53 lines
1.9 KiB
C#
53 lines
1.9 KiB
C#
using System;
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using System.Collections.Generic;
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using System.Linq;
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using System.Reflection;
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namespace BinaryDad.AggregateDal
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{
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public class AggregateDataAccess<T> where T : class
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{
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private static ICollection<Type> dataAccessTypes;
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static AggregateDataAccess() => LoadInstances();
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/// <summary>
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/// Invokes a method for all instances of <typeparamref name="T"/>
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/// </summary>
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/// <typeparam name="TResult"></typeparam>
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/// <param name="func"></param>
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/// <returns></returns>
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protected TResult Invoke<TResult>(Func<T, TResult> func)
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{
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var results = new List<TResult>();
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foreach (var dataAccessType in dataAccessTypes)
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{
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var instance = Activator.CreateInstance(dataAccessType) as T;
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results.Add(func(instance));
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}
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// if the "EF" version invokes first, return that value
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return results.FirstOrDefault(r => !r.Equals(default(T)));
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}
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private static void LoadInstances()
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{
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if (dataAccessTypes == null)
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{
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var type = typeof(T);
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var aggregateType = typeof(AggregateDataAccess<T>);
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// load all types except for 1) the interface itself, 2) any interface, and 3) is not implementing AggregateDataAccess<T>
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// NOTE: the "EF" version will load first, allowing for the "QuickBase" version to run last, in a separate thread if desired
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dataAccessTypes = Assembly.GetExecutingAssembly()
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.ExportedTypes
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.Where(t => type.IsAssignableFrom(t) && !t.IsInterface && !aggregateType.IsAssignableFrom(t))
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.OrderBy(t => t.Name.StartsWith("QuickBase", StringComparison.OrdinalIgnoreCase))
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.ToList();
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}
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}
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}
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}
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