Authorization with Pundit gem


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Security is an important aspect of application development. Two main components of security are Authentication (Who are you?) and Authorization (are you supposed to be here?). Authentication verifies the user’s identity while authorization verifies whether that user has access rights on certain resources to perform actions on them.

Two popular gems for authorization in the rails world are CanCanCan and Pundit, we at Red Panthers prefers pundit over CanCanCan we get to write Pure Ruby Objects and keep the logic for each part separate.

The gem CanCanCan isolates (encourages) all authorization logic into a single class. It is a drawback when the complexity of application increases. Pundit gem provides object oriented design patterns to build our own authorization system that meets project’s requirements. It enables us to keep the models and controllers free from authorization code and allows to keep the resource logic separately. This flexibility and simplicity of Pundit gem help to use it with ease.

To start with Pundit

Add Pundit gem to your gem file and run bundle install.

Integrate Pundit to Rails application by adding the following line to ApplicationController.

If you run the Pundit’s generator as below, it will generate app/policies folder which contains …

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Taking screenshots of webpages using Ruby


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Recently we have been working on taking screenshots for web page while generating reports based on that website. During this endeavor, we came across some tools to achieve that. We are sharing the information we gathered here.

The tools that we will discuss for screencapture, in  Ruby,  are:

  • PhantomJS
  • Screencap gem
  • Webshot gem

Screencap and webshot are gems in Ruby that depends on a tool called PhantomJS. It is basically a web browser without a user interface, primarily used for testing websites. Such type of browsers are generally referred to as headless browsers,

Screenshots with PhantomJS

PhantomJS is quite easy to install and is multiplatform, available on major operating systems.

To start, our script must require a reference to the webpage module then use it to create an instance:

Use the instance.open() method and pass it the arguments, the url of the webpage that we want to capture screenshot.

instance.render() method captures the screenshot and saves it to the file specified in the argument.
Run the script as,

Screenshot is saved in the  directory where we run the script.

Now what we have above is all JavaScript, but to use the phantom JS in our rails application we have gems that provide us with an easy interface to acheive the …

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