yomichan/ext/fg/js/frontend-api-receiver.js
toasted-nutbread 6c341a13d8
Refactor frontend API classes (#482)
* Mark functions as private

* Remove constructor side effects

* Use safer handler invocation

* Mark functions as private

* Mark fields as private

* Update BackendApiForwarder public API
2020-05-02 12:50:44 -04:00

62 lines
1.9 KiB
JavaScript

/*
* Copyright (C) 2019-2020 Yomichan Authors
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
class FrontendApiReceiver {
constructor(source='', handlers=new Map()) {
this._source = source;
this._handlers = handlers;
}
prepare() {
chrome.runtime.onConnect.addListener(this._onConnect.bind(this));
}
_onConnect(port) {
if (port.name !== 'frontend-api-receiver') { return; }
port.onMessage.addListener(this._onMessage.bind(this, port));
}
_onMessage(port, {id, action, params, target, senderId}) {
if (target !== this._source) { return; }
const handler = this._handlers.get(action);
if (typeof handler !== 'function') { return; }
this._sendAck(port, id, senderId);
this._invokeHandler(handler, params, port, id, senderId);
}
async _invokeHandler(handler, params, port, id, senderId) {
try {
const result = await handler(params);
this._sendResult(port, id, senderId, {result});
} catch (error) {
this._sendResult(port, id, senderId, {error: errorToJson(error)});
}
}
_sendAck(port, id, senderId) {
port.postMessage({type: 'ack', id, senderId});
}
_sendResult(port, id, senderId, data) {
port.postMessage({type: 'result', id, senderId, data});
}
}