Slide for Code Camp 14

Haven't been doing technical blogging for a while after having second kid :)

I still owe people a lot of blog posts :)

Here is the presentation for last year Code Camp

Javascript Testing with Jasmine

Slide and github for Code Camp 13

Thank you for attending this afternoon session, hopefully you guys at least get some basic knowledge on Backbone and how each component interact with each others.

I hope we could have internet access today, so we all can get some hands on experience by going through the github code together. So please feel to checkout the code, follow the instruction and set it up in your local environment.   Feel free to poke around. 

https://github.com/iroy2000/backbone-tutorial

I will update the slide later, you should get the slide on the code camp official website later as well.

Update
======
There is a question about if there is a user preference concept for an application, and what the user preference will do is adding some filtering for a screen ( Let say stock quote view ).

There are plenty of ways to do that, but one of them I would see is
1) assume you have a user/ api
2) assume you have a stock-quote/ api

What usually is done should be in this sequence
1) You will fetch the user/ api first, because your other view or section has dependency on it
2) Grab what you need from the user api response, let's say your user has a preference of showing top 10 stock for each day
3) Now you can fetch the stock-quote/ api by passing some filter parameter that your user set earlier, for example,  /stock-quote/?display_top_transaction=10

Automated Performance Testing with CasperJS

This is currently just a hobby script, but could potentially turn into a very useful performance automation testing framework.

Recently I have integrated a Spider into the Casper netsniff script, and what it does is when you pass the spider an entry point of your site, and it will go through all the pages, capture screenshot and generate har file for all your individual pages.

For more info about this project, please visit
https://github.com/iroy2000/casper-netsniff-spider

Here are some screenshots

CasperJS netsniff.js

Recently I was playing around with PhantomJS and like this testing framework a lot.  And then two days ago I saw in some forum posts that people recommended to use CasperJS ( built on top of PhantomJS ) which provide site navigation functionality. So I started playing around with CasperJS.

And then one day later, which is this morning, I was trying to think about using phantomJS netsniff.js script in CasperJS, and I google it like "How to use the phantomjs example netsniff.js inside casperjs", and there is not much results, all of them are talking about PhantomJS netsniff. Then I also search in the CasperJS google group and found that there some people actually are asking the same question.  Without finding any results further, I finally take the PhantomJS version and convert it for CasperJS.

Here is the github link:

https://github.com/iroy2000/casperjs-netsniff

Hope it helps those who have the same issue. Enjoy!

Note: I'm working on a customized version where you can generate har file when you navigate around the sites in your Casper tests.

Please leave me message if you have any comments.  Thanks!

Just Another Frontend Boilerplate

Recently put together a frontend boilerplate with some latest 3rd party libraries makes into a checkout-and-ready-to-use boilerplate.  It has a configured built tool which you can use right away.  Also, it comes with a customize micro framework which you can take advantage of, but you can replace it with your own easily.

For more information, go to https://github.com/iroy2000/frontend-boilerplate

Frontend Boilerplate

This frontend boilerplate includes a customized mirco framework that combines some of the latest frontend library in the market. It comes with Jasmine as testing framework, plus build tool and build config.

Libraries Included

• Backbone ( amd )
• Backbone Localstorage
• Underscore ( amd )
• Twitter Bootstrap
• Require-jQuery
• Text ( RequireJS Plugin )
• Modernizr
• HTML5 Bolierplate ( partial )

IE error on feeding array of HTML elements to jquery html()

I was debugging a seemingly simple issues in IE ( but it turns out could be an inconsistent in javascript implantation ), which unsurprisingly works in other browsers.  When I trace the error, it was coming from the jquery library, and in which there is a native function call fragment.append(elem)

And this is my guess - the implementation of append() in IE doesn't really support an array of elements. Maybe I'm wrong, please let me know if that's a wrong guess.

There are so many ways to fix it, but one simple way is do a 'join' on your array before feeding to the jquery html()  function to append stuff.

Bootstrap Modal browser resize issue

If you are using Bootstrap Modal  and when you resize your browser size to small enough, your modal will get cut off and you have no way to access the modal footer.

Try the demo in their page, click the demo link and resize your browser, you won't be able to access the button in the modal anymore.
http://twitter.github.com/bootstrap/javascript.html#modals

There may be several ways to solve this, one of them, we found the cheapest is using "media query" in css3, and there are some polyfills to make IE understand "media query".

And you can do something similar to below ( just example, make changes to fit your need )


/* create a rule for height that is smaller than 600px */
@media screen and (max-height: 600px) {
    /* make sure modal shrinks with the browser  */
    .my_dialog .modal-body, .modal-body {
        max-height:300px;
        overflow-y: scroll;
    }
}

What above does is to make the modal body size smaller when the screen size shrink to less than the max height that defined, and it will make the modal body scrollable.

But there are more than one way to fix the problem, this is just one of them.  Hope this helps :)

A great collection of App performance articles

This is a blog post quote from other people, but want to put it here as self reference in the future and in the hope that it will help more people. 

There have been some great app performance resources surfacing recently, so I thought it would make sense to do a roundup.

I've recently seen apps whose performance is being crushed by large & expensive paints, extra layouts, bad event decoupling or too many network requests. They are all fixable items, and Chrome's DevTools and tracing tool both do a great job of showing you what's going on under the hood.

Web Performance Power Tool: HTTP Archive (HAR)

A rundown of the HAR file and how you can use it to diagnose the network side of your application, with +Ilya Grigorik and +Peter Lubbers.

Article: http://www.igvita.com/2012/08/28/web-performance-power-tool-http-archive-har/

Video: Make The Web Fast - The HAR Show: Capturing and Analyzing performance data with HTTP Archive format

Wait, DevTools could do THAT?

A fantastic presentation by +Ilya Grigorik on Chrome's DevTools

Video: Wait, Chrome Dev Tools could do THAT?

Notes: http://www.igvita.com/slides/2012/devtools-tips-and-tricks/#1

Progressive jpegs: a new best practice

Ann Robson explains how we can all reduce our apps' bandwidth consumption by making use of progressive jpegs

Article: http://calendar.perfplanet.com/2012/progressive-jpegs-a-new-best-practice/

Structural and Sampling (JavaScript) Profiling in Google Chrome

+John McCutchan and +Ilya Grigorik (he keeps showing up this guy!) cover Chrome's tracing tool. If you're a power user, this one is a must.

Video: Structural and Sampling (JavaScript) Profiling in Google Chrome!

Snow in canvas land

+Jake Archibald relives the horror of his 2-year-old code, and sets about fixing it

Article: http://calendar.perfplanet.com/2012/snow-in-canvas-land/

Improving Web App Performance With the Chrome DevTools Timeline and Profiles

A very thorough tutorial (with ANIMATED GIFS!) by +Addy Osmani on how to use Chrome DevTools to diagnose memory and performance issues.

Article: http://addyosmani.com/blog/performance-optimisation-with-timeline-profiles/

Scrolling Performance and Parallaxin'

Two articles by yours truly on understanding and improving scrolling performance in your applications

Article: http://www.html5rocks.com/en/tutorials/speed/parallax/

Article: http://www.html5rocks.com/en/tutorials/speed/scrolling/

Google I/O 2012 - Jank Busters: Building Performant Web Apps

+Nat Duca and +Tom Wiltzius of Google's Chrome GPU team cover a host of tips & tricks for maximizing your app's rendering performance

Video: Google I/O 2012 - Jank Busters: Building Performant Web Apps

Why moving elements with translate() is better than pos:abs top/left

+Paul Irish on using translates vs absolute positioning, and the performance implications of both

Article: http://paulirish.com/2012/why-moving-elements-with-translate-is-better-than-posabs-topleft/

IE8 uses IE7 DOM model on website

Probably it is a well known issue, and there should be many posts out there already mentioned that.  But in case you find this post, it means you are still having this problem.

IE8 will fall back to use IE7 DOM mode when sometimes visit a page, they called it "compatibility" mode.  However, if you doesn't need to support IE7, then it means it will screw you up, because the compatibility mode in IE8 is using IE7 DOM.

But the fix for it is very easy, just put that meta in your header

<meta content="IE=edge" http-equiv="X-UA-Compatible" />

And this will force IE to use the latest version of DOM mode in its browser engine. 

Find total number of lines recursively in terminal

Recently I need to do some analyze on code check into certain repository, and thanks to linux provide a very useful to for wc, you can get word count, number of lines types of information easily. And in order to do it recursively, here is the command you need, very handy for me :)

find . -name '*.js' | xargs wc -l

Web Platform Docs

If you guys didn't know, the W3C has started a project called Web Platform Docs ( currently in alpha release ) aimed at being the centralized resources for web developer.  This project has been and will continue be contributed by the main (and big) players in the web development industry.

http://docs.webplatform.org/wiki/Main_Page

If you haven't heard of that before, you can visit their "Getting Started" link,

http://docs.webplatform.org/wiki/WPD:Getting_Started

You don't need ssh-copy-id

This is what ssh-copy-id does

cat ~/.ssh/id_rsa.pub | ssh user@machine "mkdir ~/.ssh; cat >> ~/.ssh/authorized_keys"

If you are using Mac or other *nix flavor that doesn't have ssh-copy-id, the above is what you need.  That's exactly what ssh-copy-id does :)

Modeling and Reasoning behind DOM Events

A nice presentation on why DOM events behave in certain way.  So instead of telling you what a UI developer should know, it tells you why you have been told is true.

https://www.usenix.org/conference/webapps12/modeling-and-reasoning-about-dom-events

Here are some more good links in my reading list this month :)

Race Detection in UI
http://www.srl.inf.ethz.ch/papers/pldi12-wr.pdf

Whitepaper on Why Eval is Evil and General Misunderstanding
http://www.cs.purdue.edu/homes/gkrichar/papers/eval-ecoop-2011.pdf

Maintaining modular Javascript

Source coming from http://opensourcehacker.com/2012/06/29/maintaining-modular-javascript-codebase-with-requirejs/

RaspberryPi mouse and keyboard do not work after startx

Setting up my recently received RaspberryPi and everything seems fine, I can get the Pi working.  However, when I try to startx, my mouse and my keyboard doesn't response at all.  At first, I thought it might be the power drained is maxed out, but after several searches, looks like it is because my firmware is not updated.  However, updating Pi firmware is a pretty tedious task itself.  Let me documented my experience here and hopefully someone might be benefited from this post.

You need to download the rpi-update script

• wget https://raw.github.com/Hexxeh/rpi-update/master/rpi-update

Move the script to /usr/bin/rpi-update and run chmod +x /usr/bin/rpi-update

You need to do a update, since I'm using the Debian version, just run sudo apt-get update

Now you need to install ca-certificate

• sudo apt-get install ca-certificates

Install git-core

• sudo apt-get install git-core

Last, update your Pi firmware

• sudo rpi-update

Reboot your Pi, and login.  Now try startx and your mouse and keyboard should response again, enjoy your Pi!

Tools to test across all browsers

http://www.browserstack.com/
BrowserStack is a web based cross browser testing tool.  Has a nice feature to let you test on development server that might not be exposed to the public.

http://browsershots.org/
BrowsersShots let you enter your URL and do a browser compatibility test across the browsers you checked. Some people prefer Adobe Browser Lab because they claimed it's faster than Browsershots, and one can save his/her own set of browsers.

http://netrenderer.com/
IE NetRenderer allows you to check how a website is rendered by Internet Explorer 10, 9, 8, 7, 6 or 5.5, as seen from a high speed datacenter located in Germany. Just type in a URL in the field above and try it out - it's free!

https://browserlab.adobe.com/en-us/index.html
Adobe BrowserLab is an online service that helps ensure your web content displays as intended. Accurately preview web pages across multiple browsers and operating systems, navigate links, and use diagnostic tools to optimize websites efficiently.

https://addons.mozilla.org/en-US/firefox/addon/adobe-browserlab-for-firebug/
Adobe BrowsersLab for Firebug

http://spoon.net/browsers/
Browser Sandbox lets you "run popular web browsers with no installs" (IE6, 7, 8, 9+, Firefox, Chrome, Safari, Opera).

http://finalbuilds.com/iecollection.htm
Multiple IE versions you can installed.

http://www.microsoft.com/en-us/download/details.aspx?id=4580
For testing in different IE versions on Windows, you can also use Microsoft Virtual PC.

Note: The above is not an exhausted list of tools you can use for browser testing.  If you have more tools you have seen and want to share, please feel free to add it in the comments, thanks!

Reading List for June

My reading list for June :)

Twitter Engineering Blog
http://engineering.twitter.com/

Cross Browser Debugging
http://www.stubbornella.org/content/2012/05/02/cross-browser-debugging-css/#comments

Handling Multiple Ajax Call
http://lostechies.com/joshuaflanagan/2011/10/20/coordinating-multiple-ajax-requests-with-jquery-when/

Don't use Router handler in Backbone
http://lostechies.com/derickbailey/2011/08/28/dont-execute-a-backbone-js-route-handler-from-your-code/

Building Living Web Applications with HTML5 WebSockets

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HTML5 DevConf 12 Slides

HTML5 learning by building
https://docs.google.com/present/view?id=dnkhtrs_89d6qc8kf4

Building Faster Web
http://www.igvita.com/slides/2012/html5devconf/#1

CSS Shaders and Security
http://vhardy.github.com/presentations/html5-dev-conf-sf-2012/#/

Responsive Web Design
http://eddiemonge.com/rwd/

Realtime Web Application in the Wild
http://www.leggetter.co.uk/pres/html5devconf/pres/

HTML5 Accessibility slide

View more PowerPoint from Raj Lal