9. Included Applications

9 Included Applications

9.1 Introduction

An application can include other applications. An included application has its own application directory and .app file, but it is started as part of the supervisor tree of another application.

An application can only be included by one other application.

An included application can include other applications.

An application that is not included by any other application is called a primary application.

Figure 9.1: Primary Application and Included Applications

The application controller automatically loads any included applications when loading a primary application, but does not start them. Instead, the top supervisor of the included application must be started by a supervisor in the including application.

This means that when running, an included