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- Herausgeber: Packt Publishing
- Kategorie: Fachliteratur
- Sprache: Englisch
Mongoid helps you to leverage the power of schema-less and efficient document-based design, dynamic queries, and atomic modifier operations. Mongoid eases the work of Ruby developers while they are working on complex frameworks.
Starting with why and how you should use Mongoid, this book covers the various components of Mongoid. It then delves deeper into the detail of queries and relations, and you will learn some tips and tricks on improving performance. With this book, you will be able to build robust and large-scale web applications with Mongoid and Rails.
Starting with the basics, this book introduces you to components such as moped and origin, and how information is managed, learn about the various datatypes, embedded documents, arrays, and hashes. You will learn how a document is stored and manipulated with callbacks, validations, and even atomic updates. This book will then show you the querying mechanism in detail, right from simple to complex queries, and even explains eager loading, lazy evaluation, and chaining of queries. Finally, this book will explain the importance of performance tuning and how to use the right indexes. It also explains MapReduce and the Aggregation Framework.
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Seitenzahl: 140
Veröffentlichungsjahr: 2013
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Table of Contents
Learning Mongoid
Learning Mongoid
Copyright © 2013 Packt Publishing
All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.
Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.
Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.
First published: December 2013
Production Reference: 1051213
Published by Packt Publishing Ltd.
Livery Place
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Birmingham B3 2PB, UK.
ISBN 978-1-78216-750-1
www.packtpub.com
Cover Image by Aniket Sawant (<[email protected]>)
Credits
Author
Gautam Rege
Reviewers
Ravil Bayramgalin
Simone Carletti
Sergio Tulentsev
Acquisition Editors
Pramila Balan
Subho Gupta
Commissioning Editor
Govindan K
Technical Editors
Dipika Gaonkar
Kapil Hemnani
Nikhil Potdukhe
Copy Editors
Roshni Banerjee
Mradula Hegde
Dipti Kapadia
Kirti Pai
Lavina Pereira
Laxmi Subramanian
Project Coordinator
Joel Goveya
Proofreader
Chris Smith
Indexer
Monica Ajmera Mehta
Production Coordinator
Arvindkumar Gupta
Cover Work
Arvindkumar Gupta
About the Author
Gautam Rege is driven by his passion for programming, he co-founded Josh Software with Sethupathi Asokan in 2007. He still codes religiously and leads the marketing of the India-based Josh Software brand across the world, apart from being involved in delivering web solutions for the client partners of the organization. With more than 13 years of experience in the industry, he has handled a wide array of profiles that have helped him to develop strong analysis and project management skills, and an understanding of client partner needs for sustainable and high-standard web solutions.
He is an ardent promoter of Ruby on Rails and leads many of the brand's initiatives to promote this framework in India. He helps organize the annual RubyConf India, talks at Ruby conferences across the world, and manages local Ruby meetings. When not discussing Ruby, he loves talking about entrepreneurship and the importance of starting up young! Apart from being an active voice through his popular blog, he has authored the book Ruby and MongoDB Web Development Beginner's Guide, Packt Publishing. He truly believes that Ruby is the language of the next generation of web application development.
Before beginning his professional career in 2000, he completed his B.E. from the Pune Institute of Computer Technology (PICT). In his spare time, apart from spending time with his family, he is an athlete and loves playing cricket, basketball, and soccer when he can. He is always on the lookout to feed his hunger for adventure by going for activities such as skydiving and bungee jumping.
Writing your second book is always easier than the first because one is already tuned to write late in the night and on weekends. This book has a lot of input from practical experiences I had while working at Josh. Without the support of Sethu to free up my work so that I could find time to write this book, it may never have been completed!
My wife Vaibhavi and daughter Swara provided a lot of moral support and both were very patient even when I missed out on family time and family occasions. Thank you very much! The book reviewers and technical editors provided excellent feedback and suggestions that have helped in my work.
About the Reviewers
Simone Carletti has been working professionally with Ruby since 2006. He's very passionate about code quality and best practices.
He has been involved with free and open source software (FOSS) for more than a decade, contributing code and creating libraries in several different programming languages. The most recent projects are available in his GitHub account (weppos).
Currently, he is working as a Software Developer at DNSimple—a company providing DNS hosting, domain registration, and SSL certificates. His personal website is http://www.simonecarletti.com/.
Sergio Tulentsev is an early MongoDB adopter and Mongoid fan. He has used them to build systems that handle substantial load (greater than 100 million hits per day). He often speaks about MongoDB at conferences and even patched it once or twice.
When not fending off bears in snowy Russia, he travels, tries new kinds of food, and learns new languages.
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Preface
Learning Mongoid gives beginners a good start to building a Rails application using MongoDB with Mongoid. For intermediate and expert Ruby developers, this book provides an excellent reference for using Mongoid. The book has plenty of examples with code samples and explanations that help in understanding the various features of Mongoid.
What this book covers
Chapter 1, What's so Awesome about Mongoid?, explains why Mongoid is one of the popular choices for Rails applications that use MongoDB. We are also introduced to Origin and Moped, which are integral parts of Mongoid.
Chapter 2, Mongoid Document Model, discusses the various data types that are supported by Mongoid and how they are stored. We learn about arrays, hashes, and embedded documents. We also briefly touch upon localized storage of string.
Chapter 3, Persisting Documents, discusses how documents are saved, format, optimization, and even managing custom data types and their serialization. We will also learn about atomic updates, callbacks, and validations.
Chapter 4, Mongoid Relations, explains the various relations that are supported by Mongoid, including One-to-One, One-to-Many, recursively embedded documents, and even polymorphic relations.
Chapter 5, Querying Attributes, explains everything about searching. We take a deep dive into how Origin works and how Mongoid criteria are managed. We learn about criteria chaining, lazy evaluation, and even eager loading of related documents.
Chapter 6, Performance Tuning, deals with how we can improve performance. We learn about the various indexes and when to use the right index. We see how the identity map can help in eager loading. Finally, we learn about MapReduce and the aggregation framework, which can drastically improve performance.
Chapter 7, Mongoid Modules, introduces various modules and gems available, which can help enhance the features with Mongoid. We learn about paranoid deletes, versioning, cloning, slugs, authentication, authorization using Devise, and even uploading documents using CarrierWave.
What you need for this book
This book assumes that you are using MacOS or Ubuntu Linux. It requires the latest MongoDB 2.4.x stable version, the latest Ruby 2.0 version, the latest Rails 4 version, and the latest Mongoid 4 version.
Who this book is for
This book is intended for beginners and experts alike. For a beginner, this book serves as an excellent guide for building Rails applications with Mongoid. For an intermediate or expert user, this book serves as an excellent reference for using the various features of Mongoid.
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Note
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Tip
Tips and tricks appear like this.
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Chapter 1. What's so Awesome about Mongoid?
The name MongoDB is derived from humongous. We use DataMappers to work with MongoDB. In Ruby, the most popular MongoDB mapper is Mongoid, pronounced mann-gyod. But is this the only mapper available? There also exists MongoMapper, MongoODM, and in the realm of open source there could well be many more!
So, what is so awesome about Mongoid? In a nutshell, its ability to gel with the Rails framework makes it very popular. For me, it is this adaptability to refactor and improve that makes Mongoid a very close ally of Rails.
In this chapter, we shall get a taste of the power of Mongoid. We shall see:
A practical approach using the Sodibee library system
Sodibee (pronounced saw-di-bee) is a library-management system that can manage books, reviews, authors, and bookings. Here are some of the functions that are supported in Sodibee:
Note
In the course of this book we will be working with the latest versions of Ruby 2.0, Mongoid 4, Rails 4, and MongoDB 2.4.
Checking prerequisites
First and foremost, we need to ensure that we have our development environment set up. It's common to use multiple versions of Ruby for development; I use RVM to manage these versions. As we can have multiple versions of the same gem installed on our machines, we use RVM gemsets to manage the gems we need for our work.
Ruby version
To check the Ruby version, check the version that is installed using the following command:
Note
Ruby 2.1 is due to be released in December, 2013. Everything in this book will be fully compatible with Ruby 2.1 too.
MongoDB version
We are currently using MongoDB v2.4.6—verify that, using the following command:
If you don't see this, it's quite likely that you have not installed MongoDB or it isn't running. Get going!
Setting up Sodibee
First and foremost, let's install the Rails gem.
This installs Rails 4.0.0.
Note
At the time of writing this book, the Rails version was 4.0.0. All commands would be fully compatible with the latest Rails version.
Now, let's create the Sodibee project.
