Excel/Word Macro using a WebBrowser object in a Form (old IE did this nicely; Haven't done that since Edge came out.)
> can you write a web scraper in your browser? The answer is: YES, you can! So why is nobody doing it?
Completely agree with this sentiment.
I just spent the last couple of months developing a chrome extension, but recently also did an unrleated web scraping project where I looked into all the common tools like beautiful soup, selenium, playwright, pupeteer, etc, etc.
All of these tools were needlessly complicated and I was having a ton of trouble with sites that required authentication. I then realized it would be way easier to write some javascript and paste it in my browser to do the scraping. Worked like a charm!
You might like Tamper monkey. You can add a button to kick it off or whatever your heart desires.
Tampermoney also works around CORs issues with relative ease.
Userscripts for the win. Consider Violentmonkey over Tampermonkey though.
> Consider Violentmonkey over Tampermonkey though.
Why?
I wrote a prototype of a browser extension that scraped your bookmarks + 1 degree, and indexed everything into an in-memory search index (which gets persisted in localstorage). I took over the new tab page with a simple search UI, with instant type-ahead search.
Rough aspects:
a) It requires a _lot_ of browser permissions to install the extension, and I figured the audience who might be interested in their own search index would likely be put off by intrusive perms.
b) Loading the search index from localstorage on browser startup took 10-15s with a moderate number of sites; not great. Maybe would be a fit for pouchdb or something else that makes IndexedDB tolerable. (Or wasm sqllite, if it's mature enough.)
c) A lot of sites didn't like being scraped (even with rate limiting and back-off), and I ended up being served an annoying number of captchas in my regular everyday browsing.
d) Some walled garden sites seem completely unscrapable (even in the browser) - e.g. Linkedin.
In my experience building a browser-based scraper I preferred scraping pages by a direct in-browser visit rather that a fetch request. A direct visit from a real browser is basically undetectable by anti-bot software (unless you try to do something funny like automated deep crawling and scraping). So applied to your usecase it would have to go through every bookmark + 1 degree to index it. Maybe even in an offscreen canvas (haven't tried that though, could be detectable).
>Some walled garden sites seem completely unscrapable
Any examples besides Linkedin? Tell me what sites you're trying to target and I'll have a look to see what can be done with them. It takes some pretty evil Javascript obfuscation to block me and only one site has been able to do that. I doubt that the sites you're hitting are anywhere near that evil, lol. I would appreciate it if you have a good example that I could use in a future article.
How often did it crawl? Once per day shouldn't trigger any blockers.
> can you write a web scraper in your browser? The answer is: YES, you can! So why is nobody doing it?
My guess would be that some companies are doing it (I worked at a major tech company that is/was), just not publicizing this fact as crawling/scraping is such a gray legal area.
There is an extension called "Amazon Order History Reporter" that will scrape Amazon to download your order history. I've used it a couple times and it works brilliantly.
Why do you need a proxy or to worry about CORS? Why not just point your browser to rumble.com and start from there?
I've posted here about scraping for example HN with JavaScript. It's certainly not a new idea.
> Why do you need a proxy or to worry about CORS?
> Why not just point your browser to rumble.com and start from there?
Source: work at a startup that does a lot of scraping and these are issues we've run into. Our entire office network is blocked from some sites due to some early testing without a proxy.
I love it when something like this reminds me of a project from forever ago...
I also did something similar for my spring project. The idea was to buy a used car and I was frustrated with the BS the listing sites claimed as fair price etc..
I went the browser extension route and used grease monkey to inject custom JavaScript. I patched the window.fetch and because it was a react page it did most of the work for me providing me with a slightly convolute JSON doc everytime I scrolled. Getting the data extracted was only a question of getting a flask API with correct CORS settings running.
Thanks for posting using a local proxy for even more control could be helpful in the future.
I've read through that (hard to read, because of the bad formatting) but I still don't understand why you would do that instead of Playwright, Puppeteer etc. - The only reason seems to be "This technique certainly has its limits.".
>bad formatting
If you can elaborate, I would very much appreciate it. I'm always interested in doing better.
Why use Puppeteer etc. when you don't have to? What is the argument for using these additional tools versus not using them?
You don't have max-width set on the text, so unless you have your browser window resized to very small size the paragraphs will span your whole screen.
Which places you, the reader, fully in control of the width of lines you prefer to see. Adjust your browser window width, or apply a user style sheet to tell your browser to format the text the way you want to see it formatted.
I knew this reply would come... How many people do you think use custom browser stylesheets? It's probably smaller than 0.1% of the internet population and everyone moved on to formatting text so everyone can enjoy good readability. Also not all devices have the luxury of supporting custom stylesheets.
Of course it's always up to the site owner, but most people want people to read what they share.
I see. I don't have a wide-screen monitor (still using an old tube type until it finally expires but it's taking a few decades, lol). I've wondered whether people actually like reading websites on wide-screen. Some do and some don't. What would you suggest for a max width?
You could also try zooming in. My apps don't expand to full width because of the video box but you can zoom.
There's a lot of info about this but usually 500-700px or ~80 characters will be much easier to read: https://ux.stackexchange.com/questions/108801/what-is-the-be...
I have the opposite problem. I typically have many browser windows open at the same time but only two screens, and many sites that I use are designed to assume that everyone has full-screen browsers.
The red text on a yellow background is not great. Neither is a serif font. Also it should be JavaScript with a capital S.
Red text on yellow - you mean the website? Would you like the text to be darker?
And Beautiful Soup should be BeautifulSoup. Who makes the rules?
Yes, the website. Better contrast is good. Black on white works great.
Margins would also be nice on the left and right.
Beautiful Soup is two words. Just look at their website.
Too much contrast makes it hard to read too. (With bonus eye strain.)
Is there a happy in-between? Maybe not. What looks perfect to one user might appear atrocious to another. What is a poor website operator to do???
I dislike black-on-white and don't understand gray-on-black which seems to be popular now due to gamma settings being cranked up to 11 or something. I try to use some color as an in-between but that may take some time to "perfect".
Even Google Chrome's Lighthouse said that your background and foreground colors do not have a sufficient contrast ratio.
Every dark mode site in existence should fail that test.
Solutions that want to automate in the context of their customers' browser. For example, ListPerfectly, a solution for cross-listing to eBay, Poshmark, etc, does this in their browser extension.
This is just regular browser extension behavior though, a bit different than the use case talked about in this post.
In my web-scraping I've gravitated towards the "cheerio" library for javascript.
I kind of don't want to use DOMParser because it's browser-only... my web-scrapers have to evolve every few years as the underlying web pages change, so I really want CI tests, so it's easiest to have something that works in node.
I've been playing around with this idea lately as well! There are a lot of web interfaces that are hostile to scraping, and I see no reason why we shouldn't be able to use the data we have access to for our own purposes. CUSTOMIZE YOUR INTERFACES
Neo already did that in the Matrix:
is there anything that runs on WASM for scraping? the issue is that you need to enable flags and turn off other security features to scrape on your web browser and this is why its not popular but with WASM that might change
WASM runs in a sandbox. It can only talk to the outside world via Javascript so you can forget the idea that it might be a way to crack through browser security.
Maybe somebody will make a web browser with all of the security locks disabled. Sort of like the Russian commander in "Hunting for Red October" who disabled his missiles' security features in order to more effectively target the American sub but then got blown up by his own missile.
> You can find plenty of tutorials on the Internet about the art of web scraping... and the first things you will learn about are Python and Beautiful Soup. There is no tutorial on web scraping with Javascript in a web browser...
Um... [0]
Rather long so I'll read it later. Thanks for the tip. Got more or is that it?
Not that I know of, I'm just quipping a bit about my own work lol