Deno scrapper for holland2stay residences

README.md

Scrapper house

Deno program to scrap the housing site for new houses (after getting the initial state).

How to compile

You can generate an executable by running the following

deno compile --allow-net --allow-run --allow-read --allow-env main.ts

How to run

Two env vars are needed SEND_EMAIL and PWD to send emails. If no .env is provided you can set those before calling the script

# Run script with email & notification
deno run --allow-net --allow-run --allow-read --allow-env main.ts --notify --email <email>

# Run script with notification ony
SEND_EMAIL=<email>; PWD=<pwd> ; deno run --allow-net --allow-run --allow-env --allow-read main.ts --notify

# Run script with no notifications at all
deno run --allow-net --allow-run --allow-read --allow-env main.ts

# Run compiled script with notification & 2 emails
./scrapper_house --notify --email <email_1> --email <email_2>

main.ts

import { DOMParser } from "https://deno.land/x/deno_dom/deno-dom-wasm.ts";
import { notify, Notification } from "https://deno.land/x/notifier/mod.ts";
import { SmtpClient } from "https://deno.land/x/smtp/mod.ts";
import "https://deno.land/x/dotenv/load.ts";
import { parse } from "https://deno.land/std@0.168.0/flags/mod.ts";

const url =
  "https://holland2stay.com/residences.html?available_to_book=179,336&city=29";

let houses: string[] = [];
const sleep = (ms: number) => new Promise((resolve) => setTimeout(resolve, ms));

async function sendEmail(subject: string, content: string, emails: string[]) {
  const client = new SmtpClient();

  const SEND_EMAIL = Deno.env.get("SEND_EMAIL");
  const SEND_PWD = Deno.env.get("SEND_PWD");

  if (!SEND_EMAIL || !SEND_PWD)
    throw new Error(
      "To send email you need to setup both SEND_EMAIL and PWD vars"
    );

  const connectConfig = {
    hostname: "smtp.gmail.com",
    port: 465,
    username: SEND_EMAIL,
    password: SEND_PWD,
  };

  await client.connectTLS(connectConfig);

  for (const email of emails) {
    await client.send({
      from: SEND_EMAIL,
      to: email,
      subject: subject,
      content: "",
      html: content,
    });
  }
  await client.close();
}

async function check_houses(notification: boolean, emails: string[]) {
  try {
    const res = await fetch(url);
    const html = await res.text();
    const document = new DOMParser().parseFromString(html, "text/html");

    if (document) {
      const houseElements = document.getElementsByClassName("regi-item");

      for (const house of houseElements) {
        const houseTitle = house.querySelector("h4");

        if (!houseTitle)
          throw new Error(
            "Houses don't have an H4 set anymore. Update the filter"
          );

        const title = houseTitle.textContent.trim().toLowerCase();
        const houseName = title
          .split(" ")
          .slice(0, -1)
          .join(" ")
          .trim()
          .split(" ")
          .join("-")
          .replaceAll(".", "-")
          .replaceAll("--", "-");

        if (!houses.includes(title)) {
          houses.push(title);
          const notif_title = `New house found! ${title}`;
          const notif_text = `Go to <link>https://holland2stay.com/${houseName}.html<link> or check the generic page <link>${url}<link>.`;
          console.log(notif_title);

          if (notification) {
            const notif: Notification = {
              title: notif_title,
              message: notif_text,
              sound: "device-added",
            };
            await notify(notif);

            if (emails) sendEmail(notif_title, notif_text, emails);
          }
        }
      }
    } else {
      console.log("No document found");
    }
  } catch (error) {
    console.log(error);
  }
}

const flagToAliasMap = {
  notify: "n",
  email: "e",
};

const flags: { [x: string]: unknown } = parse(Deno.args, {
  boolean: ["notify"],
  string: ["email"],
  collect: ["email"],
  alias: flagToAliasMap,
});

await check_houses(false, flags.email as string[]);

while (true) {
  await check_houses(flags.notify as boolean, flags.email as string[]);
  await sleep(10000);
  console.log(`Checking again... ${new Date()}`);
}