DataBind Controls to Todoist Data in Delphi

The CData ODBC Driver for Todoist supports the ODBC standard to enable integration of live Todoist data with visual form designers and other rapid development tools in Delphi. The ODBC driver simplifies data access strategies for applications that share a single codebase like Delphi by providing a single API for database development. This article shows how to how to connect to Todoist data and query data from a simple visual component library (VCL) application, as well as from Delphi code.

Create a Connection to Todoist 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.

Start by setting the Profile connection property to the location of the Todoist Profile on disk (e.g. C:\profiles\Todoist.apip). Next, set the ProfileSettings connection property to the connection string for Todoist (see below).

Todoist API Profile Settings

To authenticate to Todoist, and connect to your own data or to allow other users to connect to their data, you can use the OAuth standard.

First, you will need to register an OAuth application with Todoist. To do so, go to App Management Console, create a new application and configure a valid OAuth redirect URL. Your Oauth application will be assigned a client id and a client secret.

After setting the following connection properties, you are ready to connect:

• AuthScheme: Set this to OAuth.
• InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to manage the process to obtain the OAuthAccessToken.
• OAuthClientId: Set this to the client_id that is specified in you app settings.
• OAuthClientSecret: Set this to the client_secret that is specified in you app settings.
• CallbackURL: Set this to the Redirect URI that is specified in your app settings

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

Create VCL Applications with Connectivity to Todoist Data

Follow the procedure below to start executing queries to Todoist 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 Todoist 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 Id, Priority FROM Tasks WHERE Completed = 'false'
   • 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.

Execute Commands to Todoist with FireDAC Components

You can use the TFDConnection and TFQuery components to execute queries to Todoist data. This section provides Todoist data-specific examples of executing queries with the TFQuery component.

Connect to Todoist Data

To connect to the data source, set the Connected property of the TFDConnection component to true. You can set the same properties from code:

Create Parameterized Queries

Parameterized resources can improve performance: Preparing statements is costly in system resources and time. The connection must be active and open while a statement is prepared. By default, FireDAC prepares the query to avoid recompiling the same query over and over. To disable statement preparation, set ResourceOptions.DirectExecute to True; for example, when you need to execute a query only once.

Execute a Query

To execute a query that returns a result set, such as a select query, use the Open method. The Open method executes the query, returns the result set, and opens it. The Open method will return an error if the query does not produce a result set.