Jakarta Project: Unstandard Tag library

Version: 1.0

Overview
Requirements
Configuration
Tag Summary
Tag Reference
Examples
Javadocs
Revision History

Overview

Your unstandard description summary.

This JSP tag library can be used to ....

etc....

Requirements

This custom tag library requires no software other than a servlet container that supports the JavaServer Pages Specification, version 1.1 or higher. Plus any requirements for additional API packages.

Configuration

Follow these steps to configure your web application with this tag library:

Copy the tag library descriptor file to the /WEB-INF subdirectory of your web application.
Copy the tag library JAR file to the /WEB-INF/lib subdirectory of your web application.

Add a <taglib> element to your web application deployment descriptor in /WEB-INF/web.xml like this:

<taglib>
  <taglib-uri>http://jakarta.apache.org/taglibs/unstandard-1.0</taglib-uri>
  <taglib-location>/WEB-INF/unstandard.tld</taglib-location>
</taglib>

To use the tags from this library in your JSP pages, add the following directive at the top of each page:

<%@ taglib uri="http://jakarta.apache.org/taglibs/unstandard-1.0" prefix="un" %>

where "un" is the tag name prefix you wish to use for tags from this library. You can change this value to any prefix you like.

Tag Summary

Unstandard Tags

equals	Equals compares two strings
instanceOf	InstanceOf compares an object with a type
invoke	Invokes a method upon a target object
bind	Bind a variable from a Java class into the context
size	Work out the size of a String, Collection, Map or Object[]
useConstants	Expose Java class constants as a map of values

Tag Reference

equals				Availability: 1.0
Equals compares two strings
Tag Body	empty
Restrictions	None
Attributes	Name	Required	Runtime Expression Evaluation	Availability
	var	No	No
	Attribute description
	ignoreCase	No	No
	Attribute description
	lhs	Yes	No
	Attribute description
	rhs	Yes	No
	Attribute description
Variables	Name		Scope	Availability
	var attribute value		Start of tag to end of page	1.0
	Equals result
	Properties	None
Examples	Here is a comment.
	<% File tempdir = (File)application.getAttribute ("javax.servlet.context.tempdir"); %> <% String echoLog = tempdir+"/echoAppendLog.txt";%> <% String messageString = "Hello World. The time is: " + time+System.getProperty("line.separator"); %> `<foo:bar attr1="<%= expr %>" attr2="val2" attr3="<%= expr2 %>" />`

instanceOf				Availability: 1.0
InstanceOf takes an object and a string and sets the attribute named by "var" to true or false depending on the results
Tag Body	empty
Restrictions	None
Attributes	Name	Required	Runtime Expression Evaluation	Availability
	var	No	No
	Attribute description
	value	Yes	No
	Attribute description
	type	Yes	No
	Attribute description
Variables	Name		Scope	Availability
	var attribute value		Start of tag to end of page	1.0
	Equals result
	Properties	None
Examples	Here is a comment.
	<% File tempdir = (File)application.getAttribute ("javax.servlet.context.tempdir"); %> <% String echoLog = tempdir+"/echoAppendLog.txt";%> <% String messageString = "Hello World. The time is: " + time+System.getProperty("line.separator"); %> `<foo:bar attr1="<%= expr %>" attr2="val2" attr3="<%= expr2 %>" />`

invoke				Availability: 1.0
Invokes a method upon a target object
Tag Body	empty
Restrictions	None
Attributes	Name	Required	Runtime Expression Evaluation	Availability
	var	Yes	No
	Attribute description
	target	Yes	No
	Target to invoke the method upon
	method	Yes	No
	The method to invoke
Variables	Name		Scope	Availability
	var attribute value		Start of tag to end of page	1.0
	Invoke method on an object
	Properties	None
Examples	None

bind				Availability: 1.0
Bind a variable from a Java class into the context
Tag Body	empty
Restrictions	None
Attributes	Name	Required	Runtime Expression Evaluation	Availability
	var	Yes	No
	Attribute description
	target	No	No
	Target to get the value from
	type	No	No
	For static attributes, target may not be specified and instead type may be specified
	field	Yes	No
	The field to get
Variables	Name		Scope	Availability
	var attribute value		Start of tag to end of page	1.0
	Bind a variable from a Java class into the context
	Properties	None
Examples	None

size				Availability: 1.0
Work out the size of a String, Collection, Map or Object[]
Tag Body	empty
Restrictions	None
Attributes	Name	Required	Runtime Expression Evaluation	Availability
	var	Yes	No
	Attribute description
	target	No	No
	Target to get the value from
Variables	Name		Scope	Availability
	var attribute value		Start of tag to end of page	1.0
	The variable into which the length may be put
	Properties	None
Examples	None

useConstants				Availability: 1.0
Exposes all of the public constants in a class as a map stored in a scoped attribute. The scope may be specified, but defaults to page scope.
Tag Body	empty
Restrictions	None
Attributes	Name	Required	Runtime Expression Evaluation	Availability
	var	Yes	No
	Name of the scoped attribute into which the map will be stored.
	className	Yes	No
	Fully qualified name of the class from which constants will be extracted.
	scope	No	No
	Scope into which to store the map. Default is page scope.
Variables	Name		Scope	Availability
	var attribute value		Start of tag to end of page	1.0
	The name of the attribute into which the map will be stored.
	Properties	None
Examples	To expose all of the constants in the Integer class:
	`<un:useConstants var="const" className="java.lang.Integer" />`

Examples

See the example application unstandard-examples.war for examples of the usage of the tags from this custom tag library.

Java Docs

Java programmers can view the java class documentation for this tag library as javadocs.

Revision History

Review the complete revision history of this tag library.