Hannes Pries - Web/Shopware/JavaScript-Developer Blog
Weil es immer eine simple Lösung gibt!

docker run -p 2222:22 -d atmoz/sftp foo:pass:::upload

var result=null;
for(var i=0;i<chunks.length;i++){
var last=false;
if(i==(chunks.length-1)){
last=true;
}
result=uploadFileChunk(chunks,filenamePrefix+file.name,url,params,last);
}
return result;

function uploadFileChunk(chunk,filename,url,params,lastChunk) {
var formData = new FormData();
formData.append('upfile', chunk, filename);
formData.append("filename",filename);

for(key in params){
formData.append(key,params[key]);
}

if(lastChunk){
formData.append("lastChunk","true");
}
else{
formData.append("lastChunk","false");
}

var xhr = new XMLHttpRequest();

xhr.open("POST", url,false); //false=synchron;
xhr.send(formData);
console.log("upload response-text: "+xhr.responseText);
return xhr.responseText;
}

function createChunksOfFile(file,chunkSize){
var chunks=new Array();

var filesize=file.size;

var counter=0;
while(filesize>counter){
var chunk=file.slice(counter,(counter+chunkSize));
counter=counter+chunkSize;

chunks[chunks.length]=chunk;
}

return chunks;
}

var chunks=createChunksOfFile(file,250000);

var rotate=parseInt(this.rotate);

if(rotate>0){
if(rotate!=180){
ctx.canvas.width=height;
ctx.canvas.height=width;
}
else{
ctx.canvas.width=width;
ctx.canvas.height=height;
}

ctx.save();
ctx.translate(ctx.canvas.width/2,ctx.canvas.height/2);
ctx.rotate(((Math.PI / 180)*rotate));
ctx.drawImage(this.img.image,0-(width/2),0-(height/2),width,height);
ctx.restore();
}
else{
ctx.canvas.width=width;
ctx.canvas.height=height;
ctx.drawImage(this.img.image,0,0,width,height);
}

var result;
for(var i=0;i<chunks.length;i++){
var last=false;
if(i==(chunks.length-1)){
last=true;
}
result=uploadFileChunk(chunks,filenamePrefix+file.name,url,params,last);
}
return result;

function uploadFileChunk(chunk,filename,url,params,lastChunk) {
var formData = new FormData();
formData.append('upfile', chunk, filename);
formData.append("filename",filename);

for(key in params){
formData.append(key,params[key]);
}

if(lastChunk){
formData.append("lastChunk","true");
}
else{
formData.append("lastChunk","false");
}

var xhr = new XMLHttpRequest();

xhr.open("POST", url,false); //false=synchron;
xhr.send(formData);
console.log("upload response-text: "+xhr.responseText);
return xhr.responseText;
}

var canvas=document.createElement("canvas");
var factor=1;
if($scope.newPostPreviewImage.width>$scope.longestSide){
factor=($scope.newPostPreviewImage.width/$scope.longestSide);
}

canvas.width=$scope.newPostPreviewImage.width/factor;
canvas.height=$scope.newPostPreviewImage.height/factor;
var ctx=canvas.getContext("2d");
ctx.drawImage($scope.newPostPreviewImage,0,0,canvas.width,canvas.height);
blob=dataURItoBlob(canvas.toDataURL("image/jpeg",0.7));

function dataURItoBlob(dataURI) {
// convert base64 to raw binary data held in a string
var byteString = atob(dataURI.split(',')[1]);

// separate out the mime component
var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];

// write the bytes of the string to an ArrayBuffer
var arrayBuffer = new ArrayBuffer(byteString.length);
var _ia = new Uint8Array(arrayBuffer);
for (var i = 0; i < byteString.length; i++) {
_ia = byteString.charCodeAt(i);
}

var dataView = new DataView(arrayBuffer);
var blob = new Blob([dataView], { type: mimeString });
return blob;
}

$scope.openFile=function(event){
var files=event.target.files;
if(files.length>0 && (files[0].type.match('image.*') || files[0].type.match('image/*'))){
console.log("load file: "+files[0].name);
$scope.newPostFile=files[0];

$scope.newPostPreviewImage=document.createElement("img");
var URL = window.URL || window.webkitURL;
var imgURL = URL.createObjectURL($scope.newPostFile);
$scope.newPostPreviewImage.src=imgURL;

URL.revokeObjectURL(imgURL);

var reader = new FileReader();
reader.onload=function(e){
$scope.newPostPreviewURL=e.target.result;
console.log("add preview image");

try{
$scope.$apply();
}
catch(e){

}
};
reader.readAsDataURL($scope.newPostFile);
}
};

<img ng-src=""/>