Glossary of terms

This is a new section of the documentation and it's missing a lot of terms! Please submit a pull request or an issue with a term that you think should be explained here.

Header

Also known as navigation header, navigation bar, navbar, and probably many other things. This is the rectangle at the top of your screen that contains the back button and the title for your screen. The entire rectangle is often referred to as the header in React Navigation.

Screen component

A screen component is a component that we use in our route configuration.

const AppNavigator = createStackNavigator(
  {
    Home: {
      screen: HomeScreen, // <----
    },
    Details: {
      screen: DetailsScreen, // <----
    },
  },
  {
    initialRouteName: 'Home',
  }
);

The suffix Screen in the component name is entirely optional, but a frequently used convention; we could call it CasaPantalla and this would work just the same.

We saw earlier that our screen components are provided with the navigation prop. It's important to note that this only happens if the screen is rendered as a route by React Navigation (for example, in response to this.props.navigation.navigate). For example, if we render DetailsScreen as a child of HomeScreen, then DetailsScreen won't be provided with the navigation prop, and when you press the "Go to Details... again" button on the Home screen, the app will throw one of the quintessential JavaScript exceptions "undefined is not an object".

class HomeScreen extends React.Component {
  render() {
    return (
      <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
        <Text>Home Screen</Text>
        <Button
          title="Go to Details"
          onPress={() => this.props.navigation.navigate('Details')}
        />
        <DetailsScreen />
      </View>
    );
  }
}

→ Run this code

The "Navigation prop reference" section goes into more detail on this, describes workarounds, and provides more information on other properties available on this.props.navigation.

Navigation Prop

This prop will be passed into all screens, and it can be used for the following:

• dispatch will send an action up to the router
• state is the current route for the screen
• getParam is a helper to access a param that may be on the route
• navigate, goBack, etc are available to dispatch actions in a convenient way

Navigators can also accept a navigation prop, which they should get from the parent navigator, if there is one.

For more details, see the "Navigation prop document".

Navigation State

The state of a navigator generally looks something like this:

{
  "key": "StackRouterRoot",
  "index": 1,
  "routes": [
    { "key": "A", "routeName": "Home" },
    { "key": "B", "routeName": "Profile" }
  ]
}

For this navigation state, there are two routes (which may be tabs, or cards in a stack). The index indicates the active route, which is "B".

Route

Each route is a piece of navigation state which contains a key to identify it, and a "routeName" to designate the type of route. It can also contain arbitrary params:

{
  "key": "B",
  "routeName": "Profile",
  "params": { "id": "123" }
}

Child Navigation State

When composing navigators, it is possible for a route to be a navigation state. It would look like this:

{
  key: 'B',
  routeName: 'Profile',
  params: { id: '123' },
  index: 1,
  routes: [ {...}, {...} ]
}