[Refactoring] Teact: Refactor dom-events and better debug

This commit is contained in:
Alexander Zinchuk 2022-01-05 17:45:58 +01:00
parent 846b47cb32
commit f156be13ce
3 changed files with 65 additions and 47 deletions

View File

@ -1,102 +1,103 @@
import { DEBUG } from '../../config';
type Handler = (e: Event) => void;
type DelegationRegistry = Map<HTMLElement, Handler>;
const NON_BUBBLEABLE_EVENTS = new Set(['scroll', 'mouseenter', 'mouseleave']);
const delegationRegistry: Record<string, Map<HTMLElement, Handler>> = {};
const delegatedEventsByElement = new Map<HTMLElement, Set<string>>();
const documentEventCounters: Record<string, number> = {};
const delegationRegistryByEventType: Record<string, DelegationRegistry> = {};
const delegatedEventTypesByElement = new Map<HTMLElement, Set<string>>();
export function addEventListener(element: HTMLElement, propName: string, handler: Handler, asCapture = false) {
const eventName = resolveEventName(propName, element);
if (canUseEventDelegation(eventName, element, asCapture)) {
addDelegatedListener(eventName, element, handler);
const eventType = resolveEventType(propName, element);
if (canUseEventDelegation(eventType, element, asCapture)) {
addDelegatedListener(eventType, element, handler);
} else {
element.addEventListener(eventName, handler, asCapture);
element.addEventListener(eventType, handler, asCapture);
}
}
export function removeEventListener(element: HTMLElement, propName: string, handler: Handler, asCapture = false) {
const eventName = resolveEventName(propName, element);
if (canUseEventDelegation(eventName, element, asCapture)) {
removeDelegatedListener(eventName, element);
const eventType = resolveEventType(propName, element);
if (canUseEventDelegation(eventType, element, asCapture)) {
removeDelegatedListener(eventType, element);
} else {
element.removeEventListener(eventName, handler, asCapture);
element.removeEventListener(eventType, handler, asCapture);
}
}
function resolveEventName(propName: string, element: HTMLElement) {
const eventName = propName
function resolveEventType(propName: string, element: HTMLElement) {
const eventType = propName
.replace(/^on/, '')
.replace(/Capture$/, '').toLowerCase();
if (eventName === 'change' && element.tagName !== 'SELECT') {
if (eventType === 'change' && element.tagName !== 'SELECT') {
// React behavior repeated here.
// https://stackoverflow.com/questions/38256332/in-react-whats-the-difference-between-onchange-and-oninput
return 'input';
}
if (eventName === 'doubleclick') {
if (eventType === 'doubleclick') {
return 'dblclick';
}
// Replace focus/blur by their "bubbleable" versions
if (eventName === 'focus') {
if (eventType === 'focus') {
return 'focusin';
}
if (eventName === 'blur') {
if (eventType === 'blur') {
return 'focusout';
}
return eventName;
return eventType;
}
function canUseEventDelegation(realEventName: string, element: HTMLElement, asCapture: boolean) {
function canUseEventDelegation(realEventType: string, element: HTMLElement, asCapture: boolean) {
return (
!asCapture
&& !NON_BUBBLEABLE_EVENTS.has(realEventName)
&& !NON_BUBBLEABLE_EVENTS.has(realEventType)
&& element.tagName !== 'VIDEO'
&& element.tagName !== 'IFRAME'
);
}
function addDelegatedListener(eventName: string, element: HTMLElement, handler: Handler) {
if (!documentEventCounters[eventName]) {
documentEventCounters[eventName] = 0;
document.addEventListener(eventName, handleEvent);
function addDelegatedListener(eventType: string, element: HTMLElement, handler: Handler) {
if (!documentEventCounters[eventType]) {
documentEventCounters[eventType] = 0;
document.addEventListener(eventType, handleEvent);
}
resolveDelegationRegistryForName(eventName).set(element, handler);
resolveDelegatedEventsForElement(element).add(eventName);
documentEventCounters[eventName]++;
resolveDelegationRegistry(eventType).set(element, handler);
resolveDelegatedEventTypes(element).add(eventType);
documentEventCounters[eventType]++;
}
function removeDelegatedListener(eventName: string, element: HTMLElement) {
documentEventCounters[eventName]--;
if (!documentEventCounters[eventName]) {
function removeDelegatedListener(eventType: string, element: HTMLElement) {
documentEventCounters[eventType]--;
if (!documentEventCounters[eventType]) {
// Synchronous deletion on 0 will cause perf degradation in the case of 1 element
// which is not a real case, so it's ok to do it this way
document.removeEventListener(eventName, handleEvent);
document.removeEventListener(eventType, handleEvent);
}
delegationRegistry[eventName].delete(element);
delegatedEventsByElement.get(element)!.delete(eventName);
delegationRegistryByEventType[eventType].delete(element);
delegatedEventTypesByElement.get(element)!.delete(eventType);
}
export function removeAllDelegatedListeners(element: HTMLElement) {
const eventNames = delegatedEventsByElement.get(element);
if (!eventNames) {
const eventTypes = delegatedEventTypesByElement.get(element);
if (!eventTypes) {
return;
}
eventNames.forEach((eventName) => removeDelegatedListener(eventName, element));
delegatedEventsByElement.delete(element);
eventTypes.forEach((eventType) => removeDelegatedListener(eventType, element));
delegatedEventTypesByElement.delete(element);
}
function handleEvent(realEvent: Event) {
const events = delegationRegistry[realEvent.type];
const events = delegationRegistryByEventType[realEvent.type];
if (events) {
let furtherCallsPrevented = false;
@ -142,29 +143,46 @@ function handleEvent(realEvent: Event) {
}
}
function resolveDelegationRegistryForName(eventName: string) {
if (!delegationRegistry[eventName]) {
delegationRegistry[eventName] = new Map();
function resolveDelegationRegistry(eventType: string) {
if (!delegationRegistryByEventType[eventType]) {
delegationRegistryByEventType[eventType] = new Map();
}
return delegationRegistry[eventName];
return delegationRegistryByEventType[eventType];
}
function resolveDelegatedEventsForElement(element: HTMLElement) {
const existing = delegatedEventsByElement.get(element);
function resolveDelegatedEventTypes(element: HTMLElement) {
const existing = delegatedEventTypesByElement.get(element);
if (existing) {
return existing;
}
const newSet = new Set<string>();
delegatedEventsByElement.set(element, newSet);
delegatedEventTypesByElement.set(element, newSet);
return newSet;
}
if (DEBUG) {
document.addEventListener('dblclick', () => {
const documentListenersCount = Object.keys(documentEventCounters).length;
const delegatedHandlersCount1 = Object.values(documentEventCounters)
.reduce((acc, counter) => acc + counter, 0);
const delegationRegistriesCount = Object.keys(delegationRegistryByEventType).length;
const delegatedHandlersCount2 = Object.values(delegationRegistryByEventType)
.reduce((acc, delegationRegistry) => acc + delegationRegistry.size, 0);
const delegationElementsCount = delegatedEventTypesByElement.size;
const delegatedEventTypesCount = Array.from(delegatedEventTypesByElement.values())
.reduce((acc, eventTypes) => acc + eventTypes.size, 0);
// eslint-disable-next-line no-console
console.log('DELEGATED EVENTS', { delegationRegistry, delegatedEventsByElement, documentEventCounters });
console.warn('DELEGATED EVENTS STATS', {
delegatedHandlersCount1,
delegatedHandlersCount2,
delegatedEventTypesCount,
delegationRegistriesCount,
delegationElementsCount,
documentListenersCount,
});
});
}

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@ -250,7 +250,7 @@ const DEBUG_components: AnyLiteral = {};
document.addEventListener('dblclick', () => {
// eslint-disable-next-line no-console
console.log('COMPONENTS', orderBy(Object.values(DEBUG_components), 'renderCount', 'desc'));
console.warn('COMPONENTS', orderBy(Object.values(DEBUG_components), 'renderCount', 'desc'));
});
export function renderComponent(componentInstance: ComponentInstance) {

View File

@ -221,7 +221,7 @@ if (DEBUG) {
document.addEventListener('dblclick', () => {
// eslint-disable-next-line no-console
console.log(
console.warn(
'GLOBAL CONTAINERS',
orderBy(
Array.from(containers.values())