service-model/operationContext.js

An object oriented web service framework inspired by Windows Communication Foundation.

var domain = require("domain");
var messageHeaders_1 = require("./messageHeaders");
/**
 * Provides information about the context of the current operation.
 *
 * The OperationContext is used to find out information about the request that trigger the current operation. The
 * operation context can also be used to store information associated with a particular operation across async gaps.
 *
 * In order to store data associated with the current operation across async gaps, a domain is created during
 * operation invocation. This has the added benefit of being able to capture exceptions and route them through the error
 * handling pipeline.
 *
 * Note that if unhandled exceptions are caught, the [[RequestDispatcher]] should be closed by calling [[close]] and the
 * process should exit once all pending operations have completed. (This is indicated by the `closed`
 * event on the [[RequestDispatcher]].) See the [node documentation](https://nodejs.org/api/domain.html) for more
 * information.
 *
 * Creation of an OperationContext is disabled by default. It is be enabled for a service by setting
 * [[createOperationContext]] to true on the [[DispatchService]]. This can be accomplished by adding the [[Service]]
 * decorator to the service implementation:
 *
 * ```typescript
 * @Service({ createOperationContext: true })
 * @Contract("Calculator")
 * class CalculatorService {
 *     ...
 * }
 * ```
 *
 * Note that [domains have been deprecated](https://github.com/nodejs/node/issues/66) in Node.js and will be removed in
 * the future. According to the discussion referenced above, they will not be removed until a viable alternative is
 * introduced. However, this may introduce breaking changes in the usage of OperationContext.
 */
var OperationContext = (function () {
    function OperationContext() {
        /**
         * Dictionary of values associated with the OperationContext. Can be used to share data between functions within
         * the context of the execution of an operation.
         */
        this.items = new Map();
        /**
         * Outgoing headers to be added to HTTP response. Note that the headers are not added if a fault is returned or for
         * one-way operations.
         */
        this.outgoingHeaders = new messageHeaders_1.MessageHeaders();
    }
    Object.defineProperty(OperationContext, "current", {
        /**
         * Gets the OperationContext associated with the active domain. Throws an error if there is not an active domain.
         */
        get: function () {
            return OperationContext._activeDomain().__operation_context__;
        },
        /**
         * Sets the OperationContext associated with the active domain. Throws an error if there is not an active domain.
         * @param context The current context.
         */
        set: function (context) {
            OperationContext._activeDomain().__operation_context__ = context;
        },
        enumerable: true,
        configurable: true
    });
    /**
     * Returns the active domain.
     * @hidden
     */
    OperationContext._activeDomain = function () {
        var active = domain.active;
        if (!active) {
            throw new Error("There is not an active domain.");
        }
        return active;
    };
    return OperationContext;
})();
exports.OperationContext = OperationContext;