Build a Simple VCL Application for PayPal Data

Embarcadero RAD Studio provides a development environment for Delphi and C++Builder applications. With the CData ODBC Driver for PayPal, you gain access to live PayPal data within RAD Studio, abstracting the data into tables, views, and stored procedures that can be used to retrieve PayPal data. This article will walk through connecting to PayPal and creating a simple VCL application with the Form Designer.

Create a Connection to PayPal Data

If you have not already, first specify connection properties in an ODBC DSN (data source name). This is the last step of the driver installation. You can use the Microsoft ODBC Data Source Administrator to create and configure ODBC DSNs.

The provider surfaces tables from two PayPal APIs. The APIs use different authentication methods.

• The REST API uses the OAuth standard. To authenticate to the REST API, you will need to set the OAuthClientId, OAuthClientSecret, and CallbackURL properties.
• The Classic API requires Signature API credentials. To authenticate to the Classic API, you will need to obtain an API username, password, and signature.

See the "Getting Started" chapter of the help documentation for a guide to obtaining the necessary API credentials.

To select the API you want to work with, you can set the Schema property to REST or SOAP. By default the SOAP schema will be used.

For testing purposes you can set UseSandbox to true and use sandbox credentials.

You can then follow the steps below to use the Data Explorer to create a FireDAC connection to PayPal data.

1. In a new VCL Forms application, expand the FireDAC node in the Data Explorer.
2. Right-click the ODBC Data Source node in the Data Explorer.
3. Click Add New Connection.
4. Enter a name for the connection.
5. In the FireDAC Connection Editor that appears, set the DataSource property to the name of the ODBC DSN for PayPal.

Create VCL Applications with Connectivity to PayPal Data

Follow the procedure below to start executing queries to PayPal data from a simple VCL application that displays the results of a query in a grid.

1. Drop a TFDConnection component onto the form and set the following properties:

   • ConnectionDefName: Select the FireDAC connection to PayPal data.
   • Connected: Select True from the menu and, in the dialog that appears, enter your credentials.

2. Drop a TFDQuery component onto the form and set the properties below:

   • Connection: Set this property to the TFDConnection component, if this component is not already specified.

   • SQL: Click the button in the SQL property and enter a query. For example:

     SELECT Date, GrossAmount FROM Transactions
   • Active: Set this property to true.

3. Drop a TDataSource component onto the form and set the following property:

   • DataSet: In the menu for this property, select the name of the TFDQuery component.

4. Drop a TDBGrid control onto the form and set the following property:

   • DataSource: Select the name of the TDataSource.
5. Drop a TFDGUIxWaitCursor onto the form — this is required to avoid a run-time error.

You now have an executable application that displays the results of the SQL Query set in the TFDQuery object.