Reputation: 1212
Is it possible in React to pass all event to child element.
as an example I've got a custom Button class, that (simplified) looks something like this:
class Button extends Component {
constructor (props) {
super(props);
this.onClick = this.onClick.bind(this);
}
/* .... */
onClick (ev) {
const { disabled, onClick } = this.props;
if (!disabled) {
onClick(ev);
}
}
render () {
const {
children,
disabled,
type
} = this.props;
return (
<button
disabled={disabled}
onClick={this.onClick}
ref="button"
type={type}
>{children}</button>
}
}
I don't know what events i may want to use in the future (onMouseDown, onMouseUp, onBlur, onKeyDown, onTouchStart, and so on...)
Is it possible to pass all possible events to the button element without writing out a prop for every possible event?
adding {...this.props} to the button element is not what I want because it passes all props and some props (like className which is omitted in this example) should not be passed directly.
I thought about cloning the props object and deleting the props which should not be passed directly but this feels like a hack. Does anybody know a cleaner way?
Upvotes: 3
Views: 1877
Reputation: 21
I've taken Barry127's answer and added all the event handlers from React and put them in an object.
const acceptedEventHandlersForComponentValidationFunction = {
clipBoard: [
"onCopy",
"onCut",
"onPaste",
"onCopyCapture",
"onCutCapture",
"onPasteCapture"
],
composition: [
"onCompositionEnd",
"onCompositionStart",
"onCompositionUpdate",
"onCompositionEndCapture",
"onCompositionStartCapture",
"onCompositionUpdateCapture"
],
keyboard: [
"onKeyDown",
"onKeyPress",
"onKeyUp",
"onKeyDownCapture",
"onKeyPressCapture",
"onKeyUpCapture"
],
focus: ["onFocus", "onBlur", "onFocusCapture", "onBlurCapture"],
form: [
"onChange",
"onInput",
"onInvalid",
"onReset",
"onSubmit",
"onChangeCapture",
"onInputCapture",
"onInvalidCapture",
"onResetCapture",
"onSubmitCapture"
],
generic: ["onError", "onLoad", "onErrorCapture", "onLoadCapture"],
mouse: [
"onClick",
"onContextMenu",
"onDoubleClick",
"onDrag",
"onDragEnd",
"onDragEnter",
"onDragExit",
"onDragLeave",
"onDragOver",
"onDragStart",
"onDrop",
"onMouseDown",
"onMouseEnter",
"onMouseLeave",
"onMouseMove",
"onMouseOut",
"onMouseOver",
"onMouseUp",
"onClickCapture",
"onContextMenuCapture",
"onDoubleClickCapture",
"onDragCapture",
"onDragEndCapture",
"onDragEnterCapture",
"onDragExitCapture",
"onDragLeaveCapture",
"onDragOverCapture",
"onDragStartCapture",
"onDropCapture",
"onMouseDownCapture",
"onMouseMoveCapture",
"onMouseOutCapture",
"onMouseOverCapture",
"onMouseUpCapture"
],
pointer: [
"onPointerDown",
"onPointerMove",
"onPointerUp",
"onPointerCancel",
"onGotPointerCapture",
"onLostPointerCapture",
"onPointerEnter",
"onPointerLeave",
"onPointerOver",
"onPointerOut",
"onPointerDownCapture",
"onPointerMoveCapture",
"onPointerUpCapture",
"onPointerCancelCapture",
"onGotPointerCaptureCapture",
"onLostPointerCaptureCapture",
"onPointerOverCapture",
"onPointerOutCapture"
],
selection: ["onSelect", "onSelectCapture"],
touch: [
"onTouchCancel",
"onTouchEnd",
"onTouchMove",
"onTouchStart",
"onTouchCancelCapture",
"onTouchEndCapture",
"onTouchMoveCapture",
"onTouchStartCapture"
],
ui: ["onScroll", "onScrollCapture"],
wheel: ["onWheel", "onWheelCapture"],
media: [
"onAbort",
"onCanPlay",
"onCanPlayThrough",
"onDurationChange",
"onEmptied",
"onEncrypted",
"onEnded",
"onError",
"onLoadedData",
"onLoadedMetadata",
"onLoadStart",
"onPause",
"onPlay",
"onPlaying",
"onProgress",
"onRateChange",
"onSeeked",
"onSeeking",
"onStalled",
"onSuspend",
"onTimeUpdate",
"onVolumeChange",
"onWaiting",
"onAbortCapture",
"onCanPlayCapture",
"onCanPlayThroughCapture",
"onDurationChangeCapture",
"onEmptiedCapture",
"onEncryptedCapture",
"onEndedCapture",
"onErrorCapture",
"onLoadedDataCapture",
"onLoadedMetadataCapture",
"onLoadStartCapture",
"onPauseCapture",
"onPlayCapture",
"onPlayingCapture",
"onProgressCapture",
"onRateChangeCapture",
"onSeekedCapture",
"onSeekingCapture",
"onStalledCapture",
"onSuspendCapture",
"onTimeUpdateCapture",
"onVolumeChangeCapture",
"onWaitingCapture"
],
image: ["onLoad", "onError", "onLoadCapture", "onErrorCapture"],
animation: [
"onAnimationStart",
"onAnimationEnd",
"onAnimationIteration",
"onAnimationStartCapture",
"onAnimationEndCapture",
"onAnimationIterationCapture"
],
transition: ["onTransitionEnd", "onTransitionEndCapture"],
other: ["onToggle", "onToggleCapture"]
}
/*
- Component props event handler vilidation
Return all valid events to be used on a component
{
acceptedEventHandlerTypes: [
"${event handler type}"
],
eventHandlers: {
${event}: "${callback function}" // ${event} can contain "Capture" at the end to register the event handler for the capture phase
}
}
*/
const validateComponentPropsEventHandlers = (
acceptedEventHandlerTypes,
eventHandlers = {}
) => {
if (Object.keys(eventHandlers).length == 0) {
return {}
}
// Fill eventsForSpecifiedType with only the required events
let eventsForSpecifiedType = {}
let eventsCount = 0
for (const eventHandlerType in acceptedEventHandlerTypes) {
if (
acceptedEventHandlerTypes[eventHandlerType] in
acceptedEventHandlersForComponentValidationFunction
) {
const newEvents =
acceptedEventHandlersForComponentValidationFunction[
acceptedEventHandlerTypes[eventHandlerType]
]
eventsForSpecifiedType[
acceptedEventHandlerTypes[eventHandlerType]
] = newEvents
eventsCount += newEvents.length
}
}
// Fill events
let events = {}
let eventsCountCheck = 0
const checkIfEventsCountHasBeenReached = () =>
eventsCountCheck == eventsCount
for (const eventHandler in eventHandlers) {
if (checkIfEventsCountHasBeenReached()) {
return events
}
// Append event handler to events object if it is recognised
Object.values(eventsForSpecifiedType).forEach(
(EVENT_HANDLERS) => {
if (
EVENT_HANDLERS.includes(eventHandler) &&
!(eventHandler in events)
) {
events[eventHandler] = eventHandlers[eventHandler]
eventsCountCheck += 1
}
if (checkIfEventsCountHasBeenReached()) {
return events
}
}
)
}
return events
}
// Usage
const test = () => {console.log("test")}
const events = validateComponentPropsEventHandlers(["mouse"], { onClick: test })
console.log(events)
// <button {...events}>Button</button>
Upvotes: 0
Reputation: 1212
I've written a function to iterate over the props and filter out all properties starting with 'on' this is the closest I've come so far. In case it helps anyone else:
/* helpers.js */
export function filterEvents (props, ignore = []) {
let events = {};
for (let property in props) {
if (props.hasOwnProperty(property)) {
if (property.startsWith('on') && ignore.indexOf(property) === -1) {
events[property] = props[property];
}
}
}
return events;
}
/* Tests for the filterEvents */
import { expect } from 'chai';
import { filterEvents } from './helpers';
describe('filterEvents', () => {
const props = {
className: 'someClass',
disabled: true,
onBlur: 'onBlur',
onClick: 'onClick',
onMouseDown: 'onMouseDown',
onMouseUp: 'onMouseUp'
};
it('only returns keys starting with on', () => {
const expected = {
onBlur: 'onBlur',
onClick: 'onClick',
onMouseDown: 'onMouseDown',
onMouseUp: 'onMouseUp'
};
expect(filterEvents(props)).to.deep.equal(expected);
});
it('only returns keys starting with on minus the ones in the ignore array', () => {
const expected = {
onBlur: 'onBlur',
onMouseUp: 'onMouseUp'
};
const ignore = ['onClick', 'onMouseDown'];
expect(filterEvents(props, ignore)).to.deep.equal(expected);
});
});
/* Using the function inside a component */
import { filterEvents } from './helpers'; //at the top of the components file
//Inside the render method:
const events = filterEvents(this.props, ['onClick']); //don't include onClick it's handled like the questions example
return (
<button
disabled={this.props.disabled}
onClick={this.onClick}
{...events}
>
{this.props.children}
</button>
);
Upvotes: 2