@cycle/dom
Version:
The standard DOM Driver for Cycle.js, based on Snabbdom
74 lines • 2.41 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
var xstream_1 = require("xstream");
function fromEvent(element, eventName, useCapture, preventDefault, passive) {
if (useCapture === void 0) { useCapture = false; }
if (preventDefault === void 0) { preventDefault = false; }
if (passive === void 0) { passive = false; }
var next = null;
return xstream_1.Stream.create({
start: function start(listener) {
if (preventDefault) {
next = function _next(event) {
preventDefaultConditional(event, preventDefault);
listener.next(event);
};
}
else {
next = function _next(event) {
listener.next(event);
};
}
element.addEventListener(eventName, next, {
capture: useCapture,
passive: passive,
});
},
stop: function stop() {
element.removeEventListener(eventName, next, useCapture);
next = null;
},
});
}
exports.fromEvent = fromEvent;
function matchObject(matcher, obj) {
var keys = Object.keys(matcher);
var n = keys.length;
for (var i = 0; i < n; i++) {
var k = keys[i];
if (typeof matcher[k] === 'object' && typeof obj[k] === 'object') {
if (!matchObject(matcher[k], obj[k])) {
return false;
}
}
else if (matcher[k] !== obj[k]) {
return false;
}
}
return true;
}
function preventDefaultConditional(event, preventDefault) {
if (preventDefault) {
if (typeof preventDefault === 'boolean') {
event.preventDefault();
}
else if (isPredicate(preventDefault)) {
if (preventDefault(event)) {
event.preventDefault();
}
}
else if (typeof preventDefault === 'object') {
if (matchObject(preventDefault, event)) {
event.preventDefault();
}
}
else {
throw new Error('preventDefault has to be either a boolean, predicate function or object');
}
}
}
exports.preventDefaultConditional = preventDefaultConditional;
function isPredicate(fn) {
return typeof fn === 'function';
}
//# sourceMappingURL=fromEvent.js.map