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A custom VISUAL user object is an object that has several controls that work as a unit. A standard visual user object INHERITS its definition from a standard CONTROL. We modify the definition to make the control specific to our APPLICATIONS.

A custom visual user object is an object that has several controls that work as a unit. A standard visual user object inherits its definition from a standard control. We modify the definition to make the control specific to our applications.

CONSTRUCTOR and DESTRUCTOR

Constructor and Destructor

By USING FUNCTIONS : OpenUserObject( ), OpenUserObjectWithParm( )

By using functions : OpenUserObject( ), OpenUserObjectWithParm( )

OpenUserObject() adds a user object to the SPECIFIED WINDOW and makes all its properties and CONTROLS available to scripts. windowname.OpenUserObject ( userobjectvar, userobjecttype {, x, y } ) This function is USED when you want dynamically, at runtime place some user objects on a window. This function displays this user object, makes all its attributes available to scripts. You MUST open a user object before you can access the attributes of the user object. If you access the user object’s attributes before you open it, it will cause an execution error.

OpenUserObject() adds a user object to the specified window and makes all its properties and controls available to scripts. windowname.OpenUserObject ( userobjectvar, userobjecttype {, x, y } ) This function is used when you want dynamically, at runtime place some user objects on a window. This function displays this user object, makes all its attributes available to scripts. You must open a user object before you can access the attributes of the user object. If you access the user object’s attributes before you open it, it will cause an execution error.

We define a component once, then reuse it many TIMES as we need without any ADDITIONAL WORK.

We define a component once, then reuse it many times as we need without any additional work.

Non-visual USER object is an object that encapsulates attributes and functions but is not visible to the user. NVO is a collection of business user functions. They can be Custom CLASS and Standard Class. NVOs are useful because they allow you to encapsulate application OPERATIONS into objects making them easier to develop, manage and maintain and ALSO to encapsulate all security management for an application into a single object.

Non-visual user object is an object that encapsulates attributes and functions but is not visible to the user. NVO is a collection of business user functions. They can be Custom Class and Standard Class. NVOs are useful because they allow you to encapsulate application operations into objects making them easier to develop, manage and maintain and also to encapsulate all security management for an application into a single object.

It compiles all codes of an object(s). Regeneration is important during the DEVELOPMENT of our PB application. Regeneration is useful :

when we have an error message with no reason for it;

When we upgrade to a new version of PB, the new version should REGENERATE all its source code to update it;

When we make a change to an ancestor window that has many descendants, the CHANGES can be immediately rippled throughout all child window through regeneration. Regenerating could be called “recompiling”. When you regenerate an entry, PowerBuilder RECOMPILES the source form stored in the LIBRARY and replaces the existing compiled form with the recompiled form.

It compiles all codes of an object(s). Regeneration is important during the development of our PB application. Regeneration is useful :

when we have an error message with no reason for it;

When we upgrade to a new version of PB, the new version should regenerate all its source code to update it;

When we make a change to an ancestor window that has many descendants, the changes can be immediately rippled throughout all child window through regeneration. Regenerating could be called “recompiling”. When you regenerate an entry, PowerBuilder recompiles the source form stored in the library and replaces the existing compiled form with the recompiled form.

• DROPDOWN
• CASCADING
• Pop-up

PBR file is an ASCII File in which we list resource NAMES or DW object names that were REFERENCED DYNAMICALLY in the script.

PBR file is an ASCII File in which we list resource names or DW object names that were referenced dynamically in the script.

We create .PBR if we have any dynamically ASSIGNED OBJECTS, bitmaps or icons and to reduce the number of files we need to distribute with the .EXE. We typically use a .PBR when we have scripts in our application in which we dynamically assign resources to attributes of objects or controls in the application. If we do not use a .PBR, we must distribute various .BMP, .RLE, .ICO files with the application. We must place in .PBD’s any objects that we REFERENCE dynamically in scripts in the application.

We create .PBR if we have any dynamically assigned objects, bitmaps or icons and to reduce the number of files we need to distribute with the .EXE. We typically use a .PBR when we have scripts in our application in which we dynamically assign resources to attributes of objects or controls in the application. If we do not use a .PBR, we must distribute various .BMP, .RLE, .ICO files with the application. We must place in .PBD’s any objects that we reference dynamically in scripts in the application.

We use .PBD when the number and size of the objects in our application would otherwise make a very large .EXE (1.2 to 1.5 megabytes). we need to share components AMONG several APPLICATIONS. distribute application components SELECTIVELY, for example, to upgrade an application or FIX a bug.

We use .PBD when the number and size of the objects in our application would otherwise make a very large .EXE (1.2 to 1.5 megabytes). we need to share components among several applications. distribute application components selectively, for example, to upgrade an application or fix a bug.

MDI stand for Multiple Document INTERFACE. It is an application STYLE that ALLOWS users to open multiple windows(called sheets) in a single window(called MDI Frame) and to move freely among these sheet.

MDI has two PB window STYLES:

• MDI Frame
• MDI Frame with MicroHelp

MDI Frame has three parts:

• Frame
• CLIENT Area
• Sheets

MDI stand for Multiple Document Interface. It is an application style that allows users to open multiple windows(called sheets) in a single window(called MDI Frame) and to move freely among these sheet.

MDI has two PB window styles:

MDI Frame has three parts:

When PB encounters HALT WITHOUT the keyword CLOSE, it immediately terminates the APPLICATION.

When PB encouters HALT with the keyword CLOSE, it immediately EXECUTED the SCRIPT for the close event for the application and then terminates the applicaiton.

When PB encounters HALT without the keyword CLOSE, it immediately terminates the application.

When PB encouters HALT with the keyword CLOSE, it immediately executed the script for the close event for the application and then terminates the applicaiton.

MAIN: A standlone overlaped window that can be independed of all other WINDOWS. Used for SINGLE window application.

CHILD: A window that is dependent on a main window and can only exist within the main(PARENT) window. If minimize the main window as WELL as the child window is minimizsed. A child window cannot beyond the parent window.

MDI: MDI window allows to open multiple window as sheet inside it. When a window inside the MDI window it minimize and maximized wheet icon is displayed at the bottom of the MDI window.

MDIHELP: MDIHELP window has additional feature of a status bar at the bottom of the MDIHELP window. This status bar used to DISPLAY help text like run time.

POPUP: POPUP window depends on it parent window. POPUP window will behave like a main window. IT the parent window is minimized POPUP window will be hidden.

RESPONSE: RESPONSE window equalent of a window dialog box. When a response window is opened from another window the response window can’t minimize and maximize untill the user gives response to the window can»t get another window.

MAIN: A standlone overlaped window that can be independed of all other windows. Used for single window application.

CHILD: A window that is dependent on a main window and can only exist within the main(PARENT) window. If minimize the main window as well as the child window is minimizsed. A child window cannot beyond the parent window.

MDI: MDI window allows to open multiple window as sheet inside it. When a window inside the MDI window it minimize and maximized wheet icon is displayed at the bottom of the MDI window.

MDIHELP: MDIHELP window has additional feature of a status bar at the bottom of the MDIHELP window. This status bar used to display help text like run time.

POPUP: POPUP window depends on it parent window. POPUP window will behave like a main window. IT the parent window is minimized POPUP window will be hidden.

RESPONSE: RESPONSE window equalent of a window dialog box. When a response window is opened from another window the response window can’t minimize and maximize untill the user gives response to the window can»t get another window.

Dynamic DESCRIPTION Area stores information about input and output parameters. The TWO PRINCIPLE of dynamic SQL are PREPARE and EXECUTE.

Dynamic Description Area stores information about input and output parameters. The two principle of dynamic SQL are PREPARE and EXECUTE.

DYNAMIC STAGING AREA is internally USED by PowerBuilder and is the connection between execution of a statement and Transaction OBJECT. SQLSA contains no.of parameters and SQL statements.

Dynamic Staging Area is internally used by PowerBuilder and is the connection between execution of a statement and Transaction object. SQLSA contains no.of parameters and SQL statements.

Transaction OBJECT contains the NECESSERY informaiton needed to CONNECT to a database. Like user id , PASSWORD..

SETTRANSOBJECT()

SetTransObject tells the DataWindow to use specified transaciton object.

SETTRANS()

The DataWindow control connects and disconnects after each Retrieve or UPDATE function while using SetTrans

When we use SetTrans we can’t update multiple DataWindow object.

Transaction object contains the necessery informaiton needed to connect to a database. Like user id , password..

SETTRANSOBJECT()

SetTransObject tells the DataWindow to use specified transaciton object.

SETTRANS()

The DataWindow control connects and disconnects after each Retrieve or Update function while using SetTrans

When we use SetTrans we can’t update multiple DataWindow object.

PUBLIC, PROTECTED, PRIVATE, PrivateRead, PrivateWrite, ProtectedRead, ProtectedWrite.

Public, Protected, Private, PrivateRead, PrivateWrite, ProtectedRead, ProtectedWrite.

PostEvent() will be EXECUTED after COMPLETING the CURRENT script execution. PostEvent() executes asychronously. PostEvent() SCRIPTS are bending in the message queue.

PostEvent() will be executed after completing the current script execution. PostEvent() executes asychronously. PostEvent() scripts are bending in the message queue.

TriggerEvent() executes the specifed EVENT’s script right way. All pre-defined events are defined as ENUMERATED DATA types under TriggerEvent().

TriggerEvent() FUNCTION executes synchronously, the next command after this command will not be executed untill thios command is executed completly.

Return TYPE is :

Return 1 Successfully Executed.
Return -1 Invalid.

TriggerEvent() executes the specifed event’s script right way. All pre-defined events are defined as enumerated data types under TriggerEvent().

TriggerEvent() function executes synchronously, the next command after this command will not be executed untill thios command is executed completly.

Return type is :

Return 1 Successfully Executed.
Return -1 Invalid.

DDE MEANS DYNAMIC Data Exchange. This technology allows TWO DIFFERENT applications talk to each other under MS-Windows environment and exchange data between them.

DDE means Dynamic Data Exchange. This technology allows two different applications talk to each other under MS-Windows environment and exchange data between them.

Computed fields are defined in DATAWINDOW BANDS and PowerBuilder CALCULATES these values, not the database SERVER.

Computed fields are defined in DataWindow bands and PowerBuilder calculates these values, not the database server.

Computed clumn is a COLUMN that we define as a part of the SELECT statement. This VALUES are calculated by the database and send to the PowerBuilder.

Computed clumn is a column that we define as a part of the SELECT statement. This values are calculated by the database and send to the PowerBuilder.

DBERROR() event is fired when a database RELATED ERROR occurs.

ERROR() event at the DataWindow CONTROL level is triggered, when a wrong EXPRESSION is encountered in the object notaiton.

DBERROR() event is fired when a database related error occurs.

ERROR() event at the DataWindow control level is triggered, when a wrong expression is encountered in the object notaiton.

POWERBUILDER displays the first ROW on the SCREEN when its complete retrieveing. When we scroll downward additional rows are RETRIEVED.

PowerBuilder displays the first row on the screen when its complete retrieveing. When we scroll downward additional rows are retrieved.

We use SETTRANS() when only a LIMITED No. of connections to the DB is allowed or we are only retrieving data and do not need to hold DB locks on RECORDS the user is modifying.

We use SetTrans() when only a limited No. of connections to the DB is allowed or we are only retrieving data and do not need to hold DB locks on records the user is modifying.

SetTransObject() works faster because it doesn’t perform Connect and Disconnect each time we call it. When we specify SetTrans() system Does all TRANSACTION Automatically. When we specify SetTransObject() we have to manage all Transaction by ourselves. When we use SetTrans( ) in a script, the DataWindow uses its internal transaction object and automatically connects and DISCONNECTS as needed; any errors that occur CAUSE an automatic ROLLBACK.

Use SetTrans() when we WANT PowerBuilder to manage the database connections automatically because we have a limited number of available connections or will be used the application from a remote location. SetTrans() is appropriate when we are only retrieving data and do not need to hold database locks on records the user is modifying. However, for better performance, we should use SetTransObject().

SetTransObject() works faster because it doesn’t perform Connect and Disconnect each time we call it. When we specify SetTrans() system Does all transaction Automatically. When we specify SetTransObject() we have to manage all Transaction by ourselves. When we use SetTrans( ) in a script, the DataWindow uses its internal transaction object and automatically connects and disconnects as needed; any errors that occur cause an automatic rollback.

Use SetTrans() when we want PowerBuilder to manage the database connections automatically because we have a limited number of available connections or will be used the application from a remote location. SetTrans() is appropriate when we are only retrieving data and do not need to hold database locks on records the user is modifying. However, for better performance, we should use SetTransObject().

Unbound data type that stands for binary large OBJECT. USUALLY used to hold pictures in database, window’s wave SOUND FILE or MIDI MUSIC.

Unbound data type that stands for binary large object. Usually used to hold pictures in database, window’s wave sound file or MIDI music.

In the RETRIEVE().

In the RETRIEVE().

DBCancel()

DBCancel()

We use SETTRANS() or SETTRANSOBJECT().

When we use SETTRANS(), the DW CONTROL uses its own Transaction OBJECT and automatically performs connect, disconnect, commit and rollback. The SetTransObject() TELLS the DW control to SHARE the transaction object with other DW CONTROLS. We have to control the database processing and we are responsible for managing database transactions. Application performance is better when we use SetTransObject().

We use SETTRANS() or SETTRANSOBJECT().

When we use SETTRANS(), the DW control uses its own Transaction object and automatically performs connect, disconnect, commit and rollback. The SetTransObject() tells the DW control to share the transaction object with other DW controls. We have to control the database processing and we are responsible for managing database transactions. Application performance is better when we use SetTransObject().

We use computed fields if we need some calculation BASED on COLUMN data that change for each retrieved row, some summary statistics SYSTEM INFORMATION (as current DATE and time).

We use computed fields if we need some calculation based on column data that change for each retrieved row, some summary statistics system information (as current date and time).

We should OPEN the print job by CALLING the PrintOpen() function. After that, we can print DWs by using PrintDataWindow() function. After that, we close the print job by calling PrintClose(). When we use PrintDataWindow() with PrintOpen() and PrintClose(), we can print several DataWindows in one print job. The INFO in each DataWindow CONTROL starts printing on a new page. 

Example:

long job
job = PrintOpen() //Each DataWindow starts printing on a new page.
PrintDataWindow(job, dw_EmpHeader)
PrintDataWindow(job, dw_EmpDetail)
PrintDataWindow(job, dw_EmpDptSum)
PrintClose()

We should open the print job by calling the PrintOpen() function. After that, we can print DWs by using PrintDataWindow() function. After that, we close the print job by calling PrintClose(). When we use PrintDataWindow() with PrintOpen() and PrintClose(), we can print several DataWindows in one print job. The info in each DataWindow control starts printing on a new page. 

Example:

long job
job = PrintOpen() //Each DataWindow starts printing on a new page.
PrintDataWindow(job, dw_EmpHeader)
PrintDataWindow(job, dw_EmpDetail)
PrintDataWindow(job, dw_EmpDptSum)
PrintClose()

1. ONE from the DATABASE SIDE
2. One from the CLIENT side

Write some code in the DBError EVENT

For EXAMPLE:

IF SQLCA.SQLCode <> 0 THEN
MessageBox()
return 1
END IF

Write some code in the DBError Event

For example:

IF SQLCA.SQLCode <> 0 THEN
MessageBox()
return 1
END IF

GetChild()

GetChild()

USING GETVALUE() and SETVALUE() FUNCTIONS.

Using GETVALUE() and SETVALUE() functions.

Specifies whether PowerBuilder uses the code table for the COLUMN to validate data.

VALUES are Boolean: True–Uses code table to validate data; False–Does not use code table to validate data.

The appearance of the text is specified by the edit MASK.

Each row in the Code Table is a pair of corresponding values: a display VALUE that user sees and data values-those that are saved in the DATABASE.

Code Tables are used with DropDownListBox and RadioButtons. 

Specifies whether PowerBuilder uses the code table for the column to validate data.

Values are Boolean: True–Uses code table to validate data; False–Does not use code table to validate data.

The appearance of the text is specified by the edit mask.

Each row in the Code Table is a pair of corresponding values: a display value that user sees and data values-those that are saved in the database.

Code Tables are used with DropDownListBox and RadioButtons. 

It’s DATAWINDOW object property (Expressions) which we can CHANGE DYNAMICALLY using MODIFY() function.

It’s DataWindow object property (Expressions) which we can change dynamically using Modify() function.

SelectRow()
ll_row = FIND()
if ll_row &GT; 0 then SelectRow (ll_row)

SelectRow()
ll_row = Find()
if ll_row > 0 then SelectRow (ll_row)

COMPUTED COLUMNS are created as a result of a SQL QUERY on the server side.

Computed fieldsas a result of INTERNAL processing by DataWindow on the client side.

Computed columns are created as a result of a SQL query on the server side.

Computed fieldsas a result of internal processing by DataWindow on the client side.

SetSort() and Sort().

SetSort() defines the sort criteria (primary, SECONDARY sort FILES - ASCENDING or descending order, ETC.).

Sort() performs the actual sort.

SetSort() and Sort().

SetSort() defines the sort criteria (primary, secondary sort files - ascending or descending order, etc.).

Sort() performs the actual sort.

Change the tab VALUE of the FIELD to zero in the DATAWINDOW PAINTER.

Change the tab value of the field to zero in the DataWindow painter.

dw_1.SetUpdateStatus()
dw_1.SetItemStatus()
dw_1.GetUpdateStatus()
dw_1.GetItemStatus()

dw_1.SetUpdateStatus()
dw_1.SetItemStatus()
dw_1.GetUpdateStatus()
dw_1.GetItemStatus()

The Data Source determines how we select the data that will be used in the DW object. If the data for the DataWindow object is retrieved from a database, we may choose one of the following Data Sources:

Quick Select is a select from one or multiple tables that are joined through foreign KEYS and may INCLUDE simple selection criteria which appear on the WHERE clause. We can only choose columns, selection criteria, and sorting. We cannot specify grouping before rows retrieved, include computed columns, or specify retrieval arguments.

SQL Select is an SQL Select statement from one or more tables in a relational database and may include selection criteria that appear on any of the possible Select statement clauses (can include selection criteria (WHERE clause), sorting criteria (ORDER BY clause), grouping criteria (GROUP BY and HAVING clauses), computed columns, one or more arguments to be supplied during execution.

Query is a predefined SQL Select statement, which must be previously constructed and saved as a Query object.

Stored PROCEDURE indicates that the DataWindow will execute a Stored Procedure and display the data in the first result set. This Data Source only appears if the DBMS to which PowerBuilder is connected and which supports Stored Procedures. We can specify that the data for a DataWindow object is retrieved through a stored procedure if our DBMS supports Stored Procedures.

External is used when the data is not in the database and the DataWindow object will be populated from a script or data will be imported from a DDE application. If the data is not in the DB, we select External as the Data Source. This includes the following situations:

• If the DataWindow object is populated from a script
• If data is imported from a DDE application
• If data is imported from an external file, such as a tab-separated text file (.TXT file) or a dBASE file (.DBF file).

Externalindicates that we have CODED a script that supplies the DataWindow object with its data. We use this Data Source when the data is in a .TXT or .DBF file or obtained through DDE. We may also use it when we plan to obtain the data by embedding our own SQL Select statement in a script. With this Data Source the DataWindow object does not issue its own SQL statement. We specify the data columns and their types so that PB can build an appropriate

DataWindow object to hold the data. These columns make up the result set. In a script, we will need to tell PowerBuilder how to get data into the DataWindow in our application. Typically, we will import data during execution using a PowerScript Import function (such as ImportFile() and ImportString() or do some data manipulation and use the SetItem() function to populate the DataWindow.

The Data Source determines how we select the data that will be used in the DW object. If the data for the DataWindow object is retrieved from a database, we may choose one of the following Data Sources:

Quick Select is a select from one or multiple tables that are joined through foreign keys and may include simple selection criteria which appear on the WHERE clause. We can only choose columns, selection criteria, and sorting. We cannot specify grouping before rows retrieved, include computed columns, or specify retrieval arguments.

SQL Select is an SQL Select statement from one or more tables in a relational database and may include selection criteria that appear on any of the possible Select statement clauses (can include selection criteria (WHERE clause), sorting criteria (ORDER BY clause), grouping criteria (GROUP BY and HAVING clauses), computed columns, one or more arguments to be supplied during execution.

Query is a predefined SQL Select statement, which must be previously constructed and saved as a Query object.

Stored Procedure indicates that the DataWindow will execute a Stored Procedure and display the data in the first result set. This Data Source only appears if the DBMS to which PowerBuilder is connected and which supports Stored Procedures. We can specify that the data for a DataWindow object is retrieved through a stored procedure if our DBMS supports Stored Procedures.

External is used when the data is not in the database and the DataWindow object will be populated from a script or data will be imported from a DDE application. If the data is not in the DB, we select External as the Data Source. This includes the following situations:

Externalindicates that we have coded a script that supplies the DataWindow object with its data. We use this Data Source when the data is in a .TXT or .DBF file or obtained through DDE. We may also use it when we plan to obtain the data by embedding our own SQL Select statement in a script. With this Data Source the DataWindow object does not issue its own SQL statement. We specify the data columns and their types so that PB can build an appropriate

DataWindow object to hold the data. These columns make up the result set. In a script, we will need to tell PowerBuilder how to get data into the DataWindow in our application. Typically, we will import data during execution using a PowerScript Import function (such as ImportFile() and ImportString() or do some data manipulation and use the SetItem() function to populate the DataWindow.

NEWMODIFIED! When a ROW is INSERTED into a DATAWINDOW it is initially has a row STATUS of NEW!, and all columns in a row initially have a column status of NOTMODIFIED!.

NEWMODIFIED! When a row is inserted into a DataWindow it is initially has a row status of NEW!, and all columns in a row initially have a column status of NOTMODIFIED!.

In a NESTED report each report has its own DATA SOURCE. Composite report does not have its own data source-it is just a container for other REPORTS.

In a Nested report each report has its own data source. Composite report does not have its own data source-it is just a container for other reports.

We USE them when we NEED to UPDATE multiple DATABASE tables from one DataWindow.

We use them when we need to update multiple DataBase tables from one DataWindow.

We can change the select STATEMENT by using functions SetSQLSelect() or by changing the DATA attributes Table.Select by calling function Modify().

Modify() is PREFERABLE because it WORKS FASTER.

dw_1.Modify(“datawindow.Table.Select = ‘Select * from customer’”)

We can change the select statement by using functions SetSQLSelect() or by changing the data attributes Table.Select by calling function Modify().

Modify() is preferable because it works faster.

dw_1.Modify(“datawindow.Table.Select = ‘Select * from customer’”)

SQLDBCode

SQLDBCode