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Mongoose for Application Development

You're reading from   Mongoose for Application Development Mongoose streamlines application development on the Node.js stack and this book is the ideal guide to both the concepts and practical application. From connecting to a database to re-usable plugins, it's all here.

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Product type Paperback
Published in Aug 2013
Publisher Packt
ISBN-13 9781782168195
Length 142 pages
Edition 1st Edition
Languages
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Author (1):
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Simon Holmes Simon Holmes
Author Profile Icon Simon Holmes
Simon Holmes
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Table of Contents (18) Chapters Close

Mongoose for Application Development
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
1. Introducing Mongoose to the Technology Stack 2. Establishing a Database Connection FREE CHAPTER 3. Schemas and Models 4. Interacting with Data – an Introduction 5. Interacting with Data – Creation 6. Interacting with Data – Reading, Querying, and Finding 7. Interacting with Data – Updating 8. Interacting with Data – Deleting 9. Validating Data 10. Complex Schemas 11. Plugins – Re-using Code Index

Doing it your way – create custom validation


Mongoose offers a number of different ways to create custom validators.

Single function – no custom error message

If you only need one piece of validation for a given data item, you can simply specify a function and return true if the validation is passed, and false if it fails.

For example, if we want our usernames to be at least five characters long, we can create a function like the following:

var lengthValidator = function(val) {
  if (val && val.length >= 5){
    return true;
  }
  return false;
};

The function is then referenced in our schema using the validate key:

name: {type: String, required: true, validate: lengthValidator }

This is a very quick and easy way of adding custom validation. It is fine if you just want to check if its okay or not okay as it is reported as an error, but in the error collection the error type comes through as undefined.

Returning a custom error message

If you want a bit more feedback and granularity to your...

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