Introduction

We developed cutomized Firefox supporting SVG Tiling & Layering with our partner in order to evaluate the possibility of implementation. And also, we also tried to contribute two parts of our codes to Firefox community through this development.

Implementation Proposal for SVG iframe element (A few codes landed in moz-central.)
Implementation Proposal for 'clipped' option of SVG 2 getBBox method (Just FYI. Basically, all codes landed in moz-central.)

Basically, the "iframe" element was implemented based on current SVG 2 WD [1] [2].

Feedback from communities

There are some feedbacks about our implementation and the current spec for "iframe" from Firefox community and SVG community [3][4][5][6].

In our understanding, they pointed out the followings.

The current spec causes multiple inheritance of "SVGElement" and "HTMLElement", and it would cause weird behaviours.
Duplicating a part of codes from "HTMLIFrameElement" to "SVGIFrameElement" is also undesirable because it complicates code maintenance.
Only really necessary stuffs for SVG is added to HTMLIFrameElement.

The gaps between "SVGIFrameElement" and "HTMLIFrameElement" are summarized in [7].

Discussion Point

It is difficult to progress the development of SVG "iframe" any more at least on the communities, until the direction of WG will be determined. This issue should be resolved for the other elements rather than only for "iframe", and it would not be resolved without progressing the comprehensive alignment between SVG and HTML.

Is there a big-picture solution for this issue?

Notes of customization points

Support iframe element (Non-standard)
lazyload attribute for Dynamic Loading (Non-standard)
- Refer to Resource Priorities ED (by Web Perf. WG)
min/max-zoom property for Level of Detail (Non-standard)
- Extend CSS3 Media Queries Rec and Media Queries Level 4 FPWD