Building web applications with Clojure - code

This repository contains source codes for the Building web applications with Clojure screencast, published by PacktPub.

Please note, that this code is provided for demonstrational purposes only and was written live during short videos. Therefore, it is kind of pointless to use it without commentary provided in the video course itself.

Each video has a separate git tag for version of code available at the end of it, so you can walk through the progress of the tutorials or jump to the one you're currently browsing.

For example, video 2 of section 3, is tagged as SECTION3_VIDEO2, which video 1 of section 5 is tagged as SECTION5_VIDEO1.

Each section and video is described below, so you can easily browse the code and access external links to tools and libraries mentioned in each video.

Feel free to fork and play around with this repo!

Section 1: Getting Started

In this section, the reader will learn how to create a Leiningen project, configure Ring dependencies and plugins and start the web server from a command line.

Reference links:

• Leiningen build tool, https://github.com/technomancy/leiningen
• Ring
• Leiningen Ring plugin

Videos:

• Video 1: project setup
• Video 2: lein-ring plugin
• Video 3: simple Ring handler
• Video 4: running Ring server
• Video 5: building web application packages

Section 2: Ring Handlers

This section will explain how handlers in Ring work, what do they do and how we can access HTTP request manipulate an HTTP response. We will also see how to dispatch calls to different functions and introduce general mechanisms.

Reference links:

• Leiningen Ring plugin configuration
• Ring handlers
• Ring response and request map attributes

Videos:

• Video 1: Ring handler anatomy
• Video 2: request map
• Video 3: response map
• Video 4: routing
• Video 5: not found and error handling

Section 3: Middleware

In this section, I will explain how Ring middleware works. Then, I will implement an example middleware. Finally, use of existing middleware will be shown.

Reference links:

• Ring middleware concept
• Ring file middleware

Videos:

• Video 1: introduction
• Video 2: example
• Video 3: altering request and response
• Video 4: using existing middleware

Section 4: Forms & sessions handling

In this section, I will show to handle POST/GET parameters from Clojure web application, generate HTML content from Clojure level, manipulate cookies and manage Ring sessions.

Reference links:

• Ring parameter support
• Ring file upload
• Ring cookies
• Ring sessions

Videos:

• Video 1: Form handling
• Video 2: Generating HTML content
• Video 3: Manipulating cookies
• Video 4: Ring sessions

Section 5: Building RESTful API

This section will show how we can easily build a RESTful, JSON-based API with Clojure/Ring.

Reference links:

• REST page on Wikipedia

Videos:

• Video 1: API introduction and routing
• Video 2: Example RESTful API
• Video 3: Handling errors in REST API

Section 6: Database connectivity

In this section, I will showcase how can we integrate a popular databases - PostgreSQL and MongoDB with Clojure web app. For PostgreSQL, popular Clojure ORM framework - Korma, will be introduced.

Reference links:

• PostgreSQL home page
• clojure.java.jdbc
• Korma
• MongoDB
• Monger
• Congomongo

Videos:

• Video 1: Connecting to PostgreSQL
• Video 2: Using Korma
• Video 3: Connecting to MongoDB

Section 7: ClojureScript

This section will cover how to build basic ClojureScript logic, access JavaScript functions and how to integrate it with Clojure RESTful interface server-side.

Reference links:

• ClojureScript
• lein-cljsbuild plugin

Videos:

• Video 1: ClojureScript
• Video 2: Manipulating DOM tree with ClojureScript
• Video 3: Accessing REST API from ClojureScript

Section 8: Useful web libraries in Clojure

In this section, I will show most popular and useful web libraries available for Clojure - Compojure for routing, Hiccup and Enlive for HTML templating and Liberator for building RESTful APIs.

Reference links:

• Compojure
• Hiccup
• enlive
• Liberator

Videos:

• Video 1: Routing with Compojure
• Video 2: HTML generation with Hiccup
• Video 3: HTML templating with enlive
• Video 4: REST API with Liberator