Re: [whatwg] The <iframe> element and sandboxing ideas

On Wed, May 21, 2008 at 3:30 PM, Ian Hickson <> wrote:

>  * I've added a seamless="" boolean attribute to <iframe>, which, if
>   the content's active document's URI has the same origin as the
>   container, causes the iframe to size vertically to the bounding box
>   of the contents, and horizontally to the width of the container,
>   and which causes the initial containing block of the contents to be
>   treated as zero height. In addition, styles on the root element of
>   the content must inherit from the <iframe> instead of being the
>   initial values, and the style sheets that apply to the <iframe>
>   must also apply to the contents. In addition, any time the browsing
>   context navigates itself, the parent browsing context gets
>   navigated instead.

This looks awesome.

So, the whole point of these is defining elements that are isolated from
their surrounding context on different axes. Same origin iframes currently
just give you CSS isolation. sandbox affords script isolation. seamless
affords the ability to turn off the CSS isolation.

Seems to me that we need a third property which controls event isolation.
Currently events don't propagate in/out of iframes and event coordinates are
all relative to the iframe's viewport (e.g. on mouse events).

My first intuition was that seamless should also just propagate events and
have mouse coordinate be relative to the parent browsing context. But I can
think of cases where you would want to control the two separately. For
example, if you are especially concerned about performance and don't want
events in the parent browsing context to be handled by the iframe's


Received on Saturday, 24 May 2008 17:56:22 UTC