Skip to main content

Struts2 - Control Tags


In this section we are going to discuss the various control tags ( The Control Tags are used for flow control such as if, else and iterate.)

'If' tag could be used by itself or with 'Else If' Tag and/or single/multiple 'Else' Tag. Create a JSP page IfControlTag.jsp.

Set a property 'technologyName' with a value 'Java' as 
<s:set name="technologyName" value="%{'Java'}"/>


Among if, elseif and else tags only one tag evaluates at a time. Evaluation is based upon the conditions being processed. Evaluated conditions must be of Boolean type. This is illustrated in the following Jsp page.

[Note:If the condition in tag evaluates to 'true' then only this tag is evaluated and others are discarded. As illustrated in the example.
If the condition in tag evaluates to 'false' and tag evaluates to 'true' then the body of the tag is processed.
If the condition in tag and tags evaluates to 'false' then only the tag is processed. ]

IfControlTag.jsp

<%@ taglib prefix="s" uri="/struts-tags" %>
<html> <head>
<title>Struts 2 Control Tag Example</title> </head>
<body> <s:set name="technologyName" value="%{'Java'}"/>
<s:if test="%{#technologyName=='Java'}"> <div>
<s:property value="%{#technologyName}" /></div>
</s:if>
<s:elseif test="%{#technologyName=='Jav'}"> <div>
<s:property value="%{#technologyName}" /></div>
</s:elseif>
<s:else> <div>
Technology Value is not Java</div>
</s:else>
</body> 
</html>

struts.xml: Add the following xml snippet in the struts.xml file.

<action name="doIf" >
<result>/pages/genericTags/IfControlTag.jsp</result> </action>

index.jsp: Add the following jsp snippet in the index.jsp file.

<ul>
<li><a href="roseindia/doIf.action">IF Control Tag Example</a></li> </ul>

In the IfControlTag.jsp only tag evaluates to true

<s:if test="%{#technologyName=='Java'}"> <div><s:property value="%{#technologyName}" /></div> </s:if>


So we get the output equal to Java
Labels:

Comments

Post a Comment

Popular posts from this blog

Struts2 - Textfield Tag (Form Tags)

In this section, we are going to describe the textfield tag. The textfield tag is a UI tag that is used to render an HTML input field of type text. Add the following code snippet into the struts.xml file. struts.xml <action name="submitTag">   <result>/pages/uiTags/submitTag.jsp</result> </action> Create a jsp using the tag <s:textfield >  that renders an HTML input field of type text. <s:textfield label="Employee Name" name="empname" size="15" maxlength="10" /> tag displays an HTML text field with label equal to Employee Name with length of 15 columns. textfieldTag.jsp <%@ taglib prefix="s" uri="/struts-tags" %> <html>   <head>   <title>Textfield Tag Example</title>   </head>   <body>   <h1><span style="background-color: #FFFFcc">Tex...
Post a Comment
Read more

Struts2 - Optgroup Tag (Form Tags)

In this section, we are going to describe the optgroup tag. The optgroup tag is a UI tag that creates an optgroup component which needs to reside within a select tag <s:select>. Add the following code snippet into the struts.xml file. struts.xml <action name="optgroupTag">    <result>/pages/uiTags/optgroupTag.jsp</result> </action> Create a jsp using the tag <s:optgroup> within the <s:select> tag. It creates an optgroup component. This tag contains few parameters: The label parameter sets the label attribute In our case we have set it to " Hardware " and " Software ". optgroupTag.jsp <%@ taglib prefix="s" uri="/struts-tags" %> <html>   <head>   <title>Optgroup Tag Example!</title>    </head>   <body>  <h1><span style="background-color: #FFFFcc">Optgroup Tag Ex...
Read more

Struts2 - Combobox Tag (Form Tags)

The struts2 combobox is basically an HTML INPUT of type text and HTML SELECT grouped together to give you a combo box functionality. You can place text in the INPUT control by using the SELECT control or type it in directly in the text field. Add the following code snippet into the struts.xml file. struts.xml <action name="comboboxTag" class="net.struts2.comboboxTag">    <result>/pages/uiTags/comboboxTag.jsp</result> </action> Create "comboboxTag " action class and a list in the class and populate it with various items as shown in the class. comboboxTag.java package net.struts2; import com.opensymphony.xwork2.ActionSupport; import java.util.*; public class comboboxTag extends ActionSupport{      private List fruits;   public String execute()throws Exception{   fruits = new ArrayList();   fruits.add("Appl...
2 comments
Read more