// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.app.discover;

[Discoverable]
protocol ModuleOutputWriter {
    /// Writes the `entity_reference` to the module's `output_parameter_name`
    /// output. If no entity is provided, the output will be unset.
    /// Return happens upon completion of a successful write.
    Write(string output_name, string? entity_reference) -> () error OutputError;
};

/// Errors that can occur when writing to an output.
enum OutputError : int32 {
    /// If the output doesn't match a parameter defined in the module manifest
    /// for the action currently being handled by the module.
    UNKNOWN_NAME = 1;

    /// If the entity reference couldn't be resolved.
    UNKNOWN_ENTITY_REFERENCE = 2;

    /// If the entity type written doesn't match the type defined in the module
    /// manifest for the action currently being handled by the module..
    INVALID_ENTITY_TYPE = 3;
};