Checkbox select all jQuery plugin for a table

/*
 * File: jquery.checkboxselection.js
 *
 * Plugin to create checkbox in the table
 * It needs table has correct structure (at least with head and body) and
 * there are checkboxs in row's first cell both in header in body
 */

(function($) {
    $.fn.checkboxSelection = function() {
        return this.each(function() {
            var table = this;
            var headCheckbox = $('thead th:first :checkbox', table).click(function() {
                $('tbody tr', table).find('td:first :checkbox').attr('checked', this.checked);
            })
            var checkSelection = function() {
                var trs = $('tbody tr', table).find('td:first');
                headCheckbox.attr('checked', trs.find('input:checked').length == trs.find(':checkbox').length);
            }
            $('tbody tr', this).find('td:first :checkbox').click(checkSelection);
            checkSelection();
        });
    }
})(jQuery);

HTML:

<table>
    <thead>
        <tr>
            <th><input type="checkbox"></th>
            <th>Name</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td><input type="checkbox" name="a[1]"></td>
            <td>John Smith</td>
        </tr>
        <tr>
            <td><input type="checkbox" name="a[2]"></td>
            <td>Jack Daniels</td>
        </tr>
    </tbody>
</table>

Using:

$('table').checkboxSelection();

How to limit joined records in MySQL

I have to tables with one-to-many relationship. I needed to select all from the master table and join only one record which contains the oldest date.
The solution is:

SELECT parent.*,
       c1.*
  FROM parent
       JOIN child c1
          ON c1.parent_id = parent.id
       LEFT JOIN child c2
          ON c2.parent_id = c1.parent_id AND c2.sort < c1.sort -- field to determine the order (maybe whatever you want)
GROUP BY parent.id,
         parent.name,
         c1.id,
         c1.name
HAVING COUNT(c2.id) < 1 -- limitation of joined records
ORDER BY parent.name, c1.name;

I found it there.

ATI driver problems after upgrading Ubuntu 9.10 to 10.04

I have upgraded my desktop Ubuntu 9.10 to 10.04. Everything was fine except ATI driver didn't want to be installed. An error was in fglrx-amdcccle package,After that, I've reported the bug to Ubuntu Bug Tracker, and today I got the decision of my problem:

apt-get remove xorg-driver-fglrx fglrx fglrx-amdcccle
dpkg-divert --remove /usr/lib/xorg/modules/extensions/libdri.so
dpkg-divert --remove /usr/lib/xorg/modules/extensions/libglx.so
apt-get install fglrx

I thank Jean-Baptiste Lallement for help!

Check class

In case if you have to use pure Javascript:

    var hasClass = function(element,className) {
        return (function() {
            var classes = element.className.split(' ');
            for(var i in classes) {
                if(classes[i] == className) {
                    return true;
                }
            }
            return false;
        })();
    }

CSS attribute selectors

[rel=value] — attribute equals to value

<h1 rel="value">Attribute Equals</h1>

h1[rel=value] { color: red; }

[rel*=value] — attribute contains value anywhere

<h1 rel="xxxvaluexxx">Attribute Contains</h1>

h1[rel*=value] { color: red; }

[rel^=value] — attribute starts with value

<h1 rel="value-link yep">Attribute Begins</h1>

h1[rel^=value] { color: red; }

[rel$=value] — attribute ends with value

<h1 rel="friend value">Attribute Ends</h1>

h1[rel$=value] { color: red; }

[rel~=value] — attribute contains value in space-delimited list

<h1 rel="friend value sandwich">Attribute Space Separated</h1>

h1[rel~=value] { color: red; }

[rel|=value] — attribute contains value in dash-delimited list

<h1 rel="friend-value-sandwich">Attribute Dash Separated</h1>

h1[rel|=value] { color: red; }

Table checkboxes selection

To select or unselect checkboxes in a table I use the follow code

(function() {
    // checkboxes in the table
    var cbs = document.getElementsByName('checkboxes');
    // header checkbox
    var all = document.getElementById('header_checkbox');
    all.onclick = function() {
        for(var i=0;i<cbs.length;i++) {
            cbs[i].checked = this.checked;
        }
    }
    var cbClick = function() {
        all.checked = (function() {
            for(var i=0;i<cbs.length;i++) {
                if(cbs[i].checked != true) {
                    return false;
                }
            }
            return true;
        })();
    }
    for(var i=0;i<cbs.length;i++) {
        cbs[i].addEventListener('click', cbClick, true);
    }
})();

Universal archive unpacking tool

###   Handy Extract Program

extract () {
    if [ -f $1 ] ; then
        case $1 in
            *.tar.bz2) tar xvjf $1   ;;
            *.tar.gz)  tar xvzf $1   ;;
            *.bz2)     bunzip2 $1    ;;
            *.rar)     unrar x $1    ;;
            *.gz)      gunzip $1     ;;
            *.tar)     tar xvf $1    ;;
            *.tbz2)    tar xvjf $1   ;;
            *.tgz)     tar xvzf $1   ;;
            *.zip)     unzip $1      ;;
            *.Z)       uncompress $1 ;;
            *.7z)      7z x $1       ;;
            *)         echo "'$1' cannot be extracted via >extract<" ;;
        esac
    else
        echo "'$1' is not a valid file"
    fi
}

Поместить в ~/.bashrc или profile

original

Setting up a network adapter alias

sudo ifconfig eth0:[0-254] 192.168.1.2 up.

Instead of eth0 you can use any of existing interfaces

Firefox extension. Thoughts.

While I try to see into Firefox Extension development, I found not evident things for me. And here I'll list'em.

• You want to append event handler to created by you DOM-element somewhere in '1body' descendants. Don't try to use onclick or like it - you'll get a fail. Use addEventHandler method, and you'll get success :)
  

Django model field inheritance

To inherit model field in Django is not enough simply inherit a field class. It is needed to add attribute __metaclass__ = models.SubfieldBase. After that, you can overload any method you want.

Firefox extension. The first tries

I am developing the service which I'll describe further. And I decide to create a Firefox extension for it. And what I have dug:

• To create a developer profile may that
  

  firefox -profilemanager

• To run another -- development -- copy of Firefox
  

  firefox -no-remote -P <profile name>

And I assume firefox binary in your path.

Django and Oracle support

To get work Django and Oracle client in Ubuntu:

Download cx_Oracle (choose for your system), Oracle InstantClient and Sql*Plus (in this page you can choose your OS and download the packages (in my case are oracle-instantclient11.2-basic-11.2.0.0.2-1.x86_64.rpm and oracle-instantclient11.2-sqlplus-11.2.0.0.2-1.x86_64.rpm).

Move the files into one directory for simplicity and run

alien -k *.rpm
dpkg -i *.deb

to convert all the downloaded packages to ubuntu deb-format and install them.

Then make symlink to lib, otherwise module won't be found by Django

cd /usr/lib/python2.6
ln -s site-packages/cx_Oracle.so

To avoid

Traceback (most recent call last):
  File "", line 1, in 
ImportError: libclntsh.so.10.1: cannot open shared object file: No such file or directory

add to ~/.bashrc (or /etc/bash.bashrc to system-wide apply)

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/lib/oracle/11.2/client64/lib

If you see the message

Traceback (most recent call last):
  File "", line 1, in 
ImportError: libaio.so.1: cannot open shared object file: No such file or directory

run

sudo apt-get install -y libaio1

P.S. If you choose more modern (or older) version of Oracle IntstantClient you have to create symlinks for necessary version, e.g. you see the following error:

Traceback (most recent call last):
  File "", line 1, in 
ImportError: libclntsh.so.10.1: cannot open shared object file: No such file or directory

but in /usr/lib/oracle/11.2/client64/lib directory exists libclntsh.so.11.1. Just make it symbolic link with

ln -s libclntsh.so.11.1 libclntsh.so.10.1

Install RPM in Ubuntu

To install Rpm-package in Ubuntu Linux (to run commands needs to be a superuser or using sudo):

1. install alien package:

   sudo apt-get install alien

2. Convert Rpm to Deb (in current directory)
   

   alient -k <package-file>.rpm

3. Install the new Deb package
   

   dpkg -i <package-file>.deb