Saving datauri to png file using PHP - creates empty png file - php

I have been trying a dozen ways to save a dataurl generated from an svg to my server. This code seems like it should be working based on other threads I've read here but for some reason it just creates a .png file with 0kb. I went ahead and just copy/pasted the dataurl right into my script to avoid any data being sent to php issues right now, I just want to see the php create the image correctly. Here's my code:
$img="data:image/png;base64,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...j/bZbdmX23g8nv8GSJ7ZsQ3ZHlk6Ep0rW9snCcckDs0DcHSQjueyQrtUSk3vxZJoBMTOLckTx2Yghs3P3CWEc+N3/zspUOm3ASgz3URJWTtzMKXs29tifqCgWQhhcxMVEnFFonqgOcZO8Ds7M0Z047hjsOZMR3vQyzWXyfMTFRt994pBQR2LhrcIvriGdwCehohj4maWScTRECI6ZGNfe3jx/21soaLiNE5i2SEpOsfixVSgvxxGehnn9VbTHBWrMOal3w2bG5MTGxWboZu7dqNeStcNteMre7Fy4Wn7t+CZsKNNoHnMNEI2EEWAoN8WZiEgC4kF2pHxYOITWLMlU+RvvcDoneMDkltqVAVJoVFpTm07gOA2iq+gVkysWf6LhbS5zQwffwpVFP+/NpqC3UqggiE5OQG4cv0xcBCCfeDN7wSFBW4AP8+4uWOly+XA950crPd0NJedRscdMfAdsrC+soAUpOHgGTDtbl8aqmV808tWtu5K9VWzcsjO/KP10455EO2iQBQQ0OJkSTfmNIlh4n2ZzpMy+vb5XskomJjjuS1xQZAQwfzrUXt8BT/BgYaxfgw/KHEJqaRXttZDAVDsA5TBSCmeBQVG5cbyoZ4KmTuJwRE3m1wWHrOiggWFs9vVHo/fPvH/VMcdjw+g64fnlHl4OhyfhexFxPzUxD1Cem9s7xOsiy7VVcbopKDZnCAyOQLVhDfZMUE5Nk9hjPkhICXn6TtuKz8ERuwiUgMcFTuu022pTgbjntjlPHvagEbGwSaAmXNh1M+1BoA1yEhSDx2DPykdh3ccSdKpe9D/9NULn9f1p2y7T/HPb5LkS5YYI3jG7DRJKYMkH619X6dEmtRu2ykKBgdWR6rexDn9l6tyMLHOKctWRJ9scaQ/+6Z5FXjVk+/zjn5yBkul52XNP2G2d+jbDRs3wpZosF886zgIHnf4IP4T2Ll7P/ScKbgqqnMbSbCWLCAgg5nWm1S0LepraXoTmk8t6am4yQykbeAPpwYEp8TNwmtSWo6fo5/B2JQSOCgtfjM/kZeD+iqebYtcvi9bMfeBoRJBD43sSGBOTnF897Vdtv7pon/vvrl3uHPlwL1imjrTbzdq0mqDbhHF77/2+0YTJok+Kow2gRAg7L5gQw/v8PaqCA15/YCYqB15+MnqVBi9DGNBN6SNcPoAzH6FZh+oQ5NWwZare9UsPPQ8kM0OLkg8DRlQffv2J1NrbTekENlrvfPhNsqMAMpFZHArRWBTQKA2rUIAPItBIveGHsU+CZL7vfvgBLD4VyYnTEZCjllkHsVtD2YuAiskbY+hNcQ4qD2AtDzmmgAgl0ERwQ/AEO+7KAenCjYGiEAKxhQqtdHUMjFAa/K0EjGaDRhktfP/7/BV33AYqzBGklvMcnwE6rBY3MYBtNocXFjaDGFOh6Cvj0D45FvaMNk8Gf7kZdOBoCoyEwGgKjITAaAqMhMIhCAAC+P4HZvnVG3QAAAABJRU5ErkJggg==";
$filedata = substr($img, strpos($img,",")+1);
file_put_contents("testfile2.png", base64_decode($filedata));
echo "file created";
Here's the jquery code that's generating the data. I just copy it from the alert to test in this script:
$("#testclick").click(function() {
var svg = document.getElementById("map").innerHTML; // or whatever you call it
//alert(svg);
$('#load-target').html(svg);
var canvas = $('#load-target svg')[0];
try {
svgAsDataUri(canvas, null, function(uri) {
var image = new Image();
image.src = uri;
image.onload = function() {
var canvas = document.createElement('canvas');
canvas.width = image.width;
canvas.height = image.height;
var context = canvas.getContext('2d');
context.drawImage(image, 0, 0);
var a = document.createElement('a');
a.download = name;
alert(canvas.toDataURL('image/png'));
a.href = canvas.toDataURL('image/png');
document.body.appendChild(a);
a.click();
}
//alert(uri);
$.post("http://www.srqnews.com/maps/create.php",
{
type:"PNG",
datauri:uri
},
function(data,status){
alert("Data: " + data + "\nStatus: " + status);
});
});
} catch(err) {
alert(err.message);
}
});

Related

send jQuery object (exif coordinates) to my table in MySql through php

How can I send my converted exif coordinates (in decimals) to my db using php and mysql? I'm using one file for this (addnew.php)
I'm sending information through a form in php like:
if(isset($_POST['btn_submit'])){
$username = $_POST['userName'];
$watervisibility = $_POST ['waterVisibility'];
$divinglocation = $_POST['divingLocation'];
$imgFile = $_FILES['user_art']['name'];
$tmp_dir = $_FILES['user_art']['tmp_name'];
$imgSize = $_FILES['user_art']['size'];
I also use libraries to convert exif to decimals ( on change ) to avoid clicking submit. This is all still in the same php file (addnew.php) (this is where i'm having a problem)
var lat;
var latref;
var long;
var longref;
var dec;
var myLatLng;
document.getElementById("input-group").onchange = function(e) {
EXIF.getData(e.target.files[0], function() {
//console.log(EXIF.pretty(this));
long = EXIF.getTag(this, 'GPSLongitude');
longref = EXIF.getTag(this, 'GPSLongitudeRef');
lat = EXIF.getTag(this, 'GPSLatitude');
latref = EXIF.getTag(this, 'GPSLatitudeRef');
dec = dms2dec(long, longref, lat, latref);
console.log("Decimal 1: " + dec[0] + " Decimal 2: " + dec[1]);
console.log("Longref: " + longref);
console.log("Latref: " + latref);
console.log("Long Length: " + long.length);
console.log("Longtitude: " + long);
console.log("Latitude: " + lat);
myLatLng = {lat: dec[1], lng: dec[0]}
myLat = {lat: dec[1]}
myLng = {lng: dec[0]}
console.log(myLat);
console.log(myLng);
});
}
Now I got the decimals and basically just want to send
myLat = {lat: dec[1]}
myLng = {lng: dec[0]}
to my db through php at the same time i'm submitting everything else.
I've tried Send JSON data from Javascript to PHP but I can't seem to get the hang of it
Any ideas?
Thanks!
To send javascript obj to php using json and ajax:
js:
var dataPost = {
"var": "foo"
};
var dataString = JSON.stringify(dataPost);
$.ajax({
url: 'server.php',
data: {myData: dataString},
type: 'POST',
success: function(response) {
alert(response);
}
});
to use that object in php:
$obj = json_decode($_POST["myData"]);
echo $obj->var;

function doc.save width jspdf

In fact we generate from an HTML file administrative documents for each customer.
On the other hand this pdf generated will be saved to a specific folder on the server to be sent to the customer concerned.
Can I serve the backup path by doc.save order?
My code:
function createpdf() {
var canvasToImage = function(canvas){
var img = new Image();
var dataURL = canvas.toDataURL('image/png');
img.src = dataURL;
return img;
};
var a4 =[595.28,2000];
var canvasShiftImage = function(oldCanvas,shiftAmt){
shiftAmt = parseInt(shiftAmt) || 0;
if(!shiftAmt){ return oldCanvas; }
var newCanvas = document.createElement('canvas');
newCanvas.height = oldCanvas.height - shiftAmt;
newCanvas.width = oldCanvas.width;
var ctx = newCanvas.getContext('2d');
var img = canvasToImage(oldCanvas);
ctx.drawImage(img,0, shiftAmt, img.width, img.height, 0, 0, img.width, img.height);
return newCanvas;
};
var canvasToImageSuccess = function(canvas){
var pdf = new jsPDF('p','px','letter'),
pdfInternals = pdf.internal,
pdfPageSize = pdfInternals.pageSize,
pdfScaleFactor = pdfInternals.scaleFactor,
pdfPageWidth = pdfPageSize.width,
pdfPageHeight = pdfPageSize.height,
totalPdfHeight = 0,
htmlPageHeight = canvas.height,
htmlScaleFactor = canvas.width / (pdfPageWidth * pdfScaleFactor),
safetyNet = 0;
while(totalPdfHeight < htmlPageHeight && safetyNet < 15){
var newCanvas = canvasShiftImage(canvas, totalPdfHeight);
pdf.addImage(newCanvas, 'png',0, 0, pdfPageWidth, 0, null, 'NONE');
totalPdfHeight += (pdfPageHeight * pdfScaleFactor * htmlScaleFactor );
if(totalPdfHeight < htmlPageHeight){
pdf.addPage();
}
safetyNet++;
}
pdf.save('<?php echo $mavariable?>.pdf');
};
html2canvas($('main')[0], {
onrendered: function(canvas){
canvasToImageSuccess(canvas);
}
});
}
I guess you want to send the PDF in the mail attachment. For from client side code make a request to server with the generated PDF's (by jsPDF) base64 string format.
var pdfData = pdf.output();
You can post PDF data (base64) to server there again you have convert base64 string to PDF then save it to any temporary path if you want. Thereby you can mail it the PDF.
https://stackoverflow.com/a/35684594/2090459

How to pass base64 encoded image to php?

I was wondering how I would get php script to retrieve my base64 encoded image then write to server? I tried doing a post dump from my php script and I keep getting a response that it is empty. I've tried following a few other stackoverflow guides on this but none of them use a factory afaik.
js
var app = angular.module("app", ["ui.bootstrap"]);
//http://stackoverflow.com/questions/18571001/file-upload-using-angularjs
app.factory('API', function ($http) {
return {
uploadImage: function (image) {
return $http.post('/js/upload.php', image);
}
}
});
app.controller('MainController',['$scope', '$http', 'API', function($scope, $http, API) {
$scope.imageUrl = "";
$scope.template = "";
$scope.templates = [
'select an option...',
'MakeGray',
'Canny'
];
$scope.template = $scope.templates[0];
$scope.add = function() {
var f = document.getElementById('fileToUpload').files[0]; // name of image
var files = document.getElementById('fileToUpload').files;
var r = new FileReader();
r.onload = function(event){
console.log(event.target.result);
}
r.onloadend = function(e) {
var data = e.target.result;
var formData = new FormData();
$("#img1").prop("src", data);
$("#img2").prop("src", data);
formData.append("fileToUpload", f,f.name);
API.uploadImage(formData)
.success(function (imgUrl) {
$scope.imageUrl = imgUrl;
})
.error (function (error) {
});
}
r.readAsDataURL(f);
}
}]);
php
<?php
if(isset($_FILES['fileToUpload'])){
$errors= array();
$file_name = $_FILES['fileToUpload']['name'];
$file_size =$_FILES['fileToUpload']['size'];
$file_tmp =$_FILES['fileToUpload']['tmp_name'];
$file_type=$_FILES['fileToUpload']['type'];
$file_ext = strtolower(pathinfo($file_name, PATHINFO_EXTENSION));
$extensions = array("jpeg","jpg","png");
if(in_array($file_ext,$extensions )=== false){
$errors[]="image extension not allowed, please choose a JPEG or PNG file.";
}
if($file_size > 2097152){
$errors[]='File size cannot exceed 2 MB';
}
if(empty($errors)==true){
move_uploaded_file($file_tmp,"../uploads/".$file_name);
echo " uploaded file: " . "images/" . $file_name;
}else{
print_r($errors);
}
}
else{
$errors= array();
$errors[]="No image found";
print_r($errors);
}
?>
Angular have a particularity in concern the uploading.
First, you have to kno, angular's default transformRequest function will try to serialize our FormData object, so we override it with the identity function to leave the data intact.
Next, the default content-type header for POST requests is "application/json", so you must to change this because you want to upload a file.
By setting 'Content-Type': undefined, the browser sets the Content-Type to multipart/form-data himself and fills in the correct boundary.
Manually setting 'Content-Type': multipart/form-data will fail to fill in the boundary parameter of the request.
Look about others possible issues : https://docs.angularjs.org/api/ng/service/$http
Now you can get you image from $_POST global array of PHP.
Fixed code
uploadImage: function (formData)
{
return $http.post('js/upload.php', formData,
{
transformRequest: angular.identity,
headers: {'Content-Type': undefined}
});
}
Note:
That the below service uses the FormData object which is not supported by IE9 and earlier.

Yii: Unable to upload file using Ajax

After reading the accepted answer on this post, I am trying to implement the same but not able to figure out the problem. When I select a file, nothing is available in $_FILES on the server side. What am I doing wrong? I am using Apache 2.2.22, Yii 1.12
My view file
<form enctype="multipart/form-data" action='/webapp/index.php/emu/default/uploadFile' method="POST">
<input type="hidden" name="MAX_FILE_SIZE" value="30000" />
<input id="files" type="file" >
</form>
<script>
document.getElementById('files').addEventListener('change', function(e) {
var file = this.files[0];
var xhr = new XMLHttpRequest();
xhr.file = file; // not necessary if you create scopes like this
xhr.addEventListener('progress', function(e) {
var done = e.position || e.loaded, total = e.totalSize || e.total;
console.log('xhr progress: ' + (Math.floor(done/total*1000)/10) + '%');
}, false);
if ( xhr.upload ) {
xhr.upload.onprogress = function(e) {
var done = e.position || e.loaded, total = e.totalSize || e.total;
console.log('xhr.upload progress: ' + done + ' / ' + total + ' = ' + (Math.floor(done/total*1000)/10) + '%');
};
}
xhr.onreadystatechange = function(e) {
if ( 4 == this.readyState ) {
console.log(['xhr upload complete', e]);
}
};
var url='/webapp/index.php/emu/default/uploadFile';
xhr.open('post', url, true);
xhr.send(file);
}, false);
</script>
Controller action:
public function actionUploadFile(){
Yii::log(CJSON::encode($_FILES['files']));
}
Yii::log outputs following:
2014/12/16 19:59:29 [error] [php] Undefined index: files
To upload a file transparently via ajax you'll have to use a FormData object
var file = this.files[0];
var xhr = new XMLHttpRequest();
var data = new FormData();
data.append('files', file);
...
xhr.send(data);

Trying to save canvas data to server [duplicate]

I'm working on a generative art project where I would like to allow users to save the resulting images from an algorithm. The general idea is:
Create an image on an HTML5 Canvas using a generative algorithm
When the image is completed, allow users to save the canvas as an image file to the server
Allow the user to either download the image or add it to a gallery of pieces of produced using the algorithm.
However, I’m stuck on the second step. After some help from Google, I found this blog post, which seemed to be exactly what I wanted:
Which led to the JavaScript code:
function saveImage() {
var canvasData = canvas.toDataURL("image/png");
var ajax = new XMLHttpRequest();
ajax.open("POST", "testSave.php", false);
ajax.onreadystatechange = function() {
console.log(ajax.responseText);
}
ajax.setRequestHeader("Content-Type", "application/upload");
ajax.send("imgData=" + canvasData);
}
and corresponding PHP (testSave.php):
<?php
if (isset($GLOBALS["HTTP_RAW_POST_DATA"])) {
$imageData = $GLOBALS['HTTP_RAW_POST_DATA'];
$filteredData = substr($imageData, strpos($imageData, ",") + 1);
$unencodedData = base64_decode($filteredData);
$fp = fopen('/path/to/file.png', 'wb');
fwrite($fp, $unencodedData);
fclose($fp);
}
?>
But this doesn’t seem to do anything at all.
More Googling turns up this blog post which is based off of the previous tutorial. Not very different, but perhaps worth a try:
$data = $_POST['imgData'];
$file = "/path/to/file.png";
$uri = substr($data,strpos($data, ",") + 1);
file_put_contents($file, base64_decode($uri));
echo $file;
This one creates a file (yay) but it’s corrupted and doesn’t seem to contain anything. It also appears to be empty (file size of 0).
Is there anything really obvious that I’m doing wrong? The path where I’m storing my file is writable, so that isn’t an issue, but nothing seems to be happening and I’m not really sure how to debug this.
Edit
Following Salvidor Dali’s link I changed the AJAX request to be:
function saveImage() {
var canvasData = canvas.toDataURL("image/png");
var xmlHttpReq = false;
if (window.XMLHttpRequest) {
ajax = new XMLHttpRequest();
}
else if (window.ActiveXObject) {
ajax = new ActiveXObject("Microsoft.XMLHTTP");
}
ajax.open("POST", "testSave.php", false);
ajax.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
ajax.onreadystatechange = function() {
console.log(ajax.responseText);
}
ajax.send("imgData=" + canvasData);
}
And now the image file is created and isn’t empty! It seems as if the content type matters and that changing it to x-www-form-urlencoded allowed the image data to be sent.
The console returns the (rather large) string of base64 code and the datafile is ~140 kB. However, I still can’t open it and it seems to not be formatted as an image.
Here is an example of how to achieve what you need:
Draw something (taken from canvas tutorial)
<canvas id="myCanvas" width="578" height="200"></canvas>
<script>
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
// begin custom shape
context.beginPath();
context.moveTo(170, 80);
context.bezierCurveTo(130, 100, 130, 150, 230, 150);
context.bezierCurveTo(250, 180, 320, 180, 340, 150);
context.bezierCurveTo(420, 150, 420, 120, 390, 100);
context.bezierCurveTo(430, 40, 370, 30, 340, 50);
context.bezierCurveTo(320, 5, 250, 20, 250, 50);
context.bezierCurveTo(200, 5, 150, 20, 170, 80);
// complete custom shape
context.closePath();
context.lineWidth = 5;
context.fillStyle = '#8ED6FF';
context.fill();
context.strokeStyle = 'blue';
context.stroke();
</script>
Convert canvas image to URL format (base64)
// script
var dataURL = canvas.toDataURL();
Send it to your server via Ajax
$.ajax({
type: "POST",
url: "script.php",
data: {
imgBase64: dataURL
}
}).done(function(o) {
console.log('saved');
// If you want the file to be visible in the browser
// - please modify the callback in javascript. All you
// need is to return the url to the file, you just saved
// and than put the image in your browser.
});
Save base64 on your server as an image (here is how to do this in PHP, the same ideas is in every language. Server side in PHP can be found here):
I played with this two weeks ago, it's very simple. The only problem is that all the tutorials just talk about saving the image locally. This is how I did it:
1) I set up a form so I can use a POST method.
2) When the user is done drawing, he can click the "Save" button.
3) When the button is clicked I take the image data and put it into a hidden field. After that I submit the form.
document.getElementById('my_hidden').value = canvas.toDataURL('image/png');
document.forms["form1"].submit();
4) When the form is submited I have this small php script:
<?php
$upload_dir = somehow_get_upload_dir(); //implement this function yourself
$img = $_POST['my_hidden'];
$img = str_replace('data:image/png;base64,', '', $img);
$img = str_replace(' ', '+', $img);
$data = base64_decode($img);
$file = $upload_dir."image_name.png";
$success = file_put_contents($file, $data);
header('Location: '.$_POST['return_url']);
?>
I think you should convert the image to base64 and then to Blob and send it to the server. When you use base64 images, a lot of lines will be sent to server. With blob, it's only the file.
You can use this code bellow:
function dataURLtoBlob(dataURL) {
let array, binary, i, len;
binary = atob(dataURL.split(',')[1]);
array = [];
i = 0;
len = binary.length;
while (i < len) {
array.push(binary.charCodeAt(i));
i++;
}
return new Blob([new Uint8Array(array)], {
type: 'image/png'
});
};
And canvas code here:
const canvas = document.getElementById('canvas');
const file = dataURLtoBlob( canvas.toDataURL() );
After that you can use ajax with Form:
const fd = new FormData;
fd.append('image', file);
$.ajax({
type: 'POST',
url: '/url-to-save',
data: fd,
processData: false,
contentType: false
});
The code in CoffeeScript syntax:
dataURLtoBlob = (dataURL) ->
# Decode the dataURL
binary = atob(dataURL.split(',')[1])
# Create 8-bit unsigned array
array = []
i = 0
while i < binary.length
array.push binary.charCodeAt(i)
i++
# Return our Blob object
new Blob([ new Uint8Array(array) ], type: 'image/png')
And canvas code here:
canvas = document.getElementById('canvas')
file = dataURLtoBlob(canvas.toDataURL())
After that you can use ajax with Form:
fd = new FormData
# Append our Canvas image file to the form data
fd.append 'image', file
$.ajax
type: 'POST'
url: '/url-to-save'
data: fd
processData: false
contentType: false
Send canvas image to PHP:
var photo = canvas.toDataURL('image/jpeg');
$.ajax({
method: 'POST',
url: 'photo_upload.php',
data: {
photo: photo
}
});
Here's PHP script:
photo_upload.php
<?php
$data = $_POST['photo'];
list($type, $data) = explode(';', $data);
list(, $data) = explode(',', $data);
$data = base64_decode($data);
mkdir($_SERVER['DOCUMENT_ROOT'] . "/photos");
file_put_contents($_SERVER['DOCUMENT_ROOT'] . "/photos/".time().'.png', $data);
die;
?>
I've worked on something similar.
Had to convert canvas Base64-encoded image to Uint8Array Blob.
function b64ToUint8Array(b64Image) {
var img = atob(b64Image.split(',')[1]);
var img_buffer = [];
var i = 0;
while (i < img.length) {
img_buffer.push(img.charCodeAt(i));
i++;
}
return new Uint8Array(img_buffer);
}
var b64Image = canvas.toDataURL('image/jpeg');
var u8Image = b64ToUint8Array(b64Image);
var formData = new FormData();
formData.append("image", new Blob([ u8Image ], {type: "image/jpg"}));
var xhr = new XMLHttpRequest();
xhr.open("POST", "/api/upload", true);
xhr.send(formData);
If you want to save data that is derived from a Javascript canvas.toDataURL() function, you have to convert blanks into plusses. If you do not do that, the decoded data is corrupted:
<?php
$encodedData = str_replace(' ','+',$encodedData);
$decocedData = base64_decode($encodedData);
?>
http://php.net/manual/ro/function.base64-decode.php
In addition to Salvador Dali's answer:
on the server side don't forget that the data comes in base64 string format. It's important because in some programming languages you need to explisitely say that this string should be regarded as bytes not simple Unicode string.
Otherwise decoding won't work: the image will be saved but it will be an unreadable file.
I just made an imageCrop and Upload feature with
https://www.npmjs.com/package/react-image-crop
to get the ImagePreview ( the cropped image rendering in a canvas)
https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/toBlob
canvas.toBlob(function(blob){...}, 'image/jpeg', 0.95);
I prefer sending data in blob with content type image/jpeg rather than toDataURL ( a huge base64 string`
My implementation for uploading to Azure Blob using SAS URL
axios.post(azure_sas_url, image_in_blob, {
headers: {
'x-ms-blob-type': 'BlockBlob',
'Content-Type': 'image/jpeg'
}
})

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