A reliable DeviceOrientation and DeviceMotion Events API feature detection library

SensorCheck.js

/**
 * DeviceOrientation and DeviceMotion Events Detection API
 *
 * Example API Usage (Promise-based API):
 *
 *     supportsDeviceOrientationEvents().then(function() {
 *       console.log("Platform DeviceOrientation Events support OK");
 *     }, function(error) {
 *       console.error("Platform DeviceOrientation Events support KO");
 *     });
 *
 **/
(function() {

    var SENSOR_TYPE = [
        {
            name: "deviceorientation",
            testPaths: [["alpha"]],
            isSupported: undefined
        },
        {
            name: "devicemotion",
            testPaths: [["acceleration", "x"], ["accelerationIncludingGravity", "x"]],
            isSupported: undefined
        }
    ];

    function SensorCheck(sensor, successCallback, errorCallback) {

        // We only need to run each sensor check once per page load
        // so this is a neat performance optimization
        if (sensor.isSupported === true) {
            successCallback.call(this);
            return;
        } else if (sensor.isSupported === false) {
            errorCallback.call(this);
            return;
        }

        var e = {};
        var read = function(evt) { e = evt; };

        window.addEventListener(sensor.name, read, false);

        var c = 0;

        // Recursive IIFE sensor data checker
        (function runCheck() {
            setTimeout(function(){

                if (++c === 10) { // run test 10 times then time out
                    sensor.isSupported = false;
                    errorCallback.call(this);
                    window.removeEventListener(sensor.name, read, false);
                    return;
                }

                if (e === undefined || e === null) {
                    runCheck();
                    return;
                }

                try {
                    // Test that all of the event object property paths 
                    // are defined and not null
                    for (var i = 0, l = sensor.testPaths.length; i < l; i++) {

                        var testObj = e;

                        sensor.testPaths[i].forEach(function(val) {
                            testObj = testObj[val];
                            if (testObj === undefined || testObj === null) {
                                runCheck();
                                throw BreakException;
                            }
                        });

                    }      
                    
                    sensor.isSupported = true;
                    successCallback.call(this);
                    window.removeEventListener(sensor.name, read, false);

                } catch(e) {}

            }, 100);
        })();

    };

    // Add Sensor Test Promise APIs to DOM if they don't already exist

    if (!window.supportsDeviceOrientationEvents) {
        window.supportsDeviceOrientationEvents = function() {
            return new Promise(function(resolve, reject) {
                new SensorCheck(SENSOR_TYPE[0], resolve, reject);
            });
        };
    }

    if (!window.supportsDeviceMotionEvents) {
        window.supportsDeviceMotionEvents = function() {
            return new Promise(function(resolve, reject) {
                new SensorCheck(SENSOR_TYPE[1], resolve, reject);
            });
        };
    }

})();