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

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
sb: HCkStringBuilder;
bd: HCkBinData;
sbFilename: HCkStringBuilder;
index: Integer;
success: Boolean;
mayHaveMore: Boolean;
sBase64: PWideChar;
count: Integer;

begin
sb := CkStringBuilder_Create();
bd := CkBinData_Create();
sbFilename := CkStringBuilder_Create();
index := 1;

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

mayHaveMore := True;
while mayHaveMore = True do
  begin

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

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

    if (CkStringBuilder_getLastMethodSuccess(sb) = True) then
      begin
        // Found something.
        // Load into bd and save.
        success := CkBinData_LoadEncoded(bd,sBase64,'base64');

        CkStringBuilder_SetString(sbFilename,'qa_output/png_');
        CkStringBuilder_AppendInt(sbFilename,index);
        CkStringBuilder_Append(sbFilename,'.png');

        CkBinData_WriteFile(bd,CkStringBuilder__getAsString(sbFilename));

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

    index := index + 1;
  end;

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

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

CkStringBuilder_Dispose(sb);
CkBinData_Dispose(bd);
CkStringBuilder_Dispose(sbFilename);

end;