<div {%{selected: index == 1}}><%= index %></div>

, else: []

fixes it. thanks guys.

the shortest I found (by accident) is:

<div boolean_attr={@one == 1}>boolean_attr</div>

I’d like a list of heex-recepies.
Here are some (including stupid ones):

<div {@dynamic_attr}>dynamic_attr from assign</div>
<div {@dynamic_attr} static_attr="is-static">dynamic_attr with static attribute</div>
<div boolean_attr={@one == 1}>boolean_attr</div>
<div {%{boolean_attr: @one == 1}}>boolean_attr from dict</div>
<div {if @one == 1, do: [boolean_attr: ""], else: []}>boolean_attr kw-list from if</div>
<div {if @one == 1, do: %{boolean_attr: ""}, else: %{}}>boolean_attr dict from if</div>
<div some_attr={if @one == 1, do: "one-is-one"}>value from if</div>
<div some_attr={if @one == 0, do: "one-is-zero", else: "one-is-one"}>value from if/else</div>
<div class={"some_class #{if(@one == 1, do: " optional_class", else: "")}"}>interpolation</div>
<div class={"some_class" <> if @one == 1, do: " optional_class", else: ""}>concatenation 1</div>
<div class={"some_class" <> if @one == 0, do: " optional_class", else: ""}>concatenation 2</div>
<div {heex_helper(@some_state)}>dynamic_attr from helper function</div>
<div case={
      case @one do
        1 -> "one-is-one"
        _ -> "one-is-not-one"
      end
      }>
  case
</div>

I haven’t used HEEx yet but shouldn’t this
<div {if 1 == index, do: [selected: ""]} ><%= index %></div>
be
<div {if 1 == index, do: [selected: ""], else: []} ><%= index %></div>

From here it says it should be keyword list or map Views and templates — Phoenix v1.6.0 because you don’t have else returning [] it’s neither.

It would be nice if it supported nil as well.