fixviewstate.unminified.js

/*
 * Copyright OmniFaces
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 */
/**
 * <p>Fix JSF view state if necessary. In Mojarra, it get lost on certain forms during certain ajax updates (e.g. 
 * updating content which in turn contains another form). When this script is loaded <em>after</em> the standard jsf.js
 * script containing standard JSF ajax API, then it will be automatically applied on all JSF ajax requests.
 * <pre>
 * &lt;h:outputScript library="javax.faces" name="jsf.js" target="head" /&gt;
 * &lt;h:outputScript library="omnifaces" name="fixviewstate.js" target="head" /&gt;
 * </pre>
 * <p>This script also recognizes jQuery ajax API as used by some component libraries such as PrimeFaces, it will then
 * be automatically applied on all jQuery ajax requests.
 * <pre>
 * &lt;h:outputScript library="primefaces" name="jquery/jquery.js" target="head" /&gt;
 * &lt;h:outputScript library="omnifaces" name="fixviewstate.js" target="head" /&gt;
 * </pre>
 * <p>Explicit declaration of jsf.js or jquery.js is not necessary. In that case you need to put the 
 * <code>&lt;h:outputScript&gt;</code> tag inside the <code>&lt;h:body&gt;</code> to ensure that it's loaded 
 * <em>after</em> the JSF and/or jQuery script.
 * <p>In case your JSF component library doesn't utilize standard JSF nor jQuery ajax API, but a proprietary one, and
 * exposes the missing view state problem, then you can still apply this script manually during the "complete" event of
 * the ajax request whereby the concrete <code>XMLHttpRequest</code> instance is available as some argument as follows:
 * <pre>
 * function someOncompleteCallbackFunction(xhr) {
 *     OmniFaces.FixViewState.apply(xhr.responseXML);
 * });
 * </pre>
 * <p>This was scheduled to be fixed in JSF 2.2 spec, however it was postponed to JSF 2.3. Note that this fix is not
 * necessary for MyFaces as they have internally already fixed it for long in their jsf.js.
 * 
 * @author Bauke Scholtz
 * @link https://github.com/javaee/javaserverfaces-spec/issues/790
 * @since 1.7
 * @deprecated Since 3.0 as this is already fixed in JSF 2.3.
 */
OmniFaces.FixViewState = (function(window, document) {

	// "Constant" fields ----------------------------------------------------------------------------------------------

	var VIEW_STATE_REGEX = new RegExp("^([\\w]+:)?" + OmniFaces.VIEW_STATE_PARAM.replace(/\./g, "\\.") + "(:[0-9]+)?$");

	// Private static fields ------------------------------------------------------------------------------------------

	var self = {};

	// Public static functions ----------------------------------------------------------------------------------------

	/**
	 * Apply the "fix view state" on the current document based on the given XML response.
	 * @param {Document} responseXML The XML response of the XMLHttpRequest.
	 */
	self.apply = function(responseXML) {
		if (typeof responseXML === "undefined") {
			return;
		}

		var viewStateValue = getViewStateValue(responseXML);

		if (!viewStateValue) {
			return;
		}

		for (var i = 0; i < document.forms.length; i++) {
			var form = document.forms[i];
			var viewStateElement = form[OmniFaces.VIEW_STATE_PARAM];

			if (form.method == "post" && !viewStateElement) {
				// This POST form doesn't have a view state. This isn't right. Create it.
				createViewStateElement(form, viewStateValue);
			}
		}
	}

	// Private static functions ---------------------------------------------------------------------------------------

	/**
	 * Returns the view state value from the given XML response.
	 * @param {Document} responseXML The XML response of the XMLHttpRequest.
	 * @return {string} The view state value from the given XML response.
	 */
	function getViewStateValue(responseXML) {
		var updates = responseXML.getElementsByTagName("update");

		for (var i = 0; i < updates.length; i++) {
			var update = updates[i];
			
			if (VIEW_STATE_REGEX.exec(update.getAttribute("id"))) {
				return update.textContent || update.innerText;
			}
		}

		return null;
	}

	/**
	 * Create view state hidden input element with given view state value and add it to given form.
	 * @param {HTMLFormElement} form The form to add the view state hidden input element to.
	 * @param {string} viewStateValue The view state value to be added to the newly created view state hidden input element.
	 */
	function createViewStateElement(form, viewStateValue) {
		var hidden;

		try {
			hidden = document.createElement("<input name='" + OmniFaces.VIEW_STATE_PARAM + "'>"); // IE6-8.
		}
		catch(e) {
			hidden = document.createElement("input");
			hidden.setAttribute("name", OmniFaces.VIEW_STATE_PARAM);
		}

		hidden.setAttribute("type", "hidden");
		hidden.setAttribute("value", viewStateValue);
		hidden.setAttribute("autocomplete", "off");
		form.appendChild(hidden);
	}

	// Global initialization ------------------------------------------------------------------------------------------

	if (window.jsf) { // Standard JSF ajax API present?
		jsf.ajax.addOnEvent(function(data) {
			if (data.status == "success") {
				self.apply(data.responseXML);
			}
		});
	}

	if (window.jQuery) { // jQuery ajax API present?
		jQuery(document).ajaxComplete(function(event, xhr) {
			if (typeof xhr !== "undefined") {
				self.apply(xhr.responseXML);
			}
		});
	}
	
	// Expose self to public ------------------------------------------------------------------------------------------

	return self;

})(window, document);