org.apache.turbine.modules
Class ActionEvent

java.lang.Object
  org.apache.turbine.modules.Assembler
      org.apache.turbine.modules.Action
          org.apache.turbine.modules.ActionEvent

Direct Known Subclasses:

VelocityActionEvent

public abstract class ActionEvent

extends Action

This is an alternative to the Action class that allows you to do event based actions. Essentially, you label all your submit buttons with the prefix of "eventSubmit_" and the suffix of "methodName". For example, "eventSubmit_doDelete". Then any class that subclasses this class will get its "doDelete(RunData data)" method executed. If for any reason, it was not able to execute the method, it will fall back to executing the doPeform() method which is required to be implemented.

Limitations:

Because ParameterParser makes all the key values lowercase, we have to do some work to format the string into a method name. For example, a button name eventSubmit_doDelete gets converted into eventsubmit_dodelete. Thus, we need to form some sort of naming convention so that dodelete can be turned into doDelete.

Thus, the convention is this:

• The variable name MUST have the prefix "eventSubmit_".
• The variable name after the prefix MUST begin with the letters "do".
• The first letter after the "do" will be capitalized and the rest will be lowercase

If you follow these conventions, then you should be ok with your method naming in your Action class.

Version:

$Id: ActionEvent.java 534527 2007-05-02 16:10:59Z tv $

Author:

Jon S. Stevens , Henning P. Schmiedehausen, Quinton McCombs

Field Summary

protected static java.lang.String	BUTTON The name of the button to look for.
protected static int	BUTTON_LENGTH The length of the button to look for.
protected static int	LENGTH The length of the button to look for.
protected org.apache.commons.logging.Log	log Logging
protected static int	METHOD_NAME_LENGTH The length of the method name.
protected static java.lang.String	METHOD_NAME_PREFIX The prefix of the method name.

Constructor Summary

ActionEvent()
C'tor

Method Summary

protected boolean	considerKey(java.lang.String key, ParameterParser pp) Checks whether the selected key really is a valid event.
abstract void	doPerform(RunData data) You need to implement this in your classes that extend this class.
void	executeEvents(RunData data) This method should be called to execute the event based system.
protected java.lang.String	formatString(java.lang.String input) This method does the conversion of the lowercase method name into the proper case.
protected void	perform(RunData data) This overrides the default Action.perform() to execute the doEvent() method.

Methods inherited from class java.lang.Object

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

Field Detail

log

protected org.apache.commons.logging.Log log

Logging

BUTTON

protected static final java.lang.String BUTTON

The name of the button to look for.

See Also:

Constant Field Values

BUTTON_LENGTH

protected static final int BUTTON_LENGTH

The length of the button to look for.

METHOD_NAME_PREFIX

protected static final java.lang.String METHOD_NAME_PREFIX

The prefix of the method name.

See Also:

Constant Field Values

METHOD_NAME_LENGTH

protected static final int METHOD_NAME_LENGTH

The length of the method name.

LENGTH

protected static final int LENGTH

The length of the button to look for.

Constructor Detail

ActionEvent

public ActionEvent()

C'tor

Method Detail

doPerform

public abstract void doPerform(RunData data)
                        throws java.lang.Exception

You need to implement this in your classes that extend this class.

Specified by:

doPerform in class Action

Parameters:

data - Turbine information.

Throws:

java.lang.Exception - a generic exception.

perform

protected void perform(RunData data)
                throws java.lang.Exception

This overrides the default Action.perform() to execute the doEvent() method. If that fails, then it will execute the doPerform() method instead.

Overrides:

perform in class Action

Parameters:

data - Turbine information.

Throws:

java.lang.Exception - a generic exception.

executeEvents

public void executeEvents(RunData data)
                   throws java.lang.Exception

This method should be called to execute the event based system.

Parameters:

data - Turbine information.

Throws:

java.lang.Exception - a generic exception.

formatString

protected final java.lang.String formatString(java.lang.String input)

This method does the conversion of the lowercase method name into the proper case.

Parameters:

input - The unconverted method name.

Returns:

A string with the method name in the proper case.

considerKey

protected boolean considerKey(java.lang.String key,
                              ParameterParser pp)

Checks whether the selected key really is a valid event.

Parameters:

key - The selected key

pp - The parameter parser to look for the key value

Returns:

true if this key is really an ActionEvent Key