# Router

## Adding routes

Patchcore collects _routes_ from `router.sync.routes` as a reduce. It expects the final routes collection to be an array of arrays of the form:

```
  [ routeValidator, routeFunction ]
```

Where `routeValidator` is a function that returns true / false when given a `location` object.

Here's a simple example of extending the routes

```js
exports.create = (api) => {
  return { router: { sync: { routes } } }

  function routes (sofar = []) {
    const moreRoutes = [
      [ (location) => location.page === 'home',  api.app.page.home ],
      [ (location) => location.type === 'group', api.app.page.group ],
      [ ()         => true,                      api.app.page.notFound ]
    ]

    return [...moreRoutes, ...sofar]
    // Note order matters here
  }
}
```


## Using the router

The router is accessible at `app.sync.router`, and can be used like :

```js
const location = { page: 'inbox', theme: 'dark' }
const newView = api.app.sync.router(location)
```

The router finds the first route which matches the location it is passed, then automatically calls the associated `routeFunction` with the `location` object as an argument.

In our example the route is generating a view, which we might insert / append to the DOM, but this doesn't have to be the case.