# Custom triggers

By default, any change to the content will trigger a model update and form validation. You can

override this behavior using the {@link ng.directive:ngModelOptions ngModelOptions} directive to

bind only to specified list of events. I.e. `ng-model-options="{ updateOn: "blur" }"` will update

and validate only after the control loses focus. You can set several events using a space delimited

list. I.e. `ng-model-options="{ updateOn: 'mousedown blur' }"`

If you want to keep the default behavior and just add new events that may trigger the model update

and validation, add "default" as one of the specified events.

I.e. `ng-model-options="{ updateOn: 'default blur' }"`

The following example shows how to override immediate updates. Changes on the inputs within the form will update the model

only when the control loses focus (blur event).

<example>

<file name="index.html">

<div ng-controller="ControllerUpdateOn">

<form>

Name:

<input type="text" ng-model="user.name" ng-model-options="{ updateOn: "blur" }" /><br />

Other data:

<input type="text" ng-model="user.data" /><br />

</form>

<pre>username = "{{user.name}}"</pre>

</div>

</file>

<file name="script.js">

function ControllerUpdateOn($scope) {

$scope.user = {};

}

</file>

</example>

# Non-immediate (debounced) model updates

You can delay the model update/validation by using the `debounce` key with the

{@link ng.directive:ngModelOptions ngModelOptions} directive. This delay will also apply to

parsers, validators and model flags like `$dirty` or `$pristine`.

I.e. `ng-model-options="{ debounce: 500 }"` will wait for half a second since

the last content change before triggering the model update and form validation.

If custom triggers are used, custom debouncing timeouts can be set for each event using an object

in `debounce`. This can be useful to force immediate updates on some specific circumstances

(like blur events).

I.e. `ng-model-options="{ updateOn: 'default blur', debounce: { default: 500, blur: 0 } }"`

If those attributes are added to an element, they will be applied to all the child elements and controls that inherit from it unless they are

overridden.

This example shows how to debounce model changes. Model will be updated only 250 milliseconds after last change.

<example>

<file name="index.html">

<div ng-controller="ControllerUpdateOn">

<form>

Name:

<input type="text" ng-model="user.name" ng-model-options="{ debounce: 250 }" /><br />

</form>

<pre>username = "{{user.name}}"</pre>

</div>

</file>

<file name="script.js">

function ControllerUpdateOn($scope) {

$scope.user = {};

}

</file>

</example>