Yii 2 GridView Link Not Working

I have this code in my index.php in my view:

<p>
    <?= Html::a('Create Invoice', ['create'], ['class' => 'btn btn-success']) ?>
</p>

<?= GridView::widget([
    'dataProvider' => $dataProvider,
    'filterModel' => $searchModel,
    'columns' => [
        ['class' => 'yii\grid\SerialColumn'],    
        //'inv_id',
        'cust_name',
        'currency',
        'inv_date',
        'inv_duedate',
        'prod_name',
        //'prod_desc',
        //'prod_quanity',
        'prod_price',
        //'prod_tax',
        //'amount',
        //'subtotal',
        'total',
        [
            'attribute' => 'image',
            'format' => 'raw',
            'value' => function($data){
                //return Html::a($data->image, $data->image, $data->image);
                return Html::a(Html::encode($data->image),$data->image);
                //return Html::a($data->image, $data->image, array('target' => '_blank')); 
                //return Html::a(Html::encode('file'),'invoice/index');
            }
        ],
        //'poso_num',
        //'subheading',
        //'footer',
        //'memo',

        ['class' => 'yii\grid\ActionColumn'],
    ],
]); ?>

I have already displayed the link/path of a specific file, when I click it, nothing happens. When I hover it, I can see the link, example: file:///C:/wamp3/www/basicaccounting/web/pdf/attachment.pdf, in the status bar (lower left corner of the page). I also tried right click + Open in New Tab, the url is just about:blank.

I also tried each of those commented return statements, still the same results.

Any thoughts about this?

Edit:

My problem is with my file path i.e. file:///C:/wamp3/www/basicaccounting/web/pdf/attachment.pdf My path in the link needs to be relative to the document root i.e. /basicaccounting/web/pdf/attachment.pdf, and not in C drive.

So I tried:

'value' => function($data){
    $basepath = str_replace('\\', '/', Yii::$app->basePath).'/web/';
    $path = str_replace($basepath, '', $data->file);
    return Html::a($data->file, $path, array('target'=>'_blank'));
}

Now it works fine.

I think I have solved my own problem.

My problem is with my file path i.e. file:///C:/wamp3/www/basicaccounting/web/pdf/attachment.pdf My path in the link needs to be relative to the document root i.e. /basicaccounting/web/pdf/attachment.pdf, and not in C drive.

So I tried:

'value' => function($data){
$basepath = str_replace('\\', '/', Yii::$app->basePath).'/web/';
$path = str_replace($basepath, '', $data->file);
return Html::a($data->file, $path, array('target'=>'_blank'));

Now it works fine. Thanks everyone!