OpenLayers Users,
I am currently replacing an ArcIMS HTML Viewer application with a new OpenLayers interface which will be a great leap from what they have in general navigation usability. I think that I won't have much trouble replacing almost all of the other functionality (Identify, Measure, Select, etc.) provided by the ArcIMS application but there is one that I am not sure of the best way to handle in order to port over the same effect and response... and that is a feature we call MapTips. If you are not familiar with the term "MapTips" then here is a brief description - in the ArcIMS application only one layer can be selected/active at a time. We have a button that toggles MapTips on or off for the selected layer. When it is turned on the user can just mouse over any feature from that layer on the map and a pop up (DIV) shows attribute data for the specific item they are hovering over. It's basically a quick identify on a feature but the information has been preloaded so it is very quick and easy to use. If you are not familiar with ArcIMS web sites then here is some information on how they accomplish this - by default, at least for older (pre 9.2) versions of ArcIMS, only a single image is returned at any given time to draw the entire map. So, to create MapTips, a spatial query is done for the current extent and selected layer ... from the results of this query an image map is created for the current map image thus making the "hot spots" that will capture the mouse over event a trigger the showing of the attribute info in the DIV. So, using OpenLayers instead of the generic ArcIMS HTML Viewer poses a challenge with the tiles/grid of the map images. At least it means that we can't use exactly the same methodology as before, but maybe I could take the same idea and make an image map for each tile that comes in from my WMS service. Or, maybe I could have markers appear on all the features of the selected layer when MapTips are toggled on so they can handle the mouse over events. But, how will that be handled dynamically? When the user navigates outside of the current view and new features come into view they need to have a marker appear on them. Are the more alternatives that might be a better way to handle this scenario? I was just curious to see if anyone has attempted something like this with OpenLayers already or if anyone has thoughts on the best areas of OpenLayers to utilize or hook into to make this functionality work in a graceful manner. Thanks in advance for any and all comments, Wally Atkins
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