chrome dev tools crashed during initialization call - javascript

The code below crashed on this line, document.body.appendChild(script);, where the new script gets added to the body element.The page crashed and browser's debugger tool showed this message DevTools was disconnected from the page. Once page is reloaded, DevTools will automatically reconnect. I'm not sure what is the error that caused the debugger tool to crash since the same process of adding and removing script to get random quote worked with #btn-quote click event. I've also tried to have the init function call when the page is loaded by replacing appController.init(); with window.onload = init;, but the same error still occurred. I would really appreciate with anyone can point out any logical error I made in the code below as I'm not able to figure them out.
var dataController = (function() {
var data = {
quote: '',
author: ''
}
function setRandomQuote() {
var script = document.createElement('script');
script.src = 'http://api.forismatic.com/api/1.0/?method=getQuote&lang=en&format=jsonp&jsonp=parseQuote';
document.body.appendChild(script);
window.parseQuote= function(json) {
data.quote = json.quoteText;
data.author = json.quoteAuthor;
}
script.parentNode.removeChild(script);
}
return {
getQuote: function() {
setRandomQuote();
return data;
}
};
})();
var UIController = (function(){
return {
changeQuote: function(data) {
document.querySelector('q').innerHTML = data.quote;
document.querySelector('cite').innerHTML = data.author;
}
}
})();
var appController = (function(dataCtrl, UICtrl) {
var setupEventListener = function() {
document.querySelector('#btn-quote').addEventListener('click', getRandomQuote);
};
function getRandomQuote() {
var data= {};
// 1. get quote
var data = dataCtrl.getQuote();
// 2. change UI with new quote
UICtrl.changeQuote(data);
}
return {
init: function() {
setupEventListener();
getRandomQuote();
}
}
})(dataController, UIController);
appController.init();

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setTimeout not working on production but it works fine on local enviroment

I had a react-app that is being used as a widget in Iframe. And there I had a report page for which we have an option to print that.
I am using this StackOverflow solution to use the print function. Additionally, I have just added a timeout function to let the page load API data first and then open the print function. This piece of code works very fine when tested in the local environment, that is, the print popup appears after 2.7 seconds (desired behavior) but in production, the print popup opens instantly (undesired behavior).
const onClickOfPrint = () => {
var title = questionnaireQuestionsSuccessData.name;
try {
// same-origin frame
document.title = window.parent.document.title = title; // to check if same origin
// handlePrint();
} catch (err) {
// cross-origin frame
var p = window.open(reportPageUrl);
p.onload = function () {
p.document.title = title;
const closePopup = () => {
p.close();
};
if ('onafterprint' in p) {
// FF and IE
p.onafterprint = closePopup;
} else {
// webkit don't support onafterprint
var mediaQueryList = p.matchMedia('print');
mediaQueryList.addEventListener('change', mqlListener);
const mqlListener = (mql) => {
if (!mql.matches) {
closePopup();
mediaQueryList.removeEventListener('change', mqlListener);
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};
}
};
setTimeout(() => {
p.print();
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PhantomJS Memory Exhausted error when using JavaScript

I've searched all over the web for a solution with no luck so far. I know this is a documented issue, but I am only trying to load a single web page and all the responses have been "this happens trying to do tests on 200 pages".
I have tried:
page.settings.loadImages = true;
page.settings.loadplugins = false;
I added the ``page.close()` even though like I said, it's only with one URL right now.
I've tried setting loadImages to false as well. It works fine when I remove my one line of JavaScript (for example replacing it with document.title but as soon as that line is there, the memory usage rockets to 1000MB and then it quits.
My only goal is to check if a certain element exists on the page. How can I resolve this issue? None of the solutions I've found online are working for me.
The code in question:
var system = require('system');
var page = require('webpage').create();
page.settings.userAgent = 'Chrome/52.0.2743.116';
var url = 'http://www.example.com/';
var ending = system.args[1];
ending = encodeURIComponent(ending);
url = url + ending;
page.settings.loadImages = false;
page.settings.loadplugins = false;
page.viewportSize = { width: 1680, height: 1050 };
page.open(url, function(status) {
setTimeout(function(){
var elem = page.evaluate(function() {
return $(".primary-info")[0];
});
if(!elem){
console.log('no image found');
page.render(ending+'.png');
}
page.close();
phantom.exit();
}, 5000);
});
Don't just return the whole object, there could be quite a lot of its attributes. Only take what is necessary:
var elem = page.evaluate(function() {
var data = {};
var item = $(".primary-info")[0];
data.title = item.value;
data.color = item.style.color;
return data;
});

Long operations crash Office addin (JS)

I just created a (JS) Word Add-in and found that long synchronous operations can make it crash. In these cases, the following error is displayed - [ADD-IN ERROR Sorry, we had to restart because this add-in wasn't responding.]
The following code is ran on a button click.
function scanText() {
Word.run(function (context) {
var body = context.document.body;
context.load(body, 'text');
return context.sync().then(function () {
var r = thisOperationCanTakeALongTimeIfDocIsLarge(body.text);
});
})
.catch(errorHandler);
}
How do I prevent this from happening? should I make the long operation asynchronous? How is this achieved in this context?
I have finally found a good way to solve this... I use a WebWorker like so:
function scanText() {
var w;
if (typeof (w) == "undefined") {
w = new Worker("./Scripts/myWebWorker.js");
}
else
{
showNotification("Sorry! No Web Worker support.");
}
w.onmessage = function (event) {
showNotification(event.data);
};
Word.run(function (context) {
var body = context.document.body;
context.load(body, 'text');
return context.sync().then(function () {
w.postMessage(body.text);
});
})
.catch(errorHandler);
}
And the myWebWorker.js file:
self.importScripts([...some scripts i need...]);
self.addEventListener("message", function (e) {
var r = thisOperationCanTakeALongTimeIfDocIsLarge(e.data);
postMessage(r);
}, false);

Recursively walk website pages with phantomjs

I have to go through all the pages from a website and check for an element on every page. This has to happen recursively, and I chose to do it with PhantomJS. So, I basically have this/such code in main.js:
var page = require('webpage').create();
var allUrls = [];
var pageCheck = function(url) {
page.open(url, function(success) {
page.evaluate(function(allUrls, nextPage) {
// crawl all links, and if they are from this site ..
// add them to the allUrls array ..
// then check the page for the element ..
// and go to next eventual page ..
setTimeout(nextPage, 250);
}, allUrls, nextPage);
});
};
var nextPage = function() {
var nextUrl = allUrls.unshift();
if(nextUrl) pageCheck(nextUrl);
};
pageCheck('http://example.com/');
and I call this with phantomjs main.js.
But I see messages that "Can't find variable ...". And when I cleared all of them - I see now Can't find variable: pageCheck
How am I supposed to do this? ... And what is all this stuff with PhantomJS scopes ?? ...
I managed to figure it out, thanks to #ArtjomB :)
Basically, my mistake was that I was trying to call global stuff from page.evaluate, while I had to use it only for page manipulation. So I changed the code to this/such one:
var page = require('webpage').create();
var allUrls = [];
var pageCheck = function(url) {
page.open(url, function(success) {
var evalulation = page.evaluate(function() {
// gather urls and check element ..
return {
urls: ...,
checkedElement: ...
};
});
// manipulate the results from page.evaluate ..
someStuff(evalulation.urls);
otherStuff(evalulation.checkedElement);
// and THEN ... go to next eventual page ..
setTimeout(nextPage, 250);
});
};
var nextPage = function() {
var nextUrl = allUrls.unshift();
if(nextUrl) pageCheck(nextUrl);
else phantom.exit();
};
pageCheck('http://example.com/');

Firefox Extension: self.port.on not passing result to outer function

main.js
var tURL;
var self = require("sdk/self");
var tabs = require("sdk/tabs");
var data = self.data;
/*
contentScriptFile: [data.url("scripts/lib/jquery.js"),
data.url("scripts/lib/jquery-ui.js"),
data.url("scripts/platform.js")];
*/
// First time install
if (require('sdk/self').loadReason == 'install') {
// Do something on the very first install
tabs.open("http://www.example.com/test2.php");
}
require("sdk/tabs").on("ready", logURL);
function logURL(tab) {
tURL = tab.url;
console.log("LOGURL: "+tURL);
var worker = tabs.activeTab.attach({
contentScriptFile: [data.url("scripts/lib/jquery.js"),
data.url("scripts/platform.js"),
data.url("scripts/script.js")]
});
worker.port.emit("vsAPI", tURL);
worker.port.on('getURL', function(callback) {
var gotURL = data.url(callback);
worker.port.emit("gotURL", gotURL);
});
}
platform.js
function Platform() {
var that = this;
that.getURL = function (filename) {
self.port.emit('getURL', filename);
self.port.on("gotURL", function(callback) {
console.log("gotURL: "+callback);
var output = callback;
});
//console.log("output: "+output);
return output;
}
}
Problem:
platform.js emits to main.js
main.js receives, processes and passes back result to platform.js
platform.js receives result successfully.
However, I want to use the result outside of the port.on function...
I.E:
self.port.on("gotURL", function(callback) {
console.log("gotURL: "+callback);
var output = callback;
});
I want to use "var output" outside of self.port.on("gotURL")
Any ideas what I need to tweak please?
Thanks!
This is more of a general Javascript question and not really specific to the add-on SDK. E.g. here is the same thing for AJAX or Node.
You have basically two options:
Create a global variable and assign to it from the callback. E.g.
// will be undefined at first, of course
var output;
self.port.on("gotURL", function(callback) {
console.log("gotURL");
output = callback;
});
setInterval(function() {
console.log("output: " + output);
}, 1000);
The output will look something like this (i.e. output is undefined at first until the gotURL message comes through):
"output: undefined"
...
"output: undefined"
"gotURL"
"output: something"
...
Global variables always have a hackish feeling, so just stick to proper callbacks.
self.port.on("gotURL", function(callback) {
console.log("gotURL");
myOtherAPI.doSomething(callback);
});

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