Archive for the ‘programming’ Category

Struggling between hiring an agency or a freelancer? Here is a solution!

Choosing between hiring a technology firm and a freelancer is undoubtedly one of the most confusing things. Everyone go through this struggle. The website is a reflection of a company. It defines their work, and give the visitor a rough idea about the company’s profile. One cannot put the company’s reputation at stake to save a few bucks. In this article, we will try to make your decision easier. There are few things you need to know about project & company before hiring.  Let us check out-

1. Know the scope of your project

Image result for scope of project The first thing you need to know is the scope of your project. Evaluate the needs & requirements of your project. Analyze the team requirement and size. You need to decide what kind of website you want to develop. If your project requires a large team, then a freelancer would not be a good choice for you.

2. Hire the right skill set

Image result for web developer vs web designer The right skill set refers to the difference between designing and development. It makes a huge difference. If you are uncertain about these things, you need to go back to the scope of the project, and then decide.
  • Web Designer: The designer develops the look and flow of the site. They work on HTML & CSS most of the time.
  • Web Developer: They are programmers who are primarily focused on coding, mechanics, and functionality of the website. They work on different frameworks and languages.
Now you can easily select which one do you want.

3. Look at their portfolio & experience

Image result for company portfolio Before jumping into an agreement or contract, you need to check out if they are reliable. Check their previous work, portfolio, website, etc. If you are planning to hire a freelancer, then you should check his/ her work profile on those websites.

4. Get to know them

Image result for teamwork Narrow down the candidates, and get to know more about them. Know more about their previous work, check out their reviews on different platforms. Good communication is critical, especially if you’re working with a remote team. Do they reply to your emails on time? Would it be possible for them to provide templates on time?

5. Hire!

Now, you have crossed all four steps, you are ready to hire the team! Image result for hire! You need to be careful while hiring someone for your work. There will be advantages and disadvantages, but you need to evaluate the pros and cons of both, and then make the decision.  

9 Things You Should Know About Ruby on Rails

There are many programming languages, different frameworks, and uncountable developers. But Ruby on Rails has become one of the most popular languages among the developers. Though most of the people start their programming career with languages like Java, C++, PHP, etc., Ruby on Rails is what startups and some full-fledged companies use while developing websites. Image result for ruby on rails The first question that crosses everyone’s mind after hearing ‘Ruby on Rails’ is ‘What is Ruby on Rails?’. In this article, we are going to discuss some important things about ‘Ruby on Rails’. Let us start-

1. What is Ruby on Rails? Is it one thing or Ruby and Rails are two different things?

To be specific, Ruby is a programming language, whereas Rails is a web application framework designed to work with Ruby. Ruby is simple to learn and is super fun. It is easier than other programming languages. But the only problem with Ruby was that it was not designed for use on the web until Rails came. Rails are the most popular framework for Ruby basically make it possible to write a Ruby application and have it be a website.

2. Is ‘Rails’ good for the beginners?

Before moving to ‘Rails’, the first thing you need to learn is Ruby. The reason behind ‘Rails’ being good for beginners is because Ruby is simple to learn. Ruby is easier because the language is super flexible and not always case sensitive. And Rails is fun for beginners because it is robust and it does so much of the hard work for you. The developers do not have to bang their heads to find a minute mistake in the whole code. Basically, the first you have to learn Ruby and then you will be able to learn Rails.

3. How is Rails developer different from Ruby programmer?

As mentioned above, you have to learn Ruby first because Rails is a framework. Technically, a good developer can easily on Ruby web apps using other web frameworks like Sinatra. But a developer would not be hired just to write Ruby, So, it is important for a Ruby developer to learn Rails for future.

4. How good should a developer be to get hired as Ruby on Rails professional? What makes Rails so special?

To be honest, it takes a lot of time to become a Ruby on Rails expert. Basically, you should be comfortable in working on Ruby. You cannot dive into Rails without learning Ruby, but it is important to learn Rails afterwards. It is just like learning to ride a bicycle before learning to ride a bike. Specifically, you need to know about all the basics including data types, object orientation, debugging, etc. And the thing that makes Rails so special is because of its rapid prototyping. You can develop a Rails app with few hours. There are few frameworks that could make it possible.

5. What could be built with it?

Well, the answer is you can build any web application with Rails. Some of the most popular website built on Ruby on Rails are Shopify, Airbnb, Bloomberg, SoundCloud, etc.

6. Is possible to build mobile apps with it?

This is a bit complicated. It is not possible to literally build a mobile app in Rails. But you can build a web application in Rails, and use it as the backend for a mobile app. There are other options like RubyMotion which makes it easy to build native iOS and Android apps using Ruby. Talking in a straightforward manner, you cannot literally use Rails in developing mobile apps, but it could be an important part of the project.

7. Shouldn’t I learn JavaScript instead?

Well, if you are asking instead, then the answer is no. And if you ask also, then the answer is yes. The reality is a Ruby on Rails developer to need to learn JavaScript one time or another. It is not a prerequisite skill but it will help in future for further progress. And if you are thinking about which one you should be learning first, then the answer is Ruby is easier to learn than JavaScript. JavaScript is the first preference of students, but in the end, you have to learn both.

8. How long would it take to learn?

A few months of dedicated study can make you comfortable with Ruby on Rails. But if you want to be a master, you have to give at least 10,000 hours. Your level of familiarity with different programming languages would have an impact on you being comfortable with Ruby on Rails.

9. How to get started with this?

If you are already familiar with programming languages, then it would be easy for you to learn Ruby on Rails. But if you don’t know even a single thing about coding, then first you need to learn HTML & CSS. And then you need to learn Ruby, Git & command line.
The most important thing you need to do while learning something is having a project by your side. It would help you to learn, and find out your weak spots. These are the most common questions that come to everyone’s mind. So, if you have any question, just comment below and we will try to answer it!

Kotlin- The Next-Gen Android App Development Language

Android app development is a major part of today’s technical and economical world. People use different languages for developing apps, though Java remains the most used language to develop logic. While running a Java application, the app is compiled into a set of instructions called Bytecode and runs in a virtual machine. In last few years, new programming languages have been introduced which also run on Java virtual machine. The reason behind using these languages is that the resulting app looks same for the virtual machine with simple code and some fixes that developers face while coding in Java. Image result for kotlin   Recently, one such language is introduced by JetBrains, known for IntelliJ IDEA (Android Studio is based on IntelliJ), called Kotlin. It is a statically typed programming language that runs on the JVM. It can be compiled to JavaScript source code. It has many other amazing features, and we will be knowing about them in this article.

Why Kotlin instead of any other language?

Since Java is the only language most of the people use while developing the mobile apps, developers had no actual alternatives to Java app. Java comes with a lot of historical baggage and some issues. Java 8 solved some of those problems, and some were corrected in Java 10. But these two options also have loopholes. One of them is in order to use these two versions, one must have the minimum SDK to Android 24 to use Java 8 which is not an option for many developers. And Java 10 is even far from their reach. So, Kotlin was made to fill these gaps through model language. There are some core principles that Kotlin work with-
  1. Concise- Reduce amount of boilerplate code
  2. Safe- Avoid entire classes of error such as null pointer
  3. Smart- Make your code more readable and understandable
  4. Tool-friendly- One can choose any Java IDE or build from the command line
  5. Interoperable- Leverage existing frameworks and libraries of JVM, Android, and browser.

How to work on Kotlin?

Download the starter project. Extract and open the starter project in Android Studio. It is a simple app that allows users to search for books, book covers and share books with friends to explore Kotlin. Image result for kotlin vs java

It consist of three source code files, let us check it out-

MainActivity.java- an activity that displays the screen for searching and displaying a list of books. DetailActivity.java- an Activity that displays the book cover for the ID passed to it. JSONAdapter.java- a custom BaseAdapter that transforms a JSON object into a listview item. Build and run the project to see what you’re working with.

How to set up the environment of Kotlin?

Android Studio doesn’t have any idea of what to do with Kotlin. So the first thing you need to do is to install the Kotlin plugin and configure Kotlin in your project.

-Installing the Plugin

1. Go to Android Studio/ Preferences and Select the Plugins entry. kotlin for android 32. Click on Install JetBrains plugin on Plugins screen intro_to_kotlin_4 3. Search and select Kotlin from the list and click Install. intro_to_kotlin_5 4. When you are done with downloading and installing Kotlin, then you need to follow the prompts to restart the IDE. intro_to_kotlin_28

– Configure Kotlin in Project

Now the IDE knows what to do with Kotline, but your project app doesn’t, so you have to modify the project’s build configuration. How do modify the project’s build configuration? Let us check out- 1. Go to Tools-> Kotlin-> Configure Koltin in Project intro_to_kotlin_7 2. A Choose Configurator pop up will appear, select Android with Gradle from the drop down. intro_to_kotlin_8 3. On Configure Kotlin in Project popup, select the plugin version you want to use and click OK. Configure Kotlin in Project 4. These actions will make some changes to your build.gradle files.   build.gradle (Project: omg-android-starter): buildscript {  ext.kotlin_version = ‘1.0.3’ // 1  repositories {    jcenter()  }  dependencies {    classpath ‘com.android.tools.build:gradle:2.1.3′    classpath “org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version // 2    // NOTE: Do not place your application dependencies here; they belong    // in the individual module build.gradle files  } } allprojects {  repositories {    jcenter()  } } build.gradle (Module: OMG Android):    apply plugin: ‘com.android.application’ apply plugin: ‘kotlin-android’ // 3 android {    compileSdkVersion 23    buildToolsVersion “24.0.2”    defaultConfig {        minSdkVersion 14        targetSdkVersion 23    }  sourceSets {    main.java.srcDirs += ‘src/main/kotlin’ // 4  } } dependencies {  compile ‘com.android.support:appcompat-v7:23.2.0′  compile ‘com.loopj.android:android-async-http:1.4.4′  compile ‘com.squareup.picasso:picasso:2.1.1′  compile “org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version // 5 } repositories {  mavenCentral() }   Here is a summary of what this code is about-  
  1. Declares configured Kotlin version
  2. Declares classpath dependency artifact that contains the Kotlin Gradle plugin with the version declared earlier
  3. Specifies the use of Kotlin Android plugin via apply plugin command
  4. Defines that source files found in src/main/Kotlin will be compiled. Gradle will compile source Kotlin files found in src/main/java.
  5. Added the Kotlin Standard library as a compile-time dependency to the project.
    Click on Sync Now to build a project and run it! intro_to_kotlin_25 Nothing changed visually here, it just made your work bit easier!

Here are 10 reason why Kotlin is cool-

Image result for kotlin
  1. Kotlin is open source
  2. Full Java Interoperability
  3. Kotlin compiles to JVM bytecode or JS
  4. Data Classes in Kotlin
  5. Defaulted parameters
  6. Kotlin imposes no runtime overhead
  7. Null Safety in Kotlin
  8. Extension functions
  9. Swift is like Kotlin
  10. Kotlin wants you to write less code
Inputs & Source

Ruby on Rails vs Java Enterprise, Which one is Better?

Which is the best framework for your website? Have you ever given this thing a thought? Well, there are many languages which helps to design the framework for a website. There is Ruby on Rails, JEE, ASP.NET, Django and much more. But there are few languages that most of the programmers prefer.

Source: schlitt.info

ASP.NET is a Microsoft platform which takes it straight to the risk zone. You cannot risk being locked into a Microsoft platform whereas other platforms are niche. So everything comes down to Java Enterprise (JEE) and Ruby on Rails (RoR).

Here are some differences through which you can figure out which one is better for your website:

#1 The focus of Ruby on Rails is on fast and agile development whereas Java Enterprise focus on flexibility and integration with enterprise IT. #2 The common tasks in RoR are made very simple as compared to JEE. In JEE, even the simplest jobs need extraordinary efforts like to write XML configuration or auto-generate boilerplate code. #3 RoR is used by start-up employees; JEE is used in the IT nerve-centres of investment banks. Image result for java vs ruby on rails #4 As a developer, RoR is pretty easy to learn, while the main problem a newcomer faces in JEE is to choose between huge number of different libraries and different ways to do the same thing. There is no particular libraries which are widely used. #5 There are few people who work on Ruby on Rails, while every computer science student learns Java. #6 In manageability of the code, JEE is better as it is easier to find out the things. Image result for java vs ruby on rails #7 Fortunately, both frameworks offer reasonable support for automated regression testing; Ruby on Rails probably a bit more so, because it relies primarily on automated tests (rather than a type system) to ensure things don’t fall apart horribly.  

There are many aspects on which you can compare these two. Now the choice is yours. What do you think, which one would be the best for you? Tell us in comments!


Single Sign-On In Rails Application

Single sign-on (SSO) is a property of access control of multiple related, but independent software systems. With this property a user logs in once and gains access to all systems without being prompted to log in again at each of them. Such as we once log in to google, we are permitted to access the Youtube, Docs, Google Drive etc. dnd1999110501 We may think about sharing the session cookies among the all domains but its generally not a good idea. One can steal cookies to sign in from other system or browser. Single SignOn Helps us in getting around this problem and implement a much robust system. How do we implement Single Sign-On in Rails App? We will try to get our hand around on how to build a prototype around a rails app to implement single sign-on. We will be looking a sample rails application powered by CASino gem Why we are using CASino ?
  1. Distributed under MIT LIcense
  2. Active Development since
  3. External authentication sources (LDAP, SQL)
  4. Two-factor authentication
  5. Session-overview for logged-in users
  6. Full localization support
  7. REST-API
So what is CASino exactly? CASino is a simple Single sign-on server application. It supports the CAS protocol and can therefore be used in combination with almost every web programming language out there. CAS is an authentication system originally created by Yale University to provide a trusted way for an application to authenticate a user. CAS centralizes authentication: It allows all your applications to ask users to login to a single sign-on server The implementation. Here we have two apps client and server. We assume that the app is using devise for the demonstration purposes. The Logic can easily be extended to other authentication methods though. The app is as simple as configuring a few variables in the CASino gem.
  1. user request to client domain .
  2. it redirects to the server if not authorised.
  3. Start with adding the gems client app
  4. redirects to back url to whichever client request url is
Step #1 Implementing the client application. Gemfile # If You face some compatability issues then use ruby 2.1

gem 'devise_cas_authenticatable', git: '<a href="https://github.com/jpamaya/devise_cas_authenticatable">https://github.com/jpamaya/devise_cas_authenticatable</a>'

routes.rb

devise_for :users, skip: [:sessions], controllers: { cas_sessions: 'sso_cas' }

devise_scope :user do

get "sign_in", to: "devise/cas_sessions#new"

delete "sign_out", to: "devise/cas_sessions#destroy"

end

devise.rb # ==> Configuration for SSO server authentication

config.cas_base_url = "http://localhost:4000/"

config.cas_create_user = false

config.cas_destination_logout_param_name = 'service'

config.cas_enable_single_sign_out = true

User.rb

devise :cas_authenticatable

Now run client application on localhost:3000 and begin with typing users/sign_in Since we overwrote devise’s sign in mechanism, so instead of presenting devise’s normal sign in page, we are redirected to localhost:4000 which is the backend app to authenticate the users. Lets prepare the backend app to authenticate the users.  Step #2 Start with implementing code in server app limitation use ruby ruby “2.1.5” and rails “3.2.11” check rails -v ‘~>(‘ 3.2.11′). for server app Gemfile #It users these db to store sessions and some tokens. casino will take care all about these

gem 'sqlite3'   # for sqlite support

gem 'mysql2'    # for mysql support

gem 'pg'        # for postgresql support

gem 'casino'

Run bundle install and rails g casino:install The CAS configuration is stored under config/cas.yml. This is where you configure how your SSO handles logins. An example configuration can be found in the file config/cas.yml.example provide the valid db credentials and run the migrations. Run this app on localhost:4000 , Just follow the old steps
  1. Goto localhost:3000/users/sign_in
  2. You will redirected to localhost:4000 enter credentials click sign in
  3. You will be redirected back on successful login
In the links below you can find some ready made examples for you to clone these  apps and have better understanding of SSO.
Server exampleruby “2.1.5”git clone https://github.com/codescrum/casino-sso-server-example.gitRails 4 client examplegit clone https://github.com/codescrum/casino-sso-client-rails4-example.gitRails 3 client example git clone https://github.com/codescrum/casino-sso-client-rails3-example.git
Let us know in comments if you face any troubles in the implementation !! PS: Single Sign-out has been left as a thought for another day and we will discuss that in a follow up blog.

The technology stack powering the on demand applications

Uber and Ola have given rise to a slew of Ondemand applications which claim themselves to be Uber/Ola of X. Some of the verticals where these applications have found their usability include but not limited to taxi, transportation, Logistics, Home Services, Health apps and so on. In this blog we will go deeper into the various components and technology involved in on Demand Apps. Components Involved in Building and On Demand App In most of the cases there are 3 components involved in building an On-Demand App:
  • A cloud backend for Data Interaction APIs and live dispatch of Jobs
  • An Android/iOS App user to make a job(e.g book a ride with Uber/Ola)
  • An app with the drivers to receive the jobs created by the users and attend to them.
  Lets analyze each of these components in detail and how one can go around building each of them. Web Backend Web Backend is the most critical part of the On Demand applications because backend is what powers both the consumer and the driver apps. The web backend must meet the following requirements for a successful implementation:
  • A Light footprint to dispatch the jobs on fly.
  • A Good dispatch components to maximize the efficiency of the field workers(drivers in case of uber).
  • A Socket connectivity to enable the jobs dispatch and job information to the user.
  • A Good structure for a flexible and structured development
  We have recently worked on Bodhik which is an Ondemand Application for Financial Advisory Services.

jQuery Validate

jQuery Validation plugin is popular and simple plugin for client side validations. It can be customized with plenty of options. It can be easily integrated into your existing forms. The plugin already has set of useful validation methods including URL and email validation that come out of the box. The plugin provides an API to write your own methods. All in built methods comes with default error messages in english. In the blog, I will try to explore a few methods and usage of jQuery Validate Plugin. Plugin Methods This library adds three jQuery plugin methods:
  • validate() – Validates the selected form.
  • valid() – Checks whether the selected form or selected elements are valid.
  •  rules() – Read, add and remove rules for an element
Setting up: You need to download the files and then place dist/jquery.validate.min.js file in #= require jquery.validate.min Applying to the form:
  • You just need to add a class ‘jqvalidate’ to the form that you want to validate. In rails, you will generally do it like following
    <%=  form_for(@account, :html =&gt; { :class =&gt; "jqvalidate" }) do |f| %>
    .........
    .........
    <% end %>
    
  • Next you need to create a function that is to be called before the form is loaded:
    $.validate_form = () -&gt;
    $.validator.addClassRules({
    cc_number: { required: true, digits: true, minlength: 15, maxlength: 16},
    cc_cvv: { required: true, digits: true, minlength: 3, maxlength: 4}
    })
    $('.jqvalidate').validate({
    ignore: ".jqvalidate_ignore"
    errorClass: "invalid"
    })
    
  1. addClassRules is used to specify validations on the fields with its in built methods. cc_number and cc_cvv are the classes given to two different fields respectively on which the validations are applied.
  2. ‘.jqvalidate_validate’ class is given to those fields that are not subject to the validations by this plugin.
  3. ‘invalid’ is the class given to the error messages.
The blog post just details the start for the plugin. We encourage you to dig more and explore this great plugin. For more details, refer to the documentation.

Capybara Basics For Automated testing of Ruby on Rails Application

Automated Testing is an integral part of large scale production Ruby on Rails applications. A solid Integration test suite ensures that the integration between various components of the application is smooth and seamless. An integration test generally spans multiple controllers and actions, tying them all together to ensure they work together as expected. It tests more completely than either unit or functional tests do, exercising the entire stack, from the dispatcher to the database. Capybara comes in handy in simulating the testing in real user environment. In this blog we will explore various ways by which we can strengthen our apps with Capybara.

    • Capybara is an integration testing tool for rack based web applications. It simulates how a user would interact with a website.
    • Capybara helps in testing your web application as a real user would do. It is independent of the driver that is running your tests and comes with Rack::Test and Selenium support built in. For other drivers, you need to include their respective gem.
Capybara requires Ruby 1.9.3 or later and can be installed as a gem by listing in your gem file and then installing bundle or it may be installed directly by typing:
gem install capybara
  • Include capybara in your helper file:
    require 'capybara/rails'
Using Capybara with Rspec
Integrating capybara with rspec is fairly simple. Lets go through a step by step process to understand the integration. The following test simulates a login in a real user environment.
  • Include capybara’s rspec directory
    require 'capybara/rspec'
  • Capybara specs are required to be placed in spec/features
  • Here is a simple test to test the login page working.
    describe "Login" do
    before :each do
    user = User.create(:email =&gt; 'RoR@enbake.com'”,:password =&gt; 'password')
    end
    it "logs the user in" do
    visit login_path
    fill_in "Email", with: user.email
    fill_in "Password", with: 'kanwal_enbake'
    click_button "Sign in"
    page.should have_content "success"
    end
    end
    
    The test source code is fairly simple to understand and implement so I will not be going into the details here.
Testing Javascript with Capybara
  • By default Capybara uses the :rack_test driver, which is fast but limited as it does not support JavaScript. So you need to switch to Capybara.javascript_driver(:selenium by default) by using :js => true. For instance: describe “example of testing js”, :js => true do it “tests js with default js driver” do end it “tests js with one specific driver” , :driver => :webkit do end end
  • To make Capybara available in all test cases deriving fromActionDispatch::IntegrationTest : describe ActionDispatch::IntegrationTest include Capybara::DSL end
Drivers
  • You may sometimes, want to switch default driver and want to run everything in selenium, you could do:Capybara.default_driver = :selenium
  • In any case – provided you are using Rspec or Cucumber – if you want use faster :rack_test as your default_driver, and use JavaScript-capable driver only for selective test cases, you can use :js => true for Rspec and @javascript for Cucumber. By default, JavaScript tests are run using the :selenium driver. You can change this setting by Capybara.javascript_driver.
  • You can also, particularly in before or after blocks, change driver temporarily: Capybara.current_driver = :webkit
  • Capybara.use_default_driver would switch back to default driver
Note: switching the driver creates a new session, so you may not be able to switch in the middle of a test.
Techniques and Trivial Testing Tasks
Navigating
  • visit(‘/projects’)
  • visit(post_comments_path(post))
Clicking links and buttons
  • click_link(‘id-of-link’)
  • click_link(‘Link Text’)
  • click_button(‘Save’)
  • click(‘Link Text’) # Click either a link or a button
  • click(‘Button Value’)
Interacting with forms
  • fill_in(‘First Name’, :with => ‘John’)
  • fill_in(‘Password’, :with => ‘Seekrit’)
  • fill_in(‘Description’, :with => ‘Really Long Text…’)
  • choose(‘A Radio Button’)
  • check(‘A Checkbox’)
  • uncheck(‘A Checkbox’)
  • attach_file(‘Image’, ‘/path/to/image.jpg’)
  • select(‘Option’, :from => ‘Select Box’)
Scoping
  • within(“//li[@id=’employee’]”) do fill_in ‘Name’, :with => ‘Jimmy’ end
  • within(:css, “li#employee”) do fill_in ‘Name’, :with => ‘Jimmy’ end
  • within_fieldset(‘Employee’) do fill_in ‘Name’, :with => ‘Jimmy’ end
  • within_table(‘Employee’) do fill_in ‘Name’, :with => ‘Jimmy’ end
Querying
  • page.has_xpath?(‘//table/tr’)
  • page.has_css?(‘table tr.foo’)
  • page.has_content?(‘foo’)
  • page.should have_xpath(‘//table/tr’)
  • page.should have_css(‘table tr.foo’)
  • page.should have_content(‘foo’)
  • page.should have_no_content(‘foo’)
  • find_field(‘First Name’).value
  • find_link(‘Hello’).visible?
  • find_button(‘Send’).click
  • find(‘//table/tr’).click
  • locate(“//*[@id=’overlay'”).find(“//h1″).click
  • all(‘a’).each { |a| a[:href] }
  • current_path.should == post_comments_path(post)
Scripting
    • result = page.evaluate_script(‘4 + 4′)
    • page.execute_script(“$(‘#id_of_anything’)”).click
Note: unlike page.evaluate_script, page.execute_script do not return anything. You have to explicitly perform action to make it return a value Debugging
  • save_and_open_page
  • page.save_screenshot(‘screenshot.png’) *driver specfic
Asynchronous JavaScript
  • click_link(‘foo’)
  • click_link(‘bar’)
  • page.should have_content(‘baz’)
  • page.should_not have_xpath(‘//a’)
  • page.should have_no_xpath(‘//a’)
XPath and CSS
  • within(:css, ‘ul li’) { … }
  • find(:css, ‘ul li’).text
  • locate(:css, ‘input#name’).value
  • Capybara.default_selector = :css
  • within(‘ul li’) { … }
  • find(‘ul li’).text
  • locate(‘input#name’).value
Calling remote servers
  • Normally Capybara expects to be testing an in-process Rack application, but you can also use it to talk to a web server running anywhere on the internet, by setting app_host: Capybara.current_driver = :selenium Capybara.app_host =https://www.google.com
I hope the blog gives a good introduction of adding capybara tests to your rails apps. Its just the tip of the iceberg and the possibilities are endless. Lets make our apps more robust and flexible .. :).

Embedly Integration in Rails

Embedly is a powerful tool to embed multimedia content or images or even blogs in your application. It comes in handy especially to make your content easier to share.
Embedly provides an easy to use official ruby gem to integrate Embedly into your RoR app. The usage of the gem is fairly straight forward. I will try to go step by step on how to integrate embedly API into an RoR app.
  • Add the gem in your gem file
    gem "embedly"
    Bundle the Gems
  • Get the API key from “https://app.embed.ly/login”. For the purpose of the blog we assume that the API key is accessible through the config variable AppConfig.embedly[:api_key]
  • Mostly the embeds will stay the view side logic so lets create a small helper to generate an embed from a Youtube Video. The call to the API is pretty straight forward and intuitive as we can see from the following code.
  • require 'embedly'
    require 'json'def display
    embedly_api =Embedly::API.new AppConfig.embedly[:api_key]
    obj = embedly_api.oembed :url => 'http://www.youtube.com/watch?v=sPbJ4Z5D-n4&feature=topvideos'
    obj.first.html
    end
  • The code calls the embedly API to generate an ombed for the youtube url and returns the html for the embed. This html can be used directly to embed the content into your blog or app.
  • Thats it !!

Enjoy supercharged content with your app and feel free to post any comments in the comments section.

A Step by Step Guide to Setup Rails application on Ec2 instance (Ubuntu Server)

Sometimes the Bitnami or other Rails AMIs doesn’t fit your needs directly and you will feel the need of building the Server yourself.Here I go step by step in building such a stack on top of Amaon EC2 Ubuntu Server.
  • Rails applications are a little bit different to install on servers but the process is very easy.Rails application needs a web server and an application server to run with. For development, it comes with default Webrick server that serve as application server on local machine. For setting it up on production server, we have the following choices on Web and application servers :-

    • Web servers

      1. Apache

      2. Nginx

    • Application Servers

      1. Passenger

      2. Thin

      3. Puma

      4. Unicorn

  • The simplest and best combination consists of Nginx + Passenger. It allows greater flexibility for configuration and also allows good speed over other combinations. So we are going to setup an Rails application using Nginx + passenger configuration on a bare Ubuntu server. Here are the steps :-

  1. Launch an Ec2 instance with ubuntu AMI. Make sure you have HTTP and SSH access to the server.

  2. SSH into the server by using private key (.pem) used while launching the instance and install the available updates by running :-

    sudo apt-get install updates
  3. Now you need to setup ruby on your server, so install the single user rvm ruby by following this blog.
  4. Load the rvm and make the installed ruby as default by running the following commands :-

    source ~/.rvm/scripts/rvm
    rvm use 2.1.0 –default
  5. Install the version control to clone your rails application to server. We generally use Git with rails application which can be installed by running the following command :-

    sudo apt-get install git
  6. Now clone your application on the server :-

    git clone yourepo.git

    Note:- In case of private git repository, you need to add public key of server to deploy keys of your repository, otherwise you will be promped with an permission denied error.

    OR

    Deploy using application to this server using Capistrano script. Please read this blog for more details on deploying your application using Capistrano.

  7. Now go to your application and install the gems by running bundle install command. If you want to setup your database on the same server, you can do the same by using the following commands 😐

    • In case of MYSQL

      sudo apt-get install mysql-server mysql-client
      sudo apt-get install libmysql++-dev
    • In case of POSTGRESQL, follow this blog for installation and then install the development headers

      sudo apt-get install libpq-dev

      After setting this up, migrate your databases in whichever environment you want to launch the server.

  8. Now install the Passenger gem by running :-

    gem install passenger

  9. Next step is to install the Nginx server, but we have some pre-requisits for this.

      1. It needs curl development headers which can be installed by :-

        sudo apt-get install libcurl4-openssl-dev

      2. It will be installed under /opt directory and your user should have permissions to that folder, so make your user as user owner for /opt directory by :-

        sudo chown -R ubuntu /opt

  10. Now install the Nginx server with passenger extension by running the following command :-

    passenger-install-nginx-module

  11. Set your Nginx server as service in init script by using the following commands :-

    wget -O init-deb.sh http://library.linode.com/assets/660-init-deb.sh
    sudo mv init-deb.sh /etc/init.d/nginx
    sudo chmod  +x /etc/init.d/nginx
    sudo /usr/sbin/update-rc.d -f nginx defaults
  12. Setup your application path in the nginx configuration file i.e. /opt/nginx/conf/nginx.conf.

    server {

    listen 80;

    server_name localhost;

    root /home/ubuntu/my_application/public #<-- be sure to point to 'public'

    passenger_enabled on;

    rails_env production;

    }

  13. Lastly start your server by running the following command :-

    sudo service nginx start