1 // Licensed to the .NET Foundation under one or more agreements. 2 // The .NET Foundation licenses this file to you under the MIT license. 3 // See the LICENSE file in the project root for more information. 4 5 using System.Dynamic.Utils; 6 7 namespace System.Dynamic 8 { 9 /// <summary> 10 /// Represents the dynamic get member operation at the call site, providing the binding semantic and the details about the operation. 11 /// </summary> 12 public abstract class GetMemberBinder : DynamicMetaObjectBinder 13 { 14 /// <summary> 15 /// Initializes a new instance of the <see cref="GetMemberBinder" />. 16 /// </summary> 17 /// <param name="name">The name of the member to get.</param> 18 /// <param name="ignoreCase">true if the name should be matched ignoring case; false otherwise.</param> GetMemberBinder(string name, bool ignoreCase)19 protected GetMemberBinder(string name, bool ignoreCase) 20 { 21 ContractUtils.RequiresNotNull(name, nameof(name)); 22 23 Name = name; 24 IgnoreCase = ignoreCase; 25 } 26 27 /// <summary> 28 /// The result type of the operation. 29 /// </summary> 30 public override sealed Type ReturnType => typeof(object); 31 32 /// <summary> 33 /// Gets the name of the member to get. 34 /// </summary> 35 public string Name { get; } 36 37 /// <summary> 38 /// Gets the value indicating if the string comparison should ignore the case of the member name. 39 /// </summary> 40 public bool IgnoreCase { get; } 41 42 /// <summary> 43 /// Performs the binding of the dynamic get member operation if the target dynamic object cannot bind. 44 /// </summary> 45 /// <param name="target">The target of the dynamic get member operation.</param> 46 /// <returns>The <see cref="DynamicMetaObject"/> representing the result of the binding.</returns> FallbackGetMember(DynamicMetaObject target)47 public DynamicMetaObject FallbackGetMember(DynamicMetaObject target) 48 { 49 return FallbackGetMember(target, null); 50 } 51 52 /// <summary> 53 /// When overridden in the derived class, performs the binding of the dynamic get member operation if the target dynamic object cannot bind. 54 /// </summary> 55 /// <param name="target">The target of the dynamic get member operation.</param> 56 /// <param name="errorSuggestion">The binding result to use if binding fails, or null.</param> 57 /// <returns>The <see cref="DynamicMetaObject"/> representing the result of the binding.</returns> FallbackGetMember(DynamicMetaObject target, DynamicMetaObject errorSuggestion)58 public abstract DynamicMetaObject FallbackGetMember(DynamicMetaObject target, DynamicMetaObject errorSuggestion); 59 60 /// <summary> 61 /// Performs the binding of the dynamic get member operation. 62 /// </summary> 63 /// <param name="target">The target of the dynamic get member operation.</param> 64 /// <param name="args">An array of arguments of the dynamic get member operation.</param> 65 /// <returns>The <see cref="DynamicMetaObject"/> representing the result of the binding.</returns> Bind(DynamicMetaObject target, params DynamicMetaObject[] args)66 public sealed override DynamicMetaObject Bind(DynamicMetaObject target, params DynamicMetaObject[] args) 67 { 68 ContractUtils.RequiresNotNull(target, nameof(target)); 69 ContractUtils.Requires(args == null || args.Length == 0, nameof(args)); 70 71 return target.BindGetMember(this); 72 } 73 74 /// <summary> 75 /// Always returns <c>true</c> because this is a standard <see cref="DynamicMetaObjectBinder"/>. 76 /// </summary> 77 internal override sealed bool IsStandardBinder => true; 78 } 79 } 80