Vue-multiselect: Add bootstrap style for vue-multiselect component.

[phuongthuan]

The Question is how to add bootstrap style for dropdown or tag to vue-multiselect component ??
Thanks

[vpratfr]

Here is the SASS file I am using. This is for Bootstrap 4 and tries to reuse as much as BS variables as possible.

Would be nice to get that file into the main repository for future reference.

```$sass
@import "~bootstrap/scss/functions";
@import "~bootstrap/scss/variables";

$vue-multiselect-padding-x : $custom-select-padding-x !default;
$vue-multiselect-padding-y : $custom-select-padding-y !default;
$vue-multiselect-min-height : $custom-select-height !default;
$vue-multiselect-border-radius : $border-radius !default;
$vue-multiselect-border-color : $custom-select-border-color !default;
$vue-multiselect-border-width : 1px !default;
$vue-multiselect-disabled-opacity : $btn-disabled-opacity !default;
$vue-multiselect-placeholder-color : $text-muted !default;
$vue-multiselect-bg : $custom-select-bg !default;
$vue-multiselect-color : $custom-select-color !default;
$vue-multiselect-disabled-bg : $custom-select-disabled-bg !default;
$vue-multiselect-disabled-color : $custom-select-disabled-color !default;

$vue-multiselect-option-selected-bg : #f3f3f3 !default;
$vue-multiselect-option-selected-color : $body-color !default;
$vue-multiselect-option-highlight-color : #fff !default;
$vue-multiselect-option-highlight-bg : theme-color("primary") !default;
$vue-multiselect-option-selected-highlight-color : #fff !default;
$vue-multiselect-option-selected-highlight-bg : theme-color("secondary") !default;

$vue-multiselect-tag-color : $dark !default;
$vue-multiselect-tag-bg : $light !default;
$vue-multiselect-tag-font-size : $badge-font-size !default;
$vue-multiselect-tag-font-weight : normal !default;
$vue-multiselect-tag-icon-size : 1.7rem !default;
$vue-multiselect-tag-icon-color : $vue-multiselect-tag-color !default;
$vue-multiselect-tag-icon-color-hover : white !default;
$vue-multiselect-tag-icon-bg-hover : $danger !default;
$vue-multiselect-tag-padding-x : .4rem !default;
$vue-multiselect-tag-padding-y : .25rem !default;
$vue-multiselect-tag-border-radius : $badge-border-radius !default;

$vue-multiselect-arrow-color : $custom-select-color !default;
$vue-multiselect-arrow-size : 5px !default;
$vue-multiselect-arrow-padding : 8px !default;

$vue-multiselect-spinner-size : 16px !default;
$vue-multiselect-spinner-thickness : 2px !default;
$vue-multiselect-spinner-margin : -$vue-multiselect-spinner-size/2 !default;
$vue-multiselect-spinner-color : $dark !default;

// --------------------------------
// Select field
//--

fieldset[disabled] .multiselect {
pointer-events : none;
}

.multiselect,
.multiselect__input,
.multiselect__single {
font-family : inherit;
font-size : inherit;
touch-action : manipulation;
}

.multiselect {
box-sizing : content-box;
display : block;
position : relative;
width : 100%;
min-height : $vue-multiselect-min-height;
text-align : left;
color : $vue-multiselect-color;

& * {
    box-sizing : border-box;
}

&:focus {
    outline : none;
}

}

.multiselect--disabled {
pointer-events : none;
opacity : $vue-multiselect-disabled-opacity;
}

.multiselect--active {
z-index : 50;

&:not(.multiselect--above) .multiselect__current,
&:not(.multiselect--above) .multiselect__input,
&:not(.multiselect--above) .multiselect__tags {
    border-bottom-left-radius  : 0;
    border-bottom-right-radius : 0;
}

& .multiselect__select {
    transform : rotateZ(180deg);
}

}

.multiselect--above.multiselect--active .multiselect__current,
.multiselect--above.multiselect--active .multiselect__input,
.multiselect--above.multiselect--active .multiselect__tags {
border-top-left-radius : 0;
border-top-right-radius : 0;
}

.multiselect__input,
.multiselect__single {
position : relative;
display : inline-block;
min-height : $vue-multiselect-min-height / 2;
line-height : $vue-multiselect-min-height / 2;
border : none;
border-radius : $vue-multiselect-border-radius;
background : $vue-multiselect-bg;
padding : 0 0 0 $vue-multiselect-padding-x;
width : calc(100%);
transition : border 0.1s ease;
box-sizing : border-box;
margin-bottom : $vue-multiselect-padding-y;
vertical-align : top;
}

.multiselect__input::placeholder {
color : $vue-multiselect-placeholder-color;
}

.multiselect__tag ~ .multiselect__input,
.multiselect__tag ~ .multiselect__single {
width : auto;
}

.multiselect__input:hover,
.multiselect__single:hover {
border-color : #cfcfcf;
}

.multiselect__input:focus,
.multiselect__single:focus {
border-color : #a8a8a8;
outline : none;
}

.multiselect__single {
padding-left : $vue-multiselect-padding-x;
margin-bottom : $vue-multiselect-padding-y;
}

.multiselect__tags-wrap {
display : inline
}

.multiselect__tags {
min-height : $vue-multiselect-min-height;
display : block;
padding : $vue-multiselect-padding-y $vue-multiselect-min-height 0 $vue-multiselect-padding-y;
border-radius : $vue-multiselect-border-radius;
border : $vue-multiselect-border-width solid $vue-multiselect-border-color;
background : $vue-multiselect-bg;
font-family : inherit;
font-size : inherit;
}

.multiselect__tag {
position : relative;
display : inline-block;
padding : $vue-multiselect-tag-padding-y ($vue-multiselect-tag-icon-size + $vue-multiselect-tag-padding-x) $vue-multiselect-tag-padding-y $vue-multiselect-tag-padding-x;
border-radius : $vue-multiselect-tag-border-radius;
margin-right : $vue-multiselect-tag-padding-x;
color : $vue-multiselect-tag-color;
background : $vue-multiselect-tag-bg;
white-space : nowrap;
overflow : hidden;
max-width : 100%;
text-overflow : ellipsis;
font-size : $vue-multiselect-tag-font-size;
font-weight : $vue-multiselect-tag-font-weight;
}

.multiselect__tag-icon {
cursor : pointer;
margin-left : $vue-multiselect-tag-padding-y;
position : absolute;
right : 0;
top : 0;
bottom : 0;
font-style : initial;
width : $vue-multiselect-tag-icon-size;
text-align : center;
line-height : $vue-multiselect-tag-icon-size;
transition : all 0.2s ease;
font-size : $vue-multiselect-tag-font-size;
font-weight : $vue-multiselect-tag-font-weight;
}

.multiselect__tag-icon:after {
content : "×";
color : $vue-multiselect-tag-icon-color;
font-size : 220%;
}

.multiselect__tag-icon:focus,
.multiselect__tag-icon:hover {
background : $vue-multiselect-tag-icon-bg-hover;
}

.multiselect__tag-icon:focus:after,
.multiselect__tag-icon:hover:after {
color : $vue-multiselect-tag-icon-color-hover;
}

.multiselect__current {
line-height : $vue-multiselect-min-height / 2;
min-height : $vue-multiselect-min-height;
box-sizing : border-box;
display : block;
overflow : hidden;
padding : 8px 30px 0 12px;
white-space : nowrap;
margin : 0;
text-decoration : none;
border-radius : $vue-multiselect-border-radius;
border : 1px solid $vue-multiselect-border-color;
cursor : pointer;
}

.multiselect__select {
line-height : $vue-multiselect-min-height / 2;
display : block;
position : absolute;
box-sizing : border-box;
width : $vue-multiselect-min-height;
height : $vue-multiselect-min-height;
right : 0;
top : 0;
padding : ($vue-multiselect-arrow-padding) $vue-multiselect-arrow-padding;
margin : 0;
text-decoration : none;
text-align : center;
cursor : pointer;
transition : transform 0.2s ease;
}

.multiselect__select:before {
position : relative;
right : 0;
top : 50%;
color : $vue-multiselect-arrow-color;
border-style : solid;
border-width : $vue-multiselect-arrow-size $vue-multiselect-arrow-size 0 $vue-multiselect-arrow-size;
border-color : $vue-multiselect-arrow-color transparent transparent transparent;
content : "";
}

.multiselect__placeholder {
color : $vue-multiselect-placeholder-color;
display : inline-block;
margin-bottom : 10px;
padding-top : 2px;
}

.multiselect--active .multiselect__placeholder {
display : none;
}

.multiselect__content-wrapper {
position : absolute;
display : block;
background : $vue-multiselect-bg;
width : 100%;
max-height : 240px;
overflow : auto;
border : $vue-multiselect-border-width solid $vue-multiselect-border-color;
border-top : none;
border-bottom-left-radius : $vue-multiselect-border-radius;
border-bottom-right-radius : $vue-multiselect-border-radius;
z-index : 50;
-webkit-overflow-scrolling : touch;
}

.multiselect__content {
list-style : none;
display : inline-block;
padding : 0;
margin : 0;
min-width : 100%;
vertical-align : top;
}

.multiselect--above .multiselect__content-wrapper {
bottom : 100%;
border-radius : $vue-multiselect-border-radius $vue-multiselect-border-radius 0 0;
border-bottom : none;
border-top : $vue-multiselect-border-width solid $vue-multiselect-border-color;
}

.multiselect__content::webkit-scrollbar {
display : none;
}

.multiselect__element {
display : block;
}

.multiselect__option {
display : block;
padding : $vue-multiselect-padding-y $vue-multiselect-padding-x;
min-height : $vue-multiselect-min-height;
line-height : $vue-multiselect-min-height / 2;
text-decoration : none;
text-transform : none;
vertical-align : middle;
position : relative;
cursor : pointer;
white-space : nowrap;
}

.multiselect__option:after {
top : 0;
right : 0;
position : absolute;
line-height : $vue-multiselect-min-height;
padding-right : 12px;
padding-left : 20px;
font-family : inherit;
font-size : inherit;
}

.multiselect__option--highlight {
background : $vue-multiselect-option-highlight-bg;
outline : none;
color : $vue-multiselect-option-highlight-color;
}

.multiselect__option--highlight:after {
content : attr(data-select);
background : $vue-multiselect-option-highlight-bg;
color : $vue-multiselect-option-highlight-color;
}

.multiselect__option--selected {
background : $vue-multiselect-option-selected-bg;
color : $vue-multiselect-option-selected-color;
font-weight : bold;
}

.multiselect__option--selected:after {
content : attr(data-selected);
color : silver;
}

.multiselect__option--selected.multiselect__option--highlight {
background : $vue-multiselect-option-selected-highlight-bg;
color : $vue-multiselect-option-selected-highlight-color;
}

.multiselect__option--selected.multiselect__option--highlight:after {
background : $vue-multiselect-option-selected-highlight-bg;
content : attr(data-deselect);
color : $vue-multiselect-option-selected-highlight-color;
}

.multiselect--disabled {
background : $vue-multiselect-disabled-bg;
pointer-events : none;
}

.multiselect--disabled .multiselect__current,
.multiselect--disabled .multiselect__select {
background : $vue-multiselect-disabled-bg;
color : $vue-multiselect-disabled-color;
}

.multiselect__option--disabled {
background : $vue-multiselect-disabled-bg;
color : $vue-multiselect-disabled-color;
cursor : text;
pointer-events : none;
}

.multiselect__option--group {
background : $vue-multiselect-disabled-bg;
color : $vue-multiselect-disabled-color;

&.multiselect__option--highlight {
    background : $vue-multiselect-disabled-color;
    color      : $vue-multiselect-disabled-bg;
}

&.multiselect__option--highlight:after {
    background : $vue-multiselect-disabled-color;
}

}

.multiselect__option--disabled.multiselect__option--highlight {
background : $vue-multiselect-disabled-bg;
}

.multiselect__option--group-selected.multiselect__option--highlight {
background : $vue-multiselect-option-selected-highlight-bg;
color : $vue-multiselect-option-selected-highlight-color;
}

.multiselect__option--group-selected.multiselect__option--highlight:after {
background : $vue-multiselect-option-selected-highlight-bg;
content : attr(data-deselect);
color : $vue-multiselect-option-selected-highlight-color;
}

.multiselect-enter-active,
.multiselect-leave-active {
transition : all 0.15s ease;
}

.multiselect-enter,
.multiselect-leave-active {
opacity : 0;
}

.multiselect__strong {
margin-bottom : $vue-multiselect-padding-y;
line-height : $vue-multiselect-min-height/2;
display : inline-block;
vertical-align : top;
}

// --------------------------------
// Spinner
//--

.multiselect__spinner {
position : absolute;
right : 0;
top : 0;
width : $vue-multiselect-min-height;
height : $vue-multiselect-min-height;
background : $vue-multiselect-bg;
display : block;

&:before,
&:after {
    position         : absolute;
    content          : "";
    top              : 50%;
    left             : 50%;
    margin           : $vue-multiselect-spinner-margin 0 0 $vue-multiselect-spinner-margin;
    width            : $vue-multiselect-spinner-size;
    height           : $vue-multiselect-spinner-size;
    border-radius    : 100%;
    border           : $vue-multiselect-spinner-thickness solid transparent;
    border-top-color : $vue-multiselect-spinner-color;
    box-shadow       : 0 0 0 1px transparent;
}

&:before {
    animation                 : spinning 2.4s cubic-bezier(0.41, 0.26, 0.2, 0.62);
    animation-iteration-count : infinite;
}

&:after {
    animation                 : spinning 2.4s cubic-bezier(0.51, 0.09, 0.21, 0.8);
    animation-iteration-count : infinite;
}

}

@keyframes spinning {
from {
transform : rotate(0)
}
to {
transform : rotate(2turn)
}
}

// --------------------------------
// Loading state
//--

.multiselect__loading-enter-active,
.multiselect__loading-leave-active {
transition : opacity 0.4s ease-in-out;
opacity : 1;
}

.multiselect__loading-enter,
.multiselect__loading-leave-active {
opacity : 0;
}

// --------------------------------
// RTL adjustments
//--

*[dir="rtl"] {
.multiselect {
text-align : right;
}
.multiselect__select {
right : auto;
left : 1px;
}
.multiselect__tags {
padding : $vue-multiselect-padding-y $vue-multiselect-padding-y 0 $vue-multiselect-min-height;
}
.multiselect__content {
text-align : right;
}
.multiselect__option:after {
right : auto;
left : 0;
}
.multiselect__clear {
right : auto;
left : 12px;
}
.multiselect__spinner {
right : auto;
left : 1px;
}
}
```

[rcheung9]

@vpratfr Can you compile that and post the CSS?

[vpratfr]

Hi,

Currently I cannot allocate more time to this. Sorry. I will move back to Select2 because of the few other issues I had with getting everything to work nicely for regular form submissions.

That should compile smoothly though, you just need to pull Bootstrap 4 latest via NPM/Yarn and your favourite SASS compiler.

[580]

@vpratfr Thank you so much for sharing the sass file. Works great on my side.

[shentao]

Whoa! Nice work @vpratfr! What would you say if we added that to the docs? As an alternative styling?

[vpratfr]

Do whatever you like with it. As long as it may help others :)

Maybe a separate repo or a dedicated /themes/bootstrap4 with all NPM stuff to compile it and build it would be nice.

[ghenry]

Happy to sponsor this styling work.

[roszell]

I'd love to see this as well, specifically with support for Bootstrap 4 validation styling.

[mozebdi]

I am currently working on a project that uses vue-multiselect in combination with vue-bootstrap. Is the SASS file posted here feasible for prod use on Bootstrap 4? And is there any progress on an official Bootstrap 4 theme for vue-multiselect? Just curious 😄

[ghenry]

I'm using it with bootstrap-vue OK. I can't get it to work well inside a form-group though (input with an icon on the left hand side).

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[arrancardnell]

For those using vue-multiselect alongside Bootstrap 3, I modified the SASS that @vpratfr provided to work with BS3 (v3.3.7).

It might not be exactly what you're after (I liked the tags as they were already), but it should certainly given someone a good starting point and I'm more than happy for this to be included as an alternative styling if you find it useful.

// #############################################################################
// Multiselect
// Custom styling for the VueJS multiselect plugin.

@import "../libs/bootstrap-sass/bootstrap/variables";
@import "../settings/variables";

$vue-multiselect-padding-x : $padding-base-horizontal !default;
$vue-multiselect-padding-y : $padding-base-vertical !default;
$vue-multiselect-min-height : $input-height-base !default;
$vue-multiselect-line-height : $line-height-base !default;
$vue-multiselect-border-radius : $input-border-radius !default;
$vue-multiselect-border-color : $input-border !default;
$vue-multiselect-border-width : 1px !default;
$vue-multiselect-disabled-opacity : .65 !default;
$vue-multiselect-placeholder-color : $text-muted !default;
$vue-multiselect-bg : $input-bg !default;
$vue-multiselect-color : $input-color !default;
$vue-multiselect-disabled-bg : $input-bg-disabled !default;
$vue-multiselect-disabled-color : $gray-light !default;

$vue-multiselect-option-selected-bg : #f3f3f3 !default;
$vue-multiselect-option-selected-color : $text-color !default;
$vue-multiselect-option-highlight-color : #fff !default;
$vue-multiselect-option-highlight-bg : $brand-primary !default;
$vue-multiselect-option-selected-highlight-color : #fff !default;
$vue-multiselect-option-selected-highlight-bg : $brand-danger !default;

$vue-multiselect-tag-color : #fff !default;
$vue-multiselect-tag-bg : #41B883 !default;
$vue-multiselect-tag-font-size : 75% !default;
$vue-multiselect-tag-font-weight : 700 !default;
$vue-multiselect-tag-line-height : 0.9 !default;
$vue-multiselect-tag-icon-size : 2rem !default;
$vue-multiselect-tag-icon-color : #266D4D !default;
$vue-multiselect-tag-icon-color-hover : white !default;
$vue-multiselect-tag-icon-bg-hover : #369A6E !default;
$vue-multiselect-tag-padding-x : .4rem !default;
$vue-multiselect-tag-padding-y : 4px !default;
$vue-multiselect-tag-border-radius : $border-radius-base !default;

$vue-multiselect-arrow-color : $input-color !default;
$vue-multiselect-arrow-size : 5px !default;
$vue-multiselect-arrow-padding : 8px !default;

$vue-multiselect-spinner-size : 16px !default;
$vue-multiselect-spinner-thickness : 2px !default;
$vue-multiselect-spinner-margin : -$vue-multiselect-spinner-size/2 !default;
$vue-multiselect-spinner-color : $brand-dark !default;

// --------------------------------
// Select field
//--

fieldset[disabled] .multiselect {
    pointer-events : none;
}

.multiselect,
.multiselect__input,
.multiselect__single {
    font-family  : inherit;
    font-size    : inherit;
    touch-action : manipulation;
}

.multiselect {
    box-sizing : content-box;
    display    : block;
    position   : relative;
    width      : 100%;
    min-height : $vue-multiselect-min-height;
    text-align : left;
    color      : $vue-multiselect-color;

    & * {
        box-sizing : border-box;
    }

    &:focus {
        outline : none;
    }
}

.multiselect--disabled {
    pointer-events : none;
    opacity        : $vue-multiselect-disabled-opacity;
}

.multiselect--active {
    z-index : $zindex-dropdown;

    &:not(.multiselect--above) .multiselect__current,
    &:not(.multiselect--above) .multiselect__input,
    &:not(.multiselect--above) .multiselect__tags {
        border-bottom-left-radius  : 0;
        border-bottom-right-radius : 0;
    }

    & .multiselect__select {
        transform : rotateZ(180deg);
    }
}

.multiselect--above.multiselect--active .multiselect__current,
.multiselect--above.multiselect--active .multiselect__input,
.multiselect--above.multiselect--active .multiselect__tags {
    border-top-left-radius  : 0;
    border-top-right-radius : 0;
}

.multiselect__input,
.multiselect__single {
    position       : relative;
    display        : inline-block;
    min-height     : $vue-multiselect-min-height / 2;
    line-height    : $vue-multiselect-line-height;
    border         : none;
    border-radius  : $vue-multiselect-border-radius;
    background     : $vue-multiselect-bg;
    padding        : 0;
    width          : calc(100%);
    transition     : border 0.1s ease;
    box-sizing     : border-box;
    margin-bottom  : $vue-multiselect-padding-y;
    vertical-align : top;
}

.multiselect__input::placeholder {
    color : $vue-multiselect-placeholder-color;
}

.multiselect__tag ~ .multiselect__input,
.multiselect__tag ~ .multiselect__single {
    width : auto;
}

.multiselect__input:hover,
.multiselect__single:hover {
    border-color : #cfcfcf;
}

.multiselect__input:focus,
.multiselect__single:focus {
    border-color : #a8a8a8;
    outline      : none;
}

.multiselect__tags-wrap {
    display : inline
}

.multiselect__tags {
    min-height    : $vue-multiselect-min-height;
    display       : block;
    padding       : $vue-multiselect-padding-y $vue-multiselect-min-height 0 $vue-multiselect-padding-x;
    border-radius : $vue-multiselect-border-radius;
    border        : $vue-multiselect-border-width solid $vue-multiselect-border-color;
    background    : $vue-multiselect-bg;
    font-family   : inherit;
    font-size     : inherit;
}

.multiselect__tag {
  position: relative;
  display: inline-block;
  padding: $vue-multiselect-tag-padding-y ($vue-multiselect-tag-icon-size + $vue-multiselect-tag-padding-x) $vue-multiselect-tag-padding-y $vue-multiselect-tag-padding-x*2;
  border-radius: $vue-multiselect-tag-border-radius;
  margin-right: $vue-multiselect-tag-padding-x;
  color: $vue-multiselect-tag-color;
  line-height: $vue-multiselect-tag-line-height;
  background: $vue-multiselect-tag-bg;
  white-space: nowrap;
  overflow: hidden;
  max-width: 100%;
  text-overflow: ellipsis;
}

.multiselect__tag-icon {
    cursor: pointer;
    border-radius : $vue-multiselect-border-radius;
    margin-left: $vue-multiselect-tag-padding-y;
    position: absolute;
    right: 0;
    top: 0;
    bottom: 0;
    font-style: initial;
    font-weight: $vue-multiselect-tag-font-weight;
    width: $vue-multiselect-tag-icon-size;
    text-align: center;
    line-height: $line-height-base;
    transition: all 0.2s ease;
}

.multiselect__tag-icon:after {
    content   : "×";
    color     : $vue-multiselect-tag-icon-color;
}

.multiselect__tag-icon:focus,
.multiselect__tag-icon:hover {
    background : $vue-multiselect-tag-icon-bg-hover;
}

.multiselect__tag-icon:focus:after,
.multiselect__tag-icon:hover:after {
    color : $vue-multiselect-tag-icon-color-hover;
}

.multiselect__current {
    line-height     : $vue-multiselect-line-height;
    min-height      : $vue-multiselect-min-height;
    box-sizing      : border-box;
    display         : block;
    overflow        : hidden;
    padding         : 8px 30px 0 12px;
    white-space     : nowrap;
    margin          : 0;
    text-decoration : none;
    border-radius   : $vue-multiselect-border-radius;
    border          : 1px solid $vue-multiselect-border-color;
    cursor          : pointer;
}

.multiselect__select {
    line-height     : $vue-multiselect-line-height;
    display         : block;
    position        : absolute;
    box-sizing      : border-box;
    width           : $vue-multiselect-min-height;
    height          : $vue-multiselect-min-height;
    right           : 0;
    top             : 0;
    padding         : ($vue-multiselect-arrow-padding) $vue-multiselect-arrow-padding;
    margin          : 0;
    text-decoration : none;
    text-align      : center;
    cursor          : pointer;
    transition      : transform 0.2s ease;
}

.multiselect__select:before {
    position     : relative;
    right        : 0;
    top          : 50%;
    color        : $vue-multiselect-arrow-color;
    border-style : solid;
    border-width : $vue-multiselect-arrow-size $vue-multiselect-arrow-size 0 $vue-multiselect-arrow-size;
    border-color : $vue-multiselect-arrow-color transparent transparent transparent;
    content      : "";
}

.multiselect__placeholder {
    color         : $vue-multiselect-placeholder-color;
    display       : inline-block;
    margin-bottom : 10px;
    padding-top   : 2px;
}

.multiselect--active .multiselect__placeholder {
    display : none;
}

.multiselect__content-wrapper {
    position                   : absolute;
    display                    : block;
    background                 : $vue-multiselect-bg;
    width                      : auto;
    min-width                  : 100%;
    max-height                 : 240px;
    overflow-x                 : hidden;
    overflow-y                 : auto;
    border                     : $vue-multiselect-border-width solid $vue-multiselect-border-color;
    border-top                 : none;
    border-bottom-left-radius  : $vue-multiselect-border-radius;
    border-bottom-right-radius : $vue-multiselect-border-radius;
    z-index                    : 50;
    -webkit-overflow-scrolling : touch;
}

.multiselect__content {
    list-style     : none;
    display        : inline-block;
    padding        : 0;
    margin         : 0;
    min-width      : 100%;
    vertical-align : top;
}

.multiselect--above .multiselect__content-wrapper {
    bottom        : 100%;
    border-radius : $vue-multiselect-border-radius $vue-multiselect-border-radius 0 0;
    border-bottom : none;
    border-top    : $vue-multiselect-border-width solid $vue-multiselect-border-color;
}

.multiselect__content::webkit-scrollbar {
    display : none;
}

.multiselect__element {
    display : block;
}

.multiselect__option {
    display         : block;
    padding         : $vue-multiselect-padding-y $vue-multiselect-padding-x;
    min-height      : $vue-multiselect-min-height;
    line-height     : $vue-multiselect-line-height;
    text-decoration : none;
    text-transform  : none;
    vertical-align  : middle;
    position        : relative;
    cursor          : pointer;
    white-space     : nowrap;
}

.multiselect__option:after {
    top           : 0;
    right         : 0;
    position      : absolute;
    line-height   : $vue-multiselect-min-height;
    padding-right : 12px;
    padding-left  : 20px;
    font-family   : inherit;
    font-size     : inherit;
}

.multiselect__option--highlight {
    background : $vue-multiselect-option-highlight-bg;
    outline    : none;
    color      : $vue-multiselect-option-highlight-color;
}

.multiselect__option--highlight:after {
    content    : attr(data-select);
    background : $vue-multiselect-option-highlight-bg;
    color      : $vue-multiselect-option-highlight-color;
}

.multiselect__option--selected {
    background  : $vue-multiselect-option-selected-bg;
    color       : $vue-multiselect-option-selected-color;
    font-weight : bold;
}

.multiselect__option--selected:after {
    content : attr(data-selected);
    color   : silver;
}

.multiselect__option--selected.multiselect__option--highlight {
    background : $vue-multiselect-option-selected-highlight-bg;
    color      : $vue-multiselect-option-selected-highlight-color;
}

.multiselect__option--selected.multiselect__option--highlight:after {
    background : $vue-multiselect-option-selected-highlight-bg;
    content    : attr(data-deselect);
    color      : $vue-multiselect-option-selected-highlight-color;
}

.multiselect--disabled {
    background     : $vue-multiselect-disabled-bg;
    pointer-events : none;
}

.multiselect--disabled .multiselect__current,
.multiselect--disabled .multiselect__select {
    background : $vue-multiselect-disabled-bg;
    color      : $vue-multiselect-disabled-color;
}

.multiselect__option--disabled {
    background     : $vue-multiselect-disabled-bg;
    color          : $vue-multiselect-disabled-color;
    cursor         : text;
    pointer-events : none;
}

.multiselect__option--group {
    background : $vue-multiselect-disabled-bg;
    color      : $vue-multiselect-disabled-color;

    &.multiselect__option--highlight {
        background : $vue-multiselect-disabled-color;
        color      : $vue-multiselect-disabled-bg;
    }

    &.multiselect__option--highlight:after {
        background : $vue-multiselect-disabled-color;
    }
}

.multiselect__option--disabled.multiselect__option--highlight {
    background : $vue-multiselect-disabled-bg;
}

.multiselect__option--group-selected.multiselect__option--highlight {
    background : $vue-multiselect-option-selected-highlight-bg;
    color      : $vue-multiselect-option-selected-highlight-color;
}

.multiselect__option--group-selected.multiselect__option--highlight:after {
    background : $vue-multiselect-option-selected-highlight-bg;
    content    : attr(data-deselect);
    color      : $vue-multiselect-option-selected-highlight-color;
}

.multiselect-enter-active,
.multiselect-leave-active {
    transition : all 0.15s ease;
}

.multiselect-enter,
.multiselect-leave-active {
    opacity : 0;
}

.multiselect__strong {
    margin-bottom  : $vue-multiselect-padding-y;
    line-height    : $vue-multiselect-line-height;
    display        : inline-block;
    vertical-align : top;
}

// --------------------------------
// Spinner
//--

.multiselect__spinner {
    position   : absolute;
    right      : 0;
    top        : 0;
    width      : $vue-multiselect-min-height;
    height     : $vue-multiselect-min-height;
    background : $vue-multiselect-bg;
    display    : block;

    &:before,
    &:after {
        position         : absolute;
        content          : "";
        top              : 50%;
        left             : 50%;
        margin           : $vue-multiselect-spinner-margin 0 0 $vue-multiselect-spinner-margin;
        width            : $vue-multiselect-spinner-size;
        height           : $vue-multiselect-spinner-size;
        border-radius    : 100%;
        border           : $vue-multiselect-spinner-thickness solid transparent;
        border-top-color : $vue-multiselect-spinner-color;
        box-shadow       : 0 0 0 1px transparent;
    }

    &:before {
        animation                 : spinning 2.4s cubic-bezier(0.41, 0.26, 0.2, 0.62);
        animation-iteration-count : infinite;
    }

    &:after {
        animation                 : spinning 2.4s cubic-bezier(0.51, 0.09, 0.21, 0.8);
        animation-iteration-count : infinite;
    }
}

@keyframes spinning {
    from {
        transform : rotate(0)
    }
    to {
        transform : rotate(2turn)
    }
}

// --------------------------------
// Loading state
//--

.multiselect__loading-enter-active,
.multiselect__loading-leave-active {
    transition : opacity 0.4s ease-in-out;
    opacity    : 1;
}

.multiselect__loading-enter,
.multiselect__loading-leave-active {
    opacity : 0;
}

// --------------------------------
// RTL adjustments
//--

*[dir="rtl"] {
    .multiselect {
        text-align : right;
    }
    .multiselect__select {
        right : auto;
        left  : 1px;
    }
    .multiselect__tags {
        padding : $vue-multiselect-padding-y $vue-multiselect-padding-y 0 $vue-multiselect-min-height;
    }
    .multiselect__content {
        text-align : right;
    }
    .multiselect__option:after {
        right : auto;
        left  : 0;
    }
    .multiselect__clear {
        right : auto;
        left  : 12px;
    }
    .multiselect__spinner {
        right : auto;
        left  : 1px;
    }
}

The _settings/variables_ that I import is just a small file made up of a couple of helper variables as follows:

@import "../libs/bootstrap-sass/bootstrap/variables";

$brand-secondary: darken($brand-primary, 7.5%) !default;
$brand-dark: darken($brand-primary, 30%) !default;
$brand-light: lighten($brand-primary, 51.5%) !default;

[vahidalvandi]

please add support bootstrap 4

[shentao]

This should be much easier to do in v3 release, since you will be able to ditch all the tags (and classes) and provide your own template that can use Bootstrap classes. However, no plans to introduce Bootstrap support for v2. Sorry.

[cichy380]

@vpratfr in your code is missing part for .multiselect__clear

[lecano]

If someone is having this weird height effect when using a placeholder

Use this fix:
.multiselect__placeholder { color: $vue-multiselect-placeholder-color; display: inline-block; margin-bottom: 0px; padding-top: 0px; }

• add margin-left: 12px; to fix placeholder text

[ArthurShlain]

Bootstrap is-invalid class not working by default.
Need something like this:

@import "../../../sass/variables"; // your own variables for bootstrap

@import "~bootstrap/scss/functions";
@import "~bootstrap/scss/mixins";
@import "~bootstrap/scss/variables"; // default bootstrap variables

// another vue-multiselect bootstrap styles

.multiselect.is-invalid {
  .multiselect-tags {
    border-color: $form-feedback-invalid-color;
  }
}

I dont know how to check custom styles compatibility on vue-multiselect updates.

[loeffel-io]

Simple and small solution for multiple=false:

@import "~bootstrap/scss/variables";

.multiselect {
  color: $input-color;

  .multiselect__tags {
    border-color: $input-border-color;
    border-radius: $input-border-radius;
    padding: $input-padding-y $input-padding-x;
    font-size: $input-font-size;

    .multiselect__placeholder {
      margin-bottom: 0;
      color: $input-placeholder-color;
      padding: 0;
    }

    .multiselect__input, .multiselect__single {
      line-height: $input-line-height;
      padding: 0;
      margin-bottom: 0;
    }
  }

  .multiselect__option--highlight {
    background-color: $primary;
  }
}

[mathieutu]

Hi folks,
This is an updated version from all comments here, and with native select bootstrap state handling.

It's made and tested for a single value select (with autocompletion):

<style lang="scss">

@import "~bootstrap/scss/functions";
@import "~bootstrap/scss/variables";

$vue-multiselect-padding-x: $custom-select-padding-x !default;
$vue-multiselect-padding-y: $custom-select-padding-y !default;
$vue-multiselect-min-height: $custom-select-height !default;
$vue-multiselect-border-radius: $border-radius !default;
$vue-multiselect-border-color: $custom-select-border-color !default;
$vue-multiselect-border-width: 1px !default;
$vue-multiselect-disabled-opacity: $btn-disabled-opacity !default;
$vue-multiselect-placeholder-color: $text-muted !default;
$vue-multiselect-bg: $custom-select-bg !default;
$vue-multiselect-color: $custom-select-color !default;
$vue-multiselect-disabled-bg: $custom-select-disabled-bg !default;
$vue-multiselect-disabled-color: $custom-select-disabled-color !default;

$vue-multiselect-option-selected-bg: #f3f3f3 !default;
$vue-multiselect-option-selected-color: $body-color !default;
$vue-multiselect-option-highlight-color: #fff !default;
$vue-multiselect-option-highlight-bg: theme-color("primary") !default;
$vue-multiselect-option-selected-highlight-color: #fff !default;
$vue-multiselect-option-selected-highlight-bg: theme-color("secondary") !default;

$vue-multiselect-tag-color: $dark !default;
$vue-multiselect-tag-bg: $light !default;
$vue-multiselect-tag-font-size: $badge-font-size !default;
$vue-multiselect-tag-font-weight: normal !default;
$vue-multiselect-tag-icon-size: 1.7rem !default;
$vue-multiselect-tag-icon-color: $vue-multiselect-tag-color !default;
$vue-multiselect-tag-icon-color-hover: white !default;
$vue-multiselect-tag-icon-bg-hover: $danger !default;
$vue-multiselect-tag-padding-x: .4rem !default;
$vue-multiselect-tag-padding-y: .25rem !default;
$vue-multiselect-tag-border-radius: $badge-border-radius !default;

$vue-multiselect-arrow-color: $custom-select-color !default;
$vue-multiselect-arrow-size: 5px !default;
$vue-multiselect-arrow-padding: 8px !default;

$vue-multiselect-spinner-size: 16px !default;
$vue-multiselect-spinner-thickness: 2px !default;
$vue-multiselect-spinner-margin: -$vue-multiselect-spinner-size/2 !default;
$vue-multiselect-spinner-color: $dark !default;

// --------------------------------
// Select field
//--

fieldset[disabled] .multiselect {
  pointer-events: none;
}

.multiselect,
.multiselect__input,
.multiselect__single {
  font-family: inherit;
  font-size: inherit;
  touch-action: manipulation;
}

.multiselect {
  box-sizing: content-box;
  display: block;
  position: relative;
  width: 100%;
  min-height: $vue-multiselect-min-height;
  text-align: left;
  color: $vue-multiselect-color;

  & * {
    box-sizing: border-box;
  }

  &:focus {
    outline: none;
  }
}

.multiselect--disabled {
  pointer-events: none;
  opacity: $vue-multiselect-disabled-opacity;
}

.multiselect--active {
  z-index: 50;

  &:not(.multiselect--above) .multiselect__current,
  &:not(.multiselect--above) .multiselect__input,
  &:not(.multiselect--above) .multiselect__tags {
    border-bottom-left-radius: 0;
    border-bottom-right-radius: 0;
  }

  & .multiselect__select {
    transform: rotateZ(180deg);
  }
}

.multiselect--above.multiselect--active .multiselect__current,
.multiselect--above.multiselect--active .multiselect__input,
.multiselect--above.multiselect--active .multiselect__tags {
  border-top-left-radius: 0;
  border-top-right-radius: 0;
}

.multiselect__input,
.multiselect__single {
  position: relative;
  display: inline-block;
  min-height: $vue-multiselect-min-height / 2;
  line-height: $vue-multiselect-min-height / 2;
  border: none;
  border-radius: $vue-multiselect-border-radius;
  background: $vue-multiselect-bg;
  padding: 0 0 0 $vue-multiselect-padding-x;
  width: calc(100%);
  transition: border 0.1s ease;
  box-sizing: border-box;
  margin-bottom: $vue-multiselect-padding-y;
  vertical-align: top;
}

.multiselect__input::placeholder {
  color: $vue-multiselect-placeholder-color;
}

.multiselect__tag ~ .multiselect__input,
.multiselect__tag ~ .multiselect__single {
  width: auto;
}

.multiselect__input:hover,
.multiselect__single:hover {
  border-color: #cfcfcf;
}

.multiselect__input:focus,
.multiselect__single:focus {
  border-color: #a8a8a8;
  outline: none;
}

.multiselect__single {
  padding-left: $vue-multiselect-padding-x;
  margin-bottom: $vue-multiselect-padding-y;
}

.multiselect__tags-wrap {
  display: inline
}

.multiselect__tags {
  min-height: $vue-multiselect-min-height;
  display: block;
  padding: $vue-multiselect-padding-y $vue-multiselect-min-height 0 $vue-multiselect-padding-y;
  border-radius: $vue-multiselect-border-radius;
  border: $vue-multiselect-border-width solid $vue-multiselect-border-color;
  background: $vue-multiselect-bg;
  font-family: inherit;
  font-size: inherit;
}

.multiselect__tag {
  position: relative;
  display: inline-block;
  padding: $vue-multiselect-tag-padding-y ($vue-multiselect-tag-icon-size + $vue-multiselect-tag-padding-x) $vue-multiselect-tag-padding-y $vue-multiselect-tag-padding-x;
  border-radius: $vue-multiselect-tag-border-radius;
  margin-right: $vue-multiselect-tag-padding-x;
  color: $vue-multiselect-tag-color;
  background: $vue-multiselect-tag-bg;
  white-space: nowrap;
  overflow: hidden;
  max-width: 100%;
  text-overflow: ellipsis;
  font-size: $vue-multiselect-tag-font-size;
  font-weight: $vue-multiselect-tag-font-weight;
}

.multiselect__tag-icon {
  cursor: pointer;
  margin-left: $vue-multiselect-tag-padding-y;
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  font-style: initial;
  width: $vue-multiselect-tag-icon-size;
  text-align: center;
  line-height: $vue-multiselect-tag-icon-size;
  transition: all 0.2s ease;
  font-size: $vue-multiselect-tag-font-size;
  font-weight: $vue-multiselect-tag-font-weight;
}

.multiselect__tag-icon:after {
  content: "×";
  color: $vue-multiselect-tag-icon-color;
  font-size: 220%;
}

.multiselect__tag-icon:focus,
.multiselect__tag-icon:hover {
  background: $vue-multiselect-tag-icon-bg-hover;
}

.multiselect__tag-icon:focus:after,
.multiselect__tag-icon:hover:after {
  color: $vue-multiselect-tag-icon-color-hover;
}

.multiselect__current {
  line-height: $vue-multiselect-min-height / 2;
  min-height: $vue-multiselect-min-height;
  box-sizing: border-box;
  display: block;
  overflow: hidden;
  padding: 8px 30px 0 12px;
  white-space: nowrap;
  margin: 0;
  text-decoration: none;
  border-radius: $vue-multiselect-border-radius;
  border: 1px solid $vue-multiselect-border-color;
  cursor: pointer;
}

.multiselect__select {
  line-height: $vue-multiselect-min-height / 2;
  display: block;
  position: absolute;
  box-sizing: border-box;
  width: $vue-multiselect-min-height;
  height: $vue-multiselect-min-height;
  right: 0;
  top: 0;
  padding: ($vue-multiselect-arrow-padding) $vue-multiselect-arrow-padding;
  margin: 0;
  text-decoration: none;
  text-align: center;
  cursor: pointer;
  transition: transform 0.2s ease;
}

.multiselect__select:before {
  position: relative;
  right: 0;
  top: 50%;
  color: $vue-multiselect-arrow-color;
  border-style: solid;
  border-width: $vue-multiselect-arrow-size $vue-multiselect-arrow-size 0 $vue-multiselect-arrow-size;
  border-color: $vue-multiselect-arrow-color transparent transparent transparent;
  content: "";
}

.multiselect__placeholder {
  color: $vue-multiselect-placeholder-color;
  display: inline-block;
  margin-bottom: 10px;
  padding-top: 2px;
}

.multiselect--active .multiselect__placeholder {
  display: none;
}

.multiselect__content-wrapper {
  position: absolute;
  display: block;
  background: $vue-multiselect-bg;
  width: 100%;
  max-height: 240px;
  overflow: auto;
  border: $vue-multiselect-border-width solid $vue-multiselect-border-color;
  border-top: none;
  border-bottom-left-radius: $vue-multiselect-border-radius;
  border-bottom-right-radius: $vue-multiselect-border-radius;
  z-index: 50;
  -webkit-overflow-scrolling: touch;
}

.multiselect__content {
  list-style: none;
  display: inline-block;
  padding: 0;
  margin: 0;
  min-width: 100%;
  vertical-align: top;
}

.multiselect--above .multiselect__content-wrapper {
  bottom: 100%;
  border-radius: $vue-multiselect-border-radius $vue-multiselect-border-radius 0 0;
  border-bottom: none;
  border-top: $vue-multiselect-border-width solid $vue-multiselect-border-color;
}

.multiselect__content::webkit-scrollbar {
  display: none;
}

.multiselect__element {
  display: block;
}

.multiselect__option {
  display: block;
  padding: $vue-multiselect-padding-y $vue-multiselect-padding-x;
  min-height: $vue-multiselect-min-height;
  line-height: $vue-multiselect-min-height / 2;
  text-decoration: none;
  text-transform: none;
  vertical-align: middle;
  position: relative;
  cursor: pointer;
  white-space: nowrap;
}

.multiselect__option:after {
  top: 0;
  right: 0;
  position: absolute;
  line-height: $vue-multiselect-min-height;
  padding-right: 12px;
  padding-left: 20px;
  font-family: inherit;
  font-size: inherit;
}

.multiselect__option--highlight {
  background: $vue-multiselect-option-highlight-bg;
  outline: none;
  color: $vue-multiselect-option-highlight-color;
}

.multiselect__option--highlight:after {
  content: attr(data-select);
  background: $vue-multiselect-option-highlight-bg;
  color: $vue-multiselect-option-highlight-color;
}

.multiselect__option--selected {
  background: $vue-multiselect-option-selected-bg;
  color: $vue-multiselect-option-selected-color;
  font-weight: bold;
}

.multiselect__option--selected:after {
  content: attr(data-selected);
  color: silver;
}

.multiselect__option--selected.multiselect__option--highlight {
  background: $vue-multiselect-option-selected-highlight-bg;
  color: $vue-multiselect-option-selected-highlight-color;
}

.multiselect__option--selected.multiselect__option--highlight:after {
  background: $vue-multiselect-option-selected-highlight-bg;
  content: attr(data-deselect);
  color: $vue-multiselect-option-selected-highlight-color;
}

.multiselect--disabled {
  background: $vue-multiselect-disabled-bg;
  pointer-events: none;
}

.multiselect--disabled .multiselect__current,
.multiselect--disabled .multiselect__select {
  background: $vue-multiselect-disabled-bg;
  color: $vue-multiselect-disabled-color;
}

.multiselect__option--disabled {
  background: $vue-multiselect-disabled-bg;
  color: $vue-multiselect-disabled-color;
  cursor: text;
  pointer-events: none;
}

.multiselect__option--group {
  background: $vue-multiselect-disabled-bg;
  color: $vue-multiselect-disabled-color;

  &.multiselect__option--highlight {
    background: $vue-multiselect-disabled-color;
    color: $vue-multiselect-disabled-bg;
  }

  &.multiselect__option--highlight:after {
    background: $vue-multiselect-disabled-color;
  }
}

.multiselect__option--disabled.multiselect__option--highlight {
  background: $vue-multiselect-disabled-bg;
}

.multiselect__option--group-selected.multiselect__option--highlight {
  background: $vue-multiselect-option-selected-highlight-bg;
  color: $vue-multiselect-option-selected-highlight-color;
}

.multiselect__option--group-selected.multiselect__option--highlight:after {
  background: $vue-multiselect-option-selected-highlight-bg;
  content: attr(data-deselect);
  color: $vue-multiselect-option-selected-highlight-color;
}

.multiselect-enter-active,
.multiselect-leave-active {
  transition: all 0.15s ease;
}

.multiselect-enter,
.multiselect-leave-active {
  opacity: 0;
}

.multiselect__strong {
  margin-bottom: $vue-multiselect-padding-y;
  line-height: $vue-multiselect-min-height/2;
  display: inline-block;
  vertical-align: top;
}

// --------------------------------
// Spinner
//--

.multiselect__spinner {
  position: absolute;
  right: 0;
  top: 0;
  width: $vue-multiselect-min-height;
  height: $vue-multiselect-min-height;
  display: block;

  &:before,
  &:after {
    position: absolute;
    content: "";
    top: 50%;
    left: 50%;
    margin: $vue-multiselect-spinner-margin 0 0 $vue-multiselect-spinner-margin;
    width: $vue-multiselect-spinner-size;
    height: $vue-multiselect-spinner-size;
    border-radius: 100%;
    border: $vue-multiselect-spinner-thickness solid transparent;
    border-top-color: $vue-multiselect-spinner-color;
    box-shadow: 0 0 0 1px transparent;
    background: $vue-multiselect-bg;
  }

  &:before {
    animation: spinning 2.4s cubic-bezier(0.41, 0.26, 0.2, 0.62);
    animation-iteration-count: infinite;
  }

  &:after {
    animation: spinning 2.4s cubic-bezier(0.51, 0.09, 0.21, 0.8);
    animation-iteration-count: infinite;
  }
}

@keyframes spinning {
  from {
    transform: rotate(0)
  }
  to {
    transform: rotate(2turn)
  }
}

// --------------------------------
// Loading state
//--

.multiselect__loading-enter-active,
.multiselect__loading-leave-active {
  transition: opacity 0.4s ease-in-out;
  opacity: 1;
}

.multiselect__loading-enter,
.multiselect__loading-leave-active {
  opacity: 0;
}

// --------------------------------
// RTL adjustments
//--

*[dir="rtl"] {
  .multiselect {
    text-align: right;
  }

  .multiselect__select {
    right: auto;
    left: 1px;
  }

  .multiselect__tags {
    padding: $vue-multiselect-padding-y $vue-multiselect-padding-y 0 $vue-multiselect-min-height;
  }

  .multiselect__content {
    text-align: right;
  }

  .multiselect__option:after {
    right: auto;
    left: 0;
  }

  .multiselect__clear {
    right: auto;
    left: 12px;
  }

  .multiselect__spinner {
    right: auto;
    left: 1px;
  }
}

// @see https://github.com/shentao/vue-multiselect/issues/718#issuecomment-471195859

.multiselect__placeholder {
  color: $vue-multiselect-placeholder-color;
  display: inline-block;
  margin-bottom: 0;
  padding-top: 0;
  margin-left: 12px;
}

// is-valid / is-invalid state handling
// @see node_modules/bootstrap/scss/_forms.scss:262
@each $state, $data in $form-validation-states {
  $color: map-get($data, color);
  $icon: map-get($data, icon);
  .form-group.is-#{$state} .multiselect__tags {
    border-color: $color;

    @if $enable-validation-icons {
      padding-right: $custom-select-feedback-icon-padding-right;
      background: escape-svg($icon) $custom-select-bg no-repeat $custom-select-feedback-icon-position / $custom-select-feedback-icon-size;
    }

    &:focus {
      border-color: $color;
      box-shadow: 0 0 0 $input-focus-width rgba($color, .25);
    }
  }
}

Thanks for your work on it.

[loeffel-io]

this one works for multiple + single + tags: https://github.com/go-saas/go-saas-ui/blob/master/src/scss/vue-multiselect.scss