FacesUtils.java

/*
 * Copyright 2006-2012 ICEsoft Technologies Inc.
 *
 * 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
 *
 *       http://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.
 */
package org.icepdf.examples.jsf.viewer.util;

import javax.faces.FactoryFinder;
import javax.faces.application.Application;
import javax.faces.application.ApplicationFactory;
import javax.faces.application.FacesMessage;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import javax.faces.el.ValueBinding;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

/**
 * JSF utilities.
 *
 * @since 3.0
 */
public class FacesUtils {
    /**
     * Get servlet context.
     *
     * @return the servlet context
     */
    public static ServletContext getServletContext() {
        return (ServletContext) FacesContext.getCurrentInstance().getExternalContext().getContext();
    }

    public static String getContextParam(String contextParam){
        return getServletContext().getInitParameter(contextParam);
    }

    public static ExternalContext getExternalContext() {
        FacesContext fc = FacesContext.getCurrentInstance();
        return fc.getExternalContext();
    }

    public static HttpSession getHttpSession(boolean create) {
        return (HttpSession) FacesContext.getCurrentInstance().
                getExternalContext().getSession(create);
    }

    /**
     * Get managed bean based on the bean name.
     *
     * @param beanName the bean name
     * @return the managed bean associated with the bean name
     */
    public static Object getManagedBean(String beanName) {

        return getValueBinding(getJsfEl(beanName)).getValue(FacesContext.getCurrentInstance());
    }

    /**
     * Remove the managed bean based on the bean name.
     *
     * @param beanName the bean name of the managed bean to be removed
     */
    public static void resetManagedBean(String beanName) {
        getValueBinding(getJsfEl(beanName)).setValue(FacesContext.getCurrentInstance(), null);
    }

    /**
     * Store the managed bean inside the session scope.
     *
     * @param beanName    the name of the managed bean to be stored
     * @param managedBean the managed bean to be stored
     */
    public static void setManagedBeanInSession(String beanName, Object managedBean) {
        FacesContext.getCurrentInstance().getExternalContext().getSessionMap().put(beanName, managedBean);
    }

    /**
     * Get parameter value from request scope.
     *
     * @param name the name of the parameter
     * @return the parameter value
     */
    public static String getRequestParameter(String name) {
        return (String) FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap().get(name);
    }

    /**
     * Add information message.
     *
     * @param msg the information message
     */
    public static void addInfoMessage(String msg) {
        addInfoMessage(null, msg);
    }

    /**
     * Add information message to a specific client.
     *
     * @param clientId the client id
     * @param msg      the information message
     */
    public static void addInfoMessage(String clientId, String msg) {
        FacesContext.getCurrentInstance().addMessage(clientId, new FacesMessage(FacesMessage.SEVERITY_INFO, msg, msg));
    }

    /**
     * Add error message.
     *
     * @param msg the error message
     */
    public static void addErrorMessage(String msg) {
        addErrorMessage(null, msg);
    }

    /**
     * Add error message to a specific client.
     *
     * @param clientId the client id
     * @param msg      the error message
     */
    public static void addErrorMessage(String clientId, String msg) {
        FacesContext.getCurrentInstance().addMessage(clientId, new FacesMessage(FacesMessage.SEVERITY_ERROR, msg, msg));
    }

    private static Application getApplication() {
        ApplicationFactory appFactory = (ApplicationFactory) FactoryFinder.getFactory(FactoryFinder.APPLICATION_FACTORY);
        return appFactory.getApplication();
    }

    private static ValueBinding getValueBinding(String el) {
        return getApplication().createValueBinding(el);
    }

    private static HttpServletRequest getServletRequest() {
        return (HttpServletRequest) FacesContext.getCurrentInstance().getExternalContext().getRequest();
    }

    private static Object getElValue(String el) {
        return getValueBinding(el).getValue(FacesContext.getCurrentInstance());
    }

    private static String getJsfEl(String value) {
        return "#{" + value + "}";
    }
}