public static Action <TEntity, TField> CreateFieldSetter <TEntity, TField>(Expression <Func <TEntity, TField> > field)
{
// only simple properties are supported
if (!(field.Body is MemberExpression))
{
throw new Exception(
$"Only simple properties are supported; the body of '{field}' is not a MemberExpression.");
}
var simplePropertyNameAggregator = new SimplePropertyNameAggregator();
simplePropertyNameAggregator.Visit(field.Body, false);
// basically we are construction an action "(entity, value) => entity.SomeProperty = value"
var entityParam = Expression.Parameter(typeof(TEntity), "entity");
var inputParam = Expression.Parameter(typeof(TField), "value");
var memberExpression = simplePropertyNameAggregator.PropertyMetaData.PropertyInfoList
.Select(z => z.Name).Reverse().Aggregate <string, Expression>(entityParam, Expression.PropertyOrField);
var binaryExpression = Expression.Assign(memberExpression, inputParam);
var lambda = Expression.Lambda <Action <TEntity, TField> >(binaryExpression, entityParam, inputParam);
var setter = lambda.Compile();
return(setter);
}
public KeyValuePair <string, string> Stringify(TSourceEntity source, TTargetEntity target)
{
Apply(source, target);
var targetFieldString = stringify(targetFieldFunc(target));
var simplePropertyNameAggregator = new SimplePropertyNameAggregator();
simplePropertyNameAggregator.Visit(targetField.Body, false);
if (string.IsNullOrEmpty(tagVlaue))
{
var error =
$"Can't stringify a field where tag value is not defined for source entity: {typeof(TSourceEntity).Name}, " +
$"target entity: {typeof(TTargetEntity).Name}";
throw new Exception(error);
}
var keyFormat = tagVlaue + ".{0}";
var result = new KeyValuePair <string, string>(
string.Format(keyFormat, simplePropertyNameAggregator.PropertyMetaData.PropertyInfoList[0].Name),
targetFieldString);
return(result);
}
