The Impex library provides a uniform way of importing data from files written by non-GEOS applications, and of exporting data to files written in these formats. It also saves coding time. Every outside format needs a single translation library, which translates between the Metafile format and the format for that specific library. The Impex objects provide all the necessary user interface (though the libraries and applications can add more), and also do all necessary interaction with the translation libraries.
In order to import data, an application will need to have an ImportControl object. Similarly, in order to export data, an application will need an ExportControl. Most applications that produce data files will want to use both of these objects.
Some applications will create a new GEOS file for imported data; others will add it into the current document, as if they were pasting data from the clipboard. Similarly, some applications will export the entire current document; others will export only the current selection, if any. This is left entirely to the discretion of the application.
The Impex Objects
How the Impex Objects Work