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

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