Bootstrap Data to a Page

What does “bootstrapping” mean exactly? Hard-coding your data to the page using synchronous server-side template.

Most developers face the challenge of sending data from their server-side to the client-side to be used JavaScript. There are several solutions for this. Among the most common is creating an REST endpoint that can be consumed with asynchronous javascript, often using the jQuery Ajax function.

  • How is page load time affected when loading data asynchronously? Does the user’s experience depend directly on this data?
  • Is there unecessary overhead creating an REST endpoint?
  • Does the REST endpoint need to be secure? Authenticated? CSRF Tokenized?

Depending on the answers to these questions, bootstrapping may be an elegant solution for getting the data to the client-side quickly and with minimal development.

It typically looks something like this on the server side:

<script type="text/javascript">
//bootstrapped data with server-side template
var bootstrap = {
  "app_id": "",
  "session_id": "",
  "title": '',
  "price": "",
  "confirmation": ""

It looks like this when it’s rendered on the client side:

<script type="text/javascript">
//bootstrapped data rendered on client-side
var bootstrap = {
  "app_id": "a1b2c3",
  "session_id": "x0y9z8",
  "title": "My Cool App",
  "price": "1.99",
  "confirmation": "Thanks for purchasing our app."

This boostrapped JSON object can now be called with JavaScript immediately when the object is rendered by the browser:

// { "app_id": "a1b2c3", ... }

// My Cool App

Note: it’s best to put the bootstrapped object near the top of the page so it can used immediately, even before remaining html/css/javascript is loaded.

The key benefit of the bootstrapped object comes in the time saved when not having to use asynchronous JavaScript to call data from a REST endpoint. If you typically use jQuery Ajax to do this, 100-500 milliseconds of prerequsite load time would be added just to gain access to the jQuery.ajax() function. Any ajax request(s) retreiving data from a REST endpoint comes with additional load time expense.

If your app depends on this data, synchronously loaded (aka “bootstrapped”) JSON data will make your app snappy and your users happy. Not to mention, because of the server-side templating, REST endpoint security considerations are nullified.