Develop Reference

Pass Component Name as Argument and then attach method (not working?)

Maybe I'm not using the right terms/names for my searches but I have not been able to find anything on this topic. I would have thought this would be an easy thing to find. What I'm doing is passing a component name to a function and then trying to use the component's name by attaching a method to it. I have confirmed (via Dev Tools) that the name is correctly being passed but when I use the variable and attach the method the specific request does not work. If I 'hard-code' the exact component name to the method it works perfectly. This makes me think the (various) ways I've been trying to attach the method to the variable name is incorrect (see various attempts below). Can you offer some direction here? Thank you.
Passing to Function ...
const grid_name = "grid_GroupA";
console.log(grid_name); // Shows grid_GroupA
msg_max(newItem, grid_name);
Function (only listing relevant parts)
function msg_max(newItem, grid_target) {
console.log(grid_target); // Shows grid_GroupA
// grid_GroupA.data.add(newItem); // This works ...
// grid_target.data.add(newItem); // This does not work
// (grid_target).data.add(newItem); // This does not work
// [grid_target].data.add(newItem); // This does not work
// grid_target + '.data.add(newItem)'; // This does not work
Thank you ...
Edit ...
In my attempt to provide detail I hope I haven't confused the issue.
In essence, my question is if I can type this exact string
grid_GroupA.data.add(newItem);
and it works for my function, how can I place a variable with the exact string "grid_GroupA" in front of ".data.add(newItem);" and have it seen the same as the line of code that works? Maybe my lack of knowledge here is getting in the way but isn't the line of code that works just a string that is then used to 'find' the object? So, if that assumption is correct, how do I create that same string with the variable? If my assumption is wrong I am a willing learner so I will be all ears. Thank you.

I do not see how grid_target is an object. You are passing grid_name(which is a string) to the function, so grid_target will have no data property, because string doesn't have such a member.
P.S. snake_case is bad option for JavaScript, consider using cameCase instead

Conditional data structure (object) access

I have a set of JavaScript functions that handle certain objects. All these objects have the following flexibility:
Fields can be accessed like this: data[prop][sub-prop][etc.], OR
Like this (with a type sub-structure): data[TYPE][prop][sub-prop][etc.].
The object is accessed in many places, and the condition (let's call it is_mixed) is relevant everywhere.
I thought of the following alternatives:
Always access data like this: (is_mixed ? data[TYPE] : data)[prop][sub-prop][etc.]
Have a function called getData and always access data like this: getData()[prop][sub-prop][etc.].
The function code would be:
function getData() { return is_mixed ? data[TYPE] : data; }
Run the following on every new input: if (is_mixed) { data = data[TYPE]; }
It seems to me that options 2 and 3 might be copying the object data (which might be big) and performance is important here (I didn't find the literature to support this guess), but option 1 will make the code big and ugly.
Is there a better option? What's the best way to acheive this in terms of performance, code quality and basically best practices?

It seems to me that options 2 and 3 might be copying the JSON content
No, they won't. They both just copy an object reference, which is quick and cheap (like copying a boolean). #2 is of course slightly slower, since it's a function call, but if it's used a lot, any decent JavaScript engine will inline the function anyway, giving you the benefit of modularity at the source level. (It can take thousands of calls to the function in a shortish period of time to make that kick in, though; e.g., a modern engine only bothers with optimization when it looks likely to matter.)

Strange javascript behaviour - error unless 'classes' are defined in correct order

I have a very strange problem with javascript and easel js.
I am using the easel.js library and am already fairly far into the construction of a project using it.
I am attempting to have a 'class' (I know they aren't technically classes in javascript but I will use this terminology for lack of a better word) inherit the Shape class from easel js, and then have another class inherit that. So it would be something like this:
easeljs.Shape --> MenuButton --> BuildingButton
The code I am using looks like this:
BuildingButton.prototype = Object.create(MenuButton.prototype);
BuildingButton.prototype.constructor = BuildingButton;
function BuildingButton(){
MenuButton.call(this);
}
MenuButton.prototype = Object.create(createjs.Shape.prototype);
MenuButton.prototype.constructor = MenuButton;
function MenuButton(){
createjs.Shape.call(this);
}
The problem is that I get the following error with this code:
Uncaught TypeError: undefined is not a function
easeljs-0.7.1.combined.js:8439
(line 8439 is pointing to the initialize() function in the Shape() constructor).
now here's the strange thing. If I change the order of the definitions so that the sub class is defined second and not first, it works fine!
MenuButton.prototype = Object.create(createjs.Shape.prototype);
MenuButton.prototype.constructor = MenuButton;
function MenuButton(){
createjs.Shape.call(this);
}
BuildingButton.prototype = Object.create(MenuButton.prototype);
BuildingButton.prototype.constructor = BuildingButton;
function BuildingButton(){
MenuButton.call(this);
}
This is very confusing as I can't seem to figure out why on earth this is happening. I could just make sure I define them in the correct order and leave it be, but I have all my 'classes' in different source files which are then strung together by grunt, which does so alphabetically.
Also, I feel like I may have a big gap in my knowledge of javascript (or maybe easel.js I'm not sure what exactly is causing this behaviour).
Thanks in advance for your help and I hope the question makes sense!

MenuButton.prototype = Object.create(createjs.Shape.prototype);
…
BuildingButton.prototype = Object.create(MenuButton.prototype);
These two statements have a clear dependency and need to be executed in the correct order (for the function declarations the order is irrelevant if placed in the same scope/file, but if in different files they need to be loaded in the correct order obviously).
I have all my 'classes' in different source files which are then strung together by grunt, which does so alphabetically
That's not a good idea. You should use some build tool/script that allows the declaration of dependencies.

Read this to clear things out: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Inheritance_and_the_prototype_chain
In first example you try to inherit from nothing, since MenuButton.prototype is not yet defined. To make it work just add MenuButton.prototype = new createjs.Shape.prototype(instead of Object.create() wich shouldn't be used anymore) to instantiate it first before you can you use it. Your first code is like you are willing to eat a banana before having one.

EmberJS - Adding a binding after creation of object

I am trying to bind a property of an object to a property that's bound in an ArrayController. I want all of this to occur after the object has already been created and added to the ArrayController.
Here is a fiddle with a simplified example of what I'm trying to achieve.
I am wondering if I'm having problems with scope - I've already tried to bind to the global path (i.e. 'App.objectTwoController.objectOne.param3') to set the binding to. I've also tried to bind directly to the objectOneController (which is not what I want to do, but tried it just to see if it worked) and that still didn't work.
Any ideas on what I'm doing incorrectly? Thanks in advance for taking the time to look at this post.

So in the example below (I simplified it a little bit, but same principles apply)... The method below ends up looking for "objectOne" on "objectTwo" instead of on the "objectTwoController".
var objectTwoController: Em.Object.create({
objectOneBinding: 'App.objectOne',
objectTwoBinding: 'App.objectTwo',
_onSomething: function() {
var objectTwo = this.get('objectTwo');
objectTwo.bind('param2', Em.Binding.from('objectOne.param3'));
}.observes('something')
});
The problem is that you can't bind between two none relative objects. If you look in the "connect" method in ember you will see that it only takes one reference object (this) in which to observe both paths (this is true for 9.8.1 from your example and the ember-pre-1.0 release).
You have few options (that I can think of at least).
First: You can tell the objects about each other and in turn the relative paths will start working. This will actually give "objectTwo" an object to reference when binding paths.
....
objectTwo.set('objectOne', this.get('objectOne');
....
Second: You could add your own observer/computed property that will just keep the two in sync (but it is a little more verbose). You might be able to pull off something really slick but it maybe difficult. Even go so far as writing your own binding (like Transforms) to allow you to bind two non-related objects as long as you have paths to both.
_param3: function(){
this.setPath('objectTwo.param2', this.getPath('objectOne.param3');
}.observes('objectOne.param3')
You can make these dynamically and not need to pre-define them...
Third: Simply make them global paths; "App.objectOneController.content.param3" should work as your binding "_from" path (but not sure how much this helps you in your real application, because with larger applications I personally don't like everything global).
EDIT: When setting the full paths. Make sure you wait until end of the current cycle before fetching the value because bindings don't always update until everything is flushed. Meaning, your alert message needs to be wrapped in Ember.run.next or you will not see the change.

Compound Javascript Elements

I've got this page I'm doing some tests in Javascript and jQuery: JS Tests
I've got a few questions on how to create, not sure if this is right term, but compound controls via Javascript. In something like Flash, you'd create the Object class, have the getters and setters, draw your images, etc. In JS, it seems to be a very different thought process. My main question is How do you create multiple elements with getters and setters to be rendered, filtered, and interacted with in Javascript?
The main code regarding this example sits with:
var html = (function(){
// var FRAG = $(document.createDocumentFragment());
htmlBox = $(document.createElement("div"));
var eTitle = $(document.createElement("h4"));
var ePrice = $(document.createElement("p"));
// set class first
htmlBox.addClass("box")
htmlBox.css({
backgroundColor : color
})
// set text values
eTitle.text(title);
ePrice.text("$" + price);
htmlBox.append(eTitle)
htmlBox.append(ePrice)
return htmlBox;
})();
... inside the Box() class. If someone could take a look at the source and let me know what isn't quite right, that'd be great.
EDIT
Here's the final result for this example. Some logistics to work out, but what I'm after.
http://geerswitch.in/tests/obj/
As for the jQuery creating nodes, the built in JS version works fine for this, and some research on Google shows that the non-jquery way is faster in most cases anyway (and looks worse, imo)

You're doing it almost right. You've created a Box class to represent your higher-order UI element, you're instantiating it for each element, and your main program is manipulating the elements through its interface. The only thing you're missing is the split between the public interface and the private implementation. There's nothing to prevent me from doing myBox.price += 10 right now, even though the Box interface clearly implies that price should be set at construction and never modified.
JavaScript doesn't have visibility modifiers like "private" and "public", but you can create the same effect yourself. Check out Douglas Crockford's explanation for the details. Crockford is an opinionated genius when it comes to JavaScript, and he's the brains behind JSLint and JSON.