OpenLayers layer management

In the previous post I wrote about layer creation. This is only a part of the capabilities of a good GIS application. A good application can also manage layers in an efficient way. Fortunately, OpenLayers libraries have predefined functions for layer management. They provide a great base to build upon and create dynamic Web GIS applications. Some of the basic tasks of layer management are adding and removing layers, changing layer order, listing rendered layers, and changing layer styles. Off course, they have to do it during the workflow, without reloading the page. I will show a few of these functions with a live example in this post.

OpenLayers layer creation

Layers are a core concept in every GIS software. They are collections of contiguous spatial data. You can stack layers on each other, perform an operation on them, style them individually, etc. Fortunately, OpenLayers is outstanding with its layer management. Every raster dataset is contained in a layer. For vector data, you can group features to as many layers as you like. Layers can be accessed, modified or removed after they are constructed. As the layer changes, the map object will track the changes, so it will take effect on the visualization, too. In the following post, I will write about OpenLayers layers.