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WODirectAction


Inherits from: NSObject
Package: com.apple.yellow.webobjects

Class Description

WODirectAction is an abstract class that defines the interface for direct action classes. You subclass WODirectAction to provide an object that is a repository for action methods.

WODirectAction provides the simplest interface for addig logic and custom code to your WebObjects application. WODirectAction objects are instantiated when a URL requested by a client browser is sent to your WebObjects application. The WODirectActionRequestHandler determines the proper class and action to be invoked and then passes control to your WODirectAction subclass.

In contrast to a WOComponent-based action, a direct action is well-defined by the URL that invokes it. For example, the following URL will invoke the method findEmployeeAction on the subclass of WODirectAtion called Common: 

http://localhost/cgi-bin/WebObjects/Myapp.woa/wa/Common/findEmployee

A subclass of WODirectAction is a repository for action methods. New WebObjects applications contain a default implementation of the WODirectAction subclass called DirectAction. The DirectAction class is used when no class is specified in the URL.

In summary, here are some URLs and the actions they invoke:


This URL... Invokes this method...
../MyApp.woa/wa/ defaultAction on class DirectAction
../MyApp.woa/wa/ find findAction on classDirectAction , if it exists defaultAction on class find , otherwise
../MyApp.woa/wa/Common/find findAction on class Common

WODirectActionRequestHandler invokes methods only on subclasses on WODirectAction. If the specified class or action doesn't exist, WODirectActionRequestHandler throws an exception.




Method Types

Constructors
WODirectAction
Obtaining attributes
request
Obtaining a session
existingSession
session
Obtaining a page
pageWithName
Performing an action
performActionNamed
Value assignment
takeFormValueArraysForKeyArray
takeFormValuesForKeyArray
Debugging
debugString
logString


Constructors


WODirectAction

public WODirectAction(WORequest aWORequest)

Subclasses must override to provide any additional initialization.


Static Methods


debugString

public static void debugString(String aString)

This method is similar to logString except that you can control whether it displays output with the WODebuggingEnabled user default option. If WODebuggingEnabled is YES, then the debugString messages display their output. If WODebuggingEnabled is NO, the debugString messages don't display their output.

logString

public static void logString(String aString)

Prints a message to the standard error device (stderr). The message can include formatted variable data using String's concatenation feature, for example:
int i = 500;

float f = 2.045;

WOComponent.logString("Amount = " + i + ", Rate = " + f ", Total = " + i*f);



Instance Methods


existingSession

public WOSession existingSession()

Restores the session based on the request. If the request did not have a session ID or the session ID referred to a non-existent session, then this method returns null. To determine if a session failed to restore, check the request's session ID to see if it non-null and if so, call this method to check its result.

See Also: session


pageWithName

public WOComponent pageWithName(String aComponentName)

Returns the WOComponent with the specified name.

performActionNamed

public WOActionResults performActionNamed(String anActionName)

Performs the action with the specified name and returns the result of that action. The default implementation appends "Action" to anActionName and tries to invoke resulting method name. Override this method to change how actions are dispatched.

request

public WORequest request()

Returns the WORequest object that initiated the action.

session

public WOSession session()

Returns the current session. If there is no session, this method first tries to restore the session that the request's session ID refers to. If the request has no session ID-which is a possibility if the application is written entirely with direct actions-this method creates a new session and returns it. If the session ID refers to a session that doesn't exist or cannot be restored, this method throws an exception.

See Also: existingSession


takeFormValueArraysForKeyArray

public void takeFormValueArraysForKeyArray(NSArray aKeyArray)

Performs takeValueForKey on each key in aKeyArray using values from the receiver's request.

This method uses an NSArray for each form value. This is useful when a user can select multiple items for a form value, such as a WOBrowser. If a form value contains only one item, this method uses an NSArray with one object. To use single objects as form values, use takeFormValuesForKeyArray.

See Also: takeFormValueArraysForKeys:


takeFormValuesForKeyArray

public void takeFormValuesForKeyArray(NSArray aKeyArray)

Performs takeValueForKey on the each key in aKeyArray using values from the receiver's request.

This method uses an a single object for each form value. If a form value contains more than one item, such as a WOBrowser, this method uses the first item in the array. To use arrays of objects as form values, use takeFormValueArraysForKeyArray.

See Also: takeFormValuesForKeys:



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