CBA ItemBuilder Workshop: Session 05

Ulf Kroehne

Paris, 2022/11/07 - 2022/11/08

Session 05: Variables and Value Maps

Overview Session 05

Definition of Variables

  • Types
  • Debugging

Display of Variables

  • Variable Value Displays
  • Value Maps

Use of Variables

  • Drag and Drop

Variables-View

Variables are configured in the Variables-view (main menu Project > Browse Variables or toolbar icon).

  • Variables are defined for the Project File (i.e., available for all Tasks within a Project)
  • Main options of the Variables-view: Add Variables, Edit, and Delete

Named Values:

  • Assign names (used in syntax) to values
  • Optional, but useful to avoid magic numbers

Typed Variables

Variables are part of the logic layer of the CBA ItemBuilder and most often used together with Conditional Links or Finite-State Machines.

  • Variables are defined by a unique Name, a Type (INTEGER, NUMBER, STRING or BOOLEAN) and a default Value.
  • INTEGER variables (i.e., numbers without decimal places) are typically used.
  • Valid variable names (like page names and user-defined ids) use only letters, digits, and underscore, and the first character must not be a digit.

Variables – Overview

Variables and (Map-Based) Variable Displays are used for many purposes, for instance, to implement Drag-and-Drop response formats.

What can change values of variables?

  • Input components
  • Drag-and-drop operations
  • Task Initialization
  • Operators
    • in Finite-State Machine Rules
    • in Conditional Links

How are values of variables used?

  • Display information (using Variable Displays and optional Maps)
  • Scoring of responses
  • Conditions
    • in Finite-State Machine Rules
    • in Conditional Links1

Variable Value Displays

Layout Options

Link Variable

  • VariableValueDisplays are linked to a variable using Context Menu
  • Formatted using the Properties-view, including position (X/Y) and size (Width/Height)

State Machine Debug Window

For item development, the Preview provides the State Machine Debug Window that lists (beyond other things) the current value of variables.

During Preview:

  • Value of variables can be debugged in the Preview

  • Strg/Ctrl + M is the (default) hotkey for the State-Machine Debugger

  • Settings (main menu Utilities > Open preferences)

Value Maps-View

Value Maps are used to translate numeric values (or ranges) into Text, Images, Video and/or Audio.

  • Multiple Maps can be defined (each require a unique Name).
  • Each entry requires a Guard (the value, range or default *) and can use Texts or refer to resources (Images, Audio, Video from the Resource Browser).

Map-Based Variable Displays

Layout Options for Value Display Type TEXT

Link Value Map (& Variable)

  • MapBasedVariableDisplays are similar to VariableValueDisplays, but are linked to a Variable and to a Map.
  • Entries in the Map are ordered (i.e., the first guard is used, * is used last).

Map-Based Variable Displays: Display Types

By default, MapBasedVariableDisplays show the Text of the linked Value Map. If Images, Audio or Video should be used, change the property Value Display Type in the Properties-view.

Configuration in the Properties-View:

  • MapBasedVariableDisplays can be Linked to Events and work as interactive buttons or to display text information or, images.
  • MapBasedVariableDisplays can also be used as multimedia-player.

Drag-and-Drop – Two Concepts

The CBA ItemBuilder supports two drag-and-drop concepts, but fixed drag-and-drop is used more often.

  • Free Drag-and-Drop: Position of elements changes
  • Fixed Drag-and-Drop: Positions remain, only elements change

Example:

  • The dices on the left side can be moved (with the Panel).
  • Drag-and-drop between left and right is possible.

Drag-and-Drop – Real-Life Examples (1)

Drag-and-Drop – Real-Life Examples (2)

Drag-and-Drop – Variables and Maps

Simple Illustration

  • Each time a successful drag-and-drop operation is completed, the variable change values.
  • Instead of numeric values, the mapped images are shown.

Variables

  • position one (V_1)
  • position two (V_2)
  • position three (V_3)

Values Map

Value Image
2
3
4

Drag-and-Drop – Modes

The property Drop Mode of MapBasedVariableDisplays defines the drag-and-drop behavior.

  • All 3 different modes are illustrated in this item.
  • Explore how values of variables are changed after drag-and-drop operations!
  • DROP_SWITCH: The source variable and the target variable switch values
  • DROP_MOVE: The value of the source variable is moved to the target variable (and the source variable becomes zero)
  • DROP_COPY: The value of the source variable is copied to the target variable (but the source variable keeps the value)

Drag-and-Drop – How-to?

Defining a first MapBasedVariableDisplay:

  • Add the components to the page.
  • Link variable and map (Link Variable / Value Map).
  • Configure Value Display Type (if not TEXT).

Configure if a drag-and-drop operation can…

  • start from the component (Drag Source: true)
  • end at the component (Drop Target: true)

Configure how variable values are changed:

  • Drop mode (DROP_COPY, DROP_MOVE or DROP_SWITCH)

Duplicate the configured component.

Multiple Drag-and-Drop Interactions per Page

How to Create Groups?

Problem

  • By default, drag-and-drop is possible across all components of type MapBasedVariableDisplays.

  • This is not always what’s needed.

Solution:

  • Option A: Unique values and different maps (see example above)
  • Option B: Use drop events to check for valid operations (see session 11)

End of Session 05: Variables and Value Maps

Important:

  • MapBasedVariableDisplays are introduced here for drag-and-droop, but the components can also used as buttons or to display information.

Helpful to remember:

  • The Variables-view can be opened using the menu Project > Browse Variables.
  • The Variables-view can be opened using the menu Project > Browse Value Maps.
  • How the value of variables is changed after drag-and drop is defined by the Drop Mode.
  • The State Machine Debug Window shows value of all variables (but also additional information required to check Finite-State Machines).

Additional tips:

  • Don’t forget to define the Value Display Type.
  • In the hands-on in the next session 06, Variables and Value Maps will be used to create drag-and-drop response formats..