Blob In FormData Is Null

I'm trying to send created photo in android via ajax via remote API. I'm using Camera Picture Background plugin. Photo is created properly, I'm getting it via ajax GET request and

Solution 1:

I've not done this recently, but this works with me. I hope it also works with you:

function getBase64ImageByURL(url) {
  var dfd = new $.Deferred();
  var xhr = new XMLHttpRequest();
  xhr.responseType = 'blob';
  xhr.onload = function() {
    var reader = new FileReader();
    reader.onloadend = function() {
      dfd.resolve(reader.result);
    }
    reader.readAsDataURL(xhr.response);
  };
  xhr.open('GET', url);
  xhr.send();
  return dfd.promise();
}

function base64ToBlob(base64Image,toMimeType) {
  var byteCharacters = atob(base64Image.replace('data:'+toMimeType+';base64,',''));
  var byteNumbers = new Array(byteCharacters.length);
  for (var i = 0; i < byteCharacters.length; i++) {
    byteNumbers[i] = byteCharacters.charCodeAt(i);
  }
  var byteArray = new Uint8Array(byteNumbers);
  var blob = new Blob([byteArray], {
    type: toMimeType
  });
  return blob;
}



var imageUrl = "https://upload.wikimedia.org/wikipedia/commons/4/49/Koala_climbing_tree.jpg";

getBase64ImageByURL(imageUrl).then(function(base64Image){
  var blob = base64ToBlob(base64Image,'image/jpeg');
  var fd = new FormData();
  fd.append('file', blob, 'my_image.jpg');
  $.ajax({
    url: 'http://your_host/uploads/testupload.php',
    data: fd,
    type: 'POST',
    contentType: false,
    processData: false,
    success:function(res){
      console.log(res);
    },
    error:function(err){
      console.log(err);
    }
  })
});

On server-side(testupload.php):

<?php

    if ( 0 < $_FILES['file']['error'] ) {
        echo 'Error: ' . $_FILES['file']['error'] . '<br>';
    }
    else {
        $result = move_uploaded_file($_FILES['file']['tmp_name'], $_SERVER["DOCUMENT_ROOT"].$_SERVER["BASE"].'/uploads/'.'my_image.jpg');
        var_dump("image uploaded: ".$result);
    }

?>

It might be necessary to modify some read/write-permissions on a directory before move_uploaded_file succeeds in moving the uploaded image to this directory.

The function getBase64ImageByURL could already return a blob-object but by returning a base64-image you can show an user this image in a html-image-tag before uploading it for instance.

---

If there is no need to show an user that image, then you can also shorten all steps:

function getBlobImageByURL(url) {
  var dfd = new $.Deferred();
  var xhr = new XMLHttpRequest();
  xhr.responseType = 'blob';
  xhr.onload = function() {
    dfd.resolve(xhr.response);
  };
  xhr.open('GET', url);
  xhr.send();
  return dfd.promise();
}

getBlobImageByURL(imageUrl).then(function(imageBlob){
  var fd = new FormData();
  fd.append('file', imageBlob, 'my_image.jpg');
  console.log(fd.get('file'));// File-object 
  $.ajax({
    url: 'http://your_host/uploads/testupload.php',
    data: fd,
    type: 'POST',
    contentType: false,
    processData: false,
    success:function(res){
      console.log(res);
    },
    error:function(err){
      console.log(err);
    }
  })
});

references to both modified functions base64ToBlob and getBase64ImageByURL