Insert HTML Tag Using Javascript...

The below mention function will be use to insert a div tag along with input field, button when a user clicks on hyper link. Button will be used to hide the selected div. A user can create max 5 div.


function attachFile(id)
{
var count = new Array("1","2","3","4","5")
var hiddenCount = document.getElementById("Cnt").value;
var Comman = 1;


for(var j=1;j<=count.length;j++)
{
if (id == 'remove_' + j)
{
document.getElementById('div_' + j).style.display = "none";
return
}
}
Comman = parseInt(hiddenCount) + Comman;
if (Comman <= 5)
{
var varTag1 = document.createElement("INPUT");
// var varTagRemove = newElement("input",{type:"button",name:"Remove",id:"remove_"+Comman,value:"1"},{onclick:attachFile(this.id)});
var varTagRemove = document.createElement("INPUT");
varTagRemove.type="button";
varTagRemove.value = "Remove";
varTagRemove.id = "remove_"+Comman;
varTag1.type = "file";
varTag1.id = "file_"+Comman;;
var x = document.all;
var br = "br"
if(x)
br = "
"
var varTag2 = document.createElement(br);

document.getElementById("div_" + Comman).appendChild(varTag1);
document.getElementById("div_" + Comman).appendChild(varTagRemove);
document.getElementById("div_" + Comman).appendChild(varTag2);
var rm_test = document.getElementById("remove_" + Comman);
rm_test.onclick = function(){attachFile(this.id)};
document.getElementById('Cnt').value = Comman;

}
else
{
for (var i = 1; i <= count.length; i++)
{
if (document.getElementById("div_" + i).style.display == "none")
{
document.getElementById("div_" + i).style.display = "block";
return
}
}
//ALERT WILL BE CALLED WHEN THE COUNT OF FILE UPLOADER IS 5 AND ALL THE DIV DISPLAY PROPERTY IS
// BLOCK
alert("Limit is over");
}
}

Ruby: How "send" method works?

Invokes the method identified by symbol, passing it any arguments specified. You can use __send__ if the name send clashes with an existing method in obj.
For example.
Suppose that in you have a three different parameter
1.addnum
2.subnum
3.multinum

depends on the parameter you want to call the method to execute add/subtract/multiply. So what you can do

class Number

def mainfunction(methodname, val1, val2)
#THE BELOW MENTION SEND METHOD WILL CALL ANY ONE METHOD #DEPENDS ON THE FIRST PARAMETER
self.send(methodname, val1, val2)
end

def addnum(val1, val2)
val1 + val2
end

def subnum(val1, val2)
val1 + val2
end

def multinum(val1, val2)
val1 + val2
end
end

num = Number.new
num.mainfunction(“addnum”, 10 , 20) #output => 30

So this is just a very basic example to understand hoe send method work.

How to enable grant access to remote system for MySQL server?

In a few step you can allow remote system to access your MySQL server. To implement first you will need to configure your my.cnf which which is located at

/etc/mysql/my.cnf [Debian Linux Environment]
OR
/etc/my.cnf [Red Hat Linux/Fedora/Centos Linux]
OR
/var/db/mysql/my.cnf [FreeBSD]

access the file using

sudo gedit /etc/mysql/my.cnf

check for following line
bind-address in which the local ip address is assigned 127.0.0.1
bind-address = 127.0.0.1
So just replace the local ip address with your server ip address e.g. 192.168.XXX.XXX
bind-address = 192.168.XXX.XXX

Thats it now all you need to restart your MySQL server and assign a grant access to remote system.

To restart MySQL server
etc/init.d/mysql restart

To assigned a grant access
GRANT ALL ON user_database_name.* TO remote_user_name@'192.168.x.x' IDENTIFIED BY 'PASSWORD';

Thats it and it is done.. Now
the remote user can access your db..

Configuration of phpMyAdmin on ubuntu..

Configuration of phpMyAdmin on ubuntu..
As you know that phpMyAdmin is a database management and adminstration tool. So below is given the installation process of phpMyadmin. Let assume that you have already installed LAMP on ur system.
And incase if you have not installed LAMP then follow the following steps.
1. Open the terminal.
2. install apache [sudo apt-get install apache2].
3. install php [sudo apt-get install php5 libapache2-mod-php5]
4. Once it is installed restart the apache [sudo /etc/init.d/apache2 restart]
5. Install MySQL server [sudo apt-get install mysql-server] and set a password to local system to gets root access.
6. Install MySQL admin [sudo apt-get install mysql-admin]
7. Install MySQL for Apache HTTP Server [sudo apt-get install libapache2-mod-auth-mysql php5-mysql phpmyadmin]
8. Edit your php.ini file to work your php with MySQL [pico /etc/php5/apache2/php.ini] and add following line [extension=mysql.so]
9. Again restart you apache same command used in point 4.
Now once your LAMP installed all you need to edit your apache2.conf file which is located in '/etc/apache2/apache2.conf' and add the following like
[Include /etc/phpmyadmin/apache.conf] and then restart your apache as given in point 4.
That it and your phpmyadmin is configured.

For accessing you can use the following URL "http://localhost/phpmyadmin/" and if it is configured on server or some other system just changed localhost from domain name.

Your comments are welcome.

How to install RMagick Gem on Ubuntu?

To install RMagick with image magick on ubuntu is very simple you just need to run three commands from your terminal. Just make sure that you have install ruby and rubygem.

Once your ruby and rubygem is install run the following command.
1. sudo apt-get install imagemagick
2. sudo apt-get install libmagick9-dev
3. sudo gem install rmagick

Thats it and Rmagick in installed on your ubuntu environment.

uninitialized constant Gem::GemRunner (NameError)

/usr/bin/gem:23: uninitialized constant Gem::GemRunner (NameError)

After installing ruby and rubygem on Ubuntu i started getting 'uninitialized constant Gem::GemRunner (NameError)' Error, so the solution for this is.
add the following command in your /usr/bin/gem
require 'rubygems/gem_runner'

Thats it and it will start working..

add_column new feature :after

Have created a new method, at the time of adding a new column in existing method. The method name is called :after
for ex
add_column :users, :user_info, :string, :after => "email"
when we execute the migration the email will be place just after user_info field in users table.

list of same column name from all the tables.

Hello Friend,
This time i'll tell you something about how we can know which table contains the same column name in a database.

[Note] This query only work in MySQL 5.02 and above

[Important]: - This query can help Ruby developer when they assigned a new project and if the project does not have a E-R diagram, As we never set a foreign key at a database level.
So here is the query

SELECT TABLE_NAME, COLUMN_NAME FROM information_schema.columns
WHERE COLUMN_NAME = user_id' AND table_schema = "test_development"

MySQL Database Dump from shell....

Hello Friends,
This is how we can take a database dump from command prompt.

1. Suppose you want to dump the entire database u can fire following command from cmd prompt...
"test_dump" will be your database name...
Your_location_where_you_want_to_save:\> mysqldump -u root -p test_dump > filename.sql


2. Suppose there are n numbers of table and we want to take a back of only 2 table let say table_abc, table_xyz from the "test_dump" database, so you can fire the below mention query...

Your_location_where_you_want_to_save:\> mysqldump --add-drop-table -u root -p test_dump table_abc table_xyz > filename.sql

Note: -
1. The filename can be anything.
2. Your_location_where_you_want_to_save = can be let say c drive c:\>

ERROR: While executing gem ... (Gem::InstallError)

Many developer had faced the issue at the time of installing rails 2.1.0 by using 'gem install rails'

ERROR: While executing gem ... (Gem::InstallError)

invalid gem format for c:/ruby/lib/ruby/gems/1.8/cache/activesupport-2.1.0.gem

So here is the solutions:

After doing some sort of R&D i found that you will need to download 'activesupport-2.1.0.gem' from http://rubyforge.org/frs/?group_id=570 site and first install activesupport manually. and then run 'gem install rails' from command prompt.

divide single word into sentence.

The below mention function will divide the long character word into specific sentence.
for e.g you have a input like "aaaaaaaaaaaaaaaaaaaa" you want this should be divide that means each sentence should contain 5 character "aaaaa aaaaa aaaaa aaaaa".


def word_division(char_length, comment_value)
return nil if comment_value.nil?
chunk_size = char_length
i = 0
chunks = []
while i < comment_value.to_s.length
chunks << comment_value.to_s[i,chunk_size]
i = i + chunk_size
end
return chunks.join(" ")
end

How to send a mail from application

After the configuration of action mailer. Perform the following task.

class Notifier < ActionMailer::Base
def send_email(user_details)
@recipients = "#{user[:email]}"
@from = "xyz@xyz.com"
@subject = "this is testing"
@sent_on = Time.now.utc
@content_type = "text/html"
@body = {}
url = "http://xyz.com/id=12312123"
@body.store('url', url)
@body.store('user', user)
render_message("signup", @body)
end
end


from controller call
def xyz
@user = User.new(params[:user])
if @user.save!
Notifier.send_email(@user)
end
end

and if you want a proper template should be forwarded then in ur view folder/notifier

create a file send_email.rhtml if you are using localization you can call as 'send_email_en.rhtml'
Dear, <%= @user[:login] %>
Welcome to xyz.com

thanks

About ActionMailer and condiguration of action mailer.

ActionMailer allows you to send email from your application, when you generate a action mailer
using following command: -
script/generate mailer Notifier
a action mailer class(inside model folder) and view generate.

Mailer methods have the following configuration methods available.

• recipients - Takes one or more email addresses. These addresses are where your email will be delivered to. Sets the To: header.
• subject - The subject of your email. Sets the Subject: header.
• from - Who the email you are sending is from. Sets the From: header.
• cc - Takes one or more email addresses. These addresses will receive a carbon copy of your email. Sets the Cc: header.
• bcc - Takes one or more email address. These addresses will receive a blind carbon copy of your email. Sets the Bcc header.
• sent_on - The date on which the message was sent. If not set, the header wil be set by the delivery agent.
• content_type - Specify the content type of the message. Defaults to text/plain.
• headers - Specify additional headers to be set for the message, e.g. headers ‘X-Mail-Count’ => 107370.

Configuration
1. First you need to configure action mailer with your application.
open environment.rb file or you can write it in a production/development file also.
after the 'Rails::Initializer.run do |config|' block
paste the below mention code

ActionMailer::Base.raise_delivery_errors = true #You may also turn exception raising on and off.
ActionMailer::Base.delivery_method=:smtp
ActionMailer::Base.smtp_settings = {
:address => "smtp.yourserver.com",
:port => 25,
#:domain => "www.mywebsite.com"
:user_name => "username",
:password => "password",
:authentication => :login # :plain, :login or :cram_md5
}
:domain is the name sent to the SMTP server during the handshake. It will be used to form the first “Received:” header, which spam filters usually check.

Installation of rails on linux

You can install rails in the following way...

gem install v1.1.6 rails

the version can be changed.

Installing Ruby Gem on Linux

Installation of ruby gem is also similar like installing ruby

cd /usr/src
if you are a root user then its fine else login as a root or simply pass the following command
su with the root password
wget http://rubyforge.org/frs/download.php/35283/rubygems-1.1.1.tgz
tar xzf ruby-1.8.6.tar.
ruby setup.rb

http://rubyforge.org/frs/download.php/35283/rubygems-1.1.1.tgz

Installing ruby on linux.

Here is a way through which you can easy install a ruby on your linux system

cd /usr/src
if you are a root user then its fine else login as a root or simply pass the following command
su with the root password
wget http://ftp.ruby-lang.org/pub/ruby/1.8/ruby-1.8.6.tar.gz
tar xfz ruby-1.8.6.tar.gz
./configure --prefix=/usr
make
make install
this is how one easy way you can install ruby.,