Delphi DLL

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. Delphi 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
success: Boolean;
http: HCkHttp;
strXml: PWideChar;
xml: HCkXml;
Prefix: PWideChar;
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 := 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;