mapcomplete/scripts/serverLdScrape.ts

55 lines
2.4 KiB
TypeScript

import Script from "../scripts/Script"
import { Server } from "./server"
import { Utils } from "../src/Utils"
import parse from "node-html-parser"
class ServerLdScrape extends Script {
constructor() {
super("Starts a server which fetches a webpage and returns embedded LD+JSON")
}
async main(args: string[]): Promise<void> {
const port = Number(args[0] ?? 2346)
const cache: Record<string, { date: Date; contents: any }> = {}
new Server(port, {}, [
{
mustMatch: "extractgraph",
mimetype: "application/ld+json",
async handle(content, searchParams: URLSearchParams) {
const url = searchParams.get("url")
if (cache[url] !== undefined) {
const { date, contents } = cache[url]
console.log(">>>", date, contents)
// In seconds
const tdiff = (new Date().getTime() - (date?.getTime() ?? 0)) / 1000
if (tdiff < 24 * 60 * 60) {
return JSON.stringify(contents)
}
}
const dloaded = await Utils.download(url, {
"User-Agent":
"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1500.52 Safari/537.36", // MapComplete/openstreetmap scraper; pietervdvn@posteo.net; https://github.com/pietervdvn/MapComplete",
})
// return dloaded
const parsed = parse(dloaded)
const scripts = Array.from(parsed.getElementsByTagName("script"))
for (const script of scripts) {
const tp = script.attributes["type"]
if (tp !== "application/ld+json") {
continue
}
try {
const snippet = JSON.parse(script.textContent)
snippet["@base"] = url
cache[url] = { contents: snippet, date: new Date() }
return JSON.stringify(snippet)
} catch (e) {
console.error(e)
}
}
},
},
])
}
}
new ServerLdScrape().run()