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Docs: ApiGear Core

Examples

This section contains examples for scripted clients that connect to remote services.

Counter Client​

A simple client that connects to a remote counter service and calls the increment method:

// counter_client.js
const channel = $createChannel();
const client = channel.createClient("counter");

// Monitor property changes from the remote service
client.onProperty("count", function (value) {
  console.log("client: count changed to", value);
});

function main() {
  console.log("Counter client started");

  // Call the remote increment method multiple times
  for (let i = 0; i < 5; i++) {
    console.log(`Calling increment (${i + 1}/5)`);
    client.callMethod("increment");
  }

  console.log("All increment calls sent");
}

Run the client (requires a running counter service):

apigear sim run counter_client.js --no-serve

Vehicle Client​

A more complex example connecting to multiple remote services:

// vehicle_client.js
const channel = $createChannel();
const commands = channel.createClient("vehicle.Commands");
const state = channel.createClient("vehicle.State");
const indicators = channel.createClient("vehicle.Indicators");

// Monitor state changes
state.onProperty("speed", function(speed) {
    console.log(`Client - Speed: ${speed} km/h`);
});

state.onProperty("fuelLevelWarning", function(warning) {
    if (warning) {
        console.log("Client - Low fuel warning!");
    }
});

indicators.onProperty("checkEngine", function(value) {
    console.log(`Client - Check engine: ${value}`);
});

function main() {
    console.log("Vehicle client starting...");

    // Turn on vehicle systems
    commands.callMethod("turnOn");

    // Wait a bit then turn off
    setTimeout(function() {
        console.log("Turning off vehicle systems...");
        commands.callMethod("turnOff");
    }, 3000);
}

Client API Reference​

Creating a Channel​

const channel = $createChannel();  // Uses default ws://localhost:4333/ws
const channel = $createChannel("ws://custom-host:5555/ws");

Creating a Client​

const client = channel.createClient("service.name");

Calling Methods​

client.callMethod("methodName");
client.callMethod("methodName", arg1, arg2);

Monitoring Properties​

client.onProperty("propertyName", function(value) {
    console.log("Property changed:", value);
});

Listening for Signals​

client.onSignal("signalName", function(args) {
    console.log("Signal received:", args);
});