Download CH6_A

Creating Custom
Forms
Part A
Eyad Alshareef
1
Data Block and Custom Forms

Data block form
Based on data blocks that are associated with
specific database tables
 Reflect the structure of the database
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Custom form
Based on control blocks that process data from
multiple tables
 Reflect business processes rather than the database
structure
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Eyad Alshareef
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Introduction to Custom Forms

Custom form
Displays data fields from variety of database tables
 Contains programs that support organizational
processes
 Use lists of values (LOVs) to retrieve data values
 Manipulate data using form triggers
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Eyad Alshareef
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Identifying the Business Processes
and Database Operations
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Identify processes that form supports
Identify associated database tables
Describe process
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Designing the Interface
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Visualize how form will look
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Creating a Custom Form

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Manually create form canvas in Object
Navigator
Create form items by “painting” items on canvas
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Using tools on Layout Editor tool palette
Write code that controls form functions
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Creating the Form Canvas
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Manually create form canvas in Object
Navigator
Start Forms Builder
Create and rename form canvas
 Rename form module and form window
 Change Title property of form window

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Perform in Visual View in Object Navigator
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Creating a Control Block

Control data block
Also called control block
 Data block not associated with particular database
table
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Create new data block in Object Navigator
Specify data block created manually
 Use Ownership View
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Creating the Form Items

Create
Boilerplate logo image and text
 Form text items
 Command button items
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Display form in Layout Editor
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Draw items on form canvas using tools in tool
palette
Eyad Alshareef
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Creating the LOVs
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LOV
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Retrieve data from database table
Use LOV Wizard
Run form
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To test LOV
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Displaying System Date and
Time Values in Form Text Items
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System variable
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Variable representing value always available to any
form
Display value in text item automatically
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Set text item’s Initial Value property
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Forms Builder Date and Time
System Variables
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Creating Command Buttons

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Create and configure buttons
Create form triggers associated with buttons
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Creating and Configuring
Command Buttons
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Draw button on canvas using Button tool
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Button tool on tool palette
Button group
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Buttons should all be same size
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Wide enough to accommodate longest button’s label
Draw button with longest label first
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Creating the Button Triggers

Select Triggers node under button in Object
Navigator
Click Create button to create trigger
 Select trigger event
 Specify trigger code
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WHEN-BUTTON-PRESSED button event
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Trigger code executes when user clicks button
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Creating the Button Triggers
(continued)
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Reference form items:

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:block_name.item_name
Clear form text items in form trigger:
Use CLEAR_FORM built-in procedure
 Create program unit to set value of text items to
blank text string
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Procedure
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Code block that executes commands to change one
or more values
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Creating the Button Triggers
(continued)

Function
Code block
 Returns single value

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Create program unit:
Open Object Navigator
 Select Program Units node
 Click Create button
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Program unit does not use DECLARE keyword
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Creating a Custom Form
1.
2.
3.
Create the form
Create the form window and canvas manually
Create a control block
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4.
Data block that is not associated with a specific table
Contains form items that you manually draw on the canvas
Create form triggers to process data
Eyad Alshareef
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Form Triggers
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Code that is associated with a form object and
an event
Can contain SQL INSERT, UPDATE,
DELETE, and SELECT commands
Referencing form text item values in triggers:
:block_name.item_name
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Practice1
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Create a custom form that has:
Employee Name
 Employee Salary
 Department Name
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Create a LOV to retrieve block records
Use triggers to retrieve block records
Create a button that calls a program unit to clear
the block.
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Creating a custom form

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Create a new form module and name it COURSE
Click on data bloc and then on the plus icon. Select
Build a data block manually
Rename your block into COURSE_BLOCK
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Create and modify a canvas
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Add a canvas by clicking on Canvas in object navigator
and then on a plus sign
Rename your canvas into HEADER, and open it with
Design Editor
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Create and modify a canvas

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Change the background color of the canvas using the
Property palette
Add a header “Course Information”
Add a picture (download any picture from the web, save
in in C:\\temp, then go to Edit, Import)
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Add text boxes and prompts
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Using the toolbox on the left, add Course Name text
box and a corresponding prompt:
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Add text boxes and prompts
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Using the toolbox, add a stacked canvas on COURSE canvas
Name your canvas COURSE_ITEMS
Add Room and Time text boxes and corresponding prompts to
the COURSE_ITEMS canvas
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Add control buttons
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Return to the main canvas
Using toolbox on the left, add four control buttons.
Name them New, Find, Save and Clear
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Adding PL/SQL code
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Create triggers for each of the buttons
Add PL/SQL code to the triggers
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Adding PL/SQL code
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Adding PL/SQL code
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Create triggers for each of the buttons
Add PL/SQL code to the triggers
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Adding PL/SQL code
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Create triggers for each of the buttons
Add PL/SQL code to the triggers
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Adding PL/SQL code
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Create triggers for each of the buttons
Add PL/SQL code to the triggers
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Form Trigger Properties
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Trigger activated
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In response to event such as clicking button
Trigger name defines event that activates it
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Trigger Categories
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Trigger Timing
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Specifies when trigger fires
PRE
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POST
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Fire just before event successfully completes
Fire just after event successfully completes
ON-,WHEN-, and KEY
Fire in response to actions
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Trigger Scope
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Defines where event must occur in order for
associated trigger to fire
Includes object to which trigger attached
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And objects within trigger object
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Trigger Execution Hierarchy
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Defines which trigger fires
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When object within form object contains same
trigger that form object contains
By default trigger in higher-level object overrides
trigger in lower-level object
Can specify custom execution hierarchy
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Directing Form External
Navigation
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External navigation
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Form focus
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User causes form focus to change by making
different form item active
Item currently selected on form
Internal navigation
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Result of internal form code that responds to
external navigation operations or trigger commands
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Setting the Form Tab Order
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Set tab order
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Place items in correct order under Items node
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In Object Navigator window
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Directing External Navigation
Using Built-in Subprograms
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Built-in subprograms
Called built-ins
 Use to direct external form navigation
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Cannot use in navigational triggers
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Built-in Subprograms to Control
External Navigation
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Triggers That Fire at
Form Startup
Triggers Fired
User Action
1
2
PRE-FORM
PRE-BLOCK
User starts form
4
Result on User
Screen Display
3
Form appears,
but with no
data visible
5
WHEN-NEW-FORM-INSTANCE
WHEN-NEW-BLOCK-INSTANCE
WHEN-NEW-RECORD-INSTANCE
WHEN-NEW-ITEM-INSTANCE
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Form is
available for use
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Triggers That Fire as a Result
Of External Navigation
User Action
User places the
insertion point
in a text item
User clicks
the Next Record
button
Triggers Fired
WHEN-NEW-ITEM-INSTANCE
WHEN-NEW-RECORD-INSTANCE
WHEN-NEW-ITEM-INSTANCE
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Result on User
Screen Display
Insertion point
appears in item
Next record
appears
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Triggers That Fire When a
Form Closes
User Action
User closes
the Forms
Runtime window
Triggers Fired
POST-BLOCK
POST-FORM
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Result on User
Screen Display
Forms Runtime
window closes
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