74 lines
2.4 KiB
TypeScript
74 lines
2.4 KiB
TypeScript
// Copyright 2019 @polkadot/extension authors & contributors
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// This software may be modified and distributed under the terms
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// of the Apache-2.0 license. See the LICENSE file for details.
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import { MessageTypes } from '../background/types';
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import { WindowInjected } from './types';
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import events, { eventTarget } from '../events';
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import Injected from './Injected';
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// when sending a message from the injector to the expension, we
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// - create an event - this we send to the loader
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// - the loader takes this evend and uses sendMessage to the extension background
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// - on respoinse, the loader creates a reponse event
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// - this injector, reads listends on the events, maps it to the original
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// - resolves/rejects the promise with the result
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type Callbacks = {
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[index: number]: {
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resolve: (data: any) => void,
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reject: (error: Error) => void
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}
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};
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const callbacks: Callbacks = {};
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let idCounter = 0;
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// a generic message sender that creates an event, returning a promise that will resolve once
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// the event is resolved (by the response listener just below this)
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function sendMessage (message: MessageTypes, request: any = null): Promise<any> {
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return new Promise((resolve, reject) => {
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const id = ++idCounter;
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callbacks[id] = { resolve, reject };
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document.dispatchEvent(
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new CustomEvent(events.request, { detail: { id, message, request } })
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);
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});
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}
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// setup a response listener (events created by the loader for extension responses)
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eventTarget.addEventListener(events.response, (event) => {
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const response = (event as CustomEvent).detail;
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const promise = callbacks[response.id];
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if (!promise) {
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console.error(`Uknown response: ${JSON.stringify(response)}`);
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return;
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}
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delete callbacks[response.id];
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if (response.error) {
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promise.reject(new Error(response.error));
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} else {
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promise.resolve(response.response);
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}
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});
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// small helper with the typescript types, just cast window
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const windowInject = window as WindowInjected;
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// don't clobber the existing object, we will add it it (or create as needed)
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windowInject.injectedWeb3 = windowInject.injectedWeb3 || {};
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// add our enable function
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windowInject.injectedWeb3['polkadot-js'] = {
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name: 'polkadot-js', // process.env.PKG_NAME as string,
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version: process.env.PKG_VERSION as string,
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enable: (origin: string): Promise<Injected> =>
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sendMessage('authorize.tab', { origin }).then(() => new Injected(sendMessage))
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};
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