JS Console

JS Console is a tool I enjoy for messing around with JavaScript without having to create a bunch of HTML (although you can work with the DOM in JS Console). This is proving very handy as I go through JavaScript books/tutorials and want to try code out quickly.  JS Console allows you to do remote JavaScript debugging as well.

How do I use JS Console?

Type or paste JavaScript into the text bar at the top.  You can also load JavaScript libraries (like JQuery) or DOM.

JS Console remote debugging

I don't do mobile development, but it looks like there's a neat way to use your computer's browser to debug JavaScript on your phone(!) or on another machine/session.  And there's a native iOS app.  I have not experimented with the remote debugging.

What can I access in JS Console?

DOM

Looks like you can get to everything in your browser.  If you type document in the text field, for example, you'll get the HTMLDocument object represented as a String.  

localStorage and sessionStorage

You can also view and manipulate localStorage and sessionStorage if supported by your browser (when I did this in IE7 I got undefined as these aren't supported until IE8).  

I added items to localStorage and remoteStorage, opened another Chrome window and verified that in Chrome and  Firefox separate tabs represent new sessions.  I also learned that JS Console uses sessionStorage to store your history.  And I saw that localStorage is browser-specific.  All Chrome windows and tabs saw what I'd added to localStorage in Chrome even after closing and reopening browsers.  Same thing with Firefox, but Chrome didn't see Firefox's localStorage and vice versa.

JavaScript

I've been looking at JavaScript a bit over the past six months.  

Books
The most helpful titles I've read are:
Eloquent JavaScript
Intro to programming using JavaScript as the vehicle.  Covers programming fundamentals quite a bit.

JavaScript: The Good Parts
Less of a beginning programming guide and

Learning JavaScript (currently reading now)
Intro to JavaScript that assumes an understanding of programming fundamentals.

Tools
QUnit is what I've used to unit test my JavaScript (even if I'm not using JQuery's features in my JavaScript).  I find that unit tests are a great tool for helping me figure out how a language/framework works since they let me submit different scenarios easily, as well as helping me persist the questions I've asked and answered about a language/framework.
QUnit gave me some trouble around the setup, but it was worth the effort, especially once I got into writing more complex functions.

JSConsole is a tremendous tool that I just discovered (today!).  Those of you familiar with consoles for Ruby, Groovy, IO, etc. understand how helpful they can be for quickly answering implementation questions. For example, I wanted to know what would happen if I executed slice(-10) on an array with three members.  Instead of having to build the HTML, the JavaScript, connect the two and figure out how to view the results (alert, innerHTML, etc.) I used the console and it took me about a minute to create the array and try a bunch of slice overrides.

W3Schools Tryit Editor for JavaScript is a helpful tool if you want an easy way to experiment with DOM modification in JavaSript.  On the left side you have HTML and embedded JavaScript -- on the right side you have the output.  You can also use this to experiment with embedded CSS.

Browser debuggers/consoles are handy for debugging (using breakpoints) or monitoring DOM manipulation.  F12 on a PC keyboard (Windows or Ubuntu) will toggle the console for Chrome and Firefox (if you have Firebug installed for the latter).

dd-wrt for Linksys WRT54G v8

http://dd-wrt.com/wiki/index.php/Linksys_WRT54G_v8.0_%26_v8.2

My sister's WRTG54 v8 with stock firmware started hanging when distributing IPs so I decided to put dd-wrt on it.  I had done the same with my WRTG54 v1.1 with no problems so I assumed it would be a snap.  I was going to use it for a client bridge (see Andy Frank's post).

Ubuntu needed for tftp
Using tftp to upload dd-wrt.v24_micro_generic.bin didn't work from my Windows XP box, so I gave it a shot from an Ubuntu 12.x box and that worked.

Brick
Then I got myself into a jam since the primary subnet was non-standard.  I tried to change the secondary router (the one I just flashed), but couldn't connect to the web interface at all.  I did the 30-30-30 reset a few times and thought I bricked it.  The Power and WLAN lights no longer glowed, but the light corresponding to the port connected to my computer glowed.  I did the 30-30-30 reset a few times with no luck.

Wait, then unbrick
Then I let the whole thing sit overnight.  Next evening I was able to connect to to the dd-wrt web interface, and then found that it was serving IPs just fine.  

Whew...

Create client bridge
I gave the now-working WRTG54 v8 back to my sister.  I still didn't have what I was looking for: a client bridge for my ancient Pentium IV running CentOS.  I want the box close to me instead of close to the router behind the TV where it gets hot and is hard to reach.

I ran into issues with a primary (Belkin) broadcasting in N and a secondary (Linksys) only capable of B and G.  Also, the primary has different WPA2 options than the secondary.  And the secondary wouldn't let me select a channel in client bridge mode.  This whole thing is probably easier with two identical routers both running dd-wrt.

Success with compromises
Setting the primary to B and G mode, changing channel selection from Auto to a fixed value and moving from WPA-PSK+WPA2-PSK/TKIP+AES to WPA2-PSK/AES did the trick.  Plugged in Ubuntu laptop connected to the internet when I disconnected from the wired connection I'd set up per the dd-wrt instructions and connected using the Auto Ethernet option.

Back out compromises
Then I began backing out the changes I'd made to the primary.  Moving back to B, G and N worked fine.  Setting channel selection back to Auto didn't affect the secondary's ability to connect to the internet either.  Reverted primary to WPA-PSK+WPA2-PSK/TKIP+AES and still was able to connect to the internet through the secondary.  Seems like this is kind of what  Andy Frank did, but he may have found it possible to go back to WPA2 on the secondary.

cygwin windows processes and ps: the W option

http://cygwin.com/cygwin-ug-net/using-utils.html


Hard to believe I haven't been bothered by this before: if one runs ps in cygwin Windows processes are not displayed unless the W option is used.



$ ps -ef | grep post*

-- nothing

$ ps -efW | grep post*
       0    3220       0 ?          Jun 17 D:\PostgreSQL\9.1\bin\postgres.exe
       0    5684       0 ?          Jun 17 D:\PostgreSQL\9.1\bin\postgres.exe
       0    3808       0 ?          Jun 17 D:\PostgreSQL\9.1\bin\postgres.exe
       0    3072       0 ?          Jun 17 D:\PostgreSQL\9.1\bin\postgres.exe
       0    3620       0 ?          Jun 17 D:\PostgreSQL\9.1\bin\postgres.exe
       0     412       0 ?          Jun 17 D:\PostgreSQL\9.1\bin\postgres.exe

Unfortunately I've not found a cygwin way to kill the Windows processes.  I'm stuck with the Windows way:

$ kill -9 1600
-bash: kill: (1600) - No such process



$ taskkill /F /PID  1600

SUCCESS: The process with PID 1600 has been terminated.

Create Ruby on Rails development environment for Windows XP: DOS prompt and pik

This post details a Windows setup for the book Rails 3 in Action.  Having done both an Ubuntu 12.04 and a Windows XP RoR setup, I strongly recommend the former: much quicker and easier.


I was having some issues with my Cygwin/RVM install so I decided to try using the DOS command prompt and pik instead.



http://stackoverflow.com/questions/9189628/install-ruby-on-rails-on-windows
I think the answerer to this post incorrectly uses bundler to try and install gems (at least for me it gave an error, but using pik gem install <gemname> worked).


Note that for the console I'm using the Windows DOS command line instead of cygwin

Installed Ruby via the Ruby installer

    Added Ruby to path as part of the installer option

Installed pik

D:\> gem install pik
D:\> pik_install <directory_in_PATH>

Ran pik

D:\> pik
D:\> pik list ## confirm proper Ruby version

Installed DevKit

Ran installer to %DEVKIT_HOME%

%DEVKIT_HOME%\> ruby dk.rb init
%DEVKIT_HOME%\> ruby dk.rb install

Test the DevKit installation

%DEVKIT_HOME%\> pik gem install rdiscount --platform=ruby
%DEVKIT_HOME%\> ruby -rubygems -e "require 'rdiscount'; puts Discount.new('**Hello there, Eric!**').to_html"
Should output 
<p><strong>Hello there, Eric!</strong></p>

Installed gems using pik

I didn't find a lot of pik usage information, but I decided to install gems with pik.  Using 'gem list' and 'pik gem list' in different consoles leads me to believe that the installation methods acheive the same result.  Pik dosen't appear to have native gemset-like commands, but see this post for a hack.
D:\> pik gem install bundler --pre
D:\> pik gem install rake
D:\> pik gem install activesupport
D:\> pik gem install mysql
D:\> pik gem install libv8
D:\> pik gem install rails
D:\> pik gem install execjs
D:\> pik gem install jquery-rails

Installed locally downloaded gems

D:\> pik gem install linecache19-0.5.13.gem


This one required the source code for my Ruby version
D:\> set RVM_SRC=<path_to_source>
D:\> pik gem install ruby-debug-base19-0.11.26.gem -- --with-ruby-include=%RVM_SRC%

Errors

Gem::RemoteFetcher::FetchError: SSL_connect returned=1 errno=0 state=SSLv3 read
server certificate B: certificate verify failed (https://rubygems.org/gems/<gem_name>)

I got this above error when running bundle install.  See this post for several fixes.  This one worked for me, but I had to create the destination directory before running the script.

Working on an existing Rails application in Ubuntu 12.04

My previous post described environment setup.  This post will focus on getting an existing application up and running.

Getting the application

I'm using Aptana and the existing project is on a bitbucket Mercurial repo.  Using the IDE I checked out the application.


The following commands are run from inside the project directory structure.

Bundler

Use bundler to get the appropriate gems for the project (see the file Gemfile).  I initially got errors due to missing packages on the Ubuntu side (postgresql-server-dev-all was not installed).


$ bundle

Database setup

Create databases

Looking at database.yml I see which databases I need to create.  Mine are postgresql (see the adapter fields) and two different databases.  Using psql's CREATE DATABASE <database_name> command I set both the test and  development databases up.

Create role

I needed to create a role for my Linux user using CREATE ROLE <role_name>

Populate databases

I needed to add execjs and therubyracer to my Gemfile.  I also needed to add `, :require => false` after my shoulda and shoulda-context gems in Gemfile per https://gist.github.com/1549790.  Per the link it seems that the load worked fine without the require => false.


$ rake db:schema:load

Run the application

$ rails server


http://localhost:3000 will display the RoR welcome screen.  You'll have to modify the URL based on your application.

Dude, where's my gemset?

If the .rvmc file for the project on which your working specifies a gemset that you don't have and/or that you didn't use to install the proper gems you can copy the one you did have setup to match the one specified in the file.  This is especially helpful if you want to use the Terminal in Aptana.

I needed to manually rerun the ruby debug installation because that failed during the copy.

$ rvm gemset list

$ rvm gemset copy 1.9.3-p194@<existing_gemset> 1.9.3-p194@<.rvms_gemset>

$ export RVM_SRC=$HOME/.rvm/src/ruby-1.9.3-p194
$ gem install ruby-debug-base19-0.11.26.gem -- --with-ruby-include=$RVM_SRC

Install Ruby on Rails development tools on Ubuntu 12.04

I ran into a number of issues installing this entire stack and then running a 1.9.3 / 3.2.0 application.  I won't detail the errors here.  The order here is somewhat important as the postgresql-server-dev-all was required during bundling.
Please see my next post for information regarding setup for a specific application.

Install postgreSQL

https://help.ubuntu.com/community/PostgreSQL

$ sudo apt-get install postgresql

$ sudo apt-get install postgresql-server-dev-all

Looks like database was initialized and started for me and user postgres was created.  I used ps -ef | grep postgres to figure out where the relavent directories used by my installation where.  The installation created the install in /usr/lib/postgresql/9.1 and the data directory as /var/lib/postgresql/9.1/main.  Configuration files in /etc/postgresql/9.1/main.

User postgres didn't have the postgresql bin directory on the path so I had to create a new .bashrc file for postgres so I don't have to reinitialize variables every time I open a console.  

export PATH=/usr/lib/postgresql/9.1/bin:$PATH

export PGDATA=/var/lib/postgresql/9.1/main

I modified pg_hba.conf to use the trust method so I wouldn't have to supply a password to the database.  This was done since the database.yml file that is part of the project assumes no password needed for db access.

Install adminpack to assist pgAdminIII

$ sudo apt-get install postgresql-contrib-9.1

$ sudo -u postgres psql < /usr/share/postgresql/9.1/extension/adminpack--1.0.sql

$ psql

postgres=# CREATE EXTENSION adminpack;

Install pgAdminIII

$ sudo apt-get install pgadmin3

Install Mercurial

$ sudo apt-get install mercurial

Install Aptana IDE

http://www.aptana.com/products/radrails

Install the Eclipse/Aptana MercurialEclipse plugin

Here's the update site:
http://cbes.javaforge.com/update

Install RVM

$ sudo apt-get update
$ sudo bash -s stable < <(curl -s https://raw.github.com/wayneeseguin/rvm/master/binscripts/rvm-installer)
$ source ~/.rvm/scripts/rvm
$ rvm get head && rvm-smile
$ sudo apt-get install libtool
$ rvm pkg install libyaml
$ rvm install ruby-1.9.3-p194

$ rvm --default use 1.9.3

Install Rails

$ gem install rails -v 3.2.0
$ gem install execjs
$ gem install therubyracer

Install bundler

http://stackoverflow.com/questions/6438116/rails-with-ruby-debugger-throw-symbol-not-found-ruby-current-thread-loaderro

$ rvm get stable
$ rvm use ruby-1.9.3-p194@<gemset_name> --create
$ wget http://rubyforge.org/frs/download.php/75415/ruby-debug-base19-0.11.26.gem
$ wget http://rubyforge.org/frs/download.php/75414/linecache19-0.5.13.gem
$ gem install linecache19-0.5.13.gem
$ export RVM_SRC=$HOME/.rvm/src/ruby-1.9.3-p194
$ gem install ruby-debug-base19-0.11.26.gem -- --with-ruby-include=$RVM_SRC
$ gem install bundler --pre

Dude, where's my gemset?

If the .rvmc file for the project on which your working specifies a gemset that you don't have and/or that you didn't use to install the proper gems you can copy the one you did have setup to match the one specified in the file.  This is especially helpful if you want to use the Terminal in Aptana.

I needed to manually rerun the ruby debug installation because that failed during the copy.

$ rvm gemset list

$ rvm gemset copy 1.9.3-p194@<existing_gemset> 1.9.3-p194@<.rvms_gemset>

$ export RVM_SRC=$HOME/.rvm/src/ruby-1.9.3-p194
$ gem install ruby-debug-base19-0.11.26.gem -- --with-ruby-include=$RVM_SRC