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- Declaring enumerations
- Passing an enumeration as a parameter to a procedure
- Special cases
- Extensible enumerations
- Creating aliases in an enumeration
- Associated values
- Associated properties
- Available WLanguage functions
- Limitations
Enumeration (Variable type) In french: Enumeration
An enumeration is a set of values. Only a value of an enumeration data set can be assigned to an Enumeration variable or parameter. // Declaration code
// Declare an enumeration
RobotType is Enumération
Walk
Stopped
InMaintenance
OutOfOrder
END
// Declare an Enumeration variable
Post1 is RobotType
// Assign the variable
Post1 = Walk
// Post1 = 1 // Displays a compilation error
// Post1 = "Walk" // Displays a compilation error
Syntax
Declaring an enumeration value Hide the details
<Enumeration name> is Enumeration
<Enumeration values>
END
<Enumeration name>: Name of the enumeration value to be declared <Enumeration values>: Different values that can be taken by the enumeration. <END>: End of declaration.
Declaring an Enumeration variable Hide the details
<Variable name> is <Enumeration name>
<Variable name>: Name of the Enumeration variable to be declared. <Enumeration name>: Name of a previously declared enumeration. The default enumeration value corresponds to the first enumeration value. Remarks An enumeration must be declared in: - The project initialization code so that it can be used in all the processes of the project (code of the project, windows, controls, procedures, etc.).
- The global declaration code of a window so that it can be used in all the processes of the window (code of the window, controls in the window, local procedures, etc.).
- The opening code of a report so that it can be used in all the processes of the report (code of the report, controls in the report, local procedures, etc.).
- The class declaration code so that it can be used in the class.
- To access this enumeration from a class method, use the following syntax:
- To access this enumeration from outside the class, use the following syntax:
"<Class name>::<Enumeration name>"
- The declaration code of a set of procedures so that it can be used in all the procedures of the set.
Remark: An enumeration is always global: - to a project,
- to a window,
- to a report,
- to a class.
Passing an enumeration as a parameter to a procedure An Enumeration variable can be passed as a parameter to a procedure. To do so, use the following syntax: <Procedure name>(<Name of enumeration variable>) For example: // Procedure with an Enumeration parameter
PROCÉDURE OperatingMode(p is RobotType)
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// Calls with an Enumeration parameter
OperatingMode(Walk)
OperatingMode(1) // Displays a compilation error
OperatingMode("A") // Displays a compilation error
Special cases - Assisted input: Assisted input for an enumeration-type parameter proposes the various enumeration values.
- Order of values: The operators <, <=, >, >= are available on enumerations as well as automatic sorting operations (ArraySort, ArraySeek, ...). The order of the values in the enumeration is the order in which these values are declared.
Example:
// Declaration code
// Declare an enumeration
RobotType is Enumération
Walk
Stopped
InMaintenance
OutOfOrder
END
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// Declare an Enumeration variable
Post1 is RobotType
// Assign the variable
Post1 = Walk
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...
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IF Post1>Stopped THEN
Info("The robot encounters a problem")
END
Extensible enumerations You can include one or more values from other enumerations and add new values. The following syntax is used: <Enumeration name> is Enumeration [Base enumeration] <Additional enumeration values> END where: - Enumeration name: Name of a previously declared enumeration.
- Base enumeration: Name of the base enumeration to be used.
- Additional enumeration values: Additional values to be taken into account in the enumeration.
Example: // Declaration code
// Declare an enumeration
RobotType is Enumération
Walk
Stopped
InMaintenance
OutOfOrder
END
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AdvancedRobotType is Enumération
[RobotType]
InLoop
END
You cannot assign extension values in a base enumeration. Creating aliases in an enumeration You can declare aliases to ensure temporary compatibility, for example. The following syntax is used: <Enumeration name> is Enumeration
<Value 1 of enumeration>
<Value 2 of enumeration>
<Value 3 of enumeration> = <Value 1 of enumeration>
END Example: // Declaration code
// Declare an enumeration
RobotType is Enumération
Walk
Stopped
InMaintenance
OutOfOrder
// Declare the temporary aliases
Maintenance = InMaintenance
Breakdown = OutOfOrder
END
Associated values In WLanguage, you can associate a simple constant value with each value of an enumeration. This value is associated with the enumeration value in the enumeration declaration. // Declare the enumeration with associated values
RobotType is Enumération
Walk = "Running the robot"
Stopped = "Robot stopped"
InMaintenance = "Robot under maintenance"
OutOfOrder = "Robot breakdown"
END
Then, it is possible to read the value associated with an Enumeration variable using the Value property. // Access to the associated value
e is RobotType
RobotMessage is string = e..Value
The associated value has no effect on other characteristics of the enumeration. For example, values are sorted in the same order as they were declared in the enumeration. Associated properties The following properties are associated with Enumeration variables: | | | Name | Gets the name of an Enumeration variable. | | Value | Gets the value of an Enumeration variable. |
Available WLanguage functions An enumeration can be stored in an HFSQL item or in another file format. Depending on your needs, you can store the enumeration name or value ( Name or Value properties, respectively). The following WLanguage functions can be used to get the characteristics of a stored enumeration:
Limitations - Enumerations are not available in dynamic compilation.
- Enumerations cannot be used outside the project.
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