48 lines
1.7 KiB
C#
48 lines
1.7 KiB
C#
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using System;
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using Microsoft.EntityFrameworkCore;
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using System.Linq;
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using System.Linq.Expressions;
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namespace Start.Server {
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/// <summary>Extension methods for LINQ queries</summary>
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public static class LinqExtensions {
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/// <summary>
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/// If <paramref name="condition"/> is true, then returns <c>query.Where(expression)</c>.
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/// Otherwise returns the <paramref name="query"/> unchanged.
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/// </summary>
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/// <param name="query">The query to potentially apply the expression to</param>
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/// <param name="condition">
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/// Determines whether or not the expression should be applied
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/// </param>
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/// <param name="expression">A function to test each element</param>
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public static IQueryable<T> IfWhere<T>(this IQueryable<T> query, bool condition,
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Expression<Func<T, bool>> expression) {
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if (condition)
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return query.Where(expression);
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return query;
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}
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/// <summary>
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/// If the <paramref name="condition"/> is true, apply the <paramref name="transform"/> to
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/// the query, otherwise return the query unchanged.
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/// </summary>
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/// <typeparam name="T">The <paramref name="query"/>'s type</typeparam>
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/// <param name="query">The query to potentially transform</param>
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/// <param name="condition">
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/// If true, apply the <paramref name="transform"/> to the <paramref name="query"/>
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/// </param>
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/// <param name="transform">
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/// A function to apply to the <paramref name="query"/> if the <paramref name="condition"/>
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/// is true
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/// </param>
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public static IQueryable<T> If<T>(this IQueryable<T> query, bool condition,
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Func<IQueryable<T>, IQueryable<T>> transform) {
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if (condition)
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return transform(query);
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return query;
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}
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}
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}
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