IFrame Seamless attribute should allow for disabling features

After reading the HTML5 specification on the seamless attribute of the 
iframe element, I believe the seamless attribute to be too narrowly 
considered.

It seems, the seamless attribute basically enables three features:

* automatic iframe height calculation
* CSS integration
* DOM integration

I see a problem in integrating the later two. So I would like to suggest the 
seamless attribute to become a comma separated list of above three Seamless 
properties to be enabled. For backward compatibility to HTML5, if the 
attribute value equals "seamless", all three properties should be enabled.


Here's my reason for this suggestion:

I'm using iframe elements to render micro parts of a web page, e. g. a data 
grid, without requiring much JavaScript ado. In the following I call these 
iframe micro page elements "controls".

In our web application I'm inserting arbitrary iframe controls into several 
web pages.

If the page's CSS would have influence on the iframe control's rendering, 
then it would be necessary to test each and every iframe control on each and 
every page where the iframe control could possibly be inserted (probably 
database driven), because some CSS on any particular page might have bad 
influence on the iframe control's content.

So I would prefer to just add an additional <link> element (the 
application's CSS) to the iframe control's HTML content and still be sure 
that there won't be any other CSS influencing the iframe control's HTML 
presentation.


Same for DOM integration: jQuery selectors may find elements not intended to 
be found if both, the page's and the iframe controls' DOM trees would be 
merged.

The current definition results in a testing hell, from my perspective.


So I suggest that any of the above three seamless features may be optionally 
applicable.

Possible seamless attribute values may be (just suggesting some names here):

    autoheight   =   sets the iframe's height to the minimum height 
necessary to omit a scrollbar
    cssinclude   =   have the page content's CSS being prepended to the 
iframe content's CSS
    dominclude   =   have the iframe content's DOM integrate with the page 
content's DOM
    seamless   =   "autoheight,cssinclude,dominclude"

attribute seamless = [ autoheight || cssinclude || dominclude ] | seamless

Regards,
Axel Dahmen

Received on Monday, 14 April 2014 14:30:41 UTC