I have a calendar section in my app where I want to be able to swipe right or left to go to the next or previous day.
I know that you can use createMaterialTopTabNavigator from React Navigation to do something similar, but I'm not sure if it would work in this specific scenario (where I would have an infinite number of screens and wouldn't be able to predefine them).
I also considered using react-native-gesture-handler's Swipeable component to navigate to the next/previous day screen on a left/right swipe but I'm not sure if this is the easiest/best way to approach this problem.
As you mentioned, you can use Tabs or Swipable. There are some other options like using <ifaram> or <WebView> and using a web URL instead of RN components but it's can be tricky and hard to manipulate.
As a simple solution, you can use carousels instead of using multi screen defining navigation. It's very simple. assume that your screens are an image in an image gallery and you can swipe left/right.
There are many libraries, one of the best ones is: react-native-snap-carousle
Take a look at it's example:
import Carousel from 'react-native-snap-carousel';
export class MyCarousel extends Component {
_renderItem = ({item, index}) => {
return (
<View style={styles.slide}>
<Text style={styles.title}>{ item.title }</Text>
</View>
);
}
render () {
return (
<Carousel
ref={(c) => { this._carousel = c; }}
data={this.state.entries}
renderItem={this._renderItem}
sliderWidth={sliderWidth}
itemWidth={itemWidth}
/>
);
}
}
So you can pass a screen/page as _renderItem to the Carousel
Related
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
Inside my StackNavigator, one of the components includes web content with a long loading time. However, this screen will only be shown late in my navigation flow.
How can I use this time to render my component in the background before finally switching to it?
I couldn't find anything comparable to ReactDOM.render in React Native that would allow me to render it manually.
I am not aware of any option in react-navigation to preload a screen that is not displayed, except maybe when the screen is part of a tab navigator.
Depending on what is slowing down the rendering, you might be able to do some actions in the first screen and later pass the results to the second screen using a navigation parameter.
For instance, if you are fetching data from an api in the second screen, you could fetch this data in the first screen and pass it to the second one:
this.props.navigation.navigate('SecondScreen', { data: this.data });
If it is a component, you could also try to build it in the first screen and pass it in the same fashion:
this.props.navigation.navigate('SecondScreen', { component: this.component });
If you are rendering a WebView in the second screen, what can help is to render the WebView in the first screen too, but with no width or height. The WebView will not be displayed but the website data will be fetched and cached, making the real render more efficient:
render() {
return (
<View>
<WebView source={{ uri: 'https://github.com/facebook/react-native' }} style={{ height: 0, width: 0 }} />
{this.renderCurrentScreen()}
</View>
);
}
For the case of this question let's say I'm building Medium as a React Native app, specifically the screen where you read a story.
This is a long screen, with different types of content appearing as you scroll down. The title, the author information, the content (paragraphs, images, videos, etc), some meta information at the end, social features like comments, etc.
What's the recommended way to build a view like this? ScrollView doesn't seem performant enough especially if there were videos or other media types that needed to be loaded within the content. ListViews seem like they are the more performant option but don't seem like they are designed for this use-case.
Has anyone else faced this challenge? What's the best way to approach it?
<ScrollView> renders all its children first. So, let say you have thousands of elements(medium articles), <ScrollView> will first render all of them, which is pretty much slow and is visible.
For these cases, you can use <FlatList>, which renders the child when it enters the viewport. So, it is performant.
You can refer <FlatList> documentation here: https://facebook.github.io/react-native/docs/flatlist
I had a similar problem for one screen in my app where there were various categories of components involved, for my case <FlatList> worked very well, performance was also up-to the mark.
Solution
Example.js
import React, { Component } from "react";
import { FlatList } from "react-native";
export default class Example extends Component {
constructor(props) {
super(props);
this.state = {
showProgress: false,
content: [{}, {}, {}] // list of objects
};
}
onRefresh() {
this.setState({ showProgress: true });
// call methods here to load new data, once loaded make sure to reset the loading state to false
this.setState({ showProgress: false });
}
showParagraph() {
return <React.Fragment>{/* Your paragraph */}</React.Fragment>;
}
showVideo() {
return <React.Fragment>{/* Your Videos */}</React.Fragment>;
}
showAudio() {
return <React.Fragment>{/* Your Audio */}</React.Fragment>;
}
renderItem(item) {
return (
<React.Fragment>
{item.isVideo ? showVideo() : showParagraph()}
</React.Fragment>
);
}
NoDataMessage() {
return <React.Fragment>{/* Empty screen message goes here */}</React.Fragment>;
}
render() {
return (
<FlatList
data={this.state.content}
keyExtractor={(item, index) => index.toString()}
renderItem={({ item }) => this.renderItem(item)}
onRefresh={() => this.onRefresh()}
refreshing={this.state.showProgress}
ListEmptyComponent={this.NoDataMessage()}
/>
);
}
}
read more about props from here, also you can make an infinite news feed like facebook home page check this React native infinite scroll with flatlist
hope this helps..!
I'd like to have a context menu triggered on long press different places using React Native.
I.e. in a dialer like the default dailer. You can long-click on any contact and get a 'copy number' menu. And also you can long-click on the name of the person once you've opened their 'contact card'.
The straight-forward way needs a lot of copy-pasted boilerplate, both components and handlers.
Is there a better pattern for doing this?
All Touchable components (TouchableWithoutFeedback, TouchableOpacity etc.) has a property called onLongPress. You can use this prop to listen for long presses and then show the context menu.
To eliminate code mess and doing lots of copy paste you can separate your context menu as a different component and call it when the long press happen. You can also use an ActionSheet library to show the desired options. React native has a native API for iOS called ActionSheetIOS. If you get a little bit more experience in react and react-native you can create a better logic for this but I'm going to try to give you an example below.
// file/that/contains/globally/used/functions.js
const openContextMenu = (event, user, callback) => {
ActionSheetIOS.showActionSheetWithOptions({
options: ['Copy Username', 'Call User', 'Add to favorites', 'Cancel'],
cancelButtonIndex: [3],
title: 'Hey',
message : 'What do you want to do now?'
}, (buttonIndexThatSelected) => {
// Do something with result
if(callback && typeof callback === 'function') callback();
});
};
export openContextMenu;
import { openContextMenu } from './file/that/contains/globally/used/functions';
export default class UserCard extends React.Component {
render() {
const { userObject } = this.props;
return(
<TouchableWithoutFeedback onLongPress={(event) => openContextMenu(event, userObject, () => console.log('Done')}>
<TouchableWithoutFeedback onLongPress={(event) => openContextMenu(event, userObject, () => console.log('Done'))}>
<Text>{userObject.name}</Text>
<Image source={{uri: userObject.profilePic }} />
</TouchableWithoutFeedback>
</TouchableWithoutFeedback>
);
}
}
Similarly as the previous answer combine onLongPress with imperative control for popup menu - something like
<TouchableWithoutFeedback onLongPress={()=>this.menu.open()}>
<View style={styles.card}>
<Text>My first contact name</Text>
<Menu ref={c => (this.menu = c)}>
<MenuTrigger text="..." />
<MenuOptions>
// ...
</MenuOptions>
</Menu>
</View>
</TouchableWithoutFeedback>
When it comes to a lot of boilerplate - in React you can do your own components that you can reuse everywhere thus reducing boilerplate (and copy&paste)
See full example on https://snack.expo.io/rJ5LBM-TZ
My Problem is that I would like to navigateBack() from the BountyDetailsScreen to the LoyaltyScreen, but the navigateBack() function call does not trigger any action. When I log the function it says:
The only thing I notice is, that the navigationStack is empty. When I do the same with the navigateTo function it is working, but then I have a messed up navigation stack.
In my LoyaltyScreen.js I am displaying a ListView. It is a RN ListView (not imported from shoutem).
LoyaltyScreen.js
renderRow(bounty) {
return (
<ListBountiesView
key={bounty.id}
bounty={bounty}
onDetailPress={this.openDetailsScreen}
redeemBounty={this.redeemBounty}
/>
);
}
ListBountiesView.js
The ListBountiesView renders each ListView Row and opens a Detail Screen when clicked on the Row.
render() {
const { bounty } = this.props;
return (
<TouchableOpacity onPress={this.onDetailPress}>
{bounty.type == 0 ? this.renderInShopBounty() : this.renderContestBounty()}
<Divider styleName="line" />
</TouchableOpacity>
);
}
BountyDetailsScreen.js
In the BountyDetailsScreen I display detailed information and would like to navigateBack() to the Loyalty Screen when I press a button.
<Button styleName="full-width" onPress={() => this.onRedeemClick()}>
<Icon name="add-to-cart" />
<Text>Einlösen</Text>
</Button>
onRedeemClick() {
const { bounty, onRedeemPress } = this.props;
onRedeemPress(bounty);
navigateBack();
}
navigateBack is an action creator. You need to map it to props and read it from props in your redeemClick function. Just executing the imported action creator won't do anything since it's not connected to Redux.
Here's an example of you map it to props:
export default connect(mapStateToProps, { navigateBack })(SomeScreen));
Here's how you use it:
const { navigateBack } = this.props;
navigateBack();
I can see that airmiha's answer is what you're looking for, but I just wanted to add onto it.
You can also use hasHistory to set up your #shoutem/ui NavigationBar (if you're using it) with a simple back button that utilises navigateBack().
<NavigationBar
styleName="no-border"
hasHistory
title="The Orange Tabbies"
share={{
link: 'http://the-orange-tabbies.org',
text: 'I was underwhelmed by The Orange Tabbies, but then I looked at that
sweet, sweet back button on the Nav Bar.
#MakeNavBarsGreatAgain',
title: 'Nevermind the cats, check the Nav Bar!',
}}
/>
You can find more examples with the NavigationBar component here.