Importing shapefiles

In the next example, called ch09_shp, we implement a method to import binary layers to our maps. Shapefile is an old specification to store vector data; however, it is still a very common and popular exchange format. It stores the geometry in a binary file, which has an shp MIME type. There are usually at least three more files along with the geometry. The shx file stores the shape indexes of the geometries in a binary format, providing an internal spatial indexing for faster lookups. The prj file is an ASCII file containing the projection string of the layer, while the dbf file is a dBASE database file containing attribute data. For this example to work, we will need at least the shp and dbf files of a shapefile.

Editing the HTML file

First, let's edit the HTML file of the example. In this example, we will implement an easy way and replace the function associated with the Add Vector Layer button in our layer tree. This way, we don't have to touch the GUI elements, just...