THIS PROJECT HAS BEEN MERGED INTO IFC-gen AND IS NO LONGER IN DEVELOPMENT HERE.

IFC-dotnet

An Industry Foundation Classes (IFC) library for .NET Core.

Pre-requisites

• .NET Core

To Build

cd src
dotnet build

To Test

cd tests
cd IFC-dotnet-test
dotnet xunit

Design Considerations

Most of the code in this repository is generated automatically using IFC-gen. The templates for code generation and certain base classes have been designed to generate an idiomatic C# library.

• All EXPRESS TYPE have a corresponding class derived from IfcType, which is a wrapper class whose Value property holds the actual value.
• All EXPRESS ENUM have a corresponding enum.
• All EXPRESS collection types: 'LIST', 'SET', and 'ARRAY', currently generate List<T> fields in C#. This solution does not conform to the EXPRESS specification for those types. So it will be updated in the future.
• EXPRESS SELECT types are created as classes derived from the Select base class. The Select base class has generic parameters corresponding to the types which can be selected in the SELECT. Additionally, the code generator creates one constructor for each selection type to aid in discovery of selectable types. Other languages which support discriminated unions may prefer to use that mechanism for modeling SELECT.
• All EXPRESS ENTITY have a corresponding class.
• All IFC attributes are generated as public class properties with a getter and setter. Chances are these will become more restrictive in the future. For those attributes not marked as OPTIONAL, the entity's corresponding class constructor will have parameters corresponding to the property, and a corresponding assignment will be generated in the constructor body.
• Attributes marked as DERIVED are not currently turned into properties. Although the grammar generates a parser which can understand DERIVE and WHERE statements, these are not currently converted to code in property or method bodies.
• Types derived from IfcRelationship do not have corresponding parameters in the generated constructors. Many types have many relationship properties. Adding all of these to the constructor made the constructors unwieldy. It's possible that these are required, but my present intuition is that a higher-level factory class for properly generating entities and establishing their relationships is a better way to do this. Whether these higher level libraries can also be auto-generated is a point on which I welcome all feedback.
• EXPRESS WHERE statements do not currently generate code. One possible pattern for this would be to generate static constructors for classes, placing the data validation logic in the static constructor and throwing an exception if the data validation fails. But, I feel like data validation needs to be done whenever the state of the object changes, so these data validation methods should either be reactive to property value changes, or they should live in a separate class containing testing methods for validating objects of certain types.