mapbox-gl/js/util/browser/ajax.js

A WebGL interactive maps library

'use strict';

exports.getJSON = function(url, callback) {
    var xhr = new XMLHttpRequest();
    xhr.open('GET', url, true);
    xhr.onerror = function(e) {
        callback(e);
    };
    xhr.onload = function() {
        if (xhr.status >= 200 && xhr.status < 300 && xhr.response) {
            var data;
            try {
                data = JSON.parse(xhr.response);
            } catch (err) {
                return callback(err);
            }
            callback(null, data);
        } else {
            callback(new Error(xhr.statusText));
        }
    };
    xhr.send();
    return xhr;
};

exports.getArrayBuffer = function(url, callback) {
    var xhr = new XMLHttpRequest();
    xhr.open('GET', url, true);
    xhr.responseType = 'arraybuffer';
    xhr.onerror = function(e) {
        callback(e);
    };
    xhr.onload = function() {
        if (xhr.status >= 200 && xhr.status < 300 && xhr.response) {
            callback(null, xhr.response);
        } else {
            callback(new Error(xhr.statusText));
        }
    };
    xhr.send();
    return xhr;
};

function sameOrigin(url) {
    var a = document.createElement('a');
    a.href = url;
    return a.protocol === document.location.protocol && a.host === document.location.host;
}

exports.getImage = function(url, callback) {
    var img = new Image();
    if (!sameOrigin(url)) {
        img.crossOrigin = 'Anonymous';
    }
    img.onload = function() {
        callback(null, img);
    };
    img.src = url;
    img.getData = function() {
        var canvas = document.createElement('canvas');
        var context = canvas.getContext('2d');
        canvas.width = img.width;
        canvas.height = img.height;
        context.drawImage(img, 0, 0);
        return context.getImageData(0, 0, img.width, img.height).data;
    };
    return img;
};

exports.getVideo = function(urls, callback) {
    var video = document.createElement('video');
    video.onloadstart = function() {
        callback(null, video);
    };
    for (var i = 0; i < urls.length; i++) {
        var s = document.createElement('source');
        if (!sameOrigin(urls[i])) {
            video.crossOrigin = 'Anonymous';
        }
        s.src = urls[i];
        video.appendChild(s);
    }
    video.getData = function() { return video; };
    return video;
};