Chapter 4: ActiveX Client Interfaces

JCollection interface

Description

Type library name	JaguarTypeLibrary
DLL name	jagproxy.dll

Represents a collection of objects or primitive data values; the ActiveX mapping for CORBA IDL sequences used as method parameter or return types in component methods.

Properties

Count as Integer: The number of available items.

Item(index as Integer) as Object: Set or retrieve an item’s value. The first item has index 0. All VARIANT values are allowed, except for arrays. When setting item values, index can be any positive integer starting with 0, and the value can be any type supported by the ActiveX client proxy and ActiveX component dispatcher. See Chapter 20, “Creating ActiveX Clients,” in the EAServer Programmer’s Guide for a list of supported types.

Usage

JCollection represents an IDL sequence. Any return value or parameter that is defined as an IDL sequence in a EAServer IDL interface is represented as a JCollection in the equivalent ActiveX proxy interface. The JCollection contains the ActiveX equivalent for the base type of the IDL sequence. Nested IDL sequences map to nested JCollection instances.

Iterating over a collections items

You can iterate over the items in a JCollection instance using a For ... To loop or a For Each ... In loop. The following example shows a For ... To loop:

Dim stringJColl as JaguarTypeLibrary.JCollection

Set stringJColl = myComp.methodThatReturnsSequenceOfString()

Dim stringItem as String
Dim iter as Integer

For iter = 1 To stringJColl.Count
  stringItem = Format(stringJColl.Item(iter - 1))
Next iter

The following example shows a For Each ... In loop that iterates through all items in the collection myJColl:

Dim myJColl as JaguarTypeLibrary.JCollection

Set myJColl = myComp.methodThatReturnsSequenceOfString()

Dim myObject as Object
For Each myObject in myJColl
  Dim strItem as String
  strItem = format(MyObject)
Next

Nested collections

The following example shows how to iterate over items in a nested collection. In the example, outerC is a JCollection instance that contains JCollection instances as items:

Dim outerC as JaguarTypeLibrary.JCollection

set outerC = myComp.methodThatReturnsNestedSequence()

Dim innerC as JaguarTypeLibrary.JCollection
Dim strItem as String
Dim i as Integer
Dim j as Integer

For i=1 to outerC.Count
  innerC = outerC.Item(i - 1)
  For j=1 to innerC.Count
    strItem = Format(innerC.Item(j - 1))
  Next j
Next i

In a collection innerC nested inside another collection outerC, the j’th item in the i’th nested collection can be accessed directly as follows:

Dim outerC as JaguarTypeLibrary.JCollection

set outerC = myComp.methodThatReturnsNestedSequence()

Dim innerC as JaguarTypeLibrary.JCollection
Dim myObject as Object
i as Integer
Dim j as Integer

myObject = outerC.Item(i).Item(j)