⎕NEW creates a new instance of the Class, Dyalog GUI object, or .NET Type specified by Y.
Y must be a 1- or 2-item scalar or vector. The first item is a reference to a Class or to a .NET Type, or a character vector containing the name of a Dyalog GUI object.
The second item, if specified, contains the argument to be supplied to the Class or Type Constructor or a list of property/value pairs for a Dyalog GUI object.
The result R is a reference to a new instance of Class, Dyalog GUI object, or Type Y.
For further information, see Interface Guide.
Class Example
:Class Animal ∇ Name nm :Access Public :Implements Constructor ⎕DF nm ∇ :EndClass ⍝ Animal Donkey←⎕NEW Animal 'Eeyore' Donkey Eeyore
If ⎕NEW is called with just a Class reference (that is, without parameters for the Constructor), the default constructor will be called. A default constructor is defined by a niladic function with the :Implements Constructor attribute. For example, the Animal Class may be redefined as:
:Class Animal
∇ NoName
:Access Public
:Implements Constructor
⎕DF 'Noname'
∇
∇ Name nm
:Access Public
:Implements Constructor
⎕DF nm
∇
:EndClass ⍝ Animal
Horse←⎕NEW Animal
Horse
Noname
.NET Examples
⎕USING←'System' 'System.Web.Mail,System.Web.dll' dt←⎕NEW DateTime (2006 1 1) msg←⎕NEW MailMessage ⎕NC 'dt' 'msg' 'DateTime' 'MailMessage' 9.2 9.2 9.6 9.6
Note that .NET Types are accessed as follows.
If the name specified by the first item of Y would otherwise generate a VALUE ERROR, and ⎕USING has been set, APL attempts to load the Type specified by Y from the .NET assemblies (DLLs) specified in ⎕USING. If successful, the name specified by Y is entered into the SYMBOL TABLE with a name-class of 9.6. Subsequent references to that symbol (in this case DateTime) are resolved directly and do not involve any assembly searching.
Dyalog GUI Examples
F←⎕NEW ⊂'Form'
F
#.[Form]
To specify the initial values of any properties, Y[2] must be a vector (or scalar) of items each of which is of the form (PropertyName PropertyValue); the free-form syntax implemented by ⎕WC and ⎕WS is not allowed.
⎕NEW'Form'(⊂'Caption' 'Hello') #.[Form]
F←⎕NEW'Form'(('Caption' 'Hello')('Posn' (10 10)))
F
#.[Form]
Note that as ⎕NEW provides no facility to name a GUI object, the Event property should use the onEvent syntax so that a callback function (or the result of ⎕DQ) receives a ref to the object. Otherwise, without the onEvent syntax, the first element of the argument to a callback function will contain a character vector such as '[Form].[Button]' which merely describes the type of the object but does not identify the object itself.
cap←'Caption' 'Push Me'
ev← 'Event' ('onSelect' 'foo')
F.(B←⎕NEW'Button'#.(pos cap ev))
Note that you may not create an instance of OCXClass using ⎕NEW.