docs: add deprecation notes to docstrings (#4708)

haystack/document_stores/base.py

@@ -35,6 +35,8 @@ except (ImportError, ModuleNotFoundError):
 class BaseKnowledgeGraph(BaseComponent):
     """
     Base class for implementing Knowledge Graphs.
+
+    The BaseKnowledgeGraph component is deprecated and will be removed in future versions.
     """
 
     def __init__(self):

haystack/document_stores/graphdb.py

@@ -31,6 +31,8 @@ class GraphDBKnowledgeGraph(BaseKnowledgeGraph):
         prefixes: str = "",
     ):
         """
+        The GraphDBKnowledgeGraph component is deprecated and will be removed in future versions.
+
         Init the knowledge graph by defining the settings to connect with a GraphDB instance
 
         :param host: address of server where the GraphDB instance is running

haystack/document_stores/memory_knowledgegraph.py

@@ -19,6 +19,8 @@ class InMemoryKnowledgeGraph(BaseKnowledgeGraph):
 
     def __init__(self, index: str = "document"):
         """
+        The InMemoryKnowledgeGraph component is deprecated and will be removed in future versions.
+
         Init the in memory knowledge graph
 
         :param index: name of the index

haystack/nodes/retriever/text2sparql.py

@@ -27,6 +27,8 @@ class Text2SparqlRetriever(BaseGraphRetriever):
         use_auth_token: Optional[Union[str, bool]] = None,
     ):
         """
+        The Text2SparqlRetriever component is deprecated and will be removed in future versions.
+
         Init the Retriever by providing a knowledge graph and a pre-trained BART model
 
         :param knowledge_graph: An instance of BaseKnowledgeGraph on which to execute SPARQL queries.