org.apache.tapestry5.corelib.base

Class AbstractTextField

java.lang.Object

org.apache.tapestry5.corelib.base.AbstractField

org.apache.tapestry5.corelib.base.AbstractTextField

All Implemented Interfaces:

ClientElement, Field

Direct Known Subclasses:

PasswordField, TextArea, TextField

@Events(value={"toClient","validate","parseClient"})
public abstract class AbstractTextField
extends AbstractField

Abstract class for a variety of components that render some variation of a text field. Most of the hooks for user input validation are in this class. In particular, all subclasses support the "toclient" and "parseclient" events. These two events allow the normal Translator (specified by the translate parameter, but often automatically derived by Tapestry) to be augmented. If the component container (i.e., the page) provides an event handler method for the "toclient" event, and that handler returns a non-null string, that will be the string value sent to the client. The context passed to the event handler method is t he current value of the value parameter. Likewise, on a form submit, the "parseclient" event handler method will be passed the string provided by the client, and may provide a non-null value as the parsed value. Returning null allows the normal translator to operate. The event handler may also throw ValidationException.

Component Parameters

Name	Type	Flags	Default	Default Prefix
annotationProvider	org.apache.tapestry5.ioc.AnnotationProvider			prop
	Provider of annotations used for some defaults. Annotation are usually provided in terms of the value parameter (i.e., from the getter and/or setter bound to the value parameter).
clientId	String			literal
	Used to explicitly set the client-side id of the element for this component. Normally this is not bound (or null) and org.apache.tapestry5.services.javascript.JavaScriptSupport#allocateClientId(org.apache.tapestry5.ComponentResources) is used to generate a unique client-id based on the component's id. In some cases, when creating client-side behaviors, it is useful to explicitly set a unique id for an element using this parameter. Certain values, such as "submit", "method", "reset", etc., will cause client-side conflicts and are not allowed; using such will cause a runtime exception.
ensureClientIdUnique	boolean	Since 5.4		prop
	A rarely used option that indicates that the actual client id should start with the clientId parameter (if non-null) but should still pass that Id through org.apache.tapestry5.services.javascript.JavaScriptSupport#allocateClientId(String) to generate the final id. An example of this are the components used inside a org.apache.tapestry5.corelib.components.BeanEditor which will specify a clientId (based on the property name) but still require that it be unique. Defaults to false.
nulls	org.apache.tapestry5.NullFieldStrategy		default	nullfieldstrategy
	Defines how nulls on the server side, or sent from the client side, are treated. The selected strategy may replace the nulls with some other value. The default strategy leaves nulls alone. Another built-in strategy, zero, replaces nulls with the value 0.
translate	org.apache.tapestry5.FieldTranslator	Required, Not Null		translate
	The object which will perform translation between server-side and client-side representations. If not specified, a value will usually be generated based on the type of the value parameter.
validate	org.apache.tapestry5.FieldValidator	Not Null		validate
	The object that will perform input validation (which occurs after translation). The validate binding prefix is generally used to provide this object in a declarative fashion.
value	Object	Required		prop
	The value to be read and updated. This is not necessarily a string, a translator may be provided to convert between client side and server side representations. If not bound, a default binding is made to a property of the container matching the component's id. If no such property exists, then you will see a runtime exception due to the unbound value parameter.

Component Events

Name	Description
parseClient
toClient
validate

Field Summary

Fields inherited from class org.apache.tapestry5.corelib.base.AbstractField

cssClass, decorator, defaultProvider, disabled, environment, fieldValidationSupport, formSupport, javaScriptSupport, label, request, resources, validationTracker

Constructor Summary

Constructors

Constructor and Description
AbstractTextField()

Method Summary

Methods

Modifier and Type	Method and Description
protected String	getWidth() Looks for a Width annotation and, if present, returns its value as a string.
protected boolean	ignoreBlankInput() Should blank input be ignored (after validation)? This will be true for PasswordField.
boolean	isRequired() Returns false; most components do not support declarative validation.
protected void	processSubmission(String controlName) Method implemented by subclasses to actually do the work of processing the submission of the form.
protected abstract void	writeFieldTag(MarkupWriter writer, String value) Invoked from begin(MarkupWriter) to write out the element and attributes (typically, <input>).

Methods inherited from class org.apache.tapestry5.corelib.base.AbstractField

decorateInsideField, getClientId, getControlName, getLabel, isDisabled, putPropertyNameIntoBeanValidationContext, removePropertyNameFromBeanValidationContext, setDecorator, setFormSupport

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractTextField

public AbstractTextField()

Method Detail

writeFieldTag

protected abstract void writeFieldTag(MarkupWriter writer,
                 String value)

Invoked from begin(MarkupWriter) to write out the element and attributes (typically, <input>). The controlName and clientId properties will already have been set or updated. Generally, the subclass will invoke MarkupWriter.element(String, Object[]), and will be responsible for including an AfterRender phase method to invoke MarkupWriter.end().

Parameters:

writer - markup write to send output to

value - the value (either obtained and translated from the value parameter, or obtained from the tracker)

processSubmission

protected void processSubmission(String controlName)

Description copied from class: AbstractField

Method implemented by subclasses to actually do the work of processing the submission of the form. The element's controlName property will already have been set. This method is only invoked if the field is not disabled.

Specified by:

processSubmission in class AbstractField

Parameters:

controlName - the control name of the rendered element (used to find the correct parameter in the request)

ignoreBlankInput

protected boolean ignoreBlankInput()

Should blank input be ignored (after validation)? This will be true for PasswordField.

isRequired

public boolean isRequired()

Description copied from class: AbstractField

Returns false; most components do not support declarative validation.

Specified by:

isRequired in interface Field

Overrides:

isRequired in class AbstractField

Returns:

true if a non-blank value is required for the field

getWidth

protected final String getWidth()

Looks for a Width annotation and, if present, returns its value as a string.

Returns:

the indicated width, or null if the annotation is not present