Adding graph docs

Author: apetenchea

arangoasync/graph.py

@@ -64,6 +64,15 @@ def name(self) -> str:
         """Name of the graph."""
         return self._name
 
+    @property
+    def db_name(self) -> str:
+        """Return the name of the current database.
+
+        Returns:
+            str: Database name.
+        """
+        return self._executor.db_name
+
     @property
     def serializer(self) -> Serializer[Json]:
         """Return the serializer."""
@@ -686,16 +695,16 @@ def response_handler(resp: Response) -> EdgeCollection[T, U, V]:
     async def delete_edge_definition(
         self,
         name: str,
-        purge: bool = False,
+        drop_collections: Optional[bool] = None,
         wait_for_sync: Optional[bool] = None,
     ) -> None:
         """Delete an edge definition from the graph.
 
         Args:
             name (str): Edge collection name.
-            purge (bool): If set to `True`, the edge definition is not just removed
-                from the graph but the edge collection is also deleted completely
-                from the database.
+            drop_collections (bool | None): If set to `True`, the edge definition is not
+                just removed from the graph but the edge collection is also deleted
+                completely from the database.
             wait_for_sync (bool | None): If set to `True`, the operation waits for
                 changes to be synced to disk before returning.
 
@@ -705,7 +714,9 @@ async def delete_edge_definition(
         References:
             - `remove-an-edge-definition <https://docs.arangodb.com/stable/develop/http-api/graphs/named-graphs/#remove-an-edge-definition>`__
         """  # noqa: E501
-        params: Params = {"dropCollections": purge}
+        params: Params = {}
+        if drop_collections is not None:
+            params["dropCollections"] = drop_collections
         if wait_for_sync is not None:
             params["waitForSync"] = wait_for_sync
 

docs/collection.rst

@@ -6,8 +6,10 @@ by its name which must consist only of hyphen, underscore and alphanumeric
 characters. There are three types of collections in python-arango:
 
 * **Standard Collection:** contains regular documents.
-* **Vertex Collection:** contains vertex documents for graphs (not supported yet).
-* **Edge Collection:** contains edge documents for graphs (not supported yet).
+* **Vertex Collection:** contains vertex documents for graphs. See
+  :ref:`here <vertex-collections>` for more details.
+* **Edge Collection:** contains edge documents for graphs. See
+  :ref:`here <edge-collections>` for more details.
 
 
 Here is an example showing how you can manage standard collections:

docs/document.rst

@@ -42,6 +42,26 @@ collection:
         "friends": ["robin", "gordon"]
     }
 
+.. _edge-documents:
+
+**Edge documents (edges)** are similar to standard documents but with two
+additional required fields ``_from`` and ``_to``. Values of these fields must
+be the handles of "from" and "to" vertex documents linked by the edge document
+in question (see :doc:`graph` for details). Edge documents are contained in
+:ref:`edge collections <edge-collections>`. Here is an example of a valid edge
+document in "friends" edge collection:
+
+.. code-block:: python
+
+    {
+        "_id": "friends/001",
+        "_key": "001",
+        "_rev": "_Wm3d4le--_",
+        "_fro"': "students/john",
+        "_to": "students/jane",
+        "closeness": 9.5
+    }
+
 Standard documents are managed via collection API wrapper:
 
 .. code-block:: python