NodeJS How to use a property to set another property in module.exports?

Question

NodeJS How to use a property to set another property in module.exports?

module.exports.views = {
  theme: 'themes/theme1/',
  layout: this.theme + 'layout'
};

I want the layout property to depend on the theme property. However, when run, the layout property seems to be undefined. What did I do wrong? Please help...

node.js

Answer 1

When you run the code this.theme + 'layout', this does not refers to your views object but it refers to the global object, which as no theme property.

This should work:

var view = {};
view.theme = 'themes/theme1/';
view.layout = view.theme + 'layout';

module.exports.views = view;

Answer 2

It's not possible to refer to the object being created via object literal notation from within the notation itself. At the moment, this refers to the window, or global in node.js's case.

You will need to return the value with a getter function.

module.exports.views = {
    theme: 'themes/theme1/',
    layout: function() {
        return this.theme + 'layout';
    }
};

Or you can turn it into a constructor.

module.exports.views = function() {
    this.theme = 'themes/theme1/';
    this.layout = this.theme + 'layout';
};