[CSS3 + HTML5] Modernizr

Modernizr is a library for detecting whether the user's browsers have certain features and based on the availability, we developers will trigger certain functions or styles. In this episode, we will take a simple slideshow and use both javascript and css3 to make the transitions based on features available with libraries such as yepnope and html5shiv. Most importantly, we will scratch the surface of what is graceful degradation and progressive enhancement.

If you use modren JS Framework like Angular, when comes to IE8, it will report error. And I believe, IE9 below will be abandoned, moderen web technology will no longer support IE9 below.

But it will still valuable to know how to handle css / javascript fallback on old bower.

1. installing modernizr

download the entire library from modernizr or cdnjs and put a <script> tag in the <head> of index.html. Open up the browser dev console to see some classes added to the <head> tag:

<html lang="en" style="" class=" js flexbox canvas canvastext webgl no-touch geolocation postmessage websqldatabase indexeddb hashchange history draganddrop websockets rgba hsla multiplebgs backgroundsize borderimage borderradius boxshadow textshadow opacity cssanimations csscolumns cssgradients cssreflections csstransforms csstransforms3d csstransitions fontface generatedcontent video audio localstorage sessionstorage webworkers applicationcache svg inlinesvg smil svgclippaths"><head>

2. feature detection

if a css property is not available:

.box{
  box-shadow: 0 0 10px 1px #666;
}
.no-boxshadow .box{
  border: 3px solid grey;
}

if a css property is available:

.box{
  border: 3px solid grey;
}
.boxshadow .box{
  box-shadow: 0 0 10px 1px #666;
}

html5 tags:
- include the option for html5shiv when generating the modernizr
- now semantic html5 tags are easily seen in older browser as well
- if the entire html5shiv library is not needed, then create the html5 element indivudally and put the javascript in the <head>tags
javascript fallback:
- for a javascript fallback, use yepnope.js - ensure it is part of the generated modernizr as well. Put the scripts in the <head>tag.

<script>
    yepnope({
        test : Modernizr.cssanimations,
        yep  : 'slides.css',
        nope : 'slides.js'
    });
</script>