# Routing

## Routing

| callbag                                                                                                                           | most                                                                                                                           | RxJS                                                                                                                           | xstream                                                                                                                           |
| --------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------- |
| [`code`](https://git.io/fAZ1Q) [`live`](https://codesandbox.io/s/github/fanduel-oss/refract/tree/master/examples/routing/callbag) | [`code`](https://git.io/fAZ1y) [`live`](https://codesandbox.io/s/github/fanduel-oss/refract/tree/master/examples/routing/most) | [`code`](https://git.io/fAZ1P) [`live`](https://codesandbox.io/s/github/fanduel-oss/refract/tree/master/examples/routing/rxjs) | [`code`](https://git.io/fAZ1K) [`live`](https://codesandbox.io/s/github/fanduel-oss/refract/tree/master/examples/routing/xstream) |

In this example, a set of tabs are rendered to the screen, with the currently active tab stored in React state.

### Aperture

Two sources are observed in this example:

* The `setActiveTab` callback function.
* The `window.popstate` event.

In addition, a single event is fired when the `aperture` initiates, which sets the initial state to `initialProps.activeTab`.

All three are simply mapped to objects with the desired structure, and merged into a single stream.

### Handler

If the effect's type is `NAVIGATION`, the `handler` calculates the new browser url, and pushes it to `window.history`.

If the effect's type is `STATE`, it calls `setActiveTab` with the new state.

### Result

The end result is a set of tabs whose state is pushed to the browser url as a side-effect.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://refract.js.org/examples/routing.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.