Users Guide
Working with Structures

When you define a structure, you are defining a new datatype. You can use this new datatype in scripts and user-defined functions as long as the structure definition is stored in a library in the application's library search path.

Referencing global structures

The variables in a structure are similar to the properties of a PowerBuilder object. To reference a global structure's variable, use dot notation:

structure.variable

Example. Assume that s_empdata is a global structure with the variables emp_id, emp_dept, emp_fname, emp_lname, and emp_salary. To use this structure definition, declare a variable of type s_empdata and use dot notation to reference the structure's variables, as shown in the following script:

s_empdata   lstr_emp1, lstr_emp2 // Declare 2 variables
                             // of type emp_data.

lstr_emp1.emp_id = 100       // Assign values to the
lstr_emp1.emp_dept = 200     // structure variables.
lstr_emp1.emp_fname = "John"
lstr_emp1.emp_lname = "Paul-Jones"
lstr_emp1.emp_salary = 99908.23

// Retrieve the value of a structure variable.
lstr_emp2.emp_salary = lstr_emp1.emp_salary * 1.05

// Use a structure variable in a
// PowerScript function.
MessageBox ("New Salary", &
   String(lstr_emp2.emp_salary,"$###,##0.00"))

Referencing object-level structures

You reference object-level structures in scripts for the object itself exactly as you do global structures: declare a variable of the structure type, then use dot notation:

structure.variable

Example. Assume that the structure str_custdata is defined for the window w_history and you are writing a script for a CommandButton in the window. To use the structure definition in the script, you write:

str_custdata lstr_cust1
lstr_cust1.name = "Joe"

PowerBuilder copies all the variable values from struct2 to struct1.

Example. These statements copy the values in lstr_emp2 to lstr_emp1:

str_empdata lstr_emp1, lstr_emp2
...
lstr_emp1 = lstr_emp2

You can pass structures as arguments in user-defined functions. Simply name the structure as the datatype when defining the argument.Similarly, user-defined functions can return structures. Name the structure as the return type for the function.

You can also define external functions that take structures as arguments.

Example. Assume the following:

You can call the function as follows:

Revise(lstr_empdata)

For more about passing arguments to external functions, see the section called “Passing arguments” in Application Techniques.

You can display the names and variables of defined structures in the Browser. You can also paste these entries into a script.