Asking to get a sense of what other people are doing with their template logic…

The template code

I’m reading some third-party template code like this:

      <li :if={message.role == :function_call} class="...">
        ...
              <.icon_for_role role={message.role} />
       ...
      </li>
      <li :if={message.role != :function_call} class="...">
        ...
              <.icon_for_role role={message.role} />
        ...
            <.markdown :if={message.role == :assistant} text={message.content} />
            <span :if={message.role != :assistant} >
              ...
            </span>
        ...
      </li>

In more than one occasion there’s a tag with an :if attribute immediately followed by a sibling tag with another :if that is the negation of the previous condition.

I realized a casual search of the docs for :if (Search for terms beginning with colon (e.g. ":if") · Issue #1820 · elixir-lang/ex_doc · GitHub) doesn’t work, but nonetheless found Components and HEEx — Phoenix v1.8.8. Docs and local code searches suggest there’s only :if and :for, no :else.

I wonder what other people are doing for cases like that? Repeating+negating conditions feels error prone to me.

How I think it should be written

I think <%= if %> ... <% else %> ... <% end %> would be more appropriate for template code like above? Or even <%= case %> and <%= cond %> for the more general cases?

I know JS frameworks like Vue have <tag v-if="condition">...</tag><tag v-else>...</tag>, but would not propose making Heex have even more ways to accomplish things that are already possible with existing syntax

What do you normally do in cases like that?