DateTag

package org.apache.maven.continuum.web.view.jsp.ui;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.TextProvider;
import com.opensymphony.xwork2.util.ValueStack;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;

import javax.servlet.jsp.JspException;

import org.apache.struts2.views.jsp.ui.TextareaTag;

/**
 * First attempt at creating a date tag for the webwork framework. The tag will
 * format a date by using either a specified format attribute, or by falling
 * back on to a globally defined 'webwork.date' property.
 * When nice="true" is specified, it will return a human readable string (in 2 hours, 3 minutes).
 * <p/>
 * From http://jira.opensymphony.com/browse/WW-805
 *
 * @author <a href="mailto:philip.luppens@gmail.com">Philip Luppens</a>
 */
public class DateTag
    extends TextareaTag
{
    /*
     * the name of our property which we will use if the optional format
     * parameter is not specified.
     */
    public final static String DATETAG_PROPERTY = "webwork.date";

    public final static String DATETAG_PROPERTY_PAST = "webwork.date.format.past";

    public final static String DATETAG_DEFAULT_PAST = "{0} ago";

    public final static String DATETAG_PROPERTY_FUTURE = "webwork.date.format.future";

    public final static String DATETAG_DEFAULT_FUTURE = "in {0}";

    public final static String DATETAG_PROPERTY_SECONDS = "webwork.date.format.seconds";

    public final static String DATETAG_DEFAULT_SECONDS = "an instant";

    public final static String DATETAG_PROPERTY_MINUTES = "webwork.date.format.minutes";

    public final static String DATETAG_DEFAULT_MINUTES = "{0,choice,1#one minute|1<{0} minutes}";

    public final static String DATETAG_PROPERTY_HOURS = "webwork.date.format.hours";

    public final static String DATETAG_DEFAULT_HOURS =
        "{0,choice,1#one hour|1<{0} hours}{1,choice,0#|1#, one minute|1<, {1} minutes}";

    public final static String DATETAG_PROPERTY_DAYS = "webwork.date.format.days";

    public final static String DATETAG_DEFAULT_DAYS =
        "{0,choice,1#one day|1<{0} days}{1,choice,0#|1#, one hour|1<, {1} hours}";

    public final static String DATETAG_PROPERTY_YEARS = "webwork.date.format.years";

    public final static String DATETAG_DEFAULT_YEARS =
        "{0,choice,1#one year|1<{0} years}{1,choice,0#|1#, one day|1<, {1} days}";

    //our optional format parameter
    private String format;

    private String nameAttr;

    private boolean nice;

    private Date date;

    private TextProvider tp;

    public int doEndTag()
        throws JspException
    {
        String actualName = findString( nameAttr );
        String msg = null;
        ValueStack stack = getStack();
        //find the name on the valueStack, and cast it to a date
        Object dateObj = stack.findValue( actualName );

        if ( dateObj != null )
        {
            if ( dateObj instanceof Date )
            {
                date = (Date) dateObj;
            }
            else if ( dateObj instanceof Long )
            {
                Calendar cal = Calendar.getInstance();
                cal.setTimeInMillis( (Long) dateObj );
                date = cal.getTime();
            }
            else
            {
                throw new JspException( "Could not cast the requested object " + nameAttr + " to a java.util.Date" );
            }
        }

        if ( date != null && date.getTime() > 0 )
        {
            tp = findProviderInStack();

            if ( tp == null )
            {
                throw new JspException( "Could not find a TextProvider on the stack." );
            }

            if ( nice )
            {
                msg = formatTime( date );
            }
            else
            {
                if ( format == null )
                {
                    String globalFormat;
                    //if the format is not specified, fall back using the defined
                    // property DATETAG_PROPERTY

                    globalFormat = tp.getText( DATETAG_PROPERTY );

                    if ( globalFormat != null )
                    {
                        msg =
                            new SimpleDateFormat( globalFormat, ActionContext.getContext().getLocale() ).format( date );
                    }
                    else
                    {
                        //fall back using the xwork date format ?
                    }
                }
                else
                {
                    msg = new SimpleDateFormat( format, ActionContext.getContext().getLocale() ).format( date );
                }
            }
        }

        if ( msg != null )
        {
            try
            {
                //if we used the id attribute, we will store the formatted date
                // in the valuestack, otherwise, we write it to the
                // outputstream.
                if ( getId() == null )
                {
                    pageContext.getOut().write( msg );
                }
                else
                {
                    stack.getContext().put( getId(), msg );
                }
            }
            catch ( IOException e )
            {
                throw new JspException( e );
            }
        }
        return EVAL_PAGE;
    }

    private TextProvider findProviderInStack()
    {
        for ( Object o : getStack().getRoot() )
        {
            if ( o instanceof TextProvider )
            {
                return (TextProvider) o;
            }

        }
        return null;
    }

    public String formatTime( Date date )
    {
        StringBuffer sb = new StringBuffer();
        List<Object> args = new ArrayList<Object>();
        long secs = ( new Date().getTime() - date.getTime() ) / 1000;
        long mins = secs / 60;
        int min = (int) mins % 60;
        long hours = mins / 60;
        int hour = (int) hours % 24;
        int days = (int) hours / 24;
        int day = days % 365;
        int years = days / 365;

        if ( Math.abs( secs ) < 60 )
        {
            args.add( secs );
            args.add( sb );
            args.add( null );
            sb.append( tp.getText( DATETAG_PROPERTY_SECONDS, DATETAG_DEFAULT_SECONDS, args ) );

        }
        else if ( hours == 0 )
        {
            args.add( (long) min );
            args.add( sb );
            args.add( null );
            sb.append( tp.getText( DATETAG_PROPERTY_MINUTES, DATETAG_DEFAULT_MINUTES, args ) );

        }
        else if ( days == 0 )
        {
            args.add( (long) hour );
            args.add( (long) min );
            args.add( sb );
            args.add( null );
            sb.append( tp.getText( DATETAG_PROPERTY_HOURS, DATETAG_DEFAULT_HOURS, args ) );
        }
        else if ( years == 0 )
        {
            args.add( (long) days );
            args.add( (long) hour );
            args.add( sb );
            args.add( null );
            sb.append( tp.getText( DATETAG_PROPERTY_DAYS, DATETAG_DEFAULT_DAYS, args ) );
        }
        else
        {
            args.add( new Object[]{(long) years} );
            args.add( new Object[]{(long) day} );
            args.add( sb );
            args.add( null );

            sb.append( tp.getText( DATETAG_PROPERTY_YEARS, DATETAG_DEFAULT_YEARS, args ) );
        }
        args.clear();
        args.add( sb.toString() );
        if ( date.before( new Date() ) )
        {
            //looks like this date is passed
            return tp.getText( DATETAG_PROPERTY_PAST, DATETAG_DEFAULT_PAST, args );
        }
        else
        {
            return tp.getText( DATETAG_PROPERTY_FUTURE, DATETAG_DEFAULT_FUTURE, args );
        }
    }

    public void setName( String name )
    {
        this.nameAttr = name;
    }

    public String getFormat()
    {
        return format;
    }

    public void setFormat( String format )
    {
        this.format = format;
    }

    public boolean isNice()
    {
        return nice;
    }

    public void setNice( boolean nice )
    {
        this.nice = nice;
    }
}