swaf/src/ApplicationComponent.ts

54 lines
1.5 KiB
TypeScript
Raw Normal View History

2020-04-22 15:52:17 +02:00
import {Express, Router} from "express";
import Logger from "./Logger";
import {sleep} from "./Utils";
import Application from "./Application";
2020-04-22 15:52:17 +02:00
export default abstract class ApplicationComponent<T> {
private val?: T;
protected app?: Application;
2020-04-22 15:52:17 +02:00
public abstract async start(app: Express, router: Router): Promise<void>;
public abstract async stop(): Promise<void>;
protected export(val: T) {
this.val = val;
}
public import(): T {
if (!this.val) throw 'Cannot import if nothing was exported.';
return this.val;
}
public setApp(app: Application) {
this.app = app;
}
2020-04-22 15:52:17 +02:00
protected async prepare(name: string, prepare: () => Promise<void>): Promise<void> {
let err;
do {
try {
await prepare();
err = null;
} catch (e) {
err = e;
Logger.error(err, `${name} failed to prepare; retrying in 5s...`)
await sleep(5000);
}
} while (err);
Logger.info(`${name} ready!`);
}
protected async close(thingName: string, thing: any, fn: Function): Promise<void> {
try {
await new Promise((resolve, reject) => fn.call(thing, (err: any) => {
if (err) reject(err);
else resolve();
}));
Logger.info(`${thingName} closed.`);
} catch (e) {
Logger.error(e, `An error occurred while closing the ${thingName}.`);
}
}
}