How to change Mojolicious Lite default error not found to a custom json response

Question

I'm creating a json web service using Mojolicious Lite.

By default Mojolicious returns a HTML response for a server error or not found error.

Is there a way to overwrite this to a custom JSON response?

Answer 1

Here are two approaches:

1. Use json as the app's default format and use a not_found.*.json.ep template

   use Mojolicious::Lite;
   app->renderer->default_format('json');
   app->start;
   __DATA__
   
   @@ not_found.development.json.ep
   {"not":"found","code":404,"data":{"key1":"value1","key2":[42,19,"value3"]}}
   

2. Override json payload with a before_render hook.

   use Mojolicious::Lite;
   hook before_render => sub {
       my ($c,$args) = @_;
       if ($args->{template} && $args->{template} eq 'not_found') {
           $args->{json} = { "too bad" => "so sad" };
       }
   };
   app->start;