Showing posts with label function expressions. Show all posts
Showing posts with label function expressions. Show all posts

Wednesday, April 2, 2014

StarShine - 0.1.0 API Finalized, an App Architecture Tutorial, and Factory Inheritence



Here is the presentation on how to get started on using StarShine.

I'm going to demonstrate now how to actually make an app structured on top of StarShine.


This _eventify method will turn the private namespace of your module into an event emitter. This is useful for many things, but mostly it's a building block for an event emitter Factory. In order to expose the event factory, we simply return this; to expose the methods to the object. Finally, we wrap it in a StarShine factory. Here are some rules to remember.
  1. If the parts you create should remain private, create a closure.
  2. If the parts you create should only be exposed and the rest of your closures don't rely on it, create a compound factory
  3. If the parts you create should be BOTH, create a factory and create an instance in your closure
In this case, I want the event emitter to be public AND private. Option three is our target.


Of course, if you wanted events to be private (and therefore not exposed,) simply include the original function that created the event emitter in the first place. You don't even need the _exposeThis function.


Finally, if I want the methods to simply be exposed without referenced internally, I can do factory re-use.


Moving on, we should create a couple of closures that define different portions of our application. I'm going to look for anything with a [data-user-control-1] attribute on my dom and put a link inside of it.


This is a lot of code to read, so take your time and re-read it.

On the highest level, we define a process. Inside this process, we define a factory for creating a dom fragment and inject it into the container AND the private namespace for later use inside of the _createFragment function.

Then we create an anchor tag using the terrible dom api (encapsulated and transparent to the API consumer!) and append it to the container defined already.

Then we add a click listener to the anchor in a separate process that triggers a global APP event. The this in the parent closure is a reference to the event emitter exposed by our app.

We define an API for the control that can be consumed by the app and anyone who has access to see the UserControl. I put a remove function into the definition of a "UserControl1" as an example.

Finally, I add an event listener to the app to listen for UserControlClick events and remove the anchor from the DOM.

If you define your Application in terms of functions, suddenly everything is modularized and is much easier to maintain. Embrace the "encapsulate and forget about it" principle because you are making building blocks and tools.

The following example is a good place to start for your app.


Experiment and make the code work for you.

Now, onto factory inheritence (as promised!)


If you must accept different parameters, or some kind of state needs to be shared between the factories, maybe it would be best to make the combined factories actual private children of the parent factory. Each factory should be a unit or an encapsulated building block designed to operate all by itself.

Monday, February 24, 2014

SnowBlower and Object Composition


I'm going to talk about this "library" and why it's very useful. It takes a lot of the compositional techniques of objects and makes it really fun.

Here's an example of how to use SnowBlower.


It takes all the functions and objects that you pass to it, and either executes it in the context of your new object, or mixes it into your new object. If you need polyfills for your environment, just define Array.prototype.reduce, Object.create, and replace the Object.prototype.hasOwnProperty function to reflect your environment.

It's designed to be small and SnowBlower assumes you have all the pieces and closures that define your object up front. If you need to compose factories, you can just create a function that does it for you.


This is a DRY method of reusing functions you have already defined to compose objects. The sky is the limit! Just thought I would share this compositional technique with you.

~function(){console.log('josh')}();

Friday, January 3, 2014

Best Practices Can Change

Spend some time today learning the concepts behind technology coupling shown in this video:



If you'd like you can spend your time complaining about definitions on coupling, or you can accept your new JSX overlords. Or maybe you should just accept that maybe your practices aren't best.

So many feels


For a long time I was victim of this myself, where I found myself writing the same code over and over again, just for the sake of consistency in my C# code. I always had the same business logic functions, calling the same functions on a separate class, yet getting similar results repeatedly, and coupling myself into a corner. I didn't see it at the time, but I was making a total mess of my code!

I found myself trying to implement interfaces on objects I designed on only two classes, with the intention of calling it just once. I found myself having to maintain my object definitions in (I counted it) 25 different places when I had to add a column on the SQL table. Sure, the procedures and parameters changed my definitions, and that part was good, but for the sake of consistency, I wrote all the lines over and over again.

This practice was the worst decision of my life.

What a total waste of my time!


I almost wished I could use LINQ to generate an array in a few lines of code instead of a ridiculous cluster of declarative parameters. (So I did, but that's totally beside the point.)

Making a Change Toward Maintainability and Fun


I actually decided enough was enough about 2 months ago when I started working on some generic Object Extension components. I was going to make C# do the overhead for me instead of relying on declarative stuff. Here are some of the reasons why:
  • My front end performance was based on form loading time and not submitting time, because my organization doesn't need realtime processing, they needed data entry
  • My code base was the size of a continent and I'm the only maintainer
  • Some of the things I wanted could simply Extend Object using Object Extension (More on this later)
  • I don't care about your feelings
That last one is a huge one. I don't care what you think, I know my code is easy to maintain and fun to work with. Here's some of the techniques I now use regularly.
  • Using a procedure to grab SQL Parameters dynamically
  • Using Object Method Extension to perform:
    • Reflection operations
    • Dynamic Column evaluation
    • Dynamic Object population
  • Creating ASP.NET MVC Web forms insanely fast using reflection
  • Make functional components, not structural components
In a sense, I made my C# environment more like JavaScript. There, I said it. I made C# do the JavaScript jig.

You're kidding right?


You know what happened to my code?

It shrunk in half. This code is much more maintainable, because I expressed it in terms of static functions instead of classes, objects, and data types. I practically ignored them (With the exception of the Nullable classes, I really like those.)

Here are some of the methods I implemented that now extend my objects:
  • Object.get(String PropertyName) (Returns Object.PropertyName if it exists)
  • Object.set(String PropertyName, Value) (returns Object and chains)
  • Object.propertyExists(String PropertyName) (returns Boolean)
  • new ReflectiveRecord(DbDataRecord myRecord) (returns an encapsulated DbDataRecord that does the following...)
  • ReflectiveRecord.populate(Object myObject) (Applies a convention that the Object you are populating has the Same Property Names/Column Names)
  • DataAccess.InsertDatabase(String ProcedureName, ParametersObject) (Grabs procedure definition from database and dynamically pulls values out of ParametersObject)

I've yet to work out casting a sql data row to a reflective data record, but there will be a time when I will call something like this...

...and I won't regret it. I won't regret it a single bit.

This kind of technology makes SELECT * FROM TABLE inside of a stored procedure actually look pretty appealing, instead of selecting a bunch of columns in an unmaintainable fashion.

In the end, I maintain my Business Objects in 2 places. Once on the database server, and once on the front end (or multiple times if I seperate out an Insert/Update object that functions differently with the same property signature.) The best part is that I can simply populate whatever object I want with my data results implicitly, with one line of code, in a repeatable fashion, and have it work in every environment as a side dll that I can include in my project.

Go home Classical Structure, you're drunk!


If you feel disgusted, mad, or think this is bad, you better have a really good reason why, because I haven't found a reason (except for maybe dealing with processor performance on a computationally expensive algorithm.) If you are using C# for something besides rendering a template and gathering your data, this clearly doesn't help you anyway. I like saving my company time and money, and it almost seems like a no brainer when dealing with a childish argument like: "Everyone is doing it."

That sounds like a drug deal to me.

~function(){console.log("Josh");}();

posted from Bloggeroid

Thursday, December 26, 2013

jshint is good, but...

Let's just be upfront here because I don't want to hurt peoples feelings on jshint (which is apparently known for hurting people's feelings.) I can say many things about jshint , and 99% of them are good. In fact, there are a LOT of good practices that jshint enforces that I think are absolutely invaluable. Yet, here I am really just annoyed with a bunch of these "Code errors." Let me give you some examples.

1. I'm a NodeJS developer working on a test suite, using SHOULD and MOCHA, and I use jshint to test and make sure I use good coding practices. Here's what happens:


Well SCREW YOU TOO. Look at all these unmeaningful errors. I mean, require is definitely defined. I shouldn't have to deal with the jshint output like this.

2. I'm working on a token reader for the front end.



What happened here? I expected an assignment and a falsy check to occur during a while loop, and I got this lame output. Sure it's scrutiny and you can easily rewrite it to something like this:


The question is "Why?". So some novice developer can come in and see what your code does faster? Chances are this small obscurity will teach the novice developer about javascript and the things you can do with it. Sure it's "cute" and silly, but is it really worth your time to change your coding style like this? Just document it.


See, that wasn't so hard. I'd rather teach the beginner the "rules" and then break them.

The following example kills me every time:


Expected a 'break' statement before 'default'.

What if I wanted it to bleed over into the cases and use spaghetti code? Apparently novice coders are too dumb to spend time and figure it out for themselves. Chances are if your code is more complicated, you wanted another statement anyway. Yet, what if the offending sample is simple? What if the code happens to be easier to write and read with the switch statement? That's a matter of your opinion and really the decision should be left up to you.

(It also told me console was not defined but that's arbitrary.)

Look, just make a decision for yourself and use jshint to let it find your bugs before you do. Just make sure you read the error and make a determination for yourself if it's worth "fixing."

I probably spend more time sifting through 'console' is not defined more often than I would personally like to.

~function(){console.log("Josh");}();

Monday, December 9, 2013

Prudent Object Inheritence (that isn't classical)

Don't even think about classes. I'm really just tired of them, and you should be too. Forever we have been chained to classical inheritance (which I admit is faster for compiled languages.) Yet, maybe it's time we broke free from our bonds of definition and un-define ourselves in a meaningful way.

Hello Inheritance


It is prudent that we remember that our world is not defined. No matter how much science we throw at it, no matter how much the book of definitions grows, there will always be unknown. Our code will never be able to match the vastness of our comprehension and definitions. Clearly there is never a way to get around the fact that computers live in a supremely deterministic world. For this reason, every program should be known as art.

The very first definition of art when googling [Definition of Art]:

"the expression or application of human creative skill and imagination, typically in a visual form such as painting or sculpture, producing works to be appreciated primarily for their beauty or emotional power."

We should remember that we actually make a living off of the fact that programmers take something defined and absolute to create something amorphous and functional. Programmers also take requirements and turn them into something displayed on a screen. This alone is remarkable. In the context of art, we are untypical, yet we try to produce works to be appreciated by their physical or tangible power, rather than their beauty or emotional power. (Or maybe you do?)

The Chains of Determinism and Convention over Configuration




Given the example, I show you inheritance that actually makes sense. When you inherit a simple interface in C#, things become more generic and happy. Do not confuse this for complicated inheritance chains that convolute your code. Applying an interface to multiple objects makes your code flow better and work with different definitions faster. These specific kinds of contracts are exactly what you need.

It also bodes us well to remember that javascript ascends beyond this need to define. It takes all the deterministic work out of your code. What you are stuck with are the conventions you use to define your work, and the configurations you provide to your client.

Why not instead of classes, think of your javascript code like you would a composer? The composer cares not about determinism. In fact, some composers would say their work leads them to the solution. The composer applies musical conventions and not configurations to define their pieces. In fact, most configurations are left up to the conductor who interprets the pieces created by the composer.

Even if you can define the notes used to compose a piece, it makes sense that those notes would mean something so much more!

What does this mean for you?


You are not a composer, (or maybe you are,) and thus, should act accordingly. Instead of relying on supreme indeterminism, rely on some convention in your code. Convention will make your code faster and smaller. Of course, definitely do type checking, but be willing to be flexible where you do it. Wherever your API interfaces with a developer, be flexible enough to call Object.prototype.toString.call(object) and really see what is going on. You may be accepting the input of another library (hopefully with the right conventions) but in complete honesty, you never know what you are going to get.

So throw in the towel, right?

HECK NO.


You should instead, play into javascript like you mean it.

Have the courage to do something like this:



Yeah. I totally went there.

The only adjustment you need to work with javascript is your attitude towards it. Javascript cannot be deterministic. So embrace it's functions and super generic objects, and enjoy your smaller (and somehow faster) code base.

You won't regret it.

Lastly, here is a sample of the stuff you can do with a very small (2kb minified) library that I wrote by hand.



This is the way object coding should be (minus the pyramid syntax that plagues the gist's version of callback hell.)

You define repeatable closures and mixin objects. Suddenly, you have a repeatable way to generate objects. Just don't forget that those pieces can be called directly like this:



Want to actually use it in your project? The command is simple (for node anyway:)



In functional health,
~function Josh(){}()

Friday, December 6, 2013

Classical Inheritance is dead and what you can do about it

There is nothing new in this blog post, but all of this is worth mentioning to everyone repeatedly. If javascript was meant to have classes, it would have had them in the first place. Instead we are stuck with the following clunky syntax and keywords to do type checking.



Instead you probably just wanted this.



Look at how simple that is! It's so much faster. Even to a beginner programmer, the hint that this.name may actually be the name property of the object literal.

Need to do instanceOf? Why not do something like this instead?



Seriously! There's so much less code. In fact, why not just  forget the whole "new" paradigm? Well, maybe not forget, but use it wisely. It also begs the question, how do you make objects repeatedly? Don't you need some kind of overhead? What about applying prototypes to already created objects? Or worse. What about multiple linear inheritance?

Your goal when making applications is get the banana. Not the gorilla, not the jungle, and not everything else. See the following video.

Perhaps it might be overstated that using stampit is quite useful. It is also very close at getting the banana. At 10kb I found that stampit was the correct solution on the back end where we control  the modules. Size doesn't matter on the back end. On the front end, it might be more like a fruit salad to a mobile phone. I also have nothing but respect for Eric's library, because it really showcases the fundamental units of object creation.

Could you perhaps have wanted something smaller? (Yeah it's a pretty shameless plug.)

After all, passing callbacks should be really terse.

We should always remember the few components that comprise our objects and functions: Properties, values, closures, functions, prototypes, and contexts.

Edit:
Don't forget to check out the npm registry for my library composer.js.

Monday, November 18, 2013

Canvas Clickable Regions - Demystified

Let's face it, canvas stuff is never terse and annoying. Creating buttons on a canvas is even harder. First you have to draw the button, change it's state, and other complicated things.

For instance, if the user pushes the mouse down on one clickable region, and drags it over to ANOTHER clickable region, the "click" event will still fire and (therefore) fire the second region's click event.

So what kinds of things do we actually need to figure this stuff out?

Well, for starters, let's demystify the mouse event positions.



This will give you a way to get the mouse location of any click event. So let's build our clickable region first.



Cache the canvas and draw an image...



..and the only things that are missing are the click events...



and put it all together!



The final product looks a bit like this, because you totally took the code and made it work for your project.. right? Get coding people!

In functional health,
Josh

Friday, November 15, 2013

Array forEach Synergy

Today I wanted to share another nice and small use case for the forEach loop for the intermediate/beginner javascript developer.



As a disclaimer, my code isn't perfect, it can be optimized, and my goal isn't give you snippets of code to steal. However, I do this to show you how to make your own javascript functions yourself. Take my code and tweak it, add some useful functions that may help you finish your project.

I hope my samples help grow and motivate you to strive and become a better programmer.

In functional health,
-Josh

Monday, November 11, 2013

Sharing: Self Invoked Object Literals

Some techniques aren't new or novel. They are just fun. This isn't really new, or novel either, but it's quite fun.

In fact, some people would probably criticize that it is essentially the same thing as an Immediately Invoked Functional Expression. There are some key differences here though. Take a look at the following code.

It's starting to look like the module pattern, but it creates an object and ships it via function baz to the variable foo with bar's prototype. Alas, the this keyword shows it's confusing head again, but look closely. "this" is the object literal itself.

Finally I'll leave you with a working example.

Sometimes, the "new" keyword is overrated when making objects anyway.

In functional health,
-Josh

Friday, November 8, 2013

Defining Plugin Architecture for Constructor Libraries

Even in a hypothetical world where objects are packaged into black boxes it would seem that convention and configuration butt heads repeatedly until developers are quite frustrated with their code. In the real world it's even more difficult to package up black boxes because the language architecture design is fundamentally flawed. (I'm looking at you Javascript global namespaces!)

So, I've personally set out to develop quick easy ways to make boxes that appear to be black boxes, but are highly configurable.

Here were some of the goals I had in mind for designing my personal plugin Architecture.

  1. Had to be easy!
  2. Had to be quick!
  3. Plugin Convention over configuration
  4. Boilerplate-able
  5. Should give access to constructor options to determine where the construction of the object goes
  6. Should provide a local scope for hidden variables relative to each object.

Here's a boilerplate you can use to create something like I'm describing.

I've a feeling we're not in the global namespace anymore.

If some of that code looks confusing to you, I suggest looking at the concept of functional expressions. They give you a "pseudo-blackbox" that can see the global namespace.

If you are good on closures, then we move on to the next step. Actually defining the code to make plugins work. Here's what I personally use:

This code is rather simplistic, but lets take a look a bit deeper to see the real beauty of it.

This little function right here is where ALL the magic happens. Let me show you an example of why this is "magic." Writing a plugin is very easy to do here.

Boom! Now you can call this:

As if that wasn't enough... let's go back and look at another example. A full on event emitter API.

Take some serious time to learn what just happened here. Each one of the functions created in that script are local to the object itself, because the plugin constructor code is called only once. This allows you to enclose private variables into a black box namespace. It's completely abstracted away to the developer behind the curtain.

Please pay no attention to the variables behind the functional expression.

In functional health,
-Josh