2009/4/8 Aude
<aude.wiki@gmail.com>
I would like to test if a user has JavaScript enabled, which can be done with an Ajax call or other way. If they don't, then don't load all the external JavaScript, so as to keep the code lightweight and fast. If the user does have JavaScript enabled, then load the map.js script.
If JavaScript is not enabled, the browser won't load scripts, no need to test for it.
As for where to have the OpenLayers code, I would like to have our own copy which we can keep up-to-date as possible. It would not be good to reference the OpenLayers.js directly from OpenLayers or OSM, since those will get changed as others see fit. It could be that some change will break our extension. When we do update our copy of OpenLayers.js, we can test it with our extension and make sure everything is okay.
The SlippyMap extension requires a small change to the original OpenLayers code. At the very end of the file, it sets a variable to "true", so that the JavaScript can be loaded asynchronously. The part of the JavaScript that creates the map polls for these variables. If they are not yet set, the function calls itself using alarm() and a ~0.5s delay. Without this hack, the loading of the page would stall at the map in many browsers when using slow links or slow CPUs
Regards,
jens