I have a <view> touching which will open a collapsible view. I have used react-native-collapse-view for it (https://www.npmjs.com/package/react-native-collapse-view) I have <text> on top of <view> which is covering it full. I am setting some conditions in onPress event of the <text> element.
Now what I want is if I touch the <text> (obviously I cannot touch view as text is covering it fully), along with onPress event of the <text> the underlaying <view> should also be touched so that it opens the collapsible view.
In short I want to pass the touch event to the parent view in order to complete all work in one touch. I searched and found some content related to onStartShouldSetResponder and pointerEvents but I couldn't get the complete grip as I am a newbie to react native.
in short you need pass function to children for handling events
import React from "react";
class ChildComponent extends React.PureComponent {
render() {
const {handleChildPress} = this.props;
return <Text onPress={handleChildPress}/>;
}
}
class ContainerComponent extends React.PureComponent {
// you need pass this func to children
// =()=> means bind it
handleChildPress=()=>{
console.log('child pressed')
}
render() {
return <ChildComponent handleChildPress={this.handleChildPress}/>;
}
}
export default ContainerComponent
Related
hi everyone i am new to react-native and i have a problem in passing the status from the parent component (HomePage.js) to the daughter component (SecondPage.js). On the parent screen (HomePage)
instead of just having the button, I also have the result of the daughter's status. i.e. on the Homepage I have:
"result is: ooo" and below I have the button. If I click on the button, the SecondPage screen appears with the result "result is:" without passing the value of the state of the parent component "ooo".
in HomePage.js
export default class HomePage extends Component {
static navigation={}
constructor(){
super();
this.state = {alreadyLaunched: null,sid:"ooo"};
}
render(){
return (
<View style={styles.container}>
<SecondPage stato={this.state.sid} />
<Button
onPress={ () => this.props.navigation.navigate('SecondPage')}
title="DETAILE" color="orange"/>
</View>
);
}
}
And in SecondPage.js
export default class SecondPage extends Component {
render(){
return (
<View >
<Text>result is: {this.props.stato}</Text>
</View>
)
}
}
I want to have in the parent screen (HomePage), a button that takes me to the child screen that shows me the result "result is:ooo". how can I solve my problem? because in the parent screen (HomePage) I have the result of the child screen (SeconPage )?
you have two mode of using second page. the first mode is using component in your home page and it's correct.but in the navigation mode you should pass the parameter in this way =>
<Button onPress={ () => this.props.navigation.navigate('SecondPage', {stato: this.state.sid})} title="DETAILE" color="orange"/>
and in the second page =>
result is: {this.props.stato ? this.props.stato : this.props.navigation.state.params.stato}
note:
if you use new version of react navigation instead of (this.props.navigation.state.params.stato) use route.params.stato
I have changed all the TouchableOpacity-components to a custom component so I can add a universal function to all the buttons / clickable views in my application. I call the new component HapticButton.
All the HapticButton-components will contain onPress properties like this:
<HapticButton activeOpacity={1.0} onPress={() => { console.log("button was pressed"); }}>...</HapticButton>
And my HapticButton-class looks like this:
import React from 'react';
import { TouchableOpacity, Text} from 'react-native';
export default class HapticButton extends React.Component {
render() {
return (
<TouchableOpacity activeOpacity={this.props.activeOpacity} style={[this.props.style]} onPress={this.props.onPress}>
{this.props.children}
</TouchableOpacity>
);
}
vibrate() {
// Code that makes a haptic feedback when called
}
};
I succesfully pass on the onPress-property to my new HapticButton-component, but how do I merge together my the this.props.onPress-property with the vibrate()-function so that this gets called every time the HapticButton is pressed?
You can easily merge two function call together as below
<TouchableOpacity onPress={() => {
this.props.onPress();
this.vibrate();
}}>
or you can directly invoke this.props.onPress() in the vibrate function
<TouchableOpacity onPress={this.vibrate} ...
vibrate() {
this.props.onPress();
// Code that makes a haptic feedback when called
}
Not much differences based on your use case between the two ways I've shared, readability wise I think first way is better
Background
Pretty simple question: I want to create a "like" button in RN. To do this I have to separate components which are SVG files. One is just the outline of a heart, the other one is filled.
The screen in which I'm trying to build this button is a Function component so I should use hooks. I know about state but don't know how to properly use it.
What I need
A Touchable Opacity component which holds an onPress method which changes the image component when pressed.
Thanks a lot in advance!
import React ,{useState} from 'react';
import {TouchableOpacity } from "react-native";
export default function Like() {
const [isLiked,setIsLiked]=useState(false) ;
const handleLikePress=()=>{
setIsLiked(!isLiked)
}
return (
<TouchableOpacity onPress={handleLikePress}>
{isLiked? <FilledHeartSVG/>: <OutlineHeartSVG/> }
</TouchableOpacity>
)
}
by default, we are showing an outline of a heart SVG
when press event trigger we are changing isLiked state value
if isLiked is true then show filled heart SVG
if isLiked is false then show outline of a heart SVG
FilledHeartSVG and OutlineHeartSVG is just example use your SVG there
You can do something like below, here i have made a toggle for the text but you can change it to your image component, also the callback prop can be used if you want to use that outside the LikeButton
const LikeButton = ({callback}) => {
const [liked, setLiked] = React.useState(false);
return (
<TouchableOpacity onPress={()=>{
setLiked(!liked);
if(callback)
{
callback();
}
}}>
<Text>{liked?"Liked":"Like"}</Text>
</TouchableOpacity>
);
};
You can tryout this snack which uses icons
https://snack.expo.io/#guruparan/likebutton
I am looking for pointers where I can start from.
I want to create a react native feedback form which can be displayed with .show method.
for eg:
export class FeedbackComponent extends React.component{
show() {
// define this method in a way so that can be called from outside as FeedbackComponent.show()
// which eventually create a new screen with below rendered View
}
render (){
return <View>Feedback Form</View>
}
}
I should be able to use this Component in any other component as
import FeedbackComponent from './FeedbackComponent'
new FeedbackComponent.show()
I would always start with considering the application state. UI in React is updated whenever the State of our components changes.
In your case I would have to think of the parent context in which your feedback form will need to be displayed. In its simplest form, this context will likely be a parent screen-component within which your FeedbackForm component is either shown or hidden.
I've made a Snack of a simple implementation you can find it here: https://snack.expo.io/#stephos_/show-feedback-form
In my case, the App component is the parent screen-component within which we need to render or not render a FeedbackForm Component.
So I would start with adding the relevant state property to the App (parent screen) component like so:
state = {
feedbackFormVisible : false
}
I would then define a method within the same parent class in order to toggle the state when we need to like so:
handleFeedbackFormVisibility = () => this.setState(prevState => ({feedbackFormVisible:!prevState.feedbackFormVisible}))
This handler takes in the previous state in our parent component and toggles the value of the feedbackFormVisible property (i.e. from false to true).
In my case, I call this handler every time we press a Button component like so:
<Button title="Give Feedback" onPress={this.handleFeedbackFormVisibility}/>
You could however trigger the same handler and update the state of the parent component in any other way (i.e. after a timer expires or after a specific scroll point is passed).
The App Component's render method will then decide if the FeedbackForm component should be displayed based on the value of the feedbackFormVisible in our App Component's state. We achieve this by wrapping our FeedbackForm component within an Elvis Conditional within the render method which will return the the appropriate UI (i.e. either with a visible feedback form or not):
{ this.state.feedbackFormVisible ? () : null}
Below the full App component code:
import * as React from 'react';
import { Text, View, StyleSheet, Button } from 'react-native';
import FeedbackForm from './components/FeedbackForm';
export default class App extends React.Component {
state = {
feedbackFormVisible : false
}
handleFeedbackFormVisibility = () => this.setState(prevState => ({feedbackFormVisible:!prevState.feedbackFormVisible}))
render() {
return (
<View style={styles.container}>
<Text style={styles.paragraph}>
This is the App Parent Component
</Text>
{
this.state.feedbackFormVisible ?
(<FeedbackForm />)
: null
}
<Button title="Give Feedback" onPress={this.handleFeedbackFormVisibility}/>
</View>
);
}
}
And below the Feedback Component code (Notice that the shown/hidden logic is actually handled in the parent component not in here):
import * as React from 'react';
import { Text, View, StyleSheet } from 'react-native';
export default class FeedbackForm extends React.Component {
render() {
return (
<View style={styles.container}>
<Text style={styles.paragraph}>
This is the feedback form!
</Text>
</View>
);
}
}
I'm new to react native.
I was using NavigatorIOS but it was too limiting so I'm trying to use Navigator. In NavigatorIOS I can change a view by calling this.props.navigator.push() but it doesn't work in Navigator, it seems to be structured differently. How do I change views in using Navigator?
That's the minimal working navigator - it can do much more (see at the end):
You need your main "navigator" view to render Navigator component
In the Navigator you need to specify how you should render scenes for different routes (renderScene property)
In this "renderScene" method you should render View (scene) based on which route is being rendered. Route is a plain javascript object, and by convention scenes can be identified by "id" parameter of the route. For clarity and separation of concerns I usually define each scene as separate named component and use the name of that components as "id", though it's just a convention. It could be whatever (like scene number for example). Make sure you pass navigator as property to all those views in renderScene so that you can navigate further (see below example)
When you want to switch to another view, you in fact push or replace route to that view and navigator takes care about rendering that route as scene and properly animating the scene (though animation set is quite limited) - you can control general animation scheme but also have each scene animating differently (see the official docs for some examples). Navigator keeps stack (or rather array) of routes so you can move freely between those that are already on the stack (by pushing new, popping, replacing etc.)
"Navigator" View:
render: function() {
<Navigator style={styles.navigator}
renderScene={(route, nav) =>
{return this.renderScene(route, nav)}}
/>
},
renderScene: function(route,nav) {
switch (route.id) {
case "SomeComponent":
return <SomeComponent navigator={nav} />
case "SomeOtherComponent:
return <SomeOtherComponent navigator={nav} />
}
}
SomeComponent:
onSomethingClicked: function() {
// this will push the new component on top of me (you can go back)
this.props.navigator.push({id: "SomeOtherComponent"});
}
onSomethingOtherClicked: function() {
// this will replace myself with the other component (no going back)
this.props.navigator.replace({id: "SomeOtherComponent"});
}
More details here https://facebook.github.io/react-native/docs/navigator.html and you can find a lot of examples in Samples project which is part of react-native: https://github.com/facebook/react-native/tree/master/Examples/UIExplorer
I find that Facebook examples are either to simplistic or to complex when demonstrating how the Navigator works. Based on #jarek-potiuk example, I created a simple app that will switch screens back and forth.
In this example I'm using: react-native: 0.36.1
index.android.js
import React, { Component } from 'react';
import { AppRegistry, Navigator } from 'react-native';
import Apple from './app/Apple';
import Orange from './app/Orange'
class wyse extends Component {
render() {
return (
<Navigator
initialRoute={{screen: 'Apple'}}
renderScene={(route, nav) => {return this.renderScene(route, nav)}}
/>
)
}
renderScene(route,nav) {
switch (route.screen) {
case "Apple":
return <Apple navigator={nav} />
case "Orange":
return <Orange navigator={nav} />
}
}
}
AppRegistry.registerComponent('wyse', () => wyse);
app/Apple.js
import React, { Component } from 'react';
import { View, Text, TouchableHighlight } from 'react-native';
export default class Apple extends Component {
render() {
return (
<View>
<Text>Apple</Text>
<TouchableHighlight onPress={this.goOrange.bind(this)}>
<Text>Go to Orange</Text>
</TouchableHighlight>
</View>
)
}
goOrange() {
console.log("go to orange");
this.props.navigator.push({ screen: 'Orange' });
}
}
app/Orange.js
import React, { Component, PropTypes } from 'react';
import { View, Text, TouchableHighlight } from 'react-native';
export default class Orange extends Component {
render() {
return (
<View>
<Text>Orange</Text>
<TouchableHighlight onPress={this.goApple.bind(this)}>
<Text>Go to Apple</Text>
</TouchableHighlight>
</View>
)
}
goApple() {
console.log("go to apple");
this.props.navigator.push({ screen: 'Apple' });
}
}
I was having the same trouble, couldn't find a good example of navigation. I wanted the ability to control views to go to a new screen but also have the ability to go back to the previous screen.
I used the above answer by Andrew Wei and created a new app then copied his code. This works well but the .push will keep on creating new layers over each other (Apple > Orange > Apple > Orange > Apple > Orange etc.). So I used .pop in the Orange.js file under goApple() instead of .push.
This works like a "back" button now, which was what I was looking for, while teaching how to navigate to other pages.