Develop Reference

Extension method to remove not primitive property of an object

I'd like an extension method to create an object based on another but keep only the primitive properties. This object will be dumped into a log file in JSON format for logging.
Based on the classes shown below, in this sample, the created object should keep only these properties :
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
I am using .NET Framework 4.7
How can I do this?
// To use like this
var order = new Order();
var forLog = order.RemovePrimitives();
// Sample of classes
public class Order
{
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
public List<Item> Items { get; set; }
public Address Address { get; set; }
}
public class Item{}
public class Address{}
public static class Extensions
{
public static string RemovePrimitives(this object obj)
{
// I need to create an anonymous, named 'TheNewObjectHere' object but only with primitives
// I will dump the object to push to a log file. I need only primitives
return JsonConvert.SerializeObject(TheNewObjectHere, Formatting.Indented);
}
}
Thanks

try this
public static class Extensions
{
public static string RemovePrimitives(this object obj)
{
var jsonObj = JObject.FromObject(obj);
var propToRemove = jsonObj.Properties().Where(i => !i.Value.GetType().ToString()
.Contains("JValue")).ToList();
foreach (var prop in propToRemove) prop.Remove();
return jsonObj.ToString();
}
}

You can use reflection to get primitive properties and then use JObject to build a JSON object dynamically.
public static readonly Type[] AdditionalPrimities = new[] { typeof(decimal), typeof(string) };
public static string RemovePrimitives<T>(this T obj)
{
var jObj = new JObject();
var props = GetPrimitiveProperties(obj);
foreach (var item in props)
{
var value = item.GetValue(obj);
if (value != null)
{
jObj.Add(item.Name, new JValue(value));
}
}
return jObj.ToString(Newtonsoft.Json.Formatting.Indented);
}
public static PropertyInfo[] GetPrimitiveProperties<T>()
{
var properties = typeof(T)
.GetProperties(BindingFlags.Instance | BindingFlags.Public)
.Where(r => r.PropertyType.IsPrimitive || (r.PropertyType.IsGenericType && Nullable.GetUnderlyingType(r.PropertyType) != null) || AdditionalPrimities.Contains(r.PropertyType))
.Select(r => r)
.ToArray();
return properties;
}
public static void Main()
{
var order = new Order { FirstName = "abc", LastName = "cde", Address = new Address(), Age2 = 3, Age = 1 };
var final = order.RemovePrimitives();
Console.WriteLine(final);
}
Fiddle

c# Loop List<T> row and trim column values

public class Person {
string Name
string Address
int Age
.. 100+ more columns
}
var result = new List<Person>();
foreach (var item in result )
{
//loop column and trim the values.
}
I want the simplest way to loop the columns (assuming 100+ columns) where datatype is string then trim the value.
To rephrase in more C# terms: I want to update all properties and fields of an object that are of type string with trimmed value as item.StringProp = item.StringProp.Trim(). I don't want to manually write update for each property.

You could use reflection and Linq for filtering the properties of type string. From the OP, it looks like you are using Fields instead of properties. Please note it is unclear whether the Properties/Fields are public from OP, if you need to use public fields/properties, please use BindingFlags.Public
public List<T> TrimList<T>(List<T> source)
{
foreach(var property in typeof(T).GetFields(BindingFlags.NonPublic | BindingFlags.Instance).Where(x=>x.FieldType== typeof(string)))
{
foreach(var personItem in source)
property.SetValue(personItem,Convert.ToString(property.GetValue(personItem)).Trim());
}
return source;
}
If properties, you could use
public List<T> TrimList<T>(List<T> source)
{
foreach(var property in typeof(T).GetProperties(BindingFlags.NonPublic | BindingFlags.Instance).Where(x=>x.PropertyType== typeof(string)))
{
foreach(var personItem in source)
property.SetValue(personItem,Convert.ToString(property.GetValue(personItem)).Trim());
}
return source;
}
Demo Code
Note: prior to .NET 4.5 you need to pass null as a second argument:
public List<T> TrimList<T>(List<T> source)
{
foreach(var property in typeof(T).GetProperties(BindingFlags.NonPublic | BindingFlags.Instance).Where(x=>x.PropertyType== typeof(string)))
{
foreach(var personItem in source)
property.SetValue(personItem,Convert.ToString(property.GetValue(personItem,null)).Trim());
}
return source;
}

As well as reflection, another way is to make it the responsibility of the Person class.
public class Person {
public string Name { get; set; }
public string Address { get; set; }
public int Age { get; set; }
.. 100+ more columns
public void DoTrim()
{
this.Name = this.Name.Trim();
this.Address = this.Address.Trim();
... still need to code 100+ properties
}
}
The advantage is that you can call it like this
var result = new List<Person>();
...
for(int i=0; i < result.Count(); i++)
{
result[i].DoTrim();
}
Or you can control your data in the Person class when you set it and use local private variables.
public class Person {
private string name;
public string Name
{
get { return name; }
set { name = value.Trim(); }
}
private string address;
public string Address
{
get { return address; }
set { address= value.Trim(); }
}
....

This is how I would implement it:
class Program
{
static void Main(string[] args)
{
var obj = new Person
{
MyProperty = " A",
MyProperty1 = " A ",
MyProperty2 = "A ",
MyProperty3 = "A A A",
};
TrimStrings(obj);
}
public static void TrimStrings(object obj)
{
Type stringType = typeof(string);
var properties = obj.GetType().GetProperties().Where(x => x.PropertyType == stringType);
foreach(var property in properties)
{
string value = (string)property.GetValue(obj);
property.SetValue(obj, value?.Trim());
}
}
}
public class Person
{
public string MyProperty { get; set; }
public string MyProperty1 { get; set; }
public string MyProperty2 { get; set; }
public string MyProperty3 { get; set; }
}
Output:
{"MyProperty":"A","MyProperty1":"A","MyProperty2":"A","MyProperty3":"A
A A"}

You can use This Nuget Package
.After Install use it as bellow:
result.ForEach(x => x.AdjustString());

c# Reflection - Accessing object properties on static class

I used code from this post to implement feature toggles in an application and it is working great. However, now instead of my features being a straight bool on/off, each feature has two bool values: one for the general setting and one for the setting which is only applied to a subset of users. I've been trying to update the code to handle this and I'm finding my basic understanding of reflection and accessors is coming up short.
I'm using the code below to test in LINQPad - basically, compared to the post mentioned above, all I've done is tried to change TestFeatureToggle from a bool, to type MultiToggle but I'm struggling to Set or Get the value of the bool properties of the MultiToggle object. I get an exception at
return (bool)multiToggleProperty.GetValue(null,null);
"Non-static method requires a target". Which makes sense because the properties on MultiToggle are non-static. However, I don't have an instance of those objects and I don't understand how I would get one from a static class.
Any help would be really appreciated. My gut says it might not be possible!
void Main()
{
var exampleFeatureToggles = new List<FeatureToggle>
{
new FeatureToggle {Description = "Test", Id = 1, IsActive = true, Name = "TestFeatureToggle"}
};
FeatureToggles.SetFeatureToggles(exampleFeatureToggles);
Console.WriteLine(FeatureToggles.GetFeatureToggleSetting("TestFeatureToggle"));
}
public class FeatureToggle
{
public string Description { get; set; }
public int Id { get; set; }
public bool IsActive { get; set; }
public string Name { get; set; }
}
public class MultiToggle
{
public bool DefaultValue { get; private set; }
public bool OtherValue { get; private set; }
}
public static class FeatureToggles
{
//public static bool TestFeatureToggle { get; private set; }
public static MultiToggle TestFeatureToggle { get; private set; }
public static void SetFeatureToggles(List<FeatureToggle> toggles)
{
if (toggles == null) return;
var properties = typeof(FeatureToggles).GetProperties(BindingFlags.Public | BindingFlags.Static);
// All properties must be set to false to prevent a property staying true when deleted from the database
foreach (var property in properties)
{
var multiToggleProperties = typeof(MultiToggle).GetProperties();
foreach (var multiToggleProperty in multiToggleProperties)
{
multiToggleProperty.SetValue(new MultiToggle(), false, null);
}
}
foreach (var toggle in toggles)
{
foreach (var property in properties)
{
if (property.Name.ToLower() == toggle.Name.ToLower())
{
Type tProp = property.GetType();
var multiToggleProperties = typeof(MultiToggle).GetProperties();
foreach (var multiToggleProperty in multiToggleProperties)
{
Console.WriteLine(multiToggleProperty);
multiToggleProperty.SetValue(new MultiToggle(), toggle.IsActive, null);
}
}
}
}
}
public static bool GetFeatureToggleSetting(string propertyName)
{
var properties = typeof(FeatureToggles).GetProperties(BindingFlags.Public | BindingFlags.Static);
foreach (var property in properties)
{
if (property.Name.ToLower() == propertyName.ToLower())
{
Type tProp = property.GetType();
var multiToggleProperties = typeof(MultiToggle).GetProperties();
Console.WriteLine(multiToggleProperties);
foreach (var multiToggleProperty in multiToggleProperties)
{
Console.WriteLine(multiToggleProperty);
return (bool)multiToggleProperty.GetValue(null, null);
}
}
}
return false;
}
}

The idea was there but you've essentially "just overshot the mark". You are getting the "Non-static method requires a target" error because you are trying to get the value of a property in the value of a static property, without getting the value of the static property first (what a mouthful). i.e. you are going:
get static property type -> get instance property type -> get value of property from static property.
DefaultValue, and OtherValue are instance properties so you will need the instance object first before you can get their value. I made a few tweaks just to show you how to both set the static property and get the values from the static property. You should be able to tweak it from there:
void Main()
{
var exampleFeatureToggles = new List<FeatureToggle>
{
new FeatureToggle {Description = "Test", Id = 1, IsActive = true, Name = "TestFeatureToggle"}
};
FeatureToggles.SetFeatureToggles(exampleFeatureToggles);
Console.WriteLine(FeatureToggles.GetFeatureToggleSetting("TestFeatureToggle"));
}
public class FeatureToggle
{
public string Description { get; set; }
public int Id { get; set; }
public bool IsActive { get; set; }
public string Name { get; set; }
}
public class MultiToggle
{
public bool DefaultValue { get; private set; }
public bool OtherValue { get; private set; }
}
public static class FeatureToggles
{
//public static bool TestFeatureToggle { get; private set; }
public static MultiToggle TestFeatureToggle { get; private set; }
public static void SetFeatureToggles(List<FeatureToggle> toggles)
{
if (toggles == null) return;
var properties = typeof(FeatureToggles).GetProperties(BindingFlags.Public | BindingFlags.Static);
// All properties must be set to false to prevent a property staying true when deleted from the database
foreach (var property in properties)
{
// first change: set the _property_, not multiToggleProperty
property.SetValue(null, new MultiToggle());
}
foreach (var toggle in toggles)
{
foreach (var property in properties)
{
if (property.Name.ToLower() == toggle.Name.ToLower())
{
Type tProp = property.GetType();
var multiToggleProperties = typeof(MultiToggle).GetProperties();
// second change: create a nee instance, set the values, then set that value on the static property
var newMultiToggle = new MultiToggle();
property.SetValue(null, newMultiToggle);
foreach (var multiToggleProperty in multiToggleProperties)
{
Console.WriteLine(multiToggleProperty);
multiToggleProperty.SetValue(newMultiToggle, toggle.IsActive, null);
}
}
}
}
}
public static bool GetFeatureToggleSetting(string propertyName)
{
var properties = typeof(FeatureToggles).GetProperties(BindingFlags.Public | BindingFlags.Static | BindingFlags.FlattenHierarchy);
foreach (var property in properties)
{
if (property.Name.ToLower() == propertyName.ToLower())
{
Type tProp = property.GetType();
// third change: get the static value first, then get the value from the properties on that instance.
var value = property.GetValue(null);
var multiToggleProperties = typeof(MultiToggle).GetProperties();
Console.WriteLine(multiToggleProperties);
foreach (var multiToggleProperty in multiToggleProperties)
{
Console.WriteLine(multiToggleProperty);
return (bool)multiToggleProperty.GetValue(value, null); //
}
}
}
return false;
}
}

passing around values to an AutoMapper Type Converter from outside

I have a multilingual database, which returns values based on a key and an enum Language. When I convert a DB object to a model, I want the model to contain the translated value based on the key and the current language.
The key comes from the DB object but how can I pass the current language to the the Mapper.Map() function?
Currently, I am using a [ThreadStatic] attribute to set the culture before calling Mapper.Map<>, and to retrieve it in the TypeConverter.
public enum Language
{
English, French, Italian, Maltese
}
public class MultilingualValue<T>
{
public Dictionary<Language, T> Value { get; set; }
public MultilingualValue()
{
this.Value = new Dictionary<Language, T>();
}
}
public class PersonData
{
public string FirstName { get; set; }
public MultilingualValue<string> City { get; set; }
}
public void MapPerson()
{
PersonData personData = new PersonData();
personData.FirstName = "John";
personData.City = new MultilingualValue<string>();
personData.City.Value[ Language.English] = "The Zurrieq";
personData.City.Value[Language.French] = "Le Zurrieque";
MultilingualValueData.CurrentLanguage = Language.English;
var personModel = Mapper.Map<PersonData, PersonModel>(personData);
}
public class MultilingualValueToBasicDataTypeConverter<T> : ITypeConverter<MultilingualValue<T>, T>
{
public T Convert(ResolutionContext context)
{
var currentLanguage = MultilingualValueData.CurrentLanguage; //THIS IS THE [ThreadStatic] VARIABLE
if (currentLanguage == null) throw new InvalidOperationException("Please make sure to fill in CurrentLanguage");
MultilingualValue<T> sourceMultilingualValue = (MultilingualValue < T > )context.SourceValue;
T destinationValue = default(T);
if (sourceMultilingualValue != null)
{
destinationValue = sourceMultilingualValue.Value[currentLanguage.Value];
}
return destinationValue;
}
}
public static class MultilingualValueData
{
[ThreadStatic]
public static Language? CurrentLanguage;
}
I left out the configurations as I think they're unneccessary for this example. If you need them, I'll post them as well.
While this works, I find this workaround quite ugly. Is there any way to pass data through the ResolutionContext?

Just use the Map overload that takes a Action<IMappingOperationOptions>. You can add configuration elements to the Items property that are then passed to your ITypeConverter
public class CustomConverter : ITypeConverter<string, string>
{
public string Convert(ResolutionContext context)
{
return "translated in " + context.Options.Items["language"];
}
}
internal class Program
{
private static void Main(string[] args)
{
AutoMapper.Mapper.CreateMap<string, string>().ConvertUsing<CustomConverter>();
var result = AutoMapper.Mapper.Map<string, string>("value" , opt => opt.Items["language"] = "english");
Console.Write(result); // prints "translated in english"
Console.ReadLine();
}
}

Remove the null property from object

,I have one class in which I have three properties now what I want to do, if in the object if any one of null or empty then I want to remove it from the object below is my code.
public class TestClass
{
public string Name { get; set; }
public int ID { get; set; }
public DateTime? DateTime { get; set; }
public string Address { get; set; }
}
TestClass t=new TestClass();
t.Address="address";
t.ID=132;
t.Name=string.Empty;
t.DateTime=null;
Now here I want the object of TestClass but in that Name and DateTime property should not be their in the object,
is it possible?
Please help me

There's no such concept as removing a property from an individual object. The type decided which properties are present - not individual objects.
In particular, it will always be valid to have a method like this:
public void ShowDateTime(TestClass t)
{
Console.WriteLine(t.DateTme);
}
That code has no way of knowing whether you've wanted to "remove" the DateTime property from the object that t refers to. If the value is null, it will just get that value - that's fine. But you can't remove the property itself.
If you're listing the properties of an object somewhere, you should do the filtering there, instead.
EDIT: Okay, no you've given us some context:
ok I am using Schemaless database so null and empty value also store space in database that's the reason
So in the code you're using which populates that database, just don't set any fields which corresponds to properties with a null value. That's purely a database population concern - not a matter for the object itself.
(I'd also argue that you should consider how much space you'll really save by doing this. Do you really care that much?)

I was bored and got this in LINQPad
void Main()
{
TestClass t=new TestClass();
t.Address="address";
t.ID=132;
t.Name=string.Empty;
t.DateTime=null;
t.Dump();
var ret = t.FixMeUp();
((object)ret).Dump();
}
public static class ReClasser
{
public static dynamic FixMeUp<T>(this T fixMe)
{
var t = fixMe.GetType();
var returnClass = new ExpandoObject() as IDictionary<string, object>;
foreach(var pr in t.GetProperties())
{
var val = pr.GetValue(fixMe);
if(val is string && string.IsNullOrWhiteSpace(val.ToString()))
{
}
else if(val == null)
{
}
else
{
returnClass.Add(pr.Name, val);
}
}
return returnClass;
}
}
public class TestClass
{
public string Name { get; set; }
public int ID { get; set; }
public DateTime? DateTime { get; set; }
public string Address { get; set; }
}

Hereby a 'slightly' more clear and shorter version of the accepted answer.
/// <returns>A dynamic object with only the filled properties of an object</returns>
public static object ConvertToObjectWithoutPropertiesWithNullValues<T>(this T objectToTransform)
{
var type = objectToTransform.GetType();
var returnClass = new ExpandoObject() as IDictionary<string, object>;
foreach (var propertyInfo in type.GetProperties())
{
var value = propertyInfo.GetValue(objectToTransform);
var valueIsNotAString = !(value is string && !string.IsNullOrWhiteSpace(value.ToString()));
if (valueIsNotAString && value != null)
{
returnClass.Add(propertyInfo.Name, value);
}
}
return returnClass;
}

You could take advantage of the dynamic type:
class Program
{
static void Main(string[] args)
{
List<dynamic> list = new List<dynamic>();
dynamic
t1 = new ExpandoObject(),
t2 = new ExpandoObject();
t1.Address = "address1";
t1.ID = 132;
t2.Address = "address2";
t2.ID = 133;
t2.Name = "someName";
t2.DateTime = DateTime.Now;
list.AddRange(new[] { t1, t2 });
// later in your code
list.Select((obj, index) =>
new { index, obj }).ToList().ForEach(item =>
{
Console.WriteLine("Object #{0}", item.index);
((IDictionary<string, object>)item.obj).ToList()
.ForEach(i =>
{
Console.WriteLine("Property: {0} Value: {1}",
i.Key, i.Value);
});
Console.WriteLine();
});
// or maybe generate JSON
var s = JsonSerializer.Create();
var sb=new StringBuilder();
var w=new StringWriter(sb);
var items = list.Select(item =>
{
sb.Clear();
s.Serialize(w, item);
return sb.ToString();
});
items.ToList().ForEach(json =>
{
Console.WriteLine(json);
});
}
}

May be interfaces will be handy:
public interface IAdressAndId
{
int ID { get; set; }
string Address { get; set; }
}
public interface INameAndDate
{
string Name { get; set; }
DateTime? DateTime { get; set; }
}
public class TestClass : IAdressAndId, INameAndDate
{
public string Name { get; set; }
public int ID { get; set; }
public DateTime? DateTime { get; set; }
public string Address { get; set; }
}
Creating object:
IAdressAndId t = new TestClass()
{
Address = "address",
ID = 132,
Name = string.Empty,
DateTime = null
};
Also u can put your interfaces in separate namespace and make your class declaration as internal. After that create some public factories which will create the instances of your classes.