yii2-bootstrap5/docs/guide/migrating-yii2-bootstrap.md

Migrating from yii2-bootstrap4

yii2-bootstrap5 is a major rewrite of the entire project (according Bootstrap 5 to Bootstrap 4 migration guide). The most notable changes are summarized below:

General

• The namespace is yii\bootstrap5 instead of yii\bootstrap4
• The php compatibility is limited to >=7.0
• The close buttons of widgets like yii\bootstrap5\Alert or yii\bootstrap5 now gets rendered via CSS and does not have any content anymore. So be sure to remove btn-close class and set appropriate styles yourself if you override it.

Widgets / Classes

BaseHtml

ActiveField

ActiveForm

There is a new constant yii\bootstrap5\ActiveForm::LAYOUT_FLOATING. It's a new form layout introduced in Bootstrap 5.

Breadcrumbs

ButtonDropdown

ButtonToolbar

Carousel

LinkPager

Modal

data-target and data-toggle change to data-bs-target and data-bs-toggle

Nav

NavBar

There is now the possibility to create an offcanvas navbar. You can achieve this by setting the $collapseOptions to false in yii\bootstrap5\NavBar widget and the $offcanvasOptions to at least an empty array.

Tabs

ToggleButtonGroup