Book Image

MEAN Web Development

By : Amos Q. Haviv
Book Image

MEAN Web Development

By: Amos Q. Haviv

Overview of this book

The MEAN stack is a collection of the most popular modern tools for web development; it comprises MongoDB, Express, AngularJS, and Node.js. Starting with MEAN core frameworks, this project-based guide will explain the key concepts of each framework, how to set them up properly, and how to use popular modules to connect it all together. By following the real-world examples shown in this tutorial, you will scaffold your MEAN application architecture, add an authentication layer, and develop an MVC structure to support your project development. Finally, you will walk through the different tools and frameworks that will help expedite your daily development cycles. Watch how your application development grows by learning from the only guide that is solely orientated towards building a full, end-to-end, real-time application using the MEAN stack!
Table of Contents (18 chapters)
MEAN Web Development
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Using Mongoose middleware


Mongoose middleware are functions that can intercept the process of the init, validate, save, and remove instance methods. Middleware are executed at the instance level and have two types: pre middleware and post middleware.

Using pre middleware

Pre middleware gets executed before the operation happens. For instance, a pre-save middleware will get executed before the saving of the document. This functionality makes pre middleware perfect for more complex validations and default values assignment.

A pre middleware is defined using the pre() method of the schema object, so validating your model using a pre middleware will look like the following code snippet:

UserSchema.pre('save', function(next) {
  if (...) {
    next()
  } else {
    next(new Error('An Error Occured'));
  }
});

Using post middleware

A post middleware gets executed after the operation happens. For instance, a post-save middleware will get executed after saving the document. This functionality makes post...