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  • Declaring structures
  • Type of structure members
  • Declaring an array member in a structure
  • Homonymic copy of a structure
  • Serializing the members of a structure
  • Which "advanced" types can be a member?
  • Passing a structure as a parameter to a procedure
  • Adding the content of a structure to an array of structures without using a variable of the structure
  • Limits of a structure
  • Differences between version 8 and version 9
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Stored procedures
A structure is a custom type of data. A structure groups different types of elements.
Remark: If you are handling custom variables, we advise you to declare:
  • a structure type if several variables of this type are used in different processes of the project.
  • a composite variable if a single variable of this type is used in your project (to pass parameters to an API for example).
Example
// Declare a structure
ProductRef is Structure
SCode is int
PdtCode is fixed string on 10
END
// Declare a structure variable
ProductRef is Structure
SCode is int
PdtCode is fixed string on 10
END
Armchair is ProductRef
// Handle a member of a structure variable
ProductRef is Structure
SCode is int
PdtCode is fixed string on 10
END
Armchair is ProductRef
Armchair:SCode = 7
Armchair:PdtCode = "Furniture"
// Declare and initialize the members of a structure
3dPoint is Structure
x is int
y is int
z is int
END
 
p1 is 3dPoint = [0, 0, 50]
Syntax

Declaring a structure Hide the details

<Structure name> is structure
   <Structure members>
END
<Structure name>:
Name of structure to declare
<Structure members>:
Declarations of variables found in the structure. These variables are called members of the composite variable.
When declaring the members of the structure, you have the ability to specify the serialization parameters of these members. For more details, see "Serializing the members of a structure".
<END>:
End of variable declaration.

Declaring a structure variable Hide the details

<Variable name> is <Structure name>
<Variable name>:
Name of the structure variable to declare.
<Structure name>:
Name of a structure that was declared beforehand.

Handling a member of a structure variable Hide the details

<Name of structure variable>:<Name of structure member>
<Name of structure variable>:
Name of the structure variable to use.
<Name of structure member>:
Name of the structure member to use.
The members of a structure variable can be assigned via the multiple assignment.
Remarks

Declaring structures

If a <Structure name> structure is declared:
  • in the project code, a <Structure name> variable can be declared in the entire project.
  • in the declaration code of the global variables of a window, a <Structure name> variable can be declared in the window, in its controls and in its associated local procedures.
  • in the opening code of a report, a <Structure name> variable can be declared in the report, in its controls and in the associated local procedures.
  • in the declaration code of a class, a <Structure name> variable can be declared in the class and in its methods. Caution: "Is structure" must necessarily be positioned before "is class".
  • in a process/i>, a <Structure name> variable can be declared in the process.
JavaPHP The structure must be declared in the declaration process of global variables (of a window, page or set of procedures).
WEBDEV - Server codeWEBDEV - Browser code Remarks:
  • A structure variable can be declared in browser code from a structure declared in server code or in browser code.
  • If a structure variable is declared in browser code from a structure declared in server code, the server structure must be made of simple types: string, integer, real, boolean, date and time.

Type of structure members

The members of a structure can have the following types:
Any other type of data (composite variable, constant, ...) is forbidden.
WEBDEV - Browser code A structure declared in browser code must be made of simple types: string, integer, real, boolean, date and time.

Declaring an array member in a structure

  • Declaring a member whose type is simple array:
    The array dimensions are fixed when the array is declared. The array dimensions can be modified by Dimension.
  • Declaring a dynamic array member:
    The array dimensions must be defined (which means that the array must be allocated) before using the array. For example:
    // Declare a structure
    Struct is Structure
    x1 is int
    x2 is dynamic array        // Declare the array
    END
     
    // Declare a structure variable
    MyStruct is Struct
     
    // Allocate the array
    MyStruct.x2 = new dynamic array of 4,7 int
    // Use the array
    MyStruct:x2[1,1] = 25
  • Homonymic copy of a structure

    The => operator is used to perform an homonymic copy of a structure variable.
    This homonymic copy can also be performed by using the = operator.
    Caution, the copy is performed member to member: only the members with same names will be copied. The members with different or non-existing names will be ignored.
    Example:
    // Declare a structure
    StructImportCustomer is Structure
    LastName is string
    FirstName is string
    Company is string
    Address is string
    ZC is string
    City is string
    END
     
    StructInternalCustomer is Structure
    LastName is string
    FirstName is string
    Company is string
    Address is string
    FullAddress is string
    ZC is string
    City is string
    Country is string
    END
     
     
    NewCustomer is StructImportCustomer
     
    CurrentCustomer is StructInternalCustomer
     
    CurrentCustomer = NewCustomer // the FullAddress and Country members are not filled

    Serializing the members of a structure

    By default, all the members of a structure are serialized.
    You have the ability to precisely manage the serialization of each member of a structure:
    • by specifying the member that will be serialized during the call to Serialize.
      This operation can be performed on all types of serialization (WXML, JSON, binary).
    • by changing the name of the member during the serialization with Serialize.
      This operation can be performed during a binary serialization only.
    This management of serialization is performed by using the following syntax:
    • Serialization (or not) of a member:
      <Member name> is <Type of member> [, Serialize = <True/False>]
    • Serialization and change of member name:
      <Member name> is <Type of member> [, Serialize = <New name>]
    Example:
    Cl is Structure
    // Serialized member
    SerializedMember is int
    // Non-serialized member
    NonSerializedMember is string, Serialize = false  
    // Member renamed during the serialization
    RenamedMember is int, Serialize = "NewMemberName"
    END

    Which "advanced" types can be a member?

    An "advanced" variable can be a member of another "advanced" variable. The table below presents the different combinations:
    Composite variableStructureClassArray
    Composite variableNoNoNoNo
    StructureYesYesYesYes
    ClassYesYesYesYes
    ArrayYesYesYesNo

    Passing a structure as a parameter to a procedure

    A "structure" variable can be passed as a parameter to a procedure. To do so, use the following syntax:
    <Procedure name>(<Name of structure variable>)
    For example:
    ProductRef is Structure
    SCode is int
    PdtCode is fixed string on 10
    END
    Armchair is ProductRef
     
    // Call the DisplayProduct procedure
    DisplayProduct(Armchair)

    Adding the content of a structure to an array of structures without using a variable of the structure

    If you are using an array of structures with few members, it may be easier to directly add a structure by using the [ ] operator (square brackets).
    For example, for the following structure:
    // Structure to store a letter and its ASCII code
    STKey is Structure
    sKey is string
    nAsciiCode is int
    END
    // Array of structures
    arrKeys is array of STKey

    In most cases, content is added by using a variable of a type declared in the structure:
    // Temporary structure for the addition
    stAKey is STKey
    // Stores the letter A
    stAKey.sKey = "A"
    stAKey.nAsciiCode = Asc("A")
    arrKeys.Add(stAKey)

    With the [ ] operator, you get better legibility:
    // Stores the letter A
    arrKeys.Add(["A", Asc("A")])

    Limits of a structure

    • The inheritance of structure is not allowed: a structure cannot inherit from another structure.
    • The access to a member of a structure cannot be restricted: all the members of a structure are public.
    WINDEVWEBDEV - Server codeJava

    Differences between version 8 and version 9

    A structure containing a character member has not the same behavior as in the earlier versions. Indeed, the characters were coded on 1 byte in version 8 and on 2 bytes in version 9.
    We recommend that you use the "1-byte integer" type.
    Minimum version required
    • Version 9
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