[Widget] Support background images

[wuyongfeng]

Page, the Header, Footer have been achieved, other div inherit the "Background"

[zhizhangchen]

It's better to use htmlAttribute mapping to achieve this functionality, although htmlAttribute may have to be extended.

[wuyongfeng]

This difference in the IMAGE WIDGET for can not be used

[wuyongfeng]

This difference in the IMAGE WIDGET for can not be used

[sbryan]

in-line styles are "BAD"... absolutely not something we want to be promoting or encouraging developers to use or depend on.

While I'll accept this commit for initial implimentation, we REALLY need to move towards creating and maintaining a custom per-application CSS mapping that we generate during serialize steps, like for layout, code and live views, as well as on export. Then, these additional style attributes become available to be changed via CSS editing rather than adding more and more properties directly to the widgets.

[zhizhangchen]

Yes, in the long run, we should do that.

[sbryan]

Why only available on Page, Header and Footer widgets? It would not be unreasonable to allow image backgrounds on ALL widgets by default, and only exclude it for the exceptions (when we find them). Then we don't need to introduce a new widget class, just enhance Base, right?

[zhizhangchen]

The current inheritence mechanism doesn't allow the excluding of properties in base widget from extended widget. From Object oriented point of view, we shouldn't do that actually.

[sbryan]

On Mon, Jun 25, 2012 at 8:45 PM, Chen, Zhang Z
reply@reply.github.com
wrote:

The current inheritence mechanism doesn't allow the excluding of properties in base widget from extended widget. From Object oriented point of view, we shouldn't do that actually.

I don't think this is true from OO perspective. OO simply means
sub-class is descended from parent class, containing all the
properties and methods, with some additions, but ALSO allows for
default values to be overridden or methods to be replaced with it's
own versions.