How to include Ember into an existing Node/Express.js App

Question

I'm working on including Ember into an already deployed Node/Express/EJS application. I don't want to disrupt any of the existing application behavior, but instead, want build out any additional feature to the app using Ember. The server side code for these new features has already been built, and each endpoint returns the JSON format that Ember Data expects. I've been looking into Ember App Kit and Ember-cli, but I'm not sure how to include these tools into my existing directory structure, and I'm not certain if these are in face the right tools for my use case. Does anyone have any experience with this particular use case?

For example, navigating to /foo returns the existing express route that renders an ejs template, but /bar would be an Ember route that hits the api endpoint of the same name.

Answer 1

Use ember-cli (ember-cli.org). It's perfect for this situation as it allows you to rapidly prototype out your ember app. It even comes with an expressJS based testing suite and mocks server.

Once you are ready to incorporate it to your NodeJS, Flask, or whatever other application all static files should be available in the ember-cli dist directory.

Just don't forget to build the ember-cli project before porting via the means of ember build. After that it's just a simple matter of moving the files in the ember projects dist folder into wherever you need in your environment.

Just to embellish a bit: Ember-cli has a great work-flow for use while building your ember app. Try ember serve for a quick example. I mention this because it speaks to your question of how to incorporate this into your existing project (by project, I assume you may mean workflow). I typically will build ember projects purely using ember-cli and consider the back-end (usually a REST-API exposed via either Flask or NodeJS) a separate concern. When importing the app all I have to concern myself with is making sure my server serves the correct static dist files.

I would not recommend using the Ember App Kit (EAK) as it has been deprecated in favor of ember-cli. It really is.. much, much better.

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Ok so I'm going to try to be more complete in this answer. Let's start with the isolated question - ember-cli or eak? Definitely Ember-Cli, but why?

1. EAK is officially heading for deprecation in favor of ember-cli.
2. Ember-cli produces more structured, cleaner, maintainable ember code.
3. Ember-cli integrates your entire ember-app workflow.
4. Managing all types of dependencies and assets is made simple via bower install --save and Brocfile.js edits. (See the ember-cli docus for explanation)

Now the more complicated part of the question. How do I integrate this with an existing workflow? I recently ran into this when building a webrtc-included ember app. It just so happened that this was my first real use of ember as well. So, not yet realizing the full potential of my new hammer I wrote the REST API, Backend ORM layer, the signalling service, the session cache, and built a complete CI workflow first. Then I was ready to build my ember app and ended up in your exact position.

To short circuit a long story - the lesson I learned was that I should treat my ember-cli app like a completely separate concern. What I mean here is - there's my backend (NodeJS, Apache, Nginx... whatever) and what I code here is built, tested and integrated separately. It normally even lives in its own git repository. It's a separate concern to my front end equation which typically would consist of several components itself. My I-Phone Native app would have its own workflow from build-to-test and integrate to my backend via a REST API. My Android native app another. My web app another. For all intents and purposes, in my workflow these are entirely separate workflows that only tie together when we start talking Continuous Integration.

There's a lot of arguments for why you'd want to do this. Most importantly - it scales.

The beauty of ember-cli is that it makes it fairly trivial to get a workflow for your ember app going and trivial to redeploy your app + workflow on a new box/instance. I would certainly recommend referring to the official ember-cli setup instructions but I'm going to include them here in case the URL goes bad one day:

No really, refer to the link my instructions will suck in comparison...

Deploying a new Ember App

1. Install NodeJS, NPM and Git (ember-cli will as a default load git going for you on new apps) on your system via sudo apt-get install nodejs and sudo apt-get install npm, sudo apt-get install git.

Note: On Ubuntu 14.04 and some other Debian systems use sudo apt-get install nodejs-legacy instead. If in doubt, use legacy. If you experience problems using the node command after install, it's definitely that you need to use nodejs-legacy. Don't bother trying to do the linking manually.

2. Install required node modules globally: sudo npm install -g ember-cli, sudo npm install -g bower, sudo npm install -g phantomjs

3. Create new ember-cli app: cd <Desired Directory>, ember new my-app-name

Now you can look at ember help to begin learning how to use ember-cli. Hint: The --dry-run flag is your friend. You'll notice that when you installed ember-cli all the scaffolding was taken care of for you. You'll see that you can add things with simple ember generate commands and they will not only create the required objects, but the test files as well. Best of all, using ember serve you can start scaffolding your app and via simple flags you can configure the test server to actually proxy and use your already-existing REST API (if you have one) or the expressJS mocks server to build a psuedo-API.

Integrating it with your larger workflow from here is a simple matter of configuring whatever tools you use (I use Jenkins and Ansible for this kind of stuff) to distribute the dist folder of ember-cli to where it should go to be served as static content (it is just a single page webapp in the end).

If you want to instead play with an existing ember-cli app that operates in an isolated workflow and already makes use of most of the goodies in order to get some familiarity - as I suspect you'll quickly realize how to fit this into whatever your current structure is - feel free to clone and play with this one here.

And so finally - to answer the more specific question of how this might fit into an existing directory structure, I would break this down into two categories. When we're talking src - I would have it in it's own "structure", separated at least by being in a separate sub-directory of its own. When we're talking built and deliverable I would include the contents of the /dist folder in whatever static web server directory you want to serve your ember app from.

EDIT: I Added some more detail - hopefully useful details below the line break. Let me know if you have more questions or if I can explain anything better.