Interceptors

provide information about the property-access and allows the interceptor to forward the call to the next handler.

For getters (access.setter === false), this is the value of the property, for setters true or false

access => {
  if(access.setter) {
    // Overwrite the value the property is to be set to
    access.value = "Hello"
    return access.next();
  }
  // getter
  let value = access.next();

  // Modify result
  value += 1;
  return value;
}

access

GetterInterceptor

SetterInterceptor

of the invocation

Modified result of the invocation

result => {
  // Modify method result
  result += 1;
  return result;
}

after

MethodInterceptor

Arguments of the method invocation

Modified arguments

args => {
  // Modify method arguments
  args.push("Additional argument");
  // Or swap them
  return ["Replacement", "Argument"];
}

after

MethodInterceptor

of the property. This is (the potentially modified) value of the property.

Modified value of the property.

value => {
  // Modify result
  value += 1;
  return value;
}

getter

AccessInterceptor

provide information about the invocation and allows the interceptor to forward the call to the next handler.

The result of the method invocation

invocation => {
  // Access and modify argument
  invocation.args = ["Modified", "Arguments"];

  // Access and modify 'this'-context of the called method
  invocation.this = that;

  // Delegate call
  let result: any = invocation.next();

  // Modify result
  result += 1;
  return result;
}

around

AfterInterceptor

BeforeInterceptor

to be assigned to the property (this has potentially already been modified by previous interceptor)

Modified value to be assigned to the property.

value => {
  // Modify assigned value
  value += 1;
  return value;
}

setter

AccessInterceptor