org.apache.struts2.components

Class Push

java.lang.Object

org.apache.struts2.components.Component

org.apache.struts2.components.Push

public class Push
extends Component

Push value on stack for simplified usage.

• value* (Object) - value to be pushed into the top of the stack

Examples

 
 <s:push value="user">
     <s:propery value="firstName" />
     <s:propery value="lastName" />
 </s:push>
 
 

Pushed user into the stack, and hence property tag could access user's properties (firstName, lastName etc) since user is now at the top of the stack

 
  <s:push value="myObject">                              ----- (1)
       <s:bean name="jp.SomeBean" var="myBean"/>        ----- (2)
          <s:param name="myParam" value="top"/>        ----- (3)
       </s:bean>
   </s:push>
 
 

 
 when in (1), myObject is at the top of the stack
 when in (2), jp.SomeBean is in the top of stack, also in stack's context with key myBean
 when in (3), top will get the jp.SomeBean instance
 
 

 
 <s:push value="myObject">                                       ---(A)
    <s:bean name="jp.SomeBean" var="myBean"/>                   ---(B)
       <s:param name="myParam" value="top.mySomeOtherValue"/>  ---(C)
    </s:bean>
 </s:push>
 
 

 
 when in (A), myObject is at the top of the stack
 when in (B), jp.SomeBean is at the top of the stack, also in context with key myBean
 when in (C), top refers to jp.SomeBean instance. so top.mySomeOtherValue would invoke SomeBean's mySomeOtherValue() method
 
 

 
 <s:push value="myObject">                                 ---- (i)
    <s:bean name="jp.SomeBean" var="myBean"/>             ---- (ii)
       <s:param name="myParam" value="[1].top"/>         -----(iii)
    </s:bean>
 </s:push>
 
 

 
 when in (i), myObject is at the top of the stack
 when in (ii), jp.SomeBean is at the top of the stack, followed by myObject
 when in (iii), [1].top will returned top of the cut of stack starting from myObject, namely myObject itself
 
 

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	pushed
protected String	value

Fields inherited from class org.apache.struts2.components.Component

actionMapper, COMPONENT_STACK, devMode, parameters, stack, standardAttributesMap, throwExceptionOnELFailure

Constructor Summary

Constructors

Constructor and Description
Push(ValueStack stack)

Method Summary

Modifier and Type	Method and Description
boolean	end(Writer writer, String body) Callback for the end tag of this component.
void	setValue(String value)
boolean	start(Writer writer) Callback for the start tag of this component.

Methods inherited from class org.apache.struts2.components.Component

addAllParameters, addParameter, altSyntax, completeExpressionIfAltSyntax, copyParams, determineActionURL, determineNamespace, end, escapeHtmlBody, fieldError, findAncestor, findString, findString, findStringIfAltSyntax, findValue, findValue, findValue, getComponentStack, getParameters, getStack, getStandardAttributes, isValidTagAttribute, popComponentStack, setActionMapper, setDevMode, setThrowExceptionsOnELFailure, setUrlHelper, stripExpressionIfAltSyntax, toString, usesBody

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

value

protected String value

pushed

protected boolean pushed

Constructor Detail

Push

public Push(ValueStack stack)

Method Detail

start

public boolean start(Writer writer)

Description copied from class: Component

Callback for the start tag of this component. Should the body be evaluated?

Overrides:

start in class Component

Parameters:

writer - the output writer.

Returns:

true if the body should be evaluated

end

public boolean end(Writer writer,
                   String body)

Description copied from class: Component

Callback for the end tag of this component. Should the body be evaluated again?
NOTE: will pop component stack.

Overrides:

end in class Component

Parameters:

writer - the output writer.

body - the rendered body.

Returns:

true if the body should be evaluated again

setValue

public void setValue(String value)