im not a developer in yii2 and i want to enable upload files like php
i want to upload just files like image and pdf doc …
i tried this code but nothing happend : ```
[[‘file’], ‘file’, ‘extensions’ => ‘gif, jpg’],
maybe cause i dont where to put it , any way i think the upload is via ajax , so any help ?
thankshelp me please i can loose my job 
Give us some code of your controller, model and view
i think this is the view
<div class="row">
<div class="col-lg-12">
<div class="caption-desc font-grey-cascade">
<?= Yii::t('app', 'Allowed types {pdf}, {png}, {jpg}. Maximun size {maxsize}',
[
'pdf' => '<pre class="mt-code">pdf</pre>',
'png' => '<pre class="mt-code">png</pre>',
'jpg' => '<pre class="mt-code">jpg</pre>',
'maxsize'=> '<pre class="mt-code">3 MB</pre>'
]);
?>
</div>
</div>
</div>
<div style="margin-top:20px"></div>
<div class="row" id="form-attachment">
<div class="col-lg-12">
<?= backend\widgets\SelectFile::widget(
[
'id' => 'attachment',
'selectText'=> Yii::t('app','Select file'),
'changeText'=> Yii::t('app','Change'),
'removeText'=> Yii::t('app','Remove'),
'uploadText'=> Yii::t('app','Upload')
]); ?>
</div>
</div>
<div class="row" style="display: none" id="msg-upload"></div>
<div style="margin-top:10px"></div>
<div class="row">
<div class="col-lg-12">
<?php yii\widgets\Pjax::begin(
[
'id' => 'pjax-attachments-'.$UserId,
'timeout' => 999999999,
'enableReplaceState'=>false,
'enablePushState'=> false
]); ?>
<?=
\common\widgets\GridView::widget([
'id' => 'grid-'.$UserId,
'dataProvider' => $dataProvider,
'layout' => "{items}\n{pager}",
'columns' => [
[
'label' => Yii::t('app','File name'),
'value' => function($data){
return $data->name;
}
],
[
'label' => Yii::t('app','Upload date'),
'value' => function($data){
return \Yii::$app->formatter->asDate($data->date);
}
],
[
'format'=> 'raw',
'label' => Yii::t('app','Actions'),
'value' => function($data) use ($companyId){
$url = $data->getWebPath($companyId);
return '<a data-pjax="0" target="_blank" id="'.$data->id.'" href="http://'.$url.'"><i class="material-icons left">visibility</i></a>';
}
]
]
]);
?>
<?php yii\widgets\Pjax::end(); ?>
</div>
</div>
<?php
$js = <<<JS
$('#btn-attachment-upload').click(function(){
$('div#msg-upload').html('').hide();
var files = $('#attachment input[type="file"]')[0].files[0];
if( files != undefined ){
var formData= new FormData();
formData.append('files',files);
formData.append('User_id', $UserId);
$.ajax({
type: 'post',
url: '/users/attatchment',
data: formData,
cache: false,
contentType: false,
processData: false,
dataType: 'json',
}).done( function( result ){
var resultUpload = '<div class="col-lg-6">';
if( result.status == 'success' ){
resultUpload += '<div class="alert alert-success">';
resultUpload += '<i class="fa fa-check" aria-hidden="true"></i> ';
$('#form-attachment .fileinput').removeClass('fileinput-exists').addClass('fileinput-new')
$('#form-attachment .fileinput-filename').html('')
$('#attachment input[type="file"]').replaceWith($('#attachment input[type="file"]').val('').clone(true)).trigger('change')
$('.nav-tabs a[href="#attachment"]').trigger('shown.bs.tab');
}else{
resultUpload += '<div class="alert alert-danger">';
resultUpload += '<i class="fa fa-info" aria-hidden="true"></i> ';
}
resultUpload += result.msg+'</div></div>';
$('div#msg-upload').html(resultUpload).show();
})
}
});
$('#attachment input[type="file"]').change(function(){
$('div#msg-upload').html('').hide();
});
JS;
$this->registerJs($js);