If I know the name of a function, is it possible to get its parameters? - reflection

Question

Dart code:
void hello(String name) {
print(name);
}
main() {
var funcName = "hello";
// how to get the parameter `String name`?
}
Using the function name as a string, "hello", is it possible to get the parameter String name of the real function hello ?

Answer 1

You can use mirrors to do that.
import 'dart:mirrors';
void hello(String name) {
print(name);
}
main() {
var funcName = "hello";
// get the top level functions in the current library
Map<Symbol, MethodMirror> functions =
currentMirrorSystem().isolate.rootLibrary.functions;
MethodMirror func = functions[const Symbol(funcName)];
// once function is found : get parameters
List<ParameterMirror> params = func.parameters;
for (ParameterMirror param in params) {
String type = MirrorSystem.getName(param.type.simpleName);
String name = MirrorSystem.getName(param.simpleName);
//....
print("$type $name");
}
}

Answer 2

You get this information through reflection (which it is not yet fully completed):
library hello_library;
import 'dart:mirrors';
void main() {
var mirrors = currentMirrorSystem();
const libraryName = 'hello_library';
var libraries = mirrors.findLibrary(const Symbol(libraryName));
var length = libraries.length;
if(length == 0) {
print('Library not found');
} else if(length > 1) {
print('Found more than one library');
} else {
var method = getStaticMethodInfo(libraries.first, const Symbol('hello'));
var parameters = getMethodParameters(method);
if(parameters != null) {
for(ParameterMirror parameter in parameters) {
print('name: ${parameter.simpleName}:, type: ${parameter.type.simpleName}');
}
}
}
}
MethodMirror getStaticMethodInfo(LibraryMirror library, Symbol methodName) {
if(library == null) {
return null;
}
return library.functions[methodName];
}
List<ParameterMirror> getMethodParameters(MethodMirror method) {
if(method == null) {
return null;
}
return method.parameters;
}
void hello(String name) {
print(name);
}