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

pillaiindu
Cross posting from HashNode. A friend of mine is creating Uber-like app for a small company with 200 to 1000 cars. The app will operate ...
New
Kurisu
Hello and happy new year! I would like to buy a Ruby On Rails ebook for learning purpose. What would be the ROR equivalent of “Programm...
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 trying to encode a structure into json format using the Jason library. However, this is not working as expected. Code L...
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 have a personal project that is an elixir desktop application for PC Windows. It works pretty well, but now I want to give i...
New
sona11
I’m having a difficulty. I want to modify an attribute’s data type from String to Array. { “id”: “trn:tarb:tradingpartner:uuid:00000...
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

Other popular topics Top

PragmaticBookshelf
Learn from the award-winning programming series that inspired the Elixir language, and go on a step-by-step journey through the most impo...
New
PragmaticBookshelf
Ruby, Io, Prolog, Scala, Erlang, Clojure, Haskell. With Seven Languages in Seven Weeks, by Bruce A. Tate, you’ll go beyond the syntax—and...
New
Exadra37
Please tell us what is your preferred monitor setup for programming(not gaming) and why you have chosen it. Does your monitor have eye p...
New
AstonJ
You might be thinking we should just ask who’s not using VSCode :joy: however there are some new additions in the space that might give V...
New
PragmaticBookshelf
Build highly interactive applications without ever leaving Elixir, the way the experts do. Let LiveView take care of performance, scalabi...
New
AstonJ
Biggest jackpot ever apparently! :upside_down_face: I don’t (usually) gamble/play the lottery, but working on a program to predict the...
New
PragmaticBookshelf
Author Spotlight: Peter Ullrich @PJUllrich Data is at the core of every business, but it is useless if nobody can access and analyze ...
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
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