Common Object Model

Overview of the most important class types found in the NX Open API. Full detail is in the NX Open API Reference for each language; the object model itself is identical across all NX Open languages. Classes are organized into namespaces by application area.

NX Open classes

• TaggedObject — Base class for any class representing entities in the NX model (e.g. Line, Extrude). Represents persistent entities (saved with the part), though some TaggedObject classes represent non-persistent entities. Defining trait: has a Tag usable to interoperate with the UF API.
• NXObject — Inherits from TaggedObject. Adds methods/properties for getting and setting names and attributes on the entity.
• TransientObject — Represents something without a Tag, not saved with the part. Its Dispose method must be called to release it. Garbage-collected languages call Dispose automatically; in C++ it must be called explicitly.
• TaggedObjectCollection — Base class for collections of tagged objects; typically also has methods to create new tagged objects (e.g. CurveCollection creates new curves). Used to enumerate all objects of a type in a part, e.g. all curves:

  Dim curve As NXOpen.Curve
  For Each curve In part.Curves
     ...
  Next
  

  See "Accessing Bodies, Faces, and Edges" for more on collections.
• Session and UI — The "gateway" classes for the API; all other object references are obtained directly or indirectly through them. UI is only usable when the program runs inside the NX user interface (not usable in Batch mode).
• Part — Represents an NX part. Contains many TaggedObjectCollection members for obtaining/creating tagged objects, e.g. Part.Features (a collection of all features in the part) can yield FeatureBuilder objects for creating or editing features.
• Builder — Features and many other entities are created/edited through a Builder class. Builders expose methods (or .NET properties) to get/set the defining data for the entity, generally mirroring the corresponding UI command's input data; builders can also be queried. Call Commit to create the entity or apply edits, and Destroy when finished with the builder.

Browsing classes through an IDE

• Visual Studio: after referencing NXOpen.dll or NXOpenUI.dll, use the Object Browser to browse NX Open classes/documentation; IntelliSense works with NX Open classes.
• Eclipse: after referencing NXOpen.jar, use Eclipse's class browser and "content assist" (Eclipse's IntelliSense equivalent).

Refer to your IDE's own documentation for further detail.