Slapper & Dapper Dictionary Support

Question

Slapper & Dapper Dictionary Support

.net automapper c# dapper slapper.automapper

Question

I am trying to map Dapper Data to an Object. But am facing problem while mapping to Dictionary objects.

The Requirement is to map a Data Row to an Object.

Data Row

1 | Key1 | Value1

1 | Key2 | Value2

Expected Values

Id -> 1

Data -{{"Key1","Value1" }, { "Key2","Value2"}}

Map Code:

        IDictionary<string, object> entity = new Dictionary<string, object>();
        entity.Add("Id", "1");
        entity.Add("Data_Key", new List<string>() { "Key1", "Key2" });
        entity.Add("Data_Value", new List<string>() { "Value1", "Value2" });
        var result=Slapper.AutoMapper.Map<TestEntity>(entity);

Entity Object

public class TestEntity
{
    public int Id { get; set; }
    public Dictionary<string,string> Data { get; set; }
}

Is there a way to achieve this ??

Naresh Kumar

View more on Stack Overflow

Naresh Kumar · Accepted Answer · 5/2/2017 1:25:36 PM

As the other user mentioned, it is impossible to achieve it through Slapper.Automapper.

But, I've found a workaround to achieve it.

I have created a TypeConverter, which accepts a JSON String and returns a Dictionary Object.

public class DictionaryConverter : ITypeConverter
{
    public int Order => 110;

    public bool CanConvert(object value, Type type)
    {
        // Handle Nullable types
        var conversionType = Nullable.GetUnderlyingType(type) ?? type;
        //Check if Type is a Dictionary
        return conversionType.IsGenericType && conversionType.GetGenericTypeDefinition() == typeof(Dictionary<,>);
    }

    public object Convert(object value, Type type)
    {
        // Handle Nullable types
        var conversionType = Nullable.GetUnderlyingType(type) ?? type;
        //Create Empty Instance
        object result = Activator.CreateInstance(type);
        if (value != null)
        {
            try
            {
                result = JsonConvert.DeserializeObject(value as string, type);
            }
            catch (JsonException ex)
            {
                throw new Exception("Invalid JSON String while Converting to Dictionary Object", ex);
            }
        }
        return result;
    }
}

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