How to deprecate Sass pure variables? - sass

I have some Sass variables that I want to deprecate soon. How do I do it, without changing the implementation of it?
I want to allow the usage of variables below, but I want to show a message during the compilation step (whenever they are used), that the variables below are going to be deprecated. Is it possible? Also, can I display where the deprecated variable was used?
$screen-xs-min: 320px;
$screen-sm-min: 480px;
$screen-md-min: 768px;
$screen-lg-min: 992px;
$screen-xl-min: 1200px;
$screen-xs-max: ($screen-sm-min - 1);
$screen-sm-max: ($screen-md-min - 1);
$screen-md-max: ($screen-lg-min - 1);
$screen-lg-max: ($screen-xl-min - 1);

I was looking for the solution for this as well and created my own. Maybe this will help someone else.
#use "sass:list";
// The key is the deprecated variable, note the missing $. The value is the newly suggested one.
$deprecated: (
"font-size-h1": "$font-size-h1-clamp",
"font-size-h2": "$font-size-h2-clamp",
"font-size-h3": "$font-size-h3-clamp",
"font-size-h4": "$font-size-h4-clamp",
"font-size-medium": "$font-size-medium-clamp",
"font-size-large": "$font-size-large-clamp",
"font-size-extra-large": "$font-size-extra-large-clamp",
);
#each $variable in $deprecated {
#if variable-exists(list.nth($variable,1)) {
#warn "The scss variable $#{list.nth($variable,1)} is deprecated. Please use #{list.nth($variable,2)} instead.";
}
}

Related

Is it possible to load sass variables from file into a map?

I want to have a map of all bootstrap vars i'm using in sass.
$FULL_MAP = ("bootstrap": #include(bootstrap/_variables.scss)
To achieve this, do I have to manually rewrite the whole file?
I have ended up manually putting required vars into a map and then using themify mixing in order to apply vars from the map. The code is on github and this is the file that puts variables into the map
.custom-scope {
#import "~bootswatch/dist/cerulean/variables";
$cerulean: (
"primary":$primary,
"secondary":$secondary,
"success":$success,
"info":$info,
"warning":$warning,
"danger":$danger,
"light":$light,
"dark":$dark
);
$themes: map_merge($themes, ("cerulean": $cerulean)) !global;
}

How do I actually apply values from SASS List/Maps to elements?

I've inherited a project and it has a variable list/map in its scss file, which has:
$palette: (
success: #53a646,
warning: #faa41a,
alert: #ec5840,
);
I want to use one of these variables (warning) and apply it to an element. I've googled but have not been able to find a way to apply it.
I've seen examples like:
.warning-btn {
background-color: nth($palette, 2);
}
But this isn't working for me.
Would anyone know the correct way of applying the variable to an element?
change your code to the following
$palette: (
success: #53a646,
warning: #faa41a,
alert: #ec5840,
);
.warning-btn {
background-color:#{map-get($palette,warning)}
}
Hope it helps

Can someone explain this Sass For loop syntax - #{$i}

In the Sass docs, we have this:
#for $i from 1 through 3 {
.item-#{$i} { width: 2em * $i; }
}
I understand the loop. But I don't understand where in .item-#{$i} why the $i variable is encased in #{}? Why not just write $i?
I've looked around and can't find anywhere that explains this.
It's called Interpolation, and is needed when using a variable in a selector or property name. See http://sass-lang.com/documentation/file.SASS_REFERENCE.html#interpolation_

How do I access a specific element of a mapping?

I have the following mapping to contain all of the colours from my theme:
$_base-ocean:rgb(13,176,184);
$_base-hover:10%;
$themes: (
ocean: (
base: $_base-ocean,
hover: darken($_base-ocean, $_base-hover)
)
);
I know how to use an #each loop to get the key/value information from a mapping, but how can I directly access the value of a mapping without using a loop? I tried using square brackets like you would in other languages like JavaScript:
#each $name, $colors in $themes {
[data-page="home"] {
#slider-pagers{
a.#{$name} {
background-color: $colors[base]; // <- line 21
}
}
}
}
But I get a syntax error instead:
error sass/test.scss (Line 21: Invalid CSS after "...d-color: $color": expected ";", was "[base];")
You have the use the map-get function. Sass does not provide a special syntax for accessing values of a mapping.
#each $name, $colors in $themes {
[data-page="home"] {
#slider-pagers{
a.#{$name} {
background-color: map-get($colors, base);
}
}
}
}
Now you get the following output:
[data-page="home"] #slider-pagers a.ocean {
background-color: #0db0b8;
}
A good practice when using SassScript maps (not "source maps"; those are different) is to always quote the keys. For example:
$site-global: (
"ocean": (
"base": $_base-ocean,
"hover": darken($_base-ocean, $_base-hover)
)
);
In order to be compatible with CSS, Sass interprets some unquoted identifiers (including ocean) as color names and translates them internally to color values. When emitting compressed output, Sass will try to produce the smallest possible representation of those colors, which in this case is a hex code. Quoting the keys makes it clear that they should always be strings and should always be emitted with their string values.
Fixed Issue 1 !
It was a case of doing another map-get within a map-get. Once done, I had to reference the default value (this being base). As long as all my default values had a base value this seems to work fine:
#each $theme-colour, $color in $site-global {
[data-page="home"]{
#slider-pagers a.#{$theme-colour}{
background-color:map-get(map-get($site-global, $theme-colour), base);
}
}
}
How it still fails to minify when this code:
#{$variable_here}
Funny enough this code does not:
#slider-pagers a #{$theme-colour}{
or
#slider-pagers a#{$theme-colour}{
Thanks for responding, if anyone knows the is compiling issue that would be great.

Checking if a variable is defined in SASS

AS the title says I am trying to check whether a variable is defined in SASS. (I am using compass if that makes any different difference)
I've found the Ruby equivalent which is:
defined? foo
Gave that a shot in the dark but it just gave me the error:
defined": expected "{", was "?
I've found a work around (which is obviously just to define the variable in all cases, which in this case it actually makes more sense) but I'd really like to know if this is possible for the future
For Sass 3.3 and later
As of Sass 3.3 there is a variable-exists() function. From the changelog:
It is now possible to determine the existence of different Sass constructs using these new functions:
variable-exists($name) checks if a variable resolves in the current scope.
global-variable-exists($name) checks if a global variable of the given name exists.
...
Example usage:
$some_variable: 5;
#if variable-exists(some_variable) {
/* I get output to the CSS file */
}
#if variable-exists(nonexistent_variable) {
/* But I don't */
}
For Sass 3.2.x and earlier (my original answer)
I ran into the same problem today: trying to check if a variable is set, and if so adding a style, using a mixin, etc.
After reading that an isset() function isn't going to be added to sass, I found a simple workaround using the !default keyword:
#mixin my_mixin() {
// Set the variable to false only if it's not already set.
$base-color: false !default;
// Check the guaranteed-existing variable. If it didn't exist
// before calling this mixin/function/whatever, this will
// return false.
#if $base-color {
color: $base-color;
}
}
If false is a valid value for your variable, you can use:
#mixin my_mixin() {
$base-color: null !default;
#if $base-color != null {
color: $base-color;
}
}
If you're looking for the inverse, it's
#if not variable-exists(varname)
To check if it is undefined or falsy:
#if not variable-exists(varname) or not $varname
And if you want to set it only if it's undefined or null
$varname: VALUE !default;
Just as a complementary answer - you should have a look on the default keyword for certain use cases. It gives you the possibility to assign a default value to variables in case they are not defined yet.
You can assign to variables if they aren’t already assigned by adding
the !default flag to the end of the value. This means that if the
variable has already been assigned to, it won’t be re-assigned, but if
it doesn’t have a value yet, it will be given one.
Example:
In specific-variables.scss you have:
$brand: "My Awesome Brand";
In default-variables.scss you have:
$brand: company-name !default;
$brand-color: #0074BE !default;
Your project is built like this:
#import "specific-variables.scss";
#import "default-variables.scss";
#import "style.scss";
The value of brand will be My Awesome Brand and the value of brand color will be #0074BE.

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