ggarnier

ggarnier

Modern Asynchronous JavaScript: displaying images as they're loaded (page 50)

In Aborting Multiple Fetch Requests with One Signal section, the code in abort/abort_ex09.js doesn’t show the downloaded images until Promise.all fulfills, which means you need to wait for all the image downloads before seeing them. Also, if you cancel after some downloads have finished, you won’t see those images.

I suggest a small change to make it display the images as the corresponding promise fulfills:

33c33,38
<   const tasks = urls.map(url => fetch(url, {signal: controller.signal}));
---
>   const tasks = urls.map(url => fetch(url, {signal: controller.signal}).then(async (r) => {
>     const img = document.createElement('img');
>     const blob = await r.blob();
>     img.src = URL.createObjectURL(blob);
>     gallery.appendChild(img);
>   }));
36,43c41,43
<     const response = await Promise.all(tasks);
<     response.forEach(async (r) => {
<       const img = document.createElement('img');
<       const blob = await r.blob();
<       img.src = URL.createObjectURL(blob);
<       gallery.appendChild(img);
<     });
<     result.textContent = '';
---
>     Promise.all(tasks).then(() => {
>       result.textContent = '';
>     });

Marked As Solved

Faraz

Faraz

Author of Modern Asynchronous JavaScript

Oh, my bad! :grinning: Thanks for clarifying that. We’re updating the code in the next version of the book.

Where Next?

Popular Community topics Top

finner
As one of my New Year resolutions is to read more tech I’ve decided on an attempt to document my travels in Mannings Modern Java in Actio...
New
Tommy
So I have enough money to last a year. Realistically I’m still going to have to work part time painting. I’m so done with it though! I h...
New
mafinar
Crystal recently reached version 1. I had been following it for awhile but never got to really learn it. Most languages I picked up out o...
New
mafinar
TL;DR I am reading “Domain Modeling Made Functional” and discussing and keeping a journal of what I learned from it, any co-readers welco...
New
TwistingTwists
I have read first chapter. Will add my notes / code tries / self exploration as I go along! Thank you @AstonJ for encouraging to start ...
New
ohm
I would love to begin a book club with Mike Amundsen’s (@mamund) book Design and Build Great Web APIs. It seems that building new syste...
New
rgerardi
Hello all. Creating this space here for general discussion and chat about Powerful Command-Line Applications In Go In particular, we ca...
New
AstonJ
With Phoenix and LiveView having recently had a fairly major release, and Programming Phoenix LiveView being updated too, we thought it w...
New
PragmaticBookshelf
When the pandemic, heart disease, and personal tragedy threatened to steal everything the Tates spent years building, they found hope, he...
New
TomMahon
How did a sleepy valley become the epicenter of the technological world as we know it? In the 40th Anniversary Edition of my book, “Charg...
New

Other popular topics Top

DevotionGeo
I know that these benchmarks might not be the exact picture of real-world scenario, but still I expect a Rust web framework performing a ...
New
Exadra37
I am thinking in building or buy a desktop computer for programing, both professionally and on my free time, and my choice of OS is Linux...
New
PragmaticBookshelf
Design and develop sophisticated 2D games that are as much fun to make as they are to play. From particle effects and pathfinding to soci...
New
AstonJ
We have a thread about the keyboards we have, but what about nice keyboards we come across that we want? If you have seen any that look n...
New
AstonJ
I ended up cancelling my Moonlander order as I think it’s just going to be a bit too bulky for me. I think the Planck and the Preonic (o...
New
Margaret
Hello everyone! This thread is to tell you about what authors from The Pragmatic Bookshelf are writing on Medium.
1147 28379 760
New
Maartz
Hi folks, I don’t know if I saw this here but, here’s a new programming language, called Roc Reminds me a bit of Elm and thus Haskell. ...
New
Help
I am trying to crate a game for the Nintendo switch, I wanted to use Java as I am comfortable with that programming language. Can you use...
New
AstonJ
If you want a quick and easy way to block any website on your Mac using Little Snitch simply… File &gt; New Rule: And select Deny, O...
New
AstonJ
Curious what kind of results others are getting, I think actually prefer the 7B model to the 32B model, not only is it faster but the qua...
New