From http://drupal.org/node/776028
From Klokan: (the creator of maptiler)
"I recommend to add into the Drupal OpenLayers code those two lines of
JavaScript code:// Do not display any warning for missing tiles
OpenLayers.Util.onImageLoadError =
function(){this.src='http://www.openlayers.org/api/img/blank.gif';}
OpenLayers.Tile.Image.useBlankTile=false;Better then http://www.openlayers.org/api/img/blank.gif would be to
use img/blank.gif on the local copy of OpenLayers. This will avoid
displaying of any artifacts for missing tiles in MapTiler layer."
So it does make sense to have a better-configurable approach to blank tile loading in OpenLayers. The default is to make a tile's background pink, which is pretty repulsive. But a much-simpler approach, advised by the MapTiler guy, also removes the logic in OpenLayers to retry tile requests - which is useful for layers in which there are multiple CNAMEs serving the same tileset, and tiles may load on one but not another at times.
Comments
Comment #1
tmcw CreditAttribution: tmcw commentedClosing. .olImageLoadError is defined in CSS, and other approaches are not generalized enough. This is an upstream problem in OpenLayers - that it should properly assign the class in Chrome and remove the image element in Safari and other browsers which show the 'broken image' icon.