ClearScript Examples
The examples below use the following namespaces:
C#
using System;
using Microsoft.ClearScript;
using Microsoft.ClearScript.JavaScript;
using Microsoft.ClearScript.V8;
The following examples demonstrate selected ClearScript features:
C#
// create a script engine
using (var engine = new V8ScriptEngine())
{
// expose a host type
engine.AddHostType("Console", typeof(Console));
engine.Execute("Console.WriteLine('{0} is an interesting number.', Math.PI)");
// expose a host object
engine.AddHostObject("random", new Random());
engine.Execute("Console.WriteLine(random.NextDouble())");
// expose entire assemblies
engine.AddHostObject("lib", new HostTypeCollection("mscorlib", "System.Core"));
engine.Execute("Console.WriteLine(lib.System.DateTime.Now)");
// create a host object from script
engine.Execute(@"
birthday = new lib.System.DateTime(2007, 5, 22);
Console.WriteLine(birthday.ToLongDateString());
");
// use a generic class from script
engine.Execute(@"
Dictionary = lib.System.Collections.Generic.Dictionary;
dict = new Dictionary(lib.System.String, lib.System.Int32);
dict.Add('foo', 123);
");
// call a host method with an output parameter
engine.AddHostObject("host", new HostFunctions());
engine.Execute(@"
intVar = host.newVar(lib.System.Int32);
found = dict.TryGetValue('foo', intVar.out);
Console.WriteLine('{0} {1}', found, intVar);
");
// create and populate a host array
engine.Execute(@"
numbers = host.newArr(lib.System.Int32, 20);
for (var i = 0; i < numbers.Length; i++) { numbers[i] = i; }
Console.WriteLine(lib.System.String.Join(', ', numbers));
");
// create a script delegate
engine.Execute(@"
Filter = lib.System.Func(lib.System.Int32, lib.System.Boolean);
oddFilter = new Filter(function(value) {
return (value & 1) ? true : false;
});
");
// use LINQ from script
engine.Execute(@"
oddNumbers = numbers.Where(oddFilter);
Console.WriteLine(lib.System.String.Join(', ', oddNumbers));
");
// use a dynamic host object
engine.Execute(@"
expando = new lib.System.Dynamic.ExpandoObject();
expando.foo = 123;
expando.bar = 'qux';
delete expando.foo;
");
// call a script function
engine.Execute("function print(x) { Console.WriteLine(x); }");
engine.Script.print(DateTime.Now.DayOfWeek);
// examine a script object
engine.Execute("person = { name: 'Fred', age: 5 }");
Console.WriteLine(engine.Script.person.name);
// read a JavaScript typed array
engine.Execute("values = new Int32Array([1, 2, 3, 4, 5])");
var values = (ITypedArray<int>)engine.Script.values;
Console.WriteLine(string.Join(", ", values.ToArray()));
}
The examples above generate the following output (some results are random or time-specific):
Console
3.14159265358979 is an interesting number.
0.715555223503874
5/11/2017 12:15:32 PM
Tuesday, May 22, 2007
True 123
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19
1, 3, 5, 7, 9, 11, 13, 15, 17, 19
Thursday
Fred
1, 2, 3, 4, 5