Inert scripts not running for custom elements when loaded via <link rel="import">

[DirectXMan12]

When you have an element like this

<element name="x-cheese">
  <template>
    <script>
      alert('hi');
    </script>
  </template>
</element>

The script in the template is inert, and should run when the template is inserted as ShadowDOM into any <x-cheese> element. However, this only occurs when the elements are declared inline; when the elements are imported via <link rel="import">, the inert script does not get activated.

Browser: Chromium 28.0.1496.0 (Developer Build 197749)
OS: Linux
Blink: 537.36 (Unknown URL@0)
JavaScript: V8 3.18.5.2

Experimental features enabled (e.g. native ShadowDOM, etc)

[sjmiles]

I'm not sure this is really going to be supported. There is after all an elaborate mechanism for attaching code to the instancing of a custom element (which has evolved to avoid all kinds of messy problems). In any case, if it doesn't work under native ShadowDOM and you think it should, you may have to file a bug here: https://www.w3.org/Bugs/Public/showdependencytree.cgi?id=14978

[sorvell]

This is due to the way HTMLImports is polyfilled. Imports are retrieved, a new document is made, and the html for that document is set via innerHTML. For security reasons, script nodes generated in this way do not execute. The native implementation of HTMLImports should run these scripts.

Unless there's a compelling reason, we do not plan to correct this behavior.