src, inContext, logFile=None,
queryFunction=VersaQueryGivenContext, scope=None):
from Ft.Rdf.Parsers import Versa
con = inContext.clone()
var_name = ""
var_value = ""
query = ""
buffer = 0
state = START
for line in src.readlines():
if not line.strip():continue
if state == MULTI_LINE_VAR and not line[0].isspace():
result = queryFunction(var_value, con)
if logFile:
logFile.write("Assigning variable %s using: %s\n"%(var_name, var_value))
#FIXME: Support QNames
con.varBindings[(None, var_name)] = result
line = line.strip()
if line[:5] == 'QUERY':
query += line[6:]
state = MULTI_LINE_QUERY
elif line[:2] == 'NS':
name, uri = line[3:].split("=")
con.nsMapping[name] = uri
logFile.write("Adding namespace mapping: %s --> %s\n"%(name, uri))
state = START
elif line[:3] == 'VAR':
(var_name, var_value) = line[4:].split("=")
state = MULTI_LINE_VAR
elif state == MULTI_LINE_QUERY:
query += line
elif state == MULTI_LINE_VAR:
var_value += line
if logFile: logFile.write("Executing query: %s\n"%query)
result = queryFunction(query, con, scope)
return result
def ResultsToXml(result, stream, indent=u''):
# By giving a namespace, the elements are created in the null-namespace
if DataTypes.IsList(result):
stream.write(indent)
stream.write(u"<List>\n")
for r in result:
ResultsToXml(r, stream, indent+' ')
stream.write(indent)
stream.write(u"</List>\n")
elif DataTypes.IsSet(result):
stream.write(indent)
stream.write(u"<Set>\n")
for r in DataTypes.ToList(result):
ResultsToXml(r, stream, indent+u' ')
stream.write(indent)
stream.write(u"</Set>\n")
elif DataTypes.IsResource(result):
stream.write(indent)
if DUMMY_MODEL.isBnodeLabel(str(result)):
stream.write(u"<BlankNode>%s</BlankNode>\n"%unicode(result))
else:
stream.write(u"<Resource>%s</Resource>\n"%unicode(result))
elif DataTypes.IsString(result):
stream.write(indent)
stream.write(u"<String>%s</String>\n"%result)
elif DataTypes.IsNumber(result):
stream.write(indent)
stream.write(u"<Number>%s</Number>\n"%unicode(result))
elif DataTypes.IsBoolean(result):
stream.write(indent)
stream.write(u"<Boolean>%s</Boolean>\n"%unicode(result))
else:
raise Exception('Unknown Versa result type')
return
import DataTypes
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