HAML special case indentation with if statements

Question

So I have the following haml code:

.row
    .col-sm-12
        %h2
            = @title
        %h3 This Week
        %table
            %tr
                %td
                    %strong Date
                %td
                    %strong
                        = @available__or_tutor
            - 7.times do |i|
                %tr
                    %td{:rowspan => 3}
                        = @date = @date + 1.days
                - @available_times.each do |available_time, index|
                    - if i == available_time.day
                        - if index == 0 
                            %td
                                = @tutor_var
                                %img{:src => "/assets/tick.png", :style => "width: 30%;"}
                    - else
                    %tr
                        %td
                    %tr
                        %td

and I would like the final

%tr
    %td
%tr
    %rd

To be nested within the else statement. Specifically, they should line up with the tr just below 7.times do |i| because of the way haml forces indentation I can't seem to do this. I was wondering if HAML had some kind of override to permit some kind of backwards indentation. If that makes sense.

The less desirable solution is of course to add a partial in html/erb and just dump haml for that bit.

struthersneil struthersneil · Accepted Answer · 2013-10-29T00:13:49

Usually if something you want to do is impossible to do in HAML, it just means you need to consider an alternate approach. I'll try to interpret your problem and you can tell me if I'm miles away.

You want to iterate from 0 to 6.
You want to make a group of rows for each day based on @date. First you output a header row containing the date.
Then you want to find an entry in @available_times for that day. Note, the first problem I see--this logic is indented at the same level as the %tr above, so any %td elements output as a result of this logic would have no surrounding %tr. I'm going to assume you meant to output a %tr here, surrounding the %td.
Judging by your question, this next part is where the confusion begins. I think that you want to output two blank rows if no appropriate entry is found in @available_times. But there's no way to suddenly backtrack out of the hierarchy.

So here's my suggestion. You need to decide first if you have an entry in @available_times or not, and branch at the correct point, e.g.

- 7.times do |i|
    %tr
        %td{rowspan: 3}= @date = @date + 1.days
    - if @available_times.each_with_index.any? { |available_time, index | i == available_time.day && index == 0 }
        %tr
            %td
                = @tutor_var
                %img{src: "/assets/tick.png", style: "width: 30%;"}
  - else
      %tr
          %td
      %tr
          %td

Perhaps I've gone one guess too far and you really don't want a %tr within that if and you want the tutor cell to appear in the same row as %td{rowspan: 3} containing the date. If that's the case, you would perform the evaluation one level higher, e.g.

- 7.times do |i|
    - if @available_times.each_with_index.any? { |available_time, index | i == available_time.day && index == 0 }
        %tr
            %td{rowspan: 3}= @date = @date + 1.days
            %td
                = @tutor_var
                %img{src: "/assets/tick.png", style: "width: 30%;"}
    - else
        %tr
            %td
        %tr
            %td

Note, that evaluation as it stands can be shortened. As you're always checking for index == 0, you can just check the first entry in the list each time (is that what you meant? The logic will never pass for any entry on the @available_times list other than the first.)

if @available_times.first.day == i

Another note: you can also turn this:

  - else
      %tr
          %td
      %tr
          %td

Into this:

  - else 
      - 2.times do
          %tr
              %td

(Edit: I noticed you are using four spaces for indentation, I switched to use the same. I usually find I make less mistakes if I use two spaces, that's all.)

HAML special case indentation with if statements

1 Answers