get()

Returns an object containing current values of all properties.

console.log("dotAtlas properties", dotatlas.get());

const elevations = dotatlas.get("layers")[0];
console.log("elevation layer properties", elevations.get());

get(prop)

Returns the current value of one prop. If the provided string does not correspond to any property name, the result is undefined.

console.log(dotatlas.get("layers"));

const elevations = dotatlas.get("layers")[0];
console.log("light intensity", elevations.get("lightIntensity"));

get(prop, args...)

Returns the current value of the requested read-only prop, optionally parameterized by the provided args. The number and type of arguments depends on the requested read-only property, see the documentation of the specific the property for details.

The following example retrieves the current visualization image in the JPEG format.

const bitmap = dotatlas.get("imageData", {
  format: "image/jpg", quality: 0.8
});

The following example gets the elevation value at the provided screen coordinates:

const elevations = dotatlas.get("layers")[0];
const elevationValue = elevations.get("elevationAt", 150, 200);

set(prop, value)

Sets a new value for one property of dotAtlas or layer instance. If the string passed in the prop parameter does not correspond to any property, the call will be ignored.

dotatlas.set("layers", [ /* layers to set */ ]);

const elevations = dotatlas.get("layers")[0];
elevations.set("lightAzimuth", 2 * Math.PI);

set(props)

Sets values of dotAtlas global properties provided in the literal object props.

dotatlas.set({
  "maxZoomLevel": 32768,
  "layers": [
    // layers to set
  ]
});

const elevations = dotatlas.get("layers")[0];
elevations.set({
  "lightIntensity": 0.5,
  "lightAzimuth": 2 * Math.PI
});

on()

Registers a listener for a dotAtlas or layer event.

dotatlas.on(event, listener);

The event parameter is the event name. The listener parameter is the function to call when the event occurs. For most events, the function will receive the event details object as the first and only parameter.

Note that event names here are slightly different from the event names used in the set() method. To get the event name to use with the on(), once(),off() method, take the event property name, remove the leading "on" and lower-case the first letter, for example:

As opposed to using the set() method, this method preserves the previously registered listeners. Typical invocations of this method will be similar to:

dotatlas.on("redraw", e => { /* react to visualization redraw */ });

const elevations = dotatlas.get("layers")[0];
elevations.on("maxElevationChanged", e => { /* react to peak change */ });

For an overview of dotAtlas event handling, see the Listening to events guide.

once()

Registers a one-time listener for a dotAtlas or layer event. Once the event is triggered, the listener will be removed from the listeners list and will not be notified of further events.

dotatlas.once(event, listener);

The event parameter is the event name. Note the event naming convention differences when using on(), once() and off() methods. The listener parameter is the function to call when the event occurs.

The typical invocations of this method will look like this:

dotatlas.once("redraw", e => { /* react to visualization redraw */ });

const elevations = dotatlas.get("layers")[0];
elevations.once("maxElevationChanged", e => { /* react to peak change */ });

If the listener parameter is not provided, this method returns a Promise that is resolved once the event is triggered:

dotatlas.once("layersChanged").then(e => {
  // handle the one-time event
});

For an overview of dotAtlas event handling, see the Listening to events guide.

off()

Removes a listener from the list of listeners registered for the specified event.

dotatlas.off(event, listener);

The event parameter is the event name. Note the event naming convention differences when using on(), once() and off() methods. The listener parameter is the function to remove from the listener list.

As opposed to using the set() method, this method will preserve the other listeners registered for the event.

The invocations of this method will typically be similar to:

const redrawListener = e => { console.log("visualization redrawn", e ); };
dotatlas.on("redraw", redrawListener);
dotatlas.off("redraw", redrawListener);