er.extensions.components._private
Class ERXWORepetition

java.lang.Object
  com.webobjects.appserver.WOElement
      com.webobjects.appserver.WODynamicElement
          com.webobjects.appserver._private.WODynamicGroup
              er.extensions.components._private.ERXWORepetition

public class ERXWORepetition
extends com.webobjects.appserver._private.WODynamicGroup

Replacement for WORepetition. It is installed via ERXPatcher.setClassForName(ERXWORepetition.class, "WORepetition") into the runtime system, so you don't need to reference it explicitly.

• adds support for List and java.lang.Array, in addition to NSArray and Vector (which is a List in 1.4). This is listed as Radar #3325342 since June 2003.
• help with backtracking issues by adding not only the current index, but also the current object's hash code to the element id, so it looks like "x.y.12345.z".
  If they don't match when invokeAction is called, the list is searched for a matching object. If none is found, then:
  • if the property er.extensions.ERXWORepetition.raiseOnUnmatchedObject=true - an ERXWORepetition.UnmatchedObjectException is thrown
  • if notFoundMarker is bound, that is used for the item in the repetition. This can be used to flag special handling in the action method, possibly useful for Ajax requests
  • otherwise, the action is ignored
  This feature is turned on globally if er.extensions.ERXWORepetition.checkHashCodes=true or on a per-component basis by setting the checkHashCodes binding to true or false.
  Known issues:
  • you can't re-generate your list by creating new objects between the appendToReponse and the next takeValuesFromRequest unless you use uniqueKey and the value for that key is consistent across the object instances
    When doing this by fetching EOs, this is should not a be problem, as the EO most probably has the same hashCode if the EC stays the same.
  • Your moved object should still be in the list.
  • Form values are currently not fixed, which may lead to NullpointerExceptions or other failures. However, if they happen, by default you would have used the wrong values, so it may be arguable that having an error is better...
  Note that this implementation adds a small amount of overhead due to the creation of the Context for each RR phase, but this is preferable to having to give so many parameters. As an alternative to the default use of System.identityHashCode to unique your items, you can set the binding "uniqueKey" to be a string keypath on your items that can return a unique key for the item. For instance, if you are using ERXGenericRecord, you can set uniqueKey = "rawPrimaryKey"; if your EO has an integer primary key, and this will make the uniquing value be the primary key instead of the hash code. While this reveals the primary keys of your items, the set of possible valid matches is still restricted to only those that were in the list to begin with, so no additional capabilities are available to users. uniqueKey does not have to return an integer.

  Author:

  ak

  Bindings

  list	the array or list of items to iterate over
  item	the current item in the iteration
  count	the total number of items to iterate over
  index	the current index in the iteration
  uniqueKey	a String keypath on item (relative to item, not relative to the component) returning a value whose toString() is unique for this component
  checkHashCodes	if true, checks the validity of repetition references during the RR loop
  raiseOnUnmatchedObject	if true, an exception is thrown when the repetition does not find a matching object
  debugHashCodes	if true, prints out hashcodes for each entry in the repetition as it is traversed
  batchFetch	a comma-separated list of keypaths on the "list" array binding to batch fetch
  eoSupport	try to use globalIDs to determine the hashCode for EOs
  notFoundMarker	used for the item in the repetition if checkHashCodes is true, don't bind directly to null as that will be translated to false

  Nested Class Summary

  protected class	ERXWORepetition.Context WOElements must be reentrant, so we need a context object or will have to add the parameters to every method.
  static class	ERXWORepetition.UnmatchedObjectException

  Field Summary

  protected com.webobjects.appserver.WOAssociation	_batchFetch
  protected com.webobjects.appserver.WOAssociation	_checkHashCodes
  protected com.webobjects.appserver.WOAssociation	_count
  protected com.webobjects.appserver.WOAssociation	_debugHashCodes
  protected com.webobjects.appserver.WOAssociation	_eoSupport
  protected com.webobjects.appserver.WOAssociation	_index
  protected com.webobjects.appserver.WOAssociation	_item
  protected com.webobjects.appserver.WOAssociation	_list
  protected com.webobjects.appserver.WOAssociation	_notFoundMarker
  protected com.webobjects.appserver.WOAssociation	_raiseOnUnmatchedObject
  protected com.webobjects.appserver.WOAssociation	_uniqueKey

  Fields inherited from class com.webobjects.appserver._private.WODynamicGroup

  _children

  Fields inherited from class com.webobjects.appserver.WODynamicElement

  _ConstructorParameters

  Constructor Summary

  ERXWORepetition(java.lang.String string, com.webobjects.foundation.NSDictionary associations, com.webobjects.appserver.WOElement woelement)
  Designated Constructor.

  Method Summary

  protected void	_cleanupAfterIteration(int i, com.webobjects.appserver.WOContext wocontext, com.webobjects.appserver.WOComponent wocomponent) Cleans the WOContext after the loop iteration.
  protected int	_count(ERXWORepetition.Context context, com.webobjects.appserver.WOComponent wocomponent)
  protected void	_failCreation(java.lang.String message) Utility to throw an exception if the bindings are incomplete.
  protected java.lang.String	_indexOfChosenItem(com.webobjects.appserver.WORequest worequest, com.webobjects.appserver.WOContext wocontext)
  protected java.lang.String	_indexStringForSenderAndElement(java.lang.String senderID, java.lang.String elementID) Fills the context with the object given in the "list" binding.
  protected void	_prepareForIterationWithIndex(ERXWORepetition.Context context, int index, com.webobjects.appserver.WOContext wocontext, com.webobjects.appserver.WOComponent wocomponent, boolean checkHashCodes) Prepares the WOContext for the loop iteration.
  void	appendToResponse(com.webobjects.appserver.WOResponse woresponse, com.webobjects.appserver.WOContext wocontext)
  protected ERXWORepetition.Context	createContext(com.webobjects.appserver.WOComponent wocomponent)
  com.webobjects.appserver.WOActionResults	invokeAction(com.webobjects.appserver.WORequest worequest, com.webobjects.appserver.WOContext wocontext)
  void	takeValuesFromRequest(com.webobjects.appserver.WORequest worequest, com.webobjects.appserver.WOContext wocontext)
  java.lang.String	toString() Human readable description.

  Methods inherited from class com.webobjects.appserver._private.WODynamicGroup

  addChildElement, appendChildrenToResponse, childrenElements, EmptyGroup, hasChildrenElements, invokeChildrenAction, takeChildrenValuesFromRequest

  Methods inherited from class java.lang.Object

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

  Field Detail

  _list

  protected com.webobjects.appserver.WOAssociation _list

  _item

  protected com.webobjects.appserver.WOAssociation _item

  _count

  protected com.webobjects.appserver.WOAssociation _count

  _index

  protected com.webobjects.appserver.WOAssociation _index

  _uniqueKey

  protected com.webobjects.appserver.WOAssociation _uniqueKey

  _checkHashCodes

  protected com.webobjects.appserver.WOAssociation _checkHashCodes

  _raiseOnUnmatchedObject

  protected com.webobjects.appserver.WOAssociation _raiseOnUnmatchedObject

  _eoSupport

  protected com.webobjects.appserver.WOAssociation _eoSupport

  _debugHashCodes

  protected com.webobjects.appserver.WOAssociation _debugHashCodes

  _batchFetch

  protected com.webobjects.appserver.WOAssociation _batchFetch

  _notFoundMarker

  protected com.webobjects.appserver.WOAssociation _notFoundMarker

  Constructor Detail

  ERXWORepetition

  public ERXWORepetition(java.lang.String string,
                         com.webobjects.foundation.NSDictionary associations,
                         com.webobjects.appserver.WOElement woelement)

  Designated Constructor. Gets called by the template parser. Checks if the bindings are valid.

  Method Detail

  _failCreation

  protected void _failCreation(java.lang.String message)

  Utility to throw an exception if the bindings are incomplete.

  toString

  public java.lang.String toString()

  Human readable description.

  Overrides:

  toString in class com.webobjects.appserver._private.WODynamicGroup

  _prepareForIterationWithIndex

  protected void _prepareForIterationWithIndex(ERXWORepetition.Context context,
                                               int index,
                                               com.webobjects.appserver.WOContext wocontext,
                                               com.webobjects.appserver.WOComponent wocomponent,
                                               boolean checkHashCodes)

  Prepares the WOContext for the loop iteration.

  Parameters:

  checkHashCodes -

  _cleanupAfterIteration

  protected void _cleanupAfterIteration(int i,
                                        com.webobjects.appserver.WOContext wocontext,
                                        com.webobjects.appserver.WOComponent wocomponent)

  Cleans the WOContext after the loop iteration.

  _indexStringForSenderAndElement

  protected java.lang.String _indexStringForSenderAndElement(java.lang.String senderID,
                                                             java.lang.String elementID)

  Fills the context with the object given in the "list" binding.

  _indexOfChosenItem

  protected java.lang.String _indexOfChosenItem(com.webobjects.appserver.WORequest worequest,
                                                com.webobjects.appserver.WOContext wocontext)

  _count

  protected int _count(ERXWORepetition.Context context,
                       com.webobjects.appserver.WOComponent wocomponent)

  createContext

  protected ERXWORepetition.Context createContext(com.webobjects.appserver.WOComponent wocomponent)

  takeValuesFromRequest

  public void takeValuesFromRequest(com.webobjects.appserver.WORequest worequest,
                                    com.webobjects.appserver.WOContext wocontext)

  Overrides:

  takeValuesFromRequest in class com.webobjects.appserver._private.WODynamicGroup

  invokeAction

  public com.webobjects.appserver.WOActionResults invokeAction(com.webobjects.appserver.WORequest worequest,
                                                               com.webobjects.appserver.WOContext wocontext)

  Overrides:

  invokeAction in class com.webobjects.appserver._private.WODynamicGroup

  appendToResponse

  public void appendToResponse(com.webobjects.appserver.WOResponse woresponse,
                               com.webobjects.appserver.WOContext wocontext)

  Overrides:

  appendToResponse in class com.webobjects.appserver._private.WODynamicGroup