Source Code for Module xmlschema_acue.validators.assertions

 1  # -*- coding: utf-8 -*- 
 2  # 
 3  # Copyright (c), 2016-2019, SISSA (International School for Advanced Studies). 
 4  # All rights reserved. 
 5  # This file is distributed under the terms of the MIT License. 
 6  # See the file 'LICENSE' in the root directory of the present 
 7  # distribution, or http://opensource.org/licenses/MIT. 
 8  # 
 9  # @author Davide Brunato <brunato@sissa.it> 
10  # 
11  from __future__ import unicode_literals 
12  from elementpath import XPath2Parser, XPathContext, XMLSchemaProxy, ElementPathSyntaxError 
13   
14  from xmlschema_acue.qnames import XSD_ASSERT 
15  from xmlschema_acue.xpath import ElementPathMixin 
16   
17  from xmlschema_acue.validators.exceptions import XMLSchemaValidationError 
18  from xmlschema_acue.validators.xsdbase import XsdComponent 
19   
20   
21 -class XsdAssert(XsdComponent, ElementPathMixin): 
22      """ 
23      Class for XSD 'assert' constraint declaration. 
24   
25      <assert 
26        id = ID 
27        test = an XPath expression 
28        xpathDefaultNamespace = (anyURI | (##defaultNamespace | ##targetNamespace | ##local)) 
29        {any attributes with non-schema namespace . . .}> 
30        Content: (annotation?) 
31      </assert> 
32      """ 
33      _admitted_tags = {XSD_ASSERT} 
34      token = None 
35   
36 -    def __init__(self, elem, schema, parent, base_type): 
37          self.base_type = base_type 
38          super(XsdAssert, self).__init__(elem, schema, parent) 
39          if not self.base_type.is_complex(): 
40              self.parse_error("base_type={!r} is not a complexType definition", elem=self.elem) 
41              self.path = 'true()' 
42   
43 -    def _parse(self): 
44          super(XsdAssert, self)._parse() 
45          try: 
46              self.path = self.elem.attrib['test'] 
47          except KeyError as err: 
48              self.parse_error(str(err), elem=self.elem) 
49              self.path = 'true()' 
50   
51          if 'xpathDefaultNamespace' in self.elem.attrib: 
52              self.xpath_default_namespace = self._parse_xpath_default_namespace(self.elem) 
53          else: 
54              self.xpath_default_namespace = self.schema.xpath_default_namespace 
55          self.parser = XPath2Parser(self.namespaces, strict=False, default_namespace=self.xpath_default_namespace) 
56   
57      @property 
58 -    def built(self): 
59          return self.token is not None and (self.base_type.is_global or self.base_type.built) 
60   
61 -    def parse(self): 
62          self.parser.schema = XMLSchemaProxy(self.schema, self) 
63          try: 
64              self.token = self.parser.parse(self.path) 
65          except ElementPathSyntaxError as err: 
66              self.parse_error(err, elem=self.elem) 
67              self.token = self.parser.parse('true()') 
68   
69 -    def __call__(self, elem): 
70          if not self.token.evaluate(XPathContext(root=elem)): 
71              msg = "expression is not true with test path %r." 
72              yield XMLSchemaValidationError(self, obj=elem, reason=msg % self.path) 
73   
74      # For implementing ElementPathMixin 
75 -    def __iter__(self): 
76          if not self.parent.has_simple_content(): 
77              for e in self.parent.content_type.iter_subelements(): 
78                  yield e 
79   
80      @property 
81 -    def attrib(self): 
82          return self.parent.attributes 
83