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|Alert]] or [[yii\bootstrap5|Modal|Modal]] 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](https://getbootstrap.com/docs/5.1/forms/floating-labels/) introduced in Bootstrap 5. ### Breadcrumbs ### ButtonDropdown ### ButtonToolbar ### Carousel ### LinkPager ### Modal Change `data-target` and `data-toggle` to `data-bs-target` and `data-bs-toggle` ### Nav ### NavBar There is now the possibility to create an [offcanvas navbar](https://getbootstrap.com/docs/5.1/components/navbar/#offcanvas). You can achieve this by setting the `$collapseOptions` to `false` in [[yii\bootstrap5\NavBar|Navbar]] widget and the `$offcanvasOptions` to at least an empty array. ### Tabs ### ToggleButtonGroup