Event object

BaseEvent object

The following table describes the attributes of a BaseEvent object.

type

The type of the event.

timeStamp

The timestamp when the event object is generated.

target

The source component object where the event is triggered. The following table describes the attributes of a source component object.

You can use dataset to define data in a component. After an event in the component is triggered, the defined data is transferred to the logical layer. Each data item in the dataset starts with data-. The words that follow are connected by hyphens -. All the letters must be lowercase and uppercase letters are automatically converted to lowercase letters. For example, for a string data-element-type, the event.target.dataset method converts this string to camel case elementType.

Code sample:

<view data-alpha-beta="1" data-alphaBeta="2" onTap="bindViewTap"> DataSet Test </view>

Page({
  bindViewTap:function(event) {
    event.target.dataset.alphaBeta === 1; // - Convert the string to camel case.
    event.target.dataset.alphabeta === 2; // Convert uppercase letters to lowercase letters.
  },
});

CustomEvent object

A CustomEvent object inherits from a BaseEvent object. The following table describes the attribute of a CustomEvent object.

detail

The data carried by the custom event. When an event is triggered in a form component, the generated event object carries user input information. For example, after the onChange event in the switch component is triggered, you can use event.detail.value to obtain the status value that is selected by the user. When an error event is triggered in a media component, the generated event object carries the error information. For more information, see event descriptions in component documents.

TouchEvent object

A TouchEvent object inherits from a BaseEvent object. The following table describes the attributes of a TouchEvent object.

The touches attribute is an array of Touch objects that represent the current fixed touch points on the screen. Note that for a Canvas TouchEvent object, the touches attribute is an array of CanvasTouch objects.

The data format of the “changedTouches” attribute is the same as the data format of the “touches” attribute. The “changedTouches” attribute represents the current changed touch points, such as touchstart, touchmove, touchend, and touchcancel.

Touch object

CanvasTouch object