    001/*
    002    Licensed to the Apache Software Foundation (ASF) under one
    003    or more contributor license agreements.  See the NOTICE file
    004    distributed with this work for additional information
    005    regarding copyright ownership.  The ASF licenses this file
    006    to you under the Apache License, Version 2.0 (the
    007    "License"); you may not use this file except in compliance
    008    with the License.  You may obtain a copy of the License at
    009
    010       http://www.apache.org/licenses/LICENSE-2.0
    011
    012    Unless required by applicable law or agreed to in writing,
    013    software distributed under the License is distributed on an
    014    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    015    KIND, either express or implied.  See the License for the
    016    specific language governing permissions and limitations
    017    under the License.
    018 */
    019
    020package org.apache.wiki.filters;
    021
    022import org.apache.wiki.api.core.Context;
    023import org.apache.wiki.api.core.Engine;
    024import org.apache.wiki.api.exceptions.FilterException;
    025import org.apache.wiki.api.filters.BasePageFilter;
    026import org.apache.wiki.event.WikiEventListener;
    027import org.apache.wiki.event.WikiEventManager;
    028import org.apache.wiki.event.WikiPageEvent;
    029
    030import java.util.Properties;
    031import org.apache.wiki.security.EventUtil;
    032
    033/**
    034  * Fires WikiPageEvents for page events.
    035  * <p>
    036  * Adding a PageEventFilter to the FilterManager will automatically attach an event delegate with the WikiEventManager to provide for
    037  * firing and listener management. All that remains is then adding the listener to the filter via the WikiEventManager. This is quite
    038  * simple:
    039  * </p>
    040  * <pre>
    041  *    PageEventFilter filter = new PageEventFilter();
    042  *    engine.getFilterManager().addPageFilter(filter,5000);
    043  *    // attach listener to filter
    044  *    WikiEventManager.addWikiEventListener(filter,listener);
    045  * </pre>
    046  * <p>
    047  * This class provides convenience methods for adding and removing WikiEventListeners.
    048  * </p>
    049  *
    050  * @see org.apache.wiki.event.WikiEventManager
    051  */
    052public class PageEventFilter extends BasePageFilter {
    053
    054    /**
    055     * Called whenever a new PageFilter is instantiated and reset.
    056     */
    057    @Override
    058    public void initialize( final Engine engine, final Properties properties ) throws FilterException {
    059        super.initialize( engine, properties );
    060    }
    061
    062    /**
    063     * This method is called whenever a page has been loaded from the provider, but not yet been sent through the TranslatorReader.
    064     * Note that you cannot do HTML translation here, because TranslatorReader is likely to escape it.
    065     *
    066     * @param wikiContext The current wikicontext.
    067     * @param content WikiMarkup.
    068     */
    069    @Override
    070    public String preTranslate( final Context wikiContext, final String content ) {
    071        fireEvent( WikiPageEvent.PRE_TRANSLATE, wikiContext );
    072        return content;
    073    }
    074
    075
    076    /**
    077     * This method is called after a page has been fed through the TranslatorReader, so anything you are seeing here is translated content.
    078     * If you want to do any of your own WikiMarkup2HTML translation, do it here.
    079     */
    080    @Override
    081    public String postTranslate( final Context wikiContext, final String htmlContent ) {
    082        fireEvent( WikiPageEvent.POST_TRANSLATE, wikiContext );
    083        return htmlContent;
    084    }
    085
    086
    087    /**
    088      * This method is called before the page has been saved to the PageProvider.
    089      */
    090    @Override
    091    public String preSave( final Context wikiContext, final String content ) {
    092        fireEvent( WikiPageEvent.PRE_SAVE, wikiContext );
    093        return content;
    094    }
    095
    096
    097    /**
    098      * This method is called after the page has been successfully saved. If the saving fails for any reason, then this method will not
    099      * be called.
    100      * <p>
    101      * Since the result is discarded from this method, this is only useful for things like counters, etc.
    102      */
    103    @Override
    104    public void postSave( final Context wikiContext, final String content ) {
    105        fireEvent( WikiPageEvent.POST_SAVE, wikiContext );
    106    }
    107
    108
    109    // events processing .......................................................
    110
    111    /**
    112     *  Registers a WikiEventListener with this instance. This is a convenience method.
    113     *
    114     * @param listener the event listener
    115     */
    116    public final synchronized void addWikiEventListener( final WikiEventListener listener ) {
    117        WikiEventManager.addWikiEventListener( this, listener );
    118    }
    119
    120    /**
    121     *  Un-registers a WikiEventListener with this instance. This is a convenience method.
    122     *
    123     * @param listener the event listener
    124     */
    125    public final synchronized void removeWikiEventListener( final WikiEventListener listener ) {
    126        WikiEventManager.removeWikiEventListener( this, listener );
    127    }
    128
    129    /**
    130     *  Fires a WikiPageEvent of the provided type and page name to all registered listeners. Only <tt>PAGE_LOCK</tt> and
    131     *  <tt>PAGE_UNLOCK</tt> event types will fire an event; other event types are ignored.
    132     *
    133     * @see org.apache.wiki.event.WikiPageEvent
    134     * @param type      the WikiPageEvent type to be fired.
    135     * @param context   the WikiContext of the event.
    136     */
    137    protected final void fireEvent( final int type, final Context context ) {
    138        if( WikiEventManager.isListening(this ) && WikiPageEvent.isValidType( type ) ) {
    139            final WikiPageEvent event = new WikiPageEvent( context.getEngine(), type, context.getPage().getName() );
    140            EventUtil.applyFrom(event, context);
    141            WikiEventManager.fireEvent(this, event );
    142        }
    143    }
    144
    145}