So long and thanks for all the fish

I have not made many posts for a while on this blog. Out of frustration with posting code samples and interest of writing sinatra web applications I have setup on webfaction please view http://lizard-spock.co.uk from now on my new posts will be here. Also my sourceforge/opensource projects will be moved here. Update: software projects no longer available

Github embeded example

GIT setup on webfaction

git is a popular revision control system which allow users to make local commits to capture their work in progress before it is pushed to the central repository. Most webfaction servers do not currently have git installed so you will have to compile it your self fairly trivial if you follow the instructions.

The intended work-flow is to keep committing local changes while you work on you r website and when you are happy with it you push to a secure git repo. Then make your webapp pull from the central secure repo.

$ shh username@username.webfaction.com
$ cd ./bin
#//Check out the latest version, currently it is 1.7.0.2
$ wget http://kernel.org/pub/software/scm/git/git-1.7.0.2.tar.gz
$ tar zxf git-1.7.0.2.tar.gz
$ cd git-1.7.0.2
$ ./configure --prefix=$HOME && make && make install

#//Clean up the original stuff leaving the compiled binaries in ~/bin
$ cd ~/bin
$ rm -rf git-1.7.0.2*
#//This bring the total from 80MBs down to 14MBs

$ mkdir ~/repo/projectname.git
$ cd ~/repo/projectname.git
$ git --bare init

Now local stuff to connect it

$ cd /path/to/your/local/repository/
$ git init #Assumes it is not already a git repo
$ touch README.md
$ git add README.md
$ git commit -a -m '*Added README.md'
#//Now try to connect to server, will request your ssh password or not if you have key based ssh auth setup
$ git push ssh://user@user.webfactional.com/~/repo/projectname.git

You will see this error

$ bash: git-receive-pack: command not found
$ fatal: The remote end hung up unexpectedly

This is because of an oddity in the way the .bash_profile and .bashrc are setup.
ssh only loads the .bash_profile.

.bash_profile

# .bash_profile
  
  # Get the aliases and functions
  if [ -f ~/.bashrc ]; then
     . ~/.bashrc
  fi
    
  ## MOVE THIS TO .bashrc THENthey Will both be the same
  # User specific environment and startup programs
  #PATH=$PATH:$HOME/bin
  #export PATH

.bashrc

# .bashrc

# Source global definitions
if [ -f /etc/bashrc ]; then
        . /etc/bashrc
fi

# User specific environment and startup programs
PATH=$PATH:$HOME/bin
export PATH
# User specific aliases and functions

NB: The following may be added so you can use the 'git push' shortcut (it actually runs git push origin master).

$ git remote add origin ssh://user@server-ip-or-address/~/repo/projectname.git

$ git push origin master
$ git push

Based on http://devioustree.co.uk/2009/07/23/setting-up-git-on-webfaction/
and http://docs.webfaction.com/software/git.html

Webfaction and google apps

First register (for free) with standrad google apps

Create the random subdomain (under domains) that google gives you.
Then under DNS overides choose the new subdomain and complete the CNAME record to be google.com

Check that this has taken affect. when you press the I have done this button google then checks. If you hae not done this it will assume that you do not own the domain and not allow you to continue.

For easy access to your mailbox, create a new subdomain (under domains) mail.yourdomain.com. Then under DNS overides set the CNAME to ghs.google.com

Then under domains for yourdomain.com create these MX records

Domain                Priority
ASPMX5.GOOGLEMAIL.COM   30
ASPMX4.GOOGLEMAIL.COM   30
ASPMX3.GOOGLEMAIL.COM   30
ASPMX2.GOOGLEMAIL.COM   30
ALT2.ASPMX.L.GOOGLE.COM 20
ALT1.ASPMX.L.GOOGLE.COM 20
ASPMX.L.GOOGLE.COM      10 

Setting Up on WebFaction

WebFaction is quite popular among the Python and Django community, recently it has simplified Rails and other Ruby web frameworks.

Unlike other Web hosts they do not bundle a domain name, but these can be bought quite cheaply from www.gandi.net. I would then forward the MX records to google and get a gmail handler for your mail. You do not have to get a domain straight away by default you can use username.webfactional.com

First I had to install Passenger (I think this is also called Rack), I set the name to passenger.

This means that if you ssh/sftp/ftp into your account you will see ~/webapps/passenger/

Then I entered the Websites section then created a new subdomain devel.username.webfactional.com and set this to be type:passenger location:/

I had to wait sometime before these setting became active.
There article can then be followed for setting up a basic Sinatra over passenger (Rack).

NB: for a sinatra app you only need to install Passenger (not rails) and gem install sinatra (plus sequel / activerecord etc).

Sinatra set_cookie started failing

I recently started getting this error [1] in my Sinatra web application (after upgrading from 0.9.4 to 0.9.6)

[1] undefined method `set_cookie' for 

Basically instead of

set_cookie("foo", "bar")

We now have to use:

response.set_cookie("foo", "bar")

Source gitr

VIM and whitespace

To view white space characters (except spaces)

:set list

To stop tab insertion and uses spaces

set expandtab

To set all types of tabs to 3 spaces

set tabstop=3
set softtabstop=3
set shiftwidth=3

Further Info vimcasts.org 2

RubyGem version error: activesupport(1.4.4 not = 2.3.2)

I have been getting this error [1] when trying to set up a ORM lesson for ActiveRecord. Specifically trying to use active record inside of a Rake file.

[1]RubyGem version error: activesupport(1.4.4 not = 2.3.2)

$ gem list
*** LOCAL GEMS ***

abstract (1.0.0)
actionmailer (2.3.5)
actionpack (2.3.5)
activerecord (2.3.5)
activeresource (2.3.5)
activesupport (2.3.5)
acts_as_taggable (2.0.2)
compass (0.8.17)
erubis (2.6.5)
feed-normalizer (1.5.1)
haml (2.2.17)
hoe (2.3.3)
maruku (0.6.0)
mbleigh-acts-as-taggable-on (1.0.5)
mysqlplus (0.1.1)
ncurses (0.9.1)
rack (1.0.1)
rails (2.3.5)
rake (0.8.7)
rubyforge (1.0.4)
sequel (3.8.0, 3.7.0)
simple-rss (1.2)
sinatra (0.9.4)
sqlite3-ruby (1.2.5)
syntax (1.0.0)

activesupport 2.3.5 does seem to be present. but it was fixed by running:
$ gem install activesupport

HTML CSS id vs class

Working on some websites again, been away from HTML and CSS for a while and having to remind myself the difference between ids and class's.

id is for unique elements on a page. There should only ever be one of each id on a page.

< d i v id="navigation">< / d i v>

class is for many elements which you want to apply a custom style

< p r e  id="prettyprint">Code1< / p r e>
< p r e  id="prettyprint">Code2< / p r e>

CSS for id:

div#navigation {background-color: white;}

CSS for class:

div.prettyprint {background-color: white;}

Original Source :
http://www.tizag.com/cssT/cssid.php

Disable Visio Auto Connect

I think it was in Visio 2007 a new feature called auto connect was added which adds blue triangles on the side of visio objects (Shown in image below) and if pressed will auto connect to some other object/shape. This can get quite furstrating as they are very easy to accidentally click.



To switch off this feature choose:
Visio -> Tools -> Options -> General Tab
Deselect the 'Enable AutoConnect' option

.vimrc tweaks

Improving the Status line in Vim, get current file, directory, position etc.

~/.vimrc

"Setup the Status line
set showcmd             " shows the command in the status line
set ch=2                " make command line 2 lines high
set ls=2                " status line always on

set statusline %<%f\ %h%m%r%=%{getcwd()}\ \ \ %-14.(%l,%c%V%)\ %P

Java right click menu example

I have just setup a new github project for java examples first source file is the basic structure of a right click menu.

PopupMenu.java

Sinartra limit blog posts displayed on a page

To limit the number of database elements returned in ActiveRecord is trivial but there is a little bit of work involved with getting the links setup to jump forward and backwards.

I have decided to use these [1,2,3] URLs to navigate the list of blog posts
[1] /blog : always the latest
[2] /blog/older : The next page of blog posts
[3] /blog/older/integer : a page of blog posts starting at integer the links provided will increment this by a fixed amount, but the route can accept any value.

NB: as allways I have inserted some extra space in to the code to get it to display rather than render, you may have to delete spaces after <.

My app.rb:

require 'rubygems'
require 'sinatra'
require 'active_record'

$blogpath = "blog"
$blogs_per_page = 10

ActiveRecord::Base.establish_connection(
  :adapter   => 'sqlite3',
  :database  => './db/blog.db'
)

class Posts < ActiveRecord::Base
end

get '/blog/?' do
   @offset = 0
   @posts  = Posts.find(:all, :order => "id DESC", :limit => $blogs_per_page)
   erb :'blog/all'
end

get '/blog/older/?' do
   #This probably should be a redirect to /blog/older/$blogs_per_page
   @offset = $blogs_per_page
   @posts  = Posts.find(:all, :order => "id DESC", :limit => $blogs_per_page, :offset => @offset)
   erb :'blog/all'
end

get '/blog/older/:offset/?' do
   @offset = params[:offset].to_i
   @posts  = Posts.find(:all, :order => "id DESC", :limit => $blogs_per_page, :offset => @offset)
   erb :'blog/all'
end

The views/blog/all.erb

< %# This section adds control on top  %>
< p>
< a href="/<%=$blogpath%>"> latest <%=$blogpath%>< /a> 

<% if @offset>($blogs_per_page-1) %>
 | < a href="/<%=$blogpath%>/older/<%=@offset-$blogs_per_page%>"> newer <%=$blogpath%>< /a>
<%end%>

 | < a href="/<%=$blogpath%>/older/<%=@offset+$blogs_per_page%>"> older <%=$blogpath%>< /a> 
< /p>

<%# This section lists all the Posts passed to it %>
<% for post in @posts %> 
  < h2>< a href="/<%=$blogpath%>/<%=post.id%>"> <%= post.title %>< /a>< /h2>
  < p><%=post.body%>< /p>
<% end %>

Hyperlink to submit html forms

Some times you need a hyperlink to submit hidden form data. Example taken from javascript-coder.

< form name="myform" action="handle-data.php">
Search: < input type='text' name='query' />
< a href ="javascript: submitform()">Search< / a>
< / form>
< script type="text/javascript">
function submitform()
{
  document.myform.submit();
}
< / script>

This is a suggestion from VelocityReviews, just change the look of the button:

< input type="submit" value="Submit" style="Border: none; background: none">

I ended up using a hyperlink to an URL that could then be intelligently parsed in my sinatra route, I would have had to have seperate get and post routes any way if I wantyed to stop the form appending ?lots=of&variab=les to the URL.

Sinatra layouts vs templates

I must have missed this on my first pass of the Sinatra (sinatrarb) book. There is a very nice way to create a site template, called a layout.

Just create a file in views called layout.erb (or layout.haml if using haml) output yield where you want the body of the templates to be inserted. Class @variables can also be used.
This allows the basic layout of your site Headers, Footers and navigation panes to be controlled independently, a change in layout.erb is instantly applied across your whole site.

layout.erb

< h t m l>
   < h e a d>
      < t i t l e><%= @title %>< / t i t l e>
   < / h e a d>
   < b o d y>
      <%= yield %>
   < / b o d y>
< / h t m l>

you app.rb (NB: no refference to layour.erb is made)

get '/about/?' do
   @title = "About"
   erb :about
end

/views/about.erb

<p>Example about page</p>

SASS with Sinatra

Have started looking onto how to use use stylesheets with Sinatra. The easiest way way is to have a top level folder called Public with your main.css file.

This can be referenced from all pages as

< h t m l>
   < h e a d>
      < t i t l e> example < / t i t l e>
      < l i n k href="/main.css" rel="stylesheet" type="text/css" />
   < / h e a d>

Standard stylesheets have no have variables, they say they do but I could not get them to work. So I have started to look at compass which is a framwork for CSS! it based on haml which is another templating language like erb.

The Main Compass page. Integrating it with Sinatra.

Also see github for a basic example of using Sinatra and Compass.

Example of some SASS:

!cdark =    rgb(145, 129, 107)
!cdarker =  rgb(125,  91,  95)
!clight =   rgb(141, 189, 168)
!clighter = rgb(23 , 206, 143)

body 
   background-color: #{!cdark}

p
   color: #{!clight}

Compass uses SASS and is built on the blueprint layout system.
Blueprint Tutorials.

Java and Ant setup on Windows XP

Setting up a Windows XP machine for creating/testing java builds. These programs are required:

Java JDK
ant, for more automated builds (like make and rake)
JSmooth, creates .exe from jar files.
Zip Genius, for unpacking the .tar.gz source files.

Download and install the Java SDK.

Download ant, put contnets of .zip in C:/Program Files/ant/
Now go to Control Panel -> System -> Advanced tab and press the set Environment Variables

Create these two new variables

Variables	Value
JAVA_HOME	C:\Program Files\Java\jdk1.6.0_18
ANT_HOME	C:\Program Files\ant\apache-ant-1.8.0RC1

Edit Path to include ant bin and java JDK bin,
C:\Program Files\ant\apache-ant-1.8.0RC1\bin;C:\Program Files\Java\jdk1.6.0_18\bin;

JSmooth and zip Genius should download and install like standard windows programs


NB: I Kept getting this error when trying to run ant
> ant
Unable to locate tools.jar. Expected to find it in C:\Program Files\Java\jre6\li
b\tools.jar

JAVA_HOME does not point to the bin folder but the folder above 'C:\Program Files\Java\jdk1.6.0_18' quotes not to be included.

VMware Fusion Disk Usage

The disk images for the operating systems are sparse, i.e. they expand as necessary. They unfortunately do not shrink automatically when you delete data.

For a windows image you have to install the VMware tools to shrink the disk.
VMware guide
http://www.vmware.com/support/ws5/doc/ws_disk_shrink.html

The VMware Tools are installed by: Start your virtual Operating system -> Move mouse to the top of the screen and select 'Virtual Machine' -> 'Install VMware Tools'

VMware Tools location
C:\Program Files\VMware\VMware Tools\VMwareControlPanel

Java String Search and Replace

Java by default by default only searches for regular expressions and replaces with strings. The method below allows String search and string replace.

Why is regular expression search an issue ? if search for [ex] it will match 'e' and 'x' but not '[ex]' if you have control over thestring you could excape the special characters with '\[ex\]' but if you are loading from a config file and you know it is plain text then it would be nice if there was a simple search and replace function example supplied below:

public String replaceString(String input, String find, String replace, boolean casesensitive){
 String input_case_adjusted = input;
 if (casesensitive == false) {
  //For Case Insensitive searchs
  //Lowercase everything (but replace in the original string)
  input_case_adjusted = input.toLowerCase() ;
  find                = find.toLowerCase() ;
 }
 
 int    startPosition = input_case_adjusted.indexOf(find);
 String start         = "";
 String end           = "";
  
 if (startPosition >= 0) {
  if (startPosition > 0) {
     start = input.substring(0, startPosition);
  }
  end = input.substring(startPosition + find.length());
   
  return start + replace + end;
 } else {
  return input;
 }
}

Java case insensitive regular search and replace

Java's Search and replace function on strings is:

new_string = old_string.replaceFirst(regularExpresionFind, textReplace);

To make this non-case sensitive / case insenitive:

new_string = old_string.replaceFirst("(?i)" + regularExpresionFind, textReplace);

Audio File Tag Editor

The best MP3 tag editor I can find is Mp3tag (supports most audio files). The feature that I find most useful is its ability to parse the file name and writing it into the tags and vice versa. Unfortunately it is windows only.

Happy New Year, Have some Tabs

File Explorer (my souceforge project) now has tabbed browsing and right click open folders in new window or new tab.