<?php
use dosamigos\fileupload\FileUpload;

// without UI
?>

<?= FileUpload::widget([
    'model' => $model,
    'attribute' => 'image',
    'url' => ['media/upload', 'id' => $model->id], // your url, this is just for demo purposes,
    'options' => ['accept' => 'image/*'],
    'clientOptions' => [
        'maxFileSize' => 2000000
    ],
    // Also, you can specify jQuery-File-Upload events
    // see: https://github.com/blueimp/jQuery-File-Upload/wiki/Options#processing-callback-options
    'clientEvents' => [
        'fileuploaddone' => 'function(e, data) {
                                console.log(e);
                                console.log(data);
                            }',
        'fileuploadfail' => 'function(e, data) {
                                console.log(e);
                                console.log(data);
                            }',
    ],
]); ?>

<?php
use dosamigos\fileupload\FileUploadUI;

// with UI
?>
<?= FileUploadUI::widget([
    'model' => $model,
    'attribute' => 'image',
    'url' => ['media/upload', 'id' => $tour_id],
    'gallery' => false,
    'fieldOptions' => [
        'accept' => 'image/*'
    ],
    'clientOptions' => [
        'maxFileSize' => 2000000
    ],
    // ...
    'clientEvents' => [
        'fileuploaddone' => 'function(e, data) {
                                console.log(e);
                                console.log(data);
                            }',
        'fileuploadfail' => 'function(e, data) {
                                console.log(e);
                                console.log(data);
                            }',
    ],
]); ?>

<?php

// action examples

public function actionImageUpload()
{
    $model = new WhateverYourModel();

    $imageFile = UploadedFile::getInstance($model, 'image');

    $directory = Yii::getAlias('@frontend/web/img/temp') . DIRECTORY_SEPARATOR . Yii::$app->session->id . DIRECTORY_SEPARATOR;
    if (!is_dir($directory)) {
        FileHelper::createDirectory($directory);
    }

    if ($imageFile) {
        $uid = uniqid(time(), true);
        $fileName = $uid . '.' . $imageFile->extension;
        $filePath = $directory . $fileName;
        if ($imageFile->saveAs($filePath)) {
            $path = '/img/temp/' . Yii::$app->session->id . DIRECTORY_SEPARATOR . $fileName;
            return Json::encode([
                'files' => [
                    [
                        'name' => $fileName,
                        'size' => $imageFile->size,
                        'url' => $path,
                        'thumbnailUrl' => $path,
                        'deleteUrl' => 'image-delete?name=' . $fileName,
                        'deleteType' => 'POST',
                    ],
                ],
            ]);
        }
    }

    return '';
}

public function actionImageDelete($name)
{
    $directory = Yii::getAlias('@frontend/web/img/temp') . DIRECTORY_SEPARATOR . Yii::$app->session->id;
    if (is_file($directory . DIRECTORY_SEPARATOR . $name)) {
        unlink($directory . DIRECTORY_SEPARATOR . $name);
    }

    $files = FileHelper::findFiles($directory);
    $output = [];
    foreach ($files as $file) {
        $fileName = basename($file);
        $path = '/img/temp/' . Yii::$app->session->id . DIRECTORY_SEPARATOR . $fileName;
        $output['files'][] = [
            'name' => $fileName,
            'size' => filesize($file),
            'url' => $path,
            'thumbnailUrl' => $path,
            'deleteUrl' => 'image-delete?name=' . $fileName,
            'deleteType' => 'POST',
        ];
    }
    return Json::encode($output);
}