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Chrome Extensions, scope the local variable in.in.inside a function (from backgound.js )and use it globally (or in popup.js).

Recently I want to start a project by piggyback someone's extension. I want to scope one of the image source (local variable, a base64 url) and then photo recognize it on the popup page. I keep getting error "imgb64.replace is not a function" or "imgb64" not defined.
like my title said, I want to scope the local variable in.in.inside a function (from backgound.js )and use it globally (or in popup.js). very new to this, please help guys.
// this is popup.js
chrome.runtime.getBackgroundPage(function(bg) {
bg.capture(window);
});
/// what I did
function img_find() {
var imgs = document.getElementsByTagName("img");
var imgSrcs = [];
for (var i = 0; i < imgs.length; i++) {
imgSrcs.push(imgs[i].src);
}
return imgSrcs;
}
var imgb64 = img_find();
try {
const app = new Clarifai.App({
apiKey: 'mykey'
});
}
catch(err) {
alert("Need a valid API Key!");
throw "Invalid API Key";
}
// Checks for valid image type
function validFile(imageName) {
var lowerImageName = imageName.toLowerCase();
return lowerImageName.search(/jpg|png|bmp|tiff/gi) != -1;
}
var imageDetails = imgb64.replace(/^data:image\/(.*);base64,/, '');
console.log(imageDetails)
app.models.predict("e466caa0619f444ab97497640cefc4dc", {base64:
imageDetails}).then(
function(response) {
// do something with response
},
function(err) {
// there was an error
}
);
/// end what I did
below is background.js, I think what I need is the local var img.src, thats all.
function capture(popup) {
function callOnLoad(func) {
popup.addEventListener("load", func);
if (popup.document.readyState === "complete") {
func();
}
}
crxCS.insert(null, { file: "capture.js" }, function() {
crxCS.callA(null, "get", function(result) {
var scrShot, zm, bufCav, bufCavCtx;
function mkImgList() {
for (var i = 0; i < result.vidShots.length; i++) {
var img = new popup.Image();
img.onload = function() {
this.style.height = this.naturalHeight /
(this.naturalWidth / 400) + "px";
};
if (result.vidShots[i].constructor === String) {
img.src = result.vidShots[i];
} else {
bufCav.width = result.vidShots[i].width * zm;
bufCav.height = result.vidShots[i].height * zm;
bufCavCtx.drawImage(scrShot, -result.vidShots[i].left *
zm, -result.vidShots[i].top * zm);
img.src = bufCav.toDataURL('image/png');
////// maybe clarifai here ?
////end clarifai
}
popup.document.body.appendChild(img);
}
popup.onclick = function(mouseEvent) {
if (mouseEvent.target.tagName === "IMG") {
chrome.downloads.download({ url: mouseEvent.target.src,
saveAs: true, filename: "chrome_video_capture_" + (new Date()).getTime() +
".png" });
}
};
popup.onunload = function(mouseEvent) {
crxCS.callA(null, "rcy");
};
} /// end mkImgList
if (result.needScrShot) {
bufCav = popup.document.createElement("canvas");
bufCavCtx = bufCav.getContext("2d");
chrome.tabs.captureVisibleTab({ format: "png" },
function(dataUrl) {
scrShot = new Image();
scrShot.onload = function() {
chrome.tabs.getZoom(function(zoomFactor) {
zm = zoomFactor;
callOnLoad(function() {
mkImgList(zoomFactor);
});
});
};
scrShot.src = dataUrl;
});
} else if (result.vidShots.length) {
callOnLoad(mkImgList);
} else {
popup.document.body.appendChild(notFound);
}
}); // end crxCS.callA
}); // end crxCS.insert
} // end capture
Please help guys. :)

Nothings happens to the new element on page

I have following code, which highlights (fadein/out) the replied comment (its a div element).
I show only 10 last comments on the page
If the comment is found, then I highlight it (working fine), otherwise I load all comments and then try to highlight necessary one. But after loadAllComments function in the else clause the hide() method is not working - I wonder why.
function showReply(reply){
var p = getElement(reply);
if (p) {
$("#" + reply).animate({
opacity: 0.5
}, 200, function () {
});
setTimeout(function () {
$("#" + reply).animate({
opacity: 1
}, 200, function () {
});
}, 1000);
}
else{
loadAllComments(); //load all elements. working fine
$("#"+reply).hide(); //nothing happens. :-(
}
function loadAllComments() {
deleteComments();
$('.show-more-button').hide();
var xhr = new XMLHttpRequest();
xhr.open('GET', api_url + 'video_comments/?video=' + video_id, true);
xhr.withCredentials = true;
xhr.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
xhr.setRequestHeader("X-CSRFToken", $.cookie('csrftoken'));
xhr.onreadystatechange = function () {
if (xhr.readyState == 4) {
if (xhr.status != 200) {
alert(xhr.responseText);
}
else {
var comments = JSON.parse(xhr.responseText);
for (var i = comments.results.length - 1 ; i >= 0 ; i--){
$('.comment-content-box').append(showComment(comments.results[i]));
}
}
}
};
xhr.send();
}
function deleteComments(){
var comments_count = $('.comment-content-box').children('div').length;
for (var i=0; i < comments_count; i++){
$('.comment-render-box').remove();
}
}
function showComment(comment) {
return "<div>" // example, there is plenty of code, but it's just a return function
}

You're performing an XHR which is asynchronous. Supply a callback function to loadAllComments to be executed after your XHR completes:
function loadAllComments(callback) {
deleteComments();
$('.show-more-button').hide();
var xhr = new XMLHttpRequest();
xhr.open('GET', api_url + 'video_comments/?video=' + video_id, true);
xhr.withCredentials = true;
xhr.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
xhr.setRequestHeader("X-CSRFToken", $.cookie('csrftoken'));
xhr.onreadystatechange = function () {
if (xhr.readyState == 4) {
if (xhr.status != 200) {
alert(xhr.responseText);
}
else {
var comments = JSON.parse(xhr.responseText);
for (var i = comments.results.length - 1 ; i >= 0 ; i--){
$('.comment-content-box').append(showComment(comments.results[i]));
}
// xhr is complete and comments are now in DOM
callback();
}
}
};
xhr.send();
}
...
// usage
loadAllComments(function() {
$('#' + reply).hide();
});

Need to modify this onlinejs code (internet detection script) to fire manually, not on a timer

I am using the excellent onlinejs (https://github.com/PixelsCommander/OnlineJS) library for checking that my app has a live internet connection. However, I don't need it to fire regularly, but rather upon the manual calling of the main function.
I would like to modify this code so that it is not firing on a timer, and know the name of the function to call for manual firing, which assume is just getterSetter.
My previous attempts to modify the code below have broken the script as I'm no expert at JavaScript. I appreciate any help in adapting this very useful code.
function getterSetter(variableParent, variableName, getterFunction, setterFunction) {
if (Object.defineProperty) {
Object.defineProperty(variableParent, variableName, {
get: getterFunction,
set: setterFunction
});
}
else if (document.__defineGetter__) {
variableParent.__defineGetter__(variableName, getterFunction);
variableParent.__defineSetter__(variableName, setterFunction);
}
}
(function (w) {
w.onlinejs = w.onlinejs || {};
//Checks interval can be changed in runtime
w.onLineCheckTimeout = 5000;
//Use window.onLineURL incapsulated variable
w.onlinejs._onLineURL = "http://lascelles.us/wavestream/online.php";
w.onlinejs.setOnLineURL = function (newURL) {
w.onlinejs._onLineURL = newURL;
w.onlinejs.getStatusFromNavigatorOnLine();
}
w.onlinejs.getOnLineURL = function () {
return w.onlinejs._onLineURL;
}
getterSetter(w, 'onLineURL', w.onlinejs.getOnLineURL, w.onlinejs.setOnLineURL);
//Verification logic
w.onlinejs.setStatus = function (newStatus) {
w.onlinejs.fireHandlerDependOnStatus(newStatus);
w.onLine = newStatus;
}
w.onlinejs.fireHandlerDependOnStatus = function (newStatus) {
if (newStatus === true && w.onLineHandler !== undefined && (w.onLine !== true || w.onlinejs.handlerFired === false)) {
w.onLineHandler();
}
if (newStatus === false && w.offLineHandler !== undefined && (w.onLine !== false || w.onlinejs.handlerFired === false)) {
w.offLineHandler();
}
w.onlinejs.handlerFired = true;
};
w.onlinejs.startCheck = function () {
setInterval("window.onlinejs.logic.checkConnectionWithRequest(true)", w.onLineCheckTimeout);
}
w.onlinejs.stopCheck = function () {
clearInterval("window.onlinejs.logic.checkConnectionWithRequest(true)", w.onLineCheckTimeout);
}
w.checkOnLine = function () {
w.onlinejs.logic.checkConnectionWithRequest(false);
}
w.onlinejs.getOnLineCheckURL = function () {
return w.onlinejs._onLineURL + '?' + Date.now();
}
w.onlinejs.getStatusFromNavigatorOnLine = function () {
if (w.navigator.onLine !== undefined) {
w.onlinejs.setStatus(w.navigator.onLine);
} else {
w.onlinejs.setStatus(true);
}
}
//Network transport layer
var xmlhttp = new XMLHttpRequest();
w.onlinejs.isXMLHttp = function () {
return "withCredentials" in xmlhttp;
}
w.onlinejs.isXDomain = function () {
return typeof XDomainRequest != "undefined";
}
//For IE we use XDomainRequest and sometimes it uses a bit different logic, so adding decorator for this
w.onlinejs.XDomainLogic = {
init: function () {
xmlhttp = new XDomainRequest();
xmlhttp.onerror = function () {
xmlhttp.status = 404;
w.onlinejs.processXmlhttpStatus();
}
xmlhttp.ontimeout = function () {
xmlhttp.status = 404;
w.onlinejs.processXmlhttpStatus();
}
},
onInternetAsyncStatus: function () {
try {
xmlhttp.status = 200;
w.onlinejs.processXmlhttpStatus();
} catch (err) {
w.onlinejs.setStatus(false);
}
},
checkConnectionWithRequest: function (async) {
xmlhttp.onload = w.onlinejs.logic.onInternetAsyncStatus;
var url = w.onlinejs.getOnLineCheckURL();
xmlhttp.open("GET", url);
w.onlinejs.tryToSend(xmlhttp);
}
}
//Another case for decoration is XMLHttpRequest
w.onlinejs.XMLHttpLogic = {
init: function () {
},
onInternetAsyncStatus: function () {
if (xmlhttp.readyState === 4) {
try {
w.onlinejs.processXmlhttpStatus();
} catch (err) {
w.onlinejs.setStatus(false);
}
}
},
checkConnectionWithRequest: function (async) {
if (async) {
xmlhttp.onreadystatechange = w.onlinejs.logic.onInternetAsyncStatus;
} else {
xmlhttp.onreadystatechange = undefined;
}
var url = w.onlinejs.getOnLineCheckURL();
xmlhttp.open("HEAD", url, async);
w.onlinejs.tryToSend(xmlhttp);
if (async === false) {
w.onlinejs.processXmlhttpStatus();
return w.onLine;
}
}
}
if (w.onlinejs.isXDomain()) {
w.onlinejs.logic = w.onlinejs.XDomainLogic;
} else {
w.onlinejs.logic = w.onlinejs.XMLHttpLogic;
}
w.onlinejs.processXmlhttpStatus = function () {
var tempOnLine = w.onlinejs.verifyStatus(xmlhttp.status);
w.onlinejs.setStatus(tempOnLine);
}
w.onlinejs.verifyStatus = function (status) {
return status === 200;
}
w.onlinejs.tryToSend = function (xmlhttprequest) {
try {
xmlhttprequest.send();
} catch(e) {
w.onlinejs.setStatus(false);
}
}
//Events handling
w.onlinejs.addEvent = function (obj, type, callback) {
if (window.attachEvent) {
obj.attachEvent('on' + type, callback);
} else {
obj.addEventListener(type, callback);
}
}
w.onlinejs.addEvent(w, 'load', function () {
w.onlinejs.fireHandlerDependOnStatus(w.onLine);
});
w.onlinejs.addEvent(w, 'online', function () {
window.onlinejs.logic.checkConnectionWithRequest(true);
})
w.onlinejs.addEvent(w, 'offline', function () {
window.onlinejs.logic.checkConnectionWithRequest(true);
})
w.onlinejs.getStatusFromNavigatorOnLine();
w.onlinejs.logic.init();
w.checkOnLine();
w.onlinejs.startCheck();
w.onlinejs.handlerFired = false;
})(window);

Looking at the source, I believe you can simply call onlinejs.logic.checkConnectionWithRequest(false) to get the status synchronously. This function will return either true or false.
PS: I am sure there are better libraries for this task out there, I really do not like the way it's written and clearly, the author doesn't know JS very well. E.g., the following code taken from the library makes no sense at all.
w.onlinejs.stopCheck = function () {
clearInterval("window.onlinejs.logic.checkConnectionWithRequest(true)", w.onLineCheckTimeout);
}

XMLHttpRequest loop memory leak

I'm trying to check many items against information on ajax URL. But when I'm running this function in browser, memory usage goes above 2 gigs and then browser crashes (Chrome, Firefox). What am I doing wrong? items variable is really big - >200 000 and also includes some large strings.
var items = [1,2,3,4,5,6,7,8,9,10,...,300000]
var activeItems = {}
function loopAjax(){
for (i=0; i < items.length; i++) {
var currItem = items[i];
var request = new XMLHttpRequest();
var found = 0
request.open("GET", "/item=" + currItem);
request.onreadystatechange = function() {
if (request.readyState == 4 && request.status == 200) {
var response = JSON.parse(request.responseText);
var active = response[0].active;
if (active) {
console.log("FOUND ACTIVE! " + currItem);
activeItems[found] = {"active": true, "item": currItem};
found++;
}
}
}
request.send();
}
}

Thank goodness the browser stalls and dies. If it didn't you just created a denial of service attack!
The problem needs to be reapproached. You better off creating a state machine which has a stack of requests in it. That way you only doing say 5 concurrent requests at a time.
function ItemChecker(sample_size, max_threads) {
this.sample_size = sample_size;
this.max_threads = max_threads;
this.counter = 0;
this.activeItems = [];
this.isRunning = false;
this.running_count = 0;
}
ItemChecker.prototype.start = function start() {
this.isRunning = true;
while (this.running_count < this.max_threads) {
this.next();
}
return this;
};
ItemChecker.prototype.stop = fucntion stop() {
this.isRunning = false;
return this;
};
ItemChecker.prototype.next = function next() {
var request, item_id, _this = this;
function xhrFinished(req) {
var response;
if (req.readyState !== 4) {
return;
}
_this.counter--;
if (req.status === 200) {
try {
response = JSON.parse(request.responseText);
if (response[0].active) {
_this.activeItems.push({
active: true,
item: item_id;
});
}
} catch(e) {
console.error(e);
}
// When finished call a callback
if (_this.onDone && _this.counter >= _this.sample_size) {
_this.onDone(_this.activeItems);
}
}
else {
console.warn("Server returned " + req.status);
}
}
if (!this.isRunning || this.counter >= this.sample_size) {
return;
}
item_id = this.counter;
this.counter++;
request = new XMLHttpRequest();
request.onreadystatechange = xhrFinished;
request.open("GET", "item=" + item_id);
request.send();
};
ItemChecker.prototype.whenDone = function whenDone(callback) {
this.onDone = callback;
return this;
};
This might work? Didn't try it for real. But you would call it with:
var item_checker = new ItemChecker(300000, 5);
item_checker.whenDone(function(active) {
// Do something with active
}).start();

Second call out of two xmlhttprequest doesn't work

I've read a lot of how to try and make two xmlhttprequest in parallel, but it looks like something doesn't quite work.
I have 1 php file. which includes 2 .js files.
The first runs xmlhttprequest every 3 seconds.
I want the second to run on demand, but whenever i trigger it, it returns with status 4 but the responseText is always empty. (the PHP file prints with no question, i even tried to put on the PHP file just window.open('1') to see that the file is called and its not).
Here is the first JS :
var req1 = createXMLHttpRequest2();
var user_redirected = false;
function createXMLHttpRequest2() {
var ua2;
if(window.XMLHttpRequest) {
try {
ua2 = new XMLHttpRequest();
} catch(e) {
ua2 = false;
}
} else if(window.ActiveXObject) {
try {
ua2 = new ActiveXObject("Microsoft.XMLHTTP");
} catch(e) {
ua2 = false;
}
}
return ua2;
}
function set_user_redirected_false() {
user_redirected = false;
}
function get_user_redirected() {
return user_redirected;
}
function handleResponse(username, game_id, isInvitation) {
if(req1.readyState == 4 && req1.status==200) {
var response = req1.responseText;
if (response == "true") {
// Ask to set the game_accepted var to 1 (user is redirected and not leaving)
user_redirected = true;
if (isInvitation == "true") {
window.location.href = "game.php?game_id="+game_id+"&position=2";
} else {
window.location.href = "game.php?game_id="+game_id+"&position=1";
}
}
else {
setTimeout(function(){sendRequest();}, 3000);
}
}
}
function sendRequest() {
user_redirected = false;
var username = "";
var game_id = -1;
var isInvitation = "false";
username = document.getElementById("username").value;
game_id = document.getElementById("game_id").value;
isInvitation = document.getElementById("invitation").value;
if (isInvitation == "true") {
req1.open('GET', 'check_for_inviter.php?username='+username+'&game_id='+game_id ,true);
} else {
req1.open('GET', 'check_for_opponent.php?username='+username+'&game_id='+game_id,true);
}
req1.onreadystatechange = function(){handleResponse(username, game_id, isInvitation);};
req1.send(null);
}
This is the second JS file :
function createXMLHttpRequest() {
var ua;
if(window.XMLHttpRequest) {
try {
ua = new XMLHttpRequest();
} catch(e) {
ua = false;
}
} else if(window.ActiveXObject) {
try {
ua = new ActiveXObject("Microsoft.XMLHTTP");
} catch(e) {
ua = false;
}
}
return ua;
}
function delete_waiting_games(username) {
var req2 = createXMLHttpRequest();
req2.open('GET', 'delete_waiting_games_for_username.php');
req2.onreadystatechange = function(){
window.open(req2.readyState+'&'+req2.responseText);
};
req2.send(null);
}
As you can see i open a new window to see the response and the ready state (just for testing) and i always get status 4 and empty responseText.
Thanks.

Use setTimeout to separate the calls, and with to encapsulate the XMLHTTPRequest:
function xhr()
{
with(new XMLHttpRequest)
{
open("GET",{},true);
setRequestHeader("Foo", "Bar");
send("");
onreadystatechange = handler;
}
}
function handler(event)
{
!!event.target && !!event.target.readyState && event.target.readyState === 4 && ( console.log(event) );
}
setTimeout(xhr, 500);
setTimeout(xhr, 1000);