openlayers/ol3 — pull request #2347 by tschaub (2014-07-12 03:58:28+00:00)
Title: Fix the export map example

As @barbalex discovered, the map needs to be rendered synchronously for the export map example to work.

While it is nice to have a justification for synchronous map rendering, I'll point out that it really shouldn't be necessary to re-render the map in this example. Ideally, a click would just grab the pixels that are already rendered. So I don't think that this is a solid justification for synchronous map rendering. But this would involve exposing the map canvas in a different way (not just in a render event). If we didn't have a `renderSync` method and didn't want to expose another method for getting the map canvas, we still could make this example work by rendering asynchronously, creating a new (hidden) anchor element on the first `postcompose`, setting its `href` to the rendered data, and invoking its `click` method. But this would make for some pretty ugly example code.

Anyway, nice fix @barbalex (can you tell there is some history here?).