To add a REST Web service connection, use the following steps.
This example assumes that you have a list named Tasks, which includes some dummy entries.
1. With your site open in SharePoint Designer, click the Data Source tab in the left-hand navigation pane.
2. In the Data Sources tab, click REST Service Connection in the New group in the ribbon.
3. In the Data Source Properties dialog, enter the information as shown in Figure 19.59 and then click OK to save the REST data connection. Back in the Data Sources tab, the new REST connection should be visible under the RSS, REST, Server Scripts section.