• governorkeagan@lemdro.idOPEnglish
    6·
    4 months ago

    It’s not very slow to scrape a website. Works quite well.

    That’s good to know, I’ll look into that some more. I was thinking that it might be slow if I’m having to scrape each page, every time a user changes categories (or something similar).

    The trouble with that is that it breaks easily when they change something on their site.

    I completely forgot about that :(

    • Björn Tantau@swg-empire.de
      8·
      4 months ago

      That’s good to know, I’ll look into that some more. I was thinking that it might be slow if I’m having to scrape each page, every time a user changes categories (or something similar).

      Well, it’s as slow as the website you’re scraping. Could actually be faster if you don’t have to execute a lot of bullshit JavaScript. And for the rest clever caching should help.

      In terms of technology you’re looking for XSLT, Xpath, CSS selectors and whatever parsers are available for your language of choice. Don’t ever attempt to use regex for scraping.

    • Ephera@lemmy.ml
      3·
      4 months ago

      You should look into how the webpage is built. If it’s a static HTML webpage pre-rendered on the server, then you would have to scrape the HTML to extract the info.

      However, many more “modern” webpages use client-side JavaScript to separately request the actual data from the web server through a REST/HTTP API. This kind of API is not possible to fully restrict, unless they want to require all users to log in for viewing the webpage.
      And yeah, if it’s built like that, then you’d want to make use of that REST API. You do not need to use JavaScript to call it. Using any HTTP client library in any programming language, or even just curl, should work just as much.

      To see, if it’s built like that, open the “Network” tab in the Developer Tools of your browser and refresh the webpage.
      If it just loads a bunch of HTML, CSS and image files, then it’s the static webpage kind. If it sends/receives messages with JSON in the body to URLs without a file-type, then it’s likely the REST-API-kind.