Developing Workstation-Enabled Applications

Introduction

To start using Mendix Workstation, implement your own custom logic for interacting with devices. The following nanoflows and actions serve as the core building blocks for integrating devices into your Mendix applications and tailoring the functionality to your specific requirements.

Prerequisites

To help you develop your application, familiarize yourself with the Mendix Studio Pro Guide, especially the following topics:

• Studio Pro Overview
• Data in the Domain Model
• Pages
• Microflows and Nanoflows
• Development Best Practices

Understanding the Domain Model

The Workstation domain model contains the following entities:

• Station - A non-persistent entity representing the Workstation Client configuration.
• Device - A non-persistent entity representing a connectable peripheral device. Includes the name, class and state (Available, Connected, or Error). Specialize this to maintain your device specific state.
• AppKeyPair - A persistent entity to store the app's key pair. The public key needs to be entered in the corresponding app in the Workstation Management.

Using the Nanoflows and Actions

The following section provides more information about using the Workstation nanoflows and Java actions in your Mendix application.

SendDeviceRequest

Call SendDeviceRequest to send a message to a device and return the response or error. Requires Workstation Client 4.0 or later, and a device that supports requests. For more information about the supported message syntax, see Configuring Devices. This action has the following parameters:

• device
• message

SendDeviceMessage

Call SendDeviceMessage to send a message to a device. For more information about the supported message syntax, see Configuring Devices. This action has the following parameters:

• device
• message

Responses are passed through message callbacks. For more information, see GetCreateDevice (onMessage), WaitForDeviceMessage, and SubscribeToDeviceMessages.

WaitForDeviceMessage

Call WaitForDeviceMessage to wait for a message from the connected device for the duration of the specified timeout period. This action has the following parameters:

• device
• timeout

WaitForObjectChange

Call WaitForObjectChange to wait for changes in the attributes of the specified object for the duration of the specified timeout period. This action has the following parameters:

• objectToObserve
• attributes
• timeout

GetCreateDevice

Call this nanoflow to create and configure a device, and define the actions that should happen on connection, disconnection, or messages from the device. This action has the following parameters:

• name
• class
• initialize
• createDevice
• entity
• onConnect
• onMessage
• onDisconnect

ConnectDevice

Call this action to connect to a specific device.

DisconnectDevice

Call this action to disconnect from a specific device.

Initialize

This action sets up communication with the Workstation Client. It should be automatically called through the initialize parameter of GetStation or GetCreateDevice.

GetStation

Call GetStation to retrieve the current Workstation Client configuration and devices. This action creates and returns a station object with a linked device object per peripheral.

To interact with a specific device, it is better to use GetCreateDevice instead. GetCreateDevice has a more convenient API, allows specialization, and does not create station and device objects which may not be needed.

SubscribeToObjectChanges

Call SubscribeToObjectChanges to trigger a nanoflow when the specified object changes. This action has the following parameters:

• objectToObserve
• attributes
• callback
• applicationContext

SubscribeToDeviceMessages

Call SubscribeToDeviceMessages to trigger a nanoflow when a message is received from a device. This action has the following parameters:

• device
• callback
• applicationContext

SubscribeToDeviceErrors

Call SubscribeToDeviceErrors to trigger a nanoflow on device connection error. This action has the following parameters:

• device
• callback
• applicationContext

Unsubscribe

Call Unsubscribe to end a subscription.

Private Nanoflows

CreateStation, CommitStation, CreateDevice, and CommitDevice are private nanoflows, required be compatible with strict mode.

Widgets

The following widgets allow you to specify when to execute an action:

• On Load/Unload - Execute the action when the widget is first rendered, or when it is removed (unloaded).
• On Change - Execute the action when the specified attribute changes.
• On Equal - Execute the action when an attribute is equal to the specified expression.
• On True - Execute the action when the specified expression is true.

Error Logs

Logs for the Workstation Management, Client, and Connector are available in case of issues. For more information about accessing the logs, see Troubleshooting Mendix Workstation.

Deploying Your Application

There are multiple ways to deploy a Mendix application. You can deploy to your local machine for development and testing. You can deploy to Mendix Cloud, which is the default location for both free and licensed apps. You can also deploy to SAP Business Technology (SAP BTP) Platform, Kubernetes and Cloud Foundry-based platforms, Docker containers, Azure, or to a server you configured yourself. For more information, see Deploying Apps.