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set nested properties of object while mapping

I am using an expression tree as an alternative to automapper to map source properties to target properties using below code
What i am doing is, I have created static method inside static class for mapping and assigning inner child object property to outer object property
public static class PropertyMapper<TSource, TDest>
{
private static Expression<Func<TSource, Dictionary<string, MasterSection>, TDest>> _mappingExpression;
private static Func<TSource, Dictionary<string, MasterSection>, TDest> _mapper;
static PropertyMapper()
{
_mappingExpression = ProjectionMap();
_mapper = _mappingExpression.Compile();
}
public static Func<TSource, Dictionary<string, MasterSection>, TDest> Mapper => _mapper;
public static Expression<Func<TSource, Dictionary<string, MasterSection>, TDest>> ProjectionMap()
{
var sourceProperties = typeof(TSource).GetProperties().Where(p => p.CanRead);
var targetProperties= typeof(TDest).GetProperties().Where(p => p.CanWrite);
var propertyMap =
from d in targetProperties
join s in sourceProperties on new { d.Name, d.PropertyType } equals new { s.Name, s.PropertyType }
where d.Name != "SourceOfDataId" && d.Name!= "SourceOfData"
select new { Source = s, Dest = d };
var itemParam = Expression.Parameter(typeof(TSource), "item");
var memberBindings = propertyMap.Select(p => (MemberBinding)Expression.Bind(p.Dest, Expression.Property(itemParam, p.Source))).ToList();
var sourceOfDataIdProp = targetProperties.FirstOrDefault(s => s.Name == "SourceOfDataId");
if (sourceOfDataIdProp != null)
{
memberBindings.Add(Expression.Bind(sourceOfDataIdProp,Expression.Convert(Expression.Property(Expression.Property(itemParam, "SourceOfData"),"Id"),typeof(Guid?))));
}
var sourceOfDataProp = targetProperties.FirstOrDefault(s => s.Name == "SourceOfData");
if(sourceOfDataProp != null)
{
// here i would like to update `sourceOfData` object property "isApproved"
}
var newExpression = Expression.New(typeof(TDest));
var memberInitExpression = Expression.MemberInit(newExpression, memberBindings);
var projection = Expression.Lambda<Func<TSource, Dictionary<string, MasterSection>, TDest>>(memberInitExpression, itemParam, dictParam);
return projection;
}
}
and i am using the above method here in below to map the source properties to target properties
AirflowsLab = sourceMechanicalData.AirflowsLab.Select(a => PropertyMapper<LibraryLabAirflow, LibraryLabAirflow>.Mapper(a, masterSectionMappedLibrary)).ToList();
and the structure for LibraryLabAirflow is looks like as below
public class LibraryLabAirflow
{
[ForeignKey("SourceOfData")]
public Guid? SourceOfDataId { get; set; }
public virtual CodeStandardGuideline SourceOfData { get; set; }
}
Above mapping is working fine, what i am trying is now that i need to access the sourceOfData child object of target and update the property for sourceOfData and map that updated child object to source child object sourceOfData.
below is the sourceOfData object details
"SourceOfData":{
"Id": "c5bf3585-50b1-4894-8fad-0ac884343935",
"IsApproved": null, // trying to set this to true instead of null inside target object
"MasterSection": null
},
I am not sure how to access the child object property using an expression tree in this scenario and i cannot use automapper library. Could any one please let me know how to access the child object property and update and assign back to target.
What i am trying to generate an expression looks like this source.SourceOfData = target.SourceOfData but before this i need to update one of the property of target.SourceOfData
Many thanks in advance
Desired expression :
AirflowsLab = sourceMechanicalData.AirflowsLab.Where(a => a != null).Select(item => new LibraryLabAirflow()
{
SourceOfData = new CodeStandardGuideline()
{
IsApproved = true,// trying to set this through expression tree
City = item.SourceOfData.City
......
.......
}
}).ToList(),
trying like this is not working as well, 1
var sourceOfDataProp = targetProperties.FirstOrDefault(s => s.Name == "SourceOfData");
if(sourceOfDataProp != null)
{
// here need to get the sourceofdata properties
var sourceOfDataProperty = Expression.Property(Expression.Constant(sourceOfDataProp), "IsApproved");
}
Update:
i have implemented the logic inside if block of sourceOfDataProp != null but getting an error
if (sourceOfDataProp != null)
{
var targetitemParam = Expression.Parameter(typeof(TTarget), "item");
var sourceOfDataPropertiesFilter = new List<string>()
{
"IsApproved"
};
var sourceItem = Expression.Property(itemParam, typeof(TSource).GetProperty("SourceOfData"));
var sourcePropertyInfo = sourceItem.Type.GetProperties().Where(p => p.CanRead);
var targetItem = Expression.Property(targetitemParam, typeof(TTarget).GetProperty("SourceOfData"));
var targetPropertyInfo = targetItem.Type.GetProperties().Where(p => p.CanWrite);
var sourceOfDataPropertyMap = from tp in targetPropertyInfo
join sp in sourcePropertyInfo
on new { tp.Name, tp.PropertyType } equals new { sp.Name, sp.PropertyType }
where !sourceOfDataPropertiesFilter.Contains(tp.Name)
select new { Source = sp, Target = tp };
// getting error at below line type of arguments does not match
var sourceOfDataMemberBindings = sourceOfDataPropertyMap.Select(p => Expression.Bind(p.Target, Expression.PropertyOrField(targetitemParam, "SourceOfData"))).ToList();
}

I have solved this problem like as below
if (sourceOfDataProp != null)
{
var targetItemParam = Expression.Parameter(typeof(TTarget), "item");
var sourceOfDataPropertiesFilter = new List<string>()
{
"IsApproved"
};
var sourceItem = Expression.Property(itemParam, typeof(TSource).GetProperty("SourceOfData"));
var sourceOfDataSourceProperties = sourceItem.Type.GetProperties().Where(p => p.CanRead);
var targetItem = Expression.Property(targetItemParam, typeof(TTarget).GetProperty("SourceOfData"));
var sourceOfDataTargetProperties = targetItem.Type.GetProperties().Where(p => p.CanWrite);
var sourceOfDataPropertyMap = sourceOfDataTargetProperties.Join(sourceOfDataSourceProperties,
t => new { t.Name, t.PropertyType },
s => new { s.Name, s.PropertyType },
(t, s) => new { Source = s, Target = t })
.Where(t => !sourceOfDataPropertiesFilter.Contains(t.Target.Name));
var sourceOfDataMemberBindings = sourceOfDataPropertyMap.Select(p => Expression.Bind(p.Target, Expression.Property(sourceItem, p.Source))).ToList();
var sourceOfDataIsApprovedProp = sourceOfDataTargetProperties.FirstOrDefault(s => s.Name == "IsApproved");
if (sourceOfDataIsApprovedProp != null)
{
sourceOfDataMemberBindings.Add(Expression.Bind(sourceOfDataIsApprovedProp, Expression.Constant(true, typeof(bool?))));
}
var sourceOfDataExpression = Expression.New(typeof(DesignHub.Entities.CodeStandardGuideline));
var sourceOfDataMemberInitExpression = Expression.MemberInit(sourceOfDataExpression, sourceOfDataMemberBindings);
memberBindings.Add(Expression.Bind(sourceOfDataProp, sourceOfDataMemberInitExpression));
}

Convert from Object to QueryString [duplicate]

How do I serialize an object into query-string format? I can't seem to find an answer on google. Thanks.
Here is the object I will serialize as an example.
public class EditListItemActionModel
{
public int? Id { get; set; }
public int State { get; set; }
public string Prefix { get; set; }
public string Index { get; set; }
public int? ParentID { get; set; }
}

I'm 99% sure there's no built-in utility method for this. It's not a very common task, since a web server doesn't typically respond with a URLEncoded key/value string.
How do you feel about mixing reflection and LINQ? This works:
var foo = new EditListItemActionModel() {
Id = 1,
State = 26,
Prefix = "f",
Index = "oo",
ParentID = null
};
var properties = from p in foo.GetType().GetProperties()
where p.GetValue(foo, null) != null
select p.Name + "=" + HttpUtility.UrlEncode(p.GetValue(foo, null).ToString());
// queryString will be set to "Id=1&State=26&Prefix=f&Index=oo"
string queryString = String.Join("&", properties.ToArray());
Update:
To write a method that returns the QueryString representation of any 1-deep object, you could do this:
public string GetQueryString(object obj) {
var properties = from p in obj.GetType().GetProperties()
where p.GetValue(obj, null) != null
select p.Name + "=" + HttpUtility.UrlEncode(p.GetValue(obj, null).ToString());
return String.Join("&", properties.ToArray());
}
// Usage:
string queryString = GetQueryString(foo);
You could also make it an extension method without much additional work
public static class ExtensionMethods {
public static string GetQueryString(this object obj) {
var properties = from p in obj.GetType().GetProperties()
where p.GetValue(obj, null) != null
select p.Name + "=" + HttpUtility.UrlEncode(p.GetValue(obj, null).ToString());
return String.Join("&", properties.ToArray());
}
}
// Usage:
string queryString = foo.GetQueryString();

Using Json.Net it would be much easier, by serializing and then deserializing to key value pairs.
Here is a code example:
using Newtonsoft.Json;
using System.Web;
string ObjToQueryString(object obj)
{
var step1 = JsonConvert.SerializeObject(obj);
var step2 = JsonConvert.DeserializeObject<IDictionary<string, string>>(step1);
var step3 = step2.Select(x => HttpUtility.UrlEncode(x.Key) + "=" + HttpUtility.UrlEncode(x.Value));
return string.Join("&", step3);
}

Building on the good ideas from other comments, I have made a generic extension method .ToQueryString(), which can be used on any object.
public static class UrlHelpers
{
public static string ToQueryString(this object request, string separator = ",")
{
if (request == null)
throw new ArgumentNullException("request");
// Get all properties on the object
var properties = request.GetType().GetProperties()
.Where(x => x.CanRead)
.Where(x => x.GetValue(request, null) != null)
.ToDictionary(x => x.Name, x => x.GetValue(request, null));
// Get names for all IEnumerable properties (excl. string)
var propertyNames = properties
.Where(x => !(x.Value is string) && x.Value is IEnumerable)
.Select(x => x.Key)
.ToList();
// Concat all IEnumerable properties into a comma separated string
foreach (var key in propertyNames)
{
var valueType = properties[key].GetType();
var valueElemType = valueType.IsGenericType
? valueType.GetGenericArguments()[0]
: valueType.GetElementType();
if (valueElemType.IsPrimitive || valueElemType == typeof (string))
{
var enumerable = properties[key] as IEnumerable;
properties[key] = string.Join(separator, enumerable.Cast<object>());
}
}
// Concat all key/value pairs into a string separated by ampersand
return string.Join("&", properties
.Select(x => string.Concat(
Uri.EscapeDataString(x.Key), "=",
Uri.EscapeDataString(x.Value.ToString()))));
}
}
It will also work for objects that have properties of the type Array and generic Lists if they only contain primitives or strings.
Try it out, comments are welcome: Serialize object into a query string with Reflection

Based on the the popular answers, I needed to update the code to support arrays as well. Sharing the implementation:
public string GetQueryString(object obj)
{
var result = new List<string>();
var props = obj.GetType().GetProperties().Where(p => p.GetValue(obj, null) != null);
foreach (var p in props)
{
var value = p.GetValue(obj, null);
var enumerable = value as ICollection;
if (enumerable != null)
{
result.AddRange(from object v in enumerable select string.Format("{0}={1}", p.Name, HttpUtility.UrlEncode(v.ToString())));
}
else
{
result.Add(string.Format("{0}={1}", p.Name, HttpUtility.UrlEncode(value.ToString())));
}
}
return string.Join("&", result.ToArray());
}

It will also be useful for nested objects
public static class HttpQueryStrings
{
private static readonly StringBuilder _query = new();
public static string ToQueryString<T>(this T #this) where T : class
{
_query.Clear();
BuildQueryString(#this, "");
if (_query.Length > 0) _query[0] = '?';
return _query.ToString();
}
private static void BuildQueryString<T>(T? obj, string prefix = "") where T : class
{
if (obj == null) return;
foreach (var p in obj.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance))
{
if (p.GetValue(obj, Array.Empty<object>()) != null)
{
var value = p.GetValue(obj, Array.Empty<object>());
if (p.PropertyType.IsArray && value?.GetType() == typeof(DateTime[]))
foreach (var item in (DateTime[])value)
_query.Append($"&{prefix}{p.Name}={item.ToString("yyyy-MM-dd")}");
else if (p.PropertyType.IsArray)
foreach (var item in (Array)value!)
_query.Append($"&{prefix}{p.Name}={item}");
else if (p.PropertyType == typeof(string))
_query.Append($"&{prefix}{p.Name}={value}");
else if (p.PropertyType == typeof(DateTime) && !value!.Equals(Activator.CreateInstance(p.PropertyType))) // is not default
_query.Append($"&{prefix}{p.Name}={((DateTime)value).ToString("yyyy-MM-dd")}");
else if (p.PropertyType.IsValueType && !value!.Equals(Activator.CreateInstance(p.PropertyType))) // is not default
_query.Append($"&{prefix}{p.Name}={value}");
else if (p.PropertyType.IsClass)
BuildQueryString(value, $"{prefix}{p.Name}.");
}
}
}
}
An example of using the solution:
string queryString = new
{
date = new DateTime(2020, 1, 1),
myClass = new MyClass
{
FirstName = "john",
LastName = "doe"
},
myArray = new int[] { 1, 2, 3, 4 },
}.ToQueryString();

Perhaps this Generic approach will be useful:
public static string ConvertToQueryString<T>(T entity) where T: class
{
var props = typeof(T).GetProperties();
return $"?{string.Join('&', props.Where(r=> r.GetValue(entity) != null).Select(r => $"{HttpUtility.UrlEncode(r.Name)}={HttpUtility.UrlEncode(r.GetValue(entity).ToString())}"))}";
}

public static class UrlHelper
{
public static string ToUrl(this Object instance)
{
var urlBuilder = new StringBuilder();
var properties = instance.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public);
for (int i = 0; i < properties.Length; i++)
{
urlBuilder.AppendFormat("{0}={1}&", properties[i].Name, properties[i].GetValue(instance, null));
}
if (urlBuilder.Length > 1)
{
urlBuilder.Remove(urlBuilder.Length - 1, 1);
}
return urlBuilder.ToString();
}
}

This my solution:
public static class ObjectExtensions
{
public static string ToQueryString(this object obj)
{
if (!obj.GetType().IsComplex())
{
return obj.ToString();
}
var values = obj
.GetType()
.GetProperties()
.Where(o => o.GetValue(obj, null) != null);
var result = new QueryString();
foreach (var value in values)
{
if (!typeof(string).IsAssignableFrom(value.PropertyType)
&& typeof(IEnumerable).IsAssignableFrom(value.PropertyType))
{
var items = value.GetValue(obj) as IList;
if (items.Count > 0)
{
for (int i = 0; i < items.Count; i++)
{
result = result.Add(value.Name, ToQueryString(items[i]));
}
}
}
else if (value.PropertyType.IsComplex())
{
result = result.Add(value.Name, ToQueryString(value));
}
else
{
result = result.Add(value.Name, value.GetValue(obj).ToString());
}
}
return result.Value;
}
private static bool IsComplex(this Type type)
{
var typeInfo = type.GetTypeInfo();
if (typeInfo.IsGenericType && typeInfo.GetGenericTypeDefinition() == typeof(Nullable<>))
{
// nullable type, check if the nested type is simple.
return IsComplex(typeInfo.GetGenericArguments()[0]);
}
return !(typeInfo.IsPrimitive
|| typeInfo.IsEnum
|| type.Equals(typeof(Guid))
|| type.Equals(typeof(string))
|| type.Equals(typeof(decimal)));
}
}
I use this extension for my integration test, it works perfectly :)

Just another variation of the above, but I wanted to utilize the existing DataMember attributes in my model class, so only the properties I want to serialize are sent to the server in the url in the GET request.
public string ToQueryString(object obj)
{
if (obj == null) return "";
return "?" + string.Join("&", obj.GetType()
.GetProperties()
.Where(p => Attribute.IsDefined(p, typeof(DataMemberAttribute)) && p.GetValue(obj, null) != null)
.Select(p => $"{p.Name}={Uri.EscapeDataString(p.GetValue(obj).ToString())}"));
}

Here is something I wrote that does what you need.
public string CreateAsQueryString(PageVariables pv) //Pass in your EditListItemActionModel instead
{
int i = 0;
StringBuilder sb = new StringBuilder();
foreach (var prop in typeof(PageVariables).GetProperties())
{
if (i != 0)
{
sb.Append("&");
}
var x = prop.GetValue(pv, null).ToString();
if (x != null)
{
sb.Append(prop.Name);
sb.Append("=");
sb.Append(x.ToString());
}
i++;
}
Formating encoding = new Formating();
// I am encoding my query string - but you don''t have to
return "?" + HttpUtility.UrlEncode(encoding.RC2Encrypt(sb.ToString()));
}

I was looking for a solution to this for a Windows 10 (UWP) App. Taking the Relection approach suggested by Dave, and after adding the Microsoft.AspNet.WebApi.Client Nuget package, I used the following code,
which handles Url Encoding of the property values:
private void AddContentAsQueryString(ref Uri uri, object content)
{
if ((uri != null) && (content != null))
{
UriBuilder builder = new UriBuilder(uri);
HttpValueCollection query = uri.ParseQueryString();
IEnumerable<PropertyInfo> propInfos = content.GetType().GetRuntimeProperties();
foreach (var propInfo in propInfos)
{
object value = propInfo.GetValue(content, null);
query.Add(propInfo.Name, String.Format("{0}", value));
}
builder.Query = query.ToString();
uri = builder.Uri;
}
}

A simple approach that supports list properties:
public static class UriBuilderExtensions
{
public static UriBuilder SetQuery<T>(this UriBuilder builder, T parameters)
{
var fragments = typeof(T).GetProperties()
.Where(property => property.CanRead)
.Select(property => new
{
property.Name,
Value = property.GetMethod.Invoke(parameters, null)
})
.Select(pair => new
{
pair.Name,
List = (!(pair.Value is string) && pair.Value is IEnumerable list ? list.Cast<object>() : new[] { pair.Value })
.Select(element => element?.ToString())
.Where(element => !string.IsNullOrEmpty(element))
})
.Where(pair => pair.List.Any())
.SelectMany(pair => pair.List.Select(value => Uri.EscapeDataString(pair.Name) + '=' + Uri.EscapeDataString(value)));
builder.Query = string.Join("&", fragments);
return builder;
}
}
A faster solution which is as fast as spelling out the code to serialize each type:
public static class UriBuilderExtensions
{
public static UriBuilder SetQuery<TSource>(this UriBuilder builder, TSource parameters)
{
var fragments = Cache<TSource>.Properties
.Select(property => new
{
property.Name,
List = property.FetchValue(parameters)?.Where(item => !string.IsNullOrEmpty(item))
})
.Where(parameter => parameter.List?.Any() ?? false)
.SelectMany(pair => pair.List.Select(item => Uri.EscapeDataString(pair.Name) + '=' + Uri.EscapeDataString(item)));
builder.Query = string.Join("&", fragments);
return builder;
}
/// <summary>
/// Caches dynamically emitted code which converts a types getter property values to a list of strings.
/// </summary>
/// <typeparam name="TSource">The type of the object being serialized</typeparam>
private static class Cache<TSource>
{
public static readonly IEnumerable<IProperty> Properties =
typeof(TSource).GetProperties()
.Where(propertyInfo => propertyInfo.CanRead)
.Select(propertyInfo =>
{
var source = Expression.Parameter(typeof(TSource));
var getter = Expression.Property(source, propertyInfo);
var cast = Expression.Convert(getter, typeof(object));
var expression = Expression.Lambda<Func<TSource, object>>(cast, source).Compile();
return new Property
{
Name = propertyInfo.Name,
FetchValue = typeof(IEnumerable).IsAssignableFrom(propertyInfo.PropertyType) && propertyInfo.PropertyType != typeof(string) ?
CreateListFetcher(expression) :
CreateValueFetcher(expression)
};
})
.OrderBy(propery => propery.Name)
.ToArray();
/// <summary>
/// Creates a function which serializes a <see cref="IEnumerable"/> property value to a list of strings.
/// </summary>
/// <param name="get">A lambda function which retrieves the property value from a given source object.</param>
private static Func<TSource, IEnumerable<string>> CreateListFetcher(Func<TSource, object> get)
=> obj => ((IEnumerable)get(obj))?.Cast<object>().Select(item => item?.ToString());
/// <summary>
/// Creates a function which serializes a <see cref="object"/> property value to a list of strings.
/// </summary>
/// <param name="get">A lambda function which retrieves the property value from a given source object.</param>
private static Func<TSource, IEnumerable<string>> CreateValueFetcher(Func<TSource, object> get)
=> obj => new[] { get(obj)?.ToString() };
public interface IProperty
{
string Name { get; }
Func<TSource, IEnumerable<string>> FetchValue { get; }
}
private class Property : IProperty
{
public string Name { get; set; }
public Func<TSource, IEnumerable<string>> FetchValue { get; set; }
}
}
}
An example of using either solution:
var url = new UriBuilder("test.com").SetQuerySlow(new
{
Days = new[] { WeekDay.Tuesday, WeekDay.Wednesday },
Time = TimeSpan.FromHours(14.5),
Link = "conferences.com/apple/stream/15",
Pizzas = default(int?)
}).Uri;
Output:
http://test.com/Days=Tuesday&Days=Wednesday&Time=14:30:00&Link=conferences.com%2Fapple%2Fstream%2F15
Neither of the solutions handle exotic types, indexed parameters, or nested parameters.
When manual serialization is simpler, this c#7/.net4.7 approach can help:
public static class QueryParameterExtensions
{
public static UriBuilder SetQuery(this UriBuilder builder, params (string Name, object Obj)[] parameters)
{
var list = parameters
.Select(parameter => new
{
parameter.Name,
Values = SerializeToList(parameter.Obj).Where(value => !string.IsNullOrEmpty(value))
})
.Where(parameter => parameter.Values.Any())
.SelectMany(parameter => parameter.Values.Select(item => Uri.EscapeDataString(parameter.Name) + '=' + Uri.EscapeDataString(item)));
builder.Query = string.Join("&", list);
return builder;
}
private static IEnumerable<string> SerializeToList(object obj)
{
switch (obj)
{
case string text:
yield return text;
break;
case IEnumerable list:
foreach (var item in list)
{
yield return SerializeToValue(item);
}
break;
default:
yield return SerializeToValue(obj);
break;
}
}
private static string SerializeToValue(object obj)
{
switch (obj)
{
case bool flag:
return flag ? "true" : null;
case byte number:
return number == default(byte) ? null : number.ToString();
case short number:
return number == default(short) ? null : number.ToString();
case ushort number:
return number == default(ushort) ? null : number.ToString();
case int number:
return number == default(int) ? null : number.ToString();
case uint number:
return number == default(uint) ? null : number.ToString();
case long number:
return number == default(long) ? null : number.ToString();
case ulong number:
return number == default(ulong) ? null : number.ToString();
case float number:
return number == default(float) ? null : number.ToString();
case double number:
return number == default(double) ? null : number.ToString();
case DateTime date:
return date == default(DateTime) ? null : date.ToString("s");
case TimeSpan span:
return span == default(TimeSpan) ? null : span.ToString();
case Guid guid:
return guid == default(Guid) ? null : guid.ToString();
default:
return obj?.ToString();
}
}
}
Example usage:
var uri = new UriBuilder("test.com")
.SetQuery(("days", standup.Days), ("time", standup.Time), ("link", standup.Link), ("pizzas", standup.Pizzas))
.Uri;
Output:
http://test.com/?days=Tuesday&days=Wednesday&time=14:30:00&link=conferences.com%2Fapple%2Fstream%2F15

In addition to existing answers
public static string ToQueryString<T>(this T input)
{
if (input == null)
{
return string.Empty;
}
var queryStringBuilder = new StringBuilder("?");
var properties = input.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public);
foreach (var property in properties)
{
var value = property.GetValue(input);
if (value is null || property.HasIgnoreDataMember())
continue;
queryStringBuilder.AppendFormat("{0}={1}&", property.GetName(), HttpUtility.UrlEncode(value.ToString()));
}
queryStringBuilder.Length--;
return queryStringBuilder.ToString();
}
private static bool HasIgnoreDataMember(this PropertyInfo propertyInfo)
{
return propertyInfo.GetCustomAttribute(typeof(IgnoreDataMemberAttribute), true) is not null;
}
private static DataMemberAttribute GetDataMemberAttribute(this PropertyInfo propertyInfo)
{
return propertyInfo.GetCustomAttribute<DataMemberAttribute>();
}
private static T GetCustomAttribute<T>(this PropertyInfo propertyInfo) where T : class
{
return propertyInfo.GetCustomAttribute(typeof(T), true) as T;
}
private static string GetName(this PropertyInfo propertyInfo)
{
return propertyInfo.GetDataMemberAttribute()?.Name ?? propertyInfo.Name;
}
}
Usage: var queryString = object.ToQueryString()

Faced with a similar situation what I did, is to XML serialize the object and pass it around as query string parameter.
The difficulty with this approach was that despite encoding, the receiving form throws exception saying "potentially dangerous request...". The way I got around was to encrypt the serialized object and then encode to pass it around as query string parameter. Which in turn made the query string tamper proof (bonus wandering into the HMAC territory)!
FormA XML serializes an object > encrypts the serialized string > encode > pass as query string to FormB
FormB decrypts the query parameter value (as request.querystring decodes also) > deserialize the resulting XML string to object using XmlSerializer.
I can share my VB.NET code upon request to howIdidit-at-applecart-dot-net

Convert this LINQ to dynamic Expression tree

I have an extension in my project that let's me sort an IEnumerable with a string, so that sorting can be done more dynamically.
So, if I have these models:
public MyModel
{
public int Id {get; set;}
public string RecordName {get; set;}
public ChildModel MyChildren {get; set;}
}
public ChildModel
{
public int ChildModelId {get; set;}
public string ChildName {get; set;}
public DateTime SavedDate {get; set;}
}
I could sort my list like this:
var myList = db.MyModel.Where(m => m.IsActive);
myList
.OrderBy(m => m.MyChildren
.OrderByDescending(c => c.SavedDate).FirstOrDefault().SavedDate);
or:
var myList = db.MyModel.Where(m => m.IsActive);
myList.OrderBy(m => m.MyChildren.Max(c => c.SavedDate);
But I want to be able to dynamically sort, based on user options. So I would like this:
var myList = db.MyModel.Where(m => m.IsActive);
myList.OrderByField("MyChildren.SavedDate");
The extension method I have so far looks like this:
public static class MkpExtensions
{
public static IEnumerable<T> OrderByField<T>(this IEnumerable<T> list, string sortExpression)
{
sortExpression += "";
string[] parts = sortExpression.Split(' ');
bool descending = false;
string fullProperty = "";
if (parts.Length > 0 && parts[0] != "")
{
fullProperty = parts[0];
if (parts.Length > 1)
{
descending = parts[1].ToLower().Contains("esc");
}
ParameterExpression inputParameter = Expression.Parameter(typeof(T), "p");
Expression propertyGetter = inputParameter;
foreach (string propertyPart in fullProperty.Split('.'))
{
var checkIfCollection = propertyGetter.Type.GetInterfaces()//(typeof (ICollection<>).FullName);
.Any(x => x.IsGenericType &&
(x.GetGenericTypeDefinition() == typeof(ICollection<>) || x.GetGenericTypeDefinition() == typeof(IEnumerable<>)));
if (checkIfCollection)
{
var pgType = propertyGetter.Type;
var childType = pgType.GetGenericArguments().Single();
var childProp = childType.GetProperty(propertyPart);
ParameterExpression childInParam = Expression.Parameter(childType, "c");
var propertyAccess = Expression.Property(childInParam, childProp);
var orderByExp = Expression.Lambda(propertyAccess, childInParam);
// At this point, orderByExp is c => c.ActionDate
// Now I want to build the expression tree to handle the order by
XXXXX This is where I need help.
}
else
{
// This handles a singular property. Like "MyChildren.ChildName"
// and this part does work
PropertyInfo prop = propertyGetter.Type.GetProperty(propertyPart);
if (prop == null)
throw new Exception("No property '" + fullProperty + "' in + " + propertyGetter.Type.Name + "'");
propertyGetter = Expression.Property(propertyGetter, prop);
}
}
Expression conversion = Expression.Convert(propertyGetter, typeof(object));
var getter = Expression.Lambda<Func<T, object>>(conversion, inputParameter).Compile();
if (descending)
{
// This would be like
// list.OrderByDescending(m => m.MyChildren
// .OrderByDescending(c => c.SavedDate).FirstOrDefault().SavedDate);
return list.OrderByDescending(getter);
}
else
{
// This would be like
// list.OrderBy(m => m.MyChildren
// .OrderByDescending(c => c.SavedDate).FirstOrDefault().SavedDate);
return list.OrderBy(getter);
}
}
return list;
}
}

Basically you should use the following Expression.Call overload which allows you to build an expression for calling static generic methods (what are all the LINQ extension methods).
To build the equivalent of expression like this
m => m.MyChildren.OrderByDescending(c => c.SavedDate).FirstOrDefault().SavedDate
you can use the following snippet:
// At this point, orderByExp is c => c.ActionDate
var orderByDescendingCall = Expression.Call(
typeof(Enumerable), "OrderByDescending", new Type[] { childType, orderByExp.Body.Type },
propertyGetter, orderByExp
);
var firstOrDefaultCall = Expression.Call(
typeof(Enumerable), "FirstOrDefault", new Type[] { childType },
orderByDescendingCall
);
propertyGetter = Expression.Property(firstOrDefaultCall, childProp);
But note that you'll get NRE if the collection is empty.
So you'd better build an expression like this:
m => m.MyChildren.OrderByDescending(c => c.SavedDate)
.Select(c => (DateTime?)c.SavedDate).FirstOrDefault()
with:
// At this point, orderByExp is c => c.ActionDate
var orderByDescendingCall = Expression.Call(
typeof(Enumerable), "OrderByDescending", new Type[] { childType, orderByExp.Body.Type },
propertyGetter, orderByExp
);
Expression propertySelector = propertyAccess;
// If value type property and not nullable, convert it to nullable
if (propertySelector.Type.IsValueType && Nullable.GetUnderlyingType(propertySelector.Type) == null)
propertySelector = Expression.Convert(propertySelector, typeof(Nullable<>).MakeGenericType(propertySelector.Type));
var selectCall = Expression.Call(
typeof(Enumerable), "Select", new Type[] { childType, propertySelector.Type },
orderByDescendingCall, Expression.Lambda(propertySelector, childInParam)
);
propertyGetter = Expression.Call(
typeof(Enumerable), "FirstOrDefault", new Type[] { propertySelector.Type },
selectCall
);

Dynamically build an Expression tree for sorting

I have an extension in my project that let's me sort an IEnumerable with a string, so that sorting can be done more dynamically.
So, if I have these models:
public MyModel
{
public int Id {get; set;}
public string RecordName {get; set;}
public ChildModel MyChild {get; set;}
}
public ChildModel
{
public int ChildModelId {get; set;}
public DateTime SavedDate {get; set;}
}
I can sort two ways:
myList.OrderByField("RecordName ");
myList.OrderByField("MyChild.SavedDate");
However, if my object has an ICollection property, like ICollection<ChildModel> MyChildren I can hard code my sort like this:
myList
.OrderBy(m => m.MyChildren
.OrderByDescending(c => c.SavedDate).FirstOrDefault().SavedDate);
And get what I want.
My question is, how can I update my extension method to allow to get the same results with this:
myList.OrderByField("MyChildren.SavedDate");
Here is my current extension:
public static class MkpExtensions
{
public static IEnumerable<T> OrderByField<T>(this IEnumerable<T> list, string sortExpression)
{
sortExpression += "";
string[] parts = sortExpression.Split(' ');
bool descending = false;
string fullProperty = "";
if (parts.Length > 0 && parts[0] != "")
{
fullProperty = parts[0];
if (parts.Length > 1)
{
descending = parts[1].ToLower().Contains("esc");
}
ParameterExpression inputParameter = Expression.Parameter(typeof(T), "p");
Expression propertyGetter = inputParameter;
foreach (string propertyPart in fullProperty.Split('.'))
{
PropertyInfo prop = propertyGetter.Type.GetProperty(propertyPart);
if (prop == null)
throw new Exception("No property '" + fullProperty + "' in + " + propertyGetter.Type.Name + "'");
propertyGetter = Expression.Property(propertyGetter, prop);
}
Expression conversion = Expression.Convert(propertyGetter, typeof(object));
var getter = Expression.Lambda<Func<T, object>>(conversion, inputParameter).Compile();
if (descending)
return list.OrderByDescending(getter);
else
return list.OrderBy(getter);
}
return list;
}
}
I was thinking of checking the type of the prop and doing an if... else statement, but I'm not sure.
Maybe something like this:
foreach (string propertyPart in fullProperty.Split('.'))
{
var checkIfCollection = propertyGetter.Type.GetInterfaces()//(typeof (ICollection<>).FullName);
.Any(x => x.IsGenericType &&
(x.GetGenericTypeDefinition() == typeof(ICollection<>) || x.GetGenericTypeDefinition() == typeof(IEnumerable<>)));
if (checkIfCollection)
{
// Can I get this to do something like
// myList.OrderBy(m => m.MyChildren.Max(c => c.SavedDate));
// So far, I can get the propertyGetter type, and the type of the elements:
var pgType = propertyGetter.Type;
var childType = pgType.GetGenericArguments().Single();
// Now I want to build the expression tree to get the max
Expression left =
Expression.Call(propertyGetter, pgType.GetMethod("Max", System.Type.EmptyTypes));
// But pgType.GetMethod isn't working
}
else
{
PropertyInfo prop = propertyGetter.Type.GetProperty(propertyPart);
if (prop == null)
throw new Exception("No property '" + fullProperty + "' in + " + propertyGetter.Type.Name + "'");
propertyGetter = Expression.Property(propertyGetter, prop);
}
}

The Max function is an extension method, not a member method of IEnumerable or ICollection. You must call it from it's class Enumerable.
Here is an example of how to call Max through expression tree:
IEnumerable<int> list = new List<int> { 3, 5, 7, 2, 12, 1 };
var type = typeof(Enumerable); //This is the static class that contains Max
//Find The overload of Max that matches the list
var maxMethod = type.GetMethod("Max", new Type[] { typeof(IEnumerable<int>) });
ParameterExpression p = Expression.Parameter(typeof(IEnumerable<int>));
//Max is static, so the calling object is null
var exp = Expression.Call(null, maxMethod, p);
var lambda = Expression.Lambda<Func<IEnumerable<int>, int>>(exp, p);
Console.WriteLine(lambda.Compile()(list));

Matching reference type parameters by Moq setup

I have similar problem to the one asked here or here but the solutions seems not apply in my case.
Consider the following classes:
public interface IProductsWebService
{
ICObjectLang[] GetClassLevel(getClassLevelLang criteria);
}
// the rest of this class was automaticaly generated as web service reference
public partial class getClassLevelLang : IEquatable<getClassLevelLang>
{
public override bool Equals(object obj)
{
var other = obj as getClassLevelLang;
return Equals(other);
}
public bool Equals(getClassLevelLang other)
{
if (this == other)
{
return true;
}
if (other == null)
{
return false;
}
return CID == other.CID &&
accessCode == other.accessCode &&
classCode == other.classCode &&
depth == other.depth &&
language == other.language &&
partyCode == other.partyCode &&
refId == other.refId;
}
public override int GetHashCode()
{
var hash = 531;
hash += CID != null ? CID.GetHashCode() : 1;
hash += accessCode != null ? accessCode.GetHashCode() : 1;
hash += classCode != null ? classCode.GetHashCode() : 1;
hash += depth != null ? depth.GetHashCode() : 1;
hash += language != null ? language.GetHashCode() : 1;
hash += partyCode != null ? partyCode.GetHashCode() : 1;
hash += refId != null ? refId.GetHashCode() : 1;
return hash;
}
public override string ToString()
{
var str = new StringBuilder();
str.AppendFormat("CID: {0}, ", CID);
str.AppendFormat("accessCode: {0}, ", accessCode);
str.AppendFormat("classCode: {0}, ", classCode);
str.AppendFormat("depth: {0}, ", depth);
str.AppendFormat("language: {0}, ", language);
str.AppendFormat("partyCode: {0}, ", partyCode);
str.AppendFormat("refId: {0}", refId);
return str.ToString();
}
}
And the following code for testing (calls list is only for debugging):
private Mock<IProductsWebService> productsService;
private IProductsImportProcess target;
private List<getClassLevelLang> calls = new List<getClassLevelLang>();
[TestMethod]
public void RecursiveDownloadTest()
{
//other mocks (configuration, log, categoryService and configurationService) set here
target = new ProductsImportProcess(
configuration.Object, log.Object, categoryService.Object,
productsService.Object, configurationService.Object);
productsService = new Mock<IProductsWebService>(MockBehavior.Strict);
var root1 = new Category
{
CategoryID = "root1",
SubCategories = new List<Category>
{
new Category
{
CategoryID = "cat1.1",
SubCategories = new List<Category>
{
new Category
{CategoryID = "cat1.1.1"}
}
},
new Category
{
CategoryID = "cat1.2"
}
}
};
var root2 = new Category { CategoryID = "root2" };
setupProductsServiceCall("tree1", root1, true);
setupProductsServiceCall("tree1", root1.SubCategories.First().SubCategories.First());
setupProductsServiceCall("tree2", root2, true);
target.Execute();
productsService.VerifyAll();
}
private void setupProductsServiceCall(string treeCode, Category category, bool isRoot = false)
{
var config = configuration.Object;
var criteria = new getClassLevelLang
{
CID = isRoot ? null : category.CategoryID,
language = "all",
partyCode = "something",
depth = "1",
classCode = treeCode,
accessCode = "xyz"
};
var productsNode = TestUtils.CreateAbbProductsNode(category);
productsService.Setup(mock => mock.GetClassLevel(It.Is<getClassLevelLang>(c => c.Equals(criteria)))).
Callback<getClassLevelLang>(c => calls.Add(c)). //added for debuging purposes only
Returns(productsNode.objectAttributes).
Verifiable();
}
The test above fails with the following exception:
Test method ProductsImport.Console.Test.ProductsImportProcessUnitTest.RecursiveDownloadTest threw exception:
Moq.MockVerificationException: The following setups were not matched:
IProductsWebService mock => mock.GetClassLevel(It.Is<getClassLevelLang>(c => c.Equals(CID: , accessCode: xyz, classCode: tree1, depth: 1, language: all, partyCode: something, refId: )))
IProductsWebService mock => mock.GetClassLevel(It.Is<getClassLevelLang>(c => c.Equals(CID: cat1.1.1, accessCode: xyz, classCode: tree1, depth: 1, language: all, partyCode: something, refId: )))
IProductsWebService mock => mock.GetClassLevel(It.Is<getClassLevelLang>(c => c.Equals(CID: , accessCode: xyz, classCode: tree2, depth: 1, language: all, partyCode: something, refId: )))
Result StackTrace:
at Moq.Mock.VerifyAll()
I'm sure that ProductsWebService.GetClassLevel is being called while getClassLevelLang.Equals is not (checked with debugger). What's more weird I've checked the actual value of calls just before calling VerifyAll() list and it's empty.

Your productsService mock is not getting injected into your ProductsImportProcess so cannot intercept calls made on the actual IProductsWebService. How do you instantiate the IProductsWebService object in your code?