stacked canvas a content canvas is a main from canvas while a stacked canvas is a secondary canvas...
TRANSCRIPT
Stacked Canvas
A content canvas is a main from canvas while a stacked canvas is a secondary canvas that overlays or partially covers a content canvas. In other words, it can be stacked on another canvas.
Thus in this slide presentation a content canvas will be made first, followed by a stacked canvas.
Open a new Form Module
Create a new data block using the
EMPLOYEE table
Use a new Content canvas
Set these prompts
The layout style should be Form
Display only on record and title the frame Employee Details
The Employee Details frame
Open the Property Palette for EMPLOYEE NUMBER
Change the required property to No
Highlight the Module and create a new data block for the EMPLOYEETYPE table
Deselect Auto-join. This data block should not be related to EMPLOYEE
Place this data block on a new stacked canvas
Use these prompts
Select the Form layout
Only display one record
Use the Frame Title, Employee Type Details
The canvas for Employee Type Details
In the Layout Editor, resize this stacked canvas to the Following:
Height 75Width 410
The canvas has been resized
Notice the size of the canvas
Change the name of the Content Canvas to
EMPLOYEES
Change the name of the Stacked Canvas to
EMPLOYEE_TYPE
Name changes can be done in the Property Palette or on the Object Navigator. In using the Object Navigator, highlight the object to
be changed. Ensure that the highlight is blue, not yellow, and change the name.
The names have been changed
Highlight the form window, WINDOW1. Open the Property
Palette and set these properties:Name: PRINCIPAL_WINDOWTitle: EMPLOYEE CHANGE FORMPrimary Canvas: EMPLOYEES
Properties changed
The window is now called
PRINCIPAL_WINDOW
Highlight Windows and create a new window
by clicking Edit, Create
The new window, WINDOW11 has been created. Open the Property Palette and set these properties:
Name: EMPLOYEE_TYPETitle: ADD NEW TYPEPrimary Canvas: EMPLOYEE_TYPE
Properties changed
For the EMPLOYEE_TYPE window, set these additional properties:
X Position: 20Y Position: 50Width: 410Height :75
Properties changed
Open the Property Palette for the
EMPLOYEE_TYPE canvas
Change the window to EMPLOYEE_TYPE
Locate the EMPLOYEETYPE item in the EMPLOYEE data
block and create a When-Validate-Item
trigger
Enter this source code for
the triggerFor the explanation of %ROWTYPE see the
next slide
%ROWTYPE Attribute
The %ROWTYPE attribute provides a record type that represents a row in a database table. The record can store an entire row of data selected from the table or fetched from a cursor or cursor variable. Variables declared using &ROWTYPE are treated like those declared using a datatype name.
%ROWTYPE can include all the columns in a table:
emp_rec employee%ROWTYPE;
Or a subset of the columns, based on a cursor:
CURSOR XYZ IS
SELECT DepartmentNumber, DepartmentName FROM departments;
Dept_rec XYZ%ROWTYPE;
Columns in such rows have the same names and datatypes, but do not inherit constraints such as NOT NULL or default values.
Open the Layout Editor for
EMPLOYEE
Add a button next to Emp. Type
Push Button has been added. Open the property Palette and give it the following properties:Name: ADD_TYPELabel: ADD TYPE
Properties changed
Name changed
Create a When-Button-Pressed trigger for the ADD_TYPE item. With Triggers highlighted, click Edit,
Create
Enter this code
Go_block navigates to the indicated data block. If the
target block is non-enterable, an error occurs. The syntax:
Go-block (‘Block Name’);
Open the Property Palette for the data block EMPLOYEETYPE. Set the following properties:
Update Allowed: NoDelete Allowed: NoQuery Allowed: No
1. Compile and run the form. Enter Ctrl-F11 to enter data on
the form. You must be connected to the database!
2. Enter an invalid Emp. Type
3. This warning is given
Change the Emp. Type back to its original value and click the
ADD TYPE button
The stacked canvas, ‘Employee Type Details’ appears on the top of the content canvas,
‘Employee Details’.
Notice that there are two windows:1. EMPLOYEE CHANGE FORM2. ADD NEW TYPEThe ADD NEW TYPE window is the active window.
1. Enter a new Emp. Type as shown
2. Click Insert record3. Click Save
4. A new record will have been added to
the database
A new record has been added to
EMPLOYEETYPE