uk.ac.ed.epcc.webapp.forms.stateful

Class FormState

java.lang.Object

uk.ac.ed.epcc.webapp.AbstractContexed

uk.ac.ed.epcc.webapp.forms.stateful.FormState

All Implemented Interfaces:

Contexed

public class FormState
extends AbstractContexed

Form state held in the session. This is to implement multi-stage forms built using a single build method. The normal idiom is that the multi-stage form is a single form where sets of inputs are added in stages (being validated and locked on each stage transition) allowing the values chosen in early stages to be used to customise the form contents in later stages.

See Also:

RedisplayResult

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	FormState.NextAction
class	FormState.ResetAction

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	NEXT_ACTION
static java.lang.String	RESET_ACTION

Fields inherited from class uk.ac.ed.epcc.webapp.AbstractContexed

conn

Constructor Summary

Constructors

Constructor and Description
FormState(AppContext conn, java.lang.String name, FormResult self)

Method Summary

Modifier and Type	Method and Description
void	clear() Delete all cached state under this name.
boolean	poll(Form f) poll the cached state for the contents of a partially build form.

Methods inherited from class uk.ac.ed.epcc.webapp.AbstractContexed

getContext, getLogger, resetLogger

Methods inherited from class java.lang.Object

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

Field Detail

NEXT_ACTION

public static final java.lang.String NEXT_ACTION

See Also:

Constant Field Values

RESET_ACTION

public static final java.lang.String RESET_ACTION

See Also:

Constant Field Values

Constructor Detail

FormState

public FormState(AppContext conn,
                 java.lang.String name,
                 FormResult self)

Parameters:

conn -

Method Detail

poll

public boolean poll(Form f)
             throws TransitionException

poll the cached state for the contents of a partially build form. If all the form inputs have values cached in the form state then the form contents will be updated to match.

If the form validates in the new state:

• The existing inputs are all locked
• A reset action is added to clear the cached state
• The method returns true.

If the form fails to validate an exception is thrown. It should validate if the form is built consistently as the cached values will have come from a previous iteration.

If the cached values are not found:

• A next action is added that will update the cached state. Note that the reset action may also be present if this is not the first stage.
• The method returns false to indicate to the form building method that form building should stop at this point.

Parameters:

f - Form being built

Returns:

true/false if form building should continue.

Throws:

TransitionException

clear

public void clear()

Delete all cached state under this name. Normally this should be called as part of the final form action to reset the multi-stage form. Otherwise it will return to the last stage if re-visited.