Throughout the codebase, Bulma uses Sass mixins to enhance and facilitate the CSS output. While these mixins are mainly used within the context of Bulma, they are of course available for you to re-use in your own projects.
--- title: Mixins layout: documentation doc-tab: utilities doc-subtab: mixins breadcrumb: - home - documentation - utilities - utilities-mixins ---
Throughout the codebase, Bulma uses Sass mixins to enhance and facilitate the CSS output. While these mixins are mainly used within the context of Bulma, they are of course available for you to re-use in your own projects.
These mixins create a visual HTML element.
{% include elements/anchor-bis.html name="Arrow" %}
The arrow() mixin creates a down-facing arrow. The $color parameter defines the color of the arrow.
The hamburger() mixin creates a 16x16px set of 3 horizontal bars grouped within square. The dimensions of this square are defined by the $dimensions parameter.
The delete() mixin creates a 20x20px circle containing a cross. It comes with 3 modifiers: is-small, is-medium and is-large.
The loader() mixin creates a 1em spinning circle.
The fa() mixin creates a square inline-block element, ideal for containing a Font Awesome icon, or any other type of icon font.
The first $size parameter defines the icon font size.
The second $dimensions parameter defines the dimensions of the square container.
These mixins add CSS rules to the element.
{% include elements/anchor-bis.html name="Block" %}
The block() mixin adds spacing below an element, but only if it's not the last child.
The $spacing parameter defines the value of the margin-bottom.
This element has a margin-bottom.
This element too.
Not this one because it's the last child.
{% endcapture %} {% include elements/snippet.html content=block %} {% include elements/anchor-bis.html name="Overlay" %}
The overlay() mixin makes the element cover its closest positioned ancestor.
The $offset parameter defines how far inside the element is positioned from each edge (top, bottom, left and right).
The center() mixin allows you to absolutely position an element with fixed dimensions at the center of its closest positioned ancestor.
The value of the $width parameter should be the width of the element the mixin is applied on.
Unless the element has square dimensions, the second parameter $height is required and its value should be the height of the element the mixin is applied on.
The placeholder() mixin allows you to change the style of an input's placeholder.
The $offset parameter defines how far inside the element is positioned from each edge (top, bottom, left and right).
The clearfix() mixin adds a ::after pseudo-element with a clear: both rule.
This is a short image description.
This text is following the clearfix element and is correctly placed after.
{% endcapture %} {% include elements/snippet.html content=clearfix %} {% include elements/anchor-bis.html name="Reset" %}
The reset() mixin applies a soft style reset. This is especially useful for <button> elements.
The unselectable() mixin makes an element not selectable. This is to prevent the text to be selected when double-clicked.
This text is selectable.
This text is not selectable.
{% endcapture %} {% include elements/snippet.html content=unselectable %} {% include elements/anchor-bis.html name="Overflow Touch" %}
The overflow-touch() mixin add the -webkit-overflow-scrolling: touch; rule to the element.
Bulma has a global $rtl flag, which allows the framework to output a Right-to-left version of the CSS. By default, this flag's value is set to false. This means the framework output a Left-to-right version.
The mixins @mixin ltr and @mixin rtl are here to output CSS rules based on the value of $rtl:
$rtl: true, @include ltr outputs nothing
$rtl: false, @include rtl outputs nothing
This is useful for properties that are specific to the side of an element.
The ltr-position() mixin is a quick way to switch between left and right CSS properties when dealing with positioned elements.
The first $spacing parameter defines the value of the offset, whether it's right or left.
The second $right parameter defines if the property outputs right (default) or left.
Here is what the output looks like with a $spacing parameter set to 1rem:
| Flag → | $rtl: false; |
$rtl: true; |
|---|---|---|
@include ltr-position(1rem, true) |
right: 1rem |
left: 1rem |
@include ltr-position(1rem, false) |
left: 1rem |
right: 1rem |
Sass source
{% highlight sass %}.bulma-ltr-position-mixin { @include ltr-position(1rem, false); border-radius: 0.25em; position: absolute; top: 1rem; }{% endhighlight %}CSS output
{% highlight css %}.bulma-ltr-position-mixin { left: 1rem; border-radius: 0.25em; position: absolute; top: 1rem; }{% endhighlight %} {% capture ltr-position %}Cras mattis consectetur purus sit amet fermentum. Nulla vitae elit libero, a pharetra augue. Aenean lacinia bibendum nulla sed consectetur. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Curabitur blandit tempus porttitor. Maecenas faucibus mollis interdum.
The ltr-property() mixin works like the ltr-position() mixin but allows you to choose which CSS property to set. The mixin will append -right or -left to that property. This is especially useful for margin and padding.
The first $property parameter which property you want to "flip" left and right.
The second $spacing parameter defines the value of the offset, whether it's right or left.
The third $right parameter defines if the property outputs right (default) or left.
Here is what the output looks like with a $spacing parameter set to 1rem:
| Flag → | $rtl: false; |
$rtl: true; |
|---|---|---|
@include ltr-property("margin", 1rem, true) |
margin-right: 1rem |
margin-left: 1rem |
@include ltr-property("margin", 1rem, false) |
margin-left: 1rem |
margin-right: 1rem |
Sass source
{% highlight sass %}.bulma-ltr-property-mixin { @include ltr-property("margin", 1rem, false); border-radius: 0.25em; }{% endhighlight %}CSS output
{% highlight css %}.bulma-ltr-property-mixin { margin-left: 1rem; border-radius: 0.25em; }{% endhighlight %} {% capture ltr-property %}Cras mattis consectetur purus sit amet fermentum. Nulla vitae elit libero, a pharetra augue. Aenean lacinia bibendum nulla sed consectetur. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Curabitur blandit tempus porttitor. Maecenas faucibus mollis interdum.