por Mike Ton hace 11 años
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semicolon insertion
scope
function scoped, not block scope
javascript
declare all variables at the top of each function
C
declare variable at site of first use
global variables
window.foo = value
window is global object of web browsers
add to property of global object
var foo = value;
var statement outside of any function
foo = value
implied global
use variable without declaring it
returns unique id
clearTimeout(id);
clearInterval(id);
var id = setInterval(fn, delay);
var id = setTimeout(fn, delay);
notes
never interrupt another currently running timer
browser object
Closure
An inner function enjoys that context even after the parent functions have returned
The context of an inner function includes the scope of the outer function
tip
declare all function before using
declare variables at top of function
invocation
recursion
quicksort
when a function calls itself
parameters
arguments
extra parameters placed into argument collection
read only structure; wise
array like, but not exactly
this
key to prototypal inheritance
allows a single function object instance to service many functions
contains reference to the object of invocation
return
all functions return something; "undefined" if not specifiec
statement
function foo( ) {};
can't put in if statement because of variable hoisting
relaxes the req that functions should be declared before usage; sloppy
moved to the top of the scope in which it's defined
requires name
expression
var foo = function foo( ) {};
preferable
makes it clear that functions are values
Release
AddRef
QueryInterface
A type library provides a common data format or interchange mechanism for describing the methods, attributes, parameters, and interfaces of a component. By establishing a common format, the same interfaces can be described across multiple platforms and multiple programming languages. This is useful for supporting a generic marshalling or proxy mechanism. Using the type info, a program can determine every parameter of any given method or attribute on some interface. With this knowledge, it can move data back and forth between the interface and some other environment. That other environment can be a scripting engine or a proxy mechanism for crossing thread, process, or network boundaries. In the case of a scripting engine, this is how a component gets defined in the scripting environment so that scripted code can invoke methods on a component's interface. XPConnect is an additional layer built on top of XPCOM that can marshal an XPCOM interface into the JavaScript engine by reading an XPCOM type library file. XPConnect also allows XPCOM components to be written entirely in JavaScript so you can have C++ code call a JS component, or use JS to load and manipulate a compiled C++ component. In addition to JavaScript, the Python language has been added as another scripting alternative using a mechanism similar to XPConnect.
You'll need to understand the difficult component topic of aggregation. Aggregation is a means for placing a component inside another larger component where the larger component delegates the responsibility of some of its interfaces to the internal component. This is nothing more than information hiding, which is one of the tenets of object-oriented programming. The issue of aggregation arises from the fact that all XPCOM interfaces must include the QueryInterface method. This means that your code, when using a component, has the ability to switch from one interface to another. This creates a problem when trying to write a new component that extends another, existing component. The QueryInterface method on the pre-existing component must somehow be able to respond to requests for new, additional interfaces introduced by the new derived component without any prior knowledge of the new code. If that sounds a bit wicked, it is.
access components in another
machine
process
<html>
<head>
<title>Mike is damn cool</title>
</head>
<body>
<svg mt_Datagjxmlns='http://www.w3.org/2000/svg'>
<path d="M 200,200 l 150,0 a150,150 0 0,0 -37,-97 z" fill="red" stroke="black" stroke-width="2" stroke-linejoin="round" />
</svg>
</body>
</html>
linejoin
width
color
arc
quadratic
S (x2 y2 x y)
C (x1 y1 x2 y2 x y)
T (x y)
Q (x1 y1 x y)
elliptical
A (rx ry x-axis-rotation large-arc sweep x y )
line
vertical
V (y)
horizontal
H (x)
L (x y)
move
rel
m (x y)
abs
M (x y)
framework
skeleton.css
base.css
content
layout.css
tag
.getElementbyTagName('body')
=document.body
id
.getElementById('name')
.childNodes[0]
sibling
.nextSibling
.previousSibling
last
.lastChild
=childNodes.length
1st
.firstChild
=.childNodes[0]
alt
.childNodes
.item(0)
.parentNode
TreeWalker
hiearchy
NodeIterator
content; flattened
elements
inline
block
Screen
h
768
w
make images less than
760
800
1024
length of scroll bar
40
984
size="num"
width="pixel/percentage"
<a> == anchor?
href="#"
on same page : different section/element/div
href=""
url link
type
file
upload
dropdown
checkbox
radio
text
area
field
action
URI
file:
mailto:
ftp:
http:
event
onsubmit = "javascript function"
submit button
method
post
storing, updating, e-mail, order a product
get
retrieve data
media
Flash
Function
Data
data
put table near graph
search engines can't
off
w/h = size of image
alt text describing image
text content
vector
SVG
pixel
png, gif, jpg
layout
table
JavaScript
event handling
mode
trickling
Wrong. Outdated Netscape 4 model avoid
Raphael
bubbling
event is given to target, then parent and on up until handled or canceled
node["on" + type] = f;
node.onclick = f;
non inline version
Netscape, works every where
put at bottom, pages will wait for script to load and execute
library
Jquery
plugin
User Interface
slider, controls, accordion...etc
Ajax
loading content from pages and dealing with JSON data
Effects
basic animations: moving, hiding/showing objects
Dom Events and helper functions
Manipulation and CSS
functions for editing and changing doc content
Selection and traversal
finding and navigating document contents
CSS
*(all elements on the page)
tag#id.className
tag.className
.className
#identifier
tagname
Core function and utility