As I was working on implementing a test of this concept, I was wondering what happens in old browsers where the communication between the iframe and the page won't work. Are the advertisers supposed to check for this and know not to serve an expandable ad? If so, does anyone know if they do.
Princ S/W Eng
There is a placeholder for proxy communication support in older browsers. At the moment older browser support is not implemented in the reference implementation. The reasoning is that this represents such a thin and diminishing slice of the market that we didn't want to add the weight and complexity to the ref impl. I'd be interested to hear what slice of your overall traffic this represents. Depending on this feedback we might revisit this decision, or look at a community patch to add this support.
In the short term I'd recommend having the server detect the older browser and use an alternate method to safe frame in cases where expansion and communication is required.
Again agree with Chris here. I should also mention that while we do have the ability to do this (without flash), in the older browser case, it's a bit hacky b/c of all the hoops you have to jump through and while i'm pretty confident in it being secure there is always a chance it could open a hole. . .
If you're really in a bind, sure we can revist this.. .we may want to take this offline as well amongst ourselves.