74

PrimeFaces Ajax

Primefaces provides built-in Ajax support. It provides various attributes like update, event, listener etc. Here, we are creating an example that explains ajax attributes.

Ajax Attributes

The following table contains Ajax attributes.

Attribute	Default value	Return type	Description
listener	null	MethodExpr	It is used to process in partial request.
Immediate	false	boolean	It returns a boolean value that determines the phaseId, when true actions are processed at apply_request_values, when false at invoke_application phase.
async	false	boolean	When set to true, ajax requests are not queued.
process	null	String	It is used to process in partial request.
update	null	String	It is used to update with ajax.
onstart	null	String	It is used to execute before ajax request is begins.
oncomplete	null	String	It is used to execute when ajax request is completed.
onsuccess	null	String	It is used to execute when ajax request succeeds.
delay	null	String	It is used to set time to delay. If less than delay milliseconds elapses between calls to request() only the most recent one is sent and all other requests are discarded. If this option is not specified, or if the value of delay is the literal string ‘none’ without the quotes, no delay is used.
partialSubmit	false	boolean	Enables serialization of values belonging to the partially processed components only.
partialSubmitFilter	null	String	Selector to use when partial submit is on, default is “:input” to select all descendant inputs of a partially processed components.
event	null	String	Client side event to trigger ajax request.

---

Ajax Basic

This example explains a built-in Ajax usage in the application. It updates the back-end value and displays output by using Ajax.

This example includes a JSF page and a ManagedBean.

JSF File

// ajax-basic.xhtml

ManagedBean

// User.java

Output:

After entering value and pressing submit, it produce the following output.