Getting Started with Tasker and JavaScript

The following provides an introduction to coding with Tasker using JavaScript. Tasker is a powerful automation app for Android that allows users to perform actions based on triggers and conditions. By incorporating JavaScript, you can extend Tasker's capabilities even further. This guide will walk through creating simple scripts to automate tasks on your device.

What is Tasker?

Tasker is an Android application that enables users to automate various actions on their device. It works by creating "Profiles" that contain "Tasks," which are sets of actions executed when certain conditions are met.

Why Use JavaScript with Tasker?

While Tasker provides a wide range of built-in actions, using JavaScript allows for performing complex calculations, manipulating data, and interacting with web content in ways that aren't possible with Tasker's native actions alone.

Setting Up Tasker for JavaScript

1. Install Tasker: Download and install Tasker from the Google Play Store.
2. Enable JavaScript Support: Tasker has built-in support for JavaScript through the "JavaScript" action.

Creating Your First JavaScript Task

Create a simple Tasker task that uses JavaScript to display a greeting message based on the time of day.

Step 1: Create a New Task

1. Open Tasker and navigate to the "Tasks" tab.
2. Tap the + button to create a new task.
3. Name the task GreetUser and tap the checkmark.

Step 2: Add a JavaScript Action

1. In the task editing screen, tap the + button to add a new action.
2. Select Code > JavaScript.
3. In the "JavaScript" action, a text editor will appear where you can write your script.

Step 3: Write the JavaScript Code

Enter the following code into the editor:

// Get the current hour
var date = new Date();
var hour = date.getHours();

// Determine the greeting message
var greeting;
if (hour < 12) {
    greeting = "Good morning!";
} else if (hour < 18) {
    greeting = "Good afternoon!";
} else {
    greeting = "Good evening!";
}

// Store the greeting in a Tasker variable
setGlobal("greetingMessage", greeting);

This code performs the following actions:

• Retrieves the current hour of the day.
• Determines an appropriate greeting based on the time.
• Stores the greeting in a global Tasker variable called %greetingMessage.

Step 4: Display the Greeting

1. Tap the back button to save the JavaScript action.
2. Add a new action by tapping the + button.
3. Select Alert > Flash.
4. In the "Text" field, enter %greetingMessage.
5. Tap the back button to save the action.

This action will display the greeting message as a brief on-screen notification.

Step 5: Test the Task

1. Tap the play button at the bottom left to run the task.
2. A flash message should appear displaying "Good morning!", "Good afternoon!", or "Good evening!" depending on the current time.

Understanding Tasker Variables

Variables in Tasker are used to store and pass data between actions. They are denoted by the % symbol. There are two types:

• Local Variables: Begin with a lowercase letter and are available only within the current task (e.g., %myVar).
• Global Variables: Begin with an uppercase letter and are available across all tasks (e.g., %MyVar).

In the script above, setGlobal("greetingMessage", greeting); creates a global variable %greetingMessage accessible in subsequent actions.

Using JavaScript to Manipulate Tasker Variables

Access Tasker variables within JavaScript code using the global() and local() functions.

Example: Incrementing a Counter

Create a task that increments a counter each time it's run.

Step 1: Create a New Task

1. Go to the "Tasks" tab and create a new task named IncrementCounter.

Step 2: Add a JavaScript Action

1. Add a new action: Code > JavaScript.
2. Enter the following code:

// Get the current value of the counter
var counter = global("Counter");

// If the counter is undefined, initialize it
if (counter === undefined) {
    counter = 0;
}

// Increment the counter
counter++;

// Update the global variable
setGlobal("Counter", counter);

// Display the counter value
setGlobal("counterMessage", "Counter value: " + counter);

Step 3: Display the Counter Value

1. Add a new action: Alert > Flash.
2. Set the "Text" field to %counterMessage.

Step 4: Test the Task

1. Run the task multiple times to observe the counter incrementing.

Interacting with Web Content

JavaScript in Tasker can fetch and process data from the web using HTTP requests.

Example: Fetching a Joke from an API

Step 1: Create a New Task

1. Create a new task named GetJoke.

Step 2: Add a JavaScript Action

1. Add a new action: Code > JavaScript.
2. Enter the following code:

// Function to make HTTP GET request
function httpGet(url) {
    var xhr = new XMLHttpRequest();
    xhr.open("GET", url, false); // synchronous request
    xhr.send(null);
    return xhr.responseText;
}

// Fetch a random joke from the API
var response = httpGet("https://official-joke-api.appspot.com/random_joke");

// Parse the JSON response
var jokeData = JSON.parse(response);

// Construct the joke
var joke = jokeData.setup + "\n" + jokeData.punchline;

// Store the joke in a global variable
setGlobal("jokeText", joke);

Step 3: Display the Joke

1. Add a new action: Alert > Alert Dialog.
2. Set the "Title" field to Here's a Joke.
3. Set the "Text" field to %jokeText.

Step 4: Test the Task

1. Run the task to display a random joke.