viewParam (OmniFaces VDL Documentation - Generated Documentation)

Description:

o:viewParam is a component that extends the standard viewParam and provides a stateless mode of operation and a default for the label atrribute. When the label attribute is omitted, the name attribute will be used instead.
The standard UIViewParameter implementation calls the model setter again after postback. This is not always desired when being bound to a view scoped beans and can lead to performance problems when combined with an expensive converter.
To solve this, this component by default stores the submitted value as a component property instead of in the model (and thus in the view state in case the binding is to a view scoped bean).
You can use it the same way as <f:viewParam>, you only need to change f: by o:.

Component Information

Info Value

Component Type org.omnifaces.component.input.ViewParam

Handler Class None

Renderer Type None

Description None

Component Information
Info	Value
Component Type	`org.omnifaces.component.input.ViewParam`
Handler Class	None
Renderer Type	None
Description	None

Attributes
Name	Required	Type	Description
`name`	`true`	`javax.el.ValueExpression` (must evaluate to `java.lang.String`)	The name of the request parameter from which the value for this component is retrieved on an initial request or to override the stored value on a postback.
`converter`	`false`	`javax.el.ValueExpression` (must evaluate to `javax.faces.convert.Converter`)	Converter instance registered with this component.
`converterMessage`	`false`	`javax.el.ValueExpression` (must evaluate to `java.lang.String`)	A ValueExpression enabled attribute that, if present, will be used as the text of the converter message, replacing any message that comes from the converter.
`id`	`false`	`javax.el.ValueExpression` (must evaluate to `java.lang.String`)	The component identifier for this component. This value must be unique within the closest parent component that is a naming container.
`required`	`false`	`javax.el.ValueExpression` (must evaluate to `boolean`)	Flag indicating that the user is required to provide a submitted value for this input component. This component extends the behavior of this by only making this required for a non-faces request.
`requiredMessage`	`false`	`javax.el.ValueExpression` (must evaluate to `java.lang.String`)	A ValueExpression enabled attribute that, if present, will be used as the text of the validation message for the "required" facility, if the "required" facility is used.
`validator`	`false`	`javax.el.MethodExpression` (signature must match `void validate(javax.faces.context.FacesContext, javax.faces.component.UIComponent, java.lang.Object)`)	MethodExpression representing a validator method that will be called during Process Validations to perform correctness checks on the value of this component. The expression must evaluate to a public method that takes FacesContext, UIComponent, and Object parameters, with a return type of void.
`validatorMessage`	`false`	`javax.el.ValueExpression` (must evaluate to `java.lang.String`)	A ValueExpression enabled attribute that, if present, will be used as the text of the validator message, replacing any message that comes from the validator.
`value`	`false`	`javax.el.ValueExpression` (must evaluate to `java.lang.Object`)	A ValueExpression to which the value of the request parameter, as determined by the name attribute, is bound. The resolved value of this expression is used when encoding the view parameter into a bookmarkable link or redirect URL with view parameter encoding enabled. If this attribute is omitted, the value of the request parameter will instead be the local value of the UIViewParameter.
`valueChangeListener`	`false`	`javax.el.MethodExpression` (signature must match `void valueChange(javax.faces.event.ValueChangeEvent)`)	MethodExpression representing a value change listener method that will be notified when a new value has been set for this input component. The expression must evaluate to a public method that takes a `ValueChangeEvent` parameter, with a return type of void, or to a public method that takes no arguments with a return type of void. In the latter case, the method has no way of easily knowing what the new value is, but this can be useful in cases where a notification is needed that "this value changed".
`maxlength`	`false`	`javax.el.ValueExpression` (must evaluate to `int`)	The maximum number of characters that may be entered in this field.
`binding`	`false`	`javax.el.ValueExpression` (must evaluate to `javax.faces.component.UIComponent`)	The ValueExpression linking this component to a property in a backing bean
`for`	`false`	`javax.el.ValueExpression` (must evaluate to `java.lang.String`)	If present, this attribute refers to the value of one of the exposed attached objects within the composite component inside of which this tag is nested.

o

Tag viewParam