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In OpenLayers I'm having a missing tile problem where it generates a missing link icon and a pink background. I found several threads including this one saying to add this code OpenLayers.Util.onImageLoadError = function() {this.src = '/img/blank.png';};

Sorry if this is dumb, but should my blank.png just be a 1px transparent png24? And also where should the img folder go?

Sorry, I've tried 1px, 256px, png24, png8, gif and putting the img folder and/or file in every conceivable place and I'm having no luck. Maybe you'll see something in these screenshots.

I've also tried an image with color to see if I can notice any actual change, so that's why the blank.png file looks red in the Finder thumbnail.

chrome code file structure

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  • you don't need an image - it is just there to force the tile cache to get the 'real' images from Openlayers mobile - openlayers.org/dev/examples/mobile.html
    – Mapperz
    Commented Jun 25, 2012 at 17:23
  • I'm sorry, I'm new to Open Layers. Could you please paste how this code should read? OpenLayers.Util.onImageLoadError = function() {this.src = '/img/blank.png';};
    – billted98
    Commented Jun 25, 2012 at 18:45

1 Answer 1

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Woohoo! Figured it out. This thread had the solution to change the CSS rather than the JS.

.olImageLoadError { 
    /* when OL encounters a 404, don't display the pink image */
    display: none !important;
}

This help article was helpful too, but I have not idea how to tell TileMill/MapBox to generate blank tiles rather than missing tiles. I'll get there someday.

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  • TileMill will skip empty tiles; in map clients there's always a way to handle 404s somewhat gracefully and skipping tiles with no data is much more performant than rendering blank tiles everywhere.
    – tmcw
    Commented Jun 26, 2012 at 17:26
  • Agreed. Any ideas are most surely welcome :) I haven't been able to figure it out so far.
    – billted98
    Commented Jun 27, 2012 at 14:16

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