cdataenv.prg

MSComm控件资料,Visual Basic 6.0(以下简称VB) 是一种功能强大、简单易学的程序设计语言。它不但保留了原先Basic语言的全部功能

		*   Returns:  LOGICAL
		*     .T. if the database is valid
		*     .F. if it is not
		*------------------ Maintenance Section --------------------
		*@  Inputs:
		*@    1.  cDataEnvironment.cDefaultDatabase
		*@    2.  cDataEnvironment.cDefaultDatabaseName
		*   Outputs:
		*   Pre-condition Invariants:
		*     1.  The method GetDefaultDatabase() must have executed
		*         and derived the fully qualified drive, path and
		*         name of the default database and placed this information
		*         into the cDefaultDatabase property.
		*   Post-condition Invariants:
		*     1.  The fully qualified name of the default database was
		*         provided AND the file exists in the specified location.
		*?  Notes: None
		*   Collaborating Methods:
		*     1.  ErrorMsg() in UTILS.PRG
		*-- Process:
		*--   1.  IF the default database (fully qualified drive, path and
		*--       name) has not been provided OR the specified file
		*--       does not exist
		*--   2.     Message the user that the default database cannot be found
		*--   3.     Condition the return value to return a failed condition
		*--       ENDIF
		*   Change Log:
		*      MODIFIED
		*--------- (c) Flash Creative Management, Inc. -------------
		*---------------- Commenting Provided By -------------------
		*   Software Assets of Virginia, Inc. (SAVI)
		*   Charles T. Blankenship, President
		*   Compuserve: 76132,2575
		*     Internet: www.savvysolutions.com
		*      eMail 1: [e-mail]
		*      eMail 2: [e-mail]
		*        Voice: [phone]
		************************************************************
		LOCAL llRetVal
		llRetVal = .T.

		IF EMPTY(This.cDefaultDatabase) OR !FILE(This.cDefaultDatabase)
			=ErrorMsg(CANNOTFINDDATABASE_LOC + " " + This.cDefaultDatabase)
			llRetVal = .F.
		ENDIF

		RETURN llRetVal

	ENDFUNC

	FUNCTION SetInitiallySelectedAlias()
		*-------------------- Location Section ---------------------
		*   Library: cDataEnv.PRG
		*   Class:   cDataEnvironment
		*   Method:  SetInitiallySelectedAlias
		*--------------------- Usage Section -----------------------
		*)  Description:
		*)     Places the name of the cursor that was designated to
		*)     be the intially selected alias (by the developer) into the
		*)     .InitialSelectedAlias property.
		*   Scope: PUBLIC
		*   Parameters: None
		*$  Usage:
		*$    cDataEnvironment::SetInitiallySelectedAlias()
		*%  Example:
		*%    This.SetInitiallySelectedAlias()
		*   Returns:  LOGICAL .T. by default
		*------------------ Maintenance Section --------------------
		*@  Inputs:
		*@    1.  cDataEnvironment.nInitialSelectedAlias
		*@    2.  cDataEnvironment.aCursors[]
		*   Outputs:
		*     1.  cDataEnvironment.InitialSelectedAlias
		*   Pre-condition Invariants:
		*     1.  The developer must have specified which
		*         cursor is desired to be the initially selected
		*         alias by appropriately populating the
		*         nInitialSelectedAlias property
		*     2.  The aCursor array must have a valid cursor
		*         name in the element that corresponds to
		*         the value in the nInitialSelectedalias property
		*   Post-condition Invariants:
		*     1.  The name of the cursor desired to be the initially
		*         selected alias is present in the InitialSelectedAlias
		*         property.
		*?  Notes: None
		*   Collaborating Methods: None
		*-- Process:
		*--   1.  If a  valid cursor name exists in the specified
		*--       element of the aCursors array for the initially selected
		*--       alias
		*--   2.     Populate the InitialSelectedAlias property with the
		*--          name of the cursor that is desired to be initially
		*--          selected when this data environment instantiates.
		*--       ENDIF
		*   Change Log:
		*      MODIFIED
		*--------- (c) Flash Creative Management, Inc. -------------
		*---------------- Commenting Provided By -------------------
		*   Software Assets of Virginia, Inc. (SAVI)
		*   Charles T. Blankenship, President
		*   Compuserve: 76132,2575
		*     Internet: www.savvysolutions.com
		*      eMail 1: [e-mail]
		*      eMail 2: [e-mail]
		*        Voice: [phone]
		************************************************************
		IF TYPE("This.aCursors[This.nInitialSelectedAlias]") == "C"
			This.InitialSelectedAlias = This.aCursors[This.nInitialSelectedAlias]
		ENDIF

	ENDFUNC


	FUNCTION CreateCursors()
		*-------------------- Location Section ---------------------
		*   Library: cDataEnv.PRG
		*   Class:   cDataEnvironment
		*   Method:  CreateCursors()
		*--------------------- Usage Section -----------------------
		*)  Description:
		*)    Loops through the aCursors array, element by element
		*)    and adds the specified cursor objects to the data
		*)    environment.
		*   Scope: Public
		*   Parameters: None
		*$  Usage:
		*$    cDataEnvironmant::CreateCursors()
		*%  Example:
		*%    This.CreateCursors()
		*   Returns:  LOGICAL .T. by default
		*------------------ Maintenance Section --------------------
		*@  Inputs:
		*@    1.  cDataEnvironment.aCursors[] - name of the class
		*@        definition from which to create the cursor.
		*@        Usually defined in ADATAENV.PRG and populated into
		*@        the array from the LoadCursors() method.
		*   Outputs:
		*     1.  Child cursor objects are added to the cDataEnvironment
		*   Pre-condition Invariants:
		*     1.  The developer must have populated the class definition
		*         in ADATAENV.PRG with the names of the cursors that
		*         are to participate in the data environment.
		*   Post-condition Invariants:
		*     1.  All of the specified cursors exist as child objects
		*         of the data environment.  The names of these objects
		*         are the names of the class definitions of the cursors
		*         with a "o" pre-pended, e.g. "ov_UserView" if the
		*         class definition was "v_UserView".
		*?  Notes: None
		*   Collaborating Methods:
		*     1.  DataEnvironment.AddObject()
		*-- Process:
		*--   1.  IF a name of the cursor's class definition is
		*--       present in the first element of the aCursor array
		*--   2.     FOR every cursor whose class definition was defined
		*--   3.        Add the cursor object to the data environment
		*--             objects as a child of the DE.  The name of the
		*--             object is derived by prepending a "o" to the
		*--             name of the cursor's class definition.
		*--          ENDFOR
		*--       ENDIF
		*   Change Log:
		*      MODIFIED
		*--------- (c) Flash Creative Management, Inc. -------------
		*---------------- Commenting Provided By -------------------
		*   Software Assets of Virginia, Inc. (SAVI)
		*   Charles T. Blankenship, President
		*   Compuserve: 76132,2575
		*     Internet: www.savvysolutions.com
		*      eMail 1: [e-mail]
		*      eMail 2: [e-mail]
		*        Voice: [phone]
		************************************************************
		LOCAL lnCursor
		IF TYPE("This.aCursors[1]") == "C"
			FOR lnCursor = 1 TO ALEN(This.aCursors, 1)
				This.AddObject("o" + This.aCursors[lnCursor], This.aCursors[lnCursor])
			ENDFOR
		ENDIF

	ENDFUNC



	FUNCTION Unload()
		*-------------------- Location Section ---------------------
		*   Library: cDataEnv.PRG
		*   Class:   cDataEnvironment
		*   Method:  Unload()
		*--------------------- Usage Section -----------------------
		*)  Description:
		*   Scope:
		*   Parameters:
		*$  Usage:
		*%  Example:
		*   Returns:  LOGICAL .T. by default
		*------------------ Maintenance Section --------------------
		*@  Inputs:
		*   Outputs:
		*   Pre-condition Invariants:
		*   Post-condition Invariants:
		*?  Notes:
		*   Collaborating Methods:
		*-- Process:
		*   Change Log:
		*--------- (c) Flash Creative Management, Inc. -------------
		*---------------- Commenting Provided By -------------------
		*   Software Assets of Virginia, Inc. (SAVI)
		*   Charles T. Blankenship, President
		*   Compuserve: 76132,2575
		*     Internet: www.savvysolutions.com
		*      eMail 1: [e-mail]
		*      eMail 2: [e-mail]
		*        Voice: [phone]
		************************************************************

		This.CloseTables()
		This.UnloadCursors()
		This.UnloadRelations()

	ENDFUNC

	FUNCTION UnloadCursors()
		*-------------------- Location Section ---------------------
		*   Library: cDataEnv.PRG
		*   Class:   cDataEnvironment
		*   Method:  UnloadCursors()
		*--------------------- Usage Section -----------------------
		*)  Description:
		*   Scope:
		*   Parameters:
		*$  Usage:
		*%  Example:
		*   Returns:  LOGICAL .T. by default
		*------------------ Maintenance Section --------------------
		*@  Inputs:
		*   Outputs:
		*   Pre-condition Invariants:
		*   Post-condition Invariants:
		*?  Notes:
		*   Collaborating Methods:
		*-- Process:
		*   Change Log:
		*--------- (c) Flash Creative Management, Inc. -------------
		*---------------- Commenting Provided By -------------------
		*   Software Assets of Virginia, Inc. (SAVI)
		*   Charles T. Blankenship, President
		*   Compuserve: 76132,2575
		*     Internet: www.savvysolutions.com
		*      eMail 1: [e-mail]
		*      eMail 2: [e-mail]
		*        Voice: [phone]
		************************************************************
		LOCAL lnCursor
		IF TYPE("This.aCursors[1]") == "C"
			FOR lnCursor = 1 TO ALEN(This.aCursors, 1)
				This.RemoveObject("o" + This.aCursors[lnCursor])
			ENDFOR
		ENDIF

	ENDFUNC

	FUNCTION UnloadRelations()
		*-------------------- Location Section ---------------------
		*   Library: cDataEnv.PRG
		*   Class:   cDataEnvironment
		*   Method:  UnloadRelations()
		*--------------------- Usage Section -----------------------
		*)  Description:
		*   Scope:
		*   Parameters:
		*$  Usage:
		*%  Example:
		*   Returns:  LOGICAL .T. by default
		*------------------ Maintenance Section --------------------
		*@  Inputs:
		*   Outputs:
		*   Pre-condition Invariants:
		*   Post-condition Invariants:
		*?  Notes:
		*   Collaborating Methods:
		*-- Process:
		*   Change Log:
		*--------- (c) Flash Creative Management, Inc. -------------
		*---------------- Commenting Provided By -------------------
		*   Software Assets of Virginia, Inc. (SAVI)
		*   Charles T. Blankenship, President
		*   Compuserve: 76132,2575
		*     Internet: www.savvysolutions.com
		*      eMail 1: [e-mail]
		*      eMail 2: [e-mail]
		*        Voice: [phone]
		************************************************************
		LOCAL lnRelation
		IF TYPE("This.aRelations[1]") == "C"
			FOR lnRelation = 1 TO ALEN(This.aRelations, 1)
				This.RemoveObject("o" + This.aRelations[lnRelation])
			ENDFOR
		ENDIF

	ENDFUNC

	FUNCTION CreateRelations()
		*-------------------- Location Section ---------------------
		*   Library: cDataEnv.PRG
		*   Class:   cDataEnvironment
		*   Method:  CreateRelations()
		*--------------------- Usage Section -----------------------
		*)  Description:
		*)    Loops through the aRelations array, element by element
		*)    and adds the specified relation objects to the data
		*)    environment.
		*   Scope: Public
		*   Parameters: None
		*$  Usage:
		*$    cDataEnvironmant::CreateRelations()
		*%  Example:
		*%    This.CreateRelations()
		*   Returns:  LOGICAL .T. by default
		*------------------ Maintenance Section --------------------
		*@  Inputs:
		*@    1.  cDataEnvironment.aRelations[] - each element contains
		*@        the name of the class definition from which to create
		*@        the relation object.  Usually defined in ADATAENV.PRG
		*@        and populated into the array from the LoadRelations()
		*@        method.
		*   Outputs:
		*     1.  Child relation objects are added to the DataEnvironment
		*   Pre-condition Invariants:
		*     1.  The developer must have populated the class definition
		*         in ADATAENV.PRG with the names of the relations that
		*         are to participate in the data environment.
		*   Post-condition Invariants:
		*     1.  All of the specified relations exist as child objects
		*         of the data environment.  The names of these objects
		*         are the names of the class definitions of the relations
		*         with a "o" pre-pended, e.g. "oRelationClassDefinition"
		*         if the class definition's name was "RelationClassDefinition".
		*?  Notes: None
		*   Collaborating Methods:
		*     1.  DataEnvironment.AddObject()
		*-- Process:
		*--   1.  IF a name of the relation's class definition is
		*--       present in the first element of the aRelation array
		*--   2.     FOR every relation whose class definition was defined
		*--   3.        Add the relation object to the data environment
		*--             object as a child of the DE.  The name of the
		*--             object is derived by prepending a "o" to the
		*--             name of the relation's class definition.
		*--          ENDFOR
		*--       ENDIF
		*   Change Log:
		*      MODIFIED
		*--------- (c) Flash Creative Management, Inc. -------------
		*---------------- Commenting Provided By -------------------
		*   Software Assets of Virginia, Inc. (SAVI)
		*   Charles T. Blankenship, President
		*   Compuserve: 76132,2575
		*     Internet: www.savvysolutions.com
		*      eMail 1: [e-mail]
		*      eMail 2: [e-mail]
		*        Voice: [phone]