.. testsetup::

    from arango import create

    c = create()
    c.test.create()

    # create FROM document
    from_doc = c.test.documents.create({
        "sample_key": "sample_value"
    })

    # create TO document
    to_doc = c.test.documents.create({
        "sample_key1": "sample_value1"
    })

.. _edges:

Edges
-----

An edge is an entity that represents a connection between two
documents. The main idea of edges is that you can build your own
graph (tree) between sets of documents and then perform searches within
the document hierarchy.

In order to define a vertex, a connection between a ``from_document`` and ``to_document`` 
should be specified during the creation of the edge:


.. testcode::

    from arango import create

    c = create()
    c.test.create()

    # create FROM document
    from_doc = c.test.documents.create({
        "sample_key": "sample_value"
    })

    # create TO document
    to_doc = c.test.documents.create({
        "sample_key1": "sample_value1"
    })

    # creating edge with custom data - (a vertex) 
    c.test.edges.create(from_doc, to_doc, {"custom": 1})

.. warning::
    Code below should be implemented by using ``AQL`` (:doc:`queries`).
    Not implemented at the moment.


.. testcode::

    # getting edge by document
    # c.test.edges(from_doc)

    # getting with direction
    # c.test.edges(from_doc, direction="in")

    # assert c.test.edges(from_doc).first.from_document == from_doc
    # assert c.test.edges(from_doc).first.to_document == to_doc


.. _edges proxy:

Edges for Collection instance
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Edges are accessible via a collection instance, for example ``connection.collection.sample_collection.edges``.
Usually this expressions looks lot shorter.

Basically via `edges` shortcut accessible **Edges Proxy** - Proxy object which have several shortcuts and produce ``Resultset`` object.

Below described basic method within ``Edges`` proxy:

.. autoclass:: arango.edge.Edges
    :members: create, delete, update


Making queries
~~~~~~~~~~~~~~

.. warning::
    This functionality not implmented yet. Use **AQL** -
    :doc:`queries` section with custom wrapper to work with Edges.

More details in :term:`Edges REST Api` documentation of **ArangoDB**


.. _edge:

Edge
~~~~

Edge instance methods consist from basic **CRUD** methods and additional
methods specific obly for **Edges**:

.. autoclass:: arango.edge.Edge
    :members: id, rev, create, update, delete, save, body,
              from_document, to_document, get