angular-cn/packages/elements/src/utils.ts

137 lines
4.4 KiB
TypeScript

/**
* @license
* Copyright Google LLC All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {ComponentFactoryResolver, Injector, Type} from '@angular/core';
/**
* Provide methods for scheduling the execution of a callback.
*/
export const scheduler = {
/**
* Schedule a callback to be called after some delay.
*
* Returns a function that when executed will cancel the scheduled function.
*/
schedule(taskFn: () => void, delay: number): () => void {
const id = setTimeout(taskFn, delay);
return () => clearTimeout(id);
},
/**
* Schedule a callback to be called before the next render.
* (If `window.requestAnimationFrame()` is not available, use `scheduler.schedule()` instead.)
*
* Returns a function that when executed will cancel the scheduled function.
*/
scheduleBeforeRender(taskFn: () => void): () => void {
// TODO(gkalpak): Implement a better way of accessing `requestAnimationFrame()`
// (e.g. accounting for vendor prefix, SSR-compatibility, etc).
if (typeof window === 'undefined') {
// For SSR just schedule immediately.
return scheduler.schedule(taskFn, 0);
}
if (typeof window.requestAnimationFrame === 'undefined') {
const frameMs = 16;
return scheduler.schedule(taskFn, frameMs);
}
const id = window.requestAnimationFrame(taskFn);
return () => window.cancelAnimationFrame(id);
},
};
/**
* Convert a camelCased string to kebab-cased.
*/
export function camelToDashCase(input: string): string {
return input.replace(/[A-Z]/g, char => `-${char.toLowerCase()}`);
}
/**
* Create a `CustomEvent` (even on browsers where `CustomEvent` is not a constructor).
*/
export function createCustomEvent(doc: Document, name: string, detail: any): CustomEvent {
const bubbles = false;
const cancelable = false;
// On IE11, `CustomEvent` is not a constructor.
if (typeof CustomEvent !== 'function') {
const event = doc.createEvent('CustomEvent');
event.initCustomEvent(name, bubbles, cancelable, detail);
return event;
}
return new CustomEvent(name, {bubbles, cancelable, detail});
}
/**
* Check whether the input is an `Element`.
*/
export function isElement(node: Node|null): node is Element {
return !!node && node.nodeType === Node.ELEMENT_NODE;
}
/**
* Check whether the input is a function.
*/
export function isFunction(value: any): value is Function {
return typeof value === 'function';
}
/**
* Convert a kebab-cased string to camelCased.
*/
export function kebabToCamelCase(input: string): string {
return input.replace(/-([a-z\d])/g, (_, char) => char.toUpperCase());
}
let _matches: (this: any, selector: string) => boolean;
/**
* Check whether an `Element` matches a CSS selector.
* NOTE: this is duplicated from @angular/upgrade, and can
* be consolidated in the future
*/
export function matchesSelector(el: any, selector: string): boolean {
if (!_matches) {
const elProto = <any>Element.prototype;
_matches = elProto.matches || elProto.matchesSelector || elProto.mozMatchesSelector ||
elProto.msMatchesSelector || elProto.oMatchesSelector || elProto.webkitMatchesSelector;
}
return el.nodeType === Node.ELEMENT_NODE ? _matches.call(el, selector) : false;
}
/**
* Test two values for strict equality, accounting for the fact that `NaN !== NaN`.
*/
export function strictEquals(value1: any, value2: any): boolean {
return value1 === value2 || (value1 !== value1 && value2 !== value2);
}
/** Gets a map of default set of attributes to observe and the properties they affect. */
export function getDefaultAttributeToPropertyInputs(
inputs: {propName: string, templateName: string}[]) {
const attributeToPropertyInputs: {[key: string]: string} = {};
inputs.forEach(({propName, templateName}) => {
attributeToPropertyInputs[camelToDashCase(templateName)] = propName;
});
return attributeToPropertyInputs;
}
/**
* Gets a component's set of inputs. Uses the injector to get the component factory where the inputs
* are defined.
*/
export function getComponentInputs(
component: Type<any>, injector: Injector): {propName: string, templateName: string}[] {
const componentFactoryResolver: ComponentFactoryResolver = injector.get(ComponentFactoryResolver);
const componentFactory = componentFactoryResolver.resolveComponentFactory(component);
return componentFactory.inputs;
}