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Using `this.super()` and `this.super.method()` via any kind of object or prototype (proof of concept)
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var withSuperContext = (function (Object) { | |
//! (c) Andrea Giammarchi | |
var | |
defineProperty = Object.defineProperty, | |
getPrototypeOf = Object.getPrototypeOf, | |
setPrototypeOf = Object.setPrototypeOf || | |
function (o, p) { o.__proto__ = p; }, | |
handler = { | |
get: function get(target, property, receiver) { | |
return function () { | |
var | |
self = target.self, | |
proto = getPrototypeOf(self), | |
method = self[property], | |
parent = proto, | |
result | |
; | |
do { | |
parent = getPrototypeOf(parent); | |
} while (method === parent[property]); | |
setPrototypeOf(self, parent); | |
try { | |
result = parent[property].apply(self, arguments); | |
setPrototypeOf(self, proto); | |
} catch(e) { | |
setPrototypeOf(self, proto); | |
throw e; | |
} | |
return result; | |
}; | |
} | |
} | |
; | |
return function withSuperContext(object) { | |
defineProperty( | |
typeof object === 'function' ? | |
object.prototype : object, | |
'super', | |
{ | |
get: function get() { | |
var | |
self = this, | |
parent = function () { | |
return proxy.constructor.apply(self, arguments); | |
}, | |
proxy = new Proxy(parent, handler) | |
; | |
parent.self = self; | |
return proxy; | |
} | |
} | |
); | |
return object; | |
}; | |
}(Object)); |
This does not seem to work if C
does not define the method
: When B.prototype.method
does call super
, the self
will refer to the C instance, proto
to C.prototype
, and you'll get an infinite recursion when B
s method
calls itself.
Instead of assuming that the super
was gotten in a method on the current direct prototype of this
/self
, you rather should pass the object
/object.prototype
into the proxy to be used as the proto
.
Also you will totally want to wrap setPrototypeOf(self, proto);
in a finally
clause, or otherwise the prototype chain will explode in your face when one of the method throws an exception.
which part of quick and dirty wasn't clear? it's a proof of concept ;-)
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Usage example