1 Chapter 12: Form Builder Objects and Flexible Code

2 Object-Oriented Principles Object Abstract representation of something in the real world Class Group of objects with the same structure and properties Class instance Object that belongs to a specific class Inheritance Specifies that when you create a new object, it inherits its structure and properties from its class

3 Subclasses Classes that have similar properties and structure of their parent class Subclasses have specializations, which are properties that make them different than their parent class

4 Form Builder Approaches For Creating Reusable Objects Property Classes Object Groups Object Libraries PL/SQL Libraries

5 Property Classes Top-level Form Builder objects that specify a collection of properties with specific values Property classes can be associated with Form Builder objects to define object properties

6 Creating a Property Class Approaches: Create the property class based on an existing object Explicitly create the property class object, and then define its properties and associated values

7 Creating a Property Class Based on an Existing Object Create the object and configure its properties as desired In the object’s Property Palette, select the desired properties and then click the Property Class button on the toolbar to create the property class

8 Creating a Property Class Explicitly Create the property class object in the Object Navigator and open its Property Palette To add a property, click the Add Property button To remove a property, select the property and then click the Remove Property button

9 Using Property Classes to Subclass Form Objects When you apply a property class to a form object, the form object is subclassed to the property class To subclass a form object, open the object’s Property Palette, and the the property class name in the Subclass Information dialog box

10 Using the Subclass Information Dialog box Select whether you are subclassing from an object or a property class Select the property class name

11 Object Groups Top-level form objects that contain groups of objects that can be reused in different forms Examples of object types in object groups: LOVs Data blocks Alerts Object groups are created in a source from, and then subclassed into target forms

12 Creating an Object Group Create a new object group object in the form template Rename the object group

13 Adding Objects to an Object Group Create the objects Drag and drop the objects on the object group Object Group Children node

14 Subclassing Object Groups in Target Forms Select the object group in the source form Drag the object group to the Object Groups node in the target form, drop the object group, and click the Subclass button

15 Subclassing vs. Copying Objects When you subclass an object, changes to original object are propagated to subclassed objects When you copy an object, changes to original object do not affect subclassed objects

16 Form With Objects Subclassed From Object Group Subclassed object group Subclassed objects

17 Object Libraries Top-level Form Builder objects that are independent of specific forms Contain form objects that can be referenced in specific forms

18 Creating an Object Library Create a new object library object in Form Builder Save the object library file File has an.olb extension Filename specifies object library name

19 Object Library Structure Consists of multiple library tabs Tab pages that contain one or more similar object instances

20 Creating and Configuring Tab Pages To create a new tab page, select the Library Tabs node, and then click the Create button Right-click the new tab page, and then click Property Palette to open the tab page Property Palette Change the tab page Name and Label values

21 Opening the Object Library Double-click the object library icon to open the Object Library window Library tabs Object on tab page

22 Adding Form Objects to Library Tab Pages Create and configure the object in a source form Open the source form Object Navigator and the Object Library window side-by-side Maximize the Object Navigator window Open the Object Library window, and then click the Restore button so the Object Library appears in a window Reposition the windows as necessary Drag and drop the object onto the Library Tab page

23 Window Configuration For Adding Objects Object Navigator window Object Library window Object to be stored in library

24 Using Object Library Objects in Forms Open the target form Object Navigator and the Object Library window side-by- side Drag and drop the object library object into the target form Subclass the object into the target form

25 SmartClasses Object library objects that are defined as standard object types for an application SmartClassed objects appear as selections on a pop-up menu when you create a new object and then right-click the object Speeds up the process of using object libraries

26 Creating a SmartClass Select the object in the object library Click Object on the menu bar, and then click SmartClass Green check indicates object is a SmartClass

27 Selecting a SmartClass

28 PL/SQL Libraries Library of PL/SQL named program units that can be used in forms Top-level Form Builder object that is not associated with a specific form Specific program units can be attached to forms Code is not part of form.fmb file Code is only loaded when program unit is called

29 Creating a PL/SQL Library in Form Builder Select the PL/SQL Libraries node, and then click the Create button Save the library in the file system Library name is the same as the filename File has a.pll extension

30 Saving PL/SQL Library Files In general, PL/SQL library files should be saved in the default PL/SQL library folder Path: Developer_Home\TOOLS\OPEN60 If you save a library file in a different location, that path and file must always be available when you open forms that reference the library

31 Adding Program Units to PL/SQL Libraries Select the library Program Units node, and then click the Create button Select the named program unit type (procedure, function, package) Type the program unit code in the PL/SQL Editor window

32 Using PL/SQL Libraries in Forms Attach the library to the form Call the library program units from form triggers

33 Attaching a PL/SQL Library to a Form Select the form’s Attached Libraries node, and then click the Create button Navigate to the library file and attach the file If the library is saved in the default library folder, click Yes to discard path information If the library is not saved in the default library folder, click No to save path information

34 Calling a Library Program Unit From a Form Trigger Reference the program unit and pass the required parameters as specified in the attached library specification in the Object Navigator

35 Calendar Windows Associated with a form text item that displays date values Allows the user to select a date The selected date value is returned to the form text item

36 Creating a Calendar Window Open the STNDRD20.OLB object library and copy or subclass the Calendar object group into the form Attach the CALENDAR.PLL PL/SQL library to the form Create a trigger associated with the form text item that calls a procedure in the CALENDAR.PLL PL/SQL library

37 Subclassing the Calendar Object Group Into the Form Open the target form Open the STNDRD20.OLB object library Subclass the CALENDAR object group into the target form

38 Subclassing the Calendar Object Group Into the Form

39 Attaching the CALENDAR.PLL PL/SQL Library to the Form Create a new attached library object in the target form Click Browser, select CALENDAR.PLL, click Open, and then click Attach to attach the library

40 Creating a Trigger to Open the Calendar Window Create a Show Calendar button next to the date text item Create the trigger to call the GET_DATE procedure in the DATE_LOV package

41 Creating a Trigger to Open the Calendar Window

42 Flexible Code Allows you to create objects that can be configured at runtime Approaches Use system variables to retrieve and set system values Use built-in subprograms that dynamically retrieve and set form object properties

43 Using Built-in Subprograms to Create Flexible Code GET_ built-ins Allow you to retrieve current object properties SET_ built-ins Allow you to dynamically set object properties

44 GET_APPLICATION_PROPERTY Built-in Returns information about the current Form Builder application Syntax: GET_APPLICATION_PROPERTY(property_name);

45 Retrieving Specific Object Properties Syntax: return_value := GET_object_PROPERTY (object_id | ‘object_name’, property_name);

46 Retrieving Object ID Values Using the FIND_ Built-ins Syntax: return_value := FIND_object(‘object_name’);

47 Dynamically Setting Object Properties Syntax: SET_object_PROPERTY(object_id | ‘object_name’, property_name, property_value);

48 Using Indirect Referencing to Write Flexible Code Direct referencing Directly referencing a form object using the format :block_name.object_name Indirect referencing Specifying block and item names in single quotation marks Allows you to reference objects that are not in the current form

49 Commands For Indirect Referencing COPY Indirectly sets the value of a form item Syntax: COPY(value, ‘destination’);  Value: desired value  Destination: form item  Format: block_name.item_name

50 Commands For Indirect Referencing NAME_IN Indirectly retrieves the value of a form item Syntax: return_value := NAME_IN(source);  Return_value: retrieved value  Is always a character string  Source: form item  Format: block_name.item_name