/actionhero-tutorial

An example actionhero project demonstrating many common features

Primary LanguageJavaScript

actionhero Tutorial

  • created: June 22, 2013
  • updated: April 25, 2018

Build Status

This guide will walk you through the creation of the application in this repository, and in the process you will learn some of the basics of ActionHero.

You will become comfortable with the following topics:

A simple Blogging API & site:

Adding a chat room

Next Steps

ActionHero Resources

Notes

  • You are expected to have a basic familiarity with node.js and the command line
  • You do not need to clone this repository to follow this guide. The code in this repository represents the final state of a project created with these instructions. The code in this project should serve as a reference.
  • You should also be able to run this project by:
    • git clone https://github.com/actionhero/actionhero-tutorial.git
    • cd actionhero-tutorial
    • npm install
    • npm start
    • There are a few extra steps needed to persists data to redis.
  • This project uses redis as a database. You will need to have it installed on your computer.
  • Remember that ActionHero is an API server, so we will be focusing on creating an API for blogging and chatting, and applying that to a website rather than creating a beautiful website itself.

Getting Started with a new actionhero Project

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ActionHero is a node.js package. Be sure you have node.js (version >= 8.0.0) installed. Node comes with npm, the node package manager. npm includes a command npx we can use to run actionhero simply.

This guide was written on OSX It should be appropriate for any version of OSX > 10.6. It should also work on most Linux distributions (Ubuntu, CentOs, Fedora, etc). The concepts presented here should also be appropriate for windows users, but many of the "Getting Started" commands will not work as described here. If you are looking for help on getting started on Windows, Mark Tucker has a video tutorial for windows users

Create a new directory for this project and enter it (in the terminal):

  • mkdir ~/actionhero-tutorial
  • cd ~/actionhero-tutorial

note: From this point forward, it is assumed that all commands listed are run from within the ~/actionhero-tutorial directory.

Install the actionhero package locally from NPM:

  • npm install actionhero

Use the ActionHero generator to build your project

  • npx actionhero generate

Install any project dependancies

  • npm install

Try to boot the ActionHero server

  • npm start

You should see the default ActionHero welcome page at http://localhost:8080/public (visit in your browser)

The port 8080 is defined in /config/servers/web.js, along with all other settings for ActionHero. ActionHero has two types of http routes: static files and api routes. static files are served from /public and the api is served from /api. These routes are configurable. ActionHero also picks one of these to be the default root route. This is defined by api.config.servers.web.rootEndpointType. As we want to make a website, lets change that from api to file.

Restart your server by pressing ctrl+c in the terminal window running ActionHero. Start up the server again (npm start) and visit http://localhost:8080/ and you should see the welcome page. You will note that the setting we just changed was under the servers.web section. This is because this setting is only relevant to HTTP clients, and not the others (socket, websocket, etc). We will talk about these more later.

We should also enable all the servers which ship with ActionHero (web, websocket, and socket). Enable their sections in their config files

Lets change one more thing in config/api.js: development mode. Change api.config.general.developmentMode = true Development mode is helpful while creating a new application as it will automatically restart your server on configuration changes, and watch and reload your actions and tasks as you change them.

ActionHero uses the variable NODE_ENV to determine which modification file to load from /config/* to load to modify the default values in api.config. This is how you can set different variables per environment. We will use this for testing later.

Creating Initializers

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Initializers in ActionHero are places to save common code which other parts of your application will use. Here is where you might connect to your database or define middlewares. Normally, you append your new classes to the api object so it becomes available in scope for your actions and tasks (like api.mysql or api.game). When your server boots, you can optionally execute code within a start method.

Because we are building a blog, first we will need a place to store our entries and comments. As ActionHero already has redis available under api.redis.client, lets use that for our data store.

Create a new initializer for the blog's common functions:

  • npx actionhero generate initializer --name=blog

I'll define some common blog functions we'll use later in actions in initializers/blog.js

Our blogging methods are:

api.blog = {
  // constants
  separator: ";",
  postPrefix: "posts",
  commentPrefix: "comments:",
  // posts
  postAdd: function(userName, title, content){},
  postView: function(userName, title){},
  postsList: function(userName){},
  postEdit: function(userName, title, content){},
  postDelete: function(userName, title){},
  // comments
  commentAdd: function(userName, title, commenterName, comment){},
  commentsView: function(userName, title){},
  commentDelete: function(userName, title, commentId){},
}

A few things to note:

  • posts are hashes with the content and some additional meta data
  • comments are also hashes, a key for each comment
  • we always make asynchronous functions, using async/await. ActionHero does not use the callback pattern.
  • at this layer, we don't worry about authentication or validations

Users & Authentication

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We know we will need to authenticate users to our blog, so lets make another initializer to handle this as well.

  • npx actionhero generate initializer --name=users

Our user methods are:

api.users = {
  // constants
  usersHash: "users",
  // methods
  add: function(userName, password){},
  list: function(){},
  authenticate: function(userName, password){},
  delete: function(userName, password){},
}

Notes:

  • We are again storing all data in a redis hash
  • If we delete a user, we should delete all the posts and comments from them

Public and Private actions with Middleware

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In the steps above, we created a api.users.authenticate method, but didn't use it anywhere. There are clearly methods which should be protected (like adding a post, or deleting a user), but we need to safeguard them somehow.

In ActionHero, we know that we will wrap any use of our initializer's methods by users in actions, so we can create a middleware which we can apply to these actions.

Let's create a new initializer for this:

  • npx actionhero generate initializer --name=middleware

There are arrays of functions in ActionHero which will be run before an after every action. Here, we only need a check before to see if an action should be run. You have access to the action itself, along with the connection.

The middleware we created allows us to simply append action.authenticated = true to the action definition, and the middleware will be invoked.

Middlewares are stored to the api by adding them via api.actions.addMiddleware(authenticationMiddleware).

Creating Actions

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Now that we have our helpers for getting and setting blog posts, how can we allow users to use them? Actions!

Action files can define a few actions each, so lets create one for comments and one for posts.

  • npx actionhero generate action --name=users
  • npx actionhero generate action --name=blog

Note how we added action.authenticated = true on the actions which required security.

Now we can use CURL to test out our API! Note that right now, all HTTP methods will work (get, post, etc). We'll be setting up routing next. Be sure to URL-encode all your input.

  • Add a user:
    • curl -X POST -d "userName=evan" -d "password=password" "http://localhost:8080/api/userAdd"
  • Check that you can log in:
    • curl -X POST -d "userName=evan" -d "password=password" "http://localhost:8080/api/authenticate"
  • Add a post:
    • curl -X POST -d "userName=evan" -d "password=password" -d "title=first-post" -d "content=My%20first%20post.%20%20Yay." "http://localhost:8080/api/postAdd"
  • View the post
    • curl -X POST -d "userName=evan" -d "title=first-post" "http://localhost:8080/api/postView"
  • Add a comment
    • curl -X POST -d "userName=evan" -d "title=first-post" -d "comment=cool%20post" -d "commenterName=someoneElse" "http://localhost:8080/api/commentAdd"
  • View the comments
    • curl -X POST -d "userName=evan" -d "title=first-post" "http://localhost:8080/api/commentsView"

Routes

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We have the basics of our API working, but it might be tedious to keep using GET and POST params. It's time to set up routes. Routes allow different HTTP verbs to preform a different action on the same URL. We'll use a config/routes.js file to transform our API into restful resources for users, comments, and posts. You can derive input variables from the structure of URLs with routing as well.

Now we can get the list of posts for user evan with curl -X GET "http://localhost:8080/api/posts/evan" and we don't need to pass any parameters.

  • I can get a list of my posts with http://localhost:8080/api/posts/evan
  • I can view a post with http://localhost:8080/api/post/evan/first-post
  • etc

Testing

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There are many testing tools and packages which exist for nodejs. ActionHero is not opinionated about which testing framework you should use, but nonetheless, testing is important! ActionHero exposes a number of utilities to make it easy to boot up a server with configuration overrides to make testing easier.

Lets setup a test with the jest package. We'll use the request package to make HTTP requests simpler in our tests.

npm install --save-dev jest request (and add them to your package.json in the devDependencies section).

We can now run the test with the jest command. In our package.json we can also setup npm test to run the test suite how we would like it: "test": "jest". Jest will automatically set NODE_ENV=test for us, to tell ActionHero we are running this command in the 'test' environment this will signal ActionHero load any configChanges from the /config/environments/test.js file. Here we setup redis and the servers how we want for testing.

A successful test run looks like this:

We also use the npm lifecycle command pretest to run a linter, standard. This helps our code to conform to a consistent style and will check for errors like variable scope.

Consuming the API via the Web

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ActionHero is primarily an API server, but it can still serve static files for you. In config/api.js, the api.config.general.paths.public directive is where your web site's "root" is. You can also use actions to manipulate file content with the api.staticFile.get method. ActionHero is also a great choice to power your front-end applications (angular.js, ember, etc).

Provided in index.html is a simple page which demonstrates how simple it is to call an action from the web to document the API we have created. If you visit the the showDocumentation action (generated with a new project), ActionHero will describe it's capabilities, and we can then render them on our web page.

Sockets

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While this application probably makes the most sense being used in a web browser, ActionHero can still provide a TCP/Socket API for clients who wish to use it. There is nothing new you need to do to enable it other than set enabled in ./config/servers/socket.js.

Let's add a comment with the socket API and Telnet. We'll make some mistakes so you can see how error responses are handled. You will also notice how with TCP clients, params are 'sticky' by default, and you only need to set them once per session.

> telnet localhost 5000

Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.

{"welcome":"Hello! Welcome to the actionhero api","room":"defaultRoom","context":"api"}
paramAdd userName=evan
{"status":"OK","context":"response","data":null,"messageCount":1}
paramAdd title=first-post
{"status":"OK","context":"response","data":null,"messageCount":2}
paramsView
{"status":"OK","context":"response","data":{"limit":100,"offset":0,"userName":"evan","title":"first-post"},"messageCount":3}
postsList
{"posts":["first-post"],"context":"response","messageCount":4}
paramAdd comment=a-comment-from-tcp
{"status":"OK","context":"response","data":null,"messageCount":5}
commentAdd
{"error":"Error: commenterName is a required parameter for this action","context":"response","messageCount":6}
paramAdd commenterName=tcp-client
{"status":"OK","context":"response","data":null,"messageCount":7}
commentAdd
{"context":"response","messageCount":8}
commentsView
{"comments":[{"comment":"a-comment-from-tcp","createdAt":1372223802362,"commentId":"tcp-client1372223802362"}],"context":"response","messageCount":9}
exit

Websockets

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/public/chat.js demonstrates how to use ActionHero's websockets. The websocket is a first-class protocol in ActionHero and has all the capabilities of web and socket. Like socket, it is a persistent connection which also enables ActionHero's chat room features. We will make use of them here.

Note that we include both the javascript actionheroWebSocket.js

Note how we make use of the event libraries of actionheroWebsocket and build our events around it. This librars is accessed by including /public/javascript/actionHeroClient.min.js in your html page.:

A = new actionheroWebSocket;

A.events = {
  say: function(message){
    A.log(message);
    appendMessage(message);
  },
  alert: function(message){
    alert(message.message);
  },
  welcome: function(message){
    A.log(message);
    appendMessage(message);
  }
}

A.connect(function(err, details){
  if(err != null){
    A.log(err);
  }else{
    A.log("CONNECTED");
  }
});

Tasks

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ActionHero comes with a robust task system for delayed / recurring tasks. For our example, we are going to create a task which will log some stats to the command line every 30 seconds. You can do much more with ActionHero's task system, including distributed tasks, recurring tasks, and more.

npx actionhero generate task --name=stats --queue=default --frequency=30000

  • note how we set the task.frequency to run every 30 seconds
  • to enable our server to run tasks, we need to configure 'workers' to run. You can enable minTaskProcessors and maxTaskProcesssors in /config/tasks.js (set them both to 1).
  • to re-scheudle a job like ours, you will also need to enable the scheduler process in /config/tasks.js.

Next Steps / TODO

  • Use cookie-based authentication rather than requiring the password and userName to be sent with each request
  • Migrate to another database
  • Implement a UI for the API
  • Tests should be more inclusive, and test failure cases
  • Pagination for all the *view actions