18.4.1 About REST Data Sources

REST Data Sources enable developers to access to Representational State Transfer (REST) services or generic JSON data feeds in applications and use the data in Application Express components such as reports, interactive reports, and interactive grids.

A REST Data Source can contain one or many Operations which are the references to a concrete external web service. Configurations at the REST source level are shared across all contained operations.

How REST Data Sources Differ from Legacy Web Service References

Unlike Legacy Web Service References, a REST Data Source contains metadata about the Web service which can be used by Application Express Components or PL/SQL processes to invoke the service and to process the responses.

REST Data Sources contain multiple operators that differ depending upon the Web service target. For a REST services, an operation is a specific service handler (such as, GET, PUT, POST, or DELETE). Developers assign Operation a Database Action such as Fetch Multiple Rows, Fetch Single Row, Insert Row, Update Row, and Delete Row. However, you can assign each Database Operation only once to a REST Data Source Operation.

Integration with Application Express Components

Oracle Application Express provides direct integration of REST Data Sources in classic reports, interactive reports, CSS Calendar, and JET Charts.

About Remote Servers

Oracle Application Express splits the endpoint URL of a Web Service into two parts. The server-specific part is stored as a separate entity called the Remote Server. You can reuse a Remote Server with multiple REST Data Sources if it uses the same server, port and URL Path Prefix (context root).

If you change the attributes of a Remote Server, the change impacts all REST Data Sources using the Remote Server. Remote Servers make it easy to move a collection of REST Data Sources. For example, you can move from test system to a production system by changing the URL within the Remote Server object.

About Authentication and Credentials

REST Data Sources supports various authentication types. Authentication credentials can be specified at the Remote Server-level for all REST Data Sources using the Remote Server). If credentials are set at the REST Data Source-level, that setting supersedes credentials stored at the Remote Server level.

A Credential denotes the Authentication method, a Client ID (or user name) and a Client Secret (or password). Credentials are stored as a named entity within Shared Components and can be re-used across multiple REST Data Sources or Remote Servers.

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