How to see the steps of calling javascript functions in Firebug - javascript

I'm working with JVectorMap and I have made some changes on the code as well.
the program works well but I don't know why when I'm rendering the map two request for rendering the page send to my servlet.
everything seems ok and I didn't call my rendering servlet code twice but I don't know why two request come to my servlet.
I supposed that may be a refresh request while rendering, somewhere but I couldn't find any, I want to check the process of rendering my page step by step to figure out what the problem is but It seems debugging the javascript is a cumbersome task and I don't know how in firebug I can check each part of my code step by step as I have some javascript file imported as well.
do you have any suggestion or idea ?

On the script tab of firebug click at the line where you want to stop execution.
Alternatively you could insert debugger; instruction in your code.
Then use buttons on the top of script tab. If you don't know how - google for "debugging javascript with firebug".

Related

Debug Javascript in Android WebView from same app

I'm experimenting with a simple Javascript debugger for a WebView. I'd like to debug/control/inspect how some Javascript code is being executed inside my WebView.
I haven't found any solution other than using the WebChromeClient to receive the console messages.
Since I have access to the Javascript code I can add instrumentation code: a console.log call before each line, with a special message (e.g. "debugging line 3") that tells which lines have been executed.
It's quite rudimentary so I wonder if there's any better solution. It would be great if I could use the debugger statement to really control execution flow.
This is what I have been doing if I want to console.log() anything directly on the mobile browser so that debugging can be done on the actual device and not in emulator or similar...
I made JS debugger plugin and here is what it have:
it creates an absolutely positioned HTML element that is placed on top of the content and is semi transparent.
I made the JS logic that actually simulates what console.log() does and print out all desired information in mentioned HTML element
once plugin was done I simply used MoibileDebugger.log('what ever'); instead of console.log('what ever');
My code is still not published publicly but will do that soon, so that anyone can benefit from using it...
In any case this plugin can be made very quickly by anyone who is good in JS.

Export Flash parameters to JavaScript

I'm trying to pass parameters from Flash (as 3.0) to JavaScript.
Tried all methods I found in via. Google, as:
ExternalInterface.addCallback ("fonts", recieveFromJS);
Always one and the same problem; when I try to call the fonts () swfobject, JavaScript gives the error that the method doesn't exist.
Assuming your javascript code does not have a syntax error somewhere, this usually happens because of jquery (or some other js bundle) is stepping on your code. Try using a test page with just the javascript you need, removing all other code and header entries. If it works, then add scripts and links back, one at a time, and you will find which code is breaking it. If it does not work even in your test page, then you have a code/syntax/logic problem with the snippet of code you are working with. If you still have a problem with a code snippet, post it here and I or someone will surely help debug it for you.

Save and load entire web page state (Visual HTML, And javascript Variables)

So lately I've been working on this project, which will end at the end of January (end of this week).
http://www.nikollr3.three.axc.nl/ (this is a preview of the program a few months ago, but u get an idea)
We have started testing the website and noticed that it was sometimes making Firefox crash.. since Firefox' error or crash reports were never of any use (no useful information found), I have no idea how to fix this error. And a possible solution would be to have a save / load button on the web page, which can save or load a state (and for example autosave state untill it crashes) then when it crashes you would be able to reload the last state and continue working on the project. By saving a 'state' I mean recreating the EXACT moment as to when the save button was clicked, thus same javascript variable values and same HTML looks.
I have found little things about this on the internet, the only one relevant being for android phones,.. Any ideas or implementations?
write all your variables and "HTML looks" (attributs) to a XML-file. load (if (exist(XML)pseudo-code) all necessary data onPageLoad

Getting data from the browser's console using javascript

I don't know if this has been asked before, but what i'd like to be able to do is get data from the error console within the browser itself(if it supports it) this would be for when a user sends off a bug report it'd pull up any errors related to pages at my website for things such as typos in code and other things that somehow managed to slip by. Also, in that regard is there a way to pass the errors from the console to a useable format? If this isn't possible, then i could just tell them to copy and paste what came up from the site itself.
I thought of this right now as i was thinking about how to make the bug reporting system run better since the entire thing is basically ran within the browser and for the backend I can easily just look at error logs but for the frontend ie javascript bits of things it's not goign to be as easy.
So to finish wrap all of this up in one little statement, is there an easy way to get the data from the error console and be able to send it along via javascript ie to a form, or something similar.
You can use the onerror event in JS to get the details of the error. Hoptoad do this for example and log the errors to their console, Their code re-uses lots of nice JS scripts including a printStackTrace function that is great.....
You can see how they do it here:
http://hoptoadapp.com/javascripts/notifier.js

'$ is not defined' in code following jQuery include

I'm getting the familiar '$ is not defined' error in my JavaScript for the following line in one of my javascript files...
$(document).ready(function() { … }
Normally this is because I've forgotten to include jQuery, but not this time! I have included it, and it is the first include in the page. This error happens in included JavaScript files, and also in any code within tags, all of which come after the jQuery include. It also doesn't happen all the time, maybe half the time when I refresh the page.
I've also used jQuery quite a lot and never seen this before, so I am quite confused.
Edit:
Looking at the Net tab in Firebug, jQuery is being requested and I get a 200 response but nothing is sent back in the response body. If I open the file directly in a new tab or whatever, I get an empty document. Firefox seems to think the file is cached but the data size is 0. Cache control is 'no-cache'. Confused.
Edit 2:
Opened jQuery file in VisualStudio, saved jQuery file with no modifications, everything works perfectly now. Still totally confused.
Are you sure that jQuery is actually being loaded into the browser? It sounds like it really isn't. You should use Firebug or Fiddler to check all the http requests to see if it is actually being downloaded.
Here's a screenshot of how you can check this using Firebug.
Are you using Wordpress or some sort of CMS? If so, their version of jQuery may have of code at the end which calls jQuery.noConflict(). You can read about this method here: http://api.jquery.com/jQuery.noConflict/
This means that whenever you want to use the $ function, you need to use jQuery instead.
For example...
Instead of
$("p").addClass("awesome");
You would do
jQuery("p").addClass("awesome").

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