features.js

define(["requirejs-dplugins/has"], function (has) {
	// Flag for whether to create background iframe behind popups like Menus and Dialog.
	// A background iframe is useful to prevent problems with popups appearing behind applets/pdf files.
	has.add("config-bgIframe", false);

	// Flag to enable advanced bidi support
	has.add("bidi", false);

	// Flag to enable inheritance direction from any ancestor
	has.add("inherited-dir", false);

	if (typeof window !== "undefined") {
		// Returns the name of the method to test if an element matches a CSS selector.
		has.add("dom-matches", function () {
			var node = document.body;
			if (node.matches) {
				return "matches";
			}
			if (node.webkitMatchesSelector) {
				return "webkitMatchesSelector";
			}
			if (node.mozMatchesSelector) {
				return "mozMatchesSelector";
			}
			if (node.msMatchesSelector) {
				return "msMatchesSelector";
			}
		});

		// Does platform have native support for document.registerElement() or a polyfill to simulate it?
		has.add("document-register-element", !!document.registerElement);

		// Test for how to monitor DOM nodes being inserted and removed from the document.
		// For DOMNodeInserted events, there are two variations:
		//		"root" - just notified about the root of each tree added to the document
		//		"all" - notified about all nodes added to the document
		has.add("MutationObserver", window.MutationObserver ? "MutationObserver" : window.WebKitMutationObserver ?
			"WebKitMutationObserver" : "");
		has.add("DOMNodeInserted", function () {
			var root = document.createElement("div"),
				child = document.createElement("div"),
				sawRoot, sawChild;
			root.id = "root";
			child.id = "child";
			root.appendChild(child);

			function listener(event) {
				if (event.target.id === "root") {
					sawRoot = true;
				}
				if (event.target.id === "child") {
					sawChild = true;
				}
			}

			document.body.addEventListener("DOMNodeInserted", listener);
			document.body.appendChild(root);
			document.body.removeChild(root);
			document.body.removeEventListener("DOMNodeInserted", listener);
			return sawChild ? "all" : sawRoot ? "root" : "";
		});

		// Can we use __proto__ to reset the prototype of DOMNodes?
		// It's not available on IE<11, and even on IE11 it makes the node's attributes
		// (ex: node.attributes, node.textContent) disappear, so disabling it on IE11 too.
		has.add("dom-proto-set", function () {
			var node = document.createElement("div");
			/* jshint camelcase: false */
			/* jshint proto: true */
			if (!node.__proto__) {
				return false;
			}
			node.__proto__ = {};
			/* jshint camelcase: true */
			/* jshint proto: false */
			return !!node.attributes;
		});

		// Support for <template> elements (specifically, that their content is available via templateNode.content
		// rather than templateNode.children[] etc.
		has.add("dom-template", !!document.createElement("template").content);
	}

	return has;
});