vanillajs-browser-helpers/delegate.js

Collection of convenience code snippets (helpers) that aims to make it a little easier to work with vanilla JS in the browser

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.delegateHandler = void 0;
var isEventTarget_1 = __importDefault(require("./isEventTarget"));
var on_1 = __importDefault(require("./on"));
var off_1 = __importDefault(require("./off"));
var matches_1 = __importDefault(require("./matches"));
/**
 * Creates a function that triggers the given handler if the current event target
 * matches the given selector
 *
 * @param selector - CSS Selector that matches the element to delegate the event to
 * @param handler - Handler to trigger if selector selector match
 * @return The delegate event handler
 *
 * @example
 *
 * ```ts
 * const handler = delegateHandler('.my-element', (e: Event) => {});
 * document.addEventHandler('click', handler);
 * ```
 */
function delegateHandler(selector, handler) {
    var cb = 'handleEvent' in handler
        ? handler.handleEvent
        : handler;
    return function (e) {
        var target = e.target;
        while (target && !matches_1.default(target, selector)) {
            var parent_1 = target.parentElement;
            if (!parent_1) {
                return;
            }
            target = parent_1;
        }
        var evt = e;
        evt.delegateTarget = target;
        return cb.call(target, evt);
    };
}
exports.delegateHandler = delegateHandler;
function delegate(target, eventNames, selector, handler, options) {
    if (!isEventTarget_1.default(target)) {
        options = handler;
        handler = selector;
        selector = eventNames;
        eventNames = target;
        target = document;
    }
    var delHandler = delegateHandler(selector, handler);
    on_1.default(target, eventNames, delHandler, options);
    return function () { return off_1.default(target, eventNames, delHandler); };
}
exports.default = delegate;