org.apache.wicket.markup.html.form
Class FormComponent<T>

java.lang.Object
  org.apache.wicket.Component
      org.apache.wicket.MarkupContainer
          org.apache.wicket.markup.html.WebMarkupContainer
              org.apache.wicket.markup.html.form.LabeledWebMarkupContainer
                  org.apache.wicket.markup.html.form.FormComponent<T>

Type Parameters:

T - The model object type

All Implemented Interfaces:

java.io.Serializable, java.lang.Iterable<Component>, IEventSink, IEventSource, IClusterable, IConverterLocator, IFormModelUpdateListener, IFormVisitorParticipant, ILabelProvider<java.lang.String>, IHeaderContributor, IRequestableComponent, IHierarchical<Component>

Direct Known Subclasses:

AbstractChoice, AbstractOptions, AbstractTextComponent, Button, CheckBox, CheckGroup, FileUploadField, FormComponentPanel, RadioGroup, Select

public abstract class FormComponent<T>
extends LabeledWebMarkupContainer
implements IFormVisitorParticipant, IFormModelUpdateListener

An HTML form component knows how to validate itself. Validators that implement IValidator can be added to the component. They will be evaluated in the order they were added and the first Validator that returns an error message determines the error message returned by the component.

FormComponents are not versioned by default. If you need versioning for your FormComponents, you will need to call Form.setVersioned(true), which will set versioning on for the form and all form component children.

If this component is required and that fails, the error key that is used is the "Required"; if the type conversion fails, it will use the key "IConverter" if the conversion failed in a converter, or "ConversionError" if type was explicitly specified via setType(Class) or a IPropertyReflectionAwareModel was used. Notice that both "IConverter" and "ConversionError" have a more specific variant of "key.classname" where classname is the type that we failed to convert to. Classname is not full qualified, so only the actual name of the class is used. Property expressions that can be used in error messages are:

• ${input}: the input the user did give
• ${name}: the name of the component that failed
• ${label}: the label of the component

Author:

Jonathan Locke, Eelco Hillenius, Johan Compagner, Igor Vaynberg (ivaynberg)

See Also:

Serialized Form

Field Summary

protected static short	FLAG_CONVERT_EMPTY_INPUT_STRING_TO_NULL Make empty strings null values boolean.
static java.lang.String	VALUE_SEPARATOR The value separator

Fields inherited from class org.apache.wicket.Component

ENABLE, FLAG_INITIALIZED, FLAG_REMOVING_FROM_HIERARCHY, FLAG_RESERVED1, FLAG_RESERVED2, FLAG_RESERVED3, FLAG_RESERVED4, FLAG_RESERVED5, FLAG_RESERVED8, PARENT_PATH, PATH_SEPARATOR, RENDER

Constructor Summary

FormComponent(java.lang.String id)

FormComponent(java.lang.String id, IModel<T> model)

Method Summary

FormComponent<T>	add(IValidator<? super T>... validators) Adds a validator to this form component.
FormComponent<T>	add(IValidator<? super T> validator) Adds a validator to this form component
boolean	checkRequired() Checks if the form component's 'required' requirement is met by first checking isRequired() to see if it has to check for requirement.
void	clearInput() Clears the user input.
protected void	convertInput() Converts and validates the conversion of the raw input string into the object specified by getType() and records any errors.
protected T	convertValue(java.lang.String[] value) Subclasses should overwrite this if the conversion is not done through the type field and the IConverter.
void	error(IValidationError error) Reports a validation error against this form component.
T	getConvertedInput() Gets the converted input.
java.lang.String	getDefaultLabel() Gets the string the component would use as a label when one was requested but no label model was set via LabeledWebMarkupContainer.getLabel().
java.lang.String	getDefaultLabel(java.lang.String defaultValue) Gets the string the component would use as a label when one was requested but no label model was set via LabeledWebMarkupContainer.getLabel().
Form<?>	getForm()
java.lang.String	getInput() Gets the request parameter for this component as a string.
java.lang.String[]	getInputAsArray() Gets the request parameters for this component as strings.
java.lang.String	getInputName() Gets the string to be used for the name attribute of the form element.
IModel<T>	getModel() Gets model
T	getModelObject() Gets model object
protected java.lang.String	getModelValue()
java.lang.String	getRawInput() Use hasRawInput() to check if this component has raw input because null can mean 2 things: It doesn't have rawinput or the rawinput is really null.
java.lang.Class<T>	getType()
java.lang.String	getValidatorKeyPrefix()
java.util.List<IValidator<? super T>>	getValidators() Gets an unmodifiable list of validators for this FormComponent.
java.lang.String	getValue() Gets current value for a form component, which can be either input data entered by the user, or the component's model object if no input was provided.
boolean	hasRawInput() Returns whether this component has raw input.
protected int	inputAsInt() Gets the request parameter for this component as an int.
protected int	inputAsInt(int defaultValue) Gets the request parameter for this component as an int, using the given default in case no corresponding request parameter was found.
protected int[]	inputAsIntArray() Gets the request parameters for this component as ints.
void	inputChanged() Used by Form to tell the FormComponent that a new user input is available
protected void	internalOnModelChanged() THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.
void	invalid() Indicate that validation of this form component failed.
boolean	isInputNullable() Gets whether this component's input can be null.
boolean	isMultiPart()
boolean	isRequired()
boolean	isValid() Gets whether this component is 'valid'.
IValidatable<T>	newValidatable() Creates an IValidatable that can be used to validate this form component.
protected void	onComponentTag(ComponentTag tag) Processes the component tag.
protected void	onDetach() Sets the temporary converted input value to null.
protected void	onDisabled(ComponentTag tag) Called by onComponentTag(ComponentTag) when the component is disabled.
protected void	onInvalid() Handle invalidation
protected void	onValid() Handle validation
boolean	processChildren() Should children be traversed during visiting or should only the siblings be processed.
void	processInput() This method will retrieve the request parameter, validate it, and if valid update the model.
FormComponent<T>	remove(IValidator<? super T> validator) Removes a validator from the form component.
void	setConvertedInput(T convertedInput) Sets the converted input.
FormComponent<T>	setLabel(IModel<java.lang.String> labelModel) The value will be made available to the validator property by means of ${label}.
void	setModel(IModel<T> model) Sets model
void	setModelObject(T object) Sets model object
void	setModelValue(java.lang.String[] value) Sets the value for a form component.
FormComponent<T>	setRequired(boolean required) Sets the required flag
FormComponent<T>	setType(java.lang.Class<?> type) Sets the type that will be used when updating the model for this component.
protected boolean	shouldTrimInput() Determines whether or not this component should trim its input prior to processing it.
protected java.lang.String	trim(java.lang.String string) Trims the input according to shouldTrimInput()
protected static <S> void	updateCollectionModel(FormComponent<java.util.Collection<S>> formComponent) Update the model of a FormComponent containing a Collection.
void	updateModel() Updates this components model from the request, it expects that the object is already converted through the convertInput() call that is called by the validate() method when a form is being processed.
void	valid() Called to indicate that the user input is valid.
void	validate() Performs full validation of the form component, which consists of calling validateRequired(), convertInput(), and validateValidators().
protected void	validateRequired() Checks if the raw input value is not null if this component is required.
protected void	validateValidators() Validates this component using the component's validators.
static <R> R	visitComponentsPostOrder(Component component, IVisitor<Component,R> visitor) Visits any form components inside component if it is a container, or component itself if it is itself a form component
static <R> R	visitFormComponentsPostOrder(Component component, IVisitor<? extends FormComponent<?>,R> visitor) Visits any form components inside component if it is a container, or component itself if it is itself a form component

Methods inherited from class org.apache.wicket.markup.html.form.LabeledWebMarkupContainer

getLabel, setLabelInternal

Methods inherited from class org.apache.wicket.markup.html.WebMarkupContainer

getWebPage, getWebRequest

Methods inherited from class org.apache.wicket.MarkupContainer

add, addOrReplace, autoAdd, contains, get, get, getAssociatedMarkup, getAssociatedMarkupStream, getMarkup, getMarkupType, hasAssociatedMarkup, internalAdd, internalInitialize, iterator, iterator, onAfterRenderChildren, onComponentTagBody, onMarkupAttached, onRender, remove, remove, removeAll, renderAll, renderAssociatedMarkup, renderNext, replace, setDefaultModel, size, swap, toString, toString, visitChildren, visitChildren, visitChildren, visitChildren

Methods inherited from class org.apache.wicket.Component

add, addStateChange, afterRender, beforeRender, canCallListenerInterface, checkComponentTag, checkComponentTagAttribute, checkHierarchyChange, configure, continueToOriginalDestination, debug, detach, detachModel, detachModels, determineVisibility, error, exceptionMessage, fatal, findMarkupStream, findPage, findParent, findParentWithAssociatedMarkup, getAjaxRegionMarkupId, getApplication, getBehaviorById, getBehaviorId, getBehaviors, getBehaviors, getClassRelativePath, getConverter, getDefaultModel, getDefaultModelObject, getDefaultModelObjectAsString, getDefaultModelObjectAsString, getEscapeModelStrings, getFeedbackMessage, getFeedbackMessages, getFlag, getId, getInnermostModel, getInnermostModel, getLocale, getLocalizer, getMarkup, getMarkupAttributes, getMarkupId, getMarkupId, getMarkupIdFromMarkup, getMarkupIdImpl, getMarkupSourcingStrategy, getMetaData, getModelComparator, getOutputMarkupId, getOutputMarkupPlaceholderTag, getPage, getPageRelativePath, getParent, getPath, getRenderBodyOnly, getRequest, getRequestCycle, getRequestFlag, getResponse, getSession, getSizeInBytes, getStatelessHint, getString, getString, getString, getStyle, getVariation, hasBeenRendered, hasErrorMessage, hasFeedbackMessage, info, initModel, internalPrepareForRender, internalRenderComponent, isActionAuthorized, isAuto, isBehaviorAccepted, isEnableAllowed, isEnabled, isEnabledInHierarchy, isIgnoreAttributeModifier, isRenderAllowed, isStateless, isVersioned, isVisibilityAllowed, isVisible, isVisibleInHierarchy, locateMarkupStream, markRendering, modelChanged, modelChanging, newMarkupSourcingStrategy, onAfterRender, onBeforeRender, onConfigure, onEvent, onInitialize, onModelChanged, onModelChanging, onRemove, prepareForRender, redirectToInterceptPage, remove, remove, render, renderComponentTag, rendered, renderHead, renderHead, renderHead, renderPlaceholderTag, replaceComponentTagBody, replaceWith, sameInnermostModel, sameInnermostModel, send, setAuto, setDefaultModelObject, setEnabled, setEscapeModelStrings, setFlag, setIgnoreAttributeModifier, setMarkup, setMarkupId, setMarkupIdImpl, setMetaData, setOutputMarkupId, setOutputMarkupPlaceholderTag, setParent, setRenderBodyOnly, setRequestFlag, setResponsePage, setResponsePage, setResponsePage, setVersioned, setVisibilityAllowed, setVisible, success, urlFor, urlFor, urlFor, urlFor, urlFor, visitParents, warn, wrap

Methods inherited from class java.lang.Object

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

Field Detail

VALUE_SEPARATOR

public static final java.lang.String VALUE_SEPARATOR

The value separator

See Also:

Constant Field Values

FLAG_CONVERT_EMPTY_INPUT_STRING_TO_NULL

protected static final short FLAG_CONVERT_EMPTY_INPUT_STRING_TO_NULL

Make empty strings null values boolean. Used by AbstractTextComponent subclass.

See Also:

Constant Field Values

Constructor Detail

FormComponent

public FormComponent(java.lang.String id)

See Also:

Component.Component(String)

FormComponent

public FormComponent(java.lang.String id,
                     IModel<T> model)

Parameters:

id -

model -

See Also:

Component.Component(String, IModel)

Method Detail

visitFormComponentsPostOrder

public static final <R> R visitFormComponentsPostOrder(Component component,
                                                       IVisitor<? extends FormComponent<?>,R> visitor)

Visits any form components inside component if it is a container, or component itself if it is itself a form component

Type Parameters:

R - the type of the visitor's result

Parameters:

component - starting point of the traversal

visitor - The visitor to call

Returns:

the visitor's result

visitComponentsPostOrder

public static final <R> R visitComponentsPostOrder(Component component,
                                                   IVisitor<Component,R> visitor)

Visits any form components inside component if it is a container, or component itself if it is itself a form component

Type Parameters:

R - the type of the visitor's result

Parameters:

component - starting point of the traversal

visitor - The visitor to call

Returns:

the visitor's result

getDefaultLabel

public final java.lang.String getDefaultLabel()

Gets the string the component would use as a label when one was requested but no label model was set via LabeledWebMarkupContainer.getLabel(). The value of this string is usually set in a property file; if the value is not set the default value equivalent to component id will be returned.

Returns:

localized label

getDefaultLabel

public final java.lang.String getDefaultLabel(java.lang.String defaultValue)

Gets the string the component would use as a label when one was requested but no label model was set via LabeledWebMarkupContainer.getLabel(). The value of this string is usually set in a property file; if the value is not set the defaultValue will be returned.

Parameters:

defaultValue -

Returns:

localized label

add

public final FormComponent<T> add(IValidator<? super T> validator)

Adds a validator to this form component

Parameters:

validator - validator to be added

Returns:

this for chaining

Throws:

java.lang.IllegalArgumentException - if validator is null

See Also:

IValidator, IValidatorAddListener

remove

public final FormComponent<T> remove(IValidator<? super T> validator)

Removes a validator from the form component.

Parameters:

validator - validator

Returns:

form component for chaining

Throws:

java.lang.IllegalArgumentException - if validator is null or not found

See Also:

IValidator, add(IValidator)

add

public final FormComponent<T> add(IValidator<? super T>... validators)

Adds a validator to this form component.

Parameters:

validators - The validator(s) to be added

Returns:

This

Throws:

java.lang.IllegalArgumentException - if validator is null

See Also:

IValidator, IValidatorAddListener

checkRequired

public boolean checkRequired()

Checks if the form component's 'required' requirement is met by first checking isRequired() to see if it has to check for requirement. If that is true then by default it checks if the input is null or an empty String Strings.isEmpty(CharSequence)

Subclasses that overwrite this method should also call isRequired() first.

Returns:

true if the 'required' requirement is met, false otherwise

See Also:

Strings.isEmpty(CharSequence), isInputNullable()

clearInput

public final void clearInput()

Clears the user input.

error

public void error(IValidationError error)

Reports a validation error against this form component. The actual error is reported by creating a ValidationErrorFeedback object that holds both the validation error and the generated error message - so a custom feedback panel can have access to both.

Parameters:

error - validation error

getConvertedInput

public final T getConvertedInput()

Gets the converted input. The converted input is set earlier though the implementation of convertInput(). FormComponentPanel often access this method when constructing their converted input value which is often the combination of converted values of the embedded FormComponents To access the model object resulted by the full form processing, use getModelObject() instead, that is an generified version of Component.getDefaultModelObject()

Returns:

value of input possibly converted into an appropriate type

setConvertedInput

public final void setConvertedInput(T convertedInput)

Sets the converted input. This method is typically not called by clients, unless they override convertInput(), in which case they should call this method to update the input for this component instance.

Parameters:

convertedInput - the converted input

getForm

public Form<?> getForm()

Returns:

The parent form for this form component

getInput

public java.lang.String getInput()

Gets the request parameter for this component as a string.

Returns:

The value in the request for this component

getInputAsArray

public java.lang.String[] getInputAsArray()

Gets the request parameters for this component as strings.

Returns:

The values in the request for this component

getInputName

public java.lang.String getInputName()

Gets the string to be used for the name attribute of the form element. Generated using the path from the form to the component, excluding the form itself. Override it if you want even a smaller name. E.g. if you know for sure that the id is unique within a form.

Returns:

The string to use as the form element's name attribute

getRawInput

public final java.lang.String getRawInput()

Use hasRawInput() to check if this component has raw input because null can mean 2 things: It doesn't have rawinput or the rawinput is really null.

Returns:

The raw form input that is stored for this formcomponent

getType

public final java.lang.Class<T> getType()

Returns:

the type to use when updating the model for this form component

getValidatorKeyPrefix

public java.lang.String getValidatorKeyPrefix()

Returns:

prefix used when constructing validator key messages

See Also:

Form.getValidatorKeyPrefix()

getValidators

public final java.util.List<IValidator<? super T>> getValidators()

Gets an unmodifiable list of validators for this FormComponent.

Returns:

List of validators

getValue

public final java.lang.String getValue()

Gets current value for a form component, which can be either input data entered by the user, or the component's model object if no input was provided.

Returns:

The value

hasRawInput

public final boolean hasRawInput()

Returns whether this component has raw input. Raw input is unconverted input straight from the client.

Returns:

boolean whether this component has raw input.

inputChanged

public final void inputChanged()

Used by Form to tell the FormComponent that a new user input is available

invalid

public final void invalid()

Indicate that validation of this form component failed.

isInputNullable

public boolean isInputNullable()

Gets whether this component's input can be null. By default, components that do not get input will have null values passed in for input. However, component TextField is an example (possibly the only one) that never gets a null passed in, even if the field is left empty UNLESS it had attribute disabled="disabled" set.

Returns:

True if this component's input can be null. Returns true by default.

isMultiPart

public boolean isMultiPart()

Returns:

True if this component encodes data in a multipart form submit

isRequired

public boolean isRequired()

Returns:

whether or not this component's value is required

isValid

public final boolean isValid()

Gets whether this component is 'valid'. Valid in this context means that no validation errors were reported the last time the form component was processed. This variable not only is convenient for 'business' use, but is also necessary as we don't want the form component models updated with invalid input.

Returns:

valid whether this component is 'valid'

processChildren

public boolean processChildren()

Description copied from interface: IFormVisitorParticipant

Should children be traversed during visiting or should only the siblings be processed.

Specified by:

processChildren in interface IFormVisitorParticipant

Returns:

true if children should be traversed during form processing; false if only the siblings should be processed.

See Also:

IFormVisitorParticipant.processChildren()

processInput

public final void processInput()

This method will retrieve the request parameter, validate it, and if valid update the model. These are the same steps as would be performed by the form. This is useful when a formcomponent is used outside a form.

setLabel

public FormComponent<T> setLabel(IModel<java.lang.String> labelModel)

The value will be made available to the validator property by means of ${label}. It does not have any specific meaning to FormComponent itself.

Parameters:

labelModel -

Returns:

this for chaining

setModelValue

public void setModelValue(java.lang.String[] value)

Sets the value for a form component.

Parameters:

value - The value

setRequired

public final FormComponent<T> setRequired(boolean required)

Sets the required flag

Parameters:

required -

Returns:

this for chaining

setType

public FormComponent<T> setType(java.lang.Class<?> type)

Sets the type that will be used when updating the model for this component. If no type is specified String type is assumed.

Parameters:

type -

Returns:

this for chaining

updateModel

public void updateModel()

Updates this components model from the request, it expects that the object is already converted through the convertInput() call that is called by the validate() method when a form is being processed. By default it just does this:

 setModelObject(getConvertedInput());
 

DO NOT CALL THIS METHOD DIRECTLY UNLESS YOU ARE SURE WHAT YOU ARE DOING. USUALLY UPDATING YOUR MODEL IS HANDLED BY THE FORM, NOT DIRECTLY BY YOU.

Specified by:

updateModel in interface IFormModelUpdateListener

valid

public final void valid()

Called to indicate that the user input is valid.

validate

public void validate()

Performs full validation of the form component, which consists of calling validateRequired(), convertInput(), and validateValidators(). This method should only be used if the form component needs to be fully validated outside the form process.

convertInput

protected void convertInput()

Converts and validates the conversion of the raw input string into the object specified by getType() and records any errors. Converted value is available through getConvertedInput().

Usually the user should do custom conversions by specifying an IConverter by registering it with the application by overriding Application.getConverterLocator(), or at the component level by overriding Component.getConverter(Class) .

See Also:

IConverterLocator, Application.newConverterLocator()

convertValue

protected T convertValue(java.lang.String[] value)
                  throws ConversionException

Subclasses should overwrite this if the conversion is not done through the type field and the IConverter. WARNING: this method may be removed in future versions. If conversion fails then a ConversionException should be thrown

Parameters:

value - The value can be the getInput() or through a cookie

Returns:

The converted value. default returns just the given value

Throws:

ConversionException - If input can't be converted

getModelValue

protected java.lang.String getModelValue()

Returns:

Value to return when model value is needed

inputAsInt

protected final int inputAsInt()

Gets the request parameter for this component as an int.

Returns:

The value in the request for this component

inputAsInt

protected final int inputAsInt(int defaultValue)

Gets the request parameter for this component as an int, using the given default in case no corresponding request parameter was found.

Parameters:

defaultValue - Default value to return if request does not have an integer for this component

Returns:

The value in the request for this component

inputAsIntArray

protected final int[] inputAsIntArray()

Gets the request parameters for this component as ints.

Returns:

The values in the request for this component

internalOnModelChanged

protected void internalOnModelChanged()

Description copied from class: Component

THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT CALL OR OVERRIDE.

Called anytime a model is changed via setModel or setModelObject.

Overrides:

internalOnModelChanged in class Component

See Also:

Component.internalOnModelChanged()

onComponentTag

protected void onComponentTag(ComponentTag tag)

Processes the component tag.

Overrides:

onComponentTag in class Component

Parameters:

tag - Tag to modify

See Also:

Component.onComponentTag(ComponentTag)

onDetach

protected void onDetach()

Sets the temporary converted input value to null.

Overrides:

onDetach in class LabeledWebMarkupContainer

See Also:

Component.onDetach()

onDisabled

protected void onDisabled(ComponentTag tag)

Called by onComponentTag(ComponentTag) when the component is disabled. By default, this method will add a disabled="disabled" attribute to the tag. Components may override this method to tweak the tag as they think is fit.

Parameters:

tag - the tag that is being rendered

onInvalid

protected void onInvalid()

Handle invalidation

onValid

protected void onValid()

Handle validation

shouldTrimInput

protected boolean shouldTrimInput()

Determines whether or not this component should trim its input prior to processing it. The default value is true

Returns:

True if the input should be trimmed.

trim

protected final java.lang.String trim(java.lang.String string)

Trims the input according to shouldTrimInput()

Parameters:

string -

Returns:

trimmed input if shouldTrimInput() returns true, unchanged input otherwise

validateRequired

protected final void validateRequired()

Checks if the raw input value is not null if this component is required.

validateValidators

protected final void validateValidators()

Validates this component using the component's validators.

newValidatable

public final IValidatable<T> newValidatable()

Creates an IValidatable that can be used to validate this form component. This validatable incorporates error key lookups that correspond to this form component. This method is useful when validation needs to happen outside the regular validation workflow but error messages should still be properly reported against the form component.

Returns:

IValidatable for this form component

getModel

public final IModel<T> getModel()

Gets model

Returns:

model

setModel

public final void setModel(IModel<T> model)

Sets model

Parameters:

model -

getModelObject

public final T getModelObject()

Gets model object

Returns:

model object

setModelObject

public final void setModelObject(T object)

Sets model object

Parameters:

object -

updateCollectionModel

protected static <S> void updateCollectionModel(FormComponent<java.util.Collection<S>> formComponent)

Update the model of a FormComponent containing a Collection. If the model object does not yet exists, a new ArrayList is filled with the converted input and used as the new model object. Otherwise the existing collection is modified in-place, then IModel.setObject(Object) is called with the same instance: it allows the Model to be notified of changes even when Model.getObject() returns a different Collection at every invocation.

Type Parameters:

S - collection type

Parameters:

formComponent - the form component to update

Throws:

java.lang.UnsupportedOperationException - if the existing model object Collection cannot be modified

See Also:

updateModel()