Control Link Technical Guide
1.1 Overview

This document is a technical guide that deals with the <Control Link> mechanism in the SEDRIS DRM, as well as associated functions. <Control Link> exists to express a relationship between their target objects and a set of controlling <Expression> instances, where each <Expression> specifies some field value of the target object. This allows a user to specify objects with moving parts, objects that change state, and <Model> objects that can be customized when they are instanced, among other possible uses.

Since a <Control Link> requires a priori knowledge of the field structure of its target objects, each possible class of target object has its own specialized subclass of <Control Link>. The <Control Link> class itself exists to abstract the common characteristics of its subclasses.

1.2 Prerequisites

It is recommended that the following documents from the SEDRIS Technology Documentation Set (see Section 1.2) be reviewed prior to reading this document.

  • Part 3: SEDRIS Basics
  • Part 4, Volume 1: Technical Overview
  • Part 4, Volume 2: The SEDRIS Data Representation Model
  • Part 4, Volume 3: Examples of Using the Data Representation Model
  • Part 4, Volume 12: Application Programmer's Interface Overview
1.3 For Additional Information on SEDRIS

This document is part of a larger set of overview and technical documents on SEDRIS, the Technology Documentation Set. The Technology Documentation Set describes the why, what, and how of SEDRIS.

The Technology Documentation Set, listed below, is available at the SEDRIS web site ( An overview of the contents of each "part" of the documentation set is provided in Part 1. A detailed description of the individual "volumes" contained in Part 4 is provided in Volume 1.

1.4 Document Conventions and Notations

Throughout the SEDRIS Technology Documentation Set, special conventions and notations are implemented in the written text of documents to distinguish between and add emphasis to various computer-related or SEDRIS-specific terms. The table below defines these conventions and notations.

Reverse video
window buttons/selections/choices/etc.
<Key or Class> <Shift> keys on the keyboard
<Colour Data> SEDRIS DRM class names
Courier font src/lib/api_impl/ ... directory, file, transmittal, library names
gmake env command line input
"false" variable names, values, and coding examples
italics Internet addresses
gmake software, window, mode, function, option, etc. names
Part 1: Intro to document/section titles
not always for emphasis
"quotes" "generic" highlight or call attention to

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