HP 3000 Manuals HP 3000 Manuals
Calculated Items A calculated item is a special type of variable. A calculated item implicitly refers to a function. When HP ALLBASE/4GL encounters a reference to a calculated item, it automatically executes the function to determine the value of the calculated item. A calculated item can be defined as a single CALC command, or it may be extended to use as many lines of logic in the function as you require. Menu Path To access the calculated items screen: 1. From the main menu, select the Dictionary option. 2. Select the Storage Items option. 3. Choose Calculated Items. Screen Description This screen allows you to define a calculated item. You will define the item's basic characteristics and a single CALC statement to derive the value of the calculated item. Defining a calculated item automatically creates a function of the same name. This function is automatically executed each time the item is accessed. If the item you are defining requires more than a single CALC statement, you can subsequently call up the function in the function details screen. A calculated item defined this way is known as an extended calculated item. The screen below shows the completed screen after defining a calculated item for the KSAM version of the application.Calculated Items Screen To enter the field values: Field Entry Explanation --------------------------------------------------------------------------------------- Item Name option_cost This is the name of the calculated item that you are defining. HP ALLBASE/4GL automatically creates a function with the same name for the necessary logic that is needed behind the item. Even if the calculated item only requires one line of logic to calculate its value, HP ALLBASE/4GL still creates the function. A calculated item cannot have the same name as an existing function in the same application. Length 12 The length of the calculated item can be up to 99 characters. Edit Code N This is a standard edit code. Number of Decimal 2 This specifies the maximum number of Places decimal places assigned to the item. It is only relevant for numeric fields. Pad Character Leave blank. As for variables, alphanumeric calculated items are left justified and numeric items are right justified. The pad character entered here replaces any leading or trailing spaces remaining as a result of the justification. Field Entry Explanation --------------------------------------------------------------------------------------- The CALC For KSAM based and HP When you leave the pad character field you command TurboIMAGE/iX based will see that the word CALC is displayed to applications, enter: the left of the input area occupied by the cursor. This input area allows you to F-cost.option x enter the statement to calculate the value F-quantity.option = of the item. Refer to the HP ALLBASE/4GL U-option_cost Developer Reference Manual for further details about the CALC command. For HP ALLBASE/SQL based applications, enter: Note that the destination of the CALC command is the calculated item itself. F-cost.prod_opt x This is how a value is assigned to a F-quantity.prod_opt = calculated item. U-option_cost Note If you extend a calculated item, you can use any logic block commands including a visit to another function. However, the only function that can assign a value to a calculated item is the function with the same name as the calculated item. If you attempt to assign a value to a calculated item from any other source, the application will abort at run-time. If you don't want to use a CALC statement, or wish to extend this function you can leave the CALC statement blank. You can then define the logic for the item by calling up the function with the function details screen. Description Enter a suitable description. To complete the entries: 1. Press the Commit Data function key when you have finished creating the calculated item. A calculated item automatically creates a function of the same name. Pressing the Commit Data function key generates the function automatically. If any errors occur during the generation operation, they are displayed in the normal way. Correct any errors using either the calculated item screen or the function details screen. You may wish to examine the logic block created by the CALC item by looking at it using the function details screen. Generating the Report Once you have defined the calculated item, generate the prod_opt report. Now you will need to alter the main menu so that you can execute the report. Altering the Main Menu This is what the main menu will look like when you have repainted it.Repainted Main Menu To alter the main menu: 1. Call up the main menu in the screen painter. 2. Add the following action item to the screen. Where you place it on the screen is up to you. The screen image above is one suggested format for the menu. Type Name Text R (report) prod_opt Stock Report 3. When you have defined this item, exit from the painter. HP ALLBASE/4GL saves the menu as you exit. Running the Report When you have altered the main menu, you may run your application and test the report. You defined that the report printer destination was printer 1. Ask your HP ALLBASE/4GL administrator what has been defined as printer 1 for your system, or, if you have access to the administ application, you may check for yourself by selecting System Specifications on the main menu, and then System Definition on the System-Wide Specifications menu. This displays the System Definition screen, which lists the printers defined for HP ALLBASE/4GL. The training application is now functionally complete.
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