Wikipedia:Reference desk/Archives/Computing/2016 July 31

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July 31[edit]

How do you extract a table of contents from a "web 2.0" publisher?[edit]

I was looking at The Intercept and trying to figure out how to get the full list of articles they've published from the beginning. This turns out not to be very straightforward. They have some infinite scrolling script abomination that you can, in theory, just keep scrolling down and down and down and five hours from now you'd have the full list. But in the meanwhile, the browser would probably crash or something, and in the meanwhile, how would I put the list into a useful format? I'd just want to see the list of static URLs (and they do exist), by means of a simple script on some free site that would crawl back through the links using whatever JSON interface (I assume) the index lookups are stored in.

They have one main script in the body of the site as loaded, which (after a pass through jsbeautifier.org) contains various mentions of "fetch" that pertain to the process of getting new posts with a "slug", but I don't understand really what it's doing.

Also, there are a lot of really weird numbers and single-letter functions in this. I don't really know what I'm doing with this, but let's be clear: are they trying to make it hard to figure out their index system, or am I just clueless about how it works?

Also, at the other end: If you can manage to successfully cut and paste a huge block of infinitely scrolled web dreck out of your browser ... where can you PUT it to look at the content effectively? I mean, you could dump it in Notepad and get the text without any link information, or you could dump it in an Office clone and get something so weighed down with all the pictures and other HTML content that it would surely crash, or damn near crash, but is there some program you can dump it into that files and indexes the information in a way that you can go through conveniently? Or are there add-ons that extract every link on a web page and dump them into a text file? Etc.

Wnt (talk) 08:26, 31 July 2016 (UTC)[reply]

There should exist some kind of API. Ruslik_Zero 20:59, 31 July 2016 (UTC)[reply]
Why do you say that? That's up to whether they've provided one. They aren't obligated to. --71.110.8.102 (talk) 04:34, 1 August 2016 (UTC)[reply]
Well, given that the user gets the articles somehow, I think there had to be an API by definition, at least for the "application" of a user's browser running their script. Right? Wnt (talk) 13:15, 1 August 2016 (UTC)[reply]
Hmm, okay, I was thinking along the lines of an API explicitly intended for third-party use, like Mediawiki's. They presumably don't document the inner workings of their software anywhere, though from the posts below it looks like you might have figured it out. --71.110.8.102 (talk) 21:05, 1 August 2016 (UTC)[reply]
Some web crawler that executes Javascript should probably allow you to map out the whole site. That's how search engines do it. You may need to do a bit of coding to customize things for the site. The functions you mention could be intentionally obfuscated, or they may be minified to reduce download size. --71.110.8.102 (talk) 04:34, 1 August 2016 (UTC)[reply]
https://theintercept.com/wp-json/posts?type[]=post&type[]=squirrel&filter[posts_per_page]=1&filter[orderby]=post_date&filter[order]=DESC&page=1

Use curl like utility in shell script to run in loops, incrementing the last parameter and redirect the output to a file, then grep the url you are looking for. This is the API that Ruslik was talking about. 120.63.227.88 (talk) 12:20, 1 August 2016 (UTC)[reply]

That's great! But can you explain how you went about figuring out this answer? I felt like I could have been reverse engineering the thing for days and still not know how to get at the data I wanted! Wnt (talk) 13:13, 1 August 2016 (UTC)[reply]
Use your browser's developer tools, go to the "network" tab, and with that page open, scroll down, You'll see it make periodic GET requests to that URL, which receive the response in JSON format. -- Finlay McWalter··–·Talk 14:48, 1 August 2016 (UTC)[reply]
Thanks! This does indeed work when I tried it in the current Firefox. Clearly I need to go over these tools again... Wnt (talk) 18:13, 1 August 2016 (UTC)[reply]