Merge branch 'master' of github.com:cyberwizardinstitute/workshops

Author: James Halliday

javascript.markdown

@@ -1417,4 +1417,5 @@ http://nodeschool.io/#javascripting
 ---
 # links
 
-http://jsforcats.com/
+- [jsforcats.com](http://jsforcats.com/)
+- [learn more about function hoisting here](https://gist.github.com/maxogden/4bed247d9852de93c94c)

node_101.md

@@ -0,0 +1,120 @@
+# Node.js
+
+A computer program can run in many host environments.
+
+Programs run on desktops, tablets, small devices, smart devices.
+
+Some programs run across various operating systems; this is useful.
+
+This is possible because the language of your program has interpretters and compilers that work in a particular host environment.
+
+It's very environmental.
+
+Javascript programs run inside every browser tab.
+
+On billions of devices, across all operating systems.
+
+Node.js created an environment for running javascript outside of the browser as well.
+
+This allowed for many new kinds of applications to be written in Javascript, which previously worked only in the browser.
+
+Node.js was a very clever hack, and has become a invaluable tool for web developers.
+
+Node.js performs very well for what it was intended.  Node.js was intended for writing web server applications, the back-end.
+
+Node.js also performs well enough for many things it was never intended, because it made writing myriad various programs much less painful.
+
+This is entirely due to a large commnity of open source programmers, slowly chiseling at good forms, styles, and practices.
+
+Many of these would be codified into Node.js, and from there influence code writing for front-end apps.  
+
+And there is no doubt Node.js has set the bar for community backed open source development, as much as it sets a bar for high performance web apps.
+
+Perhaps best of all, Node.js allows the intrepid hacker to create full stack, web applications with a single language:  javascript.
+
+# Events
+
+EVENTS are an important concept for the javascript and Node.js programmer, as well as designers of interfaces, or machines with sesnors.
+
+What is an event?  Unlike many programming concepts, an event is exactly what you should expect.
+
+An event is when something happens.  
+
+Javascript is the language of the browser, and that includes user interactions--events.
+
+Therefor Javascript has always been event oriented.
+
+Node.js took this evented straight to the core, creating an event driven architecture, which turned out to be a brilliant idea.
+
+Almost everything is an event.
+
+A click, a key press, a scroll motion, are events.
+
+A connection, an update, an interval, are events.
+
+Some events can be broken down into several events.
+
+A button is pressed, is held, is released.
+
+A conncection is opened, is upgraded, is closed.
+
+Many programmers failed to realize this nature of javasctipt, because they wrote most of their code in another language, which did not emphesize events.
+
+The result are many confusing paradigms for wriring javasctipt programs, such as Model-View-Controller, or MVC.
+
+With Node.js, events are fundamental, the basis for all higher order constructs, most importantly STREAMS.
+
+A stream takes a pattern of events, and creates a flow out them.
+
+But how do you write a program that anticipates various events, and then does something with the potentially unknown consequences of these events, such as an error, or the receipt of arbitrary data?
+
+There is only one answer.
+
+You must write functions that listen for verious, specified events, and you must write functions that handle the result of the events, if and when they occur.
+
+The first kind is a "listener".
+
+The second is a CALLBACK.
+
+# Callbacks
+
+A CALLBACK is simply a function, no different than any other function, which is called upon an event.
+
+Most confusion about calbacks stems from confusion, or laziness, about javascipt functional syntax.
+
+Consider the following:
+
+```js
+event.on('update', function(data){
+  console.log(data)
+})
+```
+To the uninitiated, this may look like a pinata of inscruotable syntax.  
+
+A function is being called, which takes two arguments.  One argument is the string 'update', the next argument is a function.  This is confusing because that function is written out within the parenthesis of the function being called.
+
+Another way looks like this:
+```js
+var callback_Function = function(data){
+  console.log(data)
+}
+
+event.on('update', callback_Function)
+```
+
+Now you can see that the callback is a generic function, and event.on is a function being called() with two arguments, one of them a function.
+
+When an event fires that is an 'update',  call the supplied function, in this case 'callback_Function'.
+
+It is very common in javascript to supply a function as an argument, like in real life you might give directions "in the event" something occurs.
+
+Node.js is build around events.  This is because there is often some time between the initiation of a sequence, and it the events which are produced.
+
+Direct your program to open a file, and when the file is open, do something.
+
+so much for events and callbacks.
+
+
+
+
+