(Delphi ActiveX) Extract data:image/png;base64 from HTML

Demonstrates how to extract base64 image data from HTMl and save to files.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
sb: TChilkatStringBuilder;
bd: TChilkatBinData;
sbFilename: TChilkatStringBuilder;
index: Integer;
success: Integer;
mayHaveMore: Integer;
sBase64: WideString;
count: Integer;

begin
sb := TChilkatStringBuilder.Create(Self);
bd := TChilkatBinData.Create(Self);
sbFilename := TChilkatStringBuilder.Create(Self);
index := 1;

success := sb.LoadFile('qa_data/html/oresp body.txt','utf-8');
// Assume success.
Memo1.Lines.Add('length = ' + IntToStr(sb.Length));

mayHaveMore := 1;
while mayHaveMore = 1 do
  begin

    // Get the base64 between the 1st occurrence "data:image/png;base64," and "'"
    sBase64 := sb.GetBetween('data:image/png;base64,','''');

    // If nothing is found, then we'll exit the loop because there are no more.
    mayHaveMore := sb.LastMethodSuccess;

    if (sb.LastMethodSuccess = 1) then
      begin
        // Found something.
        // Load into bd and save.
        success := bd.LoadEncoded(sBase64,'base64');

        sbFilename.SetString('qa_output/png_');
        sbFilename.AppendInt(index);
        sbFilename.Append('.png');

        bd.WriteFile(sbFilename.GetAsString());

        // Replace "data:image/png;base64" with "data:image-png;base64" so the next iteration finds the next occurrence.
        sb.ReplaceFirst('data:image/png;base64','data:image-png;base64');
      end;

    index := index + 1;
  end;

// Restore our replacements..
count := sb.Replace('data:image-png;base64','data:image/png;base64');

Memo1.Lines.Add('All done.');
end;