Examples on query and mutation
==============================
Fetch information of devices
----------------------------

.. code:: python

    query{
        devices{ 
            name                # e.g. get the names of all devices
        }
    }  

    query{
        devices(pattern: "*tg_test*"){            #filter result with pattern
            name
        }
    }

Accessing attributes
--------------------

.. code:: python 

    query{
        devices(pattern: "sys/tg_test/1"){
            name,
            attributes {
                name,
                datatype,
                }
            }
        }

    query{
        devices(pattern: "sys/tg_test/1"){
            name,
            attributes(pattern: "*scalar*") {
                    name,
                    datatype,
                    dataformat,
                    label,
                    unit,
                    description,
                    value,
                    quality,
                    timestamp
                }
                server{
                id,
                host
            }
        }
    }

Deleting device property
------------------------

.. code:: python 

    mutation{
        deleteDeviceProperty(device:"sys/tg_test/1", name: "Hej"){
            ok,
            message
        }
    }

Putting device property 
-----------------------

.. code:: python 

    mutation{
        putDeviceProperty(device:"sys/tg_test/1", name: "Hej", value: "test"){
            ok,
            message
        }
    }

Deleting device property
------------------------

.. code:: python 

    mutation{
        deleteDeviceProperty(device:"sys/tg_test/1",name:"Hej"){
            ok,
            message
        }
    } 

Setting value for an attribute
------------------------------ 

.. code:: python 

    mutation{
        SetAttributeValue(device:"sys/tg_test/1", name: "double_scalar",value: 2){
            ok,
            message
        }
    }

Query all tango classes
-----------------------

.. code:: python 

    query{
        classes(pattern:"*"){
            name
        }
    }

Query all tango classes and corresponding devices
------------------------------------------------- 

.. code:: python 

    query{
        classes(pattern:"*"){
            name
            devices {
            name
            }
        }
    }