Use Ajax in a Page

Some Visualforce components are Ajax aware. With these components, you can add Ajax behaviors to a page without writing any JavaScript.

• Implement Partial Page Updates with Command Links and Buttons

  One of the most widely used Ajax behaviors is a partial page update, in which only a specific portion of a page updates following some user action, rather than a reload of the entire page. The simplest way to implement a partial page update is to use the reRender attribute on an <apex:commandLink> or <apex:commandButton> tag. When a user clicks the button or link, only the identified component and all of its child components refresh.

• Provide Status for Asynchronous Operations

  Ajax behaviors, such as partial page updates, are asynchronous events that occur in the background while a user continues to work. With the <apex:actionStatus> component, you can display status messages that alert the user of any background activity currently in progress.

• Apply Ajax Behavior to Events on Any Component

  Implement a partial page update without using command links or buttons. For example, a user can hover over a component to trigger the update.