AutoCAD Architecture detail components are not custom objects in AutoCAD. They are made up of simple entities like line, arc, polyline, block, and hatch. Usually, the various entities that make up a detail component are grouped as an anonymous block so that they can easily be copied or moved like a single entity. But a detail component can also be as simple as a polyline boundary with a hatch interior. This accommodates the type of component for which it is natural to use the STRETCH command. The exact makeup of the component is left to the discretion of the developer.
Each Detail Component is also stamped with “Xdata” (Extended Entity Data) that identifies where it came from in the original database of components. This data can be used later to retrieve additional information or create another component of the same type.
Detail components are integrated with the Property palette and Tool palette systems. However, the details framework handles this interaction automatically, and an author of a new detail component only has to provide a simple description of what type of data should appear.
The details framework includes four main components:
- Database of Components and Sizes
- Recipe Specification
- Recipe Implementation
- Framework Utilities
Database of Components and Sizes
The AEC Detail Component database is a Microsoft
Access database, which contains a size table for each available component, as well as several related tables that support the overall structure of the database. End users can add or modify existing component tables through the user interface provided by the Detail Component Manager dialog box, but more advanced customization requires Microsoft Access.
Recipe Specification
A Recipe Specification (RecipeSpec) is an XML file that describes the different Recipes that can be used to create a particular component in AutoCAD. For each Recipe, it identifies the types of controls (prompts) that should appear in the Properties palette and specifies how to call the function that implements the given Recipe. The RecipeSpec also provides view-specific information such as the layers and hatch patterns to use when creating the component.
Recipe Implementation
A Recipe Implementation is (usually) a small piece of code that creates the component in AutoCAD. The Recipe Implementation can be written in ObjectARX C++, VBA (Visual Basic for Applications), or any Microsoft .NET language (such as C# or Visual Basic .NET). The Recipe can be as easy as a simple block insert, or it can involve more complex operations, such as bringing up a dialog box with many choices.
Framework Utilities
The Framework utilities make the job of implementing a Recipe much easier. They provide many of the common functions to look up data from the database and from the user controls that populate the Properties palette. These utilities also provide a number of common “Jigs” that help place the component once it is created.