Is there a web developer functionality/tool that allows us to know how many times a browser is doing reflows?
basically I want to have some sort of feedback/information. I don't know how it will be, but perhaps some sort of performance graph that shows the timeline (akin to Google's Speed Tracer) so I can investigate when suddenly at a point the browser is doing an insane amount of reflows so I can point out hey here's a bottleneck, there got to be a bug/bad implementation of something here or something.
Chrome and Safari have Timeline tab in Web Inspector where you can see all the reflows and redraws made by browser.
Firefox has MozAfterPaint event. It can help you understand which regions of the page and when repainted by the browser. Firebug Paint Events add-on can be helpful here. It shows repaint events in FireBug console.
You can track reflow information if you have a custom built Firefox.
see below:
https://developer.mozilla.org/en-US/docs/Debugging_Frame_Reflow
How to build Firefox with enable debugging mode:
https://developer.mozilla.org/en-US/docs/Developer_Guide/Build_Instructions
Sometime after late 2013, the reflow logging is built into Firefox logging.
https://mail.mozilla.org/pipermail/firefox-dev/2013-October/001044.html
In browser console (Tools > Web Developer > Browser Console), in the [CSS] menu, select "Log"
Related
I'm trying to debug a CMS-backed website (Drupal 7). It is displaying some problems due to conflicting Javascript. For a fraction of a second, the site components are fine, and then *SNAP*, they're broken. It must brake as soon as the conflicting resource loads.
Using Chrome's developer tools (or Safari, Firefox... even IE's), is there a way to load the page, one Javascript resource at a time? This way I can see exactly which resource loads when the page issues appear.
(I'm also open to better ways of debugging this kind of thing.)
You can use the Pause on exceptions feature of DevTools, in Sources Tab, it is the hexagonal pause button at the far right.
I've got a page that takes about 15 seconds to load, due to a few loops I have going on, cloning DIVs and loading content into them. Is there some way in the Chrome inspector that I can easily see where the hold-up in my script is?
EDIT: I tried the 'Profiles' tab in the inspector, but it doesn't show my actual script. It shows the jquery.js source code which is not useful.
Look at the Profiles tab of the inspector. note: this is webkit only
More information on the specific browser profilers can be found...
Chrome: https://developers.google.com/chrome-developer-tools/docs/profiles
FireFox: http://getfirebug.com/javascript
Opera: http://dev.opera.com/articles/view/opera-developer-tools/
Even IE has dev tools: http://blogs.msdn.com/b/ie/archive/2008/09/11/introducing-the-ie8-developer-tools-jscript-profiler.aspx
at the beginning of what you want to inspect put:
var startTime = new Date().getTime();
and at the end:
console.log(new Date().getTime()-startTime)
If the problem is related to the performance of javascript then Profiles tab in Safari WebInspector or Chrome DevTools will help you.
The difference between them in the profiling code for Safari JSC and Chrome V8.
JSC has Instrumenting profiler, V8 has Statistical profiler.
The first one is more precise, the second less affects the performance of the page.
The UI is the same in Safari and Chrome.
There is two different sort orders for the profiling data.
Heavy (Bottom Up) and Tree (Top Down). You can change it in the combo-box at the bottom of Profiles page.
If the most time consuming entry is the '(program)' then I'd recommend to use Timeline Panel.
Chrome version of Timeline Panel provides more information.
After updating Google Chrome browser to the latest 15.0.874.106 version (under Windows 7), my site is experiencing some weird flickering bug.
The text shadows are displaying completely wrong, the text itself is fuzzy and unclear, some parts of code don't work anymore (e.g. right floating, fixed menu)... etc.
For a couple of seconds the site is displayed fine, then it flickers all of the sudden (while still loading) and then the rendering gets messed up. (I think it has maybe some problems with loading of Google Maps v3)
The funny thing is that the old version of Chrome (before updating, on my other computer) is still displaying the site without any problems, and there haven't been any changes in the code in the meanwhile.
In other browsers (as i said, even in the old chrome) everything is OK. Firebug and Chrome's code inspector (CTRL+SHIFT+J) don't show any errors in the code. I have been doing some digging on the Internet and here as well, and I havent't found anything useful.
You can check it out by yourself by clicking here
Thanks in advance.
I have done same settings changes as mentioned above post and now, that weird flicker got stopped, below are the details....
Open Chrome Browser
Click on Settings menu option
Click on Advance setting link in Settings page
Un-Check "Use Hardware acceleration when available" checkbox
Restart you chrome browser
Happy Browsing....... :)
Also make sure to disable not only accelerated-compositing, but also accelerated-2d-canvas.
This is how I start google-chrome on Linux:
/opt/google/chrome/google-chrome %U --user-data-dir=/root --disable-accelerated-compositing --disable-accelerated-2d-canvas
On Windows, you might want to omit
--user-data-dir=/root
Josip Filipović apology where to do that (in Win7 by entering -disable-accelerated-compositing in properties > target field) that part disables hardware acceleration.
We did an application using rails(2.3.4), ruby(1.8.2), MySQL, JavaScript, jQuery. This is handling minimum 6000 records. We showing those records detail in table. In the beginning Mozilla taking 2m to load the whole page. We did the cache, eager loading, indexes. Now Mozilla taking 25s to load the whole page. But IE-7 taking 1m30s to load the page.
We don't know why IE-7 taking too much of time.
Any one can help us to detect the running time in IE-7 and tell your guidelines to improve performance in IE-7.
Any add-on is available in IE7 to see the AJAX request time taken as like Firebug add on.
Use partial loading. Don't try to load the 6000 records at once, load them in smaller segments, when needed. Even 5 second loading is too long, not to mention the 25 seconds or 1m 30s.
Oh and yeah, IE 7's JS engine just sucks.
From Table Rendering - IE Blog:
When Internet Explorer encounters a table it measures all the content
of the table before rendering so that it knows what the widths of the
columns are to render the content correctly. On the other hand Firefox
uses a different algorithm in that it renders the table contents
progressively before it has all been passed.
You can improve performance by setting the CSS rule table-layout: fixed. The renderer will then calculate the layout based on the first row of the table.
IE7 is slow, there's no real way of getting around that basic fact.
I'm going to answer your second question (about debugging tools for IE7) because I don't think I can give any useful advice on your main point about actually speeding up IE7.
Any add-on is available in IE7 to see the AJAX request time taken as like Firebug add on.
The first thing to try is IE8 or IE9. These browsers have a Developer Tools window (accessible via F12, just like Firebug). It isn't as good as Firebug, but it does do quite a bit, and it is a useful debugging tool. It also has a feature which allows you to switch the browser into IE7-compatibility mode. The idea is that you can test IE7 from the relative comforts of IE8 or IE9.
The down side is that it isn't actually IE7. It's just a pretend ID7, and not a particularly good one at that. It may or may not replicate the speed issues you're having with IE7, and it certainly has known bugs and quirks of its own which don't appear either in a real IE7 or in IE8 in normal mode.
But all that said, it might be good enough for you to run some tests and get some answers.
A second suggestion might be to try Firebug Lite. This is a cut-down version of Firebug which runs as a bookmarklet in any browser (but generally IE). It doesn't have all the features of the full version of Firebug, because there's only so much you can do without writing a browser plug-in, but it does do a surprising amount. If nothing else, it does give you the console functions, which can be a life saver for debugging.
I hope that helps.
I have a site that uses javascript to launch a css overlay of a google map (see [link deleted because I can only have one at a time] and click the 'Enlarge' button under the map).
This doesn't work on the ipad. I believe it has something to do with this not being a link, but using the jquery live('click',.. approach. I need to fix this but I'm new to using the ipad and I don't even know how to step through the javascript to see what the problem is.
What kind of development tools are available for testing on the ipad?
Edit: My mistake. The link above works fine in the iPad - no problem bringing up the larger map. However the sister site http://lowes-realty.com/Stateline-Plaza_Enfield_CT-11.aspx is not working. What I need is a development system that will let me look at them both on the ipad (I really want to avoid emulating or spoofing).
Have you tried firebug lite?
http://getfirebug.com/firebuglite#Install
Have you tested this in google chrome? As google chrome is a webkit browser, you may be able to do the majority of your debugging in chrome, and iron out smaller issues on the iPad itself.
Edit:
Removed unnecessary comment about iPad.
The problem ended up being that I had a javascript error that aborted the script before I ever got to the jQuery code. Once I fixed that, I was able to use jQuery without making any special modifications for the ipad - awesome! I did not have to do anything with the swipe or tap events (sweet!).
However I was not able to get any kind of javascript debugger; I had to work this one out for myself. As of Nov '09 firebug lite crashed the ipad for me and there don't seem to be any developer tools build for testing the ipad. I tried several sites that claimed to perform the same way the ipad does in your browser and not one of them held water.
I have no reason to believe that there is a good option for debugging a site on an ipad (yet).
Edit A Year Later... I'm still looking for a good way to develop on an iPad. I just got Adobe Shadow up and running - it's not actually a useful tool, but there is potential (http://tv.adobe.com/watch/adobe-technology-sneaks-2012/adobe-shadow). Right now (3-29-12) the code inspector is essentially non-functional (cannot view inherited styles, can't view elements without expanding the DOM from the body element, no javascript debugging, and much more).
I know that sounds hopeless, but it has one thing going for it that nothing else I'm aware of does: Shadow works with all existing mobile devices and its code inspector is independent of device and browser. So although the inspector sucks spectacularly right now, once they build some functionality into it Shadow could be a good solution. From their site:
Shadow will be updated regularly to stay ahead of web standards, web
browser updates and support for new mobile devices entering the
market, while incorporating user feedback to provide the best
functionality and experience possible.
~ http://labs.adobe.com/technologies/shadow/
I think the problem is that on the iPhone / iPad there are no clicks events generated but instead touch events (swipe, tap).
You can use something like jQTouch (you can start reading here Getting started and then proceed to callback events hint: tap==click).
If you have more to adapt you can also look at (and wait for a stable release) of jQuery Mobile
weinre lets you remotely attach a WebKit inspector (the built-in Dev Tools you use on desktop browsers) to a page running on your mobile device (iPad/iPhone/iPod/Android/BlackBerry 6/webOS) over WiFi.
http://phonegap.github.com/weinre/images/weinre-demo.jpg
JavaScript debugging is limited to console.logs, but it's better than nothing.
If you have an ICS device, Chrome Mobile lets you remotely attach a full-featured Inspector (with full JS debugging/breakpoints) over USB. I've been thoroughly thrilled using this tool with my Galaxy Nexus.
(source: google.com)