using image assets in ember-cli-rails

big balls of mud killer
, in 05 July 2016

How do you use images from ember’s pipeline in rails? How do you use images from the asset pipeline in ember templates?

Even after reading this giant issue thread, I was still a bit unsure of how exactly to use an asset image in my ember template.

In my case I just wanted to use a single image in a .hbs template, so I had no access to rails asset helpers.

If you are using another solution such as ember-islands you may be able to simply use rails asset helpers.

I found a solution to use the prepend option in ember-cli-build. I prepended what I knew the output destination of the ember-cli-build to be.

ember-cli-build.js:

module.exports = function(defaults) {
  var app = new EmberApp(defaults, {
    fingerprint: {
      prepend: '/assets/ember-cli/apps/frontend/'
    }
  });
  return app.toTree();
};

Since I was using the ember_asset_tags helpers with a prepend option already, this was breaking there.

So I changed it to use the prepend option only if we are not in production (fingerprinting in ember cli only happens in rails production environment).

<!-- Your Ember app will be rendered here. -->
<div id="ember-application"></div>
<% if Rails.env.production? %>
  <%= include_ember_script_tags :frontend %>
  <%= include_ember_stylesheet_tags :frontend %>
<% else %>
  <% prepend = asset_url("/assets/ember-cli/apps/frontend/") %>
  <%= include_ember_script_tags :frontend, prepend: prepend %>
  <%= include_ember_stylesheet_tags :frontend, prepend: prepend %>
<% end %>

The ember-cli-rails team claims that they don’t plan to support this method of serving your ember app forever though. I wonder if I can accomplish the same using the supported mount_ember_app and render_ember_app helpers.

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