The Fundamentals of Frame SCL

Typical frame SCL code consists of the following:

An SCL labeled section is a set of programming statements that execute as a unit. A section in SCL begins with a label and ends with a RETURN statement.

Sections that are labeled with the name of a control on the associated frame execute when the user interacts with that control. For example, if you have a Push Button named exitButton on your frame, and you want to use it to confirm that the user wants to exit the application, you might have a labeled section similar to the following in your frame SCL:

   exitButton:
      dcl list message={'Are you sure you want to exit?'};
      response=messagebox(message, '!', 'YN', 'Confirm Exit', 'N', '');
      if response='YES' then call execcmd('end;');
      message=dellist(message);
   return;

The code in the exitButton section executes when that exitButton is clicked, resulting in a dialog box to confirm the exit.

Section labels do not have to match the casing of the name of the control to which they are associated.

Frame SCL uses reserved sections for program initialization and termination (there is also a main processing section, but that is not covered in this document). The INIT section executes once before the frame is displayed to the user, and is typically used to initialize variables and open SAS tables. The TERM section executes once before the frame is closed, and is typically used to close tables and delete variables that are no longer needed. You should always delete lists when they are no longer needed.

Here are example INIT and TERM sections:

INIT:
    dcl num variable1 rc;  /* Declares two numeric variables. */
    dcl list myList={};    /* Declares an empty list.         */
return;

TERM:
    rc=dellist(myList);  /* Deletes the list myList. */
return;

Each variable that is used in SCL is of a specific data type. The following SCL data types are used in the example application later in this document:

All variables should be declared using a DECLARE statement. DECLARE statements do not have to exist in labeled sections. You can declare several variables with one DECLARE statement. You can also use the abbreviation DCL.

CHAR, NUM, and LIST are reserved keywords that indicate the data type of the variables.

CHAR(n) is a notation that enables you to define the length of a character variable, where 'n' is the length in characters, a value up to 32767. By default, character variables are 200 characters long. Consider the following code:

DECLARE  NUM      n1 n2,     /* Two numeric variables.                */
         CHAR     c1,        /* A character variable with length 200. */
         CHAR(10) c2,        /* A character variable with length 10.  */
         LIST     myList={}; /* An empty SCL list.                    */

SCL provides a rich set of routines and functions that, for example, enable you to inspect and manipulate SAS catalogs, SAS tables, and the controls on a frame. For detailed information about these functions, refer to SAS Component Language 9.4: Reference.

SCL also supports nearly all of the functions of the Base SAS language. For details about the Base SAS functions, see the SAS 9.4 Functions and CALL Routines: Reference.