mirror_dispatcher

Description:

mirror dispatcher

MirrorDispatcher implements [Dispatcher] by introspecting a class instance
using [dart:mirrors]. dart:mirrors allows you to invoke an instance's methods
by their string names.
Construct a [MirrorDispatcher] with a class instance.
MirrorDispatcher.dispatch("someMethod") will return a Future of whatever
value it returns.
This is for JSON-RPC, so there are some restrictions. A method can only be invoked with
positional or named parameters, not both. Optional parameters should work as expected.
MirrorDispatcher is mainly a wrapper around dart:mirrors.
For any method dispatched, Dispatcher returns either the return value of
the method or instances of one of three "Exception" classes. Most errors
will be corralled into these objects, so that runtime exceptions don't get
thrown, instead are returned in an orderly manner.
Usage #
A simple usage example:
import 'package:mirror_dispatcher/mirror_dispatcher.dart';

/// Look in test/mirror_dispatcher_test.dart for additional examples.

/// Make a class with the API we want. Something silly but instructive.
///
/// Hold count in Foo.
class Foo {
num _count = 0;

/// initialize with a count
Foo(this._count);

/// increment with an optional positional parameter
void increment([num aNumber = 1]) => _count += aNumber;

/// decrement with a required named parameter
void decrement({required num aNumber}) => _count -= aNumber;

/// get the current value of count
num getCount() => _count;

/// we decrement by 2 a lot.
num goTwoLess() {
_count -= 2;
return _count;
}
}

void main() async {
/// make a dispatcher with an initialized instance of Foo class
var dispatcher = MirrorDispatcher(Foo(29));

/// dispatch a method with a parameter
await dispatcher.dispatch('increment', 4);

/// get the new value
var c = await (dispatcher.dispatch('getCount'));
printCount(c); // 33

/// dispatch a method with a named parameter
await dispatcher.dispatch('decrement', {'aNumber': 18});
var d = await (dispatcher.dispatch('getCount'));
printCount(d); // 15

/// dispatch a method without a parameter
await dispatcher.dispatch('increment');
var e = await (dispatcher.dispatch('getCount'));
printCount(e); // 16

var f = await dispatcher.dispatch('goTwoLess');
printCount(f); // 14
}

void printCount(num aCount) {
print('the currentCount is $aCount');
}

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Features and bugs #
Please file feature requests and bugs at the issue tracker.