Programming Guide : Glossary
 
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Glossary
3GL procedure
A 3GL procedure is a procedure written in a third-generation language, such as C, that you can call by name from a script or 4GL procedure. 3GL procedures are used to perform operations that are outside the scope of OpenROAD but are available from a 3GL.
abstract class
General classes that are used for classification only are known as abstract classes in object‑oriented programming.
aggregate function (set function)
An aggregate function returns a single value based on the contents of a column. Aggregate functions are also called set functions.
aggregation
The aggregation inter-class relationship describes an object that is composed of separate, smaller objects that function together.
array
An array is a named set of rows in which each row is a reference variable that points to an object of a given system or user class.
assistant
Assistants are procedures that can be attached to a frame or a field template. They can be designed to prompt the user for varying amounts of information used to customize the frame or field according to the user's needs or to perform a certain function each time the field or frame is invoked.
autocommit on
Autocommit on describes a transaction management state in which each database statement is an individual transaction automatically committed when it is successfully executed.
BitmapObject class
The BitmapObject class provides attributes and methods that enable you to manipulate the images displayed in an image field.
casting
Casting involves making the system class of a generic object explicit.
collection
A collection is an object that contains a group of related objects.
command
A command is an operation that you execute from an OpenROAD menu or at the operating system level.
concurrency control
Concurrency control refers to the management of shared data so that simultaneous users can access and update the data with little or no wait time while data integrity is maintained.
cursor
A cursor is a row marker that designates an individual row in the select statement's result table (the set of rows returned by a non-singleton select).
data entry error handler
A data entry error handler is a global or local procedure written in 4GL that gains control as a result of a user typing invalid data into an entry field. The error condition is detected when the entry field loses input focus, or the GetFieldValue method is executed on the entry field.
database event
Database events are user-defined events. They are created and manipulated using SQL statements and stored in a database. Database events are a way for two programs that are connected to the same database to communicate.
database procedure
A database procedure is a data-oriented procedure stored in the database and executed within the database server that you can call by name in a script or 4GL procedure. Database procedures are often used to increase performance and help ensure data integrity and consistency.
dereferencing colon
A dereferencing colon preceding a dynamic name indicates that you are using the contents of a variable to supply the value for an OpenROAD name.
dynamic array variable
A dynamic array variable is a named set of rows.
dynamic frame
Dynamic frames are frames that perform operations based on decisions made by the user at runtime.
dynamic name
A dynamic name is a name that you can use in a statement either dynamically (when you run the application) or statically (when you create the application).
DynamicFrame frame
The DynamicFrame frame at runtime displays the starting frame that provides the user with a choice of database tables. The starting frame then builds a second frame that presents the columns of the chosen table as simple fields on a form.
effective user
The effective user is the user name under which the application is running.
encapsulation
The process of allowing only the object itself to have access to its attributes and methods is called encapsulation.
event block
An event block is a sequence of statements associated with one or more specific events.
event chain
An event chain is a linked series of events triggered by a starting event.
expression
Expressions are language constructs that resolve to a value, a set of values, or TRUE or FALSE.
external class
An external class defines the class properties, methods, and events for one or more external objects.
field variables
Field and menu item variables are variables that are associated with the value in a field or menu item. These variables are not associated with the object represented by the field or menu item.
frame
A frame is a window that consists of a form, with or without a menu, used to display and input data.
frame event
Frame events include events that are triggered by user interactions with the frame's window, such as the WindowResized event that is triggered when the user resizes the window. Frame events also include interactions with the background of the frame, such as the Details event, which is triggered for the frame when the user clicks the Details button on the area surrounding the fields.
frame mode
A frame mode is a name given to a particular set of field and menu biases.
FrameExec object
FrameExec is the OpenROAD system class that contains information about the running instance of a frame, such as the parent frame, the list of fields that are currently selected, and the starting menu for the frame.
FrameForm object
A FrameForm object is a special case of a subform that encloses the full set of FormField objects in a frame.
FrameSource object
The FrameSource object contains a frame's source definition, its initial settings when it is called or opened.
ghost frame
Ghost frames differ from other OpenROAD frames in that they do not contain forms (making them invisible to the user).
global 4GL procedure
A global 4GL procedure is a routine written in 4GL that you can call by name from a script or another procedure. The procedure is a component of an application and is stored in the application's database.
global variable
Global variables provide data that is pertinent to the entire application and are available for use in any script or procedure.
hexadecimal constant
Hexadecimal constants are a special version of string literals. They represent characters expressed in hexadecimal notation and are most often used for nonprintable characters such as a newline character.
image field
An image field is a rectangular boundary, like a picture frame, in which you can display bitmap images that are stored either in files or in the database.
image trim
Unlike an image field, image trim displays a single bitmap image.
ImageField object
The ImageField object describes the image field that you use to display the bitmap images. The ImageField object specifies how to display the image.
include script
Include scripts are scripts that contain 4GL code that you can include anywhere in your frame, procedure, or user class script by using the #include statement.
inheritance hierarchy
With inheritance hierarchy, a class that is a child of another class is considered its subclass and a class that is the parent of another class is considered its superclass. Each subclass inherits the attributes and methods for all its superclasses.
listview field
A list view field lets the end user view and optionally manipulate or edit a list of items.
local variable
Local variables contain data that is associated with a specific frame, procedure, method, field script, or event block.
macro variable
Macro variables are substitution parameters that you can define and give a value.
menu event
Menu events are events triggered when a user selects a menu item.
menu item variables
Field and menu item variables are variables that are associated with the value in a field or menu item. These variables are not associated with the object represented by the field or menu item.
named constant
A named constant is a literal value to which you give a name. You can then use the name in place of the constant in any 4GL expression.
null
A null is an undefined or unknown value. A null is not the same as a zero, a blank, or an empty string.
null constant
A null constant is represented by the special keyword null. You use this keyword to assign a null to a nullable variable or database column.
object
An object is a compound data structure that holds values that you can manipulate.
PaletteField object
PaletteField objects display a list of values, represented as images, from which the user selects a single value.
polymorphism
The process of a subclass's method superseding the behavior of an identically-named method defined for a superclass is called polymorphism.
procedure
A procedure is a named piece of code that performs a single task.
procedure handle (ProcHandle object)
A procedure handle (ProcHandle object) represents a global or local procedure and the scope in which to execute it.
procedure statement
The procedure statement defines a 4GL procedure. This statement declares the parameters for the procedure and provides the actual processing statements.
reference variable
A reference variable is a variable that points to an object of a given class, letting you access the value of an object.
script
A script is a set of statements that define the actions performed by a procedure or frame.
select loop
A select loop is a block of 4GL statements that are performed on each row returned by the select statement. The loop ends when there are no more rows or an endloop statement is encountered.
simple variable
A simple variable is a single data item. It contains only one value.
source breakpoint
A source breakpoint is a defined place in a script where the application passes control to the Debugger. Source breakpoints can pass control to the Debugger only between statements.
statement
A statement is an operation that you place within a program or called procedure.
StringObject class
The StringObject class is an in-memory text string of any length. It provides methods that enable you to manipulate a text by extracting, truncating, and concatenating strings. It also provides the attributes and methods you use for storing and updating the strings, either in standard text files or in the database.
system variable
System variables are built-in variables that are available in all frames and scripts.
table field
A table field is a composite field comprised of active fields arranged in rows and columns. Each column in the table field maps to one attribute of the class associated with the array and each table field row displays one row of the array. The fields are usually entry fields, but can be of any kind, such as image or toggle fields.
transaction
A transaction is one or more database statements processed as a single, indivisible unit.
tree
A tree contains a collection of treenode objects. The top treenode in the hierarchy is the root node.
Tree class
The Tree class is used to manage data that has an hierarchical structure.
TreeNode class
The TreeNode class represents a node that contains data for a single node in a tree.
treeview field
A tree view field presents the end user with a hierarchical list of items in a tree structure that can be expanded or collapsed.
user class script
A user class script contains methods that you can invoke to use with variables defined for a user class.
user event
A user event is an event that you trigger with 4GL code (rather than an event triggered directly by a user action).