Whenever you wish to use an Absyntax project in conjunction with Microsoft Excel (typically to perform some kind of transformation on data that is bound to a workbook), you must define a project invocation rule. Each such rule encapsulates:
the target Absyntax project to be invoked;
whether the project is reloaded before each invocation;
the way in which data is to be acquired from a worksheet and passed into the project;
the way in which data emitted from the project is to be written to a worksheet;
the amount of time that the Absyntax runtime service will allow the project invocation to complete.
Target Project
The target Absyntax project to be invoked is expressed as the full path to a file with an "apj" extension.
Reloading a Project
For performance reasons it is advantageous to leave a project loaded in memory between invocations because project-loading is a relatively slow process. This is managed automatically. However, once a project is loaded then any changes made to the source project file can only be realised if the project is reloaded. A project invocation rule allows you to specify whether a project should be reloaded before each invocation. This capability is particularly useful if you are in the process of developing or maintaining a project at the same time as using it with the Absyntax Excel Add-in. See Loading and Unloading a Project for more details.
Input and Output Data
You are expected to understand the input and output data requirements of the Absyntax projects you want to invoke. It is not necessary for all projects to require input data and emit output data, and there may be good reasons why you might want to invoke a project that either requires no input data or emits no output data. In any case you must specify whether and how input data are acquired and presented to a project prior to invocation, and whether and how any output data emitted by the project are to be handled.
Time Limit
Each project invocation rule enforces a mandatory time limit. This limit is used to constrain the amount of time that an invoked project has to complete its work. It also ensures that badly formed projects are terminated in a timely manner. The minimum time limit is one second; the default is ten seconds; the maximum is 999 days.
