listener-rss/src/listener-rss.ts

104 lines
2.9 KiB
TypeScript

import Parser from "rss-parser/index";
import { ListenerRSSInfos as ListenerInfo } from "./Models/ListenerRSSInfos";
import EventEmitter from "events";
const DEFAULT_TIMELOOP: number = 5 * 60; // default timeloop is 5 min
/**
* Emit 'update' when he's making a fetch during the start fun
* Emit 'update_err' when the fetch has an issue
*/
export class ListenerRss extends EventEmitter {
name: string = "";
address: string = "";
timeloop: number = DEFAULT_TIMELOOP; // time in seconds
customfields?: { [key: string]: string[] | string };
// private fields
parser: Parser | undefined = undefined;
loopRunning: boolean = false;
/**
* @brief constructor
* @param config ListenerRSSInfos interface who's contain the ListenerInfos
*/
constructor(config: ListenerInfo) {
super();
this.setData(config);
this.setParser();
}
/**
* @brief Private function. Is useed to initilize the parser object with the customfields var
*/
setParser() {
// set parser
this.parser = new Parser(
this.customfields !== undefined
? {
customFields: {
feed: [],
item: Object.entries(this.customfields).map(([, value]) => {
return Array.isArray(value) ? value[0] : value;
}),
},
}
: {}
); // if customfield is set -> let's set the parser with, else let the option empty
}
/**
* @brief Private function. Initialized the listener with an ListenerRSSInfos interface
* @param infos ListenerRSSInfos interface who's contain the ListenerInfos
*/
setData(infos: ListenerInfo) {
// Set data
this.name = infos.name;
this.address = infos.address;
this.timeloop =
infos.timeloop === undefined ? DEFAULT_TIMELOOP : infos.timeloop;
this.customfields = infos.customfields;
}
/**
* @brief use the parseURL function from rss-parser with the objects datas
* @return return a promise with the received data
*/
fetchRSS(): Promise<Parser.Output<any>> {
if (this.parser !== undefined && this.address !== undefined) {
return this.parser.parseURL(this.address).catch((err) => {
throw new Error("bad address or no access : " + err);
});
} else throw new Error("listener must be first initialized");
}
/**
* @brief call the callback function each looptime
* @param callback function who's going to be called with the latest get
*/
start(): void {
this.loopRunning = true;
const fun: () => void = () => {
this.fetchRSS()
.then((obj: { [key: string]: any }) => this.emit("update", obj))
.catch((err) => this.emit("update_err", err));
};
(async () => {
while (this.loopRunning) {
await fun();
await new Promise((res) => setTimeout(res, this.timeloop * 1000));
}
})();
}
/**
* @brief stop the async function
*/
stop(): void {
this.loopRunning = false;
}
}