Format class

The Format class is used to serialize and deserialize feature data. There are just two properties, a few methods, and a list of valid subclasses we should quickly cover.

Format class properties

You'll often run into a situation where you have a data file that is in a different projection than your map. For instance, if you are using a spherical Mercator projection for your map and the data is in EPSG:4326, you'll need to set the following two properties so that OpenLayers can transform the projection.

• externalProjection: {OpenLayers.Projection} This specifies the projection that the data is in.

• internalProject: {OpenLayers.Projection} This specifies the projection that the map (or the geometries that will be returned) is in.

  Note

  By default, you can only use the spherical Mercator and EPSG:4326 projections. If you wish to use a different projection, you will need to include the Proj4js library, which was covered in more detail in Chapter 4.

Format class methods

There are two primary...