Single Page Applications: Everything You Need to Know

by Jan Schulte, Head of Group Consulting at Magnolia
Jul 5, 2019 | 4 MIN

Traditionally, whenever a user clicked on a link within a web page, the browser would send a request to the server for a new page. When the server received the request, it would send the new page to the user’s browser. This is a slow and tedious process, often placing a heavy load on the servers for popular sites because the data for an entire webpage is sent on every click.

Single Page Applications (SPAs), however, are changing the game. Many of today’s high-traffic sites and social media platforms are adopting SPAs, which allow all information to be loaded on a single page, rather than being loaded as separate pages.

What are Single Page Applications?

A single page application (SPA) is a web-based app that pre-loads within the browser. In doing so, the SPA removes the need for constant reloading of the full webpage, and it only dynamically reloads the relevant content for each user interaction. This results in a user experience that is faster when transitioning between different navigational sections.

Many of the top websites function as SPAs including several of Google’s tools like Gmail, Google Maps, and Google Drive. And social media giants, including Facebook and Twitter, are also built as SPAs. Since the functionality of SPAs is handled within the browser, this type of application is always made using frontend frameworks like React, Angular, Vue, Ember.js, Meteor.js, or Knockout.js.

Benefits of Single Page Applications

As the brains behind many of the world’s top web sites can attest, SPAs have numerous benefits for both users and developers. Some of these advantages include:

Faster User Experience: Since users no longer have to wait for responses from the server every time they click a navigational link, users can get the information they want much faster. As all of the necessary client-side structure for the site is already in place, once the SPA loads the server responses only need to include the data to fill in the gaps.

Fewer Server Resources: The SPA loads within the browser one time. When a user makes a request, the server returns the data requested in a format like JSON, rather than the entire page's HTML markup each time. This means that SPAs save on bandwidth and server resources, which is one of the reasons why sites that get millions of views a day rely on SPAs for efficiency and reliability.

Easier to Debug: Instead of reading through thousands of lines of server-side code, developers can debug SPAs by examining the JavaScript code rendered in the browser. Many of the JavaScript frameworks that power SPAs have their own debugging tools available for the Chrome browser. These tools can show developers how the page elements are displayed, how the page requests data from the server, and how the page caches data.

Easier Transition to Other Apps: Developers can use much of the same code to transition from an SPA to a mobile app. Since all the content gets delivered at once, SPAs are highly suited for scrolling, which makes them the ideal starting point for mobile apps. SPAs are also often used to create progressive web apps, which offer users functions such as push notifications, offline access, and local caching.

Limitations of Single Page Applications

While both developers and users enjoy the numerous advantages of SPAs over traditional multi-page applications, SPAs are not without their drawbacks. Some of these disadvantages include:

Slower Initial Load Times: Since SPAs load the entire application at once, the initial load can often take much longer than a comparable site loaded one page at a time. This depends on how complex is the JavaScript code put in place to run the SPA. This setup can tax both server resources and user patience during the initial download.

SEO Difficulties: The structure of SPAs means that each “page” from the site comes from a single URL. This structure can limit the capabilities SPAs can use to take advantage of search engine optimization (SEO) techniques, such as landing pages, inbound links, and site authority. Although Google and other search engines have adjusted their indexing routines to take SPAs into account, developers can still encounter issues with achieving higher search engine results page (SERP) rankings.

Security Issues: The reliance on client-side JavaScript to run SPAs can also leave these applications vulnerable to security attacks, including cross-site scripting (XSS), in which hackers can inject malicious scripts into web-based applications. Without the proper precautions, SPAs can also expose a site owner’s sensitive data to users.

When to Use Single Page Applications (And When Not To)

For sites that aim to provide fast, seamless user experiences, SPAs can be a great fit. Social networks, as exhibited by sites such as Facebook and Twitter, are powerful examples of how SPAs can attract users. Developers can also use SPAs as the backbone for mobile apps, giving users a consistent experience across multiple devices. With cross-platform frameworks like React Native, SPAs can be ported to mobile quickly and easily.

If your application primarily displays static content such as blog or standard websites, then a single page application may not be the most cost effective solution. For highly dynamic experiences, however, SPAs can move a lot of the heavy lifting from your servers to client browsers.

Choose the Right CMS for Single Page Applications

If you’re convinced that a SPA is right for your organization, you need to make sure you choose a CMS that can get the job done. Ideally the CMS is API-first and can integrate smoothly with frontend frameworks without complex backend development. You may also want hybrid capabilities to ensure marketers can still use content authoring features.

Magnolia is a CMS that integrates seamlessly with AngularJS, a leading frontend framework used to develop SPAs, to help developers and content authors craft content rich websites. It’s API-first and has a rich set of personalization features that will fit well with a single page app to provide users with a dynamic digital experience.

What’s best, we’re working on bringing full-fledged visual editing and preview capabilities of single page apps, while also enabling devs to directly integrate their SPAs without the need to write Magnolia-specific templates at all. Stay tuned!

Jan Schulte

About the Author

Working at the intersection of business and technology, Jan helps Magnolia clients succeed with their content management and digital experience initiatives, framing solutions to their custom challenges and opportunities.