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New Blog Posts: Merging Reports - Part 1 and Part 2

Storing Custom Report Description

edited November 2001 in General
Hi,

Is there any property that allows custom text, like a report description to
be stored directly inside the RTM file? Our app does not use the report
explorer, and we'd like to store the description with the report file
itself. Is this possible?

Thanks,
Vinnie Murdico

Comments

  • edited November 2001
    -----------------------------------------------------
    Tech Tip: Storing Custom Information with Templates
    -----------------------------------------------------

    Question:
    ---------

    How can I store descriptive information with my report template?


    Solution:
    ---------

    1. If you are storing the templates to a database, then you can use the
    Report.Template.OnSaveEnd and OnLoadEnd events to store and load the
    custom information to appropriate data fields for the record. (This is
    the technique used by the ReportExplorer.)

    2. If you are storing templates to .rtm files, then you will need to
    store the custom information in an Offset area of the template file. The
    Report.Template object enables you do this by utilizing the
    Template.Offset property and the Template.OnLoadStart and OnLoadEnd
    events. Below is a detailed example.



    Example:
    --------
    - Create a new application.
    - Add to the main form one TButton, one TppReport and one TppDesigner.
    - Set the Designer's Report property to ppReport1.
    - Add ppTypes to the uses clause.


    type
    TForm1 = class(TForm)
    Button1: TButton;
    ppReport1: TppReport;
    ppDesigner1: TppDesigner;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    private
    procedure LoadReportStreamEvent(Sender: TObject; Stream: TStream);
    procedure SaveReportStreamEvent(Sender: TObject; Stream: TStream);

    public

    end; { class TForm1 }


    {note: use compiler directive to declare strings as 'ShortStrings'
    this is required for record structures}

    {$H-}

    {record structure used to store information inside report template }
    TmyTemplateInfo = record
    HeaderID: Integer;
    Comments: String;
    DateTime: TDateTime;

    end; {record, TppTemplateRec}

    {$H+}


    const
    cHeaderID = 12345;

    implementation


    {-------------------------------------------------}
    { TForm1.FormCreate }

    procedure TForm1.FormCreate(Sender: TObject);
    begin

    {setup Template events }
    ppReport1.Template.Format := ftASCII;
    ppReport1.Template.Offset := SizeOf(TmyTemplateInfo);
    ppReport1.Template.OnLoadStart := LoadReportStreamEvent;
    ppReport1.Template.OnSaveEnd := SaveReportStreamEvent;

    end; {procedure, FormCreate}

    {-------------------------------------------------}
    { TForm1.Button1Click }

    procedure TForm1.Button1Click(Sender: TObject);
    begin

    ppDesigner1.Show;

    end; {procedure, Button1Click}

    {--------------------------------------------------}
    { TForm1.LoadReportStreamEvent }

    procedure TForm1.LoadReportStreamEvent(Sender: TObject; Stream:
    TStream);
    var
    lTemplateInfo: TmyTemplateInfo;
    lsMessage: String;

    begin

    {read string stored in template header }
    Stream.Seek(0, soFromBeginning);
    Stream.Read(lTemplateInfo, SizeOf(TmyTemplateInfo));

    {note: if not one of the templates with our header info, then set
    Offset to 0 }
    if lTemplateInfo.HeaderID = cHeaderID then
    begin
    lsMessage := 'Reading data from template file: ' + #13#10 + #13#10
    +
    lTemplateInfo.Comments + ' (' +
    DateTimeToStr(lTemplateInfo.DateTime) + ')';

    MessageDlg(lsMessage, mtInformation, [mbOK],0);
    ppReport1.Template.Offset := SizeOf(TmyTemplateInfo);
    end
    else
    ppReport1.Template.Offset := 0;

    end; {procedure, LoadReportStreamEvent}


    {------------------------------------------------------------------------------}
    { TForm1.SaveReportStreamEvent }

    procedure TForm1.SaveReportStreamEvent(Sender: TObject; Stream:
    TStream);
    var
    lTemplateInfo: TmyTemplateInfo;
    lsMessage: String;

    begin

    lTemplateInfo.HeaderID := cHeaderID;
    lTemplateInfo.Comments := 'This comment is being stored inside the
    report template, ' + #13#10 +
    'along with the date and time written. ';
    lTemplateInfo.DateTime := Now;

    {write info to template header}
    Stream.Seek(0, soFromBeginning);
    Stream.Write(lTemplateInfo, SizeOf(TmyTemplateInfo));

    lsMessage := 'Writing data to template file: ' + #13#10 + #13#10 +
    lTemplateInfo.Comments + ' (' +
    DateTimeToStr(lTemplateInfo.DateTime) + ')';
    MessageDlg(lsMessage, mtInformation, [mbOK],0);

    end; {procedure, SaveReportStreamEvent}








    Best regards,

    Nard Moseley
    Digital Metaphors
    www.digital-metaphors.com
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