1.1.6 Capabilities Provider

An environment host must implement IExtensionCapabilityProvider, and must provide all available extension capabilities through it.

IExtensionCapabilityProvider allows a host to determine whether certain extension capabilities should be enabled. The mechanisms by which a capability provider decides are implementation-dependent. They may include, but are not restricted to, the validation of an active subscription to the extended capabilities.

Denied Capabilities

All platform extensions must gracefully handle being denied their extended capabilities by the capability provider. Graceful handling includes:

• TRACE output acknowledging the denied capabilities;
• responding to an LSP shutdown request;
• cleanly terminating upon an LSP exit notification from the environment host.

An abstract server application in the SDK, RDCoreServerApp, should handle these lifecycle events correctly, without further configuration.

Capability registration	Outcome
The extension registers at least one capability.	Its process continues to run, and may handle a reduced set of LSP requests and notifications.
The extension registers no capability.	The environment host requests the termination of the extension server process.

RDCore Platform Cloud Infrastructure

First-party and third-party extensions distributed through the RDCore Platform Cloud Infrastructure may use a capability provider. That capability provider may validate the availability of certain advanced capabilities by:

• requiring 2FA authentication;
• validating an active subscription (free or paid);
• validating the signed build against the certified distribution channel build.

Platform capabilities and their exchange between processes are described in RD-VBAL §2.0.2 Client/Server Capabilities.

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⏮️ RD-VBAL §1.1.5 Extension Manifest | ⏭️ RD-VBAL §2.0 RD-VBA Computational Environment