HTML5 - JavaScript functions

 This article describes a feature or macro function that is experimental and may be subject to change.

A special class is available to JavaScript code running inside HTML5 pages. It allows access to a few values and functions.

The class itself is static and is called MapTool.

Functions

• MapTool.log() - Anything passed to this method will be sent to the chat window, just like a broadcast() to self. Additionally, console.log() will be redirected to the chat window.

• MapTool.getName() - Returns the name of the panel.

• MapTool.getKind() - Returns the kind of panel the JavaScript is inside of: frame5() or dialog5().

• MapTool.getUserData() - Returns a Promise representing the data passed to the panel via the value option.

[html.frame5("Example Dialog",
             "lib://myAddon/index.html",
             'value={"key": "some arbitrary data"}')]

The variable value is injected into the JavaScript as a global variable (ie. as a property of the window object), such that it can be accessed as either window.value or just value after the window's load event is triggered.

// MapTool creates an implied assignment to 'value' here, but
// it doesn't resolve until the document is finished loading...

// Technique #1
window.addEventListener("load", function() {
    MapTool.getUserData().then(
        v => console.log(`Method 1\n${MapTool.getKind()}, data: ${v}`)
    );
});

// Technique #2
let v = await MapTool.getUserData();
console.log(`Method 2\n${MapTool.getKind()}, data: ${v}`)

It is not defined which resolves first, the Promise from getUserData() or the window's load event. DO NOT rely on any particular order.