A Weird Imagination

Working around a broken ad-block block

The problem#

Slashdot recently made a change to their ad code that made the site completely fail to load for me, showing the message

Failed to load website properly since html-load.com is blocked. Please allow html-load.com

and then blaming ad blocking:

This page could not be loaded properly due to incorrect / bad filtering rule(s) of adblockers in use. Please disable all adblockers to continue using the website. (click OK if you'd like to learn more)

I could see the page loaded just fine behind those messages, so it was obviously a lie. But the page continually reloaded if I tried to dismiss those pop-ups, so the site was unusable.

(Actually, this appears to have been disabled in the time it took me to write this blog post, so I guess this is no longer needed. Although it may be applicable to other websites using the same or similar mechanisms.)

The solution#

Install this user script. I have only tested it with Greasemonkey on Firefox so it require modification to work on other user script managers or browsers.

The details#

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Devlog: Folklife schedule user script (2 of 2): fighting React

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The problem#

Last time, I built a user script that could run on the Folklife 2024 schedule page1 and reorganize it so it would display the schedule as a grid. But it was brittle and awkward to use because it requiring careful ordering of the interactions with the page and reloading to view a different day's schedule.

The solution#

After failing to come up with an appropriate place to add an event handler, I gave up and took a different approach. I modified the script to work fine if it's run multiple times (and exit quickly if there's no work to do), even if the page is not in a valid state, and then simply set it to rerun every half second. Definitely a hack, but it worked.

Here's the final version of the user script and the Git repo showing the version history.

The details#

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Devlog: Folklife schedule user script (1 of 2): building the grid

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The problem#

The Folklife 2024 schedule page1 is a schedule grid: locations are along the x-axis and time is along the y-axis. Except it's not actually arranged as a grid: each column is just stacked in order with no correspondence to the other columns or the absolute times of the events. Glancing at the code, I noticed the schedule data was available in JSON format, so it should be pretty easy write a user script to display the schedule in a slightly different format.

But when I went to actually make the changes, I found the code is obfuscated React that turned out to be tricky to modify.

The solution#

I was able to write this user script (git repo), which changes the display from the columns of events to a schedule grid. It even works on Firefox mobile, although only if you explicitly request the desktop site.

The details#

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Monkey patching async functions in user scripts

The problem#

I was writing a user script where I wanted to be able to intercept the fetch() calls the web page made so my script could use the contents. I found a suggestion of simply reassigning window.fetch to my own function that internally called the real window.fetch while also doing whatever else I wanted. While it worked fine under Tampermonkey on Chromium, under Greasemonkey on Firefox, the script would just silently fail with no indication of why the code wasn't running.

(The script I was writing was this one for fixing the formatting on the Folklife 2024 schedule to reformat the schedule to display as a grid. I plan to write a devlog post on it in the future, but just writing about the most pernicious issue in this post.)

The solution#

The problem was that Firefox's security model special-cases function calls between web pages and extensions (and user scripts running inside Greasemonkey count as part of an extension for this purpose). And, furthermore, Promises can't pass the boundary, so you need to carefully define functions such that the implicit Promise created by declaring the function async lives on the right side of the boundary.

The following code combines all of that together to intercept fetch() on both Firefox and Chromium such that a userscript function intercept is called with the text of the response to every fetch():

const intercept = responseText => {
  // use responseText somehow ...
};

const w = window.wrappedJSObject;
if (w) {
  exportFunction(intercept, window,
                 { defineAs: "extIntercept" });
  w.eval("window.origFetch = window.fetch");

  w.eval(`window.fetch = ${async (...args) => {
    let [resource, config] = args;
    const response = await window.origFetch(resource,config);
    window.extIntercept(await response.clone().text())
    return response;
  }}`);
} else {
  const { fetch: origFetch } = window;

  window.fetch = async (...args) => {
    let [resource, config] = args;
    const response = await origFetch(resource, config);
    intercept(await response.clone().text());
    return response;
  };
}

The details#

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Change title based on visible section

The problem#

In the computer game Keep Talking and Nobody Explodes, the "bomb expert" players are looking at a fictional "bomb manual", often frantically searching for the right page. While the intention is for this document to be printed out—and physical paper makes it relatively easy to keep the headings at the top of each page visible—there is also a web version if you prefer to view it on a screen (or don't have access to a printer). Scrolling through the web version feels a lot more awkward than flipping through the paper version; one workaround I found was to open different pages in different browser tabs or windows, but then identifying which page is in which window is still awkward.

The solution#

I created a userscript, "BombManual.com Tab Title and TOC" that automatically updates the tab title to match the title of the currently visible page. It additionally adds a table of contents to make it easy to quickly open all of the pages in separate tabs or windows.

If you do not already have one, you will need to install a userscript manager extension for your browser to use it. Alternatively, you could bookmark this bookmarklet, but as you would have to click that bookmark on every instance of the page you opened, that's less convenient.

The details#

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User scripts on iPad

The problem#

Google Forms is a tool that allows for easily setting up simple structured data entry. But it's designed to make it easy to analyze a lot of data that has been entered, not to view a single entry. There is a view to show individual entries, but it's very cluttered due to including all of the options that were not selected as well as those that were selected. A display that showed only the entries that were selected could be used as a quick and dirty way to make a form letter-like website.

To make this problem harder, the solution has to run on iPad, a platform not exactly known for its user programmability.

The solution#

Bookmark this link: hide unselected items in Google Form. Then select that bookmark when on the appropriate Google Forms page. Note that in addition to hiding unselected entries, if the entry that is not select has a value of "Yes", then its entire section will be hidden. If you don't want that behavior, bookmark this variant of the script instead.

The details#

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