ethers.js/packages/experimental/src.ts/metamask-provider.ts
2020-04-27 06:31:43 -04:00

77 lines
2.2 KiB
TypeScript

"use strict";
import { ethers } from "ethers";
import { version } from "./_version";
const logger = new ethers.utils.Logger(version);
export class MetamaskProvider extends ethers.providers.Web3Provider {
_pollingAccount: any;
_pollAccountFunc: () => void;
constructor(ethereum?: ethers.providers.ExternalProvider) {
if (!ethereum) {
ethereum = (<any>global).ethereum;
if (!ethereum) {
logger.throwError("could not auto-detect global.ethereum", ethers.errors.UNSUPPORTED_OPERATION, {
operation: "window.ethereum"
});
}
}
super(ethereum);
let _account: string = null;
ethers.utils.defineReadOnly(this, "_pollAccountFunc", () => {
let account: string = null;
if (account === _account) { return; }
console.log("poll");
this.emit("account", account, _account);
_account = account;
});
super(ethereum);
}
getSigner(addressOrIndex?: string | number): ethers.providers.JsonRpcSigner {
if (!this.enabled) { return null }
return super.getSigner(addressOrIndex);
}
get enabled(): boolean {
return false;
}
_startPollingAccount(): void {
if (this._pollingAccount) { return; }
console.log("start polling for account changes including to/from null");
this._pollingAccount = setInterval(this._pollAccountFunc, 1000);
}
_stopPollingAccount(): void {
if (!this._pollingAccount) { return; }
console.log("stop polling for account changes including to/from null");
clearInterval(this._pollingAccount);
this._pollingAccount = null;
}
on(eventName: ethers.providers.EventType, listener: ethers.providers.Listener): this {
super.on(eventName, listener);
if (this.listenerCount("account") > 0) {
this._startPollingAccount();
}
return this;
}
off(eventName: ethers.providers.EventType, listener?: ethers.providers.Listener): this {
super.off(eventName, listener);
if (this.listenerCount("account") === 0) {
this._stopPollingAccount();
}
return this;
}
}