mvd info to module, add testing, setattr & getattr

src/ifcopenshell-python/ifcopenshell/file.py

@@ -37,9 +37,7 @@ from typing import Any
 from . import ifcopenshell_wrapper
 from .entity_instance import entity_instance
 
-from lark import Lark, Transformer
+from ifcopenshell.util.mvd_info import MvdInfo, LARK_AVAILABLE
-from lark.exceptions import UnexpectedCharacters, UnexpectedEOF, UnexpectedToken
-
 
 if TYPE_CHECKING:
     import ifcopenshell.util.schema
@@ -211,106 +209,6 @@ NO_HEADER = ifcopenshell_wrapper.file_open_status.NO_HEADER
 UNSUPPORTED_SCHEMA = ifcopenshell_wrapper.file_open_status.UNSUPPORTED_SCHEMA
 INVALID_SYNTAX = ifcopenshell_wrapper.file_open_status.INVALID_SYNTAX
 
-mvd_grammar = r'''
-    start: entry+
-
-    entry: "ViewDefinition" "[" simple_value_list "]"   -> view_definition
-         | "Comment" "[" comment_text "]" -> comment
-         | GENERIC_KEYWORD "[" value_list_set "]" -> dynamic_option
-
-    %declare COMMENT_TEXT  // Ensure Lark treats it with higher priority
-
-    GENERIC_KEYWORD: /[A-Za-z0-9_]+/
-    
-    simple_value_list: value ("," value)*
-    
-    value_list_set: value_set (";" value_set)*
-
-    value_set: set_name ":" simple_value_list
-    
-    set_name: /[A-Za-z0-9_]+/
-    
-    value: /[A-Za-z0-9 _\.-]+/
-    
-    comment_text: /[^\[\]]+/  // Free text inside COMMENT brackets
-
-    %import common.WS
-    %ignore WS
-'''
-
-parser = Lark(mvd_grammar, parser='lalr')
-class DescriptionTransform(Transformer):
-    def __init__(self):
-        self.mvd = []
-        self.keywords = set()
-        self.comments = ""
-        self.exchangerequirement = ""
-        self.option = ''
-
-
-    def view_definition(self, args):
-        self.keywords.add('mvd')  
-        self.mvd.extend(args[0])  
-
-
-    def dynamic_option(self, args):
-        """
-        e.g. in case of 'Remark' as optional keyword in the description
-        The value can be retrieved through DescriptionTransform.remark
-        """
-        key = str(args[0]).lower()
-        attr_name = f"{key}"
-        if attr_name not in self.keywords:
-            setattr(self, attr_name, {})
-            self.keywords.add(attr_name)
-        dynamic_dict = getattr(self, attr_name)
-        for value_set in args[1]:
-            set_name, *values = value_set
-            dynamic_dict[set_name] = values if len(values) > 1 else values[0]
-
-
-    def comment(self, args):
-        self.keywords.add('comment')
-        self.comments = " ".join(str(child) for child in args[0].children).strip()
-
-    def simple_value_list(self, args):
-        return [str(arg) for arg in args]
-
-    def value_list_set(self, args):
-        return args
-
-    def value_set(self, args):
-        return [str(args[0])] + args[1]
-
-    def value(self, args):
-        return str(args[0])
-
-    def set_name(self, args):
-        return str(args[0])
-    
-    @property 
-    def other_keywords(self):
-        """"
-        The predefined keywords are 'ViewDefinition', 'Option', 'Comment', 'ExchangeRequirement' and 'Option'
-        Keywords in the description not from this lists are returned
-        """
-        return {k for k in self.keywords if k not in {'mvd', 'comment', 'exchangerequirement', 'option'}}
-
-    
-def parse_mvd(description):
-    text = ' '.join(description)
-    parser = Lark(mvd_grammar, parser='lalr')
-    parsed_description = DescriptionTransform()
-    try:
-        if not text:
-            parsed_description.mvd = None
-            return parsed_description
-        parse_tree = parser.parse(text)
-        parsed_description.transform(parse_tree)
-    except (UnexpectedCharacters, UnexpectedEOF, UnexpectedToken) as e:
-        parsed_description.mvd = None
-    return parsed_description
-
 class file:
     """Base class for containing IFC files.
 
@@ -409,7 +307,6 @@ class file:
         import weakref
 
         file_dict[self.file_pointer()] = weakref.ref(self)
-        self.parsed_description = parse_mvd(self.wrapped_data.header.file_description.description)
 
     def __del__(self) -> None:
         # Avoid infinite recursion if file is failed to initialize
@@ -569,68 +466,16 @@ class file:
             number = re.search(prefix + r"(\d)", schema)
             version.append(int(number.group(1)) if number else 0)
         return tuple(version)
-    
-    @property 
-    def mvd(self) -> str:
-        """
-        View Definition supported by the exporting application that is reflected in the IFC file
-        For example: 
-        “CoordinationView”
-        | “PresentationView”
-        | “StructuralAnalysisView”
-        | “FMHandOverView”
-        | “QuantityTakeOffAddOnView”
-        | “SpaceBoundary1stLevelAddOnView”
-        | “SpaceBoundary2ndLevelAddOnView”
-        """
-        return ','.join(self.parsed_description.mvd)
-    
-    @property 
-    def mvd_comments(self) -> str:
-        """
-        For example; 'Comment [This
-        export contains Boolean Operation geometry that may not be fully
-        supported by other application]'
         
-        f.mvd_comments
-        'This export contains Boolean Operation geometry that may not be fully supported by other application'
-        """
-        return str(self.parsed_description.comments)
-    
-    @property
-    def mvd_exchange_requirements(self) -> str:
-        return str(self.parsed_description.exchangerequirement)
-    
-    @property
-    def mvd_options(self) -> str:
-        """
-        Option being used by the exporting application for e.g. quality control and debugging
-        a. this is an optional field providing informal information, the values for the Option keyword
-        reflect the export settings of the exporting software application, those settings may be
-        specific to the exporting software
-        For example: 
-        > "{'ExcludedObjects': [' Stair', ' Ramp', ' Space'], 'SplitLevel': ' On'}"
-        """
-        return str(self.parsed_description.option)
-    
     @property 
-    def mvd_keywords(self) -> str:
+    def mvd(self):
-        """
+        if not LARK_AVAILABLE:
-        Returns all keywords from description, e.g. 
+            return None
-        f.mvd_keywords
+        file_description = self.wrapped_data.header.file_description
-        "{'exchangerequirement', 'mvd', 'option', 'comment', 'remark'}"_
+        return MvdInfo(
-        """
+            get_description=lambda: file_description.description, 
-        return str(self.parsed_description.keywords)
+            set_description=lambda d: setattr(file_description, "description", tuple(d))
-    
+        )
-    @property
-    def mvd_optional_keyword_fields(self) -> str:
-        """"
-        Returns fields from keywords other than 'ViewDefinition', 'Option', 'Comment' and 'ExchangeRequirement'.
-        For example, in case of 
-        'REMARK [SomeKey: SomeValue; AnotherKey: AnotherValue]'
-        file.mvd_optional_keywords_fields == "{'remark': {'SomeKey': ' SomeValue', 'AnotherKey': ' AnotherValue'}}"
-        """
-        return str({kw: getattr(self.parsed_description, kw) for kw in self.parsed_description.other_keywords})
 
     def __getattr__(self, attr) -> Union[Any, Callable[..., ifcopenshell.entity_instance]]:
         if attr[0:6] == "create":

src/ifcopenshell-python/ifcopenshell/util/mvd_info.py

@@ -0,0 +1,310 @@
+try:
+    from lark import Lark, Transformer
+    from lark.exceptions import UnexpectedCharacters, UnexpectedEOF, UnexpectedToken
+    LARK_AVAILABLE = True
+except ImportError:
+    LARK_AVAILABLE = False
+
+from typing import Callable
+import re
+
+if LARK_AVAILABLE:
+    mvd_grammar = r'''
+        start: entry+
+
+        entry: "ViewDefinition" "[" simple_value_list "]"   -> view_definition
+            | "Comment" "[" simple_value_list "]" -> comment
+            | "ExchangeRequirement" "[" other_keyword "]" -> exchangerequirement
+            | "Option" "[" other_keyword "]" -> option
+            | GENERIC_KEYWORD "[" dynamic_option_word "]" -> dynamic_option
+
+        GENERIC_KEYWORD: /[A-Za-z0-9_]+/
+
+        simple_value_list: value ("," value)*
+
+        value_list_set: value_set (";" value_set)*
+
+        value_set: set_name ":" simple_value_list
+
+        set_name: /[A-Za-z0-9_]+/
+
+        value: /[A-Za-z0-9 _\.-]+/
+
+        other_keyword: /[^\[\]]+/  
+        
+        dynamic_option_word: /[^\[\]]+/ 
+
+        %import common.WS
+        %ignore WS
+    '''
+
+    parser = Lark(mvd_grammar, parser='lalr')
+
+    class DescriptionTransform(Transformer):
+        def __init__(self):
+            self.view_definitions = []
+            self.keywords = set()
+            self.comments = ""
+            self.exchange_requirements = ""
+            self.options = ""
+            self._dynamic = {}
+
+        def view_definition(self, args):
+            self.keywords.add('view_definitions')
+            self.view_definitions.extend(args[0])
+
+        def store_text_attribute(self, args, keyword):
+            self.keywords.add(keyword)
+            setattr(self, keyword, " ".join(" ".join(str(child) for child in args[0].children).split()))
+
+        def comment(self, args):
+            self.keywords.add("comments")
+            self.comments = args[0] if len(args[0]) > 1 else args[0][0]
+
+        def exchangerequirement(self, args):
+            self.store_text_attribute(args, "exchange_requirements")
+
+        def option(self, args):
+            if v := parse_semicolon_separated_kv(" ".join(" ".join(str(child) for child in args[0].children).split())):
+                setattr(self, 'options', v)
+            else:
+                self.store_text_attribute(args, "options")
+
+        def dynamic_option(self, args):
+            try:
+                original_keyword = str(args[0])  
+                key = original_keyword.lower()   
+                raw_text = args[1].children[0].value
+                parsed_value = parse_semicolon_separated_kv(raw_text)
+                self._dynamic[key] = (parsed_value, original_keyword)  
+                self.keywords.add(key)
+                setattr(self, key, parsed_value)
+            except Exception:
+                setattr(self, key, None)
+
+        def simple_value_list(self, args):
+            return [str(arg) for arg in args]
+
+        def value_list_set(self, args):
+            return args
+
+        def value_set(self, args):
+            return [str(args[0])] + args[1]
+
+        def value(self, args):
+            return str(args[0])
+
+        def set_name(self, args):
+            return str(args[0])
+
+    def parse_mvd(description):
+        text = ' '.join(description)
+        parsed_description = DescriptionTransform()
+        try:
+            if not text:
+                parsed_description.view_definitions = None
+                return parsed_description
+            parse_tree = parser.parse(text)
+            parsed_description.transform(parse_tree)
+        except (UnexpectedCharacters, UnexpectedEOF, UnexpectedToken):
+            parsed_description.view_definitions = None
+        return parsed_description
+
+    def parse_semicolon_separated_kv(text: str) -> dict[str, str | list[str]] | None:
+        if not re.search(r'\w+\s*:\s*[^:]+', text):
+            return None
+        result = {}
+        try:
+            pairs = text.split(';')
+            for pair in pairs:
+                if ':' in pair:
+                    key, value = pair.split(':', 1)
+                    key = key.strip()
+                    values = [v.strip() for v in value.split(',')]
+                    result[key] = values[0] if len(values) == 1 else values
+            return result
+        except Exception:
+            return None
+else:
+    def parse_mvd(description):
+        return None
+
+
+class MvdInfo:
+    def __init__(self, get_description: Callable[[], list[str]], set_description: Callable[[list[str]], None]):
+        self._get_description = get_description
+        self._set_description = set_description
+        self._parsed = None
+
+    def _ensure_parsed(self):
+        if not LARK_AVAILABLE:
+            return
+        if self._parsed is None:
+            self._parsed = parse_mvd(self.description)
+
+    @property
+    def description(self) -> list[str]:
+        return self._get_description()
+
+    @description.setter
+    def description(self, new_description: list[str]):
+        self._set_description(new_description)
+        self._parsed = None
+
+    @property
+    def view_definitions(self):
+        self._ensure_parsed()
+        return ', '.join(' '.join(item.split()) for item in self._parsed.view_definitions) if self._parsed else None
+
+    @view_definitions.setter
+    def view_definitions(self, new_value: str):
+        self._update_keyword("ViewDefinition", new_value)
+
+    @property
+    def comments(self):
+        self._ensure_parsed()
+        comments = self._parsed.comments
+        comment_list = comments if isinstance(comments, list) else [comments] if comments else []
+        return AutoCommitList(
+            comment_list,
+            callback=lambda val: self._update_keyword("Comment", val),
+            formatter=lambda lst: ", ".join(str(i) for i in lst)
+        )
+
+    @comments.setter
+    def comments(self, new_value: str | list[str]):
+        if isinstance(new_value, list):
+            value = ", ".join(new_value)
+        else:
+            value = str(new_value)
+        self._update_keyword("Comment", value)
+
+    @property
+    def exchange_requirements(self):
+        self._ensure_parsed()
+        return self._parsed.exchange_requirements if self._parsed else None
+
+    @exchange_requirements.setter
+    def exchange_requirements(self, new_value: str):
+        self._update_keyword("ExchangeRequirement", new_value)
+
+    @property
+    def options(self):
+        self._ensure_parsed()
+        if isinstance(self._parsed.options, dict):
+            return DictionaryHandler(self._parsed.options, self, "Option")
+        return self._parsed.options if self._parsed else None
+
+    @options.setter
+    def options(self, new_value: str):
+        self._update_keyword("Option", new_value)
+
+    @property
+    def keywords(self):
+        self._ensure_parsed()
+        return self._parsed.keywords if self._parsed else set()
+
+    def _update_keyword(self, keyword: str, new_value: str):
+        updated = False
+        new_line = f"{keyword} [{new_value}]"
+        lines = []
+        for line in self.description:
+            if line.strip().startswith(f"{keyword} ["):
+                lines.append(new_line)
+                updated = True
+            else:
+                lines.append(line)
+        if not updated:
+            lines.append(new_line)
+        self.description = lines
+
+    def __getattr__(self, name):
+        self._ensure_parsed()
+        if hasattr(self._parsed, '_dynamic'):
+            name_lc = name.lower()
+            if name_lc in self._parsed._dynamic:
+                value, original_keyword = self._parsed._dynamic[name_lc]
+                return DictionaryHandler(value, self, original_keyword)
+        raise AttributeError(f"'MvdInfo' object has no attribute '{name}'")
+
+    def __dir__(self):
+        base = super().__dir__()
+        if self._parsed and hasattr(self._parsed, '_dynamic'):
+            return base + [kw for _, kw in self._parsed._dynamic.values()]
+        return base
+
+
+class DictionaryHandler(dict):
+    def __init__(self, initial_data, mvdinfo, keyword):
+        super().__init__()
+        self._mvdinfo = mvdinfo
+        self._keyword = keyword
+        for k, v in initial_data.items():
+            if isinstance(v, list):
+                super().__setitem__(k, AutoCommitList(v, self._commit))
+            else:
+                super().__setitem__(k, v)
+
+    def _commit(self):
+        new_value = "; ".join(
+            f"{k}: {', '.join(v) if isinstance(v, list) else v}"
+            for k, v in self.items()
+        )
+        self._mvdinfo._update_keyword(self._keyword, new_value)
+
+    def __setitem__(self, key, value):
+        if isinstance(value, list):
+            value = AutoCommitList(value, self._commit)
+        super().__setitem__(key, value)
+        self._commit()
+
+    def __delitem__(self, key):
+        super().__delitem__(key)
+        self._commit()
+
+
+class AutoCommitList(list):
+    "ensures keyword attributes are written back to ifcopenshell.file.header"
+    def __init__(self, iterable, callback, formatter=None):
+        super().__init__(iterable)
+        self._callback = callback
+        self._formatter = formatter  
+
+    def _commit(self):
+        if self._formatter:
+            self._callback(self._formatter(self))
+        else:
+            self._callback()
+
+    def append(self, item):
+        super().append(item)
+        self._commit()
+
+    def extend(self, iterable):
+        super().extend(iterable)
+        self._commit()
+
+    def insert(self, index, item):
+        super().insert(index, item)
+        self._commit()
+
+    def remove(self, item):
+        super().remove(item)
+        self._commit()
+
+    def pop(self, index=-1):
+        item = super().pop(index)
+        self._commit()
+        return item
+
+    def clear(self):
+        super().clear()
+        self._commit()
+
+    def __setitem__(self, index, value):
+        super().__setitem__(index, value)
+        self._commit()
+
+    def __delitem__(self, index):
+        super().__delitem__(index)
+        self._commit()

src/ifcopenshell-python/test/fixtures/mvd_parsing/contains_comment.ifc

@@ -0,0 +1,30 @@
+ISO-10303-21;
+HEADER;
+FILE_DESCRIPTION(('ViewDefinition [ReferenceView_V1.2]', 'Comment [Any]'),'2;1');
+FILE_NAME('Header.ifc','2025-02-13T15:58:45',('tricott'),('Trimble Inc.'),'TrimBimToIFC rel. 4.0.2','Trimble Inc. - SketchUp - 2025.0','IFC4 model');
+FILE_SCHEMA(('IFC4'));
+ENDSEC;
+DATA;
+#1=IFCPERSON($,$,'',$,$,$,$,$);
+#2=IFCORGANIZATION($,'',$,$,$);
+#3=IFCPERSONANDORGANIZATION(#1,#2,$);
+#4=IFCAPPLICATION(#2,'v0.7.0-6c9e130ca','IfcOpenShell-v0.7.0-6c9e130ca','');
+#5=IFCOWNERHISTORY(#3,#4,$,.NOTDEFINED.,$,#3,#4,1700419055);
+#6=IFCDIRECTION((1.,0.,0.));
+#7=IFCDIRECTION((0.,0.,1.));
+#8=IFCCARTESIANPOINT((0.,0.,0.));
+#9=IFCAXIS2PLACEMENT3D(#8,#7,#6);
+#10=IFCDIRECTION((0.,1.));
+#11=IFCGEOMETRICREPRESENTATIONCONTEXT($,'Model',3,1.E-05,#9,#10);
+#12=IFCDIMENSIONALEXPONENTS(0,0,0,0,0,0,0);
+#13=IFCSIUNIT(*,.LENGTHUNIT.,$,.METRE.);
+#14=IFCSIUNIT(*,.AREAUNIT.,$,.SQUARE_METRE.);
+#15=IFCSIUNIT(*,.VOLUMEUNIT.,$,.CUBIC_METRE.);
+#16=IFCSIUNIT(*,.PLANEANGLEUNIT.,$,.RADIAN.);
+#17=IFCMEASUREWITHUNIT(IFCPLANEANGLEMEASURE(0.017453292519943295),#16);
+#18=IFCCONVERSIONBASEDUNIT(#12,.PLANEANGLEUNIT.,'DEGREE',#17);
+#19=IFCUNITASSIGNMENT((#13,#14,#15,#18));
+#20=IFCPROJECT('0iDmeiiLP3AOllitM2Favn',#5,'',$,$,$,$,(#11),#19);
+#21=IFCSITE('3rg2jGkIH10RFhrQsGZKRk',#5,$,$,$,$,$,$,$,$,$,$,$,$);
+ENDSEC;
+END-ISO-10303-21;

src/ifcopenshell-python/test/fixtures/mvd_parsing/contains_exchange_requirement.ifc

@@ -0,0 +1,30 @@
+ISO-10303-21;
+HEADER;
+FILE_DESCRIPTION(('ViewDefinition [ReferenceView_V1.2]', 'ExchangeRequirement [Any]'),'2;1');
+FILE_NAME('Header.ifc','2025-02-13T15:58:45',('tricott'),('Trimble Inc.'),'TrimBimToIFC rel. 4.0.2','Trimble Inc. - SketchUp - 2025.0','IFC4 model');
+FILE_SCHEMA(('IFC4'));
+ENDSEC;
+DATA;
+#1=IFCPERSON($,$,'',$,$,$,$,$);
+#2=IFCORGANIZATION($,'',$,$,$);
+#3=IFCPERSONANDORGANIZATION(#1,#2,$);
+#4=IFCAPPLICATION(#2,'v0.7.0-6c9e130ca','IfcOpenShell-v0.7.0-6c9e130ca','');
+#5=IFCOWNERHISTORY(#3,#4,$,.NOTDEFINED.,$,#3,#4,1700419055);
+#6=IFCDIRECTION((1.,0.,0.));
+#7=IFCDIRECTION((0.,0.,1.));
+#8=IFCCARTESIANPOINT((0.,0.,0.));
+#9=IFCAXIS2PLACEMENT3D(#8,#7,#6);
+#10=IFCDIRECTION((0.,1.));
+#11=IFCGEOMETRICREPRESENTATIONCONTEXT($,'Model',3,1.E-05,#9,#10);
+#12=IFCDIMENSIONALEXPONENTS(0,0,0,0,0,0,0);
+#13=IFCSIUNIT(*,.LENGTHUNIT.,$,.METRE.);
+#14=IFCSIUNIT(*,.AREAUNIT.,$,.SQUARE_METRE.);
+#15=IFCSIUNIT(*,.VOLUMEUNIT.,$,.CUBIC_METRE.);
+#16=IFCSIUNIT(*,.PLANEANGLEUNIT.,$,.RADIAN.);
+#17=IFCMEASUREWITHUNIT(IFCPLANEANGLEMEASURE(0.017453292519943295),#16);
+#18=IFCCONVERSIONBASEDUNIT(#12,.PLANEANGLEUNIT.,'DEGREE',#17);
+#19=IFCUNITASSIGNMENT((#13,#14,#15,#18));
+#20=IFCPROJECT('0iDmeiiLP3AOllitM2Favn',#5,'',$,$,$,$,(#11),#19);
+#21=IFCSITE('3rg2jGkIH10RFhrQsGZKRk',#5,$,$,$,$,$,$,$,$,$,$,$,$);
+ENDSEC;
+END-ISO-10303-21;

src/ifcopenshell-python/test/fixtures/mvd_parsing/contains_options.ifc

@@ -0,0 +1,30 @@
+ISO-10303-21;
+HEADER;
+FILE_DESCRIPTION(('ViewDefinition [ReferenceView_V1.2]', 'Option [Any]'),'2;1');
+FILE_NAME('Header.ifc','2025-02-13T15:58:45',('tricott'),('Trimble Inc.'),'TrimBimToIFC rel. 4.0.2','Trimble Inc. - SketchUp - 2025.0','IFC4 model');
+FILE_SCHEMA(('IFC4'));
+ENDSEC;
+DATA;
+#1=IFCPERSON($,$,'',$,$,$,$,$);
+#2=IFCORGANIZATION($,'',$,$,$);
+#3=IFCPERSONANDORGANIZATION(#1,#2,$);
+#4=IFCAPPLICATION(#2,'v0.7.0-6c9e130ca','IfcOpenShell-v0.7.0-6c9e130ca','');
+#5=IFCOWNERHISTORY(#3,#4,$,.NOTDEFINED.,$,#3,#4,1700419055);
+#6=IFCDIRECTION((1.,0.,0.));
+#7=IFCDIRECTION((0.,0.,1.));
+#8=IFCCARTESIANPOINT((0.,0.,0.));
+#9=IFCAXIS2PLACEMENT3D(#8,#7,#6);
+#10=IFCDIRECTION((0.,1.));
+#11=IFCGEOMETRICREPRESENTATIONCONTEXT($,'Model',3,1.E-05,#9,#10);
+#12=IFCDIMENSIONALEXPONENTS(0,0,0,0,0,0,0);
+#13=IFCSIUNIT(*,.LENGTHUNIT.,$,.METRE.);
+#14=IFCSIUNIT(*,.AREAUNIT.,$,.SQUARE_METRE.);
+#15=IFCSIUNIT(*,.VOLUMEUNIT.,$,.CUBIC_METRE.);
+#16=IFCSIUNIT(*,.PLANEANGLEUNIT.,$,.RADIAN.);
+#17=IFCMEASUREWITHUNIT(IFCPLANEANGLEMEASURE(0.017453292519943295),#16);
+#18=IFCCONVERSIONBASEDUNIT(#12,.PLANEANGLEUNIT.,'DEGREE',#17);
+#19=IFCUNITASSIGNMENT((#13,#14,#15,#18));
+#20=IFCPROJECT('0iDmeiiLP3AOllitM2Favn',#5,'',$,$,$,$,(#11),#19);
+#21=IFCSITE('3rg2jGkIH10RFhrQsGZKRk',#5,$,$,$,$,$,$,$,$,$,$,$,$);
+ENDSEC;
+END-ISO-10303-21;

src/ifcopenshell-python/test/fixtures/mvd_parsing/dynamic_fields.ifc

@@ -0,0 +1,30 @@
+ISO-10303-21;
+HEADER;
+FILE_DESCRIPTION(('ViewDefinition [ReferenceView_V1.2]', 'ViewDefinition [QuantityTakeOffAddOnView]', 'Option [ExcludedObjects: Stair, Ramp, Space; SplitLevel: On]', 'ExchangeRequirement [CustomRequirement: Value1, Value2]', 'Remark [SomeKey: SomeValue; AnotherKey: AnotherValue]', 'Comment [This is a free text comment, or a comma-separated list of items]'),'2;1');
+FILE_NAME('Header example2.ifc', '2022-09-16T10:35:07', ('Evandro Alfieri'), ('buildingSMART Int.'), 'IFC Motor 1.0', 'Company - Application - 26.0.0.0', 'none');
+FILE_SCHEMA(('IFC4X3_ADD2'));
+ENDSEC;
+DATA;
+#1=IFCPERSON($,$,'',$,$,$,$,$);
+#2=IFCORGANIZATION($,'',$,$,$);
+#3=IFCPERSONANDORGANIZATION(#1,#2,$);
+#4=IFCAPPLICATION(#2,'v0.7.0-6c9e130ca','IfcOpenShell-v0.7.0-6c9e130ca','');
+#5=IFCOWNERHISTORY(#3,#4,$,.NOTDEFINED.,$,#3,#4,1700419055);
+#6=IFCDIRECTION((1.,0.,0.));
+#7=IFCDIRECTION((0.,0.,1.));
+#8=IFCCARTESIANPOINT((0.,0.,0.));
+#9=IFCAXIS2PLACEMENT3D(#8,#7,#6);
+#10=IFCDIRECTION((0.,1.));
+#11=IFCGEOMETRICREPRESENTATIONCONTEXT($,'Model',3,1.E-05,#9,#10);
+#12=IFCDIMENSIONALEXPONENTS(0,0,0,0,0,0,0);
+#13=IFCSIUNIT(*,.LENGTHUNIT.,$,.METRE.);
+#14=IFCSIUNIT(*,.AREAUNIT.,$,.SQUARE_METRE.);
+#15=IFCSIUNIT(*,.VOLUMEUNIT.,$,.CUBIC_METRE.);
+#16=IFCSIUNIT(*,.PLANEANGLEUNIT.,$,.RADIAN.);
+#17=IFCMEASUREWITHUNIT(IFCPLANEANGLEMEASURE(0.017453292519943295),#16);
+#18=IFCCONVERSIONBASEDUNIT(#12,.PLANEANGLEUNIT.,'DEGREE',#17);
+#19=IFCUNITASSIGNMENT((#13,#14,#15,#18));
+#20=IFCPROJECT('0iDmeiiLP3AOllitM2Favn',#5,'',$,$,$,$,(#11),#19);
+#21=IFCSITE('3rg2jGkIH10RFhrQsGZKRk',#5,$,$,$,$,$,$,$,$,$,$,$,$);
+ENDSEC;
+END-ISO-10303-21;

src/ifcopenshell-python/test/fixtures/mvd_parsing/passing_header.ifc

@@ -0,0 +1,30 @@
+ISO-10303-21;
+HEADER;
+FILE_DESCRIPTION(('ViewDefinition [Alignment-basedView]'),'2;1');
+FILE_NAME('Header example2.ifc', '2022-09-16T10:35:07', ('Evandro Alfieri'), ('buildingSMART Int.'), 'IFC Motor 1.0', 'Company - Application - 26.0.0.0', 'none');
+FILE_SCHEMA(('IFC4X3_ADD2'));
+ENDSEC;
+DATA;
+#1=IFCPERSON($,$,'',$,$,$,$,$);
+#2=IFCORGANIZATION($,'',$,$,$);
+#3=IFCPERSONANDORGANIZATION(#1,#2,$);
+#4=IFCAPPLICATION(#2,'v0.7.0-6c9e130ca','IfcOpenShell-v0.7.0-6c9e130ca','');
+#5=IFCOWNERHISTORY(#3,#4,$,.NOTDEFINED.,$,#3,#4,1700419055);
+#6=IFCDIRECTION((1.,0.,0.));
+#7=IFCDIRECTION((0.,0.,1.));
+#8=IFCCARTESIANPOINT((0.,0.,0.));
+#9=IFCAXIS2PLACEMENT3D(#8,#7,#6);
+#10=IFCDIRECTION((0.,1.));
+#11=IFCGEOMETRICREPRESENTATIONCONTEXT($,'Model',3,1.E-05,#9,#10);
+#12=IFCDIMENSIONALEXPONENTS(0,0,0,0,0,0,0);
+#13=IFCSIUNIT(*,.LENGTHUNIT.,$,.METRE.);
+#14=IFCSIUNIT(*,.AREAUNIT.,$,.SQUARE_METRE.);
+#15=IFCSIUNIT(*,.VOLUMEUNIT.,$,.CUBIC_METRE.);
+#16=IFCSIUNIT(*,.PLANEANGLEUNIT.,$,.RADIAN.);
+#17=IFCMEASUREWITHUNIT(IFCPLANEANGLEMEASURE(0.017453292519943295),#16);
+#18=IFCCONVERSIONBASEDUNIT(#12,.PLANEANGLEUNIT.,'DEGREE',#17);
+#19=IFCUNITASSIGNMENT((#13,#14,#15,#18));
+#20=IFCPROJECT('0iDmeiiLP3AOllitM2Favn',#5,'',$,$,$,$,(#11),#19);
+#21=IFCSITE('3rg2jGkIH10RFhrQsGZKRk',#5,$,$,$,$,$,$,$,$,$,$,$,$);
+ENDSEC;
+END-ISO-10303-21;

src/ifcopenshell-python/test/fixtures/mvd_parsing/two_views.ifc

@@ -0,0 +1,30 @@
+ISO-10303-21;
+HEADER;
+FILE_DESCRIPTION(('ViewDefinition [CoordinationView_V2.0]', 'ViewDefinition[SpaceBoundaryAddonView]'),'2;1');
+FILE_NAME('Header example2.ifc', '2022-09-16T10:35:07', ('Evandro Alfieri'), ('buildingSMART Int.'), 'IFC Motor 1.0', 'Company - Application - 26.0.0.0', 'none');
+FILE_SCHEMA(('IFC2X3'));
+ENDSEC;
+DATA;
+#1=IFCPERSON($,$,'',$,$,$,$,$);
+#2=IFCORGANIZATION($,'',$,$,$);
+#3=IFCPERSONANDORGANIZATION(#1,#2,$);
+#4=IFCAPPLICATION(#2,'v0.7.0-6c9e130ca','IfcOpenShell-v0.7.0-6c9e130ca','');
+#5=IFCOWNERHISTORY(#3,#4,$,.NOTDEFINED.,$,#3,#4,1700419055);
+#6=IFCDIRECTION((1.,0.,0.));
+#7=IFCDIRECTION((0.,0.,1.));
+#8=IFCCARTESIANPOINT((0.,0.,0.));
+#9=IFCAXIS2PLACEMENT3D(#8,#7,#6);
+#10=IFCDIRECTION((0.,1.));
+#11=IFCGEOMETRICREPRESENTATIONCONTEXT($,'Model',3,1.E-05,#9,#10);
+#12=IFCDIMENSIONALEXPONENTS(0,0,0,0,0,0,0);
+#13=IFCSIUNIT(*,.LENGTHUNIT.,$,.METRE.);
+#14=IFCSIUNIT(*,.AREAUNIT.,$,.SQUARE_METRE.);
+#15=IFCSIUNIT(*,.VOLUMEUNIT.,$,.CUBIC_METRE.);
+#16=IFCSIUNIT(*,.PLANEANGLEUNIT.,$,.RADIAN.);
+#17=IFCMEASUREWITHUNIT(IFCPLANEANGLEMEASURE(0.017453292519943295),#16);
+#18=IFCCONVERSIONBASEDUNIT(#12,.PLANEANGLEUNIT.,'DEGREE',#17);
+#19=IFCUNITASSIGNMENT((#13,#14,#15,#18));
+#20=IFCPROJECT('0iDmeiiLP3AOllitM2Favn',#5,'',$,$,$,$,(#11),#19);
+#21=IFCSITE('3rg2jGkIH10RFhrQsGZKRk',#5,$,$,$,$,$,$,$,$,$,$,$,$);
+ENDSEC;
+END-ISO-10303-21;

src/ifcopenshell-python/test/test_mvd_info.py

@@ -0,0 +1,134 @@
+import os
+import pytest
+import ifcopenshell
+from ifcopenshell.util import mvd_info
+from ifcopenshell.util.mvd_info import parse_mvd
+
+
+@pytest.fixture
+def load_fixture():
+    base_dir = os.path.join(os.path.dirname(__file__), "fixtures", "mvd_parsing")
+    def _load(filename):
+        return ifcopenshell.open(os.path.join(base_dir, filename))
+    return _load
+
+
+class TestViewDefinition:
+    def test_single_view(self, load_fixture):
+        f = load_fixture("passing_header.ifc")
+        assert f.mvd.view_definitions == "Alignment-basedView"
+
+    def test_multiple_views(self, load_fixture):
+        f = load_fixture("two_views.ifc")
+        assert f.mvd.view_definitions == 'CoordinationView_V2.0, SpaceBoundaryAddonView'
+
+
+class TestExchangeRequirements:
+    def test_parsing(self, load_fixture):
+        f = load_fixture("contains_exchange_requirement.ifc")
+        parsed = parse_mvd(f.mvd.description)
+        assert parsed.exchange_requirements == 'Any'
+
+    def test_access_and_modification(self, load_fixture):
+        f = load_fixture("contains_exchange_requirement.ifc")
+        f.header.file_description.description = (
+            'ViewDefinition [Alignment-basedView]',
+            'ExchangeRequirement [SomethingElse]'
+        )
+        assert f.mvd.exchange_requirements == 'SomethingElse'
+        f.mvd.view_definitions = 'CoordinationView_V2.0'
+        assert f.mvd.view_definitions == 'CoordinationView_V2.0'
+
+
+class TestComments:
+    def test_read_and_append(self, load_fixture):
+        f = load_fixture("contains_comment.ifc")
+        assert f.mvd.comments == ['Any']
+        f.mvd.comments = ['SomethingElse']
+        assert f.mvd.comments == ['SomethingElse']
+        f.mvd.comments.append('AnotherComment')
+        assert f.mvd.comments == ['SomethingElse', ' AnotherComment']
+        assert f.mvd.description[1] == 'Comment [SomethingElse, AnotherComment]'
+    
+    def test_comment_list_modifications(self, load_fixture):
+        f = load_fixture("contains_comment.ifc")
+        f.mvd.comments = ''
+        f.mvd.comments.append('OnlyOne')
+        assert 'OnlyOne' in f.mvd.comments
+        
+        f.mvd.comments.insert(0, 'FirstOne')
+        f.mvd.comments[0] == 'FirstOne'
+
+        f.mvd.comments.pop()
+        assert f.mvd.comments[0] == 'FirstOne'
+        
+        del f.mvd.comments[0]
+        assert not f.mvd.comments
+
+
+class TestOptions:
+    def test_string_options(self, load_fixture):
+        f = load_fixture("contains_options.ifc")
+        assert f.mvd.options == 'Any'
+        assert 'options' in f.mvd.keywords
+
+
+class TestDynamicFields:
+    def test_options_modifications(self, load_fixture):
+        f = load_fixture("dynamic_fields.ifc")
+
+        f.mvd.options['ExcludedObjects'].append('Chair')
+        f.mvd.options['SplitLevel'] = 'Off'
+        f.mvd.options['OtherAttr'] = 'SomeValue'
+
+        assert f.mvd.description[2].startswith('Option [')
+        assert 'OtherAttr: SomeValue' in f.mvd.description[2]
+        assert f.mvd.description == f.header.file_description.description
+
+    def test_remark_editing(self, load_fixture):
+        f = load_fixture("dynamic_fields.ifc")
+        assert f.mvd.remark == {'SomeKey': 'SomeValue', 'AnotherKey': 'AnotherValue'}
+        f.mvd.remark['AnotherKey'] = 'SometingElse'
+        f.mvd.remark['IncludedObjects'] = ['Floor', 'Roof']
+        assert f.mvd.remark['AnotherKey'] == 'SometingElse'
+        assert f.mvd.remark['IncludedObjects'] == ['Floor', 'Roof']
+        assert 'remark' in f.mvd.keywords
+    
+    def test_custom_dict_behavior(self, load_fixture):
+        f = load_fixture("dynamic_fields.ifc")
+        
+        # delete
+        del f.mvd.options['SplitLevel']
+        assert not f.mvd.options.get('SplitLevel')
+        
+        # keys, values, items 
+        assert set(f.mvd.remark.keys()) == {'SomeKey', 'AnotherKey'}
+        assert 'SomeValue' in f.mvd.remark.values()
+        assert ('SomeKey', 'SomeValue') in f.mvd.remark.items()
+        
+        # containment
+        assert 'SomeKey' in f.mvd.remark
+        assert 'MissingKey' not in f.mvd.remark
+
+
+class TestKeywords:
+    @pytest.mark.parametrize("filename, expected_keywords", [
+        ("contains_comment.ifc", {"view_definitions", "comments"}),
+        ("contains_exchange_requirement.ifc", {"view_definitions", "exchange_requirements"}),
+        ("contains_options.ifc", {"view_definitions", "options"}),
+        ("dynamic_fields.ifc", {"view_definitions", "exchange_requirements", "comments", "remark"})
+    ])
+    def test_keywords_present(self, load_fixture, filename, expected_keywords):
+        f = load_fixture(filename)
+        assert f.mvd.keywords == expected_keywords
+
+
+class TestFallbackBehavior:
+    def test_parse_mvd_fallback(self, monkeypatch):
+        monkeypatch.setattr(mvd_info, "LARK_AVAILABLE", False)
+        mvd = mvd_info.MvdInfo(
+            get_description=lambda: ["ViewDefinition [ShouldNotParse]"],
+            set_description=lambda d: None
+        )
+        assert mvd.view_definitions is None
+        assert mvd.keywords == set()