JavaScript Fundamentals: Development for Absolute Beginners

By: Bob Tabor

Download the entire series source code here.

This course is divided in 21 parts:

1. Series Introduction
2. Writing your First JavaScript Application
3. Dissecting the First JavaScript Application You Wrote
4. Writing JavaScript in Visual Web Developer Express Edition
5. JavaScript Variables, Types, Operators, and Expressions
6. Conditional Logic in JavaScript
7. JavaScript Functions
8. JavaScript Arrays
9. Looping Statements in JavaScript
10. Understanding Function versus Global Scope
11. Working with External JavaScript Files
12. Organizing and Simplifying JavaScript with Object Literals
13. Understanding the Document Object Model
14. Getting Started with jQuery
15. jQuery Selectors
16. jQuery Events
17. Installing and Utilizing jQuery Plugins
18. Unobtrusive JavaScript
19. Using jQuery to Retrieve JSON via AJAX
20. Fundamentals of JavaScript Closures
21. Series Wrap-Up

URL: http://channel9.msdn.com/Series/Javascript-Fundamentals-Development-for-Absolute-Beginners

Source: Channel 9

CSS3 Transitions

With CSS3, we can add an effect when changing from one style to another, without using Flash animations or JavaScripts.
CSS3 transitions are effects that let an element gradually change from one style to another.

Shorthand:
transition: property_name duration timing_function delay;

To do this, you must specify two things:

• Specify the CSS property you want to add an effect to
• Specify the duration of the effect

Transition effect on the width property, duration: 2 seconds:

.moduleDefault {
transition: width 2s;
-moz-transition: width 2s; /* Firefox 4 and above */
-webkit-transition: width 2s; /* Safari and Chrome */
-o-transition: width 2s; /* Opera */
}

Note: If the duration is not specified, the transition will have no effect, because default value is 0.

The effect will start when the specified CSS property changes value. A typical CSS property change would be when a user mouse-over an element:

.moduleDefault:hover {
width: 300px;
}

Multiple changes:
You can also add a transitional effect for more than one style, add more properties, separated by commas.

Add effects on the width, height, and the transformation:

div
{
transition: width 2s, height 2s, transform 2s;
-moz-transition: width 2s, height 2s, -moz-transform 2s;
-webkit-transition: width 2s, height 2s, -webkit-transform 2s;
-o-transition: width 2s, height 2s,-o-transform 2s;
}

Note: These properties are not supported in IE

Boilerplate CSS Media Queries

Media Queries are now becoming quite common practice in web design. They allow you to change the CSS of the different elements on your web page depending on the size of the screen the visitor currently can see.

Below is a media query boilerplate you can use to change the design of your depending on if the user is using an iPad,iPhone or other smart phones. This snippet even allows you to change the design if the device is landscape or portrait.

/* Smartphones (portrait and landscape) ———– */
@media only screen
and (min-device-width : 320px)
and (max-device-width : 480px) {
/* Styles */
}

/* Smartphones (landscape) ———– */
@media only screen
and (min-width : 321px) {
/* Styles */
}

/* Smartphones (portrait) ———– */
@media only screen
and (max-width : 320px) {
/* Styles */
}

/* iPads (portrait and landscape) ———– */
@media only screen
and (min-device-width : 768px)
and (max-device-width : 1024px) {
/* Styles */
}

/* iPads (landscape) ———– */
@media only screen
and (min-device-width : 768px)
and (max-device-width : 1024px)
and (orientation : landscape) {
/* Styles */
}

/* iPads (portrait) ———– */
@media only screen
and (min-device-width : 768px)
and (max-device-width : 1024px)
and (orientation : portrait) {
/* Styles */
}

/* Desktops and laptops ———– */
@media only screen
and (min-width : 1224px) {
/* Styles */
}

/* Large screens ———– */
@media only screen
and (min-width : 1824px) {
/* Styles */
}

/* iPhone 4 ———– */
@media
only screen and (-webkit-min-device-pixel-ratio : 1.5),
only screen and (min-device-pixel-ratio : 1.5) {
/* Styles */
}

CSS3 – Substring matching attribute selectors

[att^=val] : Represents an element with the att attribute whose value begins with the prefix “val”.

[att$=val] : Represents an element with the att attribute whose value ends with the suffix “val”.

[att*=val] : Represents an element with the att attribute whose value contains at least one instance of the substring “val”.

This whole group of selectors is new, and the selectors in it let developers match substrings in the value of an attribute.

Assume that we have an HTML document that contains the following markup structure:
<div id=”nav-primary”></div>
<div id=”content-primary”></div>
<div id=”content-secondary”></div>
<div id=”tertiary-content”></div>
<div id=”nav-secondary”></div>

By using the substring matching attribute selectors we can target combinations of these structural parts of the document.

The following rule will set the background colour of all div elements whose id begins with “nav”:
div[id^=”nav”] { background:#ff0; }

In this case the selector will match div#nav-primary and div#nav-secondary.

To target the div elements whose id ends with “primary”, we could use the following rule:
div[id$=”primary”] { background:#ff0; }

This time the selector will match div#nav-primary and div#content-primary.

The following rule will apply to all div elements whose id contain the substring “content”:
div[id*=”content”] { background:#ff0; }

The elements that will be affected by this rule are div#content-primary, div#content-secondary, and div#tertiary-content.

The substring matching attribute selectors are all fully supported by the latest versions of Mozilla, Chrome, Firefox, Safari and Opera.

Reference: http://www.456bereastreet.com/archive/200601/css_3_selectors_explained/

JSON Object with integer values as key attributes

Using JSON object selection to paint the output based on descending key values.

JSON Object:

var popularObj= {
“89”:”animation”,
“71”:”apple”,
“64”:”barbara beery”,
“48”:”video”,
“39”:”cheese sticks”,
“29”:”games”,
“28”:”bbq pork sticks”,
“27”:”asian chicken tenders”,
“25”:”bake”,
“24”:”banana”
};

Problem:
The requirement was to paint only the values in descending order as they are the popular searches within the website. Whether we use for in loop or jquery each construct which does the same thing if the variable is an object, our results were varying across browsers namely Google chrome. The reason being in chrome, the key values were seen as array index instead of object key properties. The key values here were treated as indexes (integer indexes) and were painted in reverse order.

In Firefox and IE, we will get

“animation apple barbara beery video cheese sticks games bbq pork sticks asian chicken tenders bake banana”

and in chrome

“banana bake asian chicken tenders bbq pork sticks games cheese sticks video barbara beery apple animation”

Solution:
Convert the object into array, reverse it for chrome browser and then the finally load the dom object.

Note: In case the key was a text then the order of rendering is same across the browsers.