Feature/lazy loading (#39)

* Lazy loading for parts. It also enables aliases.

* Added a test case for part aliases

examples/part_cadquery_primitive/partcad.yaml

@@ -3,6 +3,7 @@ parts:
   cube:
     type: cadquery
     desc: This is a cube from examples
+    aliases: ["box"]
   cylinder:
     type: cadquery
     path: cylinder.py

src/partcad/assembly.py

@@ -81,9 +81,6 @@ def get_shape(self):
             self.shape = shape.wrapped
         return copy.copy(self.shape)
 
-    def get_wrapped(self):
-        return self.get_shape()
-
     def _render_txt_real(self, file):
         for child in self.children:
             child._render_txt_real(file)

src/partcad/part.py

@@ -17,15 +17,17 @@
 
 
 class Part(shape.Shape):
-    def __init__(self, name=None, config={}, shape=None):
+    def __init__(self, name=None, path=None, config={}, shape=None):
         if name is None:
             name = "part" + "".join(
                 random.choices(string.ascii_uppercase + string.digits, k=8)
             )
+        if path is None:
+            path = name
         super().__init__(name)
 
         self.config = config
-        self.path = config["path"]
+        self.path = path
         self.shape = shape
 
         self.desc = None
@@ -49,6 +51,11 @@ def __init__(self, name=None, config={}, shape=None):
     def set_shape(self, shape):
         self.shape = shape
 
+    def get_shape(self):
+        if self.shape is None:
+            self.instantiate(self)
+        return self.shape
+
     def ref_inc(self):
         self.count += 1
 

src/partcad/part_factory.py

@@ -16,6 +16,7 @@ class PartFactory:
     def __init__(self, ctx, project, part_config, extension=""):
         self.ctx = ctx
         self.project = project
+        self.part_config = part_config
         self.name = part_config["name"]
 
         self.path = self.name + extension
@@ -34,7 +35,12 @@ def __init__(self, ctx, project, part_config, extension=""):
         part_config["path"] = self.path
 
     def _create(self, part_config):
-        self.part = p.Part(self.name, part_config)
+        self.part = p.Part(self.name, self.path, part_config)
 
-    def _save(self):
         self.project.parts[self.name] = self.part
+        if "aliases" in self.part_config and not self.part_config["aliases"] is None:
+            for alias in self.part_config["aliases"]:
+                # TODO(clairbee): test if this a copy or a reference
+                self.project.parts[alias] = self.part
+
+        self.part.instantiate = lambda part_self: self.instantiate(part_self)

src/partcad/part_factory_build123d.py

@@ -28,6 +28,7 @@ def __init__(self, ctx, project, part_config):
         # Complement the config object here if necessary
         self._create(part_config)
 
+    def instantiate(self, part):
         wrapper_path = wrapper.get("build123d.py")
 
         request = {"build_parameters": {}}
@@ -45,8 +46,7 @@ def __init__(self, ctx, project, part_config):
 
         if result["success"]:
             shape = result["shape"]
-            self.part.shape = shape
+            part.set_shape(shape)
         else:
             logging.error(result["exception"])
-
-        self._save()
+            raise Exception(result["exception"])

src/partcad/part_factory_cadquery.py

@@ -28,6 +28,7 @@ def __init__(self, ctx, project, part_config):
         # Complement the config object here if necessary
         self._create(part_config)
 
+    def instantiate(self, part):
         wrapper_path = wrapper.get("cadquery.py")
 
         request = {"build_parameters": {}}
@@ -45,8 +46,7 @@ def __init__(self, ctx, project, part_config):
 
         if result["success"]:
             shape = result["shape"]
-            self.part.shape = shape
+            part.set_shape(shape)
         else:
             logging.error(result["exception"])
-
-        self._save()
+            raise Exception(result["exception"])

src/partcad/part_factory_step.py

@@ -18,7 +18,6 @@ def __init__(self, ctx, project, part_config):
         # Complement the config object here if necessary
         self._create(part_config)
 
-        shape = cq.importers.importStep(self.path).val().wrapped
-        self.part.set_shape(shape)
-
-        self._save()
+    def instantiate(self, part):
+        shape = cq.importers.importStep(part.path).val().wrapped
+        part.set_shape(shape)

src/partcad/project.py

@@ -50,13 +50,16 @@ def __init__(self, ctx, path):
         else:
             self.desc = ""
 
+        self.init_parts()
+        self.init_assemblies()
+
     def get_part_config(self, part_name):
         if not part_name in self.part_configs:
             return None
         return self.part_configs[part_name]
 
-    def get_part(self, part_name):
-        if not part_name in self.parts:
+    def init_parts(self):
+        for part_name in self.part_configs:
             part_config = self.get_part_config(part_name)
 
             # Handle the case of the part being declared in the config
@@ -91,22 +94,19 @@ def get_part(self, part_name):
                 )
                 return None
 
-            # Since factories do not return status codes, we need to verify
-            # whether they have produced the expected product or not
-            # TODO(clairbee): reconsider returning status from the factories
-            if not part_name in self.parts:
-                logging.error("Failed to instantiate the part: %s" % part_config)
-                return None
-
+    def get_part(self, part_name):
+        if not part_name in self.parts:
+            logging.error("Part not found: %s" % part_name)
+            return None
         return self.parts[part_name]
 
     def get_assembly_config(self, assembly_name):
         if not assembly_name in self.assembly_configs:
             return None
         return self.assembly_configs[assembly_name]
 
-    def get_assembly(self, assembly_name):
-        if not assembly_name in self.assemblies:
+    def init_assemblies(self):
+        for assembly_name in self.assembly_configs:
             assembly_config = self.get_assembly_config(assembly_name)
 
             # Handle the case of the part being declared in the config
@@ -133,15 +133,10 @@ def get_assembly(self, assembly_name):
                 )
                 return None
 
-            # Since factories do not return status codes, we need to verify
-            # whether they have produced the expected product or not
-            # TODO(clairbee): reconsider returning status from the factories
-            if not assembly_name in self.assemblies:
-                logging.error(
-                    "Failed to instantiate the assembly: %s" % assembly_config
-                )
-                return None
-
+    def get_assembly(self, assembly_name):
+        if not assembly_name in self.assemblies:
+            logging.error("Assembly not found: %s" % assembly_name)
+            return None
         return self.assemblies[assembly_name]
 
     def render(self, parts=None, assemblies=None):

src/partcad/shape.py

@@ -29,7 +29,7 @@ def __init__(self, name):
         self.svg_url = None
 
     def get_wrapped(self):
-        return self.shape
+        return self.get_shape()
 
     def get_cadquery(self) -> cq.Shape:
         cq_solid = cq.Solid.makeBox(1, 1, 1)

tests/unit/test_part.py

@@ -30,13 +30,15 @@ def test_part_get_1():
     repo1 = ctx.get_project("this")
     bolt = repo1.get_part("bolt")
     assert bolt is not None
+    assert bolt.get_wrapped() is not None
 
 
 def test_part_get_2():
     """Load part from the context by the project and part names"""
     ctx = pc.Context("examples/part_step")
     bolt = ctx.get_part("bolt", "this")
     assert bolt is not None
+    assert bolt.get_wrapped() is not None
 
 
 def test_part_get_3():
@@ -45,38 +47,49 @@ def test_part_get_3():
     _ = pc.ProjectFactoryLocal(ctx, None, test_config_local)
     cylinder = ctx.get_part("cylinder", "primitive_local")
     assert cylinder is not None
+    assert cylinder.get_wrapped() is not None
 
 
 # Note: The below test fails if there are braking changes in the way parts are
 #       declared. Keep it this way so that the braking changes are conciously
 #       force pushed.
 def test_part_get_4():
     """Instantiate a project by a git import config and load a part"""
-    ctx = pc.Context()  # Emplty config
+    ctx = pc.Context()  # Empty config
     factory = pc.ProjectFactoryGit(ctx, None, test_config_git)
     assert factory.project.path.endswith(test_config_git["relPath"])
     cube = factory.project.get_part("cube")
     assert cube is not None
+    assert cube.get_wrapped() is not None
 
 
-def test_part_lazy_loading_1():
-    """Future test for lazy loading of geometry data"""
+def test_part_lazy_loading():
+    """Test for lazy loading of geometry data"""
     ctx = pc.Context()  # Empty config
     _ = pc.ProjectFactoryLocal(ctx, None, test_config_local)
     cylinder = ctx.get_part("cylinder", "primitive_local")
-    # TODO(clairbee): implement lazy loading
-    # assert cylinder.shape is None
-    # logo.build()
+    assert cylinder.shape is None
     assert cylinder.get_wrapped() is not None
 
 
+def test_part_aliases():
+    """Test for part aliases"""
+    ctx = pc.Context()  # Empty config
+    _ = pc.ProjectFactoryLocal(ctx, None, test_config_local)
+    # "box" is an alias for "cube"
+    box = ctx.get_part("box", "primitive_local")
+    assert box.shape is None
+    assert box.get_wrapped() is not None
+
+
 def test_part_example_cadquery_primitive():
     """Instantiate all parts from the example: part_cadquery_primitive"""
     ctx = pc.init("tests/partcad-examples.yaml")
     cube = ctx.get_part("cube", "example_part_cadquery_primitive")
     assert cube is not None
     cylinder = ctx.get_part("cylinder", "example_part_cadquery_primitive")
     assert cylinder is not None
+    assert cylinder.get_wrapped() is not None
 
 
 def test_part_example_cadquery_logo():
@@ -86,10 +99,12 @@ def test_part_example_cadquery_logo():
     assert bone is not None
     head_half = ctx.get_part("head_half", "example_part_cadquery_logo")
     assert head_half is not None
+    assert head_half.get_wrapped() is not None
 
 
 def test_part_example_build123d_primitive():
     """Instantiate all parts from the example: part_build123d_primitive"""
     ctx = pc.init("tests/partcad-examples.yaml")
     cube = ctx.get_part("cube", "example_part_build123d_primitive")
     assert cube is not None
+    assert cube.get_wrapped() is not None