Skip to main content

SASS Converts Zero Opacity 'rgba' To 'transparent'

I recently had a strange problem after updating SASS. I have a modal dialog with a semi-transparent overlay behind it. For modern browsers, I'm using a CSS transition from 

rgba(0,0,0,0)
to 
rgba(0,0,0,.5)

For older browsers (namely IE8), I'm using some JavaScript to apply the transparency and animate the transition. To make sure the background gets set correctly, I'm using the standard fallback strategy of defining the background as background: rgb(0,0,0); right before the rgba line.

This worked fine, until SASS optimized my code by changing 

background: rgba(0,0,0,0);
to 
background: transparent;

The reason? It's 2 characters shorter. Yes, we've now saved 2 bytes of easily compressible text in exchange for breaking my code.

Why did it break? Well, if you haven't already figured it out, normally a browser that doesn't support rgba will simply skip that property and move on. But transparent is supported. So now, instead of having a black background that I would later animate the opacity, I'm animating the opacity of a transparent background.

To fix this, I simply forced SASS to output the exact text I wanted. 

#{rgba(0,0,0,0);}
It's not ideal, and I probably could have changed my code so that I didn't have to be in this situation at all. But this was the quickest, most straightforward solution.

Labels:

Comments

Post a Comment

Popular posts from this blog

Flags vs Vendor Prefixes for Experimental CSS

Google recently announced that it will be switching Chrome's rendering engine to a fork of Webkit, called “Blink”. If you're interested, you can read their blog post about Blink . One of the changes we will be seeing in Blink, is the use of browser flags in place of vendor prefixes . What this means, is that rather than prefixing experimental CSS with -webkit-, -moz-, -ms-, -o-, -khtml-, etc.; We will be required to enable these attributes using a flag in the browser (like the ones currently at chrome://flags). If you ask me, both ways have their advantages and disadvantages. Though, in the end, I lean towards the flags over the vendor prefixes, and here's why: #1 Code Bloat On average, using CSS with vendor prefixes requires writing it 5 times . Every time you use it . #2 Future Friendly Eventually, prefixed code will be replaced by the unprefixed code. #3 Browser Dev Friendly Browsers tend to continue to support the prefixed code, even if it doesn...
Post a Comment
Read more

Element.focus() in IE9 running Jasmine tests with Karma

I recently udpated our Jasmine unit tests to run in Karma ; expanding our browser coverage, adding code coverage reports , and using fixtures for testing DOM manipulation . One of my tests kept failing in IE9, but only when I ran from the console. If I attempted to debug in the browser, everything passed. It turns out that IE9 (at least) needed a few ms to catch it's breath before correctly focusing on the starting element. To do this, I just added a 100ms delay before each test ran (Using Jasmine 2.3). beforeEach(function(done){ loadFixtures('myfixture.html'); // Setting focus in IE requires a delay to work correctly! setTimeout(function(){ done(); }, 100); });
Post a Comment
Read more

Get width and height of a remote image with VB .NET

The Problem I wanted to grab the width and height of an image that was on a remote server. I've done this with PHP, but never in .NET. The Solution I did a little digging and came across this code (slightly modified for my own purposes). Dim request As HttpWebRequest = DirectCast(WebRequest.Create(URL), HttpWebRequest) request.Method = "GET" request.Accept = "image/*" Dim response As HttpWebResponse = DirectCast(request.GetResponse(), HttpWebResponse) Dim s As Stream = response.GetResponseStream() Dim bmp As New Bitmap(s) Width = bmp.Width Height = bmp.Height
Post a Comment
Read more