uk.co.weft.htform
Class ActionWidget

java.lang.Object
  uk.co.weft.htform.ResourceConsumerImpl
      uk.co.weft.domutil.NodeGeneratorImpl
          uk.co.weft.htform.Widget
              uk.co.weft.htform.ActionWidget

All Implemented Interfaces:

java.lang.Cloneable, NodeGenerator, ResourceConsumer

Direct Known Subclasses:

BasicConfigurator.ConfigureWidget, FirstTime.InitialisationWidget

public class ActionWidget

extends Widget

implements NodeGenerator

An action widget for a hypertext form. Essentially a wrapper around a submit button, but... The theory of it is that the action widget carries it's own action. In practice, of course, because the HTML submit input specification makes the value of the submit input the same as the text on the submit input, there is no actual way of differentiating (at the receiving end) between two submit inputs with the same text.

So, You may have as many ActionWidgets as you like in a Form. If two (or more) do exactly the same thing there's no real harm in their having the same label. But: the despatcher method in the form will pass control to the execute() method of the first ActionWidget which claims it, and the default claim method matches the value against the value of the ActionWidget the user clicked. OK? Got that? You have been warned.

Version:

$Revision: 1.22.4.4 $ This revision: $Author: simon $

Author:

Simon Brooke

Field Summary

static java.lang.String

commandToken

Fields inherited from class uk.co.weft.htform.Widget

ACTIONCSSCLASS, akprompt, attrs, CONTEXTATTRIBUTESSUFFIX, cssClass, DANGEROUSCSSCLASS, debug, DEFAULTTOKEN, dflt, form, generateAs, GENERATEASHTML, GENERATEASXFORM, GENERATEASXML, help, HELPTOKEN, immutable, ISIMMUTABLETOKEN, ISMANDATORYTOKEN, mandatory, MANDATORYCSSCLASS, maxVisibleSize, name, NAMETOKEN, OPTIONALCSSCLASS, PREVIOUSVALUESUFFIX, prompt, PROMPTTOKEN, size, SIZETOKEN, type, TYPETOKEN

Fields inherited from class uk.co.weft.domutil.NodeGeneratorImpl

namespaceURI

Fields inherited from class uk.co.weft.htform.ResourceConsumerImpl

resourceBundleName

Fields inherited from interface uk.co.weft.domutil.NodeGenerator

NAMESPACEURIMAGICTOKEN

Fields inherited from interface uk.co.weft.htform.ResourceConsumer

RESOURCEBUNDLEMAGICTOKEN

Constructor Summary

ActionWidget()
set up my input type

ActionWidget(java.lang.String myname)
I would like a name

ActionWidget(java.lang.String name, java.lang.String prompt)
name and prompt is better

ActionWidget(java.lang.String name, java.lang.String prompt, java.lang.String help)
name, prompt and helptext is better still.

Method Summary

protected void	execute(Context c) the default execute method does nothing whatever.
Node	generateInnerHTML(Document doc, Context context) Generate a node representing the XHTML 1.0 representation of this widget.
protected void	layout(Context context, java.lang.String inputType, int tabIndex) layout *just* the widget, without prompt, help, or surrounding context.
protected boolean	maybeExecute(Context context, Context whinges) decide whether to claim the right to execute my action in this context; if claiming the right execute the action and return true; otherwise just return false.
protected boolean	validateOK(Context context, Context whinges) Determine whether it is safe to execute in this context.

Methods inherited from class uk.co.weft.htform.Widget

clone, generate, generateAttributes, generateAttributes, generateHTML, generateHTMLPrompt, generateValue, generateXML, getContextAttribute, getCssClass, getHeight, getHelp, getName, getPrompt, getTabPlaces, getType, getWidth, init, layout, layout, layout, layoutAttribute, layoutAttributes, layoutValue, makeReady, maybeLayout, maybeLayout, onloadRequest, onloadRequest, postProcess, preProcess, scriptRequest, scriptRequest, setAttribute, setContextAttribute, setCssClass, setDebug, setDefault, setHelp, setImmutable, setMandatory, setMandatory, setName, setPrompt, setSize, setType

Methods inherited from class uk.co.weft.domutil.NodeGeneratorImpl

getNamespaceURI, setNamespaceURI

Methods inherited from class uk.co.weft.htform.ResourceConsumerImpl

getContextOrResource, getResource, getResourceOrContext, getResourceString, grs, grs

Methods inherited from class java.lang.Object

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

Methods inherited from interface uk.co.weft.domutil.NodeGenerator

generate, getName, getNamespaceURI, init, setDebug

Field Detail

commandToken

public static final java.lang.String commandToken

See Also:

Constant Field Values

Constructor Detail

ActionWidget

public ActionWidget()

set up my input type

ActionWidget

public ActionWidget(java.lang.String myname)

I would like a name

ActionWidget

public ActionWidget(java.lang.String name,
                    java.lang.String prompt)

name and prompt is better

ActionWidget

public ActionWidget(java.lang.String name,
                    java.lang.String prompt,
                    java.lang.String help)

name, prompt and helptext is better still.

Method Detail

layout

protected void layout(Context context,
                      java.lang.String inputType,
                      int tabIndex)
               throws DataFormatException,
                      javax.servlet.ServletException,
                      java.io.IOException

layout *just* the widget, without prompt, help, or surrounding context. Note that the input name of an action widget is always 'action', and what was given to us as it's name appears as it's value.

Overrides:

layout in class Widget

Parameters:

context - the service context

inputType - the input type to lay me out as

tabIndex - the tabindex to use, ot the tab index of my first sub-widget if I have more than one

Throws:

javax.servlet.ServletException - I don't, but things which specialise me may

java.io.IOException - if can't write to the output stream

DataFormatException

maybeExecute

protected boolean maybeExecute(Context context,
                               Context whinges)
                        throws java.lang.Exception

decide whether to claim the right to execute my action in this context; if claiming the right execute the action and return true; otherwise just return false.

Parameters:

context - the context containing all the values entered by the user

whinges - a context containing exceptions thrown while pre-processing widgets

Throws:

java.lang.Exception

validateOK

protected boolean validateOK(Context context,
                             Context whinges)

Determine whether it is safe to execute in this context. A method of its own to allow for specialisation. Default behaviour: always return true (i.e. ignore whinges).

Parameters:

context - the context containing all the values entered by the user

whinges - a context containing exceptions thrown while pre-processing widgets

Returns:

true if safe to execute, else false.

execute

protected void execute(Context c)
                throws java.lang.Exception

the default execute method does nothing whatever. You *must* specialise this in order to do anything useful.

Parameters:

c - the context of this request

Throws:

doesn't - actually throw any exception but things which specialise it may want to.

java.lang.Exception

generateInnerHTML

public Node generateInnerHTML(Document doc,
                              Context context)
                       throws GenerationException

Generate a node representing the XHTML 1.0 representation of this widget.

Overrides:

generateInnerHTML in class Widget

Parameters:

doc - the document within which I am to be created

context - the context in which I am to be created.

Returns:

an element representing either the INPUT element itself or a SPAN element containing the INPUT element and any other functionally supporting stuff (SCRIPTs, other INPUTs, APPLETs etc

Throws:

GenerationException

See Also:

Widget.layout(Context), Widget.generateHTML(Document, Context)