macros.java

这个weblogging 设计得比较精巧

package org.roller.presentation.velocity;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.runtime.RuntimeSingleton;
import org.roller.model.RefererManager;
import org.roller.model.UserManager;
import org.roller.pojos.PageData;
import org.roller.pojos.RefererData;
import org.roller.pojos.UserData;
import org.roller.pojos.WeblogCategoryData;
import org.roller.pojos.WebsiteData;
import org.roller.presentation.RollerContext;
import org.roller.presentation.RollerRequest;
import org.roller.presentation.bookmarks.tags.ViewBookmarksTag;
import org.roller.presentation.tags.menu.EditorNavigationBarTag;
import org.roller.presentation.tags.menu.NavigationBarTag;
import org.roller.presentation.weblog.tags.RssBadgeTag;
import org.roller.presentation.weblog.tags.ViewWeblogEntriesTag;
import org.roller.presentation.weblog.tags.WeblogCategoryChooserTag;
import org.roller.util.Utilities;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.List;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.PageContext;
import org.roller.config.RollerRuntimeConfig;
import org.roller.model.RollerFactory;

/**
 * Provides the macros object that is available to Roller templates and 
 * weblog entries.
 */
public class Macros
{
    private static Log mLogger = 
        LogFactory.getFactory().getInstance(Macros.class);

    protected PageContext mPageContext = null;
    
    protected PageHelper mPageHelper = null;

    /** Maximum depth of recursion for includePage and showWeblogEntry calls */
    public static final int MAX_RECURSION_DEPTH = 6;
    
    /** Keep track of each thread's recursive depth in includePage(). */
    protected static final ThreadLocal mIncludePageTLS = new ThreadLocal();
    
    /** Keep track of each thread's recursive depth in showWeblogEntries(s */
    protected static final ThreadLocal mEntriesTLS = new ThreadLocal();
    
    /** Keep track of each thread's recursive depth in showWeblogEntries(s */
    protected static final ThreadLocal mEntriesDayTLS = new ThreadLocal();

    //------------------------------------------------------------------------
    /** Construts a macros object for a JSP page context. */
    public Macros( PageContext ctx, PageHelper helper )
    {
        mPageContext = ctx;
        mPageHelper = helper;
    }

    //------------------------------------------------------------------------
    /** Get the Roller request object associated with this instance */
    protected RollerRequest getRollerRequest()
    {
        return RollerRequest.getRollerRequest(mPageContext);
    }

    //------------------------------------------------------------------------
    /**
     * Returns the current date formatted according to the specified pattern.
     * @param pattern Date pattern, @see java.text.SimpleDateFormat
     * @return Current date formatted according to specified pattern.
     */
    public String formatCurrentDate( String pattern )
    {
        String date = null;
        try
        {
            SimpleDateFormat format = new SimpleDateFormat( pattern );
            date = format.format( new Date() );
        }
        catch (RuntimeException e)
        {
            date = "ERROR: formatting date";
        }
        return date;
    }

    //------------------------------------------------------------------------
    /**
     * Returns most recent update time of collection of weblog entries using
     * the specified pattern.
     * @param weblogEntries Collection of weblog entries.
     * @param Date format pattern, @see java.text.SimpleDateFormat.
     * @return Most recent update time formatted by pattern.
     */
    public String formatUpdateTime( ArrayList weblogEntries, String pattern )
    {
        String date = null;
        Date updateTime = getUpdateTime(weblogEntries);
        try
        {
            SimpleDateFormat format = new SimpleDateFormat( pattern );
            date = format.format( updateTime );
        }
        catch (RuntimeException e)
        {
            date = "ERROR: formatting date";
        }
        return date;
    }
   
    //------------------------------------------------------------------------
    /**
     * Returns most recent update time of collection of weblog entries.
     * @param weblogEntries Collection of weblog entries.
     * @return Most recent update time.
     */
    public Date getUpdateTime( ArrayList weblogEntries )
    {
        return PageModel.getUpdateTime( weblogEntries );
    }
   
    //------------------------------------------------------------------------
    /**
     * Version number of Roller.
     * @return Version number of Roller.
     */
    public String showVersion()
    {
        ServletContext ctx = mPageContext.getServletContext();
        return ctx.getInitParameter( RollerContext.VERSION_KEY );
    }
    //------------------------------------------------------------------------
    /**
     * Title of your website.
     * @return Title of your website.
     */
    public String showWebsiteTitle()
    {
        WebsiteData wd = null;
        RollerRequest rreq = getRollerRequest();
        try {
            wd = rreq.getWebsite();
        }
        catch (Exception e) {
            return "ERROR finding website in request: " + e.toString();
        }
        return wd.getName();
    }
    //------------------------------------------------------------------------
    /**
     * Website description.
     * @return Website description.
     */
    public String showWebsiteDescription()
    {
        WebsiteData wd = null;
        RollerRequest rreq = getRollerRequest();
        try {
            wd = rreq.getWebsite();
        }
        catch (Exception e) {
            return "ERROR finding website in request: " + e.toString();
        }
        return wd.getDescription();
    }
    //------------------------------------------------------------------------
    /**
     * Show navigation links for pages that are not hidden.
     * @param vertical Display links in a vertical column, separated by BR tags.
     * @return HTML for navigation bar.
     */
    public String showNavBar( boolean vertical )
    {
        NavigationBarTag navTag = new NavigationBarTag();
        navTag.setPageContext(mPageContext);
        navTag.setVertical(vertical);
        return navTag.emit();
    }
    //------------------------------------------------------------------------
    /**
     * Show navigation links for pages that are not hidden, separated by a
     * specified delimeter.
     * @param vertical Display links in a vertical column.
     * @param delimeter Delimeter to separate links.
     * @return HTML for navigation bar.
     */
    public String showNavBar( boolean vertical, String delimiter )
    {
        NavigationBarTag navTag = new NavigationBarTag();
        navTag.setPageContext(mPageContext);
        navTag.setVertical(vertical);
        navTag.setDelimiter(delimiter);
        return navTag.emit();
    }
    //------------------------------------------------------------------------
    /**
     * Show the Roller Editor menu as a navigation bar.
     * specified delimeter.
     * @param vertical Displaylinks in a vertical column.
     * @return HTML for navigation bar.
     * */
    public String showEditorNavBar( boolean vertical )
    {
        EditorNavigationBarTag editorTag = new EditorNavigationBarTag();
        editorTag.setPageContext(mPageContext);
        if ( vertical )
        {
            editorTag.setView("/navbar-vertical.vm");
        }
        else
        {
            editorTag.setView("/navbar-horizontal.vm");
        }
        editorTag.setModel("editor-menu.xml");
        return editorTag.emit();
    }

    //------------------------------------------------------------------------

    /**
     * Display bookmarks in specified folder using specified title.
     * @param folderName Folder to be dislayed.
     * @param title Title to be displayed.
     * @return HTML for bookmarks display.
     */
    public String showBookmarks( String folderName, String title )
    {
        ViewBookmarksTag booksTag = new ViewBookmarksTag();
        booksTag.setPageContext(mPageContext);
        return booksTag.view( folderName, title );
    }

    /**
     * Display bookmarks in specified folder using specified title.
     * @param folderName Folder to be dislayed.
     * @param showFolderName Display folder name as title.
     * @return HTML for bookmarks display.
     */
    public String showBookmarks( String folderName, boolean showFolderName )
    {
        ViewBookmarksTag booksTag = new ViewBookmarksTag();
        booksTag.setPageContext(mPageContext);
        return booksTag.view( folderName, showFolderName );
    }

    /**
     * Display bookmarks in specified folder as an expandable link.
     * @param folderName Folder to be dislayed.
     * @param showFolderName Display folder name as title.
     * @param expandingFolder Show bookmarks in expanding folder.
     * @return HTML and JavaScript for bookmarks display.
     */
    public String showBookmarks(
        String folderName, boolean showFolderName, boolean expandingFolder )
    {
        ViewBookmarksTag booksTag = new ViewBookmarksTag();
        booksTag.setPageContext(mPageContext);
        return booksTag.view( folderName, showFolderName, expandingFolder );
    }

    //------------------------------------------------------------------------
    /**
     * Get {@link org.roller.pojos.UserData UserData} object.
     * @see org.roller.pojos.UserData
     * @return User object.
     */
    public UserData getUser()
    {
        try
        {
            return getRollerRequest().getUser();
        }
        catch (Exception e)
        {
            mLogger.error("Getting user",e); 
        }
        return null;
    }

    //------------------------------------------------------------------------
    /**
     * Get  
     * {@link org.roller.presentation.users.WebsiteDataEx WebsiteDataEx} 
     * object.
     * @see org.roller.pojos.WebsiteData
     * @return Website object.
     */
    public WebsiteData getWebsite()
    {
        try
        {
            return getRollerRequest().getWebsite();
        }
        catch (Exception e)
        {
            mLogger.error("Getting website",e); 
        }
        return null;
    }

    //------------------------------------------------------------------------
    /**
     * Show weblog enties using the day template specified in your site 
     * settings.
     * @return HTML for weblog entries.
     */    
    public String showWeblogEntries()
    {
        return showWeblogEntries(15);
    }

    //------------------------------------------------------------------------
    /**
     * Show up to 100 weblog enties using the day template specified in your site 
     * settings.
     * @param maxEntries Maximum number of entries to display.
     * @return HTML for weblog entries.
     */    
    public String showWeblogEntries(int maxEntries)
    {
        String ret = null;
        try
        {
            // protection from recursion
            if ( mEntriesTLS.get() == null )
            {
                mEntriesTLS.set( new Integer(0) );
            }
            else
            {
                Integer countObj = (Integer)mEntriesTLS.get();
                int count = countObj.intValue();
                if ( count++ > MAX_RECURSION_DEPTH )
                {
                    return "ERROR: recursion level too deep";
                }
                mEntriesTLS.set( new Integer(count) );
            }

            ViewWeblogEntriesTag entriesTag = new ViewWeblogEntriesTag();
            entriesTag.setPageContext(mPageContext);
            entriesTag.setMaxEntries(maxEntries);
            ret = entriesTag.emit();
        }
        finally
        {
            mEntriesTLS.set( null );
        }

        return ret;