Reducer RecipeScreen RecipeScreenContainer Action.js OnPress
Hi,ı have a problem with on handleSavePress,when first onPress its not saving into savedRecipes,when ı clicked second its saved but ı onpress again its not deleting and my icon is not turning,can you help me about this.Thanks
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First-of-all I apologise because I'm new to this concept of redux haha so bare with me here :)
I have implemented a very simple redux in my app
I have one screen here ListAnItem
Here there is a button.
Add size when pressing this they get navigated to another screen called SizeSelector
SizeSelector
here there is a button called dispatch size when they press this button it runs the following.
dispatch({type: "ADD_SIZE", payload: size })
this works perfectly with useSelector.
once this dispatch has been run I use navigation.goBack() to send the user back to the ListAnItem screen.
but once they come to this screen I want to add this useSelector redux state value to a useState hook something like this;
const [sizeState, setSizeState] = React.useState(null)
how can I change this state the minute something has been added to useSelector value of ADD_SIZE.
if that makes sense 😂.
Thanks,
Arnav.
I put the props I caught with redux in componentWillMount to a variable and updated the state.
This is the Image 1:
I update the textInput on the page as shown in the image. But only when it should update the contact array in state. The company.contract in Props is also being updated.
This is the Image 2:
How to prevent Props from updating?
Here are the screen and log message:
I would like to know if it's possible to set the state to the initial state values whenever we press back the button in the tabBar ? At the moment, when I leave the tabBar and come back after a few navigation in the app, the infos that the user enter in TextField persist.
Thanks !
You could use React hooks to achieve similar results to lifecycle methods in class functions.
The useEffect method runs on component render. You can set the state in there.
const [currentState, setCurrentState] = useState(null);
useEffect(()=>{
// This will run after 1st render
setCurrentState("");
},[]);
I have a large long image with a few inputs at the bottom in my react native view. When the view loads I want it to be "scrolled" to the bottom of the page -- all the examples I can find online are triggered because of some event that the user does.
I want to call scrollToEnd() but I'm not sure where in the lifecycle the ref will actually be set -- anyone have ideas?
Use scrollToEnd this way. It will take to the bottom of ScrollView
<ScrollView
ref={ref => this.scrollView = ref}
onContentSizeChange={(contentWidth, contentHeight)=>{
this.scrollView.scrollToEnd({animated: true});
}}>
I am not clear with your question but
With react-native Image component we have onLoad prop. I think this is what you are looking for.
try something like:
<Image source={{uri...}} onLoad={(e)=>this.handleImageLoaded(e)}/>
then inside handleImageLoaded method you can use scrollToEnd() with some ref as per your code.
also there are other useful props like onLoadStart/End check here
https://facebook.github.io/react-native/docs/image
Or if you are just waiting for the view to render then to scroll
for that I think componentDidAppear() lifecycle method, if using react-native -navigation by wix
or with react-navigation
willFocus, willBlur, didFocus and didBlur events for the component render cycle.. explained here
https://reactnavigation.org/docs/en/navigation-prop.html#addlistener-subscribe-to-updates-to-navigation-lifecycle
I am new in React Native ...just want ask nub question, my App wont triggered componentWillMount and componentDidMount when navigate back to other page,
I use react-native-router-flux for navigator
componentWillMount() {
this.props.searchRequest();
}
exp: I have homescreen and categories, from home I want go to categories: on categories I have that code, but sometime when I back to previouse page (homescreen) and back again on categories componentWillMount not triggered sometime,
I think my categories scene not unmounted
We can detect props change with
componentWillReceiveProps()
but we need set state to accommodate new props value,