Useful extension methods for strongly typed access to CRM Entites

CrmEntityExtensions.cs

public static class CrmEntityExtensions
    {
        public static OptionSetValue ToOptionSetValue(this Enum e)
        {
            if (e.GetTypeCode() != TypeCode.Int32)
                return null;

            var val = (int)Convert.ChangeType(e, e.GetTypeCode());

            return new OptionSetValue(val);
        }

        public static void Copy<T>(this Entity entity, params KeyValuePair<Expression<Func<T, object>>, object>[] values)
        {
            foreach (var expression in values)
            {
                SetOrAddAttributeValue(entity, expression.Key, expression.Value);
            }

        }

        public static K GetAttributeValue<T, K>(this Entity entity, Expression<Func<T, object>> attributeLogicalName)
        {
            var column = GetPropertyName(attributeLogicalName).ToLowerInvariant();

            if (!entity.Attributes.ContainsKey(column))
                return default(K);

            return (K)entity.Attributes[column];
        }

        public static void SetOrAddAttributeValue<T>(this Entity entity, Expression<Func<T, object>> attributeLogicalName, object value)
        {
            var column = GetPropertyName<T>(attributeLogicalName).ToLowerInvariant();

            if (!entity.Attributes.ContainsKey(column))
            {
                entity.Attributes.Add(column, value);
            }
            else
            {
                entity.Attributes[column] = value;
            }

        }

        public static void AddCondition<T>(this FilterExpression filter, Expression<Func<T, object>> exp, ConditionOperator conditionOperator, params object[] values)
        {
            var column = GetPropertyName<T>(exp).ToLowerInvariant();

            filter.AddCondition(column, conditionOperator, values);
        }

        public static void AddColumns<T>(this ColumnSet columnSet, params Expression<Func<T, object>>[] exp)
        {
            foreach (var expression in exp)
            {
                var column = GetPropertyName<T>(expression).ToLowerInvariant();

                columnSet.AddColumn(column);
            }
        }

        public static string GetPropertyName<T>(System.Linq.Expressions.Expression<Func<T, object>> property)
        {
            System.Linq.Expressions.LambdaExpression lambda = property;
            System.Linq.Expressions.MemberExpression memberExpression;

            if (lambda.Body is System.Linq.Expressions.UnaryExpression)
            {
                System.Linq.Expressions.UnaryExpression unaryExpression = (System.Linq.Expressions.UnaryExpression)(lambda.Body);
                memberExpression = (System.Linq.Expressions.MemberExpression)(unaryExpression.Operand);
            }
            else
            {
                memberExpression = (System.Linq.Expressions.MemberExpression)(lambda.Body);
            }

            return ((PropertyInfo)memberExpression.Member).Name;
        }
    }