FluentFilterForge 1.0.2

FluentFilterForge

A strongly-typed, fluent filter builder for .NET. Build composable, null-safe filter predicates using a readable API and apply them to any IEnumerable<T> or IQueryable<T> source.

Features

• Fluent API – chain Where(…).And(…).Or(…) conditions naturally
• Type-safe – dedicated builders for bool, numbers, string, char, Guid, date/time types, enums, and collections
• Negation – call .Not() before any condition to invert it
• Nested groups – pass a delegate to AndGroup(…) / OrGroup(…) to create grouped sub-conditions
• Collection filters – Any(…) and All(…) with a full sub-filter on element level
• IQueryable support – expressions are handed directly to the query provider (e.g. Entity Framework Core) for server-side evaluation

Installation

dotnet add package FluentFilterForge

Quick start

using FluentFilterForge;

var filter = Filter.For<Product>()
    .Where(p => p.Price).GreaterThanOrEqual(10m)
    .And(p => p.Name).StartsWith("Pro")
    .And(p => p.IsActive).IsTrue()
    .Build();

// IEnumerable<T>
var results = products.Where(filter).ToList();

// IQueryable<T> (e.g. Entity Framework Core)
var results = await dbContext.Products.Where(filter).ToListAsync();

Supported operators

Boolean (bool / bool?)

Numbers (int, long, decimal, double, … and their nullable counterparts)

String (string?)

Guid (Guid / Guid?)

Date/time types (DateTime, DateOnly, TimeOnly, DateTimeOffset, TimeSpan and nullable variants)

Custom types and enums

Collections (IEnumerable<TElement>)

Negation

Call .Not() directly after .Where(…) before specifying the condition:

var filter = Filter.For<Order>()
    .Where(o => o.Status).Not().Equal(OrderStatus.Cancelled)
    .And(o => o.Total).Not().LessThan(50m)
    .Build();

Grouped sub-conditions

Pass a delegate to AndGroup(…) or OrGroup(…) to create a nested group:

var filter = Filter.For<Product>()
    .Where(p => p.IsActive).IsTrue()
    .AndGroup(nested => nested
        .Where(p => p.Category).Equal("Electronics")
        .Or(p => p.Category).Equal("Computers"))
    .Build();
// → IsActive == true AND (Category == "Electronics" OR Category == "Computers")

Collection sub-filters

var filter = Filter.For<Order>()
    .Where(o => o.Tags).Any(tags => tags
        .Where(tag => tag).Equal("priority"))
    .Build();

Using with Entity Framework Core

IFilter<T> produces an Expression<Func<T, bool>> via ToExpression(), which EF Core translates to SQL:

var filter = Filter.For<Customer>()
    .Where(c => c.Country).Equal("DE")
    .And(c => c.CreatedAt).GreaterThanOrEqual(DateTime.UtcNow.AddYears(-1))
    .Build();

var customers = await dbContext.Customers
    .Where(filter)
    .OrderBy(c => c.Name)
    .ToListAsync();

License

MIT