I'm using the TabView from the React-Native and as the part of this i'm using the two states for two different objects as shown below.
const [routes, setRoutes] = React.useState([]);
const [sceneMap, setSceneMap] = React.useState({});
I'm calling a function inside the useEffect hook whenever the TabView gets the focus. Also inside this hook itself i'm changes/reassigning the both of the states with the new values as shown below
React.useEffect(() => {
// Return the function to unsubscribe from the event so it gets removed on unmount
return navigation.addListener('focus', async () => {
const dynamicTabsResponse = await getTabsDynamically();
let response;
if (dynamicTabsResponse != null) {
response = await getRoutes(dynamicTabsResponse);
**setRoutes(response);**
const scenes = await getScenes(dynamicTabsResponse)
newSceneMap = await getSceneMap(response, scenes)
**setSceneMap({...newSceneMap});**
}
});
}, []);
This is my return function:
if (routes.length > 0 && Object.keys(newSceneMap).length > 0) {
return (
<TabView
navigationState={{index, routes}}
renderScene={SceneMap(sceneMap)}
onIndexChange={setIndex}
initialLayout={initialLayout}
/>
);
} else {
console.log( Object.keys(newSceneMap))
console.log("routes length", routes.length)
return null
}
The problem is as soon as the first state gets update the re-render of the UI is happening and its causing the error, since my UI needs the updated state of the second one as well. How can i inform React-Native not to re-render until both the states get update? Is there a way to do like this or i'm implementing in a wrong way? Please suggest
Just to explain more consider the output below:
When i restart the app the values of Routes and Array is as below:
1. routes length inside if 2
2. inside if Array [
"NEWS",
"CRIME",
]
When go other screen and check the check box and come to Tabscreen, the output is as below:
1. routes length inside if 3
2. inside if Array [
"NEWS",
"CRIME",
]
As i can see from the 2nd output, the state of the Routes has been updated to 3(Which is causing the re-render), but not the state of the Array. Due to which TabView is displaying/throwing the error
Error:
Check the render method of `SceneComponent`.,
in SceneComponent (created by SceneView)
in RCTView (created by SceneView)
in SceneView (created by Pager)
in RCTView (at createAnimatedComponent.js:233)
in AnimatedComponent(Component) (created by PanGestureHandler)
in PanGestureHandler (created by Pager)
in Pager (created by TabView)
in RCTView (created by TabView)
in TabView (at NewsScreen.js:73)
in NewsScreen (at SceneView.tsx:98)
in StaticContainer
in StaticContainer (at SceneView.tsx:89)
in EnsureSingleNavigator (at SceneView.tsx:88)
in SceneView (at useDescriptors.tsx:125)
in RCTView (at BottomTabView.tsx:38)
in SceneContent (at BottomTabView.tsx:122)
in RCTView (at ResourceSavingScene.tsx:44)
in RCTView (at ResourceSavingScene.tsx:27)
in ResourceSavingScene (at BottomTabView.tsx:117)
in RCTView (at screens.native.js:132)
in ScreenContainer (at BottomTabView.tsx:101)
in RCTView (at BottomTabView.tsx:100)
in SafeAreaProviderCompat (at BottomTabView.tsx:99)
in BottomTabView (at createBottomTabNavigator.tsx:41)
in BottomTabNavigator (at BottomTabNavigator.js:22)
in BottomTabNavigator (at SceneView.tsx:98)
in StaticContainer
in StaticContainer (at SceneView.tsx:89)
in EnsureSingleNavigator (at SceneView.tsx:88)
in SceneView (at useDescriptors.tsx:125)
in RCTView (at CardContainer.tsx:190)
in RCTView (at CardContainer.tsx:189)
in RCTView (at Card.tsx:526)
in RCTView (at createAnimatedComponent.js:151)
in AnimatedComponent (at Card.tsx:508)
in PanGestureHandler (at Card.tsx:501)
in RCTView (at createAnimatedComponent.js:151)
in AnimatedComponent (at Card.tsx:497)
const Hello = () => {
let response = [{one:"two"}]
let newSceneMap = {
name:"sdfvsdf"
}
const [routesAndsceneMap, setIt] = React.useState({
routes:[{one:"three"}],
sceneMap:{
name:"sdfvds"
}
});
const changeit = () => {
setIt({...routesAndsceneMap,routes:[...response],sceneMap: {...newSceneMap}})
}
return (
<div>
<h1>Hello {routesAndsceneMap.routes[0].one} {routesAndsceneMap.sceneMap.name}!</h1>
<button onClick={changeit}>Click</button>
</div>
)};
You can check here how it works For working see this link https://stackblitz.com/edit/react-p7jrjv?file=Hello.js
You have added two different useState instead try to combine it into one as i have done and change it together in just one set function on button click it changes two properties together