1#region Copyright notice and license
2// Protocol Buffers - Google's data interchange format
3// Copyright 2008 Google Inc.  All rights reserved.
4// https://developers.google.com/protocol-buffers/
5//
6// Redistribution and use in source and binary forms, with or without
7// modification, are permitted provided that the following conditions are
8// met:
9//
10//     * Redistributions of source code must retain the above copyright
11// notice, this list of conditions and the following disclaimer.
12//     * Redistributions in binary form must reproduce the above
13// copyright notice, this list of conditions and the following disclaimer
14// in the documentation and/or other materials provided with the
15// distribution.
16//     * Neither the name of Google Inc. nor the names of its
17// contributors may be used to endorse or promote products derived from
18// this software without specific prior written permission.
19//
20// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31#endregion
32
33using System;
34using System.Collections;
35
36namespace Google.Protobuf.Reflection
37{
38    /// <summary>
39    /// Allows fields to be reflectively accessed.
40    /// </summary>
41    public interface IFieldAccessor
42    {
43        /// <summary>
44        /// Returns the descriptor associated with this field.
45        /// </summary>
46        FieldDescriptor Descriptor { get; }
47
48        /// <summary>
49        /// Clears the field in the specified message. (For repeated fields,
50        /// this clears the list.)
51        /// </summary>
52        void Clear(IMessage message);
53
54        /// <summary>
55        /// Fetches the field value. For repeated values, this will be an
56        /// <see cref="IList"/> implementation. For map values, this will be an
57        /// <see cref="IDictionary"/> implementation.
58        /// </summary>
59        object GetValue(IMessage message);
60
61        /// <summary>
62        /// Indicates whether the field in the specified message is set.
63        /// For proto3 fields that aren't explicitly optional, this throws an <see cref="InvalidOperationException"/>
64        /// </summary>
65        bool HasValue(IMessage message);
66
67        /// <summary>
68        /// Mutator for single "simple" fields only.
69        /// </summary>
70        /// <remarks>
71        /// Repeated fields are mutated by fetching the value and manipulating it as a list.
72        /// Map fields are mutated by fetching the value and manipulating it as a dictionary.
73        /// </remarks>
74        /// <exception cref="InvalidOperationException">The field is not a "simple" field.</exception>
75        void SetValue(IMessage message, object value);
76    }
77}