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

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
Concurrent Data Processing in Elixir is now content complete and I finally found the time I’ve been looking for to dedicate behind readin...
New
rustkas
To be a more productive reader when rereading a book, it is very convenient to create small rebar3 projects based on books’ samples and i...
New
TwistingTwists
This is my Journal for readings on Designing Elixir Systems with OTP. Will post chapter 01 tomorrow! Stay tuned!
New
RomanTurner
Agile Web Development with Rails 6 Chapter 11. Task F Currently reading and working through AWDR6 by Sam Ruby, David Bryant Copeland, a...
New
ggarnier
In Aborting Multiple Fetch Requests with One Signal section, the code in abort/abort_ex09.js doesn’t show the downloaded images until Pro...
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 Tailwind now the default CSS framework shipped with Phoenix we thought it would be nice to run this book club on the Elixir Forum. ...
New
AstonJ
With AI set to play a big role in our industry Elixir users are lucky to have Nx, so we’re running our Nx related book club on Genetic Al...
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

PragmaticBookshelf
Stop developing web apps with yesterday’s tools. Today, developers are increasingly adopting Clojure as a web-development platform. See f...
New
PragmaticBookshelf
Machine learning can be intimidating, with its reliance on math and algorithms that most programmers don't encounter in their regular wor...
New
ohm
Which, if any, games do you play? On what platform? I just bought (and completed) Minecraft Dungeons for my Nintendo Switch. Other than ...
New
PragmaticBookshelf
Rails 7 completely redefines what it means to produce fantastic user experiences and provides a way to achieve all the benefits of single...
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
New
PragmaticBookshelf
Leverage Elixir and the Nx ecosystem to build intelligent applications that solve real-world problems in computer vision, natural languag...
New
AstonJ
This is a very quick guide, you just need to: Download LM Studio: https://lmstudio.ai/ Click on search Type DeepSeek, then select the o...
New
RobertRichards
Hair Salon Games for Girls Fun Girls Hair Saloon game is mainly developed for kids. This game allows users to select virtual avatars to ...
New
PragmaticBookshelf
A concise guide to MySQL 9 database administration, covering fundamental concepts, techniques, and best practices. Neil Smyth MySQL...
New