How Can I Automatically Eager Load All Nested Entities in Entity Framework Core 2.0.1?

Auto-Eager Loading in Entity Framework Core 2.0.1

Context:

When eager loading related entities in Entity Framework Core, users may face issues when nested entities remain unpopulated. This issue necessitates the manual inclusion of each related entity, which becomes impractical for complex entity relationships.

Problem:

Users need a way to automatically eager load all nested related entities in Entity Framework Core 2.0.1, eliminating the need for explicit inclusion using Include() and ThenInclude().

Solution:

Custom Extensions:

As this feature is not natively supported in EF Core 2.0.1, custom extension methods can be employed:

public static partial class CustomExtensions
{
    public static IQueryable<T> Include<T>(this IQueryable<T> source, IEnumerable<string> navigationPropertyPaths)
        where T : class
    {
        return navigationPropertyPaths.Aggregate(source, (query, path) => query.Include(path));
    }

    public static IEnumerable<string> GetIncludePaths(this DbContext context, Type clrEntityType, int maxDepth = int.MaxValue)
    {
        // Implementation for recursive traversal and path collection
    }
}

Usage in Generic Repository:

In the generic repository's GetAllAsync() method, the GetIncludePaths() extension can be utilized to automatically determine and include all related entities:

public virtual async Task<IEnumerable<T>> GetAllAsync(Expression<Func<T, bool>> predicate = null)
{
    var query = Context.Set<T>()
        .Include(Context.GetIncludePaths(typeof(T)));
    if (predicate != null)
        query = query.Where(predicate);
    return await query.ToListAsync();
}

Additional Notes:

• This approach is compatible with EF Core 2.0.1, which lacks the "rule-based eager load" feature released in later versions.
• Using these extensions, entities can be loaded with all their nested relationships automatically, simplifying data retrieval.

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