You can now unload a partially loaded project

src/blenderbim/blenderbim/bim/module/project/__init__.py

@@ -22,6 +22,7 @@ from . import ui, prop, operator
 classes = (
     operator.CreateProject,
     operator.LoadProject,
+    operator.UnloadProject,
     operator.LoadProjectElements,
     operator.SelectLibraryFile,
     operator.ChangeLibraryElement,

src/blenderbim/blenderbim/bim/module/project/operator.py

@@ -524,6 +524,18 @@ class LoadProject(bpy.types.Operator):
         return {"RUNNING_MODAL"}
 
 
+class UnloadProject(bpy.types.Operator):
+    bl_idname = "bim.unload_project"
+    bl_label = "Unload Project"
+    bl_options = {"REGISTER", "UNDO"}
+
+    def execute(self, context):
+        IfcStore.purge()
+        context.scene.BIMProperties.ifc_file = ""
+        context.scene.BIMProjectProperties.is_loading = False
+        return {"FINISHED"}
+
+
 class LoadProjectElements(bpy.types.Operator):
     bl_idname = "bim.load_project_elements"
     bl_label = "Load Project Elements"

src/blenderbim/blenderbim/bim/module/project/ui.py

@@ -56,8 +56,9 @@ class BIM_PT_project(Panel):
                 pprops,
                 "active_filter_category_index",
             )
-        row = self.layout.row()
+        row = self.layout.row(align=True)
         row.operator("bim.load_project_elements")
+        row.operator("bim.unload_project", text="", icon="CANCEL")
 
     def draw_project_ui(self, context):
         props = context.scene.BIMProperties

src/blenderbim/test/bim/bootstrap.py

@@ -129,6 +129,12 @@ def an_ifc_file_exists():
     return ifc
 
 
+def an_ifc_file_does_not_exist():
+    ifc = IfcStore.get_file()
+    if ifc:
+        assert False, "An IFC is available"
+
+
 def the_object_name_does_not_exist(name):
     assert bpy.data.objects.get(name) is None, "Object exists"
 
@@ -255,6 +261,7 @@ definitions = {
     'the object "(.*)" is in the collection "(.*)"': the_object_name_is_in_the_collection_collection,
     'the collection "(.*)" is in the collection "(.*)"': the_collection_name1_is_in_the_collection_name2,
     "an IFC file exists": an_ifc_file_exists,
+    "an IFC file does not exist": an_ifc_file_does_not_exist,
     'the object "(.*)" has a "(.*)" representation of "(.*)"': the_object_name_has_a_type_representation_of_context,
     'the object "(.*)" is placed in the collection "(.*)"': the_object_name_is_placed_in_the_collection_collection,
     'the object "(.*)" is contained in "(.*)"': the_object_name_is_contained_in_container_name,

src/blenderbim/test/bim/module/project/test_operator.py

@@ -94,3 +94,13 @@ class TestLoadProjectElements(test.bim.bootstrap.NewFile):
         And the object "IfcBuildingStorey/Level 1" does not exist
         And the object "IfcWall/Wall" does not exist
         """
+
+class TestUnloadProject(test.bim.bootstrap.NewFile):
+    @test.bim.bootstrap.scenario
+    def test_unloading_a_project(self):
+        return """
+        When I press "bim.load_project(filepath='{cwd}/test/files/basic.ifc')"
+        And I press "bim.unload_project"
+        Then an IFC file does not exist
+        And "scene.BIMProjectProperties.is_loading" is "False"
+        """