Is there any need of learning views and template engines in express when we have already learn angular in the MEAN Stack

Question

I am learning MEAN Stack. I started from learning Angular(from angular.io) now I am learning node.js and express.js

My question is, if there is angular for front end in MEAN Stack then why there are views and template engines in express.js at back-end? Are they alternative for each other or complements each other? what is the boundary for the role and responsibility of these two?

I am looking forward for someone's help in clarifying of my concept for role these two technologies(express' views and angular) used in mean stack.

Answer 1

In order to answer your question, let me explain what is angular and what are template engines in express?

What is Angular?

Angular is a platform that makes it easy to build applications with the web. Angular combines declarative templates, dependency injection, end to end tooling, and integrated best practices to solve development challenges. Angular empowers developers to build applications that live on the web, mobile, or the desktop.

what is template engine?

A template engine enables you to use static template files in your application. At runtime, the template engine replaces variables in a template file with actual values and transforms the template into an HTML file sent to the client. This approach makes it easier to design an HTML page.

Some popular template engines that work with Express are Pug, Mustache, and EJS. The Express application generator uses Jade as its default, but it also supports several others.

So,

Angular is a framework with a templating component baked in. You use it to create Single page Web Applications which means that DOM modification is happening on the client side and the app exchange with server only data. If your concern is template it is plain HTML.

Whereas, template engines' rendered views are sent to client each time by server whenever request is made each time a new page is rendered on server and sent to the client which is Great for static sites but not for rich site interactions.

If there is angular for front-end in MEAN Stack then why there are views and template engines in express.js at back-end?

This is because not every time generating views from angular is recommended sometimes it is better to use Template Engines to generate views and send the rendered page to a client, generating views at client side has its own pros and cons and generating views at server side has its own.

Generating views using template engines (i.e. at server-side):

pros:

1. Search engines can crawl the site for better SEO.
2. The initial page load is faster.
3. Great for static sites.

cons:

1. Frequent server requests.
2. An overall slow page rendering.
3. Full page reloads.
4. Non-rich site interactions.

Generating views using angular engines (i.e. at client-side):

pros:

1. Rich site interactions
2. Fast website rendering after the initial load.
3. Great for web applications.
4. Robust selection of JavaScript libraries.

cons:

1. Low SEO if not implemented correctly.
2. The initial load might require more time.
3. In most cases, requires an external library.

So, after knowing the pros and cons, you yourself can better decide that in particular case which one is better for you. Mean Stack has provided options for developers.

As far as your question regarding the role of these two technologies is concerned, Angular is a lot more view generator only, It has features like routing, it as services two-way data binding etc while the template engines are meant to render HTML so that it can be sent to the client.

I hope you will find this answer useful.

References:

1. what is the template engine?
2. what is angular?
3. pros/cons

Answer 2

Angular is a full-fledged front-end framework that comes with its own way of doing templating, using angular-specific markup in your HTML. If you use Angular as your framework, you're more or less stuck with their way of templating within the Angular portion of your application.

Angular Features

• It is a framework written in Javascript language
• Manages state of models
• Integrates with other UI tools
• Manipulates DOM
• Allows writing custom HTML codes
• It is meant for javascript developers to create dynamic web pages in a quick time

NodeJS

• It serves the web
• It is runtime built on javascript engine in google chrome
• It can be considered as a lightweight server which can serve client requests in a more
• simpler way than java does
• It performs communication operation with databases, web-sockets, middleware etc.

Why we use angular for Tempting not Express/Node tempting Engine

Server-side rendering is the most common method for displaying information onto the screen. It works by converting HTML files in the server into usable information for the browser.

Whenever you visit a website, your browser makes a request to the server that contains the contents of the website. The request usually only takes a few milliseconds, but that ultimately depends on a multitude of factors:

• Your internet speed
• how many users are trying to access the site and
• how optimized the website is, to name a few

Once the request is done processing, your browser gets back the fully rendered HTML and displays it on the screen. If you then decide to visit a different page on the website, your browser will once again make another request for the new information. This will occur each and every time you visit a page that your browser does not have a cached version of.

It doesn’t matter if the new page only has a few items that are different than the current page, the browser will ask for the entire new page and will re-render everything from the ground up.

How client-side rendering works

When developers talk about client-side rendering, they’re talking about rendering content in the browser using JavaScript. So instead of getting all of the content from the HTML document itself, you are getting a bare-bones HTML document with a JavaScript file that will render the rest of the site using the browser.

This is a relatively new approach to rendering websites, and it didn't really become popular until JavaScript libraries started incorporating it into their style of development.

See Examples HerePratical Example