table_for with no items displays "[]"

[djwonk]

In a show page for one object, where a table_for is used to display associated items, it displays "[]" instead of just making an empty table.

Source code example, in my cases.rb file:

ActiveAdmin.register Case do

# ...

panel "Notes" do
  table_for(c.case_notes) do |t|
    t.column("Note ID", :id) do |case_note|
      link_to(case_note.pretty_id, admin_case_note_path(case_note))
    end
    t.column("Contact ID") do |case_note|
      contact = case_note.contact
      if contact
        link_to(contact.pretty_id, admin_contact_path(contact))
      else
        "n/a"
      end
    end
    # ...

[djwonk]

The associated html is:

       <div class="panel">
          <h3>Notes</h3>
          <div class="panel_contents">
            <table border="0" cellspacing="0" cellpadding="0">
              <thead>
                <tr>
                  <th class="">Note ID</th>
                  <th class="">Contact ID</th>
                  <th class="">CSR</th>
                  <th class="note">Note</th>
                </tr>
              </thead>
              <tbody>[]</tbody>
            </table>
          </div>
        </div>

[djwonk]

I hacked out the offending stray text using jQuery:

$(document).ready(function() {
  var panel = $('div.panel_contents');
  panel.each(function(index) {
    var contents = $(this).contents();
    var shady = $(contents[0]);
    shady.detach();
  });
});

[gregbell]

What version of active admin are you using? I can't seem to replicate it on master.

[pwightman]

For what it's worth, I'm experiencing this same issue on 0.3.4: http://cl.ly/1G151a2W2B1m3W0W0v0h

[djwonk]

I'm using 0.4.0.

On Tue, Feb 14, 2012 at 5:18 PM, Greg Bell
reply@reply.github.com
wrote:

What version of active admin are you using? I can't seem to replicate it on master.

---

Reply to this email directly or view it on GitHub:
#1016 (comment)

[djwonk]

I tried setting my Gemfile to point to the github version of activeadmin. This didn't solve the problem.

Can you point me to the code that I should examine more closely? I don't mind digging in, but a few pointers would help.

[latortuga]

@djwonk I tried looking into this a bit and couldn't figure it out on first walkthrough. The code in question can be found here https://github.com/gregbell/active_admin/blob/master/lib/active_admin/views/components/table_for.rb

You also might want to look in the arbre directory as that's where the HTML is mainly generated (https://github.com/gregbell/active_admin/tree/master/lib/active_admin/arbre)

My suspicion is that it has to do with default return values from some of the functions as otherwise why would a blank array show up? As an initial idea, perhaps the call to build_table should not be performed if the collection is empty.

I've had this problem on 0.3.4 and 0.4.0.

[pcreux]

This happens on ruby 1.9 only because [].to_s returns "[]" on 1.9.

[jancel]

This is fixed in master. Slated for 0.4.2.

[djwonk]

Thanks for fixing this!

I just want to mention that the behavior difference isn't just for []. It applies to all arrays.

In Ruby 1.8.7:

[1,2,3].to_s #=> "123"

In Ruby 1.9.3:

[1,2,3].to_s #=> "[1, 2, 3]"

Hopefully the code takes this into account.

[jancel]

Change only affects empty arrays. Arrays should work the same as they always have.

[pcreux]

Closed by 2d70197