Oracle Forms Q&A , Part 1

FAQs in Oracle Forms – Part:1

What are different types of modules available in oracle form?

Form module – a collection of objects and code routines.

Menu module – a collection of menus and menu item commands that together make up an application menu.

Library module – a collection of user named procedures, functions and packages that can be called from other modules in the application.

What are the default extensions of the files created by forms modules?

.fmb – form module binary

.fmx – form module executable

What are the default extensions of the files created by menu module?

.mmb, .mmx

What is data block & control block?

Data Block:-It is a Logical Collection of Items.
Control Block:-It is a data block which is totally independent of Database Table or View.

Note: – A data block can have control block items but not vice versa.

What is property class & visual attributes?

Property Class:

A property class is a named object that contains a list of properties and their settings. Once you create a property class you can base other objects on it. An object based on a property class can inherit the setting of any property in the class that makes sense for that object. Property class inheritance is an instance of subclassing. Conceptually, you can consider a property class as a universal subclassing parent.

Visual Attributes:

Visual attributes are the font, color, and pattern properties that you set for form and menu objects that appear in your application’s interface. Visual attributes can include the following properties: Font properties: Font Name, Font Size, Font Style, Font Width, Font Weight Color and pattern properties: Foreground Color, Background Color, Fill Pattern. Every interface object has a Visual Attribute Group property that determines how the object’s individual visual attribute settings (Font Size, Foreground Color, etc.) are derived. The Visual Attribute Group property can be set to Default, NULL, or the name of a named visual attribute defined in the same module.

What is the difference between property class and visual attribute?

We can change Visual Attribute properties dynamically at runtime, but we cannot change Property class properties. When you inherit the both Visual Attribute properties and Property class properties to an item Visual Attribute properties overrides the Property class properties.

What is object group?

An object group is a container for a group of objects. You define an object group when you want to package related objects so you can copy or subclass them in another module. Object groups provide a way to bundle objects into higher-level building blocks that can be used in other parts of an application and in subsequent development projects.

What is Record Group?

It is an internal memory data structure and a separate object in the form module. It’s main usage is to provide data to the LOV and dynamically to the list item and to perform client level validations.

What are the types of Record-Groups?

Static Record Group:- A static record group is not associated with a query; instead, you define its structure and row values at design time, and they remain fixed at runtime. Static record groups can be created and modified only at design time.

Query Based Record Group: – A query record group is a record group that has an associated SELECT statement. The columns in a query record group derive their default names, data types, and lengths from the database columns referenced in the SELECT statement. The records in a query record group are the rows retrieved by the query associated with that record group.

Non Query Record Group:- A non-query record group is a group that does not have an associated query, but whose structure and values can be modified programmatically at runtime. Non-query record groups can be created and modified only at runtime.

How to change Record Group dynamically?

By Using Non-Query Record Group.

What is Library?

A library is a collection of subprograms, including user-named procedures, functions, and packages. We can attach a library to any other form, menu or library module. It provides an easy method of reusing objects and enforcing standards across the entire development organization.

What are the types of canvases available in forms & what is the default canvas?

Content:-it is the base view of window which occupies the entire surface of window. It can have any no of canvases but at a time only one is visible.

Stacked:-It is always displayed above the content canvas because the content Canvas is the base view. It can have any no of stacked canvases and more than one stacked canvas can be displayed at a time.

Tool bar:- A toolbar canvas often is used to create toolbars for individual windows. There are two types of tool bars Horizontal and Vertical Tool bar Canvas. Horizontal tool bar canvases are displayed at the top of window and only one horizontal tool bar can be attached to a form module. Vertical tool bar is used to display top to bottom on the left side of the window.

Tab:-It is a collection of one or more tab pages. It is mainly used to display a large amount of related information a single dynamic form builder canvas object.

Content Canvas is the default canvas.

What are Alerts?

An alert is a modal window that displays a message notifying the operator of some application condition. There are three styles of alerts: Stop, Caution, and Note.
To display an alert, your application must execute the SHOW_ALERT built-in subprogram from a trigger or user-named subprogram. SHOW_ALERT is a function that returns a numeric constant.

Show_Alert(alert_name) Return NUMBER;

What are LOVs?

An LOV is a scrollable popup window that provides the end user with either a single or multi-column selection list. LOV values are derived from record groups. The LOVs in the Form Builder interface have the same auto-reduction and searching functionality as the LOVs you create for your own applications.

There are two built-in subprograms that can be used to display an LOV:
1) LIST_VALUES
2) SHOW_LOV

List the system variables related in Block and Field?

1. System.block_status

2. System.current_block

3. System.current_field

4. System.current_value

5. System.cursor_block

6. System.cursor_field

7. System.field_status

What is a master detail relationship?

A master detail relationship is an association between two base table blocks- a master block and a detail block. The relationship between the blocks reflects a primary key to foreign key relationship between the tables on which the blocks are based.

What are the Various Master and Detail Relationships?

The various Master and Detail Relationship are:

a) NonIsolated :: The Master cannot be deleted when a child is existing.

b) Isolated :: The Master can be deleted when the child is existing.

c) Cascading :: The child gets deleted when the Master is deleted.

What are the procedures that will be created when a master details form created?

CHECK_PACKAGE_FAILURE
CHECK_ALL_MASTER_DETAILS
QUERY_MASTER_DETAILS

What is mouse navigate property of button?

When Mouse Navigate is True (the default), Oracle Forms performs standard navigation to move the focus to the item when the operator activates the item with the mouse. When Mouse Navigate is set to False, Oracle Forms does not perform navigation (and the resulting validation) to move to the item when an operator activates the item with the mouse.

What is difference between PL/SQL library and object library in Forms?

PL/SQL library contains only pl/sql codes which can be used for standardizing the validations etc. in forms whereas Object Library is used to create, store, maintain, and distribute standard and reusable Form objects.

What are the different default triggers created when Master Deletes Property is set to Nonisolated?

On-Check-Delete-Master

On-Clear-Details

On-Populate-Details

What are the different default triggers created when Master Deletes Property is set to Cascade?

On-Clear-Details

On-Populate-Details

Pre-delete

What are the different default triggers created when Master Deletes Property is set to isolated?

On-Clear-Details

On-Populate-Details

What is the difference between SHOW_EDITOR and EDIT_TEXTITEM?

Show_editor is the generic built-in which accepts any editor name and takes some input string and returns modified output string. Whereas the edit_textitem built-in needs the input focus to be in the text item before the built-in is executed.

What is the “LOV of Validation” Property of an item? What is the use of it?

When LOV for Validation is set to True, Oracle Forms compares the current value of the text item to the values in the first column displayed in the LOV whenever the validation event occurs. If the value in the text item matches one of the values in the first column of the LOV, validation succeeds, the LOV is not displayed, and processing continues normally. If the value in the text item does not match one of the values in the first column of the LOV, Oracle Forms displays the LOV and uses the text item value as the search criteria to automatically reduce the list.