I'm using React Native with NativeBase and would like to make the labels of my Picker more complicated than just one plain string of text.
But is it even possible to pass elements as the label, say multiple child elements wrapped in a single top-level element?
Or do Pickers only support plain text as labels?
As requested by bennygenel, here's a version of what I've tried:
export default class ThingPicker extends React.Component {
render() {
const {
initialThing,
things,
onThingChanged,
} = this.props;
const orderedThings = things.sort();
return (
<Picker
selectedValue={initialThing}
onValueChange={onThingChanged}>
{buildThingItems(orderedThings)}
</Picker>
);
}
}
function buildThingItems(orderedThings) {
let items = orderedThings.map(th => {
const it = th === "BMD" ? (<Text key={th} label={"foo"} value={"bar"}}>Hello</Text>)
: (<Picker.Item key={th} label={th} value={th} />);
return it;
});
}
Yes! It is possible, it just might not look very "right" for React/JSX code. Just create the elements you need and assign them to the label field:
function buildThingItems(orderedThings) {
let items = orderedThings.map(th => {
const it = (<Picker.Item
key={th}
label={currency === "BMD" ? (<Text>Hello</Text>) : th}
value={th} />);
return it;
});
}
Related
I have the data from contentful, the data is formatted like this and is converted using #contentful/rich-text-react-renderer with this conversion options. By calling the codes below to perform the conversion
import { documentToReactComponents } from '#contentful/rich-text-react-renderer';
const convert = (document: any) => {
const nodes = documentToReactComponents(document?.fields?.html, contentfulToReactnative);
if (nodes && Array.isArray(nodes)) {
const newNodes = nodes.map((component, index) => {
if (index + 1 === nodes.length) {
return component;
}
return <View key={uuid()}>{component}</View>;
});
return newNodes;
}
return nodes;
};
with that, I got arrays of <ForwardRef /> like this
[<ForwardRef />, <ForwardRef(Text) allowFontScaling={false}></ForwardRef(Text)>]
the question is, how should I display ForwardRefs in react native. By doing {elements} (elements is the variable holding that array) won't work.
I don't know yet if these ForwardRefs are the things to display.
Now when these tags are in component file how does one map through various values.
Example
1. <Image source = require("")/>
2. const { sound } = await Audio.Sound.createAsync(require("../../assets/sounds/slack.mp3")
You can map like this:
const { sound } = await Audio.Sound.createAsync(require("../../assets/sounds/slack.mp3")
return sound.map((item, index) => (
<YourComponent key={index}>{item.value}</YourComponent>
))
I have a case where I need to export two child components and use individually.
Much Desired outcome (Extremely simplified):
Controls.js:
const Controller = ( props ) => {
const ControlBoxes = () => {
return(<Button>Move around!</Button>)
}
const MoveableBox = () => {
return(<View>I will be moved! </View>)
}
return {ControlBoxes, MoveableBox}
}
export default Builder
Canvas.js:
import Controller from './controls'
const boxScaleMove = boxes.map((box, index) => {
return (
<Bulilder.MoveableBox key={box.id} box={box}/>
)
}
const boxController = boxes.map((box, index) => {
return (
<Bulilder.ControlBoxes key={box.id} box={box}/>
)
}
return (
...
{boxController}
...
...
{boxScaleMove}
...
)
Any idea how I can achieve this or am I missing something fundamental? The main issue is that I want to avoid resorting to useContext (due to performance reasons in the case of a lot of boxes rendered) and be able to share variables and states between MoveableBox-component and ControlBoxes-component via Controller -parent.
Any help would be greatly appreciated.
You could use the compound component and use a lower level context to avoid re-rendering of the whole tree and share states across your components that way, below I would ilustrate a basic example of how that would work.
const RandomContext = createContext();
export default function Controller({children, ...rest}) {
const [randomState, setRandom] = useState(0);
return (
<RandomContext.Provider value={{ randomState, setRandom }}>
<div {...rest}>{children}</div>
</RandomContext.Provider>
);
}
Controller.ControlBoxes = function (props) {
const { setRnadom } = useContext(RandomContext);
return (
<Button onClick={() => setRandom(2)} {...props}>Move around!</Button>
);
};
Controller.MoveableBox = function (props) {
const { randomState } = useContext(RandomContext);
return randomState ? <View {...props}>I will be moved!</View> : null;
};
And you would use it as:
<Controller>
<Controller.ControlBoxes />
<Controller.MoveableBox />
<Controller>
In the compound components pattern we are leveraging the fact that in javascript when you declare a function you create a function/object combo. Therefor Controller function is both a function and an object, so we can assign properties the the object part of that combo, properties which are in our case ControlBoxes and MoveableBox which are functions themselves.
NOTE you should probably assign named function the the properties of that object, it's easier to debug if the case needed.
Example.Function = function ExampleFunction(props) {
return "Example";
};
I have two different components one is CategoryList which is a flatlist and regionlist is a section list. I would like to display the CategoryList first and when item clicked the regionlist will show however I m not sure why it is not working. (I use context to store the state)
{!isToggle ? (
<CategoryList></CategoryList>
) : (
<RegionList style={styles.regionListStyle}></RegionList>
)}
I also create a button to see if it is a problem about the context but it is not.
const ToggleContext = createContext(true);
export const useToggle = () => {
return useContext(ToggleContext);
};
export function ToggleProvideData({children}) {
const [isToggle, setToggle] = useState(true)
return <ToggleContext.Provider value={{isToggle,setToggle}}>
{children}
</ToggleContext.Provider>;
}
I just wonder conditional render is it not working for flatlist?
UPDATE: I tried create a state to store the useContext isToggle but it only appears for like 1 sec
I guess isToggle as a boolean variable, hence you can use the below code for rendering conditionally
{ (isToggle === true) &&
<CategoryList></CategoryList>
}
{ (isToggle === false) &&
<RegionList style={styles.regionListStyle}></RegionList>
}
I've created some components in a for loop and push them to an array. Can i get any component from this array to change its props -like title ?
fields = [];
for (let i = 0; i < assets.fieldNames[assets.systemLang].length; i++) {
fields.push(
<InfoField
handlePress={() => this.fieldPressed(i)}
key={i}
title={assets.fieldNames[assets.systemLang][i]}
value="" />
);
};
.....
<View style={styles.infoFields}>
{
fields
}
</View>
and i have a function that i need something like this
changeComponentTitle = () => {
fields[indexForComponent].props.title = "new Title"
}
You'll need to make sure that you trigger a re-render in some way after you make the update (perhaps by putting fields in a state variable and calling setState as mentioned in the comments) but you can use cloneElement to essentially update a single prop of an existing element: https://reactjs.org/docs/react-api.html#cloneelement
changeComponentTitle = () => {
fields[indexForComponent] = React.cloneElement(fields[indexForComponent], {title: "new Title"});
}