We Keep Coding

Load related data with IgnoreQueryFilter

What is the best way to Update all related Entities when working with Queryfilter?
All my Entities inherit from a BaseClass with "IsDeleted" Property.
When i build my Context i use
if (table.GetProperties().Any(column => column.ClrType == typeof(bool) && column.Name == "IsDeleted"))
{
var parameter = Expression.Parameter(table.ClrType);
var propertyMethodInfo = typeof(EF).GetMethod("Property").MakeGenericMethod(typeof(bool));
var isDeletedProperty = Expression.Call(propertyMethodInfo, parameter, Expression.Constant("IsDeleted"));
BinaryExpression compareExpression = Expression.MakeBinary(ExpressionType.Equal, isDeletedProperty, Expression.Constant(false));
var lambda = Expression.Lambda(compareExpression, parameter);
builder.Entity(table.ClrType).HasQueryFilter(lambda);
}
the HasQueryfilter to Ignore all deleted Entity. SoftDelete.
When i try to Update my all Collections, i only get the filterd Collections. So its never possible to Update my IsDelete Property with a true value.
if (entry.State == EntityState.Modified)
{
foreach (var collectionEntry in _context.Entry(dbMember).Collections)
{
await collectionEntry.LoadAsync();
foreach (var o in collectionEntry.CurrentValue)
{
var entity = o as BaseEntity;
entity.IsDeleted = dbMember.IsDeleted;
}
}
}
What i need is something like
await collectionEntry.LoadAsync().IgnoreQueryFilters().

Turning XDocument/Elements into a C# Class Object

I am having a problem trying to read a XML from XDocument, converting the Elements into an actual Class Object. Reason why im not using XmlSerialization is because i need to use PropertyGrid.
Cant get it to create the children with inside a class it self.
Error Given
System.NullReferenceException occurred
HResult=0x80004003
Message=Object reference not set to an instance of an object.
Source=XmlTest2
StackTrace:
at XmlTest2.Program.Main(String[] args) in Program.cs:line 22
var list = q.GetElementsByClass<Targets>();
foreach (var p in list)
{
Console.WriteLine(p.grouping.name);
}
This will work
var list = q.GetElementsByClass<Grouping>();
foreach (var p in list)
{
Console.WriteLine(p.name);
}
Full code and XML located here
XMLFile1.xml
Program.cs
public T[] GetElementsByClass<T>() where T : class, new()
{
Assembly asm = Assembly.GetExecutingAssembly();
var typeName = typeof(T).Name;
var type = asm.GetTypes().First(t => t.Name == typeName);
if (type == null) throw new ArgumentNullException(nameof(type));
return _doc.Descendants(_parent)
.Select(item =>
{
var p = Activator.CreateInstance(type) as T;
foreach (var prop in item.Descendants())
{
var pi = p.GetType().GetProperty(prop.Name.LocalName);
if (pi == null) continue;
object newVal = Convert.ChangeType(prop.Value, pi.PropertyType);
pi.SetValue(p, newVal, null);
}
return p;
}).ToArray();
}

Can a get DbType from Dapper DynamicParameters?

I need iterate through Dapper DynamicParameters. So, I check this answer to get value of parameter.
foreach (var paramName in parameters.ParameterNames)
{
var value = ((SqlMapper.IParameterLookup)parameters)[paramName];
}
Now, I need parameter DbType. Is it possible to get this information?

I dont know if Dapper provides a better solution for this or not, but thanks to reflection, there is nothing impossible!
var t = parameters.GetType().GetField("parameters", BindingFlags.NonPublic | BindingFlags.Instance);
if (t != null)
{
foreach (DictionaryEntry dictionaryEntry in (IDictionary)t.GetValue(parameters))
{
var dbType = (DbType)dictionaryEntry.Value?.GetType().GetProperty("DbType")?.GetValue(dictionaryEntry.Value);
}
}

You can do this! Please check the code below:
private List<DbType> GetParameterType<T>()
{
var type = typeof(T);
var properties = type.GetProperties().Select(property => property.PropertyType.Name).ToList();
var dbTypes = new List<DbType>();
foreach (var prop in properties)
{
var tryParse = Enum.TryParse<DbType>(prop, out var result);
if (tryParse)
dbTypes.Add(result);
}
return dbTypes;
}
And then, the call of this is simple: var dbTypes = GetParameterType<T>(); where T is your object

Generate POCO from dynamic in C#

Is there anything built into .NET 4.5 that will generate a string C# POCO from a dynamic with all auto-implemented properties?
If not, is there anything built into .NET that will give you (something like a) List<KeyValuePair<string, Type>> so that we can generate a POCO according to the pseudo-code:
foreach (var kvp in list)
{
builder.AppendFormat("public {0} {1} {{ get; set; }}", kvp.Value, kvp.Key);
}
Finally, are there any well-known libraries that can assist with this sort of very basic code generation?

You can use compileassemblyfromsource to compile your string,
http://msdn.microsoft.com/en-us/library/system.codedom.compiler.codedomprovider.compileassemblyfromsource(v=vs.110).aspx
var csc = new CSharpCodeProvider(new Dictionary<string, string>() { { "CompilerVersion", "v4.0" } });
var cp = new CompilerParameters()
{
GenerateExecutable = false,
GenerateInMemory = true
};
cp.ReferencedAssemblies.Add("mscorlib.dll");
cp.ReferencedAssemblies.Add("System.dll");
cp.ReferencedAssemblies.Add("System.Core.dll");
// The string can contain any valid c# code
// A valid class need to be created with its own properties.
var s = "public class POCOClass{ public int ID {get {return 1;}} }";
// "results" will usually contain very detailed error messages
var results = csc.CompileAssemblyFromSource(cp, s);
var type = results.CompiledAssembly.GetType("POCOClass");
var obj = (dynamic)Activator.CreateInstance(type);
var output = obj.ID;
// or
var output_ = obj.GetType().GetProperty("ID").GetValue(obj, null);
You need to define a class for your properties such as called POCOClass.
EDIT:
public static T CopyObjectFromExpando<T>(this object s) where T : class
{
var source = (ExpandoObject)s;
// Might as well take care of null references early.
if (source == null)
{
throw new ArgumentNullException("s");
}
var propertyMap = typeof(T).GetProperties().ToDictionary(p => p.Name.ToLowerInvariant(), p => p);
var destination = Activator.CreateInstance<T>();
// By iterating the KeyValuePair<string, object> of
// source we can avoid manually searching the keys of
// source as we see in your original code.
foreach (var kv in source)
{
PropertyInfo p;
if (propertyMap.TryGetValue(kv.Key.ToLowerInvariant(), out p))
{
var propType = p.PropertyType;
if (kv.Value == null)
{
if (!propType.IsNullable() && propType != typeof(string))
{
// Throw if type is a value type
// but not Nullable<>
throw new ArgumentException("not nullable");
}
}
else if (propType.IsEnum)
{
var enumvalue = Enum.ToObject(propType, kv.Value);
p.SetValue(destination, enumvalue, null);
continue;
}
else if (propType == typeof(bool) && kv.Value.GetType() != typeof(bool))
{
var boolvalue = Convert.ToBoolean(kv.Value);
p.SetValue(destination, boolvalue, null);
continue;
}
else if (propType.IsNullable())
{
var nullType = Nullable.GetUnderlyingType(propType);
var value = Convert.ChangeType(kv.Value, nullType);
p.SetValue(destination, value, null);
continue;
}
else if (kv.Value.GetType() != propType)
{
// You could make this a bit less strict
// but I don't recommend it.
throw new ArgumentException("type mismatch");
}
p.SetValue(destination, kv.Value, null);
}
}
return destination;
}

ImpromptuInterface, open source on Nuget
PM> Install-Package ImpromptuInterface
Has ActLikeProperties
by using ImpromptuInterface
Impromput.ActLikeProperties(dynObj, list.ToDictionary(k=>k.Key,v=>v.Value))
This emits a poco dlr proxy around the dynObj
The intent was to be able to bridge simple dynamic objects (like expando) to old code that uses reflection. But generally it's better to do what ImpromptuInterface's main function, which is wrap dynamic objects with statically declared interfaces.

Using Reflection.Emit to copy a custom attribute to another method

I am trying to generate a new set of wcf interfaces based on existing interfaces.
I am using the Reflection.Emit namespace to accomplish this. My problem is how to copy the old custom attributes from one method to the new method. Every example I have seen of SetCustomAttributes() requires knowing the attribute type beforehand. I need to discover the attribute type at runtime. Any thoughts?

The answer you (frjames) posted is close, but doesn't account for property initializers like...
[ServiceBehavior(Name="ServiceName")]
However, the idea of converting CustomAttributeData to a CustomAttributeBuilder for use in Reflection.Emit is right on.
I ended up having to do this for an open source project (Autofac) and came up with this extension method:
public static CustomAttributeBuilder ToAttributeBuilder(this CustomAttributeData data)
{
if (data == null)
{
throw new ArgumentNullException("data");
}
var constructorArguments = new List<object>();
foreach (var ctorArg in data.ConstructorArguments)
{
constructorArguments.Add(ctorArg.Value);
}
var propertyArguments = new List<PropertyInfo>();
var propertyArgumentValues = new List<object>();
var fieldArguments = new List<FieldInfo>();
var fieldArgumentValues = new List<object>();
foreach (var namedArg in data.NamedArguments)
{
var fi = namedArg.MemberInfo as FieldInfo;
var pi = namedArg.MemberInfo as PropertyInfo;
if (fi != null)
{
fieldArguments.Add(fi);
fieldArgumentValues.Add(namedArg.TypedValue.Value);
}
else if (pi != null)
{
propertyArguments.Add(pi);
propertyArgumentValues.Add(namedArg.TypedValue.Value);
}
}
return new CustomAttributeBuilder(
data.Constructor,
constructorArguments.ToArray(),
propertyArguments.ToArray(),
propertyArgumentValues.ToArray(),
fieldArguments.ToArray(),
fieldArgumentValues.ToArray());
}
That one accounts for all the ways to initialize the attribute.

Here is the answer I came up with after some more research.
CustomAttributeBuilder ct = AddAttributesToMemberInfo(methodInfo);
if (ct != null)
{
methodBuilder.SetCustomAttribute(ct);
}
CustomAttributeBuilder AddAttributesToMemberInfo(MemberInfo oldMember)
{
CustomAttributeBuilder ct = null;
IList<CustomAttributeData> customMethodAttributes = CustomAttributeData.GetCustomAttributes(oldMember);
foreach (CustomAttributeData att in customMethodAttributes)
{
List<object> namedFieldValues = new List<object>();
List<FieldInfo> fields = new List<FieldInfo>();
List<object> constructorArguments = new List<object>();
foreach (CustomAttributeTypedArgument cata in att.ConstructorArguments)
{
constructorArguments.Add(cata.Value);
}
if (att.NamedArguments.Count > 0)
{
FieldInfo[] possibleFields = att.GetType().GetFields();
foreach (CustomAttributeNamedArgument cana in att.NamedArguments)
{
for (int x = 0; x < possibleFields.Length; x++)
{
if (possibleFields[x].Name.CompareTo(cana.MemberInfo.Name) == 0)
{
fields.Add(possibleFields[x]);
namedFieldValues.Add(cana.TypedValue.Value);
}
}
}
}
if (namedFieldValues.Count > 0)
{
ct = new CustomAttributeBuilder(att.Constructor, constructorArguments.ToArray(), fields.ToArray(), namedFieldValues.ToArray());
}
else
{
ct = new CustomAttributeBuilder(att.Constructor, constructorArguments.ToArray());
}
}
return ct;
}

The code from Travis Illig needs amendment as below to work with .Net Core:
foreach (var namedArg in data.NamedArguments)
{
string argName = namedArg.MemberName;
var fi = data.AttributeType.GetField(argName);
var pi = data.AttributeType.GetProperty(argName);

try this:
MethodInfo mi;
//...
object[] custAttribs = mi.GetCustomAttributes(false);
foreach (object attrib in custAttribs)
attrib.GetType();
i assume you have MethodInfo for your methods