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

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

Tabs

ToggleButtonGroup