week06

env/lib/python3.12/site-packages/lxml/schematron.pxi

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+# support for Schematron validation
+from lxml.includes cimport schematron
+
+
+cdef class SchematronError(LxmlError):
+    """Base class of all Schematron errors.
+    """
+
+cdef class SchematronParseError(SchematronError):
+    """Error while parsing an XML document as Schematron schema.
+    """
+
+cdef class SchematronValidateError(SchematronError):
+    """Error while validating an XML document with a Schematron schema.
+    """
+
+
+################################################################################
+# Schematron
+
+cdef class Schematron(_Validator):
+    """Schematron(self, etree=None, file=None)
+    A Schematron validator.
+
+    Pass a root Element or an ElementTree to turn it into a validator.
+    Alternatively, pass a filename as keyword argument 'file' to parse from
+    the file system.
+
+    Schematron is a less well known, but very powerful schema language.  The main
+    idea is to use the capabilities of XPath to put restrictions on the structure
+    and the content of XML documents.  Here is a simple example::
+
+      >>> schematron = Schematron(XML('''
+      ... <schema xmlns="http://www.ascc.net/xml/schematron" >
+      ...   <pattern name="id is the only permitted attribute name">
+      ...     <rule context="*">
+      ...       <report test="@*[not(name()='id')]">Attribute
+      ...         <name path="@*[not(name()='id')]"/> is forbidden<name/>
+      ...       </report>
+      ...     </rule>
+      ...   </pattern>
+      ... </schema>
+      ... '''))
+
+      >>> xml = XML('''
+      ... <AAA name="aaa">
+      ...   <BBB id="bbb"/>
+      ...   <CCC color="ccc"/>
+      ... </AAA>
+      ... ''')
+
+      >>> schematron.validate(xml)
+      0
+
+      >>> xml = XML('''
+      ... <AAA id="aaa">
+      ...   <BBB id="bbb"/>
+      ...   <CCC/>
+      ... </AAA>
+      ... ''')
+
+      >>> schematron.validate(xml)
+      1
+
+    Schematron was added to libxml2 in version 2.6.21.  Before version 2.6.32,
+    however, Schematron lacked support for error reporting other than to stderr.
+    This version is therefore required to retrieve validation warnings and
+    errors in lxml.
+    """
+    cdef schematron.xmlSchematron* _c_schema
+    cdef xmlDoc* _c_schema_doc
+    def __cinit__(self):
+        self._c_schema = NULL
+        self._c_schema_doc = NULL
+
+    def __init__(self, etree=None, *, file=None):
+        cdef _Document doc
+        cdef _Element root_node
+        cdef xmlNode* c_node
+        cdef char* c_href
+        cdef schematron.xmlSchematronParserCtxt* parser_ctxt = NULL
+        _Validator.__init__(self)
+        if not config.ENABLE_SCHEMATRON:
+            raise SchematronError, \
+                "lxml.etree was compiled without Schematron support."
+        if etree is not None:
+            doc = _documentOrRaise(etree)
+            root_node = _rootNodeOrRaise(etree)
+            self._c_schema_doc = _copyDocRoot(doc._c_doc, root_node._c_node)
+            parser_ctxt = schematron.xmlSchematronNewDocParserCtxt(self._c_schema_doc)
+        elif file is not None:
+            filename = _getFilenameForFile(file)
+            if filename is None:
+                # XXX assume a string object
+                filename = file
+            filename = _encodeFilename(filename)
+            with self._error_log:
+                orig_loader = _register_document_loader()
+                parser_ctxt = schematron.xmlSchematronNewParserCtxt(_cstr(filename))
+                _reset_document_loader(orig_loader)
+        else:
+            raise SchematronParseError, "No tree or file given"
+
+        if parser_ctxt is NULL:
+            if self._c_schema_doc is not NULL:
+                tree.xmlFreeDoc(self._c_schema_doc)
+                self._c_schema_doc = NULL
+            raise MemoryError()
+
+        try:
+            with self._error_log:
+                orig_loader = _register_document_loader()
+                self._c_schema = schematron.xmlSchematronParse(parser_ctxt)
+                _reset_document_loader(orig_loader)
+        finally:
+            schematron.xmlSchematronFreeParserCtxt(parser_ctxt)
+
+        if self._c_schema is NULL:
+            raise SchematronParseError(
+                "Document is not a valid Schematron schema",
+                self._error_log)
+
+    def __dealloc__(self):
+        schematron.xmlSchematronFree(self._c_schema)
+        if self._c_schema_doc is not NULL:
+            tree.xmlFreeDoc(self._c_schema_doc)
+
+    def __call__(self, etree):
+        """__call__(self, etree)
+
+        Validate doc using Schematron.
+
+        Returns true if document is valid, false if not."""
+        cdef _Document doc
+        cdef _Element root_node
+        cdef xmlDoc* c_doc
+        cdef schematron.xmlSchematronValidCtxt* valid_ctxt
+        cdef int ret
+
+        assert self._c_schema is not NULL, "Schematron instance not initialised"
+        doc = _documentOrRaise(etree)
+        root_node = _rootNodeOrRaise(etree)
+
+        valid_ctxt = schematron.xmlSchematronNewValidCtxt(
+            self._c_schema, schematron.XML_SCHEMATRON_OUT_ERROR)
+        if valid_ctxt is NULL:
+            raise MemoryError()
+
+        try:
+            self._error_log.clear()
+            # Need a cast here because older libxml2 releases do not use 'const' in the functype.
+            schematron.xmlSchematronSetValidStructuredErrors(
+                valid_ctxt, <xmlerror.xmlStructuredErrorFunc> _receiveError, <void*>self._error_log)
+            c_doc = _fakeRootDoc(doc._c_doc, root_node._c_node)
+            with nogil:
+                ret = schematron.xmlSchematronValidateDoc(valid_ctxt, c_doc)
+            _destroyFakeDoc(doc._c_doc, c_doc)
+        finally:
+            schematron.xmlSchematronFreeValidCtxt(valid_ctxt)
+
+        if ret == -1:
+            raise SchematronValidateError(
+                "Internal error in Schematron validation",
+                self._error_log)
+        if ret == 0:
+            return True
+        else:
+            return False