This demo demonstrate the use of the TemplatePopup widget that display a popup on click on WMS layers. The popup is built from a resource option in the configuration file.

Click on the 'TemplatePopup - WMS' button, then click a Country Marker. This triggers a WMS GetFeatureInfo request at that location. The first result returned in displayed in a popup entirely customized in the "templatepopup" resource option. Each attribute value returned by the query can used. If it's a url path to an image, it can be used for a "img" tag. If it's a url, it can be used as a link.

Source : Wikipedia.