Saturday, 3 June 2017

Look ma, no tooltip requests!

So what does tiles of ascii-like content give us?

UTFGrid tiles allows us to pre-render tooltip interaction data. Because we're pre-rendering such data, no mapagent requests are ever made, we can fetch for such tiles just like other map image tiles.

If you remember my previous notes about MapGuide scalability, session repositories add memory and administrative burden/bookkeeping to the running MapGuide Server. If you can get away with not having to create a session repository and keeping it alive, you should. Currently, tooltip requests sadly, require a runtime map (thus, requiring a session be created first and the initial runtime map state to be saved to its session repository).

Because this is pre-rendered tiles of interaction data, paired with map image tiles, it's a very scalable map viewing solution. No CREATERUNTIMEMAP operation was needed to demonstrate this example, nor did we have to create or hit any session-based resources.

Also, because UTFGrids are accessed using the same XYZ tile access scheme, we can re-use the XYZ tile provider in the Tile Set Definition and just specify the new TileFormat of UTFGRID


Accessing UTFGrid tiles is just like accessing XYZ tiles, via the GETTILEIMAGE mapagent operation, but using the UTFGrid Tile Set Definition as the resource id.

The usual mapping suspects of OpenLayers and Leaflet already support UTFGrids, so you can easily take advantage of UTFGrids when it finally lands in MapGuide proper.

Now to make sure UTFGrid support also works on our Linux builds before I draft up that RFC.