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Load external JSON data via API into PDF file form field

I have a button inside a PDF file which when clicked should call an API and write the data into a form field. Inside the Acrobat Reader Debugger I get the 'undefined' error. What am I missing?
FYI I have changed the API key...
var API = "https://api.openweathermap.org/data/2.5/weather?q=Berlin&units=metric&lang=de&appid=860b8e982b1aecb176f5aee385c73be0"
var getData = app.trustedFunction(function (cURL) {
app.beginPriv();
var params = {
cVerb: "GET",
cURL: cURL,
oHandler: {
response: function (msg, uri, e) {
var stream = msg;
var string = "";
string = SOAP.stringFromStream(stream);
var data = eval("(" + string + ")");
}
}
};
Net.HTTP.request(params);
app.endPriv();
});
getData(API);
getField('1').value = data.main.temp;

data modified after send with ajax

I am using javascript and the Flask framework
I would like to retrieve in Flask in python the bytes of one or more files that the user will have chosen in my HTML page. To do this, when the user has chosen the files and has clicked on the send button, it triggers a function that uses the FileReader API to retrieve the base64 content of the file(s) that the user has selected.
After that, I would like to send the base64 data to flask with ajax.
But here is my problem, when I get the base64 string in python and compare it with the one in javascript, I notice the number of characters is exactly the same, but some characters are different as you can see on the screenshots below
size of character strings
And when I decode the base64 string, I get different bytes :
bytes variables
This makes me think that the problem is with the use of ajax
Code Python :
#app.route('/test', methods=['POST'])
def test():
if request.method == "POST":
files = eval(request.form.get("files"))
python_data = file.get("data")
javascript_data = "" # Copy from chrome console
len_python_data = len(python_data)
len_javascript_data = len(javascript_data)
base64_bytes_javascript = base64.b64decode(javascript_data)
base64_bytes_python = base64.b64decode(python_data)
Code Javascript :
let array_files = [];
let files_input = document.getElementById("files_input");
let files = files_input.files;
let reader = new FileReader();
function readFile(index) {
if( index >= files.length ) {
let data = "files=" + JSON.stringify(array_files);
$.ajax({
url: '/test',
type: 'POST',
data: data,
success: function (msg) {
console.log(msg)
}
});
return;
}
let file = files[index];
reader.name = file.name;
reader.onload = function() {
let file_info = {};
// get file content
let bin = this.result;
console.log(bin)
let data = bin.split(";")[1].replace("base64,", "");
file_info.name = reader.name;
file_info.data = data;
array_files.push(file_info);
readFile(index + 1)
}
reader.readAsDataURL(file);
}
readFile(0);

The problem is solved
In the base64 character string, the "+" were replaced by spaces after sending it to ajax.

Error: Firebase.set failed: First argument contains undefined in property 'achv_img'

I followed this post
Having form using angular and firebase achievementsapp.firebaseapp.com, you can register and then if you click on the green plus it should pop the form, upload button is not working and when click on Add button it gives me this error Error: Firebase.set failed: First argument contains undefined in property 'achv_img'
controller code:
myApp.controller('MeetingsController',
function($scope, $rootScope, $firebase, Uploader,
CountMeetings, FIREBASE_URL) {
var ref = new Firebase(FIREBASE_URL + '/users/' +
$rootScope.currentUser.$id + '/meetings');
var meetingsInfo = $firebase(ref);
var meetingsObj = meetingsInfo.$asObject();
meetingsObj.$loaded().then(function(data) {
$scope.meetings = data;
}); //make sure meetings data is loaded
$scope.addMeeting = function() {
meetingsInfo.$push({
name: $scope.meetingname,
description: $scope.meetingdescription,
achv_type: $scope.achvtype,
achv_date: $scope.achvdate,
achv_img : $scope.achvimg,
date: Firebase.ServerValue.TIMESTAMP
}).then(function() {
$scope.meetingname='';
$scope.achvtype = '';
$scope.meetingdescription='';
$scope.achvdate='';
$scope.achvimg= $scope.meetingsInfoImgData;
});
Uploader.create($scope.meetingsInfo);
$scope.handleFileSelectAdd = function(evt) {
var f = evt.target.files[0];
var reader = new FileReader();
reader.onload = (function(theFile) {
return function(e) {
var filePayload = e.target.result;
$scope.meetingsInfoImgData = e.target.result;
document.getElementById('pano').src = $scope.meetingsInfoImgData;
};
})(f);
reader.readAsDataURL(f);
};
document.getElementById('file-upload').addEventListener('change', $scope.handleFileSelectAdd, false);
}; //addmeeting
$scope.deleteMeeting = function(key) {
meetingsInfo.$remove(key);
}; //deleteMeeting
}); //MeetingsController

In reader.onload() you take the image data from the file and put it into $scope.meetingsInfoImgData:
reader.onload = (function(theFile) {
return function(e) {
var filePayload = e.target.result;
$scope.meetingsInfoImgData = e.target.result;
document.getElementById('pano').src = $scope.meetingsInfoImgData;
};
})(f);
My original answer then uses its equivalent of this $scope.meetingsInfoImgData later to populate the JavaScript object that it sends to Firebase:
$scope.episode.img1 = $scope.episodeImgData;
var episodes = $firebase(ref).$asArray();
episodes.$add($scope.episode);
Your code does nothing with $scope.meetingsInfoImgData when it tries to create the object in Firebase. You'll probably need something akin to $scope.episode.img1 = $scope.episodeImgData; in your code too.

If for some reason you can not fix it at the source, to make sure your object does not contain any undefined props use this simple trick:
JSON.parse( JSON.stringify(ObjectToSave ) )
For more info take a look at this codePen: http://codepen.io/ajmueller/pen/gLaBLX

How to upload/POST multiple canvas elements

I have to create an image uploader for a future project (No flash, IE10+, FF7+ etc.) that does image resizing/converting/cropping on the clientside and not on the server.
So I made a javascript interface where the user can 'upload' their files and get resized/cropped in the browser directly, without ever contacting the server. The performance is OK, not that good, but it works.
The endresult is an array of canvas elements. The user can edit/crop the images after they got resized, so I keep them as canvas instead of converting them to jpeg. (Which would worsen the initial performance)
Now this works fine, but I don't know what's the best way to actually upload the finished canvas elements to the server now. (Using a asp.net 4 generic handler on the server)
I have tried creating a json object from all elements containing the dataurl of each canvas.
The problem is, when I got 10-40 pictures, the browser starts freezing when creating the dataurls, especially for images that are larger than 2 megabyte.
//images = array of UploadImage
for (var i = 0; i < images.length; i++) {
var data = document.getElementById('cv_' + i).toDataURL('image/jpg');
images[i].data = data.substr(data.indexOf('base64') + 7);
}
Also converting them to a json object (I am using json2.js) usually crashes my browser. (FF7)
My object
var UploadImage = function (pFileName, pName, pDescription) {
this.FileName = pFileName;
this.Name = pName;
this.Description = pDescription;
this.data = null;
}
The upload routine
//images = array of UploadImage
for (var i = 0; i < images.length; i++) {
var data = document.getElementById('cv_' + i).toDataURL('image/jpg');
images[i].data = data.substr(data.indexOf('base64') + 7);
}
var xhr, provider;
xhr = jQuery.ajaxSettings.xhr();
if (xhr.upload) {
xhr.upload.addEventListener('progress', function (e) {
console.log(Math.round((e.loaded * 100) / e.total) + '% done');
}, false);
}
provider = function () {
return xhr;
};
var ddd = JSON.stringify(images); //usually crash here
$.ajax({
type: 'POST',
url: 'upload.ashx',
xhr: provider,
dataType: 'json',
success: function (data) {
alert('ajax success: data = ' + data);
},
error: function () {
alert('ajax error');
},
data: ddd
});
What would be the best way to send the canvas elements to the server?
Should I send them all at once or one by one?

Uploading files one by one is better. Requires less memory and as soon as one file ready to upload, the upload can be started instead of waiting while all files will be prepared.
Use FormData to send files. Allows to upload files in binary format instead of base64 encoded.
var formData = new FormData;
If Firefox use canvas.mozGetAsFile('image.jpg') instead of canvas.toDataUrl(). Allow to avoid unnecessary conversion from base64 to binary.
var file = canvas.mozGetAsFile('image.jpg');
formData.append(file);
In Chrome use BlobBuilder to convert base64 into blob (see dataURItoBlob function
accepted
After playing around with a few things, I managed to figure this out myself.
First of all, this will convert a dataURI to a Blob:
//added for quick reference
function dataURItoBlob(dataURI) {
// convert base64/URLEncoded data component to raw binary data held in a string
var byteString;
if (dataURI.split(',')[0].indexOf('base64') >= 0)
byteString = atob(dataURI.split(',')[1]);
else
byteString = unescape(dataURI.split(',')[1]);
// separate out the mime component
var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];
// write the bytes of the string to a typed array
var ia = new Uint8Array(byteString.length);
for (var i = 0; i < byteString.length; i++) {
ia[i] = byteString.charCodeAt(i);
}
return new Blob([ia], {type:mimeString});
}
From this question):
var blob = dataURItoBlob(canvas.toDataURL('image/jpg'));
formData.append(blob);
And then send the formData object. I'm not sure how to do it in jQuery, but with plain xhr object it like so:
var xhr = new XMLHttpRequest;
xhr.open('POST', 'upload.ashx', false);
xhr.send(formData);
On server you can get files from Files collection:
context.Request.Files[0].SaveAs(...);

Using HTML5 file uploads with AJAX and jQuery

Admittedly, there are similar questions lying around on Stack Overflow, but it seems none quite meet my requirements.
Here is what I'm looking to do:
Upload an entire form of data, one piece of which is a single file
Work with Codeigniter's file upload library
Up until here, all is well. The data gets in my database as I need it. But I'd also like to submit my form via an AJAX post:
Using the native HTML5 File API, not flash or an iframe solution
Preferably interfacing with the low-level .ajax() jQuery method
I think I could imagine how to do this by auto-uploading the file when the field's value changes using pure javascript, but I'd rather do it all in one fell swoop on for submit in jQuery. I'm thinking it's not possible to do via query strings as I need to pass the entire file object, but I'm a little lost on what to do at this point.
Can this be achieved?

It's not too hard. Firstly, take a look at FileReader Interface.
So, when the form is submitted, catch the submission process and
var file = document.getElementById('fileBox').files[0]; //Files[0] = 1st file
var reader = new FileReader();
reader.readAsText(file, 'UTF-8');
reader.onload = shipOff;
//reader.onloadstart = ...
//reader.onprogress = ... <-- Allows you to update a progress bar.
//reader.onabort = ...
//reader.onerror = ...
//reader.onloadend = ...
function shipOff(event) {
var result = event.target.result;
var fileName = document.getElementById('fileBox').files[0].name; //Should be 'picture.jpg'
$.post('/myscript.php', { data: result, name: fileName }, continueSubmission);
}
Then, on the server side (i.e. myscript.php):
$data = $_POST['data'];
$fileName = $_POST['name'];
$serverFile = time().$fileName;
$fp = fopen('/uploads/'.$serverFile,'w'); //Prepends timestamp to prevent overwriting
fwrite($fp, $data);
fclose($fp);
$returnData = array( "serverFile" => $serverFile );
echo json_encode($returnData);
Or something like it. I may be mistaken (and if I am, please, correct me), but this should store the file as something like 1287916771myPicture.jpg in /uploads/ on your server, and respond with a JSON variable (to a continueSubmission() function) containing the fileName on the server.
Check out fwrite() and jQuery.post().
On the above page it details how to use readAsBinaryString(), readAsDataUrl(), and readAsArrayBuffer() for your other needs (e.g. images, videos, etc).

With jQuery (and without FormData API) you can use something like this:
function readFile(file){
var loader = new FileReader();
var def = $.Deferred(), promise = def.promise();
//--- provide classic deferred interface
loader.onload = function (e) { def.resolve(e.target.result); };
loader.onprogress = loader.onloadstart = function (e) { def.notify(e); };
loader.onerror = loader.onabort = function (e) { def.reject(e); };
promise.abort = function () { return loader.abort.apply(loader, arguments); };
loader.readAsBinaryString(file);
return promise;
}
function upload(url, data){
var def = $.Deferred(), promise = def.promise();
var mul = buildMultipart(data);
var req = $.ajax({
url: url,
data: mul.data,
processData: false,
type: "post",
async: true,
contentType: "multipart/form-data; boundary="+mul.bound,
xhr: function() {
var xhr = jQuery.ajaxSettings.xhr();
if (xhr.upload) {
xhr.upload.addEventListener('progress', function(event) {
var percent = 0;
var position = event.loaded || event.position; /*event.position is deprecated*/
var total = event.total;
if (event.lengthComputable) {
percent = Math.ceil(position / total * 100);
def.notify(percent);
}
}, false);
}
return xhr;
}
});
req.done(function(){ def.resolve.apply(def, arguments); })
.fail(function(){ def.reject.apply(def, arguments); });
promise.abort = function(){ return req.abort.apply(req, arguments); }
return promise;
}
var buildMultipart = function(data){
var key, crunks = [], bound = false;
while (!bound) {
bound = $.md5 ? $.md5(new Date().valueOf()) : (new Date().valueOf());
for (key in data) if (~data[key].indexOf(bound)) { bound = false; continue; }
}
for (var key = 0, l = data.length; key < l; key++){
if (typeof(data[key].value) !== "string") {
crunks.push("--"+bound+"\r\n"+
"Content-Disposition: form-data; name=\""+data[key].name+"\"; filename=\""+data[key].value[1]+"\"\r\n"+
"Content-Type: application/octet-stream\r\n"+
"Content-Transfer-Encoding: binary\r\n\r\n"+
data[key].value[0]);
}else{
crunks.push("--"+bound+"\r\n"+
"Content-Disposition: form-data; name=\""+data[key].name+"\"\r\n\r\n"+
data[key].value);
}
}
return {
bound: bound,
data: crunks.join("\r\n")+"\r\n--"+bound+"--"
};
};
//----------
//---------- On submit form:
var form = $("form");
var $file = form.find("#file");
readFile($file[0].files[0]).done(function(fileData){
var formData = form.find(":input:not('#file')").serializeArray();
formData.file = [fileData, $file[0].files[0].name];
upload(form.attr("action"), formData).done(function(){ alert("successfully uploaded!"); });
});
With FormData API you just have to add all fields of your form to FormData object and send it via $.ajax({ url: url, data: formData, processData: false, contentType: false, type:"POST"})