(Delphi DLL) curl with OAuth2 Client Credentials

See more CURL Examples

This example shows how to run a simple CURL command with an OAuth2 access token for authorization. We use CURL to retrieve a SharePoint site ID, and Chilkat automatically fetches the OAuth2 access token using the provided credentials.

Note: This example requires Chilkat v11.5.0 or greater.

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, StringBuilder, HttpCurl, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
sb: HCkStringBuilder;
jsonOAuth2: HCkJsonObject;
httpCurl: HCkHttpCurl;
responseJson: HCkJsonObject;
statusCode: Integer;

begin
success := False;

// This example will run the following curl command

// curl -X GET "https://graph.microsoft.com/v1.0/sites/{{sharepoint_hostname}}:/sites/{{site_name}}" \
//   -H "Authorization: Bearer ACCESS_TOKEN" \
//   -H "Accept: application/json"

sb := CkStringBuilder_Create();
CkStringBuilder_AppendLn(sb,'curl -X GET "https://graph.microsoft.com/v1.0/sites/{{sharepoint_hostname}}:/sites/{{site_name}}" \");
CkStringBuilder_AppendLn(sb,'  -H "Authorization: Bearer ACCESS_TOKEN" \");
CkStringBuilder_AppendLn(sb,'  -H "Accept: application/json"');

// Build the JSON that provides information for getting the OAuth2 access token using the OAuth2 client credentials flow.
jsonOAuth2 := CkJsonObject_Create();

CkJsonObject_UpdateString(jsonOAuth2,'oauth2.client_id','CLIENT_ID');
CkJsonObject_UpdateString(jsonOAuth2,'oauth2.client_secret','CLIENT_SECRET');
CkJsonObject_UpdateString(jsonOAuth2,'oauth2.scope','https://graph.microsoft.com/.default');
CkJsonObject_UpdateString(jsonOAuth2,'oauth2.token_endpoint','https://login.microsoftonline.com/TENANT_ID/oauth2/v2.0/token');

httpCurl := CkHttpCurl_Create();

// Provide the information for getting the OAuth2 access token from the token endpoint
// Note: The Authorization header specified in the curl command will be ignored and replaced using the OAuth2 access token obtained at runtime from the token endpoint.
CkHttpCurl_SetAuth(httpCurl,jsonOAuth2);

// The placeholders {{sharepoint_hostname}} and {{site_name}} represent variables that must be defined before execution.
// When DoYourThing runs the curl command, it automatically substitutes these placeholders with their corresponding values.
// Below are the values assigned to these variables:
CkHttpCurl_SetVar(httpCurl,'sharepoint_hostname','example.sharepoint.com');
CkHttpCurl_SetVar(httpCurl,'site_name','test');

// Run the curl command.
success := CkHttpCurl_DoYourThing(httpCurl,CkStringBuilder__getAsString(sb));
if (success = False) then
  begin
    Memo1.Lines.Add(CkHttpCurl__lastErrorText(httpCurl));
    Exit;
  end;

responseJson := CkJsonObject_Create();
CkJsonObject_putEmitCompact(responseJson,False);

CkHttpCurl_GetResponseJson(httpCurl,responseJson);

statusCode := CkHttpCurl_getStatusCode(httpCurl);
Memo1.Lines.Add('response status code: ' + IntToStr(statusCode));

Memo1.Lines.Add(CkJsonObject__emit(responseJson));

CkStringBuilder_Dispose(sb);
CkJsonObject_Dispose(jsonOAuth2);
CkHttpCurl_Dispose(httpCurl);
CkJsonObject_Dispose(responseJson);

end;