Documentation for the Utility Tag Library

1. INTRODUCTION

The utility custom tag library contains examples of some basic tags. It illustrates several custom tag library code techniques.

2. PREREQUISITE SOFTWARE

This custom tag library requires no software other than a servlet container that supports the JavaServer Pages Specification, version 1.1.

3. CONFIGURATION INFORMATION

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

• Copy the tag library descriptor file (utility/utility.tld) to the /WEB-INF subdirectory of your web application.
• Copy the tag library JAR file (utility/utility.jar) 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/utility</taglib-uri>
          <taglib-location>/WEB-INF/utility.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/utility" prefix="x" %>

4. TAG DOCUMENTATION

The utility Tag Library contains the following tags:

1. Hello Tag

   The Hello tag prints out the text "Hello World". It does not have any attributes.

   Attribute	Description	Required
   -	-	-

   
   

2. Copy Tag

   The MacroCopy tag copies the attribute text to a Writer.

   Attribute	Description	Required
   name	Name associated with the text to be copied. Any string value.	yes

   
   

3. Paste Tag

   The MacroPaste tag pastes the text specified by a Writer.

   Attribute	Description	Required
   name	Name associated with the text to be pasted. Any string value.	yes

   
   

4. ShowSource Tag

   The ShowSource tag takes a jspFile and copies the contents to a Writer.

   Attribute	Description	Required
   jspFile	The filename and relative path of the jsp file. Any string value.	yes

   
   

5. Include Tag

   The Include tag includes in-line the output of the specified url.

   Attribute	Description	Required
   url	Any valid url.	yes

   
   

6. If Tag

   The If tag is a basic conditional tag.

   Attribute	Description	Required
   predicate	Any string value.	yes

   
   

7. For Tag

   The For tag is a basic looping tag.

   Attribute	Description	Required
   iterations	Number of loop iterations to be completed. Any string integer value.	yes
   varName	Variable name associated with the For loop. Any string value.	no
   begin	Loop starting value. Any string integer value.	no

   
   

8. useBean Tag

   The useBean tag associates an instance of a Java object with the given id.

   Either the classname or type must be specified.

   The beanName and classname attributes are mutually exclusive, you can't specify both.

   Attribute	Description	Required
   id	Uniquely identifies the bean to the JSP container and page. Any string value.	yes
   scope	page|request|session|application	no
   classname	name of class that defines the implementation of the object.	no
   type	type of the scripting variable defined	no
   beanName	The name of the bean as expected by the instantiate() method of the java.beans.Beans class	no
   processRequest	true|false. JSP 0.92 compatibility.	no

   
   

9. Validate Tag

   The Validate tag generates Javascript to validate the HTML form.

   Attribute	Description	Required
   name	Name of the form. Any string value.	yes
   method	Name of the Javascript function to be generated. Any string value.	yes
   reqdFields	Comma separated mandatory field list. Any string value.	yes