Windows Presentation Foundation

Windows Presentation Foundation (WPF) is a graphical system that includes a programmable Graphical User Interface. It is supplied as a set of Microsoft .NET assemblies, and is supported on all current Microsoft Windows platforms.

The WPF GUI is more sophisticated and powerful than either Dyalog's own built-in GUI or the GUI provided by Windows Forms.

Like any other set of .NET classes, WFP can be integrated into Dyalog applications through the .NET interface. Dyalog users can, therefore, develop GUI applications that are based on WPF as an alternative to the built-in Dyalog GUI or Windows Forms.

In addition to its advanced GUI capabilities, WPF supports data binding. Data binding is complex, but essentially it allows a property of a user-interface object (such as the Text property of a TextBox object) to be bound to some data, so that when the data changes, the bound property of the object changes.

Dyalog includes a data binding function in the form of an I-beam – 2015⌶ – that supports data binding to APL arrays and namespaces. This function might be replaced by one or more system functions in a future Dyalog version.

A WPF GUI can be built dynamically by creating a set of component objects (using ⎕NEW) in a similar way to the Dyalog GUI and Windows Forms. However, the same user interface can instead be specified statically using XAML, a text mark-up system that describes the GUI using XML. When combined with data binding, this allows the application logic and the user interface to be developed and maintained separately.