JSTS is a JavaScript library of spatial predicates and functions for processing geometry. It is a very powerful tool that allows you to do all kinds of modifications in your map, for example create a buffer zone or insure a working topology. JSTS is also a JavScript port of the well established Java library JTS. eVouala allows you to use JSTS scripts. Here is an example that shows you how to proceed in eVouala. In this example, you will learn how to create a buffer circle around a Lat/Long point.
First, you need a data source added to a map as a render layer. See the How to make a layer render as a vector or add a vector layer to a map article for more details on this topic.
Once you have a data source that is rendered as a vector layer, you can create a mapping application in eVouala in which you have your data source added as a map. In this app, go the Edit application page and click on the Advanced... button. You first need to specify the source of your JavaScript. To do so, enter this code in the Source box:
Then, enter this code in the Script box to create the buffer on a Lat/Long point:
eVouala!
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