I want to delete this TODO with or without using a unique key
this is the HOOK code
const [todos, setTodos] = useState([{}])
const [user, setUser] = useState({
id: uuidv4(),
name: '',
email: '',
phone: '',
})
This one is the Function to set Input and delete a todo
const addTodo = (e) => {
e.preventDefault()
setTodos([...todos, user])
console.log(addTodo)
}
console.log(user)
const delTodo = (e, id) => {
e.preventDefault()
console.log(id)
todos.splice(id, 1)
setTodos([...todos])
}
Here These are being mapped
{todos.map((todo) => (
<div>
<li key={todo.id}>
{todo.name}, {todo.email}, {todo.phone}
</li>
<button onClick={delTodo} color='danger'>
Delete
</button>
</div>
))}
This is what i get when i console.log
link to image
Update your delTodo function as below.
splice uses first parameter as start index from array that you want to remove and second parameter is deleteCount. So in your case you need to get index of your object.
You can get index of object with indexOf(). It will return -1 of object does not belong to that array. So add if (index != -1) { } and then you can use todos.splice(index, 1); inside it.
const delTodo = (e, id) => {
e.preventDefault();
console.log(id);
let index = todos.indexOf(id);
if (index != -1) {
todos.splice(index, 1);
}
setTodos([...todos]);
}
Related
what my issue is
Scenario 1: It is not opening sub-lists after searching or removing any list name from the search bar
Scenario 2: After searching any list name in the search bar that is already selected, then after searching that selected list it is showing that list but its checkbox is not selected.
so what do I need after searching list name in the search bar if that list has a sub-list for example if I New Watchlists then I want to show that sub-list also that present under this list after searching in the search bar but right it coming with empty list you can see image below..
const hasSearchTerm = (n, searchTerm) =>
n.toLowerCase().indexOf(searchTerm.toLowerCase()) !== -1;
const filterData = (arr, searchTerm) =>
arr?.filter(
(n) =>
hasSearchTerm(n.title, searchTerm) ||
filterData(n.children, searchTerm)?.length > 0
);
function filteredTreeData(data, searchString, checkedKeys, setExpandedTree) {
let keysToExpand = [];
const filteredData = searchString
? filterData(data, searchString).map((n) => {
keysToExpand.push(n.key);
return {
...n,
children: filterData(n.children, searchString, checkedKeys)
};
})
: data;
setExpandedTree([...keysToExpand]);
return filteredData;
}
const Demo = () => {
const [expandedKeys, setExpandedKeys] = useState([]);
const [checkedKeys, setCheckedKeys] = useState([]);
const [selectedKeys, setSelectedKeys] = useState([]);
const [autoExpandParent, setAutoExpandParent] = useState(true);
const [searchValue, setSearchValue] = useState("");
const [tree, setTree] = useState(treeData);
const onExpand = (expandedKeysValue) => {
console.log("onExpand", expandedKeysValue); // if not set autoExpandParent to false, if children expanded, parent can not collapse.
// or, you can remove all expanded children keys.
setExpandedKeys(expandedKeysValue);
setAutoExpandParent(false);
};
const onCheck = React.useCallback(
(checkedKeysValue, e) => {
if (e.checked) {
if (e.node?.children?.length) {
setCheckedKeys(
_.union(
checkedKeys,
_.cloneDeep([
...e.node.key,
...e.node.children.map((child) => child.key)
])
)
);
} else {
setCheckedKeys(_.union(checkedKeys, [e.node.key]));
}
} else {
if (e.node?.children?.length) {
setCheckedKeys(
_.union(
checkedKeys.filter((item) => {
return (
item !== e.node.key &&
!e.node.children.filter((child) => child.key === item).length
);
})
)
);
} else {
setCheckedKeys(
_.cloneDeep(checkedKeys.filter((item) => item !== e.node.key))
);
}
}
},
[checkedKeys, setCheckedKeys]
);
const onSelect = (selectedKeysValue, info) => {
console.log("onSelect", info);
setSelectedKeys(selectedKeysValue);
};
React.useEffect(() => {
const checked = [];
treeData.forEach((data) => {
data.children.forEach((item) => {
if (item.checked) {
checked.push(item.key);
}
});
});
setCheckedKeys(checked);
}, []);
function sleep(ms) {
return new Promise((resolve) => setTimeout(resolve, ms));
}
React.useEffect(() => {
if (searchValue) {
const filteredData = filteredTreeData(
treeData,
searchValue,
checkedKeys,
setExpandedKeys
);
setTree([...filteredData]);
} else {
setTree(treeData);
// setExpandedKeys([]);
}
}, [searchValue, checkedKeys]);
return (
<div>
<Search
style={{ marginBottom: 8 }}
placeholder="Search"
onChange={(e) => {
setSearchValue(e.target.value);
}}
/>
<Tree
checkable
onExpand={onExpand}
expandedKeys={expandedKeys}
autoExpandParent={autoExpandParent}
onCheck={onCheck}
checkedKeys={checkedKeys}
onSelect={onSelect}
selectedKeys={selectedKeys}
treeData={tree}
/>
</div>
);
};
CodeSandBox Link
When you run the filterTreeData function, you assign the children to only the tree that contains the search term. So, you're searching n levels deep for the term. Notice that it works like I'd expect it to if you only search one level deep. That is, if the node has children, you return the node as such rather than filtering down all the children that don't also contain the term. when you filter with the string "new" in your example, you'll notice that none of the children in the collection "New Watchlists" contain the term and they are therefore filtered out leaving you with an empty array. My naive solution is to just return the children as in my following example:
function filteredTreeData(data, searchString, checkedKeys, setExpandedTree) {
let keysToExpand = [];
const filteredData = searchString
? filterData(data, searchString).map((n) => {
keysToExpand.push(n.key);
return {
...n,
children: n.children
};
})
: data;
setExpandedTree([...keysToExpand]);
return filteredData;
}
I call this solution naive, because I'm not exactly sure what your use case is. There might be more conditional logic you need to render in there for first searching n levels deep for the term and then and returning the whole node if the term is discovered anywhere inside the node or children.
On my current application, if a user tries to enter an existing name that has a different number, it will prompt the user if they want to update that entry with the new number. If yes, the entry is updated using an axios PUT request. My issue is that I can only get it to change on the front end by reloading the page (it updates successfully on db.json) instead of it updating immediately after the user confirms. On my useEffect method I tried adding [persons] as the second argument and it seemed to work, but found out that it loops the GET requests infinitely. I have a similar function for when deleting an entry so I'm sure it must be something that has to be added to setPersons
Update methods
const addEntry = (event) => {
event.preventDefault();
const newPersonEntry = {
name: newName,
number: newNumber,
}
const all_names = persons.map(person => person.name.toUpperCase())
const all_numbers = persons.map(person => person.number)
const updatedPerson = persons.find(p => p.name.toUpperCase() === newName.toUpperCase())
const newPerson = { ...updatedPerson, number: newNumber };
if (newName === '') {
alert('Name entry cannot be blank')
return
}
if (newNumber === '') {
alert('Number entry cannot be blank')
return
}
if (all_numbers.includes(newNumber)) {
alert('That number already exists')
return
}
if (newNumber.length < 14) {
alert('Enter a valid number')
return
}
if (all_names.includes(newName.toUpperCase())) {
if (window.confirm(`${newName} already exists, replace number with the new one?`)) {
console.log(`${newName}'s number updated`)
personService
.update(updatedPerson.id, newPerson)
.then(res => {
setPersons() //something here
})
return
}
return
}
personService
.create(newPersonEntry)
.then(person => {
setPersons(persons.concat(person))
setNewName('')
setNewNumber('')
})
}
//PUT exported as personService
const update = (id, newObject) => {
const request = axios.put(`${baseURL}/${id}`,newObject)
return request.then(response => response.data)
}
Other code
const App = () => {
const [persons, setPersons] = useState([])
useEffect(() => {
personService
.getAll()
.then(initialPersons => {
setPersons(initialPersons)
})
}, [])
...
//Display method
const filteredNames = persons.filter(person => person.name.toLowerCase().includes(filter.toLowerCase()))
const row_names = () => {
return (
filteredNames.map(person =>
<p key={person.id}>{person.name} {person.number} <button onClick={() => handleDelete(person)}>delete</button></p>));
}
...
//Render
return (
<div>
<h2>Phonebook</h2>
<h2>Search</h2>
<SearchFilter value={filter} onChange={handleFilterChange} />
<h2>Add Entry</h2>
<Form onSubmit={addEntry}
name={{ value: newName, onChange: handleNameChange }}
number={{ value: newNumber, onChange: handleNumberChange }}
/>
<h2>Numbers</h2>
<DisplayPersons persons={row_names()} />
</div>
)
}
The solution here is a little bit tricky but doable . You need to split your logic into two parts like this :
const [dataChanged , setDataChanged] = useState(false)
useEffect(()=>{
// Rest of your logic here
} , [dataChanged])
useEffect(()=>{
// Your logic will run only one time
// on Success we change the dataChanged state so the other useEffect will
// run basically you can run the rest of your logic in the other
// useEffect so the infinite loop won't happen
// setDataChanged( (prev) => !prev )
} , [])
Was able to use map method that worked
personService
.update(updatedPerson.id, newPerson)
.then(res => {
setPersons(persons.map(p => p.id !== updatedPerson.id ? p : res))
})
I have a set of card objects that I map over.
When I click on a card it adds the selected class which in turn gives it a border to show the user it is selected, it also adds the id of the card to the selectedCards useState array.
WHAT I WANT TO HAPPEN:
Each card object has a creditAvailable key state which is equal to a figure.
On selection (click) of the card, in addition to selecting the card I would also like to add up the creditAvailable and display it on the screen. and when I unselect the card I would like the figure to go down.
WHAT I HAVE TRIED:
I thought it would be as simple as calling the function to add up the credit inside the first function which selects the card, however when console logging inside the first function I see that the state has not yet updated. (scope).
I then tried to call the function outside of the first function but it gave me an infinite loop. Here is my code.
Any ideas? Thanks
const [cards, setCards] = useState([]);
const [selectedCards, setSelectedCards] = useState([]);
const [total, setTotal] = useState();
const handleSelectCard = (id) => {
if (selectedCards.includes(id)) {
const filteredIds = selectedCards.filter((c) => c !== id);
setSelectedCards([...filteredIds]);
} else {
setSelectedCards([...selectedCards, id]);
}
// addUpCreditAvailable(); // nothing happens
console.log(selectedCards); // []
};
console.log(selectedCards) // [1] for example. This is in the global scope
const addUpCreditAvailable = () => {
console.log("inside add up credit");
const chosenCards = selectedCards.map((id) => {
const foundCard = allCards.find((card) => {
return card.id === id;
});
return foundCard;
});
const result = chosenCards.reduce((acc, card) => {
return acc + card.creditAvailable;
}, 0);
setTotal(result);
return result;
};
return (
<div className="Container">
<UserInputForm submitData={handleSubmitData} />
<h1> Cards available to you displayed are below!</h1>
{cards.map(
({
id,
name,
number,
apr,
balanceTransfer,
purchaseDuration,
creditAvailable,
expiry,
}) => (
<CreditCard
key={id}
name={name}
number={number}
apr={apr}
balanceTransferDuration={balanceTransfer}
purchaseOfferDuration={purchaseDuration}
creditAvailable={creditAvailable}
expiry={expiry}
onClickCard={() => handleSelectCard(id)}
selected={selectedCards.includes(id)}
/>
)
)}
<span> £{total}</span>
)}
I figured it out with the help from above. As Wilms said i had to return the result of the handleSelectCard function and return the result of the addUpCredit function. Then I called the addUpCreditAvailable with the selectedCards state and stored the result in a variable which i then displayed in my render method.
const [cards, setCards] = useState([]);
const [selectedCards, setSelectedCards] = useState([]);
const handleSelectCard = (id) => {
if (selectedCards.includes(id)) {
const filteredIds = selectedCards.filter((c) => c !== id);
setSelectedCards([...filteredIds]);
} else {
setSelectedCards([...selectedCards, id]);
}
return selectedCards;
};
const addUpCreditAvailable = (selectedCards) => {
const chosenCards = selectedCards.map((id) => {
const foundCard = allCards.find((card) => {
return card.id === id;
});
return foundCard;
});
const result = chosenCards.reduce((acc, card) => {
return acc + card.creditAvailable;
}, 0);
return result;
};
const totalCredit = addUpCreditAvailable(selectedCards);
render method:
render (
[...]
{selectedCards.length && (
<div className={bem(baseClass, "total-credit")}>
Total Credit available: £{totalCredit}
</div>
)}
[...]
)
I want to select an item from a list and to highlight it. I got a function on how to delete a particular item from the array, i want to reuse this function to highlight it.
Data is an array of objects. I want to use hooks to manage state. id is asigned to every item in the array. I want to presshandler function as property for onPress.
const [selected, setSelect] = useState(Data);
const presshandler = (id) => {
setSelect((prev) => {
return prev.filter((list) => list.id !== id);
});
};
If I get it right, you want to set highlighted to true after you press an image:
const toggleSelect = id => {
setSelect(prev => {
return prev.map(item => {
if(item.id !== id) return item
return {
...item,
highlighted: !item.highlighted
}
})
})
}
// Usage:
<Image onPress={() => toggleSelect(image.id)} {...rest} />
After reading your comment, I see you want a toggle. So I edited my example.
I have an array of objects in todos state hook. And I want to change a single property if it is completed. Seems I can update it but without using setTodos. I am a React beginner.
const [todos, setTodos] = useState([]);
const [input, setInput] = useState("");
const addTodoHandler = (e) => {
e.preventDefault();
if (input.length < 2) return;
setTodos([...todos, { id: Date.now(), text: input, isComplete: false }]);
setInput("");
};
const removeHandler = (id) => {
setTodos(todos.filter((todo) => todo.id !== id));
};
const completeHandler = (id) => {
// working without setTodo()
// errors when added setTodo()
todos.map((todo) =>
todo.id === id ? console.log((todo.isComplete = !todo.isComplete)) : ""
);
};
<div className="todolist">
{todos.map((todo) => (
<Todo
key={todo.id}
id={todo.id}
text={todo.text}
removeHandler={removeHandler}
completeHandler={completeHandler}
isComplete={todo.isComplete}
/>
))}
</div>
To fix this inside completeHandler() first create a new array using map() method and inside map() method update the isComplete for the current todo and simply return the updated value like:
var updatedTodos = todos.map((todo) => todo.id === id ? {
...todo,
isComplete: !todo.isComplete
} : todo);
Then inside setTodos() just return this new updatedTodos array like:
setTodos(updatedTodos);
You can also do this in one-line like:
setTodos(todos.map((todo) => todo.id === id ? { ...todo, isComplete: !todo.isComplete } : todo));
But the previous code provides more readability and also helps in better debugging if you want to check each variable line by line.