This section describes the formats of Apama's function definition and block definition files. It is important that developers adhere strictly to these formats when developing functions and blocks to be used in Apama scenarios.

Understanding the XML format is especially important for developers creating functions, because the function editor in Software AG Designer lets you work directly on a function definition file's XML code. Function definition files have an .fdf extension.

On the other hand, block developers are shielded from most of a block definition file's XML code by the Apama block editor, which automatically generates the block's boilerplate code and allows input only in sections of the file where user input is appropriate. Block definition files have a .bdf extension.