Next step : Creating the database for the filename application
The next phase or step would be to create a database for the application to use. Make sure the MySql engine is running and in the command window type “mysql -u root -p” and press enter and another enter for the password when prompted for there has not been any defined password yet. You are now logged into the engine as the root user and proceed to create the database by entering the following command “create database filename_development”. Also type in “grant all on filename_development.* to ‘ODBC’@'localhost’ this tells windows to grant access to a user named ODBC so you avoid an error when you try to access the said database from the command prompt. We next tackle the creation of tables that would allow the database to store the information we send it.
Database manipulation
The database has been initialized, so now we get down to business of defining the fields in that database and include a field that we would call a foreign key which allows the establishment of the one to many relationship between the tables. This part of the process requires quite a bit of background of database creation, manipulation and handling. It also requires knowledge regarding the workings of data types. So assuming you do not have much knowledge in such areas do some more reading to give you a better understanding of what how and why they are there. The ROR developers might say that it is very easy to do and use ROR but without the background on logic formulation, data types and manipulation as well as database handling the rest of the posts which would tackle ever hardening topics and operations would be very difficult to make sense of.
Don’t get me wrong, we just want to make life easier for you and not have you not understanding anything at all.
Next Step : Creating Empty Applications
Now that all has been set-up and is working, you should be able to create empty apps which is merely defining the application using rails which automatically creates all the necessary directories that are needed. Open a command prompt window and go to the directory where it was installed and proceed into the rails_apps directory. Type in ‘rails filename’ and rails creates all the necessary directories you would be needing for the development process. Don�t get freaked out when you see the multitude of directories for they will be filled out by “RAILS” and not by you manually. The next post will discuss some of the nuances of those dizzying directories to take some of the fog over them out.
Simplifying the previous program with modifiers
As said in the past post, there is an easier way of doing the stuff we did in the last program which would be very helpful when coding thousands of line of code when you do end up building your own programs is ruby.
class BookList
def [](key)
if key.kind_of?(integer)
result = @Books[key]
else
result = @Books.find { |aBooks| key == sBooks.name}
end
return result
end
end
Simplifying the code further by using the ‘if’ statement as a modifier it becomes a shorter easier to attain the same results as with the first program:
class Booklist
def [](key)
return @Books[key] if key.kind_of?(Integer)
return @Books.find { |aBooks| aBooks.name == key }
end
end
The use of the ‘find’ command in Ruby is simply a call to a function that is executed and it can be compared to a block call in many other languages such as Perl, C++ or Java.
Using the ‘yield’ statement
It might be almost similar but relatively different in a big way for blocks may appear only in the source adjacent to a method call which means it should be written on the same line as the method’s last parameter and it is not implemented once it is encountered but, Ruby rather remembers the context by which the block of code appears then enters the method. Within the method itself, the block of code may be called as if it were a block in itself by using the ‘yield’ statement. After the block of code has been executed, control returns immediately right after the call to the yield statement. Sample use of ‘yield’:
def threeTimes
yield
yield
yield
end
threeTimes {puts “Hi There”}
About Ruby on Rails
An open source web application framework written in Ruby is commonly known as RoR (Ruby on Rails). It was designed to make web development faster, simpler and more efficient and it also used to develop real-world application with less code, compared to other application frameworks. Ruby on Rails divides itself into various packages, namely Active Record, Active Resource, Action Pack, Active Support and Action Mailer.
Ruby on Rails Chases Simplicity in Programming
Ruby on Rails has focused on creating templates and designs that tackle the unglamorous problems. It is not also to create a sophisticated development framework that the engineers at Google or Amazon.com will flock to; it is like making a database modification that the great majority of Web developers face every day.
How to Install Ruby on a Shared Web Host
by Chubs
Create a directory for all of the software you are going to download and installed. In this example, the created directory is “temp” at the root of the files system, but you can use any name and location you like.
cd /
mkdir temp
chmod 775 temp
Now, download, configure and install Ruby. You can download the latest stable source tarball for Ruby here. Wget is used in this example:
cd temp
wget ftp://ftp.ruby-lang.org/pub/ruby/ruby-1.8.2.tar.gz
tar -zxvf ruby-1.8.2.tar.gz cd ruby-1.8.2
Specify an install directory since there are times when you won’t have permissions to install things in normal directories. Here, we can see the “configure” script for Ruby, creating a directory inside “/usr/local” for installation:
./configure –prefix=/usr/local/ruby –exec-prefix=/usr/local/ruby
Now, you have a Makefile that you can compile:
make
make install
Your Ruby is now installed. You should try making a symbolic link to Ruby somewhere in your local path:
ln -s /usr/local/ruby/bin/ruby /usr/local/bin/ruby
How to Install RubyGems and Rails on a Shared Web Host
by Chubs
RubyGems or Gem allows you to install extra packages and libraries for Ruby. You need Gem before installing Rails. You can get the latest version of RubyGems here.
cd /temp
wget http://rubyforge.org/frs/download.php/3700/rubygems-0.8.10.tgz
tar -zxvf rubygems-0.8.10.tgz
cd rubygems-0.8.10
To install RubyGems, you need to use Ruby to call the setup script:
ruby setup.rb
Here, you should see “Successfully built RubyGem” if it’s finished. Next, open the file “/usr/local/ruby/bin/gem” in your favorite text editor (such as vi) and edit the first line so you’ll know where to find your custom Ruby installation. Example:
#!/usr/local/bin/ruby
Now, add a few more symlinks:
cd /usr/local/bin
ln -s /usr/local/ruby/bin/erb erb
ln -s /usr/local/ruby/bin/eruby eruby
ln -s /usr/local/ruby/bin/gem gem
ln -s /usr/local/ruby/bin/gem_server gem_server
ln -s /usr/local/ruby/bin/testrb testrb
ln -s /usr/local/ruby/bin/update_rubygems update_rubygems
RubyGems is now installed. To install Rails, use:
gem install rails –remote
Ruby – Still on the Sidelines?
Ruby has long been fighting for recognition in the world of open-source development and in the past few years, it surely has managed to go mainstream with some major development projects. One surprising fact when it comes to overall popularity, recent development surveys show that use of the scripting language has jumped by 40% which may be sign that people are embracing more options in their drive to lower all costs with regard to the newer versions of the many flavors being used all over the globe. The updated Ruby on Rails 2.3 is a bit better and easier to use compared to previous to older versions and with the recession putting the brakes on many projects being planned, alternate methods of development and deployment have to be found to allow enterprise to continue with their plans with less costs. Keep on reading!