===========
HTTP Client
===========

To connect to a server over HTTP, you need to create a client object and call the
``connect`` method.

The connect method accepts the following parameters:

* **endpointUrl** - The URL of the server.

    Servers support two kinds of schemes for HTTP endpoints.

      * **opc.http://host:port/path**
      * **opc.https://host:port/path**

    Some servers may also support HTTP/HTTPS schemes:

      * **http://host:port/path**
      * **https://host:port/path**


* **transportProfile** - The transport profile to use can be one of the following:

    * **ua.TranportProfileUri.HttpsJson** expands to string *http://opcfoundation.org/UA-Profile/Transport/https-json*
    * **ua.TranportProfileUri.HttpsBinary** expands to string *http://opcfoundation.org/UA-Profile/Transport/https-uabinary*

    This parameter is optional. If not provided, the client will try to connect using binary encoding.

HTTP Examples
-------------

Binary Encoding
~~~~~~~~~~~~~~~

The following example shows how to connect to a server using binary encoding over HTTP.

.. literalinclude:: ../examples/client/client_connect_http_binary.lua
    :language: lua
    :lines: 16-22

`Full source <../_static/client/client_connect_http_binary.lua>`__

You can also omit the second parameter; the client will try to connect using binary encoding.

.. literalinclude:: ../examples/client/client_connect_https_binary_default.lua
    :language: lua
    :lines: 16-22


To connect to a server over HTTPS, you need to pass URL with `opc.https://` scheme.

.. literalinclude:: ../examples/client/client_connect_https_binary.lua
    :language: lua
    :lines: 16-22

`Full source <../_static/client/client_connect_https_binary.lua>`__


JSON Encoding
~~~~~~~~~~~~~

JSON encoding is a non-standard way to communicate between OPCUA clients and servers.
Because of this, you can only connect to RealTimeLogic server using JSON encoding.

The following example shows how to connect to a server using JSON encoding over HTTP.

.. literalinclude:: ../examples/client/client_connect_https_json.lua
    :language: lua
    :lines: 16-22

`Full source <../_static/client/client_connect_https_json.lua>`__