EFDynamicSortingAndFiltering

Playing around with expression generation for query filtering and sorting with Entity Framework Core.

This is definitely over engineered, and most likely not the best approach the majority of times, but something similar to the HardcodedPropertyTypeInferringFilteringStrategy and HardcodedPropertyTypeInferringSortingStrategy strategies was useful in a past project to ease the development of a bunch of pages with grids.

I added here ReflectionBasedPropertyTypeInferringFilteringStrategy and ReflectionBasedPropertyTypeInferringSortingStrategy to see how much more generic the original code could be made, and what impact would it have on performance.

Using it

Filtering

The usual:

await _ctx.SampleEntities.Where(e => e.Id == 2).ToListAsync();

Translates into:

await _ctx.SampleEntities.Filter(new Filter { Type = FilterType.Equals, PropertyName = nameof(SampleEntity.Id), Values = new[] { "2" } }).ToListAsync();

It's much more verbose, but the goal is to create the Filter based on string based info (like info got in a AJAX request).

Sorting

The usual:

await _ctx.SampleEntities.OrderByDescending(e => e.SomeNullableInt).ToListAsync();

Translates into:

await _ctx.SampleEntities.Sort(new SortCriteria { PropertyName = nameof(SampleEntity.SomeNullableInt), Direction = SortDirection.Descending }).ToListAsync();

Like in the filtering case, it's much more verbose, but the goal is to create the SortCriteria based on string based info (like info got in a AJAX request).

Testing

Running a docker container with postgres for tests docker run -p 5432:5432 --restart unless-stopped --name postgres -e POSTGRES_USER=user -e POSTGRES_PASSWORD=pass -d postgres

Got better ideas?

This was useful for me in the past, but I'm sure there are better ways, or at least ways to improve this, so if you've got any suggestion, please share!