(Delphi DLL) S3 Get Bucket Objects with CommonPrefixes

Demonstrates how to get a list of bucket objects using the prefix and delimiter query params to get an XML result with CommonPrefixes.

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, Xml, Http;

...

procedure TForm1.Button1Click(Sender: TObject);
var
http: HCkHttp;
strXml: PWideChar;
xml: HCkXml;
success: Boolean;
Prefix: PWideChar;
i: Integer;
count_i: Integer;

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

http := CkHttp_Create();

// Insert your access key here:
CkHttp_putAwsAccessKey(http,'AWS_ACCESS_KEY');

// Insert your secret key here:
CkHttp_putAwsSecretKey(http,'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 := CkHttp__s3_ListBucketObjects(http,'chilkat100?prefix=images/&delimiter=/');
if (CkHttp_getLastMethodSuccess(http) <> True) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

Memo1.Lines.Add('Response status code = ' + IntToStr(CkHttp_getLastStatus(http)));

xml := CkXml_Create();
success := CkXml_LoadXml(xml,strXml);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkXml__lastErrorText(xml));
    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 (CkHttp_getLastStatus(http) <> 200) then
  begin
    Memo1.Lines.Add(CkXml__getXml(xml));
    Memo1.Lines.Add('Failed.');
    Exit;
  end;

// A sample response is shown below.
Memo1.Lines.Add(CkXml__getXml(xml));
Memo1.Lines.Add('----');

// 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 := CkXml_NumChildrenHavingTag(xml,'CommonPrefixes');
while i < count_i do
  begin
    CkXml_putI(xml,i);
    Prefix := CkXml__getChildContent(xml,'CommonPrefixes[i]|Prefix');
    Memo1.Lines.Add('Prefix = ' + Prefix);
    i := i + 1;
  end;

CkHttp_Dispose(http);
CkXml_Dispose(xml);

end;