uk.ac.ed.epcc.webapp.forms.inputs

Class ErrorInput<T>

java.lang.Object

uk.ac.ed.epcc.webapp.forms.inputs.ErrorInput<T>

Type Parameters:

T - type of input

All Implemented Interfaces:

Input<T>, UnmodifiableInput

public class ErrorInput<T>
extends java.lang.Object
implements UnmodifiableInput, Input<T>

An ErrorInput is an unmodifiable input that never validates. It can used to indicate that no valid selections are possible for the user or that an error occurred while generating the form.

Constructor Summary

Constructors

Constructor and Description
ErrorInput(java.lang.String text)

Method Summary

Modifier and Type	Method and Description
<R> R	accept(InputVisitor<R> vis)
void	addValidator(FieldValidator<T> val) Add a FieldValidator to this input
T	convert(java.lang.Object v) Perform any supported type conversions to to generate a value of the target type
java.lang.String	getKey() get the unique key for this selector
java.lang.String	getLabel() generate the text to be presented to the user
java.lang.String	getPrettyString(T value) Convert a value into a user friendly string.
java.lang.String	getString(T value) convert a value of the correct type for this input into a String.
T	getValue() get the current value of the Object created by this selector.
boolean	isEmpty() Is the input empty.
void	removeValidator(FieldValidator<T> val) Remove a FieldValidator from this input
void	setKey(java.lang.String key) Set the key used by this Selector
T	setValue(T v) set the value of this selector.
void	validate() Check the validity of the current state of the Object.

Methods inherited from class java.lang.Object

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

Constructor Detail

ErrorInput

public ErrorInput(java.lang.String text)

Method Detail

getLabel

public java.lang.String getLabel()

Description copied from interface: UnmodifiableInput

generate the text to be presented to the user

Specified by:

getLabel in interface UnmodifiableInput

Returns:

String

convert

public T convert(java.lang.Object v)
          throws TypeError

Description copied from interface: Input

Perform any supported type conversions to to generate a value of the target type

Specified by:

convert in interface Input<T>

Parameters:

v - Object input

Returns:

target type

Throws:

TypeError

getKey

public java.lang.String getKey()

Description copied from interface: Input

get the unique key for this selector

Specified by:

getKey in interface Input<T>

Returns:

Object key for this Selector

getPrettyString

public java.lang.String getPrettyString(T value)

Description copied from interface: Input

Convert a value into a user friendly string. This usually defaults to the same as getString but can be overridden to produce nicer output

Specified by:

getPrettyString in interface Input<T>

Returns:

String

See Also:

ListInput

getString

public java.lang.String getString(T value)

Description copied from interface: Input

convert a value of the correct type for this input into a String. If this input is a parseInput this must be compatible with the way the input is parsed. To make testing easier equivalent values should convert to the same canonical form.

Specified by:

getString in interface Input<T>

Returns:

String or null if value is null

See Also:

ParseInput

getValue

public T getValue()

Description copied from interface: Input

get the current value of the Object created by this selector.

Specified by:

getValue in interface Input<T>

Returns:

Object value of this selector

setKey

public void setKey(java.lang.String key)

Description copied from interface: Input

Set the key used by this Selector

Specified by:

setKey in interface Input<T>

setValue

public T setValue(T v)
           throws TypeError

Description copied from interface: Input

set the value of this selector. This is either called by the Form to specify a default value or by the edit methods in the sub-class implementation.

Specified by:

setValue in interface Input<T>

Returns:

previous value Object

Throws:

TypeError

isEmpty

public boolean isEmpty()

Description copied from interface: Input

Is the input empty. empty inputs are reported as errors for non-optional fields. Additional validation is not performed if the input is empty.

Specified by:

isEmpty in interface Input<T>

Returns:

validate

public void validate()
              throws FieldException

Description copied from interface: Input

Check the validity of the current state of the Object.

Specified by:

validate in interface Input<T>

Throws:

FieldException

accept

public <R> R accept(InputVisitor<R> vis)
             throws java.lang.Exception

Specified by:

accept in interface Input<T>

Throws:

java.lang.Exception

addValidator

public void addValidator(FieldValidator<T> val)

Description copied from interface: Input

Add a FieldValidator to this input

Specified by:

addValidator in interface Input<T>

removeValidator

public void removeValidator(FieldValidator<T> val)

Description copied from interface: Input

Remove a FieldValidator from this input

Specified by:

removeValidator in interface Input<T>