[AUR-395] Adopt Example1 disclaimer pipeline (#42)

* Adopt Example1 disclaimer pipeline
* Update Document class
* Add composite components
* Modify Extractor behaviours

knowledgehub/documents/base.py

@@ -1,12 +1,43 @@
+from typing import Any, Optional
+
 from haystack.schema import Document as HaystackDocument
 from llama_index.bridge.pydantic import Field
 from llama_index.schema import Document as BaseDocument
+from pyparsing import TypeVar
 
+IO_Type = TypeVar("IO_Type", "Document", str)
 SAMPLE_TEXT = "A sample Document from kotaemon"
 
 
 class Document(BaseDocument):
-    """Base document class, mostly inherited from Document class from llama-index"""
+    """
+    Base document class, mostly inherited from Document class from llama-index.
+
+    This class accept one positional argument `content` of an arbitrary type, which will
+        store the raw content of the document. If specified, the class will use
+        `content` to initialize the base llama_index class.
+    """
+
+    content: Any
+
+    def __init__(self, content: Optional[Any] = None, *args, **kwargs):
+        if content is None:
+            if kwargs.get("text", None) is not None:
+                kwargs["content"] = kwargs["text"]
+            elif kwargs.get("embedding", None) is not None:
+                kwargs["content"] = kwargs["embedding"]
+        elif isinstance(content, Document):
+            kwargs = content.dict()
+        else:
+            kwargs["content"] = content
+            if content:
+                kwargs["text"] = str(content)
+            else:
+                kwargs["text"] = ""
+        super().__init__(*args, **kwargs)
+
+    def __bool__(self):
+        return bool(self.content)
 
     @classmethod
     def example(cls) -> "Document":
@@ -23,7 +54,7 @@ class Document(BaseDocument):
         return HaystackDocument(content=text, meta=metadata)
 
     def __str__(self):
-        return self.text
+        return str(self.content)
 
 
 class RetrievedDocument(Document):