FilterBuilder

A library that can be used to create dynamic filters / queries using a fluent builder

The following filters can be used interchangeable

Filter<Sample> filter = FilterBuilder.For<Sample>()
                                     .And(e => e.Name.Contains("Foo"));
                                         
Func<Sample, bool> funcFilter = FilterBuilder.For<Sample>()
                                             .And(e => e.Name.Contains("Foo"))       
                                                 
Expression<Func<Sample, bool>> expressionFilter = FilterBuilder.For<Sample>()
                                                               .And(e => e.Name.Contains("Foo"))

Usage:

and / or filters:

var sample = new List<Sample> { new Sample { Name = "foo" } };
var filter = FilterBuilder.For<Sample>()
                          .And(e => e.Name.Contains("foo"))
                          .Or(e => e.Name.Contains("moot"));

optional filters:

var sample = new List<Sample> { new Sample { Name = "foo" } };
var filter = FilterBuilder.For<Sample>()
                          .When(() => sample.IsActive)
                            .Then(e => e.IsActive == true);

combine filters:

var sample = new List<Sample> { new Sample { Name = "foo" } };
var filter = FilterBuilder.For<Sample>()
                          .And(e => e.Name.Contains("moot"));

var extendedFilter = FilterBuilder.Extend<Sample>(filter)
                                  .Or(e => e.Name.Contains("foo"));

Execution:

var filter = FilterBuilder.For<Sample>()
                          .And(e => e.Name.Contains("moot")); 
                          
//entity framework converts the expression tree to sql. The filter (as is the case with all expressions)
//should not contain code that cannot be converted to sql.
return await dbcontext.Sample
                      .Where(filter)
                      .ToListAsync();
                      
//execute func
var sample = new List<Sample> { new Sample { Name = "bla" },
                                new Sample { Name = "foo" }};
                                
var filter = FilterBuilder.For<Sample>()
                          .And(e => e.Name.Contains("bla")); 
                          
//returns a list with one matching item                  
var result = sample.Where(filter)
                   .ToList();