Howto Make Openlayers In Sahana Show Multi Layers (Overlay)

Proof of Concept

1. I’m using Sahana version 0.6.2 stable release
2. Sahana read the configuration from MySQL and then file configuration. So, we have to change all configuration in config values (Administration > Config Utils > Config Values) and then edit conf.inc file.
3. Sahana only provides 2 layers in openlayers (this is the default configuration). You can see this in Config Values, if we want more layers, we should add manually in conf.inc file.
4. Sahana produce a map in JPG format. We all know that JPG does not support transparency, so we should change this with PNG. We will adding some PHP codes in openlayers_fns.php.