Pascal (Lazarus/Delphi)

S3 Get Bucket Objects with CommonPrefixes

See more Amazon S3 Examples

Demonstrates how to get a list of bucket objects using the prefix and delimiter query params to get an XML result with CommonPrefixes. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Xml,
  Chilkat.Http;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  http: THttp;
  strXml: string;
  xml: TXml;
  Prefix: string;
  i: Integer;
  count_i: Integer;

begin
  success := False;

  //  This example assumes the Chilkat HTTP API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  http := THttp.Create;

  //  Insert your access key here:
  http.AwsAccessKey := 'AWS_ACCESS_KEY';

  //  Insert your secret key here:
  http.AwsSecretKey := 'AWS_SECRET_KEY';

  //  In this example, my bucket is "chilkat100".
  //  It contains a number of folders, one of which is named "images".
  //  I want to get a list of all sub-folders under the "images" folder
  strXml := http.S3_ListBucketObjects('chilkat100?prefix=images/&delimiter=/');
  if (http.LastMethodSuccess <> True) then
    begin
      WriteLn(http.LastErrorText);
      Exit;
    end;

  WriteLn('Response status code = ' + http.LastStatus);

  xml := TXml.Create;
  success := xml.LoadXml(strXml);
  if (success <> True) then
    begin
      WriteLn(xml.LastErrorText);
      Exit;
    end;

  //  If the response status code was not 200, then the XML response is not a 
  //  listing of objects, but instead contains error information.
  if (http.LastStatus <> 200) then
    begin
      WriteLn(xml.GetXml());
      WriteLn('Failed.');
      Exit;
    end;

  //  A sample response is shown below.
  WriteLn(xml.GetXml());
  WriteLn('----');

  //  Here is the list of sub-folders (i.e. CommonPrefixes)

  //  <?xml version="1.0" encoding="UTF-8"?>
  //  <ListBucketResult xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
  //      <Name>chilkat100</Name>
  //      <Prefix>images/</Prefix>
  //      <Marker/>
  //      <MaxKeys>1000</MaxKeys>
  //      <Delimiter>/</Delimiter>
  //      <IsTruncated>false</IsTruncated>
  //      <CommonPrefixes>
  //          <Prefix>images/africa/</Prefix>
  //      </CommonPrefixes>
  //      <CommonPrefixes>
  //          <Prefix>images/sea_creatures/</Prefix>
  //      </CommonPrefixes>
  //  </ListBucketResult>

  //  The XML can be parsed like this:
  i := 0;
  count_i := xml.NumChildrenHavingTag('CommonPrefixes');
  while i < count_i do
    begin
      xml.I := i;
      Prefix := xml.GetChildContent('CommonPrefixes[i]|Prefix');
      WriteLn('Prefix = ' + Prefix);
      i := i + 1;
    end;



  http.Free;
  xml.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.