ff1f0833ad
* Restore EF Core persistence layer Originally, we had moved EF Core to the extensions repo, but in practice this turned out to be rather impractical when debugging elsa-core, given that we would lose all of the state (workflow definitions, instances, etc.) across application restarts. * Integrate PostgreSQL support into EF Core persistence and enhance BlobStorage workflows provider setup.
59 lines
2.6 KiB
C#
59 lines
2.6 KiB
C#
using System.Linq.Expressions;
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using Elsa.Extensions;
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// ReSharper disable once CheckNamespace
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namespace Elsa.Persistence.EFCore.Extensions;
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/// <summary>
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/// Provides extension methods for <see cref="Expression"/> objects.
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/// </summary>
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public static class ExpressionExtensions
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{
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/// <summary>
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/// Builds an expression that checks if the specified property is contained in the specified list of entities.
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/// </summary>
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/// <param name="keySelector">The key selector.</param>
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/// <param name="entities">The entities.</param>
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/// <typeparam name="TEntity">The type of the entity.</typeparam>
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/// <returns>The expression.</returns>
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public static Expression<Func<TEntity, bool>> BuildContainsExpression<TEntity>(this Expression<Func<TEntity, string>> keySelector, IEnumerable<TEntity> entities) where TEntity : class
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{
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var compiledKeySelector = keySelector.Compile();
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var list = entities.Select(compiledKeySelector).ToList();
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var property = keySelector.GetProperty()!;
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var param = Expression.Parameter(typeof(TEntity));
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var body = Expression.Call(
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typeof(Enumerable),
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"Contains",
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new[] {compiledKeySelector.Method.ReturnType},
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Expression.Constant(list), Expression.Property(param, property));
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return Expression.Lambda<Func<TEntity, bool>>(body, param);
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}
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/// <summary>
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/// Builds an expression that checks if the specified property is equal to the specified entity's property.
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/// </summary>
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/// <param name="keySelector">The key selector.</param>
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/// <param name="entity">The entity.</param>
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/// <typeparam name="TEntity">The type of the entity.</typeparam>
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/// <returns>The expression.</returns>
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public static Expression<Func<TEntity, bool>> BuildEqualsExpression<TEntity>(this Expression<Func<TEntity, string>> keySelector, TEntity entity)
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{
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var keyName = keySelector.GetProperty()!.Name;
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// Define parameters for the lambda expression
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var parameter = Expression.Parameter(typeof(TEntity), "x");
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var keySelectorLambda = Expression.Lambda<Func<TEntity, string>>(Expression.Property(parameter, keyName), parameter);
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// Build the expression that compares the keys
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var entityKey = keySelectorLambda.Compile()(entity);
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var comparison = Expression.Equal(keySelectorLambda.Body, Expression.Constant(entityKey));
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// Create the final lambda expression that can be used in AnyAsync
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var lambda = Expression.Lambda<Func<TEntity, bool>>(comparison, parameter);
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return lambda;
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}
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} |