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

RobertKielty
My overall initial first impressions of this book are very good. I will document my local spacemacs setup to as I work through the book.
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
adamaiken89
Anyone is interested in a classical textbook for algorithms can go and check that.
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
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
Fl4m3Ph03n1x
Learning Domain-Driven Design Building software is harder than ever. As a developer, you not only have to chase ever-changing technologic...
New

Other popular topics Top

AstonJ
I’ve been hearing quite a lot of comments relating to the sound of a keyboard, with one of the most desirable of these called ‘thock’, he...
New
AstonJ
Thanks to @foxtrottwist’s and @Tomas’s posts in this thread: Poll: Which code editor do you use? I bought Onivim! :nerd_face: https://on...
New
PragmaticBookshelf
Build efficient applications that exploit the unique benefits of a pure functional language, learning from an engineer who uses Haskell t...
New
New
husaindevelop
Inside our android webview app, we are trying to paste the copied content from another app eg (notes) using navigator.clipboard.readtext ...
New
New
sir.laksmana_wenk
I’m able to do the “artistic” part of game-development; character designing/modeling, music, environment modeling, etc. However, I don’t...
New
PragmaticBookshelf
Get the comprehensive, insider information you need for Rails 8 with the new edition of this award-winning classic. Sam Ruby @rubys ...
New
PragmaticBookshelf
Explore the power of Ash Framework by modeling and building the domain for a real-world web application. Rebecca Le @sevenseacat and ...
New
mindriot
Ok, well here are some thoughts and opinions on some of the ergonomic keyboards I have, I guess like mini review of each that I use enoug...
New