Elixir Language Templating Commenting

[Immortalin]

When something like this:

<%= form_for @changeset, @action, fn f -> %>
  <%= if @changeset.action do %>
    <div class="alert alert-danger">
      <p>Oops, something went wrong! Please check the errors below:</p>
      <ul>
        <%= for {attr, message} <- f.errors do %>
          <li><%= humanize(attr) %> <%= message %></li>
        <% end %>
      </ul>
    </div>
  <% end %>

  <div class="form-group">
    <%= submit "Submit", class: "btn btn-primary" %>
  </div>
<% end %>

is commented, you get this:

<!-- <%= form_for @changeset, @action, fn f -> %> -->
<!--   <%= if @changeset.action do %> -->
<!--     <div class="alert alert-danger"> -->
<!--       <p>Oops, something went wrong! Please check the errors below:</p> -->
<!--       <ul> -->
<!--         <%= for {attr, message} <- f.errors do %> -->
<!--           <li><%= humanize(attr) %> <%= message %></li> -->
<!--         <% end %> -->
<!--       </ul> -->
<!--     </div> -->
<!--   <% end %> -->

<!--   <div class="form-group"> -->
<!--     <%= submit "Submit", class: "btn btn-primary" %> -->
<!--   </div> -->
<!-- <% end %> -->

However, it doesn't actually comment out the templating tags as they have to be turned to the <%# %> form. One suggestion would be to keep the existing html style formatting as it helps the editor display things properly.

[redguardtoo]

what's your major-mode? web-mode?

[redguardtoo]

It's because web-mode does NOT define the comment operation for this language, a workaround:

(defalias 'web-mode-comment-elixir-block 'web-mode-comment-erb-block)
(defalias 'web-mode-uncomment-elixir-block 'web-mode-uncomment-erb-block)

You suggestion is interesting, let me think how to do it.

For now, I just notify the user which function web-mode not implemented yet.

[Immortalin]

@redguardtoo the problem is that elixir and EEx doesn't have any built-in block comments like ruby as most documentation is done via module attributes. Also, there are three types of tags:

Tags

EEx.SmartEngine supports the following tags:

<% Elixir expression - inline with output %>
<%= Elixir expression - replace with result %>
<%% EEx quotation - returns the contents inside %>
<%# Comments - they are discarded from source %>

This means implementing comments is not easy as you have to keep in memory what the previous type the tag was in before turning them into comments. An alternative would be to wrap the whole line within a comment tag and remove them later when need. Sort of like a paredit slurp and barf. This might be easier as you could probably borrow some code from smartparens or paredit etc. However, I am not sure whether this would affect the compiler in anyway and whether it would escape the templates within comments etc. I am not sure whether the elixir-vim or sublime text modules support commenting, maybe you can take a look at their source if they do.

[redguardtoo]

can you send me a a complete eex file? for the workaround, defalias to the ruby should work in all three cases.

This had better be resolved in web-mode, I could send a pull request to web-mode.

Just double check, is below code valid:

<%# Elixir expression - inline with output %>
<%#= Elixir expression - replace with result %>
<%#% EEx quotation - returns the contents inside %>

[Immortalin]

@redguardtoo the code snippet in the first post is a complete eex file. It is merged and compiled at runtime into a complete html file.

[Immortalin]

@redguardtoo the defalias solution works for single line comments but not multi-line ones

[redguardtoo]

I can see that, I will fix that this weekend

[Immortalin]

Thanks!

[redguardtoo]

770981c can comment/uncomment mixed code in web-mode (Chen Bin) v2.2

[Immortalin]

@redguardtoo thanks a ton! :D

[Immortalin]

@redguardtoo this fails for nested comments, e.g.:

  <script src="<%= static_path(@conn, "/js/en.js") %>"></script>

Commenting the above gives the following:

  <!-- <script src="<%= static_path(@conn, "/js/en.js") %>"></script> -->

The templating language in question is language agnostic i.e. it doesn't care whether you are using HTML, or YAML or JSON etc. it just does the templating.

[redguardtoo]

Just double check, so you want to only comment out the template language but keep the html, right?
That's doable. I can add a flag.

[Immortalin]

@redguardtoo actually, both. I am using comment-or-uncomment-lines but due to how the templating language parser works, it doesn't recognize the commented out HTML so there needs to be double commenting.

[redguardtoo]

got, interesting. I will see what I can do.

[redguardtoo]

upgrade to v2.3 then,

(setq evilnc-comment-both-snippet-html t)

[Immortalin]

@redguardtoo by the way, it fails for tags that span multilines e.g.

<h2>Edit trade</h2>

<%= render "form.html", changeset: @changeset,
                        action: trade_path(@conn, :update, @trade) %>

[Immortalin]

@redguardtoo and it also fails for multiple tags on one line e.g.

<li><%= humanize(attr) %> <%= message %></li>

[redguardtoo]

single line is fine, you need (setq evilnc-comment-both-snippet-html t) at first.

for the multiple line tag, I think it's doable but need more complicated algorithm. For now, even web-mode's own command M-x web-mode-comment-or-uncomment does not work.

[Immortalin]

@redguardtoo the single line fails when there's multiple EEx tags in-between the html tags

[redguardtoo]

Could you give me a sample file with multi-line and single line eex, and exact steps to reproduce the issue. and M-x evilnc-version to double check version.

[Immortalin]

@redguardtoo I am on 2.3 and the following is the example that fails:

<li><%= humanize(attr) %> <%= message %></li>

[redguardtoo]

For multi-line snippet, the best way is do it in web-mode. I will raise a issue to web-mode developer. (fxbois/web-mode#670)

For single line, it works on my computer, could you re-install evil-nerd-commenter?

C-h v evilnc-comment-both-snippet-html to double check at first.