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How to get not loaded resources?

I'm trying to get all not loaded elements in a webpage by including a script in the head of the index.html but I've some problems.
This is the code:
document.addEventListener('DOMContentLoaded', function () {
console.log("here");
var scripts = document.getElementsByTagName('script');
for(var i=0;i<scripts.length;i++){
scripts[i].onerror =function(message, source, lineno) {
console.log("JS: Error SCRIPT");
}
}
var imgs = document.getElementsByTagName('img');
for(var i=0;i<imgs.length;i++){
imgs[i].onerror =function(message, source, lineno) {
console.log("JS: Error IMG ");
}
}
var links = document.getElementsByTagName('link');
for(var i=0;i<links.length;i++){
links[i].onerror = function(message, source, lineno){
console.log("JS: Error CSS ");
}
}
});
I put 3 wrong CSS, Images and Scripts (they don't exist as resources) inside the HTML file where I call the script.
When I run locally the index.html I get "Error IMG" and "Error CSS".
When I run on the server I get only "Error IMG".
In both cases, I don't get "Error SCRIPT".
What I'm doing wrong?
UPDATE: This is the code
appmetrics.js
//class that store page resource data
/*
ES6
class Resource{
constructor(name,type,start,end,duration){
this.name = name;
this.type = type;
this.start = start;
this.end = end;
this.duration = duration;
}
}
*/
function Resource (name,type,start,end,duration){
this.name = name;
this.type = type;
this.start = start;
this.end = end;
this.duration = duration;
}
/*
ES6
class Errors{
constructor(name,source,line){
this.name = name;
this.source = source;
this.line = line;
}
}
*/
function Errors(name,source,line){
this.name = name;
this.source = source;
this.line = line;
}
//endpoint to send data
var endpoint = "https://requestb.in/sr8wnnsr"
var resources = Array();
var errors = Array();
var pageLoadTime;
var start = performance.now();
window.onload = function(){
pageLoadTime = performance.now()-start;
console.log("Page loading time: " + pageLoadTime);
//getting page resources and pushing them into the array
var res = performance.getEntriesByType("resource");
res.forEach(function add(item){
resources.push(new Resource(item.name,item.initiatorType,item.startTime,item.responseEnd,item.duration));
})
console.log(resources);
var jsonRes = JSON.stringify(resources);
//sendMetricToEndpoint(jsonRes);
//sendMetricToEndpoint(pageLoadTime.toString());
}
window.onerror = function(message, source, lineno) {
console.log("Error detected!" + "\nMessage: " +message +"\nSource: "+ source +"\nLine: "+ lineno);
errors.push(new Errors(message,source,lineno));
console.log(errors);
}
//Not working code
/*
document.addEventListener('DOMContentLoaded', function () {
console.log("here");
var scripts = document.getElementsByTagName('script');
for(var i=0;i<scripts.length;i++){
scripts[i].onerror =function(message, source, lineno) {
console.log("JS: Errore SCRIPT");
}
}
var imgs = document.getElementsByTagName('img');
for(var i=0;i<imgs.length;i++){
imgs[i].onerror =function(message, source, lineno) {
console.log("JS: Errore IMG ");
}
}
var links = document.getElementsByTagName('link');
for(var i=0;i<links.length;i++){
links[i].onerror = function(message, source, lineno){
console.log("JS: Errore CSS ");
}
}
});
*/
//StackOverflow solution start
var scripts = [];
for (var i = 0, nodes = document.getElementsByTagName('script'); i < nodes.length; i++) {
scripts[i] = { source: nodes[i].src, loaded: false };
nodes[i].onload = function() {
var loadedNode = this;
var index = scripts.findIndex(function(script) {
return script.source === loadedNode.src;
});
scripts[index].loaded = true;
};
}
var links = [];
for (var i = 0, nodes = document.getElementsByTagName('link'); i < nodes.length; i++) {
links[i] = { source: nodes[i].href, loaded: false };
nodes[i].onload = function() {
var loadedNode = this;
var index = links.findIndex(function(link) {
link.href === loadedNode.href;
});
links[index].loaded = true;
};
}
document.addEventListener('DOMContentLoaded', function() {
console.log("here");
scripts.filter(function(script) {
return !script.loaded;
}).forEach(function(script) {
console.log("Error loading script: " + script.source);
});
links.filter(function(link) {
return !link.loaded;
}).forEach(function(link) {
console.log("Error loading link: " + link.source);
});
// and the rest of the elements
var imgs = document.getElementsByTagName('img');
for (var i = 0; i < imgs.length; i++) {
imgs[i].onerror = function() {
console.log("Error loading image: " + this.src);
};
}
});
//StackOverflow solution stop
/**
* Function that send metric to endpoint.
*
* #param {string} endpoint Where to send data.
* #param {*} data data to send (JSON or string)
*/
function sendMetricToEndpoint(data){
console.log("Sending metrics to endpoint");
var xhttp;
xhttp=new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (xhttp.readyState == 4 && xhttp.status == 200) {
console.log(xhttp.responseText);
}
};
xhttp.open("POST", endpoint, true);
//xhttp.setRequestHeader("Content-type", "application/json");
xhttp.send(data);
}
index.html
<html>
<head>
<!--<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>-->
<script src="js/appmetricsmod.js"></script>
<link rel="stylesheet" href="styletests.css">
<link rel="stylesheet" href="styletestss.css">
<link rel="stylesheet" href="styletestsss.css">
<script src="js/error1.js"></script>
<script src="js/error2.js"></script>
<script src="js/error3.js"></script>
</head>
<body>
<img src="imgtest.png"></img>
<img src="imgErr1.png"></img>
<img src="imgErr2.png"></img>
<img src="imgErr3.png"></img>
<img src="http://images.centrometeoitaliano.it/wp-content/uploads/2016/11/15/l1.jpg"></img>
<div class="divtest">
hello this is a test
</div>
<script>
</script>
</body>
</html>

Sadly, you you cannot get link nor script error load with onerror event, but you can handle the loaded content, and filter which were not loaded. This is possible with the load event for the link and script tags.
var scripts = [];
for (var i = 0, nodes = document.getElementsByTagName('script'); i < nodes.length; i++) {
scripts[i] = { source: nodes[i].src, loaded: false };
nodes[i].onload = function() {
var loadedNode = this;
var index = scripts.findIndex(function(script) {
return script.source === loadedNode.src;
});
scripts[index].loaded = true;
};
}
var links = [];
for (var i = 0, nodes = document.getElementsByTagName('link'); i < nodes.length; i++) {
links[i] = { source: nodes[i].href, loaded: false };
nodes[i].onload = function() {
var loadedNode = this;
var index = links.findIndex(function(link) {
link.href === loadedNode.href;
});
links[index].loaded = true;
};
}
document.addEventListener('DOMContentLoaded', function() {
console.log("here");
scripts.filter(function(script) {
return !script.loaded;
}).forEach(function(script) {
console.log("Error loading script: " + script.source);
});
links.filter(function(link) {
return !link.loaded;
}).forEach(function(link) {
console.log("Error loading link: " + link.source);
});
// and the rest of the elements
var imgs = document.getElementsByTagName('img');
for (var i = 0; i < imgs.length; i++) {
imgs[i].onerror = function() {
console.log("Error loading image: " + this.src);
};
}
});
Hope it helps :)

Using the classes Resources and Errors above, I solved the problem by taking all the resources of the page and then removing the working ones. The result is an array of not loaded resources.
This is the code:
var res = performance.getEntriesByType("resource");
res.forEach(function add(item){
resources.push(new Resource(item.name,
item.initiatorType,
item.startTime,
item.responseEnd,
item.duration));
})
var flag = true;
var imgs = document.getElementsByTagName('img');
for(var i=0;i<imgs.length;i++){
for(var j=0;j<resources.length;j++){
if(imgs[i].src == resources[j].name){
flag = false;
}
}
if(flag && imgs[i].src){
errors.push(new Errors("RES NOT FOUND",imgs[i].src,null));
}
flag = true;
}
var scripts = document.getElementsByTagName('script');
for(var i=0;i<scripts.length;i++){
for(var j=0;j<resources.length;j++){
if(scripts[i].src == resources[j].name){
flag = false;
}
}
if(flag && scripts[i].src){
errors.push(new Errors("RES NOT FOUND",scripts[i].src,null));
}
flag = true;
}
var links = document.getElementsByTagName('link');
for(var i=0;i<links.length;i++){
for(var j=0;j<resources.length;j++){
if(links[i].src == resources[j].name){
flag = false;
}
}
if(flag && links[i].href){
errors.push(new Errors("RES NOT FOUND",links[i].href,null));
}
flag = true;
}
console.log(resources);
console.log(errors);

JS search returned xhr.responseText for div then remove div

I would like to search a xhr.responseText for a div with an id like "something" and then remove all the content from the xhr.responseText contained within that div.
Here is my xhr code:
function getSource(source) {
var url = source[0];
var date = source[1];
/****DEALS WITH CORS****/
var cors_api_host = 'cors-anywhere.herokuapp.com';
var cors_api_url = 'https://' + cors_api_host + '/';
var slice = [].slice;
var origin = self.location.protocol + '//' + self.location.host;
var open = XMLHttpRequest.prototype.open;
XMLHttpRequest.prototype.open = function () {
var args = slice.call(arguments);
var targetOrigin = /^https?:\/\/([^\/]+)/i.exec(args[1]);
if (targetOrigin && targetOrigin[0].toLowerCase() !== origin &&
targetOrigin[1] !== cors_api_host) {
args[1] = cors_api_url + args[1];
}
return open.apply(this, args);
};
/****END DEALS WITH CORS****/
var xhr = new XMLHttpRequest();
xhr.open("GET", cors_api_url+url, true);
xhr.onreadystatechange = function() {
if (xhr.readyState == 4) {
var resp = xhr.responseText;
var respWithoutDiv = removeErroneousData(resp);
}
else{
return "Failed to remove data.";
}
}
xhr.send();
}
remove div here:
/*This must be in JS not JQUERY, its in a web worker*/
function removeErroneousData(resp) {
var removedDivResp = "";
/*pseudo code for removing div*/
if (resp.contains(div with id disclosures){
removedDivResp = resp.removeData(div, 'disclosures');
}
return removedDivResp;
}

You can dump the response in a div and then search for that div you want empty its content.
xhr.onreadystatechange = function() {
if (xhr.readyState == 4) {
var resp = xhr.responseText;
$('div').attr('id', 'resp').html(resp);
$('#resp').find('disclosures').html('');
//var respWithoutDiv = removeErroneousData(resp);
}
else{
return "Failed to remove data.";
}
}

Multiple XMLHttpRequest.send or eventlisteners memory leak?

I'm currently implementing an upload for files. Because I've to handle huge files here and there I've started to slice files and send them in 1mb chunks which works great as long as file are <~500MB after that it seems that memory isn't freed anyone randomly and I can't figure out what I'm missing here.
Prepare chunks
var sliceCount = 0;
var sendCount = 0;
var fileID = generateUUID();
var maxChunks = 0;
var userNotified = false;
function parseFile(file)
{
var fileSize = file.size;
var chunkSize = 1024 * 1024;//64 * 1024; // bytes
var offset = 0;
var self = this; // we need a reference to the current object
var chunkReaderBlock = null;
var numberOfChunks = fileSize / chunkSize;
maxChunks = Math.ceil(numberOfChunks);
// gets called if chunk is read into memory
var readEventHandler = function (evt)
{
if (evt.target.error == null) {
offset += evt.target.result.byteLength;
sendChunkAsBinary(evt.target.result);
}
else
{
console.log("Read error: " + evt.target.error);
return;
}
if (offset >= fileSize) {
console.log("Done reading file");
return;
}
// of to the next chunk
chunkReaderBlock(offset, chunkSize, file);
}
chunkReaderBlock = function (_offset, length, _file)
{
var r = new FileReader();
var blob = _file.slice(_offset, length + _offset);
sliceCount++;
console.log("Slicecount: " + sliceCount);
r.onload = readEventHandler;
r.readAsArrayBuffer(blob);
blob = null;
r = null;
}
// now let's start the read with the first block
chunkReaderBlock(offset, chunkSize, file);
}
Send Chunks
function sendChunkAsBinary(chunk)
{
var progressbar = $("#progressbar"), bar = progressbar.find('.uk-progress-bar');
// create XHR instance
var xhr = new XMLHttpRequest();
// send the file through POST
xhr.open("POST", 'upload.php', true);
var progressHandler = function (e)
{
// get percentage of how much of the current file has been sent
var position = e.loaded || e.position;
var total = e.total || e.totalSize;
var percentage = Math.round((sendCount / maxChunks) * 100);
// set bar width to keep track of progress
bar.css("width", percentage + "%").text(percentage + "%");
}
// let's track upload progress
var eventSource = xhr.upload || xhr;
eventSource.addEventListener("progress", progressHandler);
// state change observer - we need to know when and if the file was successfully uploaded
xhr.onreadystatechange = function ()
{
if (xhr.readyState == 4)
{
if (xhr.status == 200)
{
eventSource.removeEventListener("progress", progressHandler);
if (sendCount == maxChunks && !userNotified)
{
userNotified = true;
notifyUserSuccess("Datei hochgeladen!");
setTimeout(function ()
{
progressbar.addClass("uk-invisible");
bar.css("width", "0%").text("0%");
}, 250);
updateDocList();
}
}
else
{
notifyUser("Fehler beim hochladen der Datei!");
}
}
};
var blob;
if (typeof window.Blob == "function") {
blob = new Blob([chunk]);
} else {
var bb = new (window.MozBlobBuilder || window.WebKitBlobBuilder || window.BlobBuilder)();
bb.append(chunk);
blob = bb.getBlob();
}
sendCount++;
var formData = new FormData();
formData.append("chunkNumber", sendCount);
formData.append("maxChunks", maxChunks);
formData.append("fileID", fileID);
formData.append("chunkpart", blob);
xhr.send(formData);
progressbar.removeClass("uk-invisible");
console.log("Sendcount: " + sendCount);
}
If I attach to the debugger within Visual Studio 2015 it take a bit but soon I get an OutOfMemoryException in the send function at exactly this line: blob = new Blob([chunk]);. It's all the time the same line where the exception occures.
As soon as the Exception happens I get POST [...]/upload.php net::ERR_FILE_NOT_FOUND however I still got the chunks in my php-file.
Here's a Timeline-graph of my error
What I dont understand, I'm not able to see increasing memory inside the Task-Manager (a few mb of course but not close to 16gb ram I got).
So can anyone tell me where this leak comes from? What am I missing?

Calling data from JSON file using AJAX

I am trying to load some data from my JSON file using AJAX. The file is called external-file.json. Here is the code, it includes other parts that haven't got to do with the data loading.The part I'm not sure of begins in the getViaAjax funtion. I can't seem to find my error.
function flip(){
if(vlib_front.style.transform){
el.children[1].style.transform = "";
el.children[0].style.transform = "";
} else {
el.children[1].style.transform = "perspective(600px) rotateY(-180deg)";
el.children[0].style.transform = "perspective(600px) rotateY(0deg)";
}
}
var vlib_front = document.getElementById('front');
var el = document.getElementById('flip3D');
el.addEventListener('click', flip);
var word = null; var explanation = null;
var i=0;
function updateDiv(id, content) {
document.getElementById(id).innerHTML = content;
document.getElementById(id).innerHTML = content;
}
updateDiv('the-h',word[i]);
updateDiv('the-p',explanation[i])
function counter (index, step){
if (word[index+step] !== undefined) {
index+=step;
i=index;
updateDiv('the-h',word[index]);
updateDiv('the-p',explanation[index]);
}
}
var decos = document.getElementById('deco');
decos.addEventListener('click', function() {
counter(i,-1);
}, false);
var incos = document.getElementById('inco');
incos.addEventListener('click', function() {
counter(i,+1);
}, false);
function getViaAjax("external-file.json", callback) { // url being the url to external File holding the json
var r = new XMLHttpRequest();
r.open("GET", "external-file.json", true);
r.onload = function() {
if(this.status < 400 && this.status > 199) {
if(typeof callback === "function")
callback(JSON.parse(this.response));
} else {
console.log("err");// server reached but gave shitty status code}
};
}
r.onerror = function(err) {console.log("error Ajax.get "+url);console.log(err);}
r.send();
}
function yourLoadingFunction(jsonData) {
word = jsonData.words;
explanation = jsonData.explanation;
updateDiv('the-h',word[i]);
updateDiv('the-p',explanation[i])
// then call whatever it is to trigger the update within the page
}
getViaAjax("external-file.json", yourLoadingFunction)

As #light said, this:
function getViaAjax("external-file.json", callback) { // url being the url to external File holding the json
var r = new XMLHttpRequest();
r.open("GET", "external-file.json", true);
Should be:
function getViaAjax(url, callback) { // url being the url to external File holding the json
var r = new XMLHttpRequest();
r.open("GET", url, true);

I built up a quick sample that I can share that might help you isolate your issue. Stand this up in a local http-server of your choice and you should see JSON.parse(xhr.response) return a javascript array containing two objects.
There are two files
data.json
index.html
data.json
[{
"id":1,
"value":"foo"
},
{
"id":2,
"value":"bar"
}]
index.html
<html>
<head>
</head>
<body onload="so.getJsonStuffs()">
<h1>so.json-with-ajax</h1>
<script type="application/javascript">
var so = (function(){
function loadData(data){
var list = document.createElement("ul");
list.id = "data-list";
data.forEach(function(element){
var item = document.createElement("li");
var content = document.createTextNode(JSON.stringify(element));
item.appendChild(content);
list.appendChild(item);
});
document.body.appendChild(list);
}
var load = function()
{
console.log("Initializing xhr");
var xhr = new XMLHttpRequest();
xhr.onload = function(e){
console.log("response has returned");
if(xhr.status > 200
&& xhr.status < 400) {
var payload = JSON.parse(xhr.response);
console.log(payload);
loadData(payload);
}
}
var uri = "data.json";
console.log("opening resource request");
xhr.open("GET", uri, true);
xhr.send();
}
return {
getJsonStuffs : load
}
})();
</script>
</body>
</html>
Running will log two Javascript objects to the Dev Tools console as well as add a ul to the DOM containing a list item for every object inside the data.json array

jQuery dnd file upload for multiple targets

I'm using jQuery dnd file upload plugin for a project. All example of dnd uploader use id as a selector. For multiple items they used different dropzone declaration.
How can I change the plugin setting for multiple dropzone where the selector will be a class or something else to grab multiple elements with a single dropzone initiation?

Since this is using jQuery, couldn't you use the standard jQuery multiple selector method? It would look like this:
$("#drop1, #drop2, #drop3").dropzone();
Or if you are trying to do a class, you would do this:
$(".drop_zone").dropzone();
This isn't tested, and I have never used this plugin. I'm just assuming this would work since it is based off jQuery.
Since that isn't working, try replacing the code for jquery.dnd-file-upload.js with the following:
(function ($) {
$.fn.dropzone = function (options) {
var opts = {};
var uploadFiles = function (files) {
$.fn.dropzone.newFilesDropped(); for (var i = 0; i < files.length; i++) {
var file = filesi?;
// create a new xhr object var xhr = new XMLHttpRequest(); var upload = xhr.upload; upload.fileIndex = i; upload.fileObj = file; upload.downloadStartTime = new Date().getTime(); upload.currentStart = upload.downloadStartTime; upload.currentProgress = 0; upload.startData = 0;
// add listeners upload.addEventListener("progress", progress, false);
xhr.onload = function (event) {
load(event, xhr);
};
xhr.open(opts.method, opts.url); xhr.setRequestHeader("Cache-Control", "no-cache"); xhr.setRequestHeader("X-Requested-With", "XMLHttpRequest"); xhr.setRequestHeader("X-File-Name", file.fileName); xhr.setRequestHeader("X-File-Size", file.fileSize); xhr.setRequestHeader("Content-Type", "multipart/form-data"); xhr.send(file);
$.fn.dropzone.uploadStarted(i, file);
}
};
var drop = function (event) {
var dt = event.dataTransfer; var files = dt.files;
event.preventDefault(); uploadFiles(files);
return false;
};
var log = function (logMsg) {
if (opts.printLogs) {
// console && console.log(logMsg);
}
};
// invoked when the input field has changed and new files have been dropped // or selected var change = function (event) {
event.preventDefault();
// get all files ... var files = this.files;
// ... and upload them uploadFiles(files);
};
var progress = function (event) {
if (event.lengthComputable) {
var percentage = Math.round((event.loaded 100) / event.total); if (this.currentProgress != percentage) {
// log(this.fileIndex + " --> " + percentage + "%");
this.currentProgress = percentage; $.fn.dropzone.fileUploadProgressUpdated(this.fileIndex, this.fileObj, this.currentProgress);
var elapsed = new Date().getTime(); var diffTime = elapsed - this.currentStart; if (diffTime >= opts.uploadRateRefreshTime) {
var diffData = event.loaded - this.startData; var speed = diffData / diffTime; // in KB/sec
$.fn.dropzone.fileUploadSpeedUpdated(this.fileIndex, this.fileObj, speed);
this.startData = event.loaded; this.currentStart = elapsed;
}
}
}
};
var load = function (event, xhr) {
var now = new Date().getTime(); var timeDiff = now - this.downloadStartTime; if (opts.onLoadComplete) {
opts.onLoadComplete(xhr.responseText);
} $.fn.dropzone.uploadFinished(this.fileIndex, this.fileObj, timeDiff); log("finished loading of file " + this.fileIndex);
};
var dragenter = function (event) {
event.stopPropagation(); event.preventDefault(); return false;
};
var dragover = function (event) {
event.stopPropagation(); event.preventDefault(); return false;
};
// Extend our default options with those provided. opts = $.extend({}, $.fn.dropzone.defaults, options);
var id = this.attr("id"); var dropzone = document.getElementById(id);
log("adding dnd-file-upload functionalities to element with id: " + id);
// hack for safari on windows: due to not supported drop/dragenter/dragover events we have to create a invisible <input type="file" /> tag instead if ($.client.browser == "Safari" && $.client.os == "Windows") {
var fileInput = $("<input>"); fileInput.attr({
type: "file"
}); fileInput.bind("change", change); fileInput.css({
'opacity': '0', 'width': '100%', 'height': '100%'
}); fileInput.attr("multiple", "multiple"); fileInput.click(function () {
return false;
}); this.append(fileInput);
} else {
dropzone.addEventListener("drop", drop, true); var jQueryDropzone = $("#" + id); jQueryDropzone.bind("dragenter", dragenter); jQueryDropzone.bind("dragover", dragover);
}
return this;
};
$.fn.dropzone.defaults = {
url: "", method: "POST", numConcurrentUploads: 3, printLogs: false, // update upload speed every second uploadRateRefreshTime: 1000
};
// invoked when new files are dropped $.fn.dropzone.newFilesDropped = function () { };
// invoked when the upload for given file has been started $.fn.dropzone.uploadStarted = function (fileIndex, file) { };
// invoked when the upload for given file has been finished $.fn.dropzone.uploadFinished = function (fileIndex, file, time) { };
// invoked when the progress for given file has changed $.fn.dropzone.fileUploadProgressUpdated = function (fileIndex, file,
newProgress) {
};
// invoked when the upload speed of given file has changed $.fn.dropzone.fileUploadSpeedUpdated = function (fileIndex, file,
KBperSecond) {
};
})(jQuery);
This was suggested by the user rik.leigh#gmail.com here http://code.google.com/p/dnd-file-upload/wiki/howto