Extract definitions and descriptions for use in plugin

src/ifcblenderexport/extract.py

@@ -0,0 +1,104 @@
+import xml.sax, json, copy, pathlib
+from bs4 import BeautifulSoup
+import sys
+sys.setrecursionlimit(100)
+
+class IfcElementHandler(xml.sax.ContentHandler):
+
+    def __init__(self):
+        self.elements = {}
+        self.current_element_name = None
+        self.enums = {}
+        self.current_enum_name = None
+        self.attribute_stack = []
+
+    def startElement(self, name, attrs):
+        if name == 'xs:element'  and 'substitutionGroup' in attrs:
+            self.elements[attrs['name']] = {
+                'description': self.get_description(attrs['name']),
+                'is_abstract': True if 'abstract' in attrs else False,
+                'parent': attrs['substitutionGroup'][len('ifc:'):],
+                'attributes': []
+            }
+            self.current_element_name = attrs['name']
+        elif name == 'xs:simpleType' \
+            and 'name' in attrs \
+            and 'Enum' in attrs['name']:
+            self.current_enum_name = attrs['name']
+            self.enums[self.current_enum_name] = []
+        elif name == 'xs:enumeration' and self.current_enum_name:
+            self.enums[self.current_enum_name].append(attrs['value'].upper())
+        elif name == 'xs:attribute' \
+            and self.current_element_name \
+            and 'name' in attrs \
+            and 'type' in attrs:
+            self.elements[self.current_element_name]['attributes'].append({
+                'name': attrs['name'],
+                'type': attrs['type'].replace('ifc:', ''),
+            })
+
+    def endDocument(self):
+        elements = {}
+
+        for name, data in self.elements.items():
+            for index, attribute in enumerate(data['attributes']):
+                data['attributes'][index] = self.resolve_enums(attribute)
+
+        for name, data in self.elements.items():
+            if data['is_abstract']:
+                continue
+            if self.is_an_ifcproduct(data):
+                self.attribute_stack = []
+                self.get_parent_attributes(data)
+                elements[name] = copy.deepcopy(data)
+                elements[name]['attributes'] = copy.deepcopy(self.attribute_stack)
+
+        self.elements = elements
+
+    def get_description(self, name):
+        try:
+            filenames = pathlib.Path(
+                'io_export_ifc/schema/ifc4-add2-tc1/ifc4-add2-tc1/html/schema/').glob(
+                '**/{}.htm'.format(name.lower()))
+            for filename in filenames:
+                with open(filename, 'r') as file:
+                    soup = BeautifulSoup(file, 'html.parser')
+                    for detail in soup.find_all('details'):
+                        if detail.summary.string == 'Entity definition' \
+                            and detail.p:
+                            return str(detail.p.text.replace('\n', ' '))
+            return None
+        except:
+            return None
+            #print('Failed to get description for {}'.format(name))
+        return None
+
+    def resolve_enums(self, attribute):
+        if attribute['type'] in self.enums:
+            attribute['is_enum'] = True
+            attribute['enum_values'] = self.enums[attribute['type']]
+            return attribute
+        attribute['is_enum'] = False
+        attribute['enum_values'] = []
+        return attribute
+
+    def get_parent_attributes(self, data):
+        self.attribute_stack.extend(data['attributes'])
+        if data['parent'] != 'IfcProduct': # For now, we treat attributes above IfcProduct in a special way
+            self.get_parent_attributes(self.elements[data['parent']])
+
+    def is_an_ifcproduct(self, data):
+        if data['parent'] == 'IfcProduct':
+            return True
+        else:
+            for name, parent_data in self.elements.items():
+                if name == data['parent']:
+                    return self.is_an_ifcproduct(parent_data)
+        return False
+
+xsd_path = 'io_export_ifc/schema/IFC4.xsd'
+handler = IfcElementHandler()
+parser = xml.sax.make_parser()
+parser.setContentHandler(handler)
+parser.parse(xsd_path)
+print(json.dumps(handler.elements, indent=4))