James_E
I have the following utility template, for a list that is required to be rendered as a grid whenever CSS is enabled:
<%!-- grid_list.html.heex -->
<ul
class={[
"tw-grid",
"tw-grid-cols-#{Enum.count(@entries) |> :math.sqrt |> :math.ceil |> trunc}",
@class
]}
>
<li :for={entry <- @entries}>{render_slot(@inner_block, entry)}</li>
</ul>
<%!-- https://tailwindcss.com/docs/detecting-classes-in-source-files#dynamic-class-names
"tw-grid-cols-1"
"tw-grid-cols-2"
"tw-grid-cols-3"
"tw-grid-cols-4"
"tw-grid-cols-5"
"tw-grid-cols-6"
"tw-grid-cols-7"
"tw-grid-cols-8"
--%>
I invoke it, for example, as so:
<.grid_list :let={asset} entries={@state.assets} class="tw-p-1 tw-gap-1 sm:tw-p-4 sm:tw-gap-4">
<.asset asset={asset}/>
</.grid_list>
So my question is: is there any way for me to have the template automatically pass through any “extra” attributes, such as title, that I invoke it with? Or do I have to hardcode the “whitelist” of allowed passthrough attributes?
Where Next?
Trending in Questions
Other Trending Topics
Latest Phoenix Threads
Latest on Elixir Forum
Sponsor Spotlight
Build Elixir applications with speed and confidence.
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #library
- #deployment
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #elixirconf
- #channels
- #exunit
- #discussion
- #code-sync
- #podcasts
- #javascript
- #onsite
- #dialyzer
- #docker
- #authentication
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ai
- #ecto-query
- #elixirconf-us
- #blog-post
- #elixir-ls
- #phoenix_html
- #iex
- #graphql
- #genstage
- #websockets
- #supervisor
- #advent-of-code
- #distillery
- #processes
- #elixirconf-eu
- #api
- #forms
- #metaprogramming
- #hex
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Elixir, Erlang & BEAM conferences from Code Sync - join us in 2026!
Master modern tools, write cleaner code, and tackle real-world challenges.
**Building the future of software with AI, trust, and human connection.**
The deployment platform built for Elixir: PaaS ease, VPS control.
The team behind Membrane, Popcorn, LiveDebugger. Available for hire.
Courses that'll move you from confusion to "Aha, now I get it!"
Showing Posts 1 to 5- Show Best Posts
- Show All (oldest first)
- Show All (newest first)
garrison
You can use global attributes. There is a whitelist, but the default includes all HTML global attributes (
titleis one of those). You can explicitly whitelist others in theattrcall.frankdugan3
IMO, a better option is to just use a style tag:
James_E
Hmm, it looks like “key
:restnot found” is the result if I add a<... title="...">parameter to the invocation and a<... {@rest}>parameter inside the template.Putting
attr :rest, :globaljust beforeembed_templates "page_html/*"also leads to some incomprehensible compile-time errors on utility templates that used to be fine:Is there any way to configure
Phoenix.Component.attr/3within.heextemplates, or will I have to refactor this to use.ex/def (assigns)/~H?garrison
I think you do have to do this, yes. We’ll see if somebody corrects me.
Some people disable inline styles via CSP for security reasons. There are ways around this but they’re annoying.
steffend
When you want to use attr / slot with an external .heex file you need to define an empty function head in the .ex file that has embed_templates. There’s an example in the docs: Phoenix.Component — Phoenix LiveView v1.2.5