How to properly use case statements in EEx (LiveView)

Have you tried something like:

<div>
  <div>
  <%= case @nav do
    :post -> "Post view goes here"
    :main -> "Main view goes here"
    :board -> "Board view goes here"
   end %>
  </div>
</div>

?

You should use a helper for this… and try to remove any logic from template.

<%= display_nav(@nav) %>

and in page_view.ex

def display_nav(:post) do
  content_tag(:div) do
    "whatever"
  end
end
# etc.

Yes, doing it this way results in an error “missing terminator: end for do”. It does not recognize the “end” when formatted this way.

The whole reason I’m using the template page_live.html.leex is so I don’t have 1000 lines of HTML inside my page_live.ex (with no coloring/syntax highlighting because the IDE considers it all “String”). Are you saying it’s better to cut the template down to a mere four lines of function calls and put everything else, front- and back-end, inside page_live.ex? What is the advantage of this? I’m still relatively new to Phoenix, so I’m sure there are things I’m overlooking.

It’s just good practice… and it’s not like You have to add file, the page_view.ex already exists and is done for this purpose.

I don’t have any file page_view.ex in my project. I used the “mix phx.new my_app --live” command for initial config.

If it is for live, there was a live_helpers.ex inside live… but for 1.5.7.

Anyway live view can also have its own set of helpers.

OK well if I see anything like that, I will consider it. But I still need to figure out proper EEx case statement syntax. It seems like it would be documented somewhere.

Weird, we do exactly this a lot. And @kokolegorille the issue with content_tag is that it isn’t really usable with live view. You can’t for example do live_component inside of it and have it work correctly.

        <%= case @event do  %>
        <% %{type: :research_status_changed, data: status_change} -> %>
           stuff

        <% %{type: :labeling, data: %{comment: comment, user: user}} = event -> %>
             stuff
        <% end %>

This is pulled straight out of our codebase.

Can you provide a reproduceable example?

Hey, I run into similar problems when starting with liveview. For me it was mostly my due to non clean, highly convoluted code… from my messing programming. Disclaimer: I am not proficient in any ways. And your code doesn’t look convoluted. But we just see a part of it

Spinning up a fresh non-ecto liveview it all worked with your code.

But when doing something like this I can reproduce your error:

  <%= case @nav   do%>
   <% nil  %>
   <% _ -> %>

unexpected operator ->. If you want to define multiple clauses, the first expression must use ->. Syntax error before: ‘->’

Yes, doing it this way results in an error “missing terminator: end for do”. It does not recognize the “end” when formatted this way.

I guess further analysis could maybe explain how this can be achieved too.

My approach is maybe to trivial to have a chance. But have you checked on which line the compiler hits the syntax error? And is there any “surrounding” code. Another case statement somewhere around?