Programming Guide - Actian

External ClassesHow You Can Use External ClassesTo use an external object in OpenROAD, you must first register the library thatcontains the external objects by using the External Class Library Editor.Next, you have the option of doing either or both of the following:• Adding external objects to an OpenROAD frame using the Frame Editor• Declaring variables that reference external classesFor more information about these procedures and facilities, see the UserGuide.When you register an external class library, be aware that one library can havemore than one external class. For example, registering a single external classlibrary might provide three external classes that can be used in an OpenROADapplication.Dynamic Programming with External ObjectsThe ExtObjField class is a formfield that provides the wrapper for a singleexternal object. By using the InsertObject method of the ExtObjField class, youcan dynamically populate a form with external objects. For an example of howto do this, see the Language Reference Guide online help.Non-Formfield External ObjectsNot all external objects can be displayed in a form. One example would be anExcel automation object. Because a Microsoft Excel spreadsheet is anautomation object, you cannot display it in an OpenROAD frame; however, youcan use OpenROAD to print or manipulate it.How You Can Use Collections with External ClassesActiveX objects can be collections, which are like sets, and can be used asarrays if they have been declared as an OpenROAD collection. If you want toindex into a collection using the array syntax, you first must declare it as anOpenROAD collection.136 Programming Guide