How to optimize two css classes into one - css

I have a project made with react and I want to optimize the css.
I have this code:
.class-1 {
margin-top: 15px;
}
.class-2 {
margin-bottom: 15px;
}
Is there a possible way to optimize like this during the build?
.class-3 {
margin: 15px 0 15px 0;
}

You can add both classes to your HTML element or combine the margins into one class like this:
.class1 {
margin-top: 15px;
background-color: skyblue;
}
.class2 {
margin-bottom: 15px;
}
.class3 {
margin: 15px 0;
background-color: red;
}
<div class='class1 class2'>My element with 2 classes</div>
<div class='class3'>My element with 1 class</div>
It all depends if you want to keep the classes separate for other areas of your code, or if you will never need those margins in separate classes.

Related

SCSS/SASS - How to Specify Two Valid Parents for Nested CSS

Question: With SCSS, can we specify two different .main selectors? Say I want another one with margin-top: 50px while also inheriting all other conditions
I have inherited some SCSS from someone else. I have the following SCSS structure:
.main {
margin-top: 74px;
ul.tabs {
position: relative;
li.tab {
/*The rest of nested structure*/
}
}
}
It continues to nest (unfortunately) for many layers.
I have some other options (splitting the structure in two) which is a simple fix. Just curious if there's something better.
Thanks!
You should use a mixin:
#mixin sharedStyles{
//shared nested styles go here
}
.parentA{
margin-top:74px;
#include sharedStyles;
}
.parentB{
margin-top: 50px;
#include sharedStyles;
}
Here is a gist that illustrates the concept:
https://gist.github.com/Ryan-Haines/ba10888d0828d394851d3da6063f70bb
I recommend using sassmeister for rapid prototyping:
https://www.sassmeister.com
If you use a placeholder, as long as one selector is not inside a media query, it should group them together in the CSS. Ie
%mainStyles {
border: 1px solid black;
}
.main1 {
margin-top: 75px;
#extend %mainStyles;
}
.main2 {
margin-top: 50px;
#extend %mainStyles;
}
Should generate
.main1, .main2 {
border: 1px solid black;
}
.main1 {
margin-top: 75px;
}
.main2 {
margin-top: 50px;
}

Sass ampersand and parent styles

My HTML:
<div id="form" class="special">
<div class="header">My special form</div>
<div>
And the following sass code:
#form {
.header {
padding: 20px 10px;
.special & {
background: $special-color;
}
}
}
Which produces:
#form .header {
padding: 20px 10px;
}
.special #form .header {
background: #7cc52c;
}
However this doesn't give me the result I want. Instead of the CSS above I want to have: .special#form .header (the element form with class special, not the element .special which has form)
You can achieve your desired css this way.
#form {
.header {
padding: 20px 10px;
#at-root #{selector-replace(&, '#form', '.special#form')} {
background: blue;
}
}
}
This scss compiles to the following css
#form .header {
padding: 20px 10px;
}
.special#form .header {
background: blue;
}
Using the selector-replace function, you can easily change the part of the compound selector that needs changing. In this example, that would be replacing #form with .special#form. The #at-root directive ensures that the selector is placed at the top level and not nested within any selector.
When the parent selector is appended and nested as you did in your question, it reverses the selector. There are situations where this might be useful, one such situation is when working with Modernizr as illustrated in one of the slides on here
Hope this helps.
The simplest way to do this is by using #at-root and interpolation
$special-color:#7cc52c;
#form {
.header {
padding: 20px 10px;
// use #at-root to move .special out of #form .header
#at-root {
// append #form .header using the & selector
// note! you need to use interpolation #{} to
// remove the white space between .special and #form
.special#{&} {
background: $special-color;
}
}
}
}

How to Add flexibility to SASS for another color

I've got some Sass I've inherited that looks like below. I want to be able to specify a CSS tag to differentiate between green and another color (see anchor tag and comment).
Now, I have-
<div class="names"></div>
The link shows green. I want to be able do something like-
<div class="names myblue"></div>
And instead have it be a different color.
&.SpeakerCount3 {
.names {
text-align: center;
li {
text-align: center;
display: inline-block;
width: 82px;
margin-left: 5px;
&:first-child {
margin-left: 0;
}
}
img {
max-width: 100%;
}
h3 {
margin-top: 0;
a {
font-size: 10px;
}
}
}
}
.names {
min-height: 180px;
.photo {
margin-top: -21px;
}
img {
display: block;
border: 3px solid #282828;
margin: 0 auto;
}
h3 {
margin-top: 5px;
}
a {
font-size: 20px;
color: #5c5c5c; // this was green but I could not figure how to make it orange for css and green for kids
text-decoration: none;
}
}
.description {
margin-bottom: 15px;
min-height: 120px;
h3 {
margin: 5px 0 20px 0;
min-height: 40px;
}
}
Having seen the HTML code that was being hidden in your question, I should say that good class names generally should relate to state rather than properties - so the class name "myblue" should probably be replaced with something like "featured", "highlighted" etc. This is especially the case where you are asking for "myblue" to actually change the colour to Orange - something that may well confuse future maintainers. In the case that "myblue" is a company or feature name it may well be legitimate, but I would consider carefully if there is an alternative class name which does not include a colour name.
In Sass you could do something like-
a {
font-size: 20px;
color: #5c5c5c; // this was green but I could not figure how to make it orange for css and green for kids
text-decoration: none;
.myblue & {
color: orange;
}
}
As the "a" selector is contained within the ".names" selector though, this will result in a rendered rule of-
.myblue .names a {
color: orange;
}
As "names" is not a descendant of "myblue" in your DOM, the selector will not match - and this isn't what you want.
If you only want the rule to apply where both "names" and "myblue" are present I would write this-
.names {
min-height: 180px;
.photo {
margin-top: -21px;
}
img {
display: block;
border: 3px solid #282828;
margin: 0 auto;
}
h3 {
margin-top: 5px;
}
a {
font-size: 20px;
color: #5c5c5c; // this was green but I could not figure how to make it orange for css and green for kids
text-decoration: none;
}
&.myblue {
a {
color: orange;
}
}
}
The ampersand produces a combined selector, rather than the descendant selector you would get with a space (this is Sass only - not valid CSS).
Alternatively, if you want the "myblue" class selector to apply even without the "names" class, then simply do this-
.names {
min-height: 180px;
.photo {
margin-top: -21px;
}
img {
display: block;
border: 3px solid #282828;
margin: 0 auto;
}
h3 {
margin-top: 5px;
}
a {
font-size: 20px;
color: #5c5c5c; // this was green but I could not figure how to make it orange for css and green for kids
text-decoration: none;
}
}
.myblue {
a {
color: orange;
}
}
As the "myblue" selector appears after the "names" selector, the color property for the link will override the color set in "names" - leaving all other properties for the link and other elements intact. This solution simply utilises the CSS cascade to achieve the desired effect.

CSS - Extending class properties

I'm pretty new to CSS and have been finding my way around so far.
I am creating these button like links with shadows and stuff. Now there are several such buttons required on the site - everything about the buttons is same - except few properties change like width and font size.
Now instead of copying the same code - over and over for each button - is there a way of extending the button and adding just the properties that change.
Example of two buttons - css
.ask-button-display {
background: #8BAF3B;
border-radius: 4px;
display: block;
letter-spacing: 0.5px;
position: relative;
border-color: #293829;
border-width: 2px 1px;
border-style: solid;
text-align:center;
color: #FFF;
width:350px;
font-size: 20px;
font-weight: bold;
padding:10px;
}
.ask-button-submit {
background: #8BAF3B;
border-radius: 4px;
display: block;
letter-spacing: 0.5px;
position: relative;
border-color: #293829;
border-width: 2px 1px;
border-style: solid;
text-align:center;
color: #FFF;
font-weight: bold;
width:75px;
font-size: 12px;
padding: 1px;
}
And this is how I'm currently using it in my html
Ask a Question Submit
So I'm wondering if there is a cleaner way to do this - like
.button {
/* PUT ALL THE COMMON PROPERTIES HERE */
}
AND THEN SOMEHOW EXTEND IT LIKE
.button #display {
/* THE DIFFERENT PROPERTIES OF Display BUTTON */
}
.button #ask {
/* THE DIFFERENT PROPERTIES OF Ask BUTTON */
}
But I'm not sure how to do this.
Thanks for your inputs
You can add multiple classes to one element, so have one .button class which covers everything, then a .button-submit class, which adds things in.
For example:
.button {
padding: 10px;
margin: 10px;
background-color: red;
}
.button-submit {
background-color: green;
}​
See a live jsFiddle here
In your case, the following should work:
.button {
background: #8BAF3B;
border-radius: 4px;
display: block;
letter-spacing: 0.5px;
position: relative;
border-color: #293829;
border-width: 2px 1px;
border-style: solid;
text-align:center;
color: #FFF;
width:350px;
font-size: 20px;
font-weight: bold;
padding:10px;
}
.button-submit {
width:75px;
font-size: 12px;
padding: 1px;
}​
See a live jsFiddle here
You might want to try this:
.button {
padding: 10px;
margin: 10px;
background-color: red;
}
.button.submit {
background-color: green;
}
.button.submit:hover {
background-color: #ffff00;
}
This way you avoid repeating the word and will able to use the classes in the elements like this:
Ask a Question
Submit
See the example in JSFiddle (http://goo.gl/6HwroM)
Rather than repeat the common "Add a button class to the element" answer I'm going to show you something new in the weird and whacky world of new age CSS, or better known as SCSS!
This reuse of code in stylesheets can be achieved with something called a 'Mixin'. What this allows us to do is reuse certain styles by using the '#include' attribute.
Let me give you an example.
#mixin button($button-color) {
background: #fff;
margin: 10px;
color: $color;
}
and then whenever we have a button we say
#unique-button {
#include button(#333);
...(additional styles)
}
Read more here: http://sass-lang.com/tutorial.html.
Spread the word!!!
You can do this since you can apply more than one class to an element. Create your master class and and other smaller classes and then just apply them as needed. For example:
Ask a Question Submit
This would apply the button and submit classes you would create while allowing you to also apply those classes separately.
Modify your code example along the lines of:
.master_button {
/* PUT ALL THE COMMON PROPERTIES HERE */
}
AND THEN SOMEHOW EXTEND IT LIKE
.button_display {
/* THE DIFFERENT PROPERTIES OF Display BUTTON */
}
.button_ask {
/* THE DIFFERENT PROPERTIES OF Ask BUTTON */
}
And apply like:
Ask a Question
Submit
.ask-button-display,
.ask-button-submit {
/* COMMON RULES */
}
.ask-button-display {
}
.ask-button-submit {
}
You may want to look into Sass. With Sass you can basically create variables in your css file and then re-use them over and over. http://sass-lang.com/
The following example was taken from Sass official website:
$blue: #3bbfce;
$margin: 16px;
.content-navigation {
border-color: $blue;
color:
darken($blue, 9%);
}
.border {
padding: $margin / 2;
margin: $margin / 2;
border-color: $blue;
}
Add a button class to both links for the common parts
.button {
background: #8BAF3B;
border-radius: 4px;
display: block;
letter-spacing: 0.5px;
position: relative;
border-color: #293829;
border-width: 2px 1px;
border-style: solid;
text-align:center;
color: #FFF;
}
Keep in your other classes the rules that aren't common.
And your HTML will be
Ask a Question
Submit
Without changing/ adding new classes you can add styles to all elements with a class name starting with "ask-button"... (whatever the elements with the class are; button, anchor, div etc.) let's say your buttons are divs then:
div[class^="ask-button"] {
// common css properties
}
You can also list all classes that will have common properties like this:
.ask-button-display,
.ask-button-submit {
// common css properties here
}
And then you add the separate styling for each button:
.ask-button-display{
// properties only for this button
}
.ask-button-submit {
// properties only for this button
}

SASS, when to extend?

I'm currently working on a team that uses SASS. I see that we are extending styles that are very simple and to me I don't see the benefit of doing this. Am I missing something?
Here are some examples of a _Common.scss that is imported and used throughout other sass files:
.visibility-hidden{visibility: hidden;}
.display-inline { display: inline; }
.display-inline-block { display: inline-block; }
.display-block { display: block; }
.display-none { display: none; }
.display-box { display: box; }
.float-left { float: left; }
.float-right { float: right; }
.clear-both { clear: both; }
.width-percent-100 { width: 100%; }
.width-percent-65 { width: 65%; }
.width-percent-50 { width: 50%; }
.width-percent-45 { width: 45%; }
.width-percent-40 { width: 40%; }
.width-percent-33 { width: 33%; }
.width-percent-30 { width: 30%; }
.width-percent-20 { width: 20%; }
.height-percent-100 { height: 100%; }
.cursor-pointer { cursor: pointer; }
.underline { text-decoration: underline; }
.text-decoration-none { text-decoration: none; }
.bold { font-weight: bold; }
.font-weight-normal { font-weight: normal; }
.text-align-center { text-align: center; }
.text-align-left { text-align: left; }
.text-align-right { text-align: right; }
.font-10 { font-size: 10px; }
.font-11 { font-size: 11px; }
.font-12 { font-size: 12px; }
.font-13 { font-size: 13px; }
.font-14 { font-size: 14px; }
.font-15 { font-size: 15px; }
.font-16 { font-size: 16px; }
.font-17 { font-size: 17px; }
.font-18 { font-size: 18px; }
.font-percent-65 { font-size: 65%; }
.font-percent-80 { font-size: 80%; }
.font-percent-90 { font-size: 90%; }
.font-percent-100 { font-size: 100%; }
.font-percent-110 { font-size: 110%; }
.font-percent-120 { font-size: 120%; }
.font-percent-130 { font-size: 130%; }
.font-percent-140 { font-size: 140%; }
.font-percent-150 { font-size: 150%; }
.font-percent-160 { font-size: 160%; }
.font-percent-170 { font-size: 170%; }
.font-percent-180 { font-size: 180%; }
Example:
#CategoriesContainer
{
ul{
li{
&:first-child{
#extend .font-11;
}
a
{
#extend .font-11;
#extend .text-decoration-none;
}
}
}
}
You should only use extend when you have a certain attribute set that will be used multiple times. The sheer stupidy of extending a class with a class with one attribute that has the unit value worked into the name of it is incomprehensible.
A better example for a reason to extend can be found in the reference guide
Say we have 2 classes
.error {
border: 1px #f00;
background-color: #fdd;
}
.seriousError {
border-width: 3px;
}
.error is a general no interesting style but a serious error should be really clear.
.seriousError is created to thicken the line, the only problem is that now we have to use both classes in the html to combine the styles.
Because we're lazy and just want to use one class and not duplicate code that might be changed in the future we can extend .seriousError with .error
.seriousError {
#extend .error;
border-width: 3px;
}
Now we didn't duplicate the code in our sass file but did get the right styles on the page.
Check out the reference guide for more/better examples.
Just please for the sake of kittens stop extending classes with one attribute classes. And don't implicitly state the value/attributes in the selector, thats not very semantic.
You, and your team, should read this post which explains a few problems with the aproach you take here vs semantic code. Couldn't find a better tuned post this quick.
You aren't missing anything, this is just bloated code in poor form and not a great way to extend classes.
There is maybe one (bad) reason I can imagine why this would be used. If for example .font-10 needs to be .7em instead of 10px, it can be easily changed - but then you've just defeated the point of naming the class "font10". Something like small-font would even make more sense in that case (and I'm not suggesting you use that either).
I won't discuss the merits of semantic class names and the folly of presentational ones (especially as literal as these are), but I will suggest that this is a very narrow use of extending classes. With a 1:1 mapping of class name to property/value, you've practically defeated the purpose of #extend, which is supposed to make you write less CSS.
Better example of what to use #extend for:
.media {
padding:1em;
border-color:blue;
background-color:red;
clear:left;
}
.my-media {
#extend .media;
background-color:green;
}
Atomic CSS
The technique of very simple CSS rules does have a bit of precedent - at Yahoo! they call it Atomic CSS. Thierry Koblentz argues in this Smashing Magazine article for using the simple classes directly in your markup, similar to inline styling. This can be helpful on very large projects across multiple web properties, where styles are not consistent. Base styles for OOCSS components can't be reused as much in such a situation, causing you to have to write many more lines of extension classes or overrides.
The downside is, of course, as Wesley mentioned, that it is much more difficult to make changes across your entire project's styles, such as updating the text size of a specific selector.
I've been playing around with a variant of this technique recently in a fairly large project, where styles can often be one-off. In an effort to avoid the I try to avoid putting hard values directly in the selectors. For instance, the following css (example fiddle):
_colors.scss
.text-white {
color: $white;
}
.blue {
#extend .text-white;
background: $blue;
}
_effects.scss
.circle {
width: 50px;
height: 50px;
border-radius: 50%;
text-align: center;
line-height: 50px;
font-size: 40px;
}
.matted {
border: 4px solid $white;
}
.shadow {
#include box-shadow(0 1px 4px 1px rgba($black, 0.25));
}
HTML:
<div class="blue matted circle shadow">?</div>
Specificity issues
One last thing to keep in mind if you decide to use this technique - it can cause specificity problems if you're extending base-level classes that use the same CSS properties. For instance, in the following example (fiddle), how would your border-radius appear? You wanted the top to be squared off (no border-radius) but this isn't happening, because the .circle class is further down in your css and just as specific (single class) as the other effects. This is a bit of a contrived example, but if you reuse CSS properties across your atomic selectors, this can be a real problem.
_colors.scss
.text-white {
color: white;
}
.blue {
#extend .text-white;
background: royalblue;
}
_effects.scss
.squared-top {
border-top-left-radius: 0;
border-top-right-radius: 0;
}
.rounded {
border-radius: 10px;
}
.circle {
width: 50px;
height: 50px;
border-radius: 50%;
}
HTML:
<span class="circle blue rounded squared-top"></span>
If you do it that way you can also use it directly in the HTML - so it looks like they took the OOCSS path and because it's already in the CSS you can now also extend to it. Very flexible but it could also turn very messy.
Extend option is used poorly here. It should be used for extending classes with more content and in that case extend can be very helpful.You can find more about extend and its options here.

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