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Property Handler (Property Level))

This page contains the recommended way of implementing a property handler for the class properties.


Create a class that implements the IPropertyHandler interface.

public class PersonAgePropertyHandler : IPropertyHandler<int?, string>
    public string Get(int? input, ClassProperty property)
        return input.HasValue ? $"{input.Value} years old" : "N/A";

    public int? Set(string input, ClassProperty property)
        return !string.IsNullOrEmpty(input) ? $"{Regex.Replace(key, "[^0-9]", string.Empty)}" : null;

Use the Newtonsoft.Json package if you are using JSON conversion.

public class PersonAddressPropertyHandler : IPropertyHandler<string, Address>
    public Address Get(string input, ClassProperty property)
        return !string.IsNullOrEmpty(input) ? JsonConvert.Deserialize<Address>(input) : null;

    public string Set(Address input, ClassProperty property)
        return input != null ? JsonConvert.Serialize(input) : null;



Use the PropertyHandler attribute to map the property handlers into the class properties.

public class Person
    public int Id { get; set; }

    public string Name { get; set; }

    public string Age { get; set; }

    public DateTime DateOfBirth { get; set; }

    [Map("Address"), PropertyHandler(typeof(PersonAddressPropertyHandler))]
    public Address Location { get; set; }

    public DateTime CreatedDate { get; set; }


Use the FluentMapper class to map the property handlers into the class properties.

    .PropertyHandler<PersonAgePropertyHandler>(e => e.Age)
    .Column(e => e.Location, "Address")
    .PropertyHandler<PersonAddressPropertyHandler>(e => e.Location);

Key Take-aways

  • Ensure to make the TInput generic type nullable if the database column is nullable.
  • Make the code snippets to both Get() and Set() methods concise and highly performant.
  • Name the property handlers as correspond into its own purpose.
  • Mishandling of the implementation would make your application suffer in performance.