Exploring JavaScript functions within the Rails 4 asset pipeline directory

Question

Exploring JavaScript functions within the Rails 4 asset pipeline directory

I am facing an issue while trying to use a JavaScript function through the Chrome Console after embedding that function within the Rails Asset Pipeline Manifest. To achieve this, I followed these steps to create and set up a basic Rails 4.2.4 App:

$ rails new JavascriptExample
$ cd JavascriptExample
$ rails g scaffold Bear name:string
$ rake db:migrate

Next, I made changes in the

app/assets/javascripts/bears.coffee

file by adding a console log statement and defining a function as shown below:

console.log("asset pipeline sucks")
square = (x) -> x * x

After making these changes, I started the server using the following command:

$ rails s

Upon visiting localhost:3000/bears, I noticed that my console log statement worked fine. However, when I tried running the square(5); command in the console, it threw an error stating

Uncaught ReferenceError: square is not defined(…)

.

My question is, why am I unable to execute the function in this manner even though it is clearly loaded into application.js?

javascript ruby-on-rails asset-pipeline

Answer 1

Answer №1

Your CoffeeScript code has been transformed into JavaScript:

(function() {
  var square;

  console.log("asset pipeline sucks");

  square = function(x) {
    return x * x;
  };
}).call(this);

Referencing this:

In CoffeeScript, the var keyword is not used and could lead to syntax errors. Local variables are created implicitly by default.

, thus they are not available in global scope as anticipated

To correct this issue, you can modify your code like so:

console.log("asset pipeline sucks")
@square = (x) -> x * x

Take note of the use of @ symbol. After compilation, the JavaScript code will look like this:

(function() {
  console.log("asset pipeline sucks");

  this.square = function(x) {
    return x * x;
  };

}).call(this);

Answer 2

Your CoffeeScript code has been transformed into JavaScript:

(function() {
  var square;

  console.log("asset pipeline sucks");

  square = function(x) {
    return x * x;
  };
}).call(this);

Referencing this:

In CoffeeScript, the var keyword is not used and could lead to syntax errors. Local variables are created implicitly by default.

, thus they are not available in global scope as anticipated

To correct this issue, you can modify your code like so:

console.log("asset pipeline sucks")
@square = (x) -> x * x

Take note of the use of @ symbol. After compilation, the JavaScript code will look like this:

(function() {
  console.log("asset pipeline sucks");

  this.square = function(x) {
    return x * x;
  };

}).call(this);

Exploring JavaScript functions within the Rails 4 asset pipeline directory

Answer №1

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