/// <summary>
/// Creates a new <see cref="JsBinding"/> instance.
/// </summary>
public JsBinding(JsContextScope scope, JsBinder binder, JsInterop interop, JavaScriptValue value)
{
_scope = scope;
_binder = binder;
_interop = interop;
_value = value;
}
/// <summary>
/// Determine if the <see cref="Type"/> provided is suitable to be passed the provided JS value.
/// </summary>
public static bool IsAssignable(JavaScriptValue value, JsBinder bindingData, Type toType)
{
switch (value.ValueType)
{
case JavaScriptValueType.Undefined: return(true);
case JavaScriptValueType.Null: return(true);
case JavaScriptValueType.Boolean: return(IsBoolType(toType));
case JavaScriptValueType.String: return(IsStringType(toType));
case JavaScriptValueType.Number: return(IsNumberType(toType));
case JavaScriptValueType.Function: return(IsFunctionType(toType));
case JavaScriptValueType.Array: return(IsArrayType(value, bindingData, toType));
case JavaScriptValueType.TypedArray: return(IsArrayType(value, bindingData, toType));
case JavaScriptValueType.Object: return(IsObjectAssignable(value, bindingData, toType));
default:
{
Log.Warning(null, "IsAssignable doesn't support the JS Value Type: {0}", value.ValueType);
return(false);
}
}
}
/// <summary>
/// This method should be used to perform type checking when the <see cref="JavaScriptValue"/> is of
/// value type <see cref="JavaScriptValueType.Object"/>. It will use the live binding data to reverse
/// lookup types bound to JS objects.
/// </summary>
private static bool IsObjectAssignable(JavaScriptValue value, JsBinder bindingData, Type toType)
{
// Naive Case
if (typeof(object) == toType)
{
return(true);
}
// Attempt to locate the type from live binding data, determine if assignable
if (TryGetJsObjectType(value, bindingData, out var objectType))
{
return(toType.IsAssignableFrom(objectType));
}
return(false);
}
/// <summary>
/// Attempts to get the <see cref="Type"/> bound to the JS value as long as the JS value has
/// a the value type of <see cref="JavaScriptValueType.Object"/>
/// </summary>
private static bool TryGetJsObjectType(JavaScriptValue value, JsBinder bindingData, out Type type)
{
if (!value.IsValid || value.ValueType != JavaScriptValueType.Object)
{
type = typeof(void);
return(false);
}
var boundObject = bindingData.ObjectLinkedTo(value);
if (null == boundObject)
{
type = typeof(void);
return(false);
}
type = boundObject.GetType();
return(true);
}
/// <summary>
/// Determines whether or not the <see cref="Type"/> is a valid JS type for array conversions.
/// </summary>
private static bool IsArrayType(JavaScriptValue value, JsBinder bindingData, Type type)
{
if (!type.IsArray)
{
return(false);
}
// Check length, if empty, we can assume it matches any of the array types
var length = value.GetProperty(JavaScriptPropertyId.FromString("length")).ToInt32();
if (length <= 0)
{
return(true);
}
// Look at the first element, type check against the host array element type
var firstElement = value.GetIndexedProperty(JavaScriptValue.FromInt32(0));
var elementType = type.GetElementType();
return(IsAssignable(firstElement, bindingData, elementType));
}
/// <summary>
/// Creates a new <see cref="JsInterop"/> instance.
/// </summary>
/// <param name="scope"></param>
public JsInterop(JsExecutionContext context, JsContextScope scope, JsBinder binder)
{
_context = context;
_scope = scope;
_binder = binder;
}
/// <summary>
/// Creates a new <see cref="JsBindingBuilder"/> instance.
/// </summary>
public JsBindingBuilder(JsContextScope scope, JsBinder binder, JsInterop interop)
{
_scope = scope;
_binder = binder;
_interop = interop;
}