Allow reading/writing step files to string

src/SWIG_files/wrapper/STEPCAFControl.i

@@ -1873,6 +1873,27 @@ Loads a file from stream and returns the read status. @param thename [in] auxili
 ") ReadStream;
 		IFSelect_ReturnStatus ReadStream(Standard_CString theName, std::istream & theIStream);
 
+		%feature("autodoc", "
+Parameters
+----------
+theName: str
+theIStream: str
+
+Return
+-------
+IFSelect_ReturnStatus
+
+Description
+-----------
+Loads a file from a string and returns the read status. @param thename [in] auxiliary file name @param src [in] the string to read and return read status.
+") ReadString;
+		%extend{
+		    IFSelect_ReturnStatus ReadString(Standard_CString theName, const std::string & src) {
+				std::stringstream s(src);
+				return self->ReadStream(theName, s);
+		    }
+		}
+
 		/****************** Reader ******************/
 		/**** md5 signature: c54201c04d6a5ca89c65eb2fb14b8396 ****/
 		%feature("compactdefaultargs") Reader;
@@ -2554,6 +2575,27 @@ Writes all the produced models into the stream. provided for use like single-fil
 ") WriteStream;
 		IFSelect_ReturnStatus WriteStream(std::ostream & theStream);
 
+		%feature("autodoc", "
+Return
+-------
+str
+
+Description
+-----------
+Writes all the produced models to a string and returns it. If full_precision is False, the default precision of std::stringstream is used which regularly causes rounding.
+") WriteString;
+		%extend{
+		    std::string WriteString(bool full_precision = true) {
+				std::stringstream s;
+				if(full_precision) {
+                    s.precision(17);
+                    s.setf(std::ios::scientific);
+				}
+				self->WriteStream(s);
+				return s.str();
+		    }
+		}
+
 		/****************** Writer ******************/
 		/**** md5 signature: 056d4f3221d283b7d58d92ddd5c40dd7 ****/
 		%feature("compactdefaultargs") Writer;

src/SWIG_files/wrapper/STEPCAFControl.pyi

@@ -163,6 +163,7 @@ class STEPCAFControl_Reader:
     @overload
     def Perform(self, filename: str, doc: TDocStd_Document, theProgress: Optional[Message_ProgressRange] = Message_ProgressRange()) -> bool: ...
     def ReadFile(self, theFileName: str) -> IFSelect_ReturnStatus: ...
+    def ReadString(self, theFilename: str, src: str) -> IFSelect_ReturnStatus: ...
     def Reader(self) -> STEPControl_Reader: ...
     def SetColorMode(self, colormode: bool) -> None: ...
     def SetGDTMode(self, gdtmode: bool) -> None: ...
@@ -212,6 +213,7 @@ class STEPCAFControl_Writer:
     @overload
     def Transfer(self, theLabelSeq: TDF_LabelSequence, theMode: Optional[STEPControl_StepModelType] = STEPControl_AsIs, theIsMulti: Optional[str] = 0, theProgress: Optional[Message_ProgressRange] = Message_ProgressRange()) -> bool: ...
     def Write(self, theFileName: str) -> IFSelect_ReturnStatus: ...
+    def WriteString(self, full_precision: bool = True) -> str: ...
     def Writer(self) -> STEPControl_Writer: ...
 
 # harray1 classes

test/core_ocaf_unittest.py

@@ -119,6 +119,67 @@ def test_read_step_file(self) -> None:
         a_shape = shape_tool.GetShape(label_shp)
         self.assertFalse(a_shape.IsNull())
 
+    def test_read_write_step_string(self) -> None:
+        """Writes a step file as a string and reads it back"""
+        ##### write
+
+        ### initialisation
+        doc = TDocStd_Document("pythonocc-doc")
+        self.assertTrue(doc is not None)
+
+        # Get root assembly
+        shape_tool = XCAFDoc_DocumentTool.ShapeTool(doc.Main())
+        colors = XCAFDoc_DocumentTool.ColorTool(doc.Main())
+        ### create the shape to export
+        test_shape = BRepPrimAPI_MakeBox(100.0, 100.0, 100.0).Shape()
+
+        ### add shape
+        shp_label = shape_tool.AddShape(test_shape)
+        ### set a color for this shape
+        r = 1.0
+        g = b = 0.5
+        red_color = Quantity_Color(r, g, b, Quantity_TypeOfColor.Quantity_TOC_RGB)
+        colors.SetColor(shp_label, red_color, XCAFDoc_ColorGen)
+        # write file
+        WS = XSControl_WorkSession()
+        writer = STEPCAFControl_Writer(WS, False)
+        writer.Transfer(doc, STEPControl_AsIs)
+        step_str = writer.WriteString()
+
+        ##### read
+
+        # create an handle to a document
+        doc = TDocStd_Document("pythonocc-doc")
+        # Get root assembly
+        shape_tool = XCAFDoc_DocumentTool.ShapeTool(doc.Main())
+        l_colors = XCAFDoc_DocumentTool.ColorTool(doc.Main())
+        step_reader = STEPCAFControl_Reader()
+        step_reader.SetColorMode(True)
+        step_reader.SetLayerMode(True)
+        step_reader.SetNameMode(True)
+        step_reader.SetMatMode(True)
+        status = step_reader.ReadString("myfile.step", step_str)
+        self.assertEqual(status, IFSelect_RetDone)
+        step_reader.Transfer(doc)
+
+        labels = TDF_LabelSequence()
+        color_labels = TDF_LabelSequence()
+
+        shape_tool.GetFreeShapes(labels)
+
+        self.assertEqual(labels.Length(), 1)
+        sub_shapes_labels = TDF_LabelSequence()
+        self.assertFalse(shape_tool.IsAssembly(labels.Value(1)))
+        shape_tool.GetSubShapes(labels.Value(1), sub_shapes_labels)
+        self.assertEqual(sub_shapes_labels.Length(), 0)
+
+        l_colors.GetColors(color_labels)
+        self.assertEqual(color_labels.Length(), 1)
+
+        label_shp = labels.Value(1)
+        a_shape = shape_tool.GetShape(label_shp)
+        self.assertFalse(a_shape.IsNull())
+
     def test_read_step_material(self) -> None:
         # create an handle to a document
         doc = TDocStd_Document("pythonocc-doc")