Package 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
  Description
  `protected boolean`
  `pushed`
  `protected String`
  `value`

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

  `actionMapper, attributes, COMPONENT_STACK, devMode, escapeHtmlBody, performClearTagStateForTagPoolingServers, stack, standardAttributesMap, throwExceptionOnELFailure`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `Push(ValueStack stack)`

- ## Method Summary

  Modifier and Type
  Method
  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

  `addAllAttributes, addParameter, completeExpression, copyAttributes, determineActionURL, determineNamespace, end, escapeHtmlBody, fieldError, findAncestor, findString, findString, findValue, findValue, findValue, getAttributes, getComponentStack, getNamespace, getPerformClearTagStateForTagPoolingServers, getStack, getStandardAttributes, isAcceptableExpression, isValidTagAttribute, popComponentStack, setActionMapper, setDevMode, setEscapeHtmlBody, setNotExcludedAcceptedPatterns, setPerformClearTagStateForTagPoolingServers, setThrowExceptionsOnELFailure, setUrlHelper, stripExpression, toString, usesBody`

  ### Methods inherited from class java.lang.Object

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

- ## Field Details

  - ### value

    protected String value

  - ### pushed

    protected boolean pushed

- ## Constructor Details

  - ### Push

    public Push(ValueStack stack)

- ## Method Details

  - ### 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)