yomichan/ext/bg/js/template-renderer-frame-api.js
2020-09-19 22:19:31 -04:00

77 lines
2.5 KiB
JavaScript

/*
* Copyright (C) 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 TemplateRendererFrameApi {
constructor(templateRenderer) {
this._templateRenderer = templateRenderer;
this._windowMessageHandlers = new Map([
['renderHandlebarsTemplate', {async: true, handler: this._onRenderHandlebarsTemplate.bind(this)}]
]);
}
prepare() {
window.addEventListener('message', this._onWindowMessage.bind(this), false);
}
_onWindowMessage(e) {
const {source, data: {action, params, id}} = e;
const messageHandler = this._windowMessageHandlers.get(action);
if (typeof messageHandler === 'undefined') { return; }
this._onWindowMessageInner(messageHandler, action, params, source, id);
}
async _onWindowMessageInner({handler, async}, action, params, source, id) {
let response;
try {
let result = handler(params);
if (async) {
result = await result;
}
response = {result};
} catch (error) {
response = {error: this._errorToJson(error)};
}
if (typeof id === 'undefined') { return; }
source.postMessage({action: `${action}.response`, params: response, id}, '*');
}
async _onRenderHandlebarsTemplate({template, data, marker}) {
return await this._templateRenderer.render(template, data, marker);
}
_errorToJson(error) {
try {
if (error !== null && typeof error === 'object') {
return {
name: error.name,
message: error.message,
stack: error.stack,
data: error.data
};
}
} catch (e) {
// NOP
}
return {
value: error,
hasValue: true
};
}
}