Metadata-Version: 2.1
Name: cdp-client
Version: 1.0.2
Summary: Provides an API for CDP applications to fetch application structure and cdp object values
Home-page: https://github.com/CDPTechnologies/PythonCDPClient
Author: CDP Technologies AS
Author-email: info@cdptech.com
License: MIT
Keywords: cdp cdpstudio client cdp-client cdp_client
Platform: UNKNOWN
Classifier: Development Status :: 5 - Production/Stable
Classifier: Environment :: Console
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: OS Independent
Classifier: Topic :: Software Development
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.3
Classifier: Programming Language :: Python :: 3.4
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Requires-Dist: promise (>=2.1)
Requires-Dist: websocket-client (>=0.47.0)
Requires-Dist: protobuf (>=3.5.2)
Requires-Dist: mock (>=2.0.0)

CDP-Client
==========

A simple python interface to communicate with CDP applications to retrieve application structure and object values. The API makes heavy use of promise library for asynchronous operations. For more information see https://pypi.python.org/pypi/promise


Installation
------------

::

    $ pip install cdp-client

Usage
-----

The example below shows how you subscribe to CDP signal value changes.

.. code:: python

    from cdp_client import cdp

    def on_value_changed(value, timestamp):
        print(value)

    def subscribe_to_value_changes(node):
        node.subscribe_to_value_changes(on_value_changed)

    client = cdp.Client('127.0.0.1')
    client.find_node('AppName.ComponentName.SignalName').then(subscribe_to_value_changes)
    client.run_event_loop()

API
---

Before all examples, you need:

.. code:: python

    from cdp_client import cdp

Global API
~~~~~~~~~~

Client(host, port, auto_reconnect)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

- Arguments

    host - String for hosts ip address

    port - Optional port number to connect to. If not specified default port 7689 is used.

    auto_reconnect - Optional argument to enable/disable automatic reconnect when connection is lost. Defaults to True if not specified.

- Returns

    The connected client object.

- Usage

    .. code:: python

        client = cdp.Client('127.0.0.1')

Instance Methods / Client
~~~~~~~~~~~~~~~~~~~~~~~~~

client.root_node()
^^^^^^^^^^^^^^^^^^

Gets the application Node object of the connected application.

- Returns

    Promise containing root Node object when fulfilled.

- Usage

    .. code:: python

        client.root_node().then(on_success).catch(on_error)

client.find_node(path)
^^^^^^^^^^^^^^^^^^^^^^

Searches for the node specified by full dot separated path. **The requested node must reside in the application client was connected to. Root node is not considered part of the path.**

- Arguments

    path - Dot separated string to target node

- Returns

    Promise containing requested Node object when fulfilled. Otherwise NotFoundError when rejected.

- Usage

    .. code:: python

        client.find_node('AppName.ComponentName.SignalName').then(on_success).catch(on_error)

client.run_event_loop()
^^^^^^^^^^^^^^^^^^^^^^^

Runs the event loop that serves network communication layer for incoming/outgoing data. **This is a blocking call that must be run for any communication to happen.** The method can be cancelled by calling disconnect.

client.disconnect()
^^^^^^^^^^^^^^^^^^^

Stops the event loop and closes the connection to connected application. This method also releases the blocking run_event_loop call.

Instance Methods / Node
~~~~~~~~~~~~~~~~~~~~~~~

node.name()
^^^^^^^^^^^

- Returns

    The name of the Node object. Names in a parent node are all unique.

node.path()
^^^^^^^^^^^

- Returns

    A dot separated path of the Node object starting with application name.

node.parent()
^^^^^^^^^^^^^

- Returns

    The parent Node object.

node.type()
^^^^^^^^^^^

- Returns

    The type of the Node object returned as one of the cdp.NodeType values.

node.last_value()
^^^^^^^^^^^^^^^^^

- Returns

    The last known value received by the Node object.

node.set_value(value, timestamp)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Sets a new value for the Node object. Timestamp will be ignored in current implementation.

- Arguments

    value - New value

    timestamp - UTC time in nanoseconds since Epoch

node.is_read_only()
^^^^^^^^^^^^^^^^^^^

- Returns

    False if nodes value cannot be set, otherwise True.

node.is_leaf()
^^^^^^^^^^^^^^

- Returns

    True if node doesn't have any children, otherwise False.

node.child(name)
^^^^^^^^^^^^^^^^

- Arguments

    name - Child nodes name to search for

- Returns

    Promise containing requested Node object when fulfilled.

- Usage

    .. code:: python

        node.child('NodeName').then(on_success).catch(on_error)

node.children()
^^^^^^^^^^^^^^^

- Returns

    Promise containing all children of this Node object when fulfilled.

- Usage

    .. code:: python

        node.children().then(on_success).catch(on_error)

node.for_each_child(callback)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Loops through all children and calls callback function for each of them

- Arguments

    callback - Function(node)

- Returns

    Promise containing all children of this Node object when fulfilled.

- Usage

    .. code:: python

        def on_callback(child):
            do something

        node.for_each_child(on_callback)

node.subscribe_to_structure_changes(callback)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Starts listening structure changes and passes the changes to provided callback funtion

- Arguments

    callback - Function(added_nodes, removed_nodes) where added_nodes and removed_nodes is a list

- Usage

    .. code:: python

        def on_change(added_nodes, removed_nodes):
            do something

        node.subscribe_to_structure_changes(on_change)

node.subscribe_to_value_changes(callback)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Starts listening value changes and passes the changes to provided callback function

- Arguments

    callback - Function(value, timestamp)

- Usage

    .. code:: python

        def on_change(value, timestamp):
            do something

        node.subscribe_to_value_changes(on_change)


node.unsubscribe_from_structure_changes(callback)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Stops listening previously subscribed structure changes

- Arguments

    callback - Function(added_nodes, removed_nodes) where added_nodes and removed_nodes is a list

- Usage

    .. code:: python

        def on_change(added_nodes, removed_nodes):
            do something

        node.unsubscribe_from_structure_changes(on_change)

node.unsubscribe_from_value_changes(callback)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Stops listening previously subscribed value changes

- Arguments

    callback - Function(value, timestamp)

- Usage

    .. code:: python

        def on_change(value, timestamp):
            do something

        node.unsubscribe_from_value_changes(on_change)

Tests
-----

To run the test suite execute the following command in package root folder:

.. code:: sh

    $ python setup.py test

License
-------

`MIT
License <https://github.com/CDPTechnologies/PythonCDPClient/blob/master/LICENSE.txt>`__


