ruby-on-rails-tips-blog

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RabbitMQ with Ruby on Rails in 2018 for Web Application Development

An Introduction to RabbitMQ:

RabbitMQ is a message broker software in Ruby on Rails development where web applications connect to the queue and transfer a message onto it. When one application server sends the request to another application server, RabbitMQ works as a queue manager where requests handled and served one by one. Message transferring is done from one application to another through RabbitMQ.

RabbitMQ uses the standard Advanced Message Queuing Protocol (AMQP) to keep message request in queues and serve easily. The message may contain any information like simple text transfer or task that need to process on another server. This RabbitMQ software saves messages in a queue and keeps in a queue until receiving application get connected and start processing the messages.

Why should we use RabbitMQ in Ruby on Rails Development?

Message broker works on the producer, broker, and consumer logic. Message broker server allows consumer and producer server to respond request fast instead of using resources heavily at one time. The message broker is used to optimize the load on the server and provide services until application executes the task on the requested server. The requested server can be any third party application which performs the task.

Queued messages will be used to send the messages or task to multiple recipients from consumption that leads to the load balancing on the producer and consumer server.

Let take an example of ruby on rails server and bitcoin exchange server (i.e. bitcoind) for btc transaction working.

I have rails server running as producer and bitcoind server as a consumer.

Rails server send multiple request to bitcoind server continuously. There may be chances to slow down bitcoind because of multiple requests send to bitcoind server to process task.

In that case, RabbitMQ can fulfill the role of load balancing and messages passing by keeping the request coming from rails server in a queue and serve request one by one to bitcoind server.

Bitcoind server will take a task from the queue and start processing.

                                                       AMQP role in RabbitMQ:

AMQP store and forward messages to consumers, same as SMTP protocol which is used to deliver mail to mailboxes. Messages start from producer application to the exchanges that help to redirect in queues. Lastly, queues deliver task to the consumer application. It's now consumer's server responsibility to take the messages from queues to process as required.

A virtual channel is used to establish the connection between publishing messages from the queue. All process exchanges done over the channels.

How to use RabbitMQ in Rails application?

Using Bunny ruby RabbitMQ client, we can integrate RabbitMq with rails application. There are some gems available to start with RabbitMQ in ruby like

gem “bunny”

Bunny help rails application to interoperate with the consumer application, it can be built in any technologies irrespective of the size and complexity of the application. Also, add anampq gem in rails Gemfile to use AMQP protocol services.

  gem  ‘amqp’

RabbitMQ installation commands in Ubuntu:

1] Step 1: Update system  

sudo apt-get update

2] Step 2: Install Erlang

RabbitMQ is written in Erlang, you need to install Erlang before you can use RabbitMQ:

a] wget http://packages.erlang-solutions.com/site/esl/esl-erlang/FLAVOUR_1_general/esl-erlang_20.1-1~ubuntu~xenial_amd64.deb

b] sudo dpkg -i esl-erlang_20.1-1\~ubuntu\~xenial_amd64.deb

3] Step 3: Install RabbitMQ

     sudo apt-get installrabbitmq-server

4] Step 4: Start the Server

  sudo systemctl start rabbitmq-server.service

  sudo systemctl enable rabbitmq-server.service

Thus if you are looking for web development services which are faster, reliable, redundant and scalable then you can definitely opt for Ruby on Rails RabbitMQ. Hire RoR developers for developing a robust messaging software.

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Action Cable is a powerful feature introduced in Rails 5. Using action cable one can develop real-time web applications. Action cable uses Web Sockets to create full duplex communication between application’s server and client.

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What is Automated Software Testing and When Choose Automation Over Manual Testing?

As software testing is moving from the manual into automation at very fast speed, at times testers get into a scenario where they need to opt what needs to be automated, when to automate and why to opt for automated software testing?

If you are a software tester, this blog will help you to choose one from the two testing methods.

Software testers generally perform manual testing in the following scenarios:

1. When an application is at the initial stage of development. As application flow and feel and change over developing period it's better to go for manual testing then automating it. Automation can be done only when the application is stable.

2. When negative testing of the application is to be done because it's more reliable to depend on manual testing.

3. When regression is not required multiple times i.e. there are no multiple executions of test cases.

4. When there are some functionalities which cannot be automated like Captcha.

What is Automated Software Testing?

It is a process in which specific tools are used to execute scripts or test and compare the results. There are various tools available in the market to automate different types of software testing like QTP, Selenium, etc.

Starting with automation first need to take in consideration the following to avoid any confusion.

1. Is the build stable?

2. Does the application requires testing same functionality many times(Regression/Sanity/Smoke)

3. Will writing automated test case save time?

4. Do we have that much time to invest in automated testing?

If the answer to this question is YES then you can opt for automation testing for the application. Choosing the right framework for application is all dependent on what you are going to test.

And yes a team of experts for software testing to carry out the process is really important aspect followed by proper planning and strategy.

When to Choose Automated Software Testing?

1. Regression Testing: When we need to test the same test case or functionality multiple times. As testing the same functionality manually make people bore and error chances increase.

2. Large No. of Test Cases: When there is a large number of test cases to execute, it’s better to go with automation where just running the test suite will solve the problem.

3. Time management: As said above executing a large number of test cases manually will take a lot of time and money. So the time can be saved if we are using automation testing.

4. Performance: It's not possible to invest thousands of users to test the performance of any application. Automated testing can generate the required amount of user to interact with application and network.

5. Accuracy: It can be obtained with the help of regression/sanity/smoke testing: one has to just run the script. Manually there is a chance of missing any scenario.

[ruby-on-rails-tips-blog]

In Ruby programming, there are many methods for Array object i.e. Map, Collect, Select, Reject, Each, Inject, Reduce, Detect and Find. Most of the Ruby on Rails developers use these methods in their web applications.

[ruby-on-rails-tips-blog]

If you want to create Rails Application dependent on API only and you have a requirement to provide Token based authentication in your application. So you can use JWT+ KNOCK token based Authentication solution.

[ruby-on-rails-tips-blog]

Unit testing is the initial level of software testing, that is performed on the application source code mainly by the developer. The main motive of Unit Testing is to isolate a section of code and verify it’s correctness.

[ruby-on-rails-tips-blog]

Angular is a TypeScript-base open-source front-end platform and framework led by the Angular Team at Google used for building client-side web applications. Angular itself is written in TypeScript, which is a superset of JavaScript

[ruby-on-rails-tips-blog]

Font Awesome 5 is upgraded version of Font Awesome 4, It has a more attractive icon with big improvement icons as compare to Font Awesome 4

[ruby-on-rails-tips-blog]

Every University has thousands of applications streaming in for each course. A single application has a minimum of three stages – the document submitted by the student, his/her interview and finally, uploading the financial proof. Managing all of this singularly is a huge challenge.

There is a strong need for providing a common platform for application management. Offshore System for Student Management, a software developed using Ruby on Rails technology.

[ruby-on-rails-tips-blog]

Redis is used when we have a performance issue related to scalability. For example when we have data in the database which is not going to change frequently then you use Redis to cache that data to remove the load from the MySql or PgSql server.

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How to deploy Ruby on Rails Code on production server with Passenger and Apache?

In this blog, you are going to learn about the deployment of rails application on the production server with its configuration setting in Apache. For this, you need to have Ruby, Rails, MySQL installed in your server system.

Let’s begin with the process of deploying the Rails application.

Step 1: Add the code copy to the server.

         For adding code to the server, you need to take a copy of the code on your server by login using sftp.

$ sftp user@yourserver.com

$ put samplecode

Stpe 2: Installation of project and configuration settings.

         Install all libraries of the project and make configuration settings including configuration of database.yml and secrets.yml by using following commands. For this, you need to login to the server using ssh and go to the project folder.

$ ssh user@yourserver.com

$ cd samplecode

         Rails app has ruby versions and you have to use that specific version to run the application. So, use the ruby version of the application.

$ rvm use (ruby version)

         Install all libraries of the project, set the database and compile assets. Rails have some specific commands to do that.

$ bundle install

$ rake db:create RAILS_ENV=production

$ rake db:migrate RAILS_ENV=production

$ rake assets:precompile RAILS_ENV=production

         Rails provide a secret key which you have to mention it into the config/secret.yml file of the application to maintain the security.

$ rake secret

Above cammand provide a secret key, add it to theconfig/secrets.yml file of you RoR project.

Step 3: Apache settings

         You have to do apache settings to run the application in production mode on apache server. For this first, you have to createsamplecode.conf file in etc/apache2/sites-available/ path.

The file content will look like as in Image 1. Where you have to mention the domain of your application like www.myapp.com and server name like myapp.com. With this, you also have to mention the path of a public folder of the application and ruby version of the application.

Image 1: Samplecode.conf File

You need to create the symlink of the file samplecode.conf to the sites-enabled folder.  It is created for apache and virtual host settings. This virtual host setting will tell Apache where your application is located. Replace myapp.com with your application name and as well as mention path to ruby with the ruby version of the application into the samplecode.conf file.

         If you start the application on some port and not on some domain like www.myapp.com, you need to specify the port number in the conf file in place of port “80” at the top of the file. And then mention that port to the ports.conf file which is located at /etc/apache/ports.conf.

Image 2: Ports.conf File

In the above image, you can see how to mention port, like I have mentioned port 3000 to be heard by apache while serving the page. At last restart the apache server by using the following command. It will run the application on the link like 127.0.0.0:3000 or if it is for a domain then it will run on www.myapp.com or myapp.com.

$ sudo restart apache2 restart

In this way, you can start a rails app on the production server.

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Six rules to make Ruby On Rails code Crisp, Absolute and Clear!

In my coding lifetime, I have enhanced and improved my coding style after client feedback and guidance. I have learned over the years of time, that there aspects and points that has utmost importance in the coding of Ruby on Rails (RoR) application.

We as developers start writing code without actually analyzing and understanding the code requirement as well. A messed up code is no one’s favorite and not to be delivered.

I am sharing my thumb rules that will surely help you as it did to me.

Rule No. 1: Indent your code

What if you are given a much messed up code to update? I am sure you will get frustrated; in order to write very clear code keep it well indented. In Ruby on rails, though the auto-generated code is four space indented style we should use two spaces to intend our block of code as this is most widely adapted style. This improves the readability of our code.

Rule No. 2: Name it well!

Naming convention should be followed as this is helpful for us to understand the purpose of it and at certain places, active record in ruby also works on the basis of names.

Active record uses the same naming convention in order to find out how the mapping between the models and database tables are created.

Say for example a class “Category”, should have a database table called “Categories”. The rails pluralization mechanism is very powerful such that it is capable of pluralizing both regular and irregular words.

When it comes to naming a variable, you should follow CamelCase form, which says that the first word should start with a small letter and the next word should start with a capital letter, e.g. “categoryOne”.

When the table name has two words, it should be separated by “_” , e.g. “book_categoryies”. When it comes to model class, it should be singular with the first letter of each word capitalization e.g. “CategoryBook”.

Similarly, the name of methods should be such that it should define the purpose of that method, for e.g. “category_list”.

Rule No. 3: Less If else, Less complex

If else statement is a block of condition where you check the condition if it is true or false.

Using the number of if-else statement creates makes the code bulky. It will increase the number of lines in the code, which can be reduced or should not be used at all. It also makes the code complex and not easy to understand.

Rule No. 4: Use of a number of variables

What do variables do in rails? It allocates the memory for which it is assigned for. When the expression can be directly assigned or can be directly passed, a variable should not be used as this will be the unnecessary allocation of memory, unnecessary declaration of a variable.

In Ruby on rails, we have four different types of variables global variables, class variables, instance variable and local variables.

Global variables are accessible globally in the application which means it can be modified from any part of the program hence it let to lack of security of our code.

Hence it is recommended not to use global variables.

Always try to replace instance variable with local variable as local variables are accessed locally which ensures the security of our code.

Rule No. 5: Put-up a comment there

Comments are the description written in the source code within the special character so that it should be ignored by the compiler.

What if, you get a new project with some classes having methods in it? Will you be able to understand the purpose of it?

Even, if the method name is good enough? No, sometimes only method names do not help in recognizing or understanding the main purpose of the method or how it works, hence your method should be well commented in order to let others also understand its basic purpose.

Rule No. 6: Don’t put too much logic in the view, make use of helpers, create them!

Views are specially meant for displaying the data hence it should not have too much logic, this can be done by making use of helpers, if the piece of code is used many times in a view, make a helper and call it in a view.

So, these are my six thumb rules while writing code, from the time that I have become the developer. These have helped me and can be taken as consideration to make your code scalable, robust and secure.

This will add sparkle to your code, which will eventually make your client happy! :)

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The Beginners Guide for Getting Started with Automated Testing using RSpec and Selenium

Automated testing is extremely on the boom, across the board nowadays and obviously Ruby has its own arrangements to make it work for Ruby on Rails developers. One of these is RSpec, a madly prevalent tool for mechanized testing. The fortunate thing about it is we can test almost every part of RoR Application easily.

Rspec is easy to get it up and running, expressive way to write test cases, easy to use and also fast.

Let’s start with assembling all the components together to start with:

To begin it’s necessary to install Ruby. You can do it from here for Windows OS:  http://www.rubyinstaller.org

After completing installation let’s check if Ruby is installed properly along with version number.

For this go to command prompt and type:

                ruby -v

       You will get the following result.

Next, you need to install RSpec gem. Gem is Ruby library which can be used in one’s own code.

Go to command prompt and type the following :

      gem install rspec

      You will get the following output:

   Done installing documentation for diff-lcs, rspec-support, rspec-mocks, rspec-expectations, rspec-core, rspec after 22 seconds 6 gems installed

To start with Selenium in Ruby you also need to install the gem selenium-webdriver which will act as a binder for Ruby from the command line.

Type the following command to install ‘selenium-webdriver’:

gem install selenium-webdriver

Now, create directory i.e. folder to store Rspec scripts. Open your command prompt and change the directory path to the one where you would be saving your scripts.

Example: If your directory name is ‘sample_scripts’ on a desktop:

C:\Desktop\sample_scripts>

Let’s start with writing script in Rspec.

So for this open any editor. Here, I have used the sublime.

Write the following code in the sublime editor and save it. Save it with name sample.rb      

To run the script go to command prompt and type:

C:\Desktop\sample_scripts>rspec sample.rb You will get the output as following after executing the script:

Finished in 0.002 seconds (files took 0.11101 seconds to load)   1 example, 0 failures

Keywords in Rspec:

As this is targeted to new coders, you need to know some keywords which are meant to be used in your code. This helps in understanding the protocol to be followed while coding.

describe..... do

Description of the collection of related test cases

it......do

Individual test cases

Before() and After()

Optional test statements run before and after each or all test cases.

So, let’s hope you have understood the significance of using RSpec while automation testing.

This reduces your time to test & increases the efficiency of testing.

The code quality is needless to mention becomes high.

All these steps are for test-driven development (TDD) environment if you want to know how to use RSpec in Behaviour Driven Development (BDD) please refer our previous blog about it.

Aren’t we testers meant to have this as our focus? This is all about the beginning of using RSpec in your Ruby on Rails Development process.

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Software development team always share the code commit for the use of all members. GitHub is the best platform for this purpose.

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Easy steps to export HTML table data into Excel using jQuery. No plugins required.