Partial XHR polyfull for Node.js

CHANGES.md

@@ -22,6 +22,7 @@ Change Log
 * Fix flicker when adding, removing, or modifiying entities. [#3945](https://github.com/AnalyticalGraphicsInc/cesium/issues/3945)
 ##### Additions :tada:
 * Improved `MapboxImageryProvider` performance by 300% via `tiles.mapbox.com` subdomain switching. [#6426](https://github.com/AnalyticalGraphicsInc/cesium/issues/6426)
+* Added ability to invoke `sampleTerrain` from node.js to enable offline terrain sampling
 
 ### 1.44 - 2018-04-02
 

Source/Core/FeatureDetection.js

@@ -163,6 +163,14 @@ define([
         return isFirefox() && firefoxVersionResult;
     }
 
+    var isNodeJsResult;
+    function isNodeJs() {
+        if (!defined(isNodeJsResult)) {
+            isNodeJsResult = typeof process === 'object' && Object.prototype.toString.call(process) === '[object process]'; // eslint-disable-line
+        }
+        return isNodeJsResult;
+    }
+
     var hasPointerEvents;
     function supportsPointerEvents() {
         if (!defined(hasPointerEvents)) {
@@ -230,6 +238,7 @@ define([
         isFirefox : isFirefox,
         firefoxVersion : firefoxVersion,
         isWindows : isWindows,
+        isNodeJs: isNodeJs,
         hardwareConcurrency : defaultValue(theNavigator.hardwareConcurrency, 3),
         supportsPointerEvents : supportsPointerEvents,
         supportsImageRenderingPixelated: supportsImageRenderingPixelated,

Source/Core/Resource.js

@@ -10,6 +10,7 @@ define([
         './defineProperties',
         './deprecationWarning',
         './DeveloperError',
+        './FeatureDetection',
         './freezeObject',
         './getAbsoluteUri',
         './getBaseUri',
@@ -37,6 +38,7 @@ define([
         defineProperties,
         deprecationWarning,
         DeveloperError,
+        FeatureDetection,
         freezeObject,
         getAbsoluteUri,
         getBaseUri,
@@ -1772,13 +1774,75 @@ define([
         image.src = url;
     };
 
+    function decodeResponse(loadWithHttpResponse, responseType) {
+        switch (responseType) {
+          case 'text':
+              return loadWithHttpResponse.toString('utf8');
+          case 'json':
+              return JSON.parse(loadWithHttpResponse.toString('utf8'));
+          default:
+              return new Uint8Array(loadWithHttpResponse).buffer;
+        }
+    }
+
+    function loadWithHttpRequest(url, responseType, method, data, headers, deferred, overrideMimeType) {
+        // Note: only the 'json' and 'text' responseTypes transforms the loaded buffer
+        var URL = require('url').parse(url);
+        var http = URL.protocol === 'https:' ? require('https') : require('http');
+        var zlib = require('zlib');
+        var options = {
+            protocol : URL.protocol,
+            hostname : URL.hostname,
+            port : URL.port,
+            path : URL.path,
+            query : URL.query,
+            method : method,
+            headers : headers
+        };
+
+        http.request(options)
+            .on('response', function(res) {
+                if (res.statusCode < 200 || res.statusCode >= 300) {
+                    deferred.reject(new RequestErrorEvent(res.statusCode, res, res.headers));
+                    return;
+                }
+
+                var chunkArray = [];
+                res.on('data', function(chunk) {
+                    chunkArray.push(chunk);
+                });
+
+                res.on('end', function() {
+                    var result = Buffer.concat(chunkArray); // eslint-disable-line
+                    if (res.headers['content-encoding'] === 'gzip') {
+                        zlib.gunzip(result, function(error, resultUnzipped) {
+                            if (error) {
+                                deferred.reject(new RuntimeError('Error decompressing response.'));
+                            } else {
+                                deferred.resolve(decodeResponse(resultUnzipped, responseType));
+                            }
+                        });
+                    } else {
+                        deferred.resolve(decodeResponse(result, responseType));
+                    }
+                });
+            }).on('error', function(e) {
+                deferred.reject(new RequestErrorEvent());
+            }).end();
+    }
+
     Resource._Implementations.loadWithXhr = function(url, responseType, method, data, headers, deferred, overrideMimeType) {
         var dataUriRegexResult = dataUriRegex.exec(url);
         if (dataUriRegexResult !== null) {
             deferred.resolve(decodeDataUri(dataUriRegexResult, responseType));
             return;
         }
 
+        if (FeatureDetection.isNodeJs()) {
+            loadWithHttpRequest(url, responseType, method, data, headers, deferred, overrideMimeType);
+            return;
+        }
+
         var xhr = new XMLHttpRequest();
 
         if (TrustedServers.contains(url)) {

Source/Core/getAbsoluteUri.js

@@ -23,7 +23,12 @@ define([
      * var absoluteUri = Cesium.getAbsoluteUri('awesome.png', 'https://test.com');
      */
     function getAbsoluteUri(relative, base) {
-        return getAbsoluteUri._implementation(relative, base, document);
+        var documentObject;
+        if (typeof document !== 'undefined') {
+            documentObject = document;
+        }
+
+        return getAbsoluteUri._implementation(relative, base, documentObject);
     }
 
     getAbsoluteUri._implementation = function(relative, base, documentObject) {
@@ -32,7 +37,14 @@ define([
             throw new DeveloperError('relative uri is required.');
         }
         //>>includeEnd('debug');
-        base = defaultValue(base, defaultValue(documentObject.baseURI, documentObject.location.href));
+
+        if (!defined(base)) {
+            if (typeof documentObject === 'undefined') {
+                return relative;
+            }
+            base = defaultValue(documentObject.baseURI, documentObject.location.href);
+        }
+
         var baseUri = new Uri(base);
         var relativeUri = new Uri(relative);
         return relativeUri.resolve(baseUri).toString();

Specs/Core/FeatureDetectionSpec.js

@@ -110,4 +110,8 @@ defineSuite([
             expect(FeatureDetection.imageRenderingValue()).not.toBeDefined();
         }
     });
+
+    it('detects Node.js', function() {
+        expect(FeatureDetection.isNodeJs()).toBe(false);
+    });
 });