Recursively Mapping ExpandoObject

Question

In my application i have to use ExpandoObject in order to create/delete properties during the runtime; However, i have to map the returned ExpandoObject of a function to the

Answer 1

3- If the property is formated like this public string Property; the get properties does not get it.

Oh, that's not a property, that's a field. If you want consider fields as well.

static Mapper()
{
    PropertyMap = typeof(T).GetProperties(BindingFlags.Public |
                                              BindingFlags.NonPublic |
                                              BindingFlags.Instance)
                                              .ToDictionary(p => p.Name.ToLower(), p => p);

    FieldMap = typeof(T).GetFields(BindingFlags.Public |
                                                BindingFlags.NonPublic |
                                                BindingFlags.Instance)
                                                .ToDictionary(f => f.Name.ToLower(), f => f);
}

2- When i try to map int to a Nullable simply it will throw a type mismatch because i can't find a way to detect and cast it properly.

Why check for Nullable type, let reflection figure it out. If value is valid, it will be assigned.

public static void Map(ExpandoObject source, T destination)
{
    if (source == null)
        throw new ArgumentNullException("source");
    if (destination == null)
        throw new ArgumentNullException("destination");

    foreach (var kv in source)
    {
        PropertyInfo p;
        if (PropertyMap.TryGetValue(kv.Key.ToLower(), out p))
        {
            p.SetValue(destination, kv.Value, null);
        }
        else
        {
            FieldInfo f;
            if (FieldMap.TryGetValue(kv.Key.ToLower(), out f))
            {
                f.SetValue(destination, kv.Value);
            }
        }
    }
}

1 - It does not recursively map the inner objects of the ExpandoObject as supposed.

Seems to work for your InnerClass at least.

Class c = new Class();
dynamic o = new ExpandoObject();
o.Name = "Carl";
o.Level = 7;
o.Inner = new InnerClass
{
    Name = "Inner Carl",
    Level = 10
};

o.Property = "my Property value"; // dont forget to set this

Mapper<Class>.Map(o, c);

EDIT: based on your comments, I've create two overloaded methods MergeProperty. You can write similarly overloaded methods for fields.

public static void MergeProperty(PropertyInfo pi, ExpandoObject source, object target)
{
    Type propType = pi.PropertyType;

    // dont recurse for value type, Nullable<T> and strings
    if (propType.IsValueType || propType == typeof(string))
    {
        var sourceVal = source.First(kvp => kvp.Key == pi.Name).Value;
        if(sourceVal != null)
            pi.SetValue(target, sourceVal, null);
    }
    else // recursively map inner class properties
    {
        var props = propType.GetProperties(BindingFlags.Public |
                                                  BindingFlags.NonPublic |
                                                  BindingFlags.Instance);

        foreach (var p in props)
        {
            var sourcePropValue = source.First(kvp => kvp.Key == pi.Name).Value;
            var targetPropValue = pi.GetValue(target, null);

            if (sourcePropValue != null)
            {
                if (targetPropValue == null) // replace
                {
                    pi.SetValue(target, source.First(kvp => kvp.Key == pi.Name).Value, null);
                }
                else
                {
                    MergeProperty(p, sourcePropValue, targetPropValue);
                }
            }
        }

    }
}

public static void MergeProperty(PropertyInfo pi, object source, object target)
{
    Type propType = pi.PropertyType;
    PropertyInfo sourcePi = source.GetType().GetProperty(pi.Name);

    // dont recurse for value type, Nullable<T> and strings
    if (propType.IsValueType || propType == typeof(string)) 
    {
        var sourceVal = sourcePi.GetValue(source, null);
        if(sourceVal != null)
            pi.SetValue(target, sourceVal, null);
    }
    else // recursively map inner class properties
    {
        var props = propType.GetProperties(BindingFlags.Public |
                                                  BindingFlags.NonPublic |
                                                  BindingFlags.Instance);

        foreach (var p in props)
        {
            var sourcePropValue = sourcePi.GetValue(source, null);
            var targetPropValue = pi.GetValue(target, null);

            if (sourcePropValue != null)
            {
                if (targetPropValue == null) // replace
                {
                    pi.SetValue(target, sourcePi.GetValue(source, null), null);
                }
                else
                {
                    MergeProperty(p, sourcePropValue, targetPropValue);
                }
            }
        }

    }
}

You can use the methods this way:

public static void Map(ExpandoObject source, T destination)
{
    if (source == null)
        throw new ArgumentNullException("source");
    if (destination == null)
        throw new ArgumentNullException("destination");

    foreach (var kv in source)
    {
        PropertyInfo p;
        if (PropertyMap.TryGetValue(kv.Key.ToLower(), out p))
        {
            MergeProperty(p, source, destination);
        }
        else
        {
            // do similar merge for fields
        }
    }
}