Handle effect package path with class names

Author: einarf

demosys/effects/registry.py

@@ -31,7 +31,7 @@ def parse_package_string(path):
     if parts[-1][0].isupper():
         return ".".join(parts[:-1]), parts[-1]
 
-    return path
+    return path, ""
 
 
 class EffectRegistry:
@@ -79,6 +79,8 @@ def add_package(self, name):
 
         :param name: (str) The effect package to add
         """
+        name, cls_name = parse_package_string(name)
+
         if name in self.package_map:
             return
 
@@ -93,14 +95,39 @@ def add_package(self, name):
 
     def get_package(self, name) -> 'EffectPackage':
         """
-        Get a package by python path
+        Get a package by python path. Can also contain path to an effect.
+
+        Args:
+            name (str): Path to effect package or effect
+        
+        Returns:
+            The requested EffectPackage
+
+        Raises:
+            EffectError when no package is found
         """
+        name, cls_name = parse_package_string(name)
+
         try:
             return self.package_map[name]
         except KeyError:
             raise EffectError("No package '{}' registered".format(name))
 
-    def find_effect_class(self, class_name, package_name=None) -> Type[Effect]:
+    def find_effect_class(self, path) -> Type[Effect]:
+        """
+        Find an effect class by class name or full python path to class
+
+        Args:
+            path (str): effect class name or full python path to effect class
+        
+        Returns:
+            Effect class
+
+        Raises:
+            EffectError if no class is found
+        """
+        package_name, class_name = parse_package_string(path)
+
         if package_name:
             package = self.get_package(package_name)
             return package.find_effect_class(class_name, raise_for_error=True)

demosys/management/commands/runeffect.py

@@ -9,7 +9,7 @@ class Command(RunCommand):
     help = "Runs an effect"
 
     def add_arguments(self, parser):
-        parser.add_argument("effect_package", help="Name of the effect package")
+        parser.add_argument("effect_package", help="Python path to effect package or effect class")
 
     def handle(self, *args, **options):
         demosys.setup(

demosys/project/base.py

@@ -117,8 +117,7 @@ def create_effect(self, label: str, name: str, *args, **kwargs) -> Effect:
         Returns:
             The newly created Effect instance
         """
-        params = name.split('.')
-        effect_cls = effects.find_effect_class(params[-1], package_name=".".join(params[:-1]))
+        effect_cls = effects.find_effect_class(name)
         effect = effect_cls(*args, **kwargs)
         effect._label = label
 

demosys/project/default.py

@@ -1,5 +1,5 @@
 from demosys.project.base import BaseProject
-from demosys.effects.registry import effects
+from demosys.effects.registry import effects, parse_package_string
 
 
 class Project(BaseProject):
@@ -9,7 +9,9 @@ class Project(BaseProject):
     """
     def __init__(self, effect_package):
         super().__init__()
-        self.effect_packages = [effect_package]
+        self.path = effect_package
+        self.effect_package_name, self.effect_class_name = parse_package_string(effect_package)
+        self.effect_packages = [self.effect_package_name]
         self.effect = None
 
     def get_default_effect(self):
@@ -19,12 +21,9 @@ def create_resources(self):
         pass
 
     def create_effect_instances(self):
-        cls = self.get_runnable_effect()
-        self.effect = self.create_effect('default', cls.__name__)
+        cls = effects.find_effect_class(self.path)
+
+        if not cls.runnable:
+            raise ValueError("Effect doesn't have the runnable flag set:", self.path)
 
-    def get_runnable_effect(self):
-        """
-        Attempt to get a runnable effect in a package
-        """
-        runnable = effects.packages[0].runnable_effects()
-        return runnable[0]
+        self.effect = self.create_effect('default', cls.__name__)