puppeteer/src/QueryHandler.ts
2020-05-07 12:54:55 +02:00

85 lines
2.4 KiB
TypeScript

/**
* Copyright 2020 Google Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
export interface QueryHandler {
(element: Element | Document, selector: string):
| Element
| Element[]
| NodeListOf<Element>;
}
const _customQueryHandlers = new Map<string, QueryHandler>();
export function registerCustomQueryHandler(
name: string,
handler: Function
): void {
if (_customQueryHandlers.get(name))
throw new Error(`A custom query handler named "${name}" already exists`);
const isValidName = /^[a-zA-Z]+$/.test(name);
if (!isValidName)
throw new Error(`Custom query handler names may only contain [a-zA-Z]`);
_customQueryHandlers.set(name, handler as QueryHandler);
}
/**
* @param {string} name
*/
export function unregisterCustomQueryHandler(name: string): void {
_customQueryHandlers.delete(name);
}
export function customQueryHandlers(): Map<string, QueryHandler> {
return _customQueryHandlers;
}
export function clearQueryHandlers(): void {
_customQueryHandlers.clear();
}
export function getQueryHandlerAndSelector(
selector: string,
defaultQueryHandler: QueryHandler
): { updatedSelector: string; queryHandler: QueryHandler } {
const hasCustomQueryHandler = /^[a-zA-Z]+\//.test(selector);
if (!hasCustomQueryHandler)
return { updatedSelector: selector, queryHandler: defaultQueryHandler };
const index = selector.indexOf('/');
const name = selector.slice(0, index);
const updatedSelector = selector.slice(index + 1);
const queryHandler = customQueryHandlers().get(name);
if (!queryHandler)
throw new Error(
`Query set to use "${name}", but no query handler of that name was found`
);
return {
updatedSelector,
queryHandler,
};
}
module.exports = {
registerCustomQueryHandler,
unregisterCustomQueryHandler,
customQueryHandlers,
getQueryHandlerAndSelector,
clearQueryHandlers,
};