(Delphi DLL) Manage Bucket Storage Class

See more Google Cloud Storage Examples

Demonstrates how to manage a bucket's default storage class.

See Cloud Storage Classes for information about storage classes.

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, Http, StringBuilder, HttpResponse, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
sbToken: HCkStringBuilder;
json: HCkJsonObject;
http: HCkHttp;
url: PWideChar;
resp: HCkHttpResponse;
responseCode: Integer;

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

// This example uses a previously obtained access token having permission for the 
// scope "https://www.googleapis.com/auth/cloud-platform"

// In this example, Get Google Cloud Storage OAuth2 Access Token, 
// the service account access token was saved to a text file.  This example fetches the access token from the file..
sbToken := CkStringBuilder_Create();
CkStringBuilder_LoadFile(sbToken,'qa_data/tokens/googleCloudStorageAccessToken.txt','utf-8');

// ---- Step 1
// Create the JSON body of the PUT request that will be sent.

// {
//   "storageClass": "[STORAGE_CLASS]"
// }
// 

json := CkJsonObject_Create();
// Be careful if using the "regional" storage class.  See the note below about the 400 error response.
CkJsonObject_UpdateString(json,'storageClass','nearline');

// ---- Step 2
// Send a PUT equivalent to this curl command

// curl -X PUT --data-binary @[JSON_FILE_NAME].json \
//     -H "Authorization: Bearer [OAUTH2_TOKEN]" \
//     -H "Content-Type: application/json" \
//     "https://www.googleapis.com/storage/v1/b/[BUCKET_NAME]?fields=storageClass"

http := CkHttp_Create();
CkHttp_putAuthToken(http,CkStringBuilder__getAsString(sbToken));

CkHttp_SetUrlVar(http,'bucket_name','chilkat-ocean');
url := 'https://www.googleapis.com/storage/v1/b/{$bucket_name}?fields=storageClass';
resp := CkHttp_PText(http,'PUT',url,CkJsonObject__emit(json),'utf-8','application/json',False,False);
if (CkHttp_getLastMethodSuccess(http) = False) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

responseCode := CkHttpResponse_getStatusCode(resp);
if (responseCode = 401) then
  begin
    Memo1.Lines.Add(CkHttpResponse__bodyStr(resp));
    Memo1.Lines.Add('If invalid credentials, then it is likely the access token expired.');
    Memo1.Lines.Add('Your app should automatically fetch a new access token and re-try.');
    CkHttpResponse_Dispose(resp);
    Exit;
  end;

// On my first try at running this code, I received the following error response:
// Response code: 400
// Response body
// {
//  "error": {
//   "errors": [
//    {
//     "domain": "global",
//     "reason": "invalid",
//     "message": "The combination of locationConstraint and storageClass you provided is not supported for your project"
//    }
//   ],
//   "code": 400,
//   "message": "The combination of locationConstraint and storageClass you provided is not supported for your project"
//  }
// }
// 

// This was because my storage location was a Multi-regional location, and I tried to assign the "regional" storage class,
// which is not allowed. 

Memo1.Lines.Add('Response code: ' + IntToStr(responseCode));
Memo1.Lines.Add('Response body');
Memo1.Lines.Add(CkHttpResponse__bodyStr(resp));

// A response code = 200 indicates success, and the response body contains the JSON
// 
// Response code: 200
// Response body
// {
//  "storageClass": "NEARLINE"
// }
// 

CkHttpResponse_Dispose(resp);

CkStringBuilder_Dispose(sbToken);
CkJsonObject_Dispose(json);
CkHttp_Dispose(http);

end;