On start-up, the client lists available scenarii. When the user selects a scenario, the current scenario and step are stored on the hardware configuration's entry in OpenERP.

When the client sends a message to the server, the next step is selected depending on the current step and the message sent. Then, the server returns the result of the step, which contains the step type code and the text to display on the hardware screen. Unlike the standard OpenERP Workflow, each step needs to find a valid transition, because a step needs to be displayed on the hardware screen at all times.

If you plan to use the specific "sentinel.py", you will need the "openobject-library" Python module.

To test the module, some demo scenarii are available in the demo directory of the module.

You have to declare some hardware scanners in OpenERP.

Go to "Warehouse > Configuration > Scanner Hardware" and create a new record.

The "step type code" sent by the "sentinel.py" client at start-up is the IP address of the hardware, if connected through SSH.

The sentinel.py client uses a config file named .oerpsentinelrc, using the standard ini format.

This file simply contains information for server connection (hostname, port, username, password and database).

The preferred way to start the creation of a scenario is to create steps and transitions in diagram view.

Once your steps are created, you can write python code directly from OpenERP, or you can export the scenario to write the python code with your preferred code editor.

In the python code of each step, some variables are available :

• cr : Cursor to the database
• uid : ID of the user executing the step (user used to log in with the sentinel, or user configured on the hardware, if any)
• pool : Pooler to the database
• model : Pooler on the model configured on the scenario
• context : Context used on the step
• m or message : Last message sent by the hardware
• t or terminal : Browse record on the hardware executing the step
• tracer : Value of the tracer of the used transition to access this step
• wkf or workflow : Workflow service
• scenario : Browse record on the current scenario for the hardware

Some of these variables are also available on transition conditions execution.

As stated previously, the step must always return : - A step type code, in the act variable - A message to display on the hardware screen, in the res variable - Optionally, a default value, in the val variable

The import and export scripts are in the script directory of the module

A scenario is exported as a set of files, containing :

• scenario.xml : Global description of the scenario (name, warehouses, steps, transitions, etc.)
• A .py file per step : The name of the file is the uuid of the step