Oracle Forms: create debug triggers

Oracle Forms: create debug triggers

• 1.
  Creating & DebuggingTriggers
• 2.
  Objectives • How toCreate Triggers? • Writing trigger code • Describe Built-in sub-programs used in Forms • When-Button-Pressed Trigger • When-Window-Closed Trigger • Debugging Triggers
• 3.
  How to Createa Trigger?
• 4.
  Trigger PL/SQL Block •DECLARE ------- Declarative statements (OPTIONAL) • BEGIN ------- Executable statements (MANDATORY) • EXCEPTION --------- Exception Handling. (OPTIONAL) • END;
• 5.
  Variables in FormBuilder • PL/SQL variables must be declared in triggers or must be defined in a package • Form Builder variables not required to be declared – Requires a Colon Prefix
• 6.
  Form Builder Variables •Items For presentation and user interaction :block_name.item_name • Global variables Session-wide character variable :GLOBAL.var_name • System variables Form status and control :SYSTEM.var_name • Parameters Passing values in and out of module :PARAMENTER.parameter
• 7.
  Form Builder Built-inSubprograms Built-ins belong to either: • The Standard Extensions package where no prefix is required • Another Form Builder package where a prefix is required Built-in Restricted Built-ins Unrestricted Built-ins Allowed only In certain Triggers Allowed In Any Trigger or subprogram
• 8.
  Built-in Subprograms • EDIT_TEXTITEM •ENTER_QUERY • EXECUTE_QUERY • EXIT_FORM • GO_BLOCK • GO_ ITEM • NEXT_RECORD • PREVIOUS_RECORD • MESSAGE • SHOW_ALERT • SHOW_ EDITOR • SHOW_ LOV • SHOW_VIEW • HIDE_VIEW • GET_ITEM_PROPERTY • SET_ITEM_PROPERTY
• 9.
  When-Button-Pressed Trigger • Fireswhen the operator clicks a button. • Accepts restricted and unrestricted built-ins. • Used for existing form, Display LOVs, Editors etc. Example GO_BLOCK(‘EMP’); EXECUTE_QUERY;
• 10.
  When-Window-Closed Trigger • Fireswhen the operator closes a window by clicking button. • Accepts restricted and unrestricted built-ins. • Used to programmatically close a window when the operator issues a window manager-specific close command. You can close a window by using built-ins. When-Window-Closed Trigger at Form Level. EXIT_FORM;
• 11.
  Debugging Triggers • Monitorand Debug Triggers by: – Compiling and rectifying errors in the PL/SQL Editor – Displaying debug messages at run time – Invoking the PL/SQL Debugger
• 12.
  Debugging Triggers -Tips •Connect to Database before compiling SQL statements. • Define triggers always at the correct level • Terminate statements with semicolon where ever necessary. • Watch for missing quotation marks • Place the triggers where the event will happen.
• 13.
  Running a FormIn Debug Mode Forms Debugger Window Run Form Debug
• 14.
  Debug Triggers andBreakpoint Every statement Debugger Program Unit Statement Statement Statement Debug trigger Breakpoint trigger Fire Fire Fire Breakpoint
• 15.
  PL/SQL Debugger Step Into StepOver Step Out Go Reset Debug Commands
• 16.
  Summary • Creating Trigger •From Built-ins • Restricted and Unrestricted built-ins • When-Button-Pressed trigger • When-Window-Closed Trigger