org.apache.velocity.app.tools.VelocityFormatter Maven / Gradle / Ivy
package org.apache.velocity.app.tools;
/*
* 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 java.lang.reflect.Array;
import java.text.DateFormat;
import java.util.Date;
import java.util.List;
import org.apache.velocity.context.Context;
/**
* Formatting tool for inserting into the Velocity WebContext. Can
* format dates or lists of objects.
*
* Here's an example of some uses:
*
*
* $formatter.formatShortDate($object.Date)
* $formatter.formatLongDate($db.getRecord(232).getDate())
* $formatter.formatArray($array)
* $formatter.limitLen(30, $object.Description)
*
DateFormat.SHORT style.
*
* @param date The date to format.
* @return The formatted date as text.
*/
public String formatShortDate(Date date)
{
return DateFormat.getDateInstance(DateFormat.SHORT).format(date);
}
/**
* Formats a date in DateFormat.LONG style.
*
* @param date The date to format.
* @return The formatted date as text.
*/
public String formatLongDate(Date date)
{
return DateFormat.getDateInstance(DateFormat.LONG).format(date);
}
/**
* Formats a date/time in 'short' style.
*
* @param date The date to format.
* @return The formatted date as text.
*/
public String formatShortDateTime(Date date)
{
return DateFormat
.getDateTimeInstance(DateFormat.SHORT,
DateFormat.SHORT).format(date);
}
/**
* Formats a date/time in 'long' style.
*
* @param date The date to format.
* @return The formatted date as text.
*/
public String formatLongDateTime(Date date)
{
return DateFormat.getDateTimeInstance(
DateFormat.LONG, DateFormat.LONG).format(date);
}
/**
* Formats an array into the form "A, B and C".
*
* @param array An Object.
* @return A String.
*/
public String formatArray(Object array)
{
return formatArray(array, ", ", " and ");
}
/**
* Formats an array into the form
* "A<delim>B<delim>C".
*
* @param array An Object.
* @param delim A String.
* @return A String.
*/
public String formatArray(Object array,
String delim)
{
return formatArray(array, delim, delim);
}
/**
* Formats an array into the form
* "A<delim>B<finaldelim>C".
*
* @param array An Object.
* @param delim A String.
* @param finaldelim A String.
* @return A String.
*/
public String formatArray(Object array,
String delim,
String finaldelim)
{
StringBuffer sb = new StringBuffer();
int arrayLen = Array.getLength(array);
for (int i = 0; i < arrayLen; i++)
{
// Use the Array.get method as this will automatically
// wrap primitive types in a suitable Object-derived
// wrapper if necessary.
sb.append(Array.get(array, i).toString());
if (i < arrayLen - 2)
{
sb.append(delim);
}
else if (i < arrayLen - 1)
{
sb.append(finaldelim);
}
}
return sb.toString();
}
/**
* Formats a vector into the form "A, B and C".
*
* @param list The list of elements to format.
* @return A String.
*/
public String formatVector(List list)
{
return formatVector(list, ", ", " and ");
}
/**
* Formats a vector into the form "A<delim>B<delim>C".
*
* @param list The list of elements to format.
* @param delim A String.
* @return A String.
*/
public String formatVector(List list,
String delim)
{
return formatVector(list, delim, delim);
}
/**
* Formats a list into the form
* "Adelim>B<finaldelim>C".
*
* @param list The list of elements to format.
* @param delim A String.
* @param finaldelim A String.
* @return A String.
*/
public String formatVector(List list,
String delim,
String finaldelim)
{
StringBuffer sb = new StringBuffer();
int size = list.size();
for (int i = 0; i < size; i++)
{
sb.append(list.get(i));
if (i < size - 2)
{
sb.append(delim);
}
else if (i < size - 1)
{
sb.append(finaldelim);
}
}
return sb.toString();
}
/**
* Limits 'string' to 'maxlen' characters. If the string gets
* curtailed, "..." is appended to it.
*
* @param maxlen An int with the maximum length.
* @param string A String.
* @return A String.
*/
public String limitLen(int maxlen,
String string)
{
return limitLen(maxlen, string, "...");
}
/**
* Limits 'string' to 'maxlen' character. If the string gets
* curtailed, 'suffix' is appended to it.
*
* @param maxlen An int with the maximum length.
* @param string A String.
* @param suffix A String.
* @return A String.
*/
public String limitLen(int maxlen,
String string,
String suffix)
{
String ret = string;
if (string.length() > maxlen)
{
ret = string.substring(0, maxlen - suffix.length()) + suffix;
}
return ret;
}
/**
* Class that returns alternating values in a template. It stores
* a list of alternate Strings, whenever alternate() is called it
* switches to the next in the list. The current alternate is
* retrieved through toString() - i.e. just by referencing the
* object in a Velocity template. For an example of usage see the
* makeAlternator() method below.
*/
public class VelocityAlternator
{
/**
*
*/
protected String[] alternates = null;
/**
*
*/
protected int current = 0;
/**
* Constructor takes an array of Strings.
*
* @param alternates A String[].
*/
public VelocityAlternator(String[] alternates)
{
this.alternates = alternates;
}
/**
* Alternates to the next in the list.
*
* @return The current alternate in the sequence.
*/
public String alternate()
{
current++;
current %= alternates.length;
return "";
}
/**
* Returns the current alternate.
*
* @return A String.
*/
public String toString()
{
return alternates[current];
}
}
/**
* As VelocityAlternator, but calls alternate()
* automatically on rendering in a template.
*/
public class VelocityAutoAlternator extends VelocityAlternator
{
/**
* Constructor takes an array of Strings.
*
* @param alternates A String[].
*/
public VelocityAutoAlternator(String[] alternates)
{
super(alternates);
}
/**
* Returns the current alternate, and automatically alternates
* to the next alternate in its sequence (trigged upon
* rendering).
*
* @return The current alternate in the sequence.
*/
public final String toString()
{
String s = alternates[current];
alternate();
return s;
}
}
/**
* Makes an alternator object that alternates between two values.
*
*
Example usage in a Velocity template:
*
*
* <table>
* $formatter.makeAlternator("rowcolor", "#c0c0c0", "#e0e0e0")
* #foreach $item in $items
* #begin
* <tr><td bgcolor="$rowcolor">$item.Name</td></tr>
* $rowcolor.alternate()
* #end
* </table>
*