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Javascript console output before and after method call with AOP

I would like to measure the computing time of methods.
A nice way is (How do you performance test JavaScript code?) with console.time('Function #1'); and console.timeEnd('Function #1');
My idea is to add these console outputs on lifecycle-methods. In this case using SAPUI5 like createContent:funtion(){}; methods.
This should be possible with AOP using before() and after() to runt the time counting.
Which AOP framework would you suggest and how to implement it with the need of modifying the identification string "Function #1" automatically?

There actually is no need for aspects in Javascript since you can change any function of any object at any time. JavaScript prototypes allows you to manipulate method implementations of all instances of an object at runtime. Here are two approaches for what you plan.
You could use a generic wrapper function:
var measureId = 0;
var fnMeasureFunction = function(fnToMeasure) {
console.time('measure'+ measureId);
fnToMeasure();
console.timeEnd('measure'+ measureId);
measureId++;
}
Admittedly that requires you to change your actual code...
For static functions or functions that belong to a prototype you could also do sth. like this from the outside without the need of any change to your existing code:
// any static function
var measureId = 0;
var fnOriginalFunction = sap.ui.core.mvc.JSViewRenderer.render;
sap.ui.core.mvc.JSViewRenderer.render = function() {
console.time('measure'+ measureId);
fnOriginalFunction.apply(this, arguments);
console.timeEnd('measure'+ measureId);
measureId++;
}
// any prototype function
var fnOriginalFunction = sap.m.Button.prototype.ontouchstart;
sap.m.Button.prototype.ontouchstart= function() {
console.time('measure'+ measureId);
fnOriginalFunction.apply(this, arguments);
console.timeEnd('measure'+ measureId);
measureId++;
}

This should be possible with AOP using before() and after() to runt the time counting.
As it already got mentioned, one really is not in need of real Aspect-oriented Programming
in order to solve such tasks in JavaScript. But this language might deserve some more standardized
method-modifiers in addition to the already existing bind method.
Please check back with my 2 most recent posts on this matter:
sandwich pattern in javascript code
Can you alter a Javascript function after declaring it?
... and how to implement it with the need of modifying the identification string "Function #1" automatically?
One does not need to since the console's time / timeEnd functionality only has to have
identical entry and exit points for measuring time (like the start/stop trigger of a stopwatch).
So one gets along with exactly the reference of the function/method one is currently running/measuring.
In order to solve the given task I will suggest around only instead of both before and
after for the former generates less overhead. The next code block exemplarily shows a
possible prototypal implementation. It also is the base for the afterwards following example
that finally might solve the OP's task.
(function (Function) {
var
isFunction = function (type) {
return (
(typeof type == "function")
&& (typeof type.call == "function")
&& (typeof type.apply == "function")
);
},
getSanitizedTarget = function (target) {
return ((target != null) && target) || null;
}
;
Function.prototype.around = function (handler, target) { // [around]
target = getSanitizedTarget(target);
var proceed = this;
return (isFunction(handler) && isFunction(proceed) && function () {
return handler.call(target, proceed, handler, arguments);
}) || proceed;
};
}(Function));
The next example takes into account that method-modification essentially relies on
functionality that is bound to an object. It is not just function wrapping. In order
to not loose the context a method is operating on, context has to be delegated /
passed around as target throughout all operations.
For this the example does not modify calculate since it is not bound to an object
but it modifies trigger instead.
var testObject = {
calculate: function (hugeInteger) {
var
i = hugeInteger,
k = 0
;
while (i--) {
k++;
}
return k;
},
trigger: function (hugeInteger) {
this.result = this.calculate(hugeInteger);
},
result: -1
};
console.log("testObject.result : ", testObject.result);
console.log("testObject.trigger(Math.pow(2, 26)) : ", testObject.trigger(Math.pow(2, 26))); // takes some time.
console.log("testObject.result : ", testObject.result);
console.log("testObject.someTrigger(0) : ", testObject.trigger(0)); // logs immediately after.
console.log("testObject.result : ", testObject.result);
testObject.trigger = testObject.trigger.around(function (proceed, interceptor, args) {
// before:
console.time(proceed);
// proceed:
proceed.apply(this, args);
// after:
console.timeEnd(proceed);
}, testObject); // omitting the 2nd argument - the [target] object - might break code that did work before.
console.log("testObject.trigger(Math.pow(2, 26)) : ", testObject.trigger(Math.pow(2, 26)));
console.log("testObject.result : ", testObject.result);
.as-console-wrapper { min-height: 100%!important; top: 0; }
<script>
(function (Function) {
var
isFunction = function (type) {
return (
(typeof type == "function")
&& (typeof type.call == "function")
&& (typeof type.apply == "function")
);
},
getSanitizedTarget = function (target) {
return ((target != null) && target) || null;
}
;
Function.prototype.around = function (handler, target) { // [around]
target = getSanitizedTarget(target);
var proceed = this;
return (isFunction(handler) && isFunction(proceed) && function () {
return handler.call(target, proceed, handler, arguments);
}) || proceed;
};
}(Function));
</script>

how to define global namespace in javascript

is there a way to define global namespace, so that i can call function from this namespace from all my page?
e.g
// in one file i define below code
DefineNameSpace("my.namespace.api", {
addObject: function(obj) {
// store obj into indexDB
},
readAllObject: function() {
// return array of object from indexdb
}
})
// so that in another javascript file i can do
my.namespace.api.addObject({name: "foo", desc: "bar"});
is there a way to implement "DefineNameSpace" method?
Thanks

one way to do it, which is very simple, is this:
my = {
namespace: {
api : {}
}
}
my.namespace.api.addObject = function (obj) { }
you're actually creating objects but in this way it will function as a namespace just as well :)
hm it's not the method you're implementing. But building a namespace with a method would require the function to be called before the script files are loaded where the namespace is used like that, otherwise those lines of code are called before the DefineNamespace method is called and you will run into parts of namespaces that are undefined at that point. With above solution that won't be the case, although it is not dynamic unfortunately.

building a namespace dynamically can be done in the following way:
// the root of the namespace would still be handy to have declared here
var my = {};
function defineNamespace(namespaceStr) {
var namespaceSegments = namespaceStr.split(".");
var namespaceSoFar = null;
// iterate through namespace parts
for (var i = 0; i < namespaceSegments.length; i++) {
var segment = namespaceSegments[i];
if (i == 0) {
// if namespace starts with my, use that
if (segment == "my") {
// set pointer to my
namespaceSoFar = my;
}
else {
// create new root namespace (not tested this, but think this should work)
var otherNamespace = eval(segment);
if (typeof otherNamespace == "undefined") {
eval(segment + " = {};");
}
// set pointer to created root namespace
namespaceSoFar = eval(segment);
}
}
else {
// further build the namespace
if (typeof namespaceSoFar[segment] == "undefined") {
namespaceSoFar[segment] = {};
}
// update the pointer (my -> my.namespace) for use in the next iteration
namespaceSoFar = namespaceSoFar[segment];
}
}
}

Embedding an anonymous function inside of another anonymous function

I have a hash called options. The problem that I'm facing is that options['beforeOpen'] might already be a function, in which case I don't want to overwrite it. I'd like to instead call it then call another function that needs to be called every time
In this example the method that needs to be called every time is methodThatINeedToDo. I thought the code below would accomplish this but it's not working as I expected.
function methodThatINeedToDo(){alert('maintenance');}
var options = {beforeOpen: function(){alert('first');}}
if(typeof options['beforeOpen'] == "function"){
options['beforeOpen'] = function(){options['beforeOpen'].call(); methodThatINeedToAddToDo();}
} else {
options['beforeOpen'] = methodThatINeedToDo;
}

The problem is that within the function you're defining to override options['beforeOpen'], you're using options['beforeOpen'], which by that time has been overwritten!
You need to cache it and use the cached value within your new function:
var cachedBeforeOpen = options.beforeOpen;
if (typeof cachedBeforeOpen == "function") {
options.beforeOpen = function() {
cachedBeforeOpen.call();
methodThatINeedToDo();
};
} else {
options.beforeOpen = methodThatINeedToDo;
}

Simply always call methodThatINeedToDo, since you want to and in there check to see if you should call your options method:
function methodThatINeedToDo(){
options.beforeOpen && options.beforeOpen();
alert('maintenance');
}

That really smells like the wrong solution. Why not Publish/Subscribe pattern?
Here's a little example: http://jsfiddle.net/ajyQH/
$(function() {
var yourObj = { yourFct : [] };
$('#btn').click(function() {
yourObj.yourFct.push(function() {
$('#testibert').append($('<p>').text('hallo'));
});
});
$('#btn_exec').click(function() {
var len = yourObj.yourFct.length;
for(var i = 0; i < len; i++) {
yourObj.yourFct[i]();
}
});
});

var oldCall = options['beforeOpen'];
var newCall = function(){
oldCall();
methodThatINeedToAddToDo();
};
options['beforeOpen'] = newCall;

Javascript Scope - including without passing or making global

I'm working on some script for a set of functions that all operate from one call and take a large number of parameters to return one value. The main function requires the use of 11 other functions which need to work with the same parameters. I have it structured somewhat like this:
function mainfunction(param1, param2, ..., param16)
{
//do a bunch of stuff with the parameters
return output;
}
function secondaryfunction1()
{
//gets called by mainfunction
//does a bunch of stuff with the parameters from mainfunction
}
Is there anything I can do to make the parameters passed to mainfunction available to all the secondary functions without passing them or making them global variables? If not, that's fine, I'll pass them as parameters - I'm curious as to whether or not I can do it more elegantly.

You can place the definition of secondaryfunction1 inside mainfunction:
function mainfunction(param1, param2, ..., param16){
function secondaryfunction1() {
// use param1, param2, ..., param16
}
secondaryfunction1();
}
Update:
As #dystroy pointed out, this is viable if you don't need to call secondaryfunction1 somewhere else. Where the list of parameters would be coming from in this case - I don't know.

You could use arguments to pass to secondaryFunction1 all the arguments of mainfunction. But that would be silly.
What you should probably do, and what is usually done, is embed all the parameters in an "options" object :
function mainfunction(options){
secondaryfunction1(options);
}
function secondaryfunction1(options) {
// use options.param1, etc.
}
// let's call it
mainfunction({param1: 0, param2: "yes?"});
This leds to other advantages, like
naming the parameters you pass, it's not a good thing for maintenance to have to count the parameters to know which one to change. No sane library would let you pass 16 parameters as direct unnamed arguments to a function
enabling you to pass only the needed parameters (the other ones being default)

#Igor 's answer (or some variation) is the way to go. If you have to use the functions elsewhere, though (as #dystroy pointed out), then there is another possibility. Combine your parameters together into an object, and pass that object to the secondary functions.
function combineEm() {
// Get all parameters into an array.
var args = [].slice.call(arguments, 0),
output = {},
i;
// Now put them in an object
for (i = 0; i < args.length; i++) {
output["param" + i] = args[i];
}
return output;
}
From your main function, you can do:
function mainfunction(param1, param2, ..., param16) {
var params = combineEm(param1, param2, ..., param16);
var output = secondaryfunction(params);
// etc.
return output;
}

Edit: I just wanted to clarify that all of the proposed suggestions so far do work. They just each have their own trade-offs/benefits.
I tried just suggesting some changes to other answers, but ultimately I felt like I needed to just post my solution to this.
var externalFn = function(options) {
var str = options.str || 'hello world';
alert(str);
};
var main = function(options) {
var privateMethod = function() {
var str = options.str || "foobar";
alert("str: " + str);
};
// Bind a private version of an external function
var privateMethodFromExternal = externalFn.bind(this, options);
privateMethod();
privateMethodFromExternal();
};
main({ str: "abc123"});
// alerts 'str: abc123'
// alerts 'abc123'
main({});
// alerts 'str: foobar'
// alerts 'hello world'
It seems like the main point of the question is that the functions used by the 'main function' shouldn't have to keep having the options/context passed to them.
This example shows how you can use privateMethods inside the function
It also shows how you can take external functions (that you presumably use outside of main) and bind a private method version of them for use inside main.
I prefer using some sort of 'options' object, but that aspect isn't really that important to the question of scoping that the OP was really asking about. You could use 'regular' parameters as well.
This example can be found on codepen.

Here's an incredibly naughty solution, if you're interested in that sort of thing.
var f1 = function() {
var a = 1;
var _f2 = f2.toString().replace(/^function[^{}]+{/, '');
_f2 = _f2.substr(0, _f2.length - 2);
eval(_f2);
}
var f2 = function(a) {
var a = a || 0;
console.log(a);
}
f2(); // logs 0
f1(); // logs 1
It executes the contents of some external function entirely in the current scope.
However, this sort of trickery is almost definitely an indicator that your project is mis-organized. Calling external functions should usually be no more difficult than passing an object around, as dystroy's answer suggests, defining the function in-scope, as Igor's answer suggests, or by attaching some external function to this and writing your functions primarily against the properties of this. Like so:
var FunLib = {
a : 0,
do : function() {
console.log(this.a);
}
}
var Class = function() {
this.a = 1;
this.do = FunLib.do;
this.somethingThatDependsOnDo = function() {
this.a++;
this.do();
}
}
var o = new Class();
FunLib.do() // 0
o.do() // 1
o.somethingThatDependsOnDo(); // 2
o.do() // 2 now
Similarly, and possibly better-solved with a class hierarchy.
function BasicShoe {
this.steps_taken = 0;
this.max_steps = 100000;
this.doStep = function() {
this.steps_taken++;
if (this.steps_taken > this.max_steps) {
throw new Exception("Broken Shoe!");
}
}
}
function Boot {
this.max_steps = 150000;
this.kick_step_equivalent = 10;
this.doKick = function() {
for (var i = 0; i < this.kick_step_equivalent; i++) {
this.doStep();
}
}
}
Boot.prototype = new BasicShoe();
function SteelTippedBoot {
this.max_steps = 175000;
this.kick_step_equivalent = 0;
}
SteelTippedBoot.prototype = new Boot();

Erroneous behavior of local variables in closures

I am stuck at the following code. At first I'll describe the use-case: The function "addPreset" gets called with an instance of ColorGradient. When calling this.listController.addItem(...) a callback function named onSelect ist supplied, which gets called everytime the onSelect-event on the listController-item is triggered. What I wanted to do is wrapping the call to GLab.ColorSlider.applyColorGradient(...) into a new closure, so that the assigned value of addPreset's "cg" argument"* will be "caught" inside it. But it doesn't work.
PROBLEM: Now everytime addPreset is called, the value of cg (being passed with a call) will override all values that bad been assigned before. However, this.presetList holds always correct values (the ones I expected to be caught inside the closure-function. Even inserting an anonymous function for breaking the scope doesn't help.
Please help me. :-)
Thanks, so far
function addPreset(cg) {
if (!(cg instanceof ColorGradient)) {
throw new TypeError("PresetManager: Cannot add preset; invalid arguments received");
}
var newIndex = this.listController.addItem(cg.getName(), {
onSelect: (function(cg2) {
return function() {
// addPreset's scope should now be broken
GLab.ColorSlider.applyColorGradient(cg2);
console.log(cg2);
}
})(cg)
});
this.presetList[newIndex] = cg;
}
#bobince: of course you can.
the code snippet above is part of PresetManager.js and the listController is an instance of the class ListWrapper.js
http://code.assembla.com/kpg/subversion/nodes/GradientLab/lib-js/PresetManager.js
http://code.assembla.com/kpg/subversion/nodes/GradientLab/lib-js/ListWrapper.js
#Matt: cg is an instance of ColorGradient. A custom class of myself. Further more, it is assured, that always "valid" values are passed in as cg. (When you'd have a few minutes you can download the whole assembla repo as zip-archive. Unzip and test in FF > 3.5 with Firebug console enabled.)

Answer can be found in this question: Doesn't JavaScript support closures with local variables?

Someone please correct me if I am wrong, as I am still fairly new to JavaScript closures and scope. But it would seem to me that the wrapping anonymous function you have is simply there to provide a proper scoped variable/closure for the function it is returning. Could this be simplified as such?
function addPreset(cg) {
if (!(cg instanceof ColorGradient)) {
throw new TypeError("PresetManager: Cannot add preset; invalid arguments received");
}
var closured = cg;
var newIndex = this.listController.addItem(cg.getName(), {
onSelect: function() {
// addPreset's scope should now be broken
GLab.ColorSlider.applyColorGradient(closured);
console.log(closured);
}
});
this.presetList[newIndex] = cg;
}

Just want to tell you, that I finally solved my problem by myself. It cost me almost 2 days (in the sparetime) to puzzling it out, but I think its worth that. At least my code remained elegant and I definitely got the whole thing with closures. Let's have a look:
My faulty code
Part 1 of 2:
function addPreset(cg) {
if (!(cg instanceof ColorGradient)) {
throw new TypeError("PresetManager: blablabla");
}
// calls the function in Part 2
var newIndex = this.listController.addItem(cg.getName(), {
onSelect: (function(cg2) {
return function() {
// addPreset's scope should now be broken
GLab.ColorSlider.applyColorGradient(cg2);
console.log(cg2);
}
})(cg)
});
this.presetList[newIndex] = cg;
}
Part 2 of 2:
// The method being called by this.listController.addItem(..)
function addItem(caption, args) {
var _this = this,
currIndex,
id,
newItem
itemSelectCb = (!!args && typeof args.onSelect == "function") ?
args.onSelect :
undefined;
currIndex = this.numOfItems;
id = this.ITEM_ID_PREFIX + currIndex;
newItem = this.$itemTemplate
.clone()
.text(caption)
.attr("id", id)
.bind("click", function(e) {
e.stopPropagation();
if (typeof itemSelectCb != "undefined") {
itemSelectCb();
}
_this._onSelect($(".ListWrapperItem").index(this));
})
.appendTo(this.$container);
this.numOfItems = $("." + this.DEFAULT_ITEM_CLASS, this.$container).length;
return currIndex;
}
The fixed code
The bug was in Part 2; when calld jQuery's bind-method for adding an click-event-listener I used an anonymous function (= new closure), but referenced itemSelectCb inside; so the anonymous function's scope stayed "connected" to the one of addItem. Everytime I called addItem, an other value were assigned toitemSelectCb what lead to the unknown sideeffect, that all references to itemSelect inside previously created anonymous functions are pointing to that value. What meant, that the last assigned value, had been used by all anonymous function.
To "break" the scope, all I had to do was to modify the lines of Part 2 where the event-handler for jQuery's bind was created. The fixed code looks then like this:
function addItem(caption, args) {
var _this = this,
currIndex,
id,
newItem
itemSelectCb = (!!args && typeof args.onSelect == "function") ?
args.onSelect :
undefined;
currIndex = this.numOfItems;
id = this.ITEM_ID_PREFIX + currIndex;
newItem = this.$itemTemplate
.clone()
.text(caption)
.attr("id", id)
.bind("click", (function(itemSelectCb) {
return function(e) {
e.stopPropagation();
if (typeof itemSelectCb != "undefined") {
itemSelectCb();
}
_this._onSelect($(".ListWrapperItem").index(this));
}
})(itemSelectCb))
.appendTo(this.$container);
this.numOfItems = $("." + this.DEFAULT_ITEM_CLASS, this.$container).length;
return currIndex;
}