[Modular] Consolidate load_default_components into load_components (#12217)

* update

* Apply style fixes

* update

* update

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

src/diffusers/modular_pipelines/modular_pipeline.py

@@ -1418,7 +1418,7 @@ class LoopSequentialPipelineBlocks(ModularPipelineBlocks):
 # YiYi TODO:
 # 1. look into the serialization of modular_model_index.json, make sure the items are properly ordered like model_index.json (currently a mess)
 # 2. do we need ConfigSpec? the are basically just key/val kwargs
-# 3. imnprove docstring and potentially add validator for methods where we accpet kwargs to be passed to from_pretrained/save_pretrained/load_default_components(), load_components()
+# 3. imnprove docstring and potentially add validator for methods where we accpet kwargs to be passed to from_pretrained/save_pretrained/load_components()
 class ModularPipeline(ConfigMixin, PushToHubMixin):
     """
     Base class for all Modular pipelines.
@@ -1488,7 +1488,7 @@ class ModularPipeline(ConfigMixin, PushToHubMixin):
             - Components with default_creation_method="from_config" are created immediately, its specs are not included
               in config dict and will not be saved in `modular_model_index.json`
             - Components with default_creation_method="from_pretrained" are set to None and can be loaded later with
-              `load_default_components()`/`load_components()`
+              `load_components()` (with or without specific component names)
             - The pipeline's config dict is populated with component specs (only for from_pretrained components) and
               config values, which will be saved as `modular_model_index.json` during `save_pretrained`
             - The pipeline's config dict is also used to store the pipeline blocks's class name, which will be saved as
@@ -1603,20 +1603,6 @@ class ModularPipeline(ConfigMixin, PushToHubMixin):
             params[input_param.name] = input_param.default
         return params
 
-    def load_default_components(self, **kwargs):
-        """
-        Load from_pretrained components using the loading specs in the config dict.
-
-        Args:
-            **kwargs: Additional arguments passed to `from_pretrained` method, e.g. torch_dtype, cache_dir, etc.
-        """
-        names = [
-            name
-            for name in self._component_specs.keys()
-            if self._component_specs[name].default_creation_method == "from_pretrained"
-        ]
-        self.load_components(names=names, **kwargs)
-
     @classmethod
     @validate_hf_hub_args
     def from_pretrained(
@@ -1770,8 +1756,8 @@ class ModularPipeline(ConfigMixin, PushToHubMixin):
            - non from_pretrained components are created during __init__ and registered as the object itself
         - Components are updated with the `update_components()` method: e.g. loader.update_components(unet=unet) or
           loader.update_components(guider=guider_spec)
-        - (from_pretrained) Components are loaded with the `load_default_components()` method: e.g.
-          loader.load_default_components(names=["unet"])
+        - (from_pretrained) Components are loaded with the `load_components()` method: e.g.
+          loader.load_components(names=["unet"]) or loader.load_components() to load all default components
 
         Args:
             **kwargs: Keyword arguments where keys are component names and values are component objects.
@@ -2097,13 +2083,14 @@ class ModularPipeline(ConfigMixin, PushToHubMixin):
         self.register_to_config(**config_to_register)
 
     # YiYi TODO: support map for additional from_pretrained kwargs
-    # YiYi/Dhruv TODO: consolidate load_components and load_default_components?
-    def load_components(self, names: Union[List[str], str], **kwargs):
+    def load_components(self, names: Optional[Union[List[str], str]] = None, **kwargs):
         """
         Load selected components from specs.
 
         Args:
-            names: List of component names to load; by default will not load any components
+            names: List of component names to load. If None, will load all components with
+                   default_creation_method == "from_pretrained". If provided as a list or string, will load only the
+                   specified components.
             **kwargs: additional kwargs to be passed to `from_pretrained()`.Can be:
              - a single value to be applied to all components to be loaded, e.g. torch_dtype=torch.bfloat16
              - a dict, e.g. torch_dtype={"unet": torch.bfloat16, "default": torch.float32}
@@ -2111,7 +2098,13 @@ class ModularPipeline(ConfigMixin, PushToHubMixin):
                `variant`, `revision`, etc.
         """
 
-        if isinstance(names, str):
+        if names is None:
+            names = [
+                name
+                for name in self._component_specs.keys()
+                if self._component_specs[name].default_creation_method == "from_pretrained"
+            ]
+        elif isinstance(names, str):
             names = [names]
         elif not isinstance(names, list):
             raise ValueError(f"Invalid type for names: {type(names)}")