org.apache.tapestry.valid
Class ValidField

java.lang.Object
  org.apache.tapestry.spec.BaseLocatable
      org.apache.tapestry.AbstractComponent
          org.apache.tapestry.form.AbstractFormComponent
              org.apache.tapestry.form.AbstractTextField
                  org.apache.tapestry.valid.ValidField

All Implemented Interfaces:

IFormComponent, IComponent, ILocatable, ILocationHolder, IRender

Direct Known Subclasses:

DateField, NumericField, ValidatingTextField

public abstract class ValidField
extends AbstractTextField
implements IFormComponent

A Form component that creates a text field that allows for validation of user input and conversion between string and object values. [Component Reference]

A ValidatingTextField uses an IValidationDelegate to track errors and an IValidator to convert between strings and objects (as well as perform validations). The validation delegate is shared by all validating text fields in a form, the validator may be shared my multiple elements as desired.

Version:

$Id: ValidField.java 243791 2004-02-19 17:38:13Z hlship $

Author:

Howard Lewis Ship

Constructor Summary

ValidField()

Method Summary

protected void	addSelect(IRequestCycle cycle) Creates JavaScript to set the cursor on the first required or error field encountered while rendering.
protected void	beforeCloseTag(IMarkupWriter writer, IRequestCycle cycle) Invokes IValidationDelegate.writeAttributes(IMarkupWriter,IRequestCycle, IFormComponent,IValidator).
abstract String	getDisplayName() Implemented in some subclasses to provide a display name (suitable for presentation to the user as a label or error message).
abstract IValidator	getValidator()
abstract Object	getValue()
protected String	readValue() Invoked by AbstractComponent.render(IMarkupWriter writer, IRequestCycle cycle) when rendering a response.
protected void	renderComponent(IMarkupWriter writer, IRequestCycle cycle) Renders the component, which involves the delegate.
abstract void	setValue(Object value)
protected void	updateValue(String value) Invoked by AbstractComponent.render(IMarkupWriter writer, IRequestCycle cycle) when a value is obtained from the HttpServletRequest.

Methods inherited from class org.apache.tapestry.form.AbstractTextField

isDisabled, isHidden

Methods inherited from class org.apache.tapestry.form.AbstractFormComponent

getForm, getForm, getName, setForm, setName

Methods inherited from class org.apache.tapestry.AbstractComponent

addAsset, addBody, addComponent, cleanupAfterRender, finishLoad, finishLoad, fireObservedChange, fireObservedChange, fireObservedChange, fireObservedChange, fireObservedChange, fireObservedChange, fireObservedChange, fireObservedChange, fireObservedChange, format, format, format, format, formatString, formatString, formatString, formatString, generateAttributes, getAsset, getAssets, getBeans, getBinding, getBindingNames, getBindings, getBody, getBodyCount, getChangeObserver, getComponent, getComponents, getContainer, getExtendedId, getId, getIdPath, getListeners, getMessage, getMessages, getNamespace, getPage, getProperty, getSpecification, getString, pageEndRender, prepareForRender, render, renderBody, renderInformalParameters, setBinding, setContainer, setId, setNamespace, setPage, setProperty, setSpecification, toString

Methods inherited from class org.apache.tapestry.spec.BaseLocatable

getLocation, setLocation

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.tapestry.form.IFormComponent

getForm, getName, isDisabled, setName

Methods inherited from interface org.apache.tapestry.IComponent

addAsset, addBody, addComponent, finishLoad, getAsset, getAssets, getBinding, getBindingNames, getBindings, getComponent, getComponents, getContainer, getExtendedId, getId, getIdPath, getMessage, getMessages, getNamespace, getPage, getProperty, getSpecification, getString, renderBody, setBinding, setContainer, setId, setNamespace, setPage, setProperty, setSpecification

Methods inherited from interface org.apache.tapestry.IRender

render

Methods inherited from interface org.apache.tapestry.ILocationHolder

setLocation

Methods inherited from interface org.apache.tapestry.ILocatable

getLocation

Constructor Detail

ValidField

public ValidField()

Method Detail

getValue

public abstract Object getValue()

setValue

public abstract void setValue(Object value)

getDisplayName

public abstract String getDisplayName()

Description copied from class: AbstractFormComponent

Implemented in some subclasses to provide a display name (suitable for presentation to the user as a label or error message). This implementation return null.

Specified by:

getDisplayName in interface IFormComponent

Overrides:

getDisplayName in class AbstractFormComponent

renderComponent

protected void renderComponent(IMarkupWriter writer,
                               IRequestCycle cycle)

Renders the component, which involves the delegate.

During a render, the first field rendered that is either in error, or required but null gets special treatment. JavaScript is added to select that field (such that the cursor jumps right to the field when the page loads).

Overrides:

renderComponent in class AbstractTextField

beforeCloseTag

protected void beforeCloseTag(IMarkupWriter writer,
                              IRequestCycle cycle)

Invokes IValidationDelegate.writeAttributes(IMarkupWriter,IRequestCycle, IFormComponent,IValidator).

Overrides:

beforeCloseTag in class AbstractTextField

addSelect

protected void addSelect(IRequestCycle cycle)

Creates JavaScript to set the cursor on the first required or error field encountered while rendering. This only works if the text field is wrapped by a Body component (which is almost always true).

readValue

protected String readValue()

Description copied from class: AbstractTextField

Invoked by AbstractComponent.render(IMarkupWriter writer, IRequestCycle cycle) when rendering a response.

Specified by:

readValue in class AbstractTextField

Returns:

the current value for the field, as a String, or null.

updateValue

protected void updateValue(String value)

Description copied from class: AbstractTextField

Invoked by AbstractComponent.render(IMarkupWriter writer, IRequestCycle cycle) when a value is obtained from the HttpServletRequest.

Specified by:

updateValue in class AbstractTextField

getValidator

public abstract IValidator getValidator()