[jquery] Get data from file input in JQuery

I actually have a file input and I would like to retrieve the Base64 data of the file.

I tried:

$('input#myInput')[0].files[0] 

to retrieve the data. But it only provides the name, the length, the content type but not the data itself.

I actually need these data to send them to Amazon S3

I already test the API and when I send the data through html form with encode type "multipart/form-data" it works.

I use this plugin : http://jasny.github.com/bootstrap/javascript.html#fileupload

And this plugins gives me a preview of the picture and I retrieve data in the src attribute of the image preview. But when I send these data to S3 it does not work. I maybe need to encode the data like "multipart/form-data" but I don't know why.

Is there a way to retrieve these data without using an html form?

FileReader API with jQuery, simple example.

( function ( $ ) {_x000D_
 // Add click event handler to button_x000D_
 $( '#load-file' ).click( function () {_x000D_
  if ( ! window.FileReader ) {_x000D_
   return alert( 'FileReader API is not supported by your browser.' );_x000D_
  }_x000D_
  var $i = $( '#file' ), // Put file input ID here_x000D_
   input = $i[0]; // Getting the element from jQuery_x000D_
  if ( input.files && input.files[0] ) {_x000D_
   file = input.files[0]; // The file_x000D_
   fr = new FileReader(); // FileReader instance_x000D_
   fr.onload = function () {_x000D_
    // Do stuff on onload, use fr.result for contents of file_x000D_
    $( '#file-content' ).append( $( '<div/>' ).html( fr.result ) )_x000D_
   };_x000D_
   //fr.readAsText( file );_x000D_
   fr.readAsDataURL( file );_x000D_
  } else {_x000D_
   // Handle errors here_x000D_
   alert( "File not selected or browser incompatible." )_x000D_
  }_x000D_
 } );_x000D_
} )( jQuery );

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<input type="file" id="file" />_x000D_
<input type='button' id='load-file' value='Load'>_x000D_
<div id="file-content"></div>

To read as text... uncomment //fr.readAsText(file); line and comment fr.readAsDataURL(file);

 <script src="~/fileupload/fileinput.min.js"></script>
 <link href="~/fileupload/fileinput.min.css" rel="stylesheet" />

Download above files named fileinput add the path i your index page.

<div class="col-sm-9 col-lg-5" style="margin: 0 0 0 8px;">
<input id="uploadFile1" name="file" type="file" class="file-loading"       
 `enter code here`accept=".pdf" multiple>
</div>

<script>
        $("#uploadFile1").fileinput({
            autoReplace: true,
            maxFileCount: 5
        });
</script>

Html:

<input type="file" name="input-file" id="input-file">

jQuery:

var fileToUpload = $('#input-file').prop('files')[0];

We want to get first element only, because prop('files') returns array.

input file element:

<input type="file" id="fileinput" />

get file :

var myFile = $('#fileinput').prop('files');

input element, of type file

<input id="fileInput" type="file" />

On your input change use the FileReader object and read your input file property:

$('#fileInput').on('change', function () {
    var fileReader = new FileReader();
    fileReader.onload = function () {
      var data = fileReader.result;  // data <-- in this var you have the file data in Base64 format
    };
    fileReader.readAsDataURL($('#fileInput').prop('files')[0]);
});

FileReader will load your file and in fileReader.result you have the file data in Base64 format (also the file content-type (MIME), text/plain, image/jpg, etc)

I created a form data object and appended the file:

var form = new FormData(); 
form.append("video", $("#fileInput")[0].files[0]);

and i got:

------WebKitFormBoundaryNczYRonipfsmaBOK
Content-Disposition: form-data; name="video"; filename="Wildlife.wmv"
Content-Type: video/x-ms-wmv

in the headers sent. I can confirm this works because my file was sent and stored in a folder on my server. If you don't know how to use the FormData object there is some documentation online, but not much. Form Data Object Explination by Mozilla