Media center upgrades

I have a small form factor (SFF) machine on the way to take up duties as a media center machine. After waiting for long, finally pulled the trigger on a Foxconn Barebones Book sized system and 4G of RAM. I haven't ordered a hard drive - the plan is to run XBMC completely off a USB drive. As it is, media is on a 1TB external disk and the cost of 2.5" laptop HDDs has gone through the roof.

In terms of software, I've got to figure out which XBMC to use - the contenders are to either install XBMCBuntu or go with one of the specialized builds from OpenElec. I'm still new to both - so will need to do some reading up before I decide.

OpenElec

OpenElec has small footprint (100MB), customized builds for different chipsets. Its meant to be run from a flash drive - so it has a few optimizations to make sure that it doesn't clobber your flash drive. Also, the stable version of OpenElec based on XBMC 10.0 "Dharma" has native AMD Fusion chipset support. Its also designed to be self updating and from reading the manuals, boots right into XBMC and OpenElec settings are all accessed via a XBMC extension so you never have to drop down to the linux machine underneath it.

At this point, looks like OpenELec is really limiting. I would really love to run a browser, use the machine for torrenting etc - and somehow using the XBMC interface for all those doesn't sound too good.

Also, XBMC Eden is supposed to support AMD Fusion natively and OpenElec hasn't been updated yet for Eden (there are nightly builds available though that are based on Eden).

XBMCBuntu

XBMCBuntu is XBMC's official liveCD - you can use the live CD to install to another USB drive media and provided the system can boot from USB, you're off to the races.
The thing here is that it isnt specific to a 'flash' drive - so there's a small tradeoff in terms of the flash drive life. XBMCBuntu is based on Lubuntu 11.10.

Migrating the database

I also have to figure out how to migrate my XBMC database of movie information from Windows XP to the Linux setup - not sure if its even possible - but its something that's definitely worth a shot. In any case, if it doesnt work, then will just let XBMC rebuild its database overnight.

The hardware's supposed to come in april 2nd week - can't wait for it :)

Moved to bitbucket

I've been using Git Enterprise for hosting private repositories since github's free plan doesn't include any private repos. Git enterprise's worked - but the UI leads a lot to be desired the few times that you actually have to use the web interface.

So the other day while doing something else, I landed on bitbucket . Bitbucket is Atlassian's code hosting service - and for some reason I was under the impression that it only supported mercurial repositories. Was pleasantly surprised to see that not only can you have git repos, you also get unlimiited private and public repos with upto 5 collaborators all for the unbeatable price of free!

Can't ask for more - so it's Bye-bye Git Enterprise! and Hello! Bitbucket... Bitbucket also has a nice helpful repo import - plug in the url to your git repo and it gets cloned. Once that was done, it was a simple matter to update the origin url of my repo with

git remote set-url origin https://raghur@bitbucket.org/raghur/home.git

Hey look! A flying pig!

:)

MS has added git support to Codeplex - who'd have thought that such a day would ever dawn.

Kudos to the good souls at MS who made this happen - One can only imagine the kind of conversations that would've taken place to get the necessary approvals for this :).

Still Git has great mindshare but native windows support is pretty bad. Hopefully this might even help making a good gui for git on windows. After creating an abomination like TFS, MS should realize the benefit of just going with openly available tools rather than create.

Maybe not - that's more like seeing a squadron of pigs flying!

Coffeescript looks promising

I've just ran across Coffeescript... can't believe what sort of a hole I've been living in.

It's a source to source compiler (ie when you 'compile' a coffeescript script, you get javascript source.)

So why would you want a source to source compiler for Javascript?
Well, as apps become more and more 'front-end' heavy with DHTML/Ajax bling bling, the javascript that holds all that together also becomes more and more complex. Yeah, sure you used Jquery (or 'insert your favourite js framework') - but that's not even scratching the surface. You're still writing tons of js code, and dealing with its idiosyncracies and tearing your hair apart.

Enter Coffeescript - clean syntax with elements of style borrowed from ruby and python, this is super clean and efficient. You write your code in coffeescript which is neat, clean and concise. What it generates is very idiomatic and clean javascript.

Let's try something - take a guess at what the following does:

    var Animal, Mammal, animal, farm, _i, _len,
      __hasProp = {}.hasOwnProperty,
      __extends = function(child, parent) { for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; };

    Animal = (function() {

      function Animal(name) {
        this.name = name;
      }

      Animal.prototype.speak = function() {
        return console.log("I am a " + this.name);
      };

      return Animal;

    })();

    Mammal = (function(_super) {

      __extends(Mammal, _super);

      function Mammal() {
        return Mammal.__super__.constructor.apply(this, arguments);
      }

      Mammal.prototype.speak = function() {
        Mammal.__super__.speak.apply(this, arguments);
        return console.log("and I'm a mammal");
      };

      return Mammal;

    })(Animal);

    farm = [new Animal("fish"), new Mammal("dog")];

    for (_i = 0, _len = farm.length; _i < _len; _i++) {
      animal = farm[_i];
      animal.speak();
    }
    

And now - see if you like this better:

    class Animal
        constructor: (@name)->
        speak: ->
            console.log "I am a #{@name}"
    
    class Mammal extends Animal
        speak:->
            super
            console.log ("and I'm a mammal")
    
    farm=[ (new Animal "fish"), (new Mammal "dog")]
    
    animal.speak() for animal in farm

The javascript version is the generated from the coffeescript version above . Head over to coffeescript.org page - they have an online interpreter where you can try out coffeescript code and it generates equivalent javascript source.


If you're wow'ed with that (I am) - and just in case you're saying good bye to javascript, here's the nub.. since its a source to source compiler, unless you understand what's going on under the covers, you'll hit a problem soonish when you have to debug something.

So, Javascript isn't optional - but if you have that bit covered, there's no reason to have to 'live' with the iffy side of javascript. Take a look something like coffeescript and have a little fun along the way.

VIM config updates

Ultisnips has been updated to 2.0. See the video here for the updates and new features. One piece of information - and one that I was eagerly waiting for is that 2.0 works perfectly with auto complete popup. This wasn't always the case - in fact, the bug on launchpad for the same had been marked as a 'wont-fix'. In any case, I was super thrilled to see that its been fixed.

Zencoding.vim also has been updated... if you're writing any sort of markup the old way, then just google zencoding - there's a couple of videos that will blow your socks off. For the truly impatient, you write a CSS like expression and its converted back to markup! How cool is that?

IOS-no previous simulator versions!

Ran into a situation today where we had a mobile web app that was reported to be misbehaving on iOS 3.2. The Mac at work has the latest XCode and IOS 5 simulator loaded on it. So we thought it would be quite routine to just start a simulator running IOS 3.2 - after all this having simulators of different versions of the OS is pretty routine. Android makes it trivial and before that, Blackberry has always had different simulator versions for different versions of their OS. Truth be told, RIM probably overdid it. They had too many versions, a developer website that would drive even the most persistent BB fanboys to stark raving madness and documentation that took great pains to suck! Hell, its a separate rant altogether :).

Anyway, after clicking around Xcode for a bit, imagine our surprise when we found that only a device debugging package for iOS 3.2 was available as an updated package for Xcode. That didnt seem right - so off to Google and there's a post on SE http://apple.stackexchange.com/questions/14128/how-do-i-install-the-3-0-iphone-simulator-on-xcode-4

Apparently, Apple doesn't want you to test on previous versions (or atleast - 2 major versions before. Testing on last major version IOS4 is ok though). Now isn't that absolutely ridiculous? Sure, Apple wants people to upgrade their phones to the latest OS versions and they've done a great job of ensuring that later versions of the OS work on older generation phones - but from a development tool standpoint, making tools to test your app unavailable is taking things too far. So tomorrow if my site/app doesnt work properly on a iOS 3 device, the user isnt going to blame Apple. Its the app developer who gets the bug report :(.

So once I'd made my peace with Apple's decisions and diktats on what simulators I was allowed to play with, I reflected on it a bit. I think the key is that that IOS's simulator is really just a simulator (ie software running on the host machine but mimicking a device). On the other hand, the Android emulator is actually a full qnx VM that's totally isolated from the host machine. In IOS's case, the simulator is sharing libraries and tools installed on the base OS - and as such, it would be quite hard to simulate older versions. In Android's case, since each emulator is really like running a VM, you can have all the different versions at your beck and call. On the flip side of things, the emulator approach really slows things down - everything from booting up the VM to actually running code inside it whereas IOS simulator positively zips around. I'm not sure if this is indeed the case - it's just my theory. Looking around on the net, I couldnt find a solid reference - so if you know of one, drop it in the comments.. I did find a few on SE/SO - but they were by no means conclusive http://stackoverflow.com/questions/4544588/difference-between-iphone-simulator-and-android-emulator

VIM macro super powers

So my affair with Vim continues - and I seem to have discovered VIM's macro super powers. The obvious next step is to shout from the rooftops and hence this blog post (and there's hardly anything original - apart from the fact that I've just had a 'aha' moment when it comes to macros and thought it might help other budding vimmers out there...

A little primer - Macros let you repeat a set of commands. The way to go about it is to press q<macro_letter> where <macro_letter> is between lowercase a-z. This starts recording a macro in Vim (and you see a recording message at the bottom). Now hit commands you want to repeat later and press q when done to finish recording. VIM records all the keystrokes you enter in the register you specified as the macro name. To now execute the macro, position the macro on the line and then hit @<macro_letter> and Vim will faithfully replay your commands.

Its a great time saver - especially for complex editing tasks where search/replace doesn't cut it. But, if you're feeling a dissappointed after coming this far (after all, I promised a aha moment), then hang on.

Today's discovery was that you can edit macros that you've recorded quite easily and save them back!!! THIS IS HUGE. Why so? Because when you record a macro, its quite normal to jump around quite a bit or get one or two keystrokes wrong. In fact, its for this reason that I could never use Emacs's macro facility and failed to just 'get it'. However, in VIM, you could just open a scratch pad editor and hit "<macro_letter>p - that's double quote-letter-p to paste the contents of register containing your macro. You see your macro keystrokes - so go ahead and edit them and then use "<register>y<movement> to save your edits back to the register. You can now execute the macro with a @<macro_letter> as if that's the way it was recorded in the first place.

Another obvious tip - you can execute the contents of any register as if it were a macro with a @. Not sure when that could be helpful - but knowing that its possible is good.

Yoohooo!! Successfully compiled Android from source

Finally!!!

So my last weekend project had been to compile Android ICS from source. Given that the size of the repo itself is in excess of 6Gigs, just getting it down itself took the better part of Friday night and Saturday night. When I got down to running make on it, it was Sunday afternoon.

Needless to say, things didn't work too well. I'm running this on a 32 bit Ubuntu 10.04 Virtualbox with a piddly 1GB RAM. When make failed the first time, realized that swap was a measly 300Mb. First steps first, went on to increase memory to 2GB (that's all I can spare) and increased swap to 2Gs.

Compilation next round started and that failed too - ran out of disk space - and this was Sunday night. Things kind of stayed there and finally this evening, resized the disk in virtualbox to 50Gigs. Again started the compilation and this time ran into linker errors when building webcore. One more round of troubleshooting involved deleting the previously built static library and then running make again. Surprisingly, this time make completed successfully - to the point where I wasn't sure if it had succeeded or just failed silently on something else.

The next step was to run the emulator to see if it really would boot up. Over at source.android.com, they oversimplify it when they say that you just run emulator from the android root folder. That didn't work for me - and this time it was because I hadn't sourced the envSetup.sh file... this thread http://groups.google.com/group/android-platform/browse_thread/thread/91ff18e034acf951 helped in tracking that one down.

So finally, after all that trouble, I have my very own ICS build running!!!!

For now, its onward ahoy to setting up Eclipse and starting with a fix I've been mulling about for sometime now..

Signing off from cloud nine
R

Ubuntu, Console VIM - weird characters in insert mode

Now that I feel quite comfy with VIM, over the weekend I needed to edit a config file in my Ubuntu 10.10 Virtualbox machine quickly. Instead of GVim, I just opened the file in console VIM. As I hit i to get into insert mode, a bunch of weird character boxes were inserted. That was not good at all :( - just when you think you're comfortable with something if it does something totally weird. In any case, I was in too much of a hurry to bother and went about editing my file with gVim. Also, backspace was wonky (same weird characters) - so I felt better. For some reason that I fail to understand, why must Linux make proper backspace and delete handling such a pain! In any case, it's something that I've dealt with enough times to know that there'll be something on Google.

Later on, tried to see what all the fuss was about. Googling around, I found :help :fixdel and that seemed simple enough. Alas, when I tried it out, it didn't fix the issue at all. Also, I seemed to be getting weird characters just pressing i to get into insert mode - and the VIM wiki page didn't have anything about that. Neither did Google turn up anything that seemed related.

So today early morning, on a whim, read up a little on VIm terminal handling. I have the following in my .vimrc
[sourcecode language="text"]
set t_Co=256
[/sourcecode]
Maybe it was the color escape code that was coming in - so checked out :echoe &term which returned xterm under gnome-console and builtin_gui under gvim. So I've put the following bit in my .vimrc and it seems to have fixed things nicely:
[sourcecode language="text"]
if &term == "xterm"
set term=xterm-256color
endif
[/sourcecode]

Android Annoyances

So yesterday and today while driving back from work, I've had to join conference calls. The conference call provider we use at work has 10 digit passcode numbers. Usually, I have a few bridge numbers with the DTMF codes saved in my contacts so I can just click on the contact to get dialled to the access number and have the participant passcode typed in for me. However, yesterday and today's calls were on a different bridge and I had to try to remember a 10 digit number after dialling the access code - and all that while driving. Needless to say, it took a few attempts and I'm sure at that time my attention wasn't where it should have been - ie on the road and on the traffic. Besides being thoroughly unsafe on Bangalore roads, its just frustrating(thankfully - better sense prevailed today and I pulled over, dialled into the bridge and then started driving again).

So the issue really is that the native parser that parses out email and calendar invites doesn't understand access codes and passcodes. It shouldn't be too hard to do - but then I started digging a bit deeper this evening. Granted that the parser isn't smart enough, at the very minimum if it handles tel: links properly, then its just a matter of educating folks who set up meetings to set them up so that you can click to call with something like <a href="tel:23423432233,,9230233#"> - in fact, in Outlook if you type TEL: and then the number, it will automatically be parsed as a tel: hyperlink. Turns out that its a massive fail - if I click the link, Android will show me the dialler but without the DTMF codes (basically, only the number upto the first comma). TOTAL FAIL.

So, Isn't this something that should have been brain dead simple to do? I mean - this is 2012 after all - and I'm not asking much. All I'm asking is that the tel: url parsing/handling be done in such a way that we can use our phones properly!!! Turns out that there's an open ticket 4575 since Nov 09. And its marked as an enhancement - I find that laughable since its a bug and definitely something that can be done quite easily (esp since a contact that has DTMF codes is dialled properly). However, for the 2 years that the ticket has languished, there have been 73 comments and not a single response from big GOOG :(

At the moment, doesnt look like this is going to be fixed - so I started browsing thru the Android source tree to see if I can find where the implementation for tel: urls - however, given the size of the android source, that's like trying to find a needle in a haystack. Guess I'll have better luck with seeing if CyanogenMod folks can fix this in CM9.

So about that, the other thing that has confounded me is why in the world can't Android bundle a decent T9 dialer/smart dialer out of the box. I know there are tons of apps on the market that do that - but seriously, is smart dialing something so out of the world that I need an app for it? As expected, there's a ticket but no action.

I think its safe to assume that Google isn't interested in fixing these issues as there's no 'benefit' in doing so - though for the life of me, I can't imagine either of them being particularly hard. In any case, I'm eagerly awaiting a CM9 build for the Nexus One (right now, am running an ICS build from XDA).

Facebook publicize is driving me nuts!

I'm thoroughly frustrated with Wordpress.com's facebook publicize feature. In theory, its supposed to post to your facebook wall whenever you publish a new post and that way publicize your post among your friend circle.....if it ever works. I've done all the resets, disconnects and reconnects and it just doesn't. Now, this could very well be a facebook problem rather than a wordpress.com problem - so while my rant might be misdirected, its a rant anyway against the thoroughly frustrating experience. Its like a bucket of cold water on my enthusiasm to be more active on my blog.

You see, with having posted rarely to this blog, I get a measly 70/80 page views per day (yeah - there's no need for the snide looks); So one part of actively persisting on the blog has been to see if I can get to 100+ page views per day. Modest goals, I admit - and getting the linky to a new post on the FB wall is a big part of it. If only it worked as it says on the tin :( :(

Anyway, this post is a test in itself - I've just jumped through the said hoops , mumbled the magic incantations and in other words, followed every bit of direction available to make this work right. And if this post shows up on my FB wall, well and good. If not, then I'm done with trying to get this to work.

A syntax highlighter extension for Deck.js

So for the past few hours, have been playing with Deck.js . I like the idea of a web based presentation format rather than a blob like powerpoint. At the same time, I'm a bit circumspect too - given the state of the tools. At least for my use, there's really no burning need that powerpoint can't solve (though I get the shivers everytime I have to do a presentation). All the web based/HTML5 seem raw at the moment on some much needed features (slide notes, slide prints, scaling issues etc).

Anyway, after a few minutes on Google and StackOverflow, decided to give Deck.js a spin. Deck.js is really nice and you should take a tour if you haven't done so. So finally, after giving the online presentation and the introduction a try, downloaded the latest to give it a more thorough spin. As usual, one of the first things was embedding code snippets and I thought it would be nice to integrate Alex Gorbatchev's SyntaxHighlighter into this. Turned out really simple to do (I'm sure there are other syntax highlighter extensions to deck.js out there) - but since I got something working pretty easily, here it is:

Create a file called deck.syntaxhighlighter.js with code below:

[sourcecode language="javascript"]
(function ($) {
$("head").append(
'<link href="http://alexgorbatchev.com/pub/sh/current/styles/shCore.css" rel="stylesheet" type="text/css" />'
).append(
'<link href="http://alexgorbatchev.com/pub/sh/current/styles/shThemeDefault.css" rel="stylesheet" type="text/css" />'
);
function setupSyntaxHighlighterAutoloads() {
console.log("calling SyntaxHighlighter");
SyntaxHighlighter.autoloader(
'applescript http://alexgorbatchev.com/pub/sh/current/scripts/shBrushAppleScript.js',
'actionscript3 as3 http://alexgorbatchev.com/pub/sh/current/scripts/shBrushAS3.js',
'bash shell http://alexgorbatchev.com/pub/sh/current/scripts/shBrushBash.js',
'coldfusion cf http://alexgorbatchev.com/pub/sh/current/scripts/shBrushColdFusion.js',
'cpp c http://alexgorbatchev.com/pub/sh/current/scripts/shBrushCpp.js',
'c# c-sharp csharp http://alexgorbatchev.com/pub/sh/current/scripts/shBrushCSharp.js',
'css http://alexgorbatchev.com/pub/sh/current/scripts/shBrushCss.js',
'delphi pascal http://alexgorbatchev.com/pub/sh/current/scripts/shBrushDelphi.js',
'diff patch pas http://alexgorbatchev.com/pub/sh/current/scripts/shBrushDiff.js',
'erl erlang http://alexgorbatchev.com/pub/sh/current/scripts/shBrushErlang.js',
'groovy http://alexgorbatchev.com/pub/sh/current/scripts/shBrushGroovy.js',
'java http://alexgorbatchev.com/pub/sh/current/scripts/shBrushJava.js',
'jfx javafx http://alexgorbatchev.com/pub/sh/current/scripts/shBrushJavaFX.js',
'js jscript javascript http://alexgorbatchev.com/pub/sh/current/scripts/shBrushJScript.js',
'perl pl http://alexgorbatchev.com/pub/sh/current/scripts/shBrushPerl.js',
'php http://alexgorbatchev.com/pub/sh/current/scripts/shBrushPhp.js',
'text plain http://alexgorbatchev.com/pub/sh/current/scripts/shBrushPlain.js',
'py python http://alexgorbatchev.com/pub/sh/current/scripts/shBrushPython.js',
'ruby rails ror rb http://alexgorbatchev.com/pub/sh/current/scripts/shBrushRuby.js',
'sass scss http://alexgorbatchev.com/pub/sh/current/scripts/shBrushSass.js',
'scala http://alexgorbatchev.com/pub/sh/current/scripts/shBrushScala.js',
'sql http://alexgorbatchev.com/pub/sh/current/scripts/shBrushSql.js',
'vb vbnet http://alexgorbatchev.com/pub/sh/current/scripts/shBrushVb.js',
'xml xhtml xslt html http://alexgorbatchev.com/pub/sh/current/scripts/shBrushXml.js'
);
SyntaxHighlighter.all();
}
$.getScript("http://alexgorbatchev.com/pub/sh/current/scripts/shCore.js",
function () {
$.getScript("http://alexgorbatchev.com/pub/sh/current/scripts/shAutoloader.js",setupSyntaxHighlighterAutoloads);
});
})(jQuery);
[/sourcecode]

Throw that in your deck.js/extensions folder. IN the slide deck you want to use this extension, include a script line before the end of the body tag:

[sourcecode language="html"]
<script src="../extensions/deck.syntaxhighlighter.js"></script>
</body>
</html>
[/sourcecode]

And you're done. Now to include any code snippets in your deck, just use either of the methods specified in the SyntaxHighlighter page (snippet for the script tag below)

[sourcecode language="html"]
<script type="syntaxhighlighter" class="brush: js">
$(document).ready(function () {
//this is the function body
});
</script>
[/sourcecode]

That's all there is to it. Code above can do with some improvements (conditionally load local copies if the remote loading fails etc) - but this is just a quickie script - so feel free to modify this to your heart's content.

Vim - unmap Esc!!

So I had the bright idea (by no means original, though, as I later figured out) that it'd be great to avoid the Esc key on Vim as its so far away from the home row. The alternative to pressing Esc is Ctrl-[ which, even though I've mapped CapsLock to control, I still find hard. So then, after some more googling around I've settled down on mapping jk to Esc. Its been a few hours with this setup and while its been an absolute pain till now, I think its a great way to avoid the Esc key jump. I can already feel my finger muscle memory relearning and my hand jumps instinctively for the Esc key much less now.

Here's my setup in case you want to try this out. Bung the following into your .vimrc or _vimrc as the case may be:

inoremap  :echoe "use jk"
inoremap jk 

The first mapping makes VIM echo a reminder. Its not friendly since it introduces a pause. However, the idea is to make the Esc so painful that you will shy away from hitting it.

Upgraded to XBMC 11.0 Eden beta

So I upgraded the good ole' media center machine at home to XBMC 11.0 Beta
. XBMC has been one of those software finds that has been just marvellous - to the point where I can't imagine the telly at home without XBMC. I've pretty much stopped watching regular tv/cable and almost exclusively on XBMC.
Also, its been a great way to keep the aging laptop (circa 2006 - core2Duo 1.6 Ghz, 2 Gb RAM and a piddling ATI Radeon X1600) in active duty.
Here's a hat-tip to all the XBMC guys and gals. And if you're not running a media center at home, you should give it a spin - XBMC makes your idiot box smart!

Unit testing Apache CXF RESTful services - code available

So, the original post on the topic written about two and a half years ago had code snippets, but there's been comments and PMs for the complete code. So last week, as I resurrected this blog, decided to get that code out on github. Unfortunately, that was easier said than done; it has been quite some time and frankly, I'd lost the code. I must've switched machines about 3 times in the interim and gone from SVN to github for personal projects. Some hunting around ensued and thankfully, I was able to find the actual code we wrote based on the sample I'd posted. So cleaned that up - and just extracted the unit testing example out of it and pushed it to github - get it here. I haven't updated any of the dependencies - so this is still running against spring 2.5 and cxf 2.2.3 (I think) and things might've changed quite a bit since then (I haven't used the JAXRS bits of CXF much after that)

Running tests:
[sourcecode language="bash"]
mvn test
[/sourcecode]
Running the server:
[sourcecode language="bash"]
mvn jetty:run
[/sourcecode]

Syntax highlighting support in Wordpress.com with markdown

Now that I've cozied up to Vim/VimRepress combo for posting to this blog, there are a few things where I'm finding issues with posting code. With straight wordpress.com, I used to be able to mark up code with the [sourcecode][/sourcecode] tag and syntax highlighting comes in. With markdown - indenting a block of code with 4 spaces renders it as a <pre><code></code></pre> tags, but I don't know if there's a way to let WP.com know what language it is or any way to use the [sourcecode][/sourcecode] plugin from markdown.

Some googling on the topic didn't result in any wp.com specific answers (some folks have posted on using other plugins et cetera with a self hosted Wordpress - but nothing for wordpress.com)

Any ideas/pointers? Guess I should also post the question on the Unix stackexchange

Update on 1/1/2012

Using the sourcecode language="xxx" tag works - but you cant have any empty lines in your source.

Creating an interstitial login page with JqueryMobile

So, at work, we're building a mobile website using JqueryMobile. The app has a bunch of publicly visible pages however, other pages require the user to be authenticated. We didn't want the user to be forced to login on the first page. Instead, whenever a protected page is accessed, and if the user insn't logged into the app, we'd like to take him to the login page. Once he's successfully authenticated, then take him to the page he was navigating to. Doing this in a normal webapp is quite standard - however, with JqueryMobile, query params meddle with the hash navigation model. Also, the page that the user tries to access could be a div in the same physical page or a different url that needs to be fetched.

Trying to solve this was interesting as we were all really just getting started with JqueryMobile - so finding the ideal solution required a few tries. The solution takes a leaf out of JqueryMobile's approach. The outline of the solution is:

1. Any page div that's a protected resource is marked with a data-needs-auth="true" attribute


2. We hook into the document level pagebeforechange event to see if the user is trying to transition to a page requiring authentication. If so, then check if we have the user's authenticated context available.


3. if the said context isnt available,
   
   
   1. Cancel default event handling since we're now going to navigate the user to the login page.
   
   
   2. save the toPage object - so once the user is logged in, we know where to take him.
   
   
   3. navigate to the login page.
   
   
   
   


4. In the login page, the page can call the server apis to autheticate the user. Once the user is authenticated, then
   
   
   1. See if there's a valid returnTo object, if so, take the user to the page.
   
   
   2. If not, take the user to a 'default' page - in our case, this is the app dashboard page.
   
   
   
   

Code below
[sourcecode language="javascript"]
var pageVars = {}
$(document).bind("pagebeforechange", function (event, data) {
if (typeof data.toPage == 'object' &amp;&amp; data.toPage.attr('data-needs-auth') == 'true') {
if (!sessionStorage.getItem("TokenSSKey")) {
if (!localStorage.getItem("TokenLSKey")) {
pageVars.returnAfterLogin = data;
event.preventDefault();
$.mobile.changePage("#Login_Page", { changeHash: false });
}
else {
sessionStorage.setItem('TokenSSKey', localStorage.getItem("TokenLSKey"));
}
}
}
});
[/sourcecode]
The login event handler that handles the server response that's received once we pass the username and password

[sourcecode language="javascript"]
function SuccessLogin(data) {
if (data != null &amp;&amp; data.LoginResult != null) {
if (data.LoginResult.Code === 0) {
localStorage.setItem('UNameLSKey', data.LoginResult.User.AccountName);
if ($("#RememberMeChkBx").is(":checked")) {
ErrorPanel.html("");
localStorage.setItem('TokenLSKey', data.LoginResult.Token);
sessionStorage.setItem('TokenSSKey', data.LoginResult.Token);
}
else {
ErrorPanel.html("");
sessionStorage.setItem('TokenSSKey', data.LoginResult.Token);
}
if (pageVars &amp;&amp; pageVars.returnAfterLogin) {
$.mobile.changePage(pageVars.returnAfterLogin.toPage);
}
else {
$.mobile.changePage("#DashBoard_Page", { changeHash: false });
}
}
}
}
[/sourcecode]

Learning Vim

Is it worth it?

Definitely seems to be. I've looked at VIM in the past, tried it out too a couple of times or more, failed miserably(mostly within a day or two) and then wondered Why nutheads use VI. This would usually be followed with going back to the comfort of Emacs. I think over the years, I've spent more time customizing Emacs than actually getting any work done with it. And somewhere that felt wrong. In light of that, the minimalistic VIM looked attractive and worth another try.

So what was different about this time?

So this time things worked out a bit better. Rather than firing up VIM, spent some time reading through other's experiences on picking up VIM. And the first thing I did right was to disable the arrow keys in normal mode (I still have them in insert mode)

    " disable arrow keys
    noremap   <Up>     <NOP>
    noremap   <Down>   <NOP>
    noremap   <Left>   <NOP>
    noremap   <Right>  <NOP>

Once you have that bit, you're forced to use h/j/k/l. And while h/j/k/l muscle memory is built up within a week, the nice thingthat really happens is that you dont use h/j/k/l much - instead you move to using more efficient movement commands. There're aton of resources/cheatsheets on the web - but the approach I followed was to figure out some small keystroke when I needed it.What that mean't was that I could get work done - but at the same time get more efficient gradually.

Customizations

VIM out of the box is pretty badly configured - and that's part of the reason that people seem to shy away from it. In fact, all the times that I tried out VIM before, I didnt even come close to cusotimizing my .vim. There are folks who have curated vim dotfiles on github etc - but my advice is to stay away from them. You should know what goes in your .vim and be in control of thatrather than getting a bunch of things in your .vim that you dont understand. Just so you know, looking at the github history for my vimfiles repo - the initial commit was 3 months ago - but after that, all the commits have come in only in the last 4 weeks.What that means is that while I put in a vim file initially, I didnt do much with it initially since I was just getting a hang of the basics. Once one becomes comfortable with the basics, one moves to customizing the vim environment more and more.

Parting words

To summarize, VIM definitely seems nice once you invest into it. It's easy to drop off in the initial stage and not go any further - and I believe this is what happens to the vast majority of folks who try it out. However, once you build that initial comfort level,it feels light, fast and easy.Start easy, persist, and customize bit by bit - you'll feel yourself going from struggling with Vim to feeling comfortableand then to customizing your environment for an even better experience with VIM.I've definitely been more productive with VIM than I ever felt I was with Emacs - and these posts to my blog from Vim part of that.Besides that, I've used VIM effectively with a decent sized js code, html markup etc and felt the speed of editing inspite of still beinga noob in Vim terms.

A new look

Changed the theme of this blog and moved around the widgets a bit.
Finally, I can bear looking at this blog :) - hope that holds good for you too.

Compiling VIM

Running ubuntu 10.10 here and ubuntu repos have only vim 7.2. I'm sure there's a ppa out there that has 7.3, but thought
that compiling vim from source would be a good exercise - plus I get to compile it with the options that I'd like
rather than relying on someone's build.

Here's the options that I enabled:
[sourcecode language="text"]
CONF_OPT_PERL = --enable-perlinterp=dynamic
CONF_OPT_PYTHON = --enable-pythoninterp
CONF_OPT_RUBY = --enable-rubyinterp
CONF_OPT_GUI = --enable-gui=gtk2
CONF_OPT_FEAT = --with-features=huge
BINDIR = /usr/bin
DATADIR = /usr/share
[/sourcecode]
Here's hte other dependencies I had to install
[sourcecode language="bash"]
sudo apt-get install libperl-dev ruby-dev python-dev libgtk2.0-dev
[/sourcecode]
Once you have the deps installed, just run
[sourcecode language="bash"]
make
sudo checkinstall
[/sourcecode]