Link files in Media library?

Any idea how to link files in the media library?

I’m trying to attach these files to the post/page where they were uploaded and it seems like a first step would be to link them to the media library. Right now they are in a separate folder and invisible to the library.

Any ideas?

I’m trying to use this : http://cube3x.com/2013/03/upload-files-to-wordpress-media-library-using-php/

wp_insert_attachment() and add it in the UploadHandler.php or the plugin php file.

I’m doing something wrong as I get Json errors.

This is the handler: Handler

This is the main php file: Main php

Any help is appreciated

https://wordpress.org/plugins/jquery-html5-file-upload/