Update Child state from Parent using Context in React - arrays

Question

I have a few buttons and "view all" button. The individual buttons load the coresponding data of that index or will show all the data by clicking the "view all" button. Problem I am running into is when I click my "view all" button in the parent it's not updating the state in the child component. On mounting it works as normal but on event handler in the "view all" it doesn't update. Any thoughts on where I am going wrong here?
JS:
...
const Context = createContext(false);
const useStyles = makeStyles((theme) => ({
root: {
display: "flex",
"& > *": {
margin: theme.spacing(1)
}
},
orange: {
color: theme.palette.getContrastText(deepOrange[500]),
backgroundColor: deepOrange[500],
border: "4px solid black"
},
info: {
margin: "10px"
},
wrapper: {
display: "flex"
},
contentWrapper: {
display: "flex",
flexDirection: "column"
},
elWrapper: {
opacity: 0,
"&.active": {
opacity: 1
}
}
}));
const ToggleItem = ({ id, styles, discription }) => {
const { activeViewAll, handleChange } = useContext(Context);
const [toggleThisButton, setToggleThisButton] = useState();
const handleClick = () => {
setToggleThisButton((prev) => !prev);
handleChange(discription, !toggleThisButton);
};
return (
<>
<Avatar
className={toggleThisButton && !activeViewAll ? styles.orange : ""}
onClick={handleClick}
>
{id}
</Avatar>
<p>{JSON.stringify(toggleThisButton)}</p>
</>
);
};
const ToggleContainer = ({ className, selected }) => {
return (
<div className={className}>
{selected.map((item, idx) => (
<div key={idx}>Content {item}</div>
))}
</div>
);
};
export default function App() {
const data = ["first", "second", "third"];
const classes = useStyles();
const [selected, setSelected] = useState([]);
const [activeViewAll, setActiveViewAll] = useState(false);
useEffect(() => {
setActiveViewAll(true);
setSelected([...data]);
}, []);
const handleChange = (val, action) => {
let newVal = [];
if (activeViewAll) {
selected.splice(0, 3);
setActiveViewAll(false);
}
if (action) {
newVal = [...selected, val];
} else {
// If toggle off, then remove content from selected state
newVal = selected.filter((v) => v !== val);
}
console.log("action", action);
setSelected(newVal);
};
const handleViewAll = () => {
console.log("all clicked");
setActiveViewAll(true);
setSelected([...data]);
};
return (
<Context.Provider value={{ activeViewAll, handleChange }}>
<div className={classes.wrapper}>
<Avatar
className={activeViewAll ? classes.orange : null}
onClick={handleViewAll}
>
<span style={{ fontSize: "0.75rem", textAlign: "center" }}>
View All
</span>
</Avatar>
{data.map((d, id) => {
return (
<div key={id}>
<ToggleItem id={id} styles={classes} discription={d} />
</div>
);
})}
</div>
<div className={classes.contentWrapper}>
<ToggleContainer styles={classes} selected={selected} />
</div>
</Context.Provider>
);
}
Codesanbox:
https://codesandbox.io/s/72166087-forked-jvn59i?file=/src/App.js:260-3117

Answer 1

Issue
The issue seems to be that you are mixing up the management of the boolean activeViewAll state with the selected state.
Solution
When activeViewAll is true, pass the data array as the selected prop value to the ToggleContainer component, otherwise pass what is actually selected, the selected state.
Simplify the handlers. The handleViewAll callback only toggles the view all state to true, and the handleChange callback toggles the view all state back to false and selects/deselects the data item.
function App() {
const data = ["first", "second", "third"];
const classes = useStyles();
const [selected, setSelected] = useState([]); // none selected b/c view all true
const [activeViewAll, setActiveViewAll] = useState(true); // initially view all
const handleChange = (val, action) => {
setActiveViewAll(false); // deselect view all
setSelected(selected => {
if (action) {
return [...selected, val];
} else {
return selected.filter(v => v !== val)
}
});
};
const handleViewAll = () => {
setActiveViewAll(true); // select view all
};
return (
<Context.Provider value={{ activeViewAll, handleChange }}>
<div className={classes.wrapper}>
<Avatar
className={activeViewAll ? classes.orange : null}
onClick={handleViewAll}
>
<span style={{ fontSize: "0.75rem", textAlign: "center" }}>
View All
</span>
</Avatar>
{data.map((d, id) => {
return (
<div key={id}>
<ToggleItem id={id} styles={classes} discription={d} />
</div>
);
})}
</div>
<div className={classes.contentWrapper}>
<ToggleContainer
styles={classes}
selected={activeViewAll ? data : selected} // pass all data, or selected only
/>
</div>
</Context.Provider>
);
}
In the ToggleContainer don't use the array index as the React key since you are mutating the array. Use the element value since they are unique and changing the order/index doesn't affect the value.
const ToggleContainer = ({ className, selected }) => {
return (
<div className={className}>
{selected.map((item) => (
<div key={item}>Content {item}</div>
))}
</div>
);
};
Update
Since it is now understood that you want to not remember what was previously selected before toggling activeViewAll then when toggling true clear the selected state array. Instead of duplicating the selected state in the children components, pass the selected array in the context and computed a derived isSelected state. This maintains a single source of truth for what is selected and removes the need to "synchronize" state between components.
const ToggleItem = ({ id, styles, description }) => {
const { handleChange, selected } = useContext(Context);
const isSelected = selected.includes(description);
const handleClick = () => {
handleChange(description);
};
return (
<>
<Avatar
className={isSelected ? styles.orange : ""}
onClick={handleClick}
>
{id}
</Avatar>
<p>{JSON.stringify(isSelected)}</p>
</>
);
};
const ToggleContainer = ({ className, selected }) => {
return (
<div className={className}>
{selected.map((item) => (
<div key={item}>Content {item}</div>
))}
</div>
);
};
Update the handleChange component to take only the selected value and determine if it needs to add/remove the value.
export default function App() {
const data = ["first", "second", "third"];
const classes = useStyles();
const [selected, setSelected] = useState([]);
const [activeViewAll, setActiveViewAll] = useState(true);
const handleChange = (val) => {
setActiveViewAll(false);
setSelected((selected) => {
if (selected.includes(val)) {
return selected.filter((v) => v !== val);
} else {
return [...selected, val];
}
});
};
const handleViewAll = () => {
setActiveViewAll(true);
setSelected([]);
};
return (
<Context.Provider value={{ activeViewAll, handleChange, selected }}>
<div className={classes.wrapper}>
<Avatar
className={activeViewAll ? classes.orange : null}
onClick={handleViewAll}
>
<span style={{ fontSize: "0.75rem", textAlign: "center" }}>
View All
</span>
</Avatar>
{data.map((d, id) => {
return (
<div key={d}>
<ToggleItem id={id} styles={classes} description={d} />
</div>
);
})}
</div>
<div className={classes.contentWrapper}>
<ToggleContainer
styles={classes}
selected={activeViewAll ? data : selected}
/>
</div>
</Context.Provider>
);
}