mrmurphy

mrmurphy

How exactly does phx-update detect changes?

I’ve run into a situation where I’ve got a list of posts inside of a container that uses phx-update=“prepend”, and the posts on the socket are temporary assigns. Inside of the “for” comprehension, I want to render data not only from the post, but from another assign on the socket.

When the post changes, my DOM updates render, but when the other assign I’m using (pending_loves, in the image) changes, I don’t get any DOM updates. I’m guessing this is because live view is doing some magic change tracking around the for comprehension specifically? What’s the most idiomatic way to inform Live View that I want the content inside of the for to update when a different assign changes as well?

Most Liked

mrmurphy

mrmurphy

Thanks! Victor Mono:

dimitarvp

dimitarvp

Thank you! Instant switch in my terminal programs. Can’t believe I missed it even though I have it in my library.

Previously used InconsolataGo but Victor Mono is definitely better. :slight_smile:

mrmurphy

mrmurphy

I thought maybe if I included the pending_loves assign on the right-hand side of the for comprehension, the change would be picked up and re-rendered. But no dice:

  <div id="posts" class="max-w-lg mx-auto dark:bg-gray-800" phx-update="prepend">
    <%= for {post, pending_loves} <- (@posts|>Enum.map(&({&1, get_pending_loves(@pending_loves, &1.id)}))) do %>
    <div id="<%= post.id %>">

Even with this change, when I update the assign @pending_loves, the count of pending loves does not update on the page inside of the for comprehension until the post object is updated. It does update if placed outside of the comprehension, though, even inside of the phx-update="prepend" container.

Where Next?

Popular Backend topics Top

Rainer
Is there somewhere a good introduction to rust for experienced programmers (with years of C++/C#/Java experience)? Wanted to give it a t...
New
andrea
Can Phoenix LiveView be used in multi-page applications, unlike React/Vue/Blazor which seems to be targeted for SPA?
New
Fl4m3Ph03n1x
Background I am trying to encode a structure into json format using the Jason library. However, this is not working as expected. Code L...
New
jeya
Dear Geeks I am new to pytest. I am following a youtube channel. I am writing the same code. learning to test login functionality of an...
New
GermaVinsmoke
Does anyone know beginner friendly Elixir/Phoenix Open source projects? For learning purpose :slightly_smiling_face:
New
Ora2pgnewbie
Wanted to check if there is a UI available to use Ora2pg tool.
New
Manish_bose
Can anyone help me how to convert a long data to wide data in SQL without using hard coding? Regards Manish
New
sona11
I wrote this code to calculate Fibonacci numbers by specifying the size. The results are correct, however the one thing that concerns me ...
New
harwind
I received this error for a binary search programme in C, despite the fact that it requested for inputs and produced the right output. Th...
/c
New
Fl4m3Ph03n1x
Background I have a phoenix application in Windows 11. Unfortunately for me, I cannot compile the application because of a dependency err...
New

Other popular topics Top

PragmaticBookshelf
Take your Go skills to the next level by learning how to design, develop, and deploy a distributed service. Start from the bare essential...
New
New
dasdom
No chair. I have a standing desk. This post was split into a dedicated thread from our thread about chairs :slight_smile:
New
AstonJ
There’s a whole world of custom keycaps out there that I didn’t know existed! Check out all of our Keycaps threads here: https://forum....
New
New
PragmaticBookshelf
Build highly interactive applications without ever leaving Elixir, the way the experts do. Let LiveView take care of performance, scalabi...
New
PragmaticBookshelf
Create efficient, elegant software tests in pytest, Python's most powerful testing framework. Brian Okken @brianokken Edited by Kat...
New
PragmaticBookshelf
Author Spotlight Jamis Buck @jamis This month, we have the pleasure of spotlighting author Jamis Buck, who has written Mazes for Prog...
New
PragmaticBookshelf
Build modern server-driven web applications using htmx. Whatever programming language you use, you’ll write less (and cleaner) code. ...
New
AstonJ
This is cool! DEEPSEEK-V3 ON M4 MAC: BLAZING FAST INFERENCE ON APPLE SILICON We just witnessed something incredible: the largest open-s...
New