As of today, there are four available approaches, two of them requiring a certain storage backend: Django-eav (the original package is no longer mantained but has some thriving forks) This solution is based on Entity Attribute Value data model, essentially, it uses several tables to store dynamic attributes of objects. Great parts about this solution … Read more
dynamic MyDynamic = new System.Dynamic.ExpandoObject(); MyDynamic.A = “A”; MyDynamic.B = “B”; MyDynamic.C = “C”; MyDynamic.Number = 12; MyDynamic.MyMethod = new Func<int>(() => { return 55; }); Console.WriteLine(MyDynamic.MyMethod()); Read more about ExpandoObject class and for more samples: Represents an object whose members can be dynamically added and removed at run time.
The dynamic keyword is used to declare variables that should be late-bound. If you want to use late binding, for any real or imagined type, you use the dynamic keyword and the compiler does the rest. When you use the dynamic keyword to interact with a normal instance, the DLR performs late-bound calls to the … Read more
The instanceof-operator is called is in Dart. The spec isn’t exactly friendly to a casual reader, so the best description right now seems to be http://www.dartlang.org/articles/optional-types/. Here’s an example: class Foo { } main() { var foo = new Foo(); if (foo is Foo) { print(“it’s a foo!”); } }
According to MSDN the declaration shows it is implementing IDictionary: public sealed class ExpandoObject : IDynamicMetaObjectProvider, IDictionary<string, Object>, ICollection<KeyValuePair<string, Object>>, IEnumerable<KeyValuePair<string, Object>>, IEnumerable, INotifyPropertyChanged You can use this to see if a member is defined: var expandoObject = …; if(((IDictionary<String, object>)expandoObject).ContainsKey(“SomeMember”)) { // expandoObject.SomeMember exists. }
var is static typed – the compiler and runtime know the type – they just save you some typing… the following are 100% identical: var s = “abc”; Console.WriteLine(s.Length); and string s = “abc”; Console.WriteLine(s.Length); All that happened was that the compiler figured out that s must be a string (from the initializer). In both … Read more
This snippet compiles the Rules into fast executable code (using Expression trees) and does not need any complicated switch statements: (Edit : full working example with generic method) public Func<User, bool> CompileRule(Rule r) { var paramUser = Expression.Parameter(typeof(User)); Expression expr = BuildExpr(r, paramUser); // build a lambda function User->bool and compile it return Expression.Lambda<Func<User, bool>>(expr, … Read more
Wrap them in {}: ${“file” . $i} = file($filelist[$i]); Working Example Using ${} is a way to create dynamic variables, simple example: ${‘a’ . ‘b’} = ‘hello there’; echo $ab; // hello there
Once you have your PropertyInfo (from GetProperty), you need to call GetValue and pass in the instance that you want to get the value from. In your case: d.GetType().GetProperty(“value2”).GetValue(d, null);
Using a cell renderer. Use the renderer name of your choice when configuring the column: const container = document.getElementById(‘container’); const hot = new Handsontable(container, { data: someData, columns: [{ renderer: ‘numeric’ }] });