Express in Action

258 Pages·2016·4.759 MB·English

by  Evan Hahn

M A N N I N G
IN ACTION
Writing, building, and testing
Node.js applications
Evan M. Hahn
Express in Action

Express in Action
Writing, building,
and testing Node.js
applications
EVAN M. HAHN
MANNING
SHELTER ISLAND
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brief contents
PART 1 INTRO ..........................................................................1
1 ■ What is Express? 3
2 ■ The basics of Node.js 18
3 ■ Foundations of Express 31
PART 2 CORE..........................................................................51
4 ■ Middleware 53
5 ■ Routing 70
6 ■ Building APIs 87
7 ■ Views and templates: Pug and EJS 104
PART 3 EXPRESS IN CONTEXT................................................117
8 ■ Persisting your data with MongoDB 119
9 ■ Testing Express applications 146
10 ■ Security 172
11 ■ Deployment: assets and Heroku 193
12 ■ Best practices 218
v

contents
preface xiii
acknowledgments xiv
about this book xvi
about the cover illustration xix
PART 1 INTRO...............................................................1
1 What is Express? 3
1.1 What is this Node.js business? 4
1.2 What is Express? 6
The functionality in Node.js 6 ■ What Express adds to Node.js 8
1.3 Express’s minimal philosophy 9
1.4 The core parts of Express 9
Middleware 10 ■ Routing 11 ■ Subapplications 11
Conveniences 12
1.5 The ecosystem surrounding Express 12
Express vs. other web application frameworks 12 ■ What Express is
used for 14 ■ Third-party modules for Node.js and Express 14
1.6 The obligatory Hello World 16
1.7 Summary 16
vii
viii CONTENTS
2 The basics of Node.js 18
2.1 Installing Node 19
Running your first Node script 19
2.2 Using modules 20
Requiring built-in modules 20 ■ Requiring third-party modules
with package.json and npm 21 ■ Defining your own modules 24
2.3 Node: an asynchronous world 25
2.4 Building a web server with Node: the http module 28
2.5 Summary 30
3 Foundations of Express 31
3.1 Middleware 32
Hello World with Express 33 ■ How middleware works at
a high level 34 ■ Middleware code that’s passive 36
Middleware code that changes the request and response 37
Third-party middleware libraries 38
3.2 Routing 40
3.3 Extending request and response 41
3.4 Views 43
3.5 Example: putting it all together in a guestbook 44
Getting set up 45 ■ The main app code 45
Creating the views 46 ■ Start it up 48
3.6 Summary 49
PART 2 CORE..............................................................51
4 Middleware 53
4.1 Middleware and the middleware stack 54
4.2 Example app: a static file server 55
Getting set up 56 ■ Writing your first middleware function:
the logger 58 ■ The static file server middleware 60
404 handler middleware 61 ■ Switching your logger to an
open source one: Morgan 63 ■ Switching to Express’s built-in
static file middleware 64
4.3 Error-handling middleware 65
4.4 Other useful middleware 68
4.5 Summary 69
CONTENTS ix
5 Routing 70
5.1 What is routing? 70
A simple routing example 71
5.2 The features of routing 71
Grabbing parameters to routes 72 ■ Using regular expressions to
match routes 72 ■ Grabbing query arguments 74
5.3 Using routers to split up your app 74
5.4 Serving static files 76
Static files with middleware 76 ■ Routing to static files 78
5.5 Using Express with HTTPS 78
5.6 Putting it all together: a simple routing demo 80
Setting up 81 ■ The main app code 81 ■ The two views 83
The application in action 85
5.7 Summary 85
6 Building APIs 87
6.1 A basic JSON API example 88
6.2 A simple Express-powered JSON API 90
6.3 Create, read, update, delete APIs 92
HTTP verbs (also known as HTTP methods) 93
CRUD applications with HTTP methods 95
6.4 API versioning 96
6.5 Setting HTTP status codes 99
Setting HTTP status codes 100 ■ The 100 range 101
The 200 range 101 ■ The 300 range 102 ■ The 400
range 102 ■ The 500 range 103
6.6 Summary 103
7 Views and templates: Pug and EJS 104
7.1 Express’s view features 105
A simple view rendering 105 ■ A complicated view
rendering 105 ■ Making all view engines compatible
with Express: Consolidate.js 108
7.2 Everything you need to know about EJS 109
The syntax of EJS 109