Rails to JSON - Javascript

Rails is a web application framework written in Ruby that provides a structure for developing web applications. One of Rails' many features is its ability to convert Ruby objects into JSON (JavaScript Object Notation) format, which is a lightweight data interchange format that is easy for humans to read and write, and easy for machines to parse and generate.

In this article, we will be covering how to use Rails to convert Ruby objects to JSON, and how to consume this JSON in Javascript.

Object Serialization in Rails

Rails provides a built-in way to serialize objects to JSON through the as_json method. By default, calling as_json on an object will return a JSON representation of the object's attributes, which can be customized using options in the method call.

Here's a simple example:

class Book < ApplicationRecord
  def as_json(options = {})
    {
      id: id,
      title: title,
      author: author,
      published_at: published_at,
      created_at: created_at,
      updated_at: updated_at
    }
  end
end

In this example, we define a Book model with several attributes. When we call as_json on a Book object, it returns a JSON object with the same attributes as the Book object.

We can also customize the JSON output by passing options to the as_json method call. For example, if we only wanted to include the id and title attributes, we could call as_json(only: [:id, :title]).

Consuming Rails' JSON in Javascript

Once we have serialized our Ruby objects to JSON in Rails, we can consume this JSON in our Javascript code. In Javascript, we can parse JSON using the built-in JSON.parse() method.

Here's an example of how we might consume a list of serialized Book objects in Javascript:

// get the JSON data from the server
$.getJSON('/books.json', function(data) {

  // iterate over each book in the list
  $.each(data, function(index, bookJson) {
    // parse the JSON into a book object
    var book = JSON.parse(bookJson);

    // do something with the book object here
  });

});

In this example, we use the jQuery $.getJSON() method to retrieve a list of serialized Book objects from our Rails server. We then use the $.each() method to iterate over each object in the list, parsing the JSON into a Javascript object using JSON.parse().

Conclusion

Rails' built-in JSON serialization makes it easy to convert Ruby objects to JSON for consumption in Javascript. By following the examples in this article, you should now have a good understanding of how to serialize objects to JSON in Rails and how to consume this JSON in Javascript.