Form.Element

This is a collection of methods that assist in dealing with form controls. They provide ways to focus, serialize, disable/enable or extract current value from a specific control.

In Prototype, Form.Element is also aliased Field and all these methods are available directly on INPUT, SELECT and TEXTAREA elements that have been extended (see “How Prototype extends the DOM”). Therefore, these are equivalent:


Form.Element.activate('myfield')
Field.activate('myfield')
$('myfield').activate()

Naturally, you should always prefer the shortest form suitable in a situation. Most of these methods also return the element itself (as indicated by the return type) for chainability.

Methods

activate

activate(element) -> HTMLElement

Gives focus to a form control and selects its contents if it is a text input.

clear

clear(element) -> HTMLElement

Clears the contents of a text input.

disable

disable(element) -> HTMLElement

Disables a form control, effectively preventing its value to be changed until it is enabled again.

enable

enable(element) -> HTMLElement

Enables a previously disabled form control.

focus

focus(element) -> HTMLElement

Gives keyboard focus to an element.

getValue

getValue(element) -> string | array

Returns the current value of a form control. A string is returned for most controls; only multiple select boxes return an array of values. The global shortcut for this method is $F().

present

present(element) -> boolean

Returns true if a text input has contents, false otherwise.

select

select(element) -> HTMLElement

Selects the current text in a text input.

serialize

serialize(element) -> string

Creates an URL-encoded string representation of a form control in the name=value format.