Is there a way to execute a string as C# code in ASP.NET 5 with Roslyn?
In my case I want to dynamically convert a string to an linq expression.
For example:
obj.SomeFunc( "x => x.Username".ToLinqExpression() );
Or something like:
Eval("obj.SomeFunc(x => x.Username); ");
Is this possible in ASP.NET 5?
You can do something like this using Roslyn Scripting. For example:
public class Globals
{
public ObjType obj;
}
…
CSharpScript.EvaluateAsync(
"obj.SomeFunc(x => x.Username)", globals: new Globals { obj = obj });
As already suggested, you can try Dynamic Linq. I have used to generate sorting based on dynamic properties and it seems to work very well.
Evaluating a string requires compilation and an expression tree can easily be built using the Expression Class and compiling a delegate.
Expression class is in System namespace.
Here are a couple of ways:
static Func<int, int, int, int, int> delInt = (i, j, k, l) => i + j * k - l;
int rslt1 = delInt(2, 3, 4, 5); // evaluates lambda and returns int
static Func<int> delInt1 = () => 2 + 3 * 4 - 5; // type the expression after => instead of assigning it to a string.
int rslt2 = delInt1(); // takes no parameters and returns int result.
