TODO: full browser support

[ihadeed]

This PR was a good start to add some browser functionality. Running an app in browser (PWA, ionic serve ... etc) should do the following

• load images before setting background CSS property or src attribute (via XHR)
• use fallback image if loading failed

[marcosmfjunior]

hi, can u explain better how to do 1st step?

load images before setting background CSS property or src attribute (via XHR)

[ihadeed]

@marcosmfjunior
If the image host server sends browser-caching headers, then doing an XHR request (using Angular HTTP) will preload the image.

If we don't have cache headers, we need to create Image element and set it's src to that URL. The element doesn't have to be rendered in the DOM, just needs to exist in the memory.

[erperejildo]

I thought this was also working on browser. Makes sense now.
Anyway, I'll subscript for further info