<h3class="second padded"><divclass="number">2</div> Start a Plugin</h3>
<p>Plugins lie at the heart of N1. The thread list, composer and other core parts of the app are plugins bundled with the app, and you have access to the same set of APIs. From the Developer Menu, choose <spanclass="instruction-literal">Create a Plugin...</span> and name your new plugin.</p>
<p>Your new plugin comes with some basic code that adds a section to the message sidebar, and it's already enabled! View a message to see it in action. If you make changes to the source, choose <spanclass="instruction-literal">View > Refresh</span> to see your changes in N1.</p>
<p>Nylas is built on the modern web - plugins are written in CoffeeScript or JavaScript. Plugins are a lot like node modules, with their own source, assets, and tests. Check out yours in <spanclass="instruction-literal">~/.nylas/dev/packages</span>.</p>
<p>In N1, select <spanclass="instruction-literal">Developer > Run Plugin Specs...</span> from the menu to run your plugin's new specs. Nylas and its plugins use the Jasmine testing framework.</p>
We're going to build on this to show the sender's [Gravatar](http://gravatar.com) image in the sidebar, instead of just their name. You can check out the full code for the plugin [in the sample plugins repository](https://github.com/nylas/edgehill-plugins/tree/master/sidebar-gravatar).
> We use [CJSX](https://github.com/jsdf/coffee-react), a [CoffeeScript](http://coffeescript.org/) syntax for [JSX](https://facebook.github.io/react/docs/jsx-in-depth.html), to streamline our plugin code.
For syntax highlighting, we recommend [Babel](https://github.com/babel/babel-sublime) for Sublime, or the [CJSX Language](https://atom.io/packages/language-cjsx) Atom package.
### Changing the data
Let's poke around and change what the sidebar displays.
You'll find the code responsible for the sidebar in `lib/my-message-sidebar.cjsx`. Take a look at the `render` method -- this generates the content which appears in the sidebar.
(How does it get in the sidebar? See [Interface Concepts](interfaceconcepts) and look at `main.cjsx` for clues. We'll dive into this more later in the guide.)
We can change the sidebar to display the contact's email address as well. Check out the [Contact attributes](reference/contact) and change the `_renderContent` method to display more information:
Now we've figured out how to show the contact's email address, we can use that to generate the [Gravatar](http://gravatar.com) for the contact. However, as per the [Gravatar documentation](https://en.gravatar.com/site/implement/images/), we need to be able to calculate the MD5 hash for an email address first.
> JSX Tip: The `{..}` syntax is used for JavaScript expressions inside HTML elements. [Learn more](https://facebook.github.io/react/docs/jsx-in-depth.html).
Now the Gravatar image associated with the currently focused contact appears in the sidebar. If there's no image available, the Gravatar default will show; you can [add parameters to your image tag](https://en.gravatar.com/site/implement/images/) to change the default behavior.
If you're a fan of using the Chrome Developer Tools to tinker with styles, no fear; they work in N1, too. Open them by going to `Developer > Toggle Developer Tools`. You'll also find them helpful for debugging in the event that your plugin isn't behaving as expected.
Building on the [previous part](getting-started-2) of our Getting Started guide, we're going to introduce a data store to give our sidebar superpowers.
## Stores and Data Flow
The Nylas data model revolves around a central `DatabaseStore` and lightweight `Models` that represent data with a particular schema. This works a lot like ActiveRecord, SQLAlchemy and other "smart model" ORMs. See the [Database](database) explanation for more details.
Using the [Flux pattern](https://facebook.github.io/flux/docs/overview.html#structure-and-data-flow) for data flow means that we set up our UI components to 'listen' to specific data stores. When those stores change, we update the state inside our component, and re-render the view.
We've already used this (without realizing) in the [Gravatar sidebar example](getting-started-2):
In this case, the sidebar listens to the `FocusedContactsStore`, which updates when the person selected in the conversation changes. This triggers the `_onChange` method which updates the component state; this causes React to render the view with the new state.
* Create our own data store which will listen to `FocusedContactsStore`
* Extend our data store to do additional things with the contact data
* Update our sidebar to listen to, and display data from, the new store.
In this guide, we'll fetch the GitHub profile for the currently focused contact and display a link to it, using the [GitHub API](https://developer.github.com/v3/search/).
## Creating the Store
The boilerplate to create a new store which listens to `FocusedContactsStore` looks like this:
# TBD - This is fired when the focused contact changes
@trigger(@)
```
(Note: You'll need to set up the `reflux` dependency.)
You should be able to drop this store into the sidebar example's `componentDidMount` method -- all it does is listen for the `FocusedContactsStore` to change, and then `trigger` its own event.
Let's build this out to retrieve some new data based on the focused contact, and expose it via a UI component.
## Getting Data In
We'll expand the `_onFocusedContactChanged` method to do something when the focused contact changes. In this case, we'll see if there's a GitHub profile for that user, and display some information if there is.
The `console.log` line should show the GitHub profile for a contact (if they have one!) inside the Developer Tools Console, which you can enable at `Developer > Toggle Developer Tools`.
You may run into rate-limiting issues with the GitHub API; to avoid these, you can add [authentication](https://developer.github.com/v3/#authentication) with a [pre-baked token](https://github.com/settings/tokens) by modifying the HTTP request your store makes. **Caution! Use this for local development only.** You could also try implementing a simple cache to avoid making the same request multiple times.
## Display Time
To display this new data in the sidebar, we need to make sure our component is listening to the store, and load the appropriate state when it changes.
```coffee
class GithubSidebar extends React.Component
...
componentDidMount: =>
@unsubscribe = GithubUserStore.listen(@_onChange)
_onChange: =>
@setState(@_getStateFromStores())
_getStateFromStores: =>
github: GithubUserStore.getProfile()
```
Now we can access `@state.github` (which is the GitHub user profile object), and display the information it contains by updating the `render` and `renderContent` methods.
To make this plugin more compelling, we can extend the store to make further API requests and fetch more data about the user. Passing this data back to the UI component follows exactly the same pattern as the barebones data shown above, so we'll leave it as an exercise for the reader. :)
> You can find a more extensive version of this example in our [sample plugins repository](https://github.com/nylas/edgehill-plugins/tree/master/sidebar-github-profile).
