Secure context
This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
The read-only length
property returns an integer value indicating the number of items in the input source list represented by the XRInputSourceArray
object.
Syntax
let inputSourceCount = xrInputSourceArray.length;
Value
An integer value indicating the number of XRInputSource
objects representing WebXR input sources are includled in the array.
Examples
In this example, a game that requires at least one input source uses length
to check this before proceeding to allow the user to play the game.
let sources = xrSession.inputSources; if (sources.length === 0) { showAlertDialog("You need to have at least one controller to play Super Duper Shark Jump Fest 9000.", [ { label: "Shop Now", url: "https://www.amazon.com/s?k=vr+controllers" }, { label: "Quit" handler: quitGame } ]); }
Here, if length
is 0, a hypothetical showAlertDialog()
function is called with a prompt string explaining the need for a controller, and an array of objects, each describing a button and what should happen when it's clicked. The first takes the user to an Amazon.com search for VR controllers, and the second calls a quitGame()
function to start shutting the game program down.
Specifications
Specification | Status | Comment |
---|---|---|
WebXR Device API The definition of 'XRInputSourceArray.length' in that specification. |
Working Draft | Initial definition. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
length | Chrome Full support 79 | Edge Full support 79 | Firefox No support No | IE No support No | Opera No support No | Safari No support No | WebView Android No support No | Chrome Android Full support 79 | Firefox Android No support No | Opera Android No support No | Safari iOS No support No | Samsung Internet Android Full support 11.2 |
Legend
- Full support
- Full support
- No support
- No support