60 lines
3.4 KiB
C#
60 lines
3.4 KiB
C#
using System;
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namespace EmbedIO.Sessions
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{
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/// <summary>
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/// Provides extension methods for types implementing <see cref="ISession"/>.
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/// </summary>
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public static class SessionExtensions
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{
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/// <summary>Gets the value associated with the specified key.</summary>
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/// <typeparam name="T">The desired type of the value.</typeparam>
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/// <param name="this">The <see cref="ISession"/> on which this method is called.</param>
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/// <param name="key">The key whose value to get from the session.</param>
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/// <param name="value">
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/// <para>When this method returns, the value associated with the specified key,
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/// if the key is found and the associated value is of type <typeparamref name="T"/>;
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/// otherwise, the default value for <typeparamref name="T"/>.</para>
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/// <para>This parameter is passed uninitialized.</para>
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/// </param>
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/// <returns><see langword="true"/> if the key is found and the associated value is of type <typeparamref name="T"/>;
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/// otherwise, <see langword="false"/>.</returns>
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/// <exception cref="NullReferenceException"><paramref name="this"/> is <see langword="null"/>.</exception>
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/// <exception cref="ArgumentNullException"><paramref name="key"/> is <see langword="null"/>.</exception>
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public static bool TryGetValue<T>(this ISession @this, string key, out T value)
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{
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if (@this.TryGetValue(key, out var foundValue) && foundValue is T typedValue)
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{
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value = typedValue;
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return true;
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}
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#pragma warning disable CS8653 // "default" can be null - We are returning false, so value is undefined
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value = default;
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#pragma warning restore CS8653
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return false;
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}
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/// <summary>Gets the value associated with the specified key.</summary>
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/// <typeparam name="T">The desired type of the value.</typeparam>
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/// <param name="this">The <see cref="ISession"/> on which this method is called.</param>
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/// <param name="key">The key whose value to get from the session.</param>
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/// <returns>The value associated with the specified key,
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/// if the key is found and the associated value is of type <typeparamref name="T"/>;
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/// otherwise, the default value for <typeparamref name="T"/>.</returns>
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public static T GetValue<T>(this ISession @this, string key)
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=> @this.TryGetValue(key, out var value) && value is T typedValue ? typedValue : default;
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/// <summary>Gets the value associated with the specified key.</summary>
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/// <typeparam name="T">The desired type of the value.</typeparam>
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/// <param name="this">The <see cref="ISession"/> on which this method is called.</param>
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/// <param name="key">The key whose value to get from the session.</param>
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/// <param name="defaultValue">The default value to return if the key is not found
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/// or its associated value is not of type <typeparamref name="T"/>.</param>
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/// <returns>The value associated with the specified key,
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/// if the key is found and the associated value is of type <typeparamref name="T"/>;
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/// otherwise, <paramref name="defaultValue"/>.</returns>
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public static T GetOrDefault<T>(this ISession @this, string key, T defaultValue)
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=> @this.TryGetValue(key, out var value) && value is T typedValue ? typedValue : defaultValue;
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}
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} |