How to build a custom mapper for a class with a child list

[moxplod]

I am trying to build a custom mapper. I have posted my simplified classes.
I have it working using LINQ. The example query I am using is in the code below

I am trying to figure out how to do it using gridify? Ideally would like to use a query like "CustomFields[Key1]=Value1"

public class TestEntity
{    
    public string Name { get; set; }
    public List<CustomField> CustomFields { get; set; }
}

public class CustomField
{
    public string Key { get; init; }
    public string Value { get; set; }
}

 [Fact]
  public void CustomFieldFilteringTest()
  {
      var entity = new TestEntity
          {
              Name = Any.String(),
              CustomFields = new CustomFields([
                  new("Key1", "Value1"),
                  new("Key2", "Value2")
              ])
          };
      
      var dataSource = new List<TestEntity> { entity }.AsQueryable();
      
      // Using LINQ
      var linqResult = dataSource.Where(x => 
          x.CustomFields.Any(s => s.Key == "Key1" && s.Value == "Value1")).ToList();
      Assert.Single(linqResult);
      
      // HOW TO DO IT USING Gridify ??


      // var mapper = new GridifyMapper<TestEntity>();
      // mapper.AddMap("CustomFields", x => x.CustomFields.Select(s => s.Key));
      //
      // var list = dataSource.ApplyFiltering($"CustomFieldKey==Key1", mapper).ToList();
      // Assert.Single(list);
      // Assert.Equal(entity.Name, list[0].Name);
  }

[alirezanet]

Hi @moxplod,
This should work as expected

var gm = new GridifyMapper<TestEntity>()
		.AddMap("k", q => q.CustomFields.Select(cf => cf.Key))
		.AddMap("v", q => q.CustomFields.Select(cf => cf.Value));

var gridifyResult = dataSource.ApplyFiltering("k=Key1,v=Value1", gm);

[alirezanet]

Also, check out the dictionary support-related documentation here:
https://alirezanet.github.io/Gridify/guide/filtering#passing-index-key-to-sub-collections-arrays-and-dictionaries