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

chasekaylee
Hi there everyone! Recently, I have fallen in love with programming with Elixir and have been having so much fun with it. I have been do...
New
wolf4earth
At work we plan to replace a totally overkill Kafka instance with a combination of SNS and SQS. I don’t want to get into a discussion on ...
New
s2k
I have this code in a file that’s used to … render templates. require 'erb' require 'ostruct' MISSING_CONFIG_MARKER = :config_key_and_v...
New
TwistingTwists
Hello Folks, I am a novice developer from India. Intending to learn Elixir and web apps (phoenix framework). What are things that I MUS...
New
Fl4m3Ph03n1x
Background I am now trying Gradual type checking, as a consequence I am giving a shot to Gradient. As I see it, this is an alternative to...
New
Fl4m3Ph03n1x
Background I am trying to up my Functional Programming (FP) skills and one of the things that newcomers first learn in FP is the Option T...
New
Fl4m3Ph03n1x
Background PS: the following situation describes an hypothetical scenario, where I own a company that sells things to customers. I have ...
New
Fl4m3Ph03n1x
Background I am moving towards defined data structures in my application, and I find that TypedStruct is quite useful. Questions Howeve...
New
New
pillaiindu
What is the difference between using :references and :belongs_to in the following command? bin/rails generate scaffold LineItem product:...
New

Other popular topics Top

AstonJ
Or looking forward to? :nerd_face:
502 14279 275
New
Rainer
My first contact with Erlang was about 2 years ago when I used RabbitMQ, which is written in Erlang, for my job. This made me curious and...
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
PragmaticBookshelf
Use WebRTC to build web applications that stream media and data in real time directly from one user to another, all in the browser. ...
New
PragmaticBookshelf
Programming Ruby is the most complete book on Ruby, covering both the language itself and the standard library as well as commonly used t...
New
First poster: bot
zig/http.zig at 7cf2cbb33ef34c1d211135f56d30fe23b6cacd42 · ziglang/zig. General-purpose programming language and toolchain for maintaini...
New
First poster: AstonJ
Jan | Rethink the Computer. Jan turns your computer into an AI machine by running LLMs locally on your computer. It’s a privacy-focus, l...
New
CommunityNews
A Brief Review of the Minisforum V3 AMD Tablet. Update: I have created an awesome-minisforum-v3 GitHub repository to list information fo...
New
NewsBot
Node.js v22.14.0 has been released. Link: Release 2025-02-11, Version 22.14.0 'Jod' (LTS), @aduh95 · nodejs/node · GitHub
New
PragmaticBookshelf
Fight complexity and reclaim the original spirit of agility by learning to simplify how you develop software. The result: a more humane a...
New