The React-Native Navigator component maintains a "stack" of components, which constitute it's navigation history. If some of those components bind to native modules, for instance the react-native-camera library, of which expect to be considered a singleton (that is, exist at most once at a time), what would be the best way to manage that requirement? My first stab would be to only allow pop() from that singleton component, but I would like something less restrictive.
Related
Wondering if there's a simple way to overlay react-navigation's Stack and MaterialTopTabNavigator components within individual screens. I need to overlay both when displaying components such as loading overlays and dialog/prompt components.
I understand I could define these components within the same root file as the navigation, however this means I have to track the state of the dialog within redux or some other shared state, which I would prefer to avoid in an effort to be more declarative/functional.
Can't find any good solutions, and I'm combing through react-navigation's source code, but if someone else has already solved this it would save me a lot of time. Thanks!
Edit: I also don't want to use react-native's modal or react-native-modal. Would like to implement a custom component myself.
Hello Guys is this a good stuff in React native Environment I create all Scenes as Components and being rendering it without using react navigator or something like that ?
It depends on the size of app. If it's a very simple ui and functionality then it's ok but not good. Bu if it has so much screens and have complex functionalities, then break it down to different screens and use navigation. In fact it would be a good practice to use different screens and navigation. It also is good practice for memory management.
Context:
I am using ReactNavigation to implement the navigation on my React Native app. All my views so far have no styles defined for them, and look just fine if I access them directly, without any routing. When accessed through the library's StackNavigator, however, they get extremely distorted, to the point where all components collapse into one. I suspect this is happening due to the cascading of the navigator's styling.
Question:
Is there any way to disable style cascading for a particular component in ReactNative?
I am implementing android application using react-native and redux. My container component is updating frequently but props which I am passing to child stateless component not changing, but it still re-render all the time. How can I prevent this re-render? I know that I can use shouldComponentUpdate, but then I need to check there all properties.
This is exactly why React doesn't do this for you. It would need to check all the properties and their children (and descendants). This could be a lot of work.
If you use React-Redux, just connect the component to whatever data it needs and it shouldn't rerender, because Redux makes different assumptions about your data. In particular, it assumes you use immutable objects everywhere, which means it doesn't have to check children (or descendants).
Without React-Redux, you will need to implement shouldComponentUpdate, but if you use immutable data, you can implement a generic function to do a shallow compare and use it in all your components. If you do not use immutable data everywhere, you'll need to either use a deep comparison, or to optimize, implement shouldComponentUpdate on a component-by-component basis to do specific checks.
This is a big reason why React-Redux is used.
That's how React works. If a parent component re-renders, all of its children will re-render, and then React will diff the virtual DOM output and see what actually needs to be updated in the real UI. This process happens even if the props being passed to a child component haven't changed. And yes, shouldComponentUpdate is the right solution here, but that can't be used with functional components as far as I know, since they have no lifecycle methods.
If you want to prevent re-rendering, you'll probably need to convert those functional components into class components, and either implement shouldComponentupdate yourself, or have them extend React.PureComponent if you're using React 15.3.
Just look through fb's document.
What is different between navigator and navigatorIOS in react-native?
There used to be a comparision between the two in the official docs. Not sure why it is removed since 0.31. You can still get it from google the cached version though:
Navigator Comparison
The differences between Navigator and NavigatorIOS are a common source
of confusion for newcomers.
Both Navigator and NavigatorIOS are components that allow you to
manage the navigation in your app between various "scenes" (another
word for screens). They manage a route stack and allow you to pop,
push, and replace states. In this way, they are similar to the html5
history API. The primary distinction between the two is that
NavigatorIOS leverages the iOS UINavigationController class, and
Navigator re-implements that functionality entirely in JavaScript as a
React component. A corollary of this is that Navigator will be
compatible with Android and iOS, whereas NavigatorIOS will only work
on the one platform. Below is an itemized list of differences between
the two.
Navigator #
Extensive API makes it completely customizable from JavaScript.
Under active development from the React Native team.
Written in JavaScript.
Works on iOS and Android.
Includes a simple navigation bar component similar to the default NavigatorIOS bar: Navigator.NavigationBar, and another with
breadcrumbs called Navigator.BreadcrumbNavigationBar.
See the UIExplorer demo to try them out and see how to use them. Currently animations are good and improving, but they are still less
refined than Apple's, which you get from NavigatorIOS.
You can provide your own navigation bar by passing it through the navigationBar prop.
NavigatorIOS #
Small, limited API makes it much less customizable than Navigator in its current form.
Development belongs to open-source community - not used by the React Native team on their apps. A result of this is that there is
currently a backlog of unresolved bugs, nobody who uses this has
stepped up to take ownership for it yet.
Wraps UIKit, so it works exactly the same as it would on another native app. Lives in Objective-C and JavaScript. Consequently, you
get the animations and behaviour that Apple has developed. iOS only.
Includes a navigation bar by default; this navigation bar is not a React Native view component and the style can only be slightly
modified.
Based on my experience, navigatorIOS is pretty buggy for now and I would suggest using Navigator instead. If you take a look at the Facebook F8 app, they were using Navigator rather than navigatorIOS.
Navigator is a transition between different scenes in your app, it can be regarded as an animation.
NavigatorIOS wraps UIKit navigation, it will push or pop a controller and behave more like an Native navigation.