How to preserve units with SASS computed variable? - sass

I try to create some relative font-size values that match "nearly" pixels sizes:
html { font-size: 62.5%; }
$font-10px: 1em/1.1em;
$font-11px: 1.1em/1.1em;
$font-12px: 12em/11em;
.x10 { font-size: $font-10px; }
.x11 { font-size: $font-11px; }
.x12 { font-size: $font-12px; }
However, the output of this sass snipet is:
.x10 {
font-size: 0.90909;
}
.x11 {
font-size: 1;
}
.x12 {
font-size: 1.09091;
}
As you can see, the unit (em) has been stripped.
This results in a incorrect value.
How should I declare my variables to contains the correct unit?

Dividing one length by another length always results in the unit being removed if the lengths are using the same units. So your options are:
Divide using one length and one integer: 1.1em / 1.1
Multiply the unit back on afterwards: 1.1em / 1.1em * 1em
Don't use division at all: 1em

Add PX to the end of your variable and surround the variable with #{ }. This is known as interpolation #{ } and treats the variable as plain css. Interpolation also helps to remove any spaces between the number and unit of measurement:
$base-font-size: 16;
body { font-size: (62.5% * base-font-size); }
$font-10px: 1em/1.1em;
$font-11px: 1.1em/1.1em;
$font-12px: 12em/11em;
.x10 { font-size: #{$font-10px}px; }
.x11 { font-size: #{$font-11px}px; }
.x12 { font-size: #{$font-12px}px; }
Result:
.x10 {
font-size: 0.90909px;
}
.x11 {
font-size: 1px;
}
.x12 {
font-size: 1.09091px;
}
Since you mentioned accessability in the SA talk, I recommend that you add one of the mixins in this blog post by Hugo Giraudel to your project to allow the use REM units while also providing backwards compatibility for older browsers.

Related

Sass manipulate with #content

Is it possible to manipulate with #content magic variable in SASS?
I would like to replace some stuff in here before output.
Or maybe can I fill some variable with it?
The conclusion is that, I want to make an mixin #important that create both versions. Important, and no-important.
Input
.test {
#include important {
color: red;
text-align: left;
}
}
Expected output
.test {
color: red;
text-align: left;
}
.test-i {
color: red !important;
text-align: left !important;
}
No, you can't. But I quickly wrote you a mixin to make it work. It doesn't accepts multiple properties (yet).
First Note: I changed the mixin it now does accept multiple properties. Here is the Codepen.
Second Note: I updated the mixin adding multiple properties does no longer compile to different classes for each property, instead you get two versions, one without the !important suffix and one with.
This is the mixin:
#function return($state) {
#return if($state == '', '', '-i');
}
#mixin loop($name, $items...) {
#each $item in $items / 2 {
#each $state in ('', '!important') {
$suffix: return($state);
.#{$name}#{$suffix} {
#for $i from 1 through (length($items) / 2) {
#{nth($items, ($i * 2) - 1)}: #{nth($items, ($i * 2))} #{$state};
}
}
}
}
}
This is how you include it:
// #include loop([classname], [property], [value]);
#include loop(whateverClassname, color, red);
This is what it compiles to:
.whateverClassname {
color: red ;
}
.whateverClassname-i {
color: red !important;
}
This is what it now compiles to, when you use multiple properties at once:
#include loop(whateverClassname, color, red, background-color, green, display, flex);
.whateverClassname {
color: red ;
background-color: green ;
display: flex ;
}
.whateverClassname-i {
color: red !important;
background-color: green !important;
display: flex !important;
}
Conclusion: it works as expected and does no longer bloat your CSS.
Hope I could help you at least a little ;-)

Using a sass variable in an #each loop

I'm trying to create a little overview for all the colors we use in our corporate identity. All our colors have been defined in _settings-colors.scss, and the only reason I need this bit of css is for the library, where the colors need to be listed.
What I have now is as follows:
$colors-brand: color-brand, color-brand-40, color-brand-60, color-brand-70;
.prfx-color {
display: block;
height: 5rem;
width: 100%;
#each $color in $colors-brand {
&--#{$color} {
background-color: #{'$'+$color};
&::after {
content: '$'+$color;
}
}
}
}
These color-brand variables are set in another file which I'm including in this scss file.
The code above outputs this:
.prfx-color {
display: block;
height: 5rem;
width: 100%;
}
.prfx-color--color-brand {
background: $color-brand;
}
.prfx-color--color-brand::after {
content: "$color-brand";
} [...etc]
What I'm after however, is this:
.prfx-color--color-brand {
background: #00ff11; // don't worry, brand is not actually this color
}
The problem I'm having is that the $color-brand variable isn't interpreted as a sass variable anymore, but is a literal value. I need the #hheexx that this variable refers to!
All the solutions I've found so far consist of using two lists, or a key-value pair. In my situation these variables have already been set once, and I want a solution where I don't want to have to manually edit the library if the colors change.
Is this at all possibe, or am I too greedy here?
And I realized I overcomplicated it. You don't need any extra functions because the #each is designed to work with maps and iterating over multiple values.
$cool: blue;
$mad: red;
$colors: (
cool: $cool,
mad: $mad
);
.prfx-color {
#each $key, $val in $colors {
&--#{$key} {
background-color: $val;
&::after { content: "$#{$key}"; }
}
}
}
You could use a map.
Here's a sassmeister playground for you.
$cool: blue;
$mad: red;
$colors: (
cool: $cool,
mad: $mad
);
.prfx-color {
#each $color in map-keys($colors) {
&--#{$color} {
background-color: map-get($colors, $color);
&::after { content: "$#{$color}"; }
}
}
}

Dividing percentage variable in Sass?

I have a variable which is a number and a % eg 10%. How can I use it as a value in my SASS but apply a division on it?
I have this:
$value: 0.1;
$value-percent: $value * 1%;
$value-from-50: (50 - $value) * 1%;
.test {
padding-left: $value-percent;
}
.test2 {
width: $value-from-50;
}
Which outputs this:
.test {
padding-left: 10%;
}
.test2 {
width: 40%;
}
What I now need to do is apply half of the value of $value-percent:
.test3 {
padding-left: $value-percent / 2;
}
So that I can output:
.test3 {
width: 5%;
}
Ive tried various combinations of that example code with normal and curly brackets. I can get the correct number of 10 outputted into the CSS but the % is always missing from it.
If your initial var isn't a percentage and is just a number you may need to try this:
.test {
padding-right: ($var / 2) + 0%
}
Which is better practice as it'll convert the value you pass it into what you're adding it to, in this case a percentage.

Is it possible to concatenate two siblings without parent in Sass?

What I want is concatenate two child inside the parent but without choosing the parent on output.
What I mean is here:
.parent {
.child {
color: green;
& + & {
margin-top: 6px;
}
}
}
On the output I have this:
.canvas-btn .canvas-btn__icon + .canvas-btn .canvas-btn__icon {margin-top: 6px;}
but if it's possible to make the next way without duplicating the code is Sass?
.canvas-btn .canvas-btn__icon + .canvas-btn__icon {margin-top: 6px;}
You need to use the parent selector (&) as a variable here and treat it like the list of lists that it is:
#function nest-adjacent-selector($sel) {
$new-sel: ();
#each $s in $sel {
$last: nth($s, -1);
$new-sel: append($new-sel, $s #{'+'} $last, comma);
}
#return $new-sel;
}
.parent {
.brother, .sister {
color: green;
#at-root #{nest-adjacent-selector(&)} {
margin-top: 6px;
}
}
}
Output:
.parent .brother, .parent .sister {
color: green;
}
.parent .brother + .brother, .parent .sister + .sister {
margin-top: 6px;
}
Note that this will not work if you're using certain versions of LibSass. For more information on how this works, see this question.

How do you remove units of measurement from a Sass mixin equation?

I've written a very simple Sass mixin for converting pixel values into rem values (see Jonathan Snook's article on the benefits of using rems). Here's the code:
// Mixin Code
$base_font_size: 10; // 10px
#mixin rem($key,$px) {
#{$key}: #{$px}px;
#{$key}: #{$px/$base_font_size}rem;
}
// Include syntax
p {
#include rem(font-size,14);
}
// Rendered CSS
p {
font-size: 14px;
font-size: 1.4rem;
}
This mixin works quite well, but I'm a bit unsatisfied with the include syntax for it. See, I would much rather pass a pixel value into the include statement instead of a simple number. This is a small detail, but it would add semantic meaning to the include statement that currently doesn't exist. Here's what I get when I try to pass a pixel value into the include statement:
// Include syntax
p {
#include rem(font-size,14px);
}
// Rendered CSS
p {
font-size: 14pxpx;
font-size: 1.4pxrem;
}
Once Sass sees a pixel value being passed into an equation, it outputs the 'px'. I want to strip that unit of measure out as if I were using parseFloat or parseInt in JavaScript. How does one do so inside of a Sass mixin?
Here is a function you could use. Based of Foundation global helper functions.
#function strip-unit($num) {
#return $num / ($num * 0 + 1);
}
Sample use:
... Removed for brevity ...
#mixin rem( $key: font-size, $val ) {
#{$key}: strip-unit( $val ) * 1px;
#{$key}: ( strip-unit( $val ) / $base-font-size ) * 1rem;
}
Removing units from a number is done by division, just like in Algebra.
$base-font-size: 10px;
$rem-ratio: $base-font-size / 1rem;
#mixin rem($key,$px) {
#{$key}: $px;
#{$key}: $px/$rem-ratio;
}
// Include syntax
p {
#include rem(font-size,14px);
}
// Rendered CSS
p {
font-size: 14px;
font-size: 1.4rem;
}
Units in Sass can be treated as in real math, so px/px/rem goes to just rem. Enjoy it!

Resources