diff --git a/Build/MQTTnet.nuspec b/Build/MQTTnet.nuspec index c5a85b9..0701cee 100644 --- a/Build/MQTTnet.nuspec +++ b/Build/MQTTnet.nuspec @@ -22,6 +22,7 @@ * [Server] Added interceptor for unsubscriptions. * [MQTTnet.Server] Added interceptor for unsubscriptions. * [MQTTnet.AspNetCore] improved compatibility with AspNetCore 3.1 +* [Core] Added MqttApplicationMessage.GetUserProperty() convenience method (thanks to @PMExtra). * [Client] Support WithConnectionUri to configure client (thanks to @PMExtra). * [Server] Removed exceptions when user properties are set with MQTT protocol version 3.1 diff --git a/Source/MQTTnet/Extensions/UserPropertyExtension.cs b/Source/MQTTnet/Extensions/UserPropertyExtension.cs new file mode 100644 index 0000000..5bb28cf --- /dev/null +++ b/Source/MQTTnet/Extensions/UserPropertyExtension.cs @@ -0,0 +1,32 @@ +using System; +using System.ComponentModel; +using System.Linq; + +namespace MQTTnet.Extensions +{ + public static class UserPropertyExtension + { + public static string GetUserProperty(this MqttApplicationMessage message, string propertyName, StringComparison comparisonType = StringComparison.OrdinalIgnoreCase) + { + if (message == null) throw new ArgumentNullException(nameof(message)); + if (propertyName == null) throw new ArgumentNullException(nameof(propertyName)); + + return message.UserProperties?.SingleOrDefault(up => up.Name.Equals(propertyName, comparisonType))?.Value; + } + + public static T GetUserProperty(this MqttApplicationMessage message, string propertyName, StringComparison comparisonType = StringComparison.OrdinalIgnoreCase) + { + var value = GetUserProperty(message, propertyName, comparisonType); + + var typeDescriptor = TypeDescriptor.GetConverter(typeof(T)); + try + { + return (T) typeDescriptor.ConvertFromString(value); + } + catch (Exception ex) + { + throw new InvalidOperationException($"Cannot convert value({value ?? "null"}) of UserProperty({propertyName}) to {typeof(T).FullName}.", ex); + } + } + } +} diff --git a/Source/MQTTnet/MQTTnet.csproj b/Source/MQTTnet/MQTTnet.csproj index 28e3f3d..07b9161 100644 --- a/Source/MQTTnet/MQTTnet.csproj +++ b/Source/MQTTnet/MQTTnet.csproj @@ -42,6 +42,7 @@ + diff --git a/Tests/MQTTnet.Core.Tests/MqttApplicationMessage_Tests.cs b/Tests/MQTTnet.Core.Tests/MqttApplicationMessage_Tests.cs new file mode 100644 index 0000000..6b791dc --- /dev/null +++ b/Tests/MQTTnet.Core.Tests/MqttApplicationMessage_Tests.cs @@ -0,0 +1,33 @@ +using System; +using System.Collections.Generic; +using Microsoft.VisualStudio.TestTools.UnitTesting; +using MQTTnet.Extensions; +using MQTTnet.Packets; + +namespace MQTTnet.Tests +{ + [TestClass] + public class MqttApplicationMessage_Tests + { + [TestMethod] + public void GetUserProperty_Test() + { + var message = new MqttApplicationMessage + { + UserProperties = new List + { + new MqttUserProperty("foo", "bar"), + new MqttUserProperty("value", "1011"), + new MqttUserProperty("CASE", "insensitive") + } + }; + + Assert.AreEqual("bar", message.GetUserProperty("foo")); + Assert.AreEqual(1011, message.GetUserProperty("value")); + Assert.AreEqual("insensitive", message.GetUserProperty("case")); + Assert.AreEqual(null, message.GetUserProperty("nonExists")); + Assert.AreEqual(null, message.GetUserProperty("nonExists")); + Assert.ThrowsException(() => message.GetUserProperty("nonExists")); + } + } +}