Prevent losing names of utilized components when loaded from config

docs/_src/api/api/pipelines.md

@@ -25,6 +25,18 @@ def root_node() -> Optional[str]
 
 Returns the root node of the pipeline's graph.
 
+<a id="base.Pipeline.components"></a>
+
+#### Pipeline.components
+
+```python
+@property
+def components() -> Dict[str, BaseComponent]
+```
+
+Returns all components used by this pipeline.
+Note that this also includes such components that are being utilized by other components only and are not being used as a pipeline node directly.
+
 <a id="base.Pipeline.to_code"></a>
 
 #### Pipeline.to\_code

haystack/nodes/base.py

@@ -119,15 +119,17 @@ def get_subclass(cls, component_type: str) -> Type[BaseComponent]:
         return subclass
 
     @classmethod
-    def _create_instance(cls, component_type: str, component_params: Dict[str, Any]):
+    def _create_instance(cls, component_type: str, component_params: Dict[str, Any], name: Optional[str] = None):
         """
         Returns an instance of the given subclass of BaseComponent.
 
         :param component_type: name of the component class to load.
         :param component_params: parameters to pass to the __init__() for the component.
+        :param name: name of the component instance
         """
         subclass = cls.get_subclass(component_type)
         instance = subclass(**component_params)
+        instance.name = name
         return instance
 
     @abstractmethod

haystack/pipelines/base.py

@@ -81,11 +81,28 @@ def root_node(self) -> Optional[str]:
 
     @property
     def components(self) -> Dict[str, BaseComponent]:
-        return {
-            name: attributes["component"]
-            for name, attributes in self.graph.nodes.items()
+        """
+        Returns all components used by this pipeline.
+        Note that this also includes such components that are being utilized by other components only and are not being used as a pipeline node directly.
+        """
+        node_components = [
+            attributes["component"]
+            for attributes in self.graph.nodes.values()
             if not isinstance(attributes["component"], RootNode)
-        }
+        ]
+        all_components = self._find_all_components(node_components)
+        return {component.name: component for component in all_components if component.name is not None}
+
+    def _find_all_components(self, components: List[BaseComponent]) -> Set[BaseComponent]:
+        """
+        Finds all components given the provided components.
+        Components are found by traversing the provided components and their utilized components.
+        """
+        distinct_components = set(components)
+        for component in components:
+            sub_components = self._find_all_components(component.utilized_components)
+            distinct_components.update(sub_components)
+        return distinct_components
 
     def to_code(
         self, pipeline_variable_name: str = "pipeline", generate_imports: bool = True, add_comment: bool = False
@@ -373,12 +390,17 @@ def add_node(self, component: BaseComponent, name: str, inputs: List[str]):
                 )
             self.graph = _init_pipeline_graph(root_node_name=candidate_roots[0])
 
-        component_definitions = get_component_definitions(pipeline_config=self.get_config())
-
-        # Check for duplicates before adding the definition
-        if name in component_definitions.keys():
+        # Check for duplicate names before adding the component
+        # Note that the very same component must be addable multiple times:
+        # E.g. for indexing pipelines it's common to add a retriever first and a document store afterwards.
+        # The document store is already being used by the retriever however.
+        # Thus the very same document store will be added twice, first as a subcomponent of the retriever and second as a first level node.
+        if name in self.components and self.components[name] != component:
             raise PipelineConfigError(f"A node named '{name}' is already in the pipeline. Choose another name.")
-        component_definitions[name] = component._component_config
+
+        component_definitions = get_component_definitions(pipeline_config=self.get_config())
+        component_definition = {"params": component.get_params(), "type": component.type}
+        component_definitions[name] = component_definition
 
         # Name any nested component before adding them
         component.name = name
@@ -1411,7 +1433,9 @@ def _load_or_get_component(cls, name: str, definitions: dict, components: dict):
                         value
                     ]  # substitute reference (string) with the component object.
 
-            component_instance = BaseComponent._create_instance(component_type, component_params)
+            component_instance = BaseComponent._create_instance(
+                component_type=component_type, component_params=component_params, name=name
+            )
             components[name] = component_instance
             return component_instance
 

haystack/pipelines/ray.py

@@ -333,6 +333,6 @@ def load_from_pipeline_config(pipeline_config: dict, component_name: str):
                 component_params[key] = _RayDeploymentWrapper.load_from_pipeline_config(pipeline_config, value)
 
         component_instance = BaseComponent._create_instance(
-            component_type=component_config["type"], component_params=component_params
+            component_type=component_config["type"], component_params=component_params, name=component_name
         )
         return component_instance

haystack/pipelines/utils.py

@@ -74,6 +74,7 @@ def generate_code(
         component_definitions=component_definitions,
         component_variable_names=component_variable_names,
         dependency_graph=component_dependency_graph,
+        pipeline_definition=pipeline_definition,
     )
     pipeline_code = _generate_pipeline_code(
         pipeline_definition=pipeline_definition,
@@ -109,7 +110,10 @@ def _generate_pipeline_code(
 
 
 def _generate_components_code(
-    component_definitions: Dict[str, Any], component_variable_names: Dict[str, str], dependency_graph: DiGraph
+    component_definitions: Dict[str, Any],
+    component_variable_names: Dict[str, str],
+    dependency_graph: DiGraph,
+    pipeline_definition: Dict[str, Any],
 ) -> str:
     code = ""
     declarations = {}
@@ -121,7 +125,11 @@ def _generate_components_code(
             for key, value in definition.get("params", {}).items()
         }
         init_args = ", ".join(f"{key}={value}" for key, value in param_value_dict.items())
-        declarations[name] = f"{variable_name} = {class_name}({init_args})"
+        declaration = f"{variable_name} = {class_name}({init_args})"
+        # set name of subcomponents explicitly if it's not the default name as it won't be set via Pipeline.add_node()
+        if name != class_name and name not in (node["name"] for node in pipeline_definition["nodes"]):
+            declaration = f'{declaration}\n{variable_name}.name = "{name}"'
+        declarations[name] = declaration
 
     ordered_components = nx.topological_sort(dependency_graph)
     ordered_declarations = [declarations[component] for component in ordered_components]

test/pipelines/test_pipeline.py

@@ -467,6 +467,7 @@ def test_generate_code_imports():
         "from haystack.pipelines import Pipeline\n"
         "\n"
         "document_store = ElasticsearchDocumentStore()\n"
+        'document_store.name = "DocumentStore"\n'
         "retri = BM25Retriever(document_store=document_store)\n"
         "retri_2 = TfidfRetriever(document_store=document_store)\n"
         "\n"
@@ -497,6 +498,7 @@ def test_generate_code_imports_no_pipeline_cls():
         "from haystack.nodes import BM25Retriever\n"
         "\n"
         "document_store = ElasticsearchDocumentStore()\n"
+        'document_store.name = "DocumentStore"\n'
         "retri = BM25Retriever(document_store=document_store)\n"
         "\n"
         "p = Pipeline()\n"
@@ -524,6 +526,7 @@ def test_generate_code_comment():
         "from haystack.pipelines import Pipeline\n"
         "\n"
         "document_store = ElasticsearchDocumentStore()\n"
+        'document_store.name = "DocumentStore"\n'
         "retri = BM25Retriever(document_store=document_store)\n"
         "\n"
         "p = Pipeline()\n"
@@ -717,6 +720,7 @@ def test_load_from_deepset_cloud_query():
     assert isinstance(retriever, BM25Retriever)
     assert isinstance(document_store, DeepsetCloudDocumentStore)
     assert document_store == query_pipeline.get_document_store()
+    assert document_store.name == "DocumentStore"
 
     prediction = query_pipeline.run(query="man on horse", params={})
 

test/pipelines/test_pipeline_yaml.py

@@ -491,6 +491,9 @@ def __init__(self, other_node: OtherNode):
         )
     pipeline = Pipeline.load_from_yaml(path=tmp_path / "tmp_config.yml")
     assert isinstance(pipeline.get_node("custom_node"), CustomNode)
+    assert isinstance(pipeline.get_node("custom_node").other_node, OtherNode)
+    assert pipeline.get_node("custom_node").name == "custom_node"
+    assert pipeline.get_node("custom_node").other_node.name == "other_node"
 
 
 def test_load_yaml_custom_component_with_helper_class_in_init(tmp_path):