CODEWITHSUNDEEP
c#conditional-statementsautomapper
bflemi3
bflemi3

Reputation: 6790

Dynamically mapping with Automapper

I'm trying to conditionally map two objects based on ExtendedField.type. So if the type is textbox then I would map to the TextBox class, but if it's checkbox then I would map to Checkbox class. And of course this needs to be open for extension to map to other IHtmlElement derived types.

Mapper.Map<IEnumerable<ExtendedField, IEnumerable<IHtmlElement>>(extendedFields);

A sample of the objects:

public class ExtendedField {
    public string type { get; set; }
    public string prompt { get; set; }
    public string value { get; set; }
}

public Interface IHtmlElement {
    string label { get; set; }
    string type { get; set; }
    string value { get; set; }
}

public class TextBox : IHtmlElement {
    public string label { get; set; }
    public string type { get { return "textbox"; } }
    public string value { get; set; }
}

public class CheckBox : IHtmlElement {
    public string label { get; set; }
    public string type { get { return "checkbox"; } }
    public string value { get; set; }
}

I have created the mapping to map to IHtmlElement but I can't think of how to dynamically tell AutoMapper which concrete class to map to based off the type property.

Mapper.CreateMap<ExtendedField, IHtmlElement>()
      .ForMember(dest => dest.label, opt => opt.MapFrom(src => src.prompt))
      .ForMember(dest => dest.type, opt => opt.MapFrom(src => src.type))
      .ForMember(dest => dest.value, opt => opt.MapFrom(src => src.extendedFieldValue));

Upvotes: 0

Views: 1194

Answers (1)

alxndr
alxndr

Reputation: 106

in ExtendedField.type you must contain full qualified type name. write type converter:

public class ExtFieldToIHtmlElementConverter : TypeConverter<ExtendedField, IHtmlElement>
    {
        protected override IHtmlElement ConvertCore(ExtendedField source)
        {
            var obj = Activator.CreateInstance(Type.GetType(source.type)) as IHtmlElement;
            obj.label = source.prompt;
            obj.value = source.value;

            return obj;
        }
    }

mapping:

mapper.CreateMap<ExtendedField, IHtmlElement>().ConvertUsing<ExtFieldToIHtmlElementConverter>();

example of using:

var element = Mapper.Map<IHtmlElement>(extFieldObj); // become instance that implement IHtmlElement interface.

Upvotes: 2

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