Celestin Apprentice 4/Apprentice-Release4.iso/Demos/AppMaker 2.0b3/Demo AppMaker 1.5/Demo AppMaker™/Demo AppMaker™.rsrc/TmPT_111_Data

Text File | 1992-04-08 | 4.3 KB | 201 lines

{ %filename% -- data access methods}
{ Created %date% %time% by AppMaker}

{    This module contains data structures to access the data in your}
{    document's file(s). The intent is to isolate the details of the}
{    data representation into this module and to provide accessor}
{    functions for reading/writing logical pieces of the data.}
{    For your application, you will probably rewrite most of this.}
{    This module will not be regenerated by AppMaker unless you delete it.}

Unit %unitname%;
Interface

Uses
    TCL,
    AMCL,
    ResourceDefs;

{Define the creator type and file type for your application:}
const
    kSignature        = 'XXXX';
    kFileType        = 'TEXT';

type
    C%appname%Data    = object (CDataFile)
        hasFile:        boolean;
        itsDocument:    CDocument;

    {define your own internal data structures:}
        itsData:        Handle;


        Procedure I%appname%Data    (theDocument:    CDocument);
        Procedure Free;        override;

        Procedure Close;    override;
        Procedure OpenData    (permission:    SignedByte);
        Function  Save: Boolean;
        Function  SaveAs    (macSFReply:    SFReply): Boolean;
        Procedure Revert;

        Procedure ReadData;
        Function  WriteData: Boolean;
        Procedure DisposeData;

    {accessor functions, replace these with application-specific functions:}
        Procedure Get%appname%;
        Procedure Put%appname%;
        Procedure Add%appname%;
        Procedure Delete%appname%;

    end; {C%Appname%Data}

{----------}
Implementation

{----------}
Procedure C%appname%Data.I%appname%Data    (theDocument:    CDocument);
Begin
    inherited IDataFile;
    hasFile := false;
    itsDocument := theDocument;

    {your application-specific initialization}
    itsData := nil;

End; {I%appname%Data}

{----------}
Procedure C%appname%Data.Free;
Begin
    DisposeData;
    inherited Free;
End; {Free}

{----------}
Procedure C%appname%Data.OpenData    (permission:    SignedByte);
Begin
    Open (permission);
    hasFile := true;

    ReadData;

End; {OpenData}

{----------}
Procedure C%appname%Data.Close;
Begin
    inherited Close;
    hasFile := false;
    {don't DisposeData because data may be needed by SaveAs}
End; {Close}

{----------}
Function C%appname%Data.Save: Boolean;
Begin
    if hasFile then begin
        Save := WriteData;
    end else begin
        {shouldn't be called in this case}
        Save := false;
    end;
End; {Save}

{----------}
Function C%appname%Data.SaveAs    (macSFReply:    SFReply): Boolean;
var
    ignoreErr:        OSErr;
Begin
{ If all of your data is in memory, then just close the current file}
{ create and open a file, then save your data into the new file}

{ If some of your data is in the current file and not in memory,}
{ you may have to create and open the new file,}
{ copy data from the current file to the new file,}
{ close the current file,}
{ then save your data into the new file}

    if hasFile then begin
        Close;
    end;
    SFSpecify (macSFReply);
    ignoreErr := HDelete (volNum, dirID, name);    {in case already exists}
    CreateNew (gSignature, kFileType);
    Open (fsRdWrPerm);
    hasFile := true;

    SaveAs := Save;
End; {SaveAs}

{----------}
Procedure C%appname%Data.Revert;
Begin
    DisposeData;
    if hasFile then begin
        ReadData;
    end;
End; {Revert}


{ The next few methods are for transferring data between the }
{ data file and your internal data structures, and for disposing}
{ your data structures. They are called by Open, Close, etc.}
{ Replace their bodies with whatever is suitable for your application}

{ define internal data structures to describe the file format:}
type
    fileData        = record
        stuff:            integer;
    end;

{----------}
Procedure C%appname%Data.ReadData;
Begin
    itsData := ReadAll;
End; {ReadData}

{----------}
Function C%appname%Data.WriteData: Boolean;
Begin
    WriteAll (itsData);
    WriteData := true;
End; {WriteData}

{----------}
Procedure C%appname%Data.DisposeData;
Begin
    if itsData <> nil then begin
        DisposHandle (itsData);
        itsData := nil;
    end;
End; {DisposeData}


{ The remaining methods are for accessing your data as logical chunks.}
{ These are just models for your own accessor functions;}
{ they aren't called by any AppMaker-generated code.}
{ Replace them with whatever is suitable for your application.}

{----------}
Procedure C%appname%Data.Get%appname%;
Begin
End; {Get%appname%}

{----------}
Procedure C%appname%Data.Put%appname%;
Begin
End; {Put%appname%}

{----------}
Procedure C%appname%Data.Add%appname%;
Begin
End; {Add%appname%}

{----------}
Procedure C%appname%Data.Delete%appname%;
Begin
End; {Delete%appname%}

End. {%unitname%}