LiveEditClientConfig.java

/*
 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
 *
 * 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.
 *
 * Contributors:
 *     rux, tdelprat
 *
 */

package org.nuxeo.ecm.webapp.liveedit;

import static org.jboss.seam.ScopeType.SESSION;
import static org.jboss.seam.annotations.Install.FRAMEWORK;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import javax.faces.context.FacesContext;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jboss.seam.annotations.Install;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Scope;
import org.nuxeo.runtime.api.Framework;

/**
 * This Seam component is used to represent the client configuration for LiveEdit.
 * <p>
 * On the client side, the LiveEdit plugin advertise its feature via the Accept Header of the browser. This information
 * may be used to decide if LiveEdit links must be displayed or not.
 * <p>
 * The behavior can be configured via the property: org.nuxeo.ecm.platform.liveedit.config
 * <p>
 * There are 3 possible values :
 * <ul>
 * <li>client : let the client choose what is live editable => use the mime-types send by the client to define what must
 * be live editable
 * <li>server : let the server decide => use the mime-type registry define what types are liveEditable
 * <li>both : use client and server intersection => in order to be liveEditable a type must be advertised by the client
 * and set to liveEditable in the mimetypeRegistry
 * </ul>
 * Client advertising is done in the Accept header: Accept : application/x-nuxeo-liveedit:mimetype1;mimetype2 Starting
 * the 5.2, the addon can send the standardized accept header, as Accept :
 * application/x-nuxeo-liveedit;ext0="mimetype1";ext1="mimetype2".. Also, the addon can still send the old way, so the
 * both forms are accepted. See NXP-3257
 *
 * @author Thierry Delprat
 * @author rux
 */
@Scope(SESSION)
@Name("liveEditClientConfig")
@Install(precedence = FRAMEWORK)
public class LiveEditClientConfig implements Serializable {

    private static final long serialVersionUID = 1L;

    private static final Log log = LogFactory.getLog(LiveEditClientConfig.class);

    protected Boolean clientHasLiveEditInstalled;

    protected List<String> advertizedLiveEditableMimeTypes;

    protected static String liveEditConfigPolicy;

    public static final String LE_MIME_TYPE = "application/x-nuxeo-liveedit";

    public static final String LE_CONFIG_PROPERTY = "org.nuxeo.ecm.platform.liveedit.config";

    public static final String LE_CONFIG_CLIENTSIDE = "client";

    public static final String LE_CONFIG_SERVERSIDE = "server";

    public static final String LE_CONFIG_BOTHSIDES = "both";

    protected void detectLiveEditClientConfig() {
        clientHasLiveEditInstalled = false;
        advertizedLiveEditableMimeTypes = new ArrayList<String>();

        if (getLiveEditConfigurationPolicy().equals(LE_CONFIG_SERVERSIDE)) {
            // in case if Server side config, consider liveEdit is installed
            clientHasLiveEditInstalled = true;
            return;
        }

        FacesContext fContext = FacesContext.getCurrentInstance();
        if (fContext == null) {
            log.error("unable to fetch facesContext, can not detect liveEdit client config");
        } else {
            Map<String, String> headers = fContext.getExternalContext().getRequestHeaderMap();
            String accept = headers.get("Accept");
            if (accept == null) {
                return;
            }

            String[] accepted = accept.split(",");
            for (String acceptHeader : accepted) {
                if (acceptHeader != null) {
                    acceptHeader = acceptHeader.trim();
                } else {
                    continue;
                }
                if (acceptHeader.startsWith(LE_MIME_TYPE)) {
                    clientHasLiveEditInstalled = true;
                    String[] subTypes = acceptHeader.split(";");

                    for (String subType : subTypes) {
                        // accept both forms:
                        // application/x-nuxeo-liveedit:mimetype1;mimetype2
                        // application/x-nuxeo-liveedit;ext0="mimetype1";ext1="mimetype2"
                        int equalQuoteIndex = subType.indexOf("=\"");
                        String valueSubType = subType;
                        if (equalQuoteIndex >= 0 && subType.length() > equalQuoteIndex + 3) {
                            valueSubType = subType.substring(equalQuoteIndex + 2, subType.length() - 1);
                        }
                        advertizedLiveEditableMimeTypes.add(valueSubType.replace("!", "/"));
                    }
                }
            }
        }
    }

    public boolean isLiveEditInstalled() {
        if (clientHasLiveEditInstalled == null) {
            detectLiveEditClientConfig();
        }

        return clientHasLiveEditInstalled;
    }

    public String getLiveEditConfigurationPolicy() {
        if (liveEditConfigPolicy == null) {
            liveEditConfigPolicy = Framework.getProperty(LE_CONFIG_PROPERTY, LE_CONFIG_CLIENTSIDE);
        }
        return liveEditConfigPolicy;
    }

    public boolean isMimeTypeLiveEditable(String mimetype) {
        if (advertizedLiveEditableMimeTypes == null) {
            detectLiveEditClientConfig();
        }
        return advertizedLiveEditableMimeTypes.contains(mimetype);
    }

}