---
# this is an empty front matter
---
{% include header.html %}
<p>
 Let's say ClearPress doesn't support our favourite format
 out-of-the-box. YAML for example - pretty common really but it hasn't
 (yet) been included as a standard response for views. We want to add
 YAML output using ClearPress' standard method naming (read_yml,
 list_yml etc.)  and tidy file extensions (.yml), just like we do for
 XML.
</p>

<p>
First in your view subclass, set any aspects ending in _yml to serve content in text/plain.

<pre><code>sub init {
  my $aspect = $self-&gt;aspect;

  $self-&gt;{content_type} ||= ($aspect =~ /_yml$/smx)?'text/plain':q[];

  return 1;
}
</code></pre></p>

<p>
Next, again in the view subclass, disable page decoration for aspects ending in _yml.

<pre><code>sub decor {
  my $self   = shift;
  my $aspect = $self-&gt;aspect;

  if($aspect =~ /_yml$/smx) {
   return 0;
  }
  return $self-&gt;SUPER::decor();
}
</code></pre></p>

<p>
Set up a template, data/templates/read_something_yml.tt2,  to use <a href="http://search.cpan.org/~rclamp/Template-Plugin-YAML">Template::Plugin::YAML</a>.

<pre><code>[%- USE YAML %]
[% yaml.dump(model) %]
</code></pre>

Note that as this stands it will dump the model's data and a lot of other junk from the template engine and the database handle etc.
</p>

<p>
So far what we've set up will allow us to access URLs like http://example.com/application/something/id;read_yml but that's pretty ugly, so last but not least we want to allow access via clean URLs like http://example.com/application/something/id.yml so in controller.pm we do:
<pre><code>sub accept_extensions {
  my $self = shift;
  return [
          @{$self-&gt;SUPER::accept_extensions},
          {'.yml'  =&gt; q[_yml]},
         ];
}</code></pre></p>

<p>
 Et voila! A YAML-formatted object dump with clean URL formatting. For extra credit you can make a clean data structure to dump using something like this:

<pre><code>[%- USE YAML %]
[%- PERL %]
  $stash->{clean} = {
    map { $_ => $stash->{model}->$_() }
    $stash->{model}->fields()
  }
[% END %]
[%- YAML.dump(clean) %]
</code></pre></p>

{% include footer.html %}