frontend/widgets/views/search_view.php

<?php
    /**
     * User: timur
     * Date: 28.01.18
     * Time: 12:38
     *
     * @var string $route
     * @var string $paramForSearch
     *
     */
    
    use yii\widgets\ActiveForm;
    use yii\helpers\Html;
?>
<div class="panel panel-default sidebar-menu">
    
    <div class="panel-heading">
        <h3 class="panel-title">Поиск</h3>
    </div>
    
    <div class="panel-body">
        
        <?php
            $form = ActiveForm::begin(
                [
                    'action' => \yii\helpers\Url::toRoute($route),
                    'options' => [
                        'role' => "search",
                    ],
                ]
            );
    
            echo Html::tag(
                "div",
                Html::input(
                    "text",
                    $paramForSearch,
                    null,
                    [
                        'class'       => "form-control",
                        'placeholder' => Yii::t("app", "Search"),
                    ]
                ) . Html::tag(
                    "span",
                    Html::button(
                        "<i class=\"fa fa-search\"></i>",
                        [
                            'class' => "btn btn-template-main",
                            'type'  => "submit",
                        ]
                    ),
                    [
                        'class' => "input-group-btn",
                    ]
                )
        
                ,
                [
                    'class' => "input-group",
                ]
            );
            
            $form::end();
            
        ?>
        
    </div>
</div>