Retrieve the latest data by using API link - reactjs

Goal:
Every time when I press the Button 'Test' you always need to fetch fresh data from backend by using API link. Then it should be displayed on the modalform.
Problem:
When I change the text in the input box or delete all text and then closing the modal and then click on the button Test again. The latest changes of what I have done would display. It shouldn't be happening because you always should get the latest data from backend by using API link.
Question:
How should the code always retrieve the data by using api link when you always press on the button 'test'?
Stackblitz:
https://stackblitz.com/edit/react-ts-byxk6x?file=index.tsx
Thank you!
index.tsx
import React, { FC, useState } from 'react';
import { render } from 'react-dom';
import './style.css';
import { TestModalForm } from './TestModalForm';
interface AppProps {}
interface AppState {
name: string;
}
const App: FC<AppProps> = () => {
return (
<div>
<button data-bs-toggle="modal" data-bs-target="#myModal">
Test
</button>
<br />
<TestModalForm />
</div>
);
};
render(<App />, document.getElementById('root'));
TestModalForm.tsx
import React, { useState } from 'react';
export const TestModalForm = () => {
const [inputid, setInputid] = useState('');
const [inputTitle, setInputTitle] = useState('');
React.useEffect(() => {
async function FetchData() {
var data = await fetch(
'https://jsonplaceholder.typicode.com/todos/1'
).then((res) => {
return res.json();
});
setInputid(data.id);
setInputTitle(data.title);
}
FetchData();
}, []);
const handleIdInput = (e: any) => {
setInputid(e.target.value);
};
const handleTitleInput = (e: any) => {
setInputTitle(e.target.value);
};
// Reset Input Field handler
const resetInputField = () => {
setInputid('');
setInputTitle('');
};
return (
<div>
<div
className="modal"
id="myModal"
data-bs-backdrop="static"
data-bs-keyboard="false"
tabIndex={-1}
aria-labelledby="staticBackdropLabel"
aria-hidden="true"
>
<div className="modal-dialog">
<div className="modal-content">
<div className="modal-header">
<h4 className="modal-title">TEST</h4>
<button
type="button"
className="btn-close btn-close-white"
data-bs-dismiss="modal"
></button>
</div>
<div className="modal-body">
<input
type="text"
className="form-control"
placeholder="Id"
value={inputid}
onChange={handleIdInput}
/>
<br />
<input
type="text"
className="form-control"
placeholder="Title"
value={inputTitle}
onChange={handleTitleInput}
/>
<br />
<button className="form-control" onClick={resetInputField}>
Reset
</button>
</div>
</div>
</div>
</div>
</div>
);
};

A simple solution would be to introduce some state to the App component, updated by the test button being clicked, that could be passed to the TestMOdalForm to be used as an useEffect dependency.
It's also anti-pattern to mix async/await with Promise-chains. Pick one or the other.
Example:
const App: FC<AppProps> = () => {
const [id, setId] = useState(0);
return (
<div>
<button
data-bs-toggle="modal"
data-bs-target="#myModal"
onClick={() => setId((c) => c + 1)} // <-- update state upon click
>
Test
</button>
<br />
<TestModalForm id={id} /> // <-- pass state as prop
</div>
);
};
...
const TestModalForm = ({ id }) => { // <-- destructure prop
...
React.useEffect(() => {
async function fetchData() {
try {
const response = await fetch(
'https://jsonplaceholder.typicode.com/todos/1'
);
const data = await response.json();
setInputid(data.id);
setInputTitle(data.title);
} catch(error) {
// handle any fetch rejections or other thrown errors
}
}
fetchData();
}, [id]); // <-- pass prop as dependency
...
return (
...
);
};

Related

How to handle multiple select options submittion in react js?

I want to submit a form into mongoDB using nodejs API & reactJs. With the exception of the multiple select option, everything is operating as it should be.
Being new to react, I have no idea how to handle the multi select option's onChange method.
Here is what I've tried:
import React, { useState, useRef } from "react";
import { useForm } from "react-hook-form";
import { v4 as uuidv4 } from 'uuid';
import axios from "axios";
import Select from 'react-select';
export default function EventForm(props) {
const {
register,
handleSubmit,
reset,
formState: { errors },
} = useForm();
const form = useRef();
const [loading, setLoading] = useState(false);
const [info, setInfo] = useState("");
const [analysis, setAnalysis] = useState("Undefined");
const [relatedEvent, setRelatedEvent] = useState([]);
const handleInfoChange = (e) => {
setInfo(e.target.value)
}
const handleAnalysisChange = (e) => {
setAnalysis(e.target.value)
}
const handleRelatedEvents = (e) => {
setRelatedEvent(e.target.value)
}
const relatedEventsData = props.data.map(opt => ({ label: opt.info, value: opt._id }));
const onSubmit = async () => {
setLoading(true);
const MySwal = withReactContent(Swal);
const eventData = {
UUID: uuidv4(),
info: info,
analysis: analysis,
relatedEvent: relatedEvent,
}
axios
.post(`${process.env.REACT_APP_PROXY}/api/events`, eventData)
.then((res) => {
console.log(res);
setLoading(false);
MySwal.fire(
"Success!",
"A new event has been saved successfully",
"success"
);
})
.catch((error) => {
console.log(error);
});
};
return (
<div className="panel-body">
<Form
ref={form}
onSubmit={handleSubmit(onSubmit)}
className="form-horizontal"
>
<div className="row">
<div className="col-lg-6">
<div className="mb-3">
<Form.Label>Info</Form.Label>
<Form.Control
type="text"
placeholder="Enter info..."
{...register("info", { required: true })}
value={info}
onChange={handleInfoChange}
/>
{errors.info && (
<ul className="parsley-errors-list filled" id="parsley-id-7" aria-hidden="false">
<li className="parsley-required">This value is required.</li>
</ul>
)}
</div>
</div>
<div className="col-lg-6">
<div className="mb-3">
<Form.Label>Related events</Form.Label>
<Select
options={relatedEventsData}
value={relatedEvent}
isMulti
onChange={handleRelatedEvents}
/>
</div>
</div>
<div className="col-lg-12">
<Button variant="primary" type="submit">
{loading ? "Saving..." : "Save"}
</Button>
</div>
</div>
</Form>
</div>
);
}
Could you please guide me how to make it work!
Thank you
you can make use of Select onChange event handler which passes the selected options as an array as argument ..
from that you can map over it to get the values as required
something as below:
const handleChange = (opts) => {
const selectedValues = opts.map((opt) => opt.value);
setSelectedValues(selectedValues);
};
Please check the working sample for better clarity 😉 -

How to render form after submission in react?

Given the following form, I need whenever the form is submitted, the new post to be listed/rendered without having to refresh the page.
const PostCreate = () => {
const [title, setTitle] = useState('');
const onSubmit = async (event) => {
event.preventDefault();
await axios.post(`http://${posts_host}/posts/create`, {title}).catch(error => {
console.log(error)
})
setTitle('');
};
return (<div>
<form onSubmit={onSubmit}>
<div className="form-group">
<label>Title</label>
<input value={title} onChange={event => setTitle(event.target.value)}
className="form-control "/>
</div>
<button className="btn btn-primary">Submit</button>
</form>
</div>)
}
export default PostCreate;
I tried adding this.forceUpdate() and this.setState(this.state), neither works, and I still have to refresh the page for the new post to show.
Here's how the posts are rendered:
const PostList = () => {
const [posts, setPosts] = useState({});
const fetchPosts = async () => {
await axios.get(`http://${queries_host}/posts`).then(response => {
setPosts(response.data);
}).catch(error => {
console.log(error)
});
};
useEffect(() => {
fetchPosts();
}, []);
const renderedPosts = Object.values(posts).map(post => {
return <div className="card"
style={{width: '30%', marginBottom: '20px'}}
key={post.id}>
<div className="card-body">
<h3>{post.title}</h3>
<CommentList comments={post.comments}></CommentList>
<CommentCreate postId={post.id}></CommentCreate>
</div>
</div>
});
return <div>
{renderedPosts}
</div>;
}
export default PostList;
This is what App.js looks like
const App = () => {
return <div>
<h1>Create Post</h1>
<PostCreate></PostCreate>
<hr/>
<h1>Posts</h1>
<PostList></PostList>
</div>;
};
export default App;
and is eventually rendered using:
ReactDOM.render(
<App></App>,
document.getElementById('root')
)
In your PostList, useEffect called once when you first load your component, so when you create new post, it will not be re-rendered
You should bring your fetchPost logic to your App component, and add function props onPostCreated to PostCreate component, trigger it after you finish creating your new post
The code should be:
const App = () => {
const [posts, setPosts] = useState({});
const fetchPosts = async () => {
await axios.get(`http://${queries_host}/posts`).then(response => {
setPosts(response.data);
}).catch(error => {
console.log(error)
});
};
useEffect(() => {
fetchPosts();
}, []);
return <div>
<h1>Create Post</h1>
<PostCreate onCreatePost={() => fetchPost()}></PostCreate>
<hr/>
<h1>Posts</h1>
<PostList posts={posts}></PostList>
</div>;
};
export default App;
const PostList = ({ posts }) => {
const renderedPosts = Object.values(posts).map(post => {
return <div className="card"
style={{width: '30%', marginBottom: '20px'}}
key={post.id}>
<div className="card-body">
<h3>{post.title}</h3>
<CommentList comments={post.comments}></CommentList>
<CommentCreate postId={post.id}></CommentCreate>
</div>
</div>
});
return <div>
{renderedPosts}
</div>;
}
export default PostList;
const PostCreate = ({ onCreatePost }) => {
const [title, setTitle] = useState('');
const onSubmit = async (event) => {
event.preventDefault();
await axios.post(`http://${posts_host}/posts/create`, {title}).catch(error => {
console.log(error)
})
onCreatePost && onCreatePost();
setTitle('');
};
return (<div>
<form onSubmit={onSubmit}>
<div className="form-group">
<label>Title</label>
<input value={title} onChange={event => setTitle(event.target.value)}
className="form-control "/>
</div>
<button className="btn btn-primary">Submit</button>
</form>
</div>)
}
export default PostCreate;
I think the problem you are having is not in the code you have displayed. The component is indeed rerendering after you change its state and also when you forceUpdate() it. I assume the posts you are trying to display are taken from the same API that you post to. Even if this component is being rerendered, your GET request which gives the data to the component who renders it is not called again so the data doesn't update. You need to refetch it. This can be done by many different ways (useEffect(), callbacks, reactQuery refetch) depending on the rest of your code. I would need the component that renders the data and the API call to help you further.
Another thing that you didn't ask but is good practice. In your PostCreate component you don't need to manage the state of fields that are in the form, because it already does it for you. Just give a name to your inputs and use the form data. I've given an example below.
import { useState } from "react";
const PostCreate = () => {
const onSubmit = async (event) => {
event.preventDefault();
console.log(event.target.elements.title.value);
};
return (
<div>
<form onSubmit={onSubmit}>
<div className="form-group">
<label>Title</label>
<input name="title" className="form-control" />
</div>
<button className="btn btn-primary">Submit</button>
</form>
</div>
);
};
export default PostCreate;

react js myfn is not a function when called from a button

I've just started learning about react js and this is my first react js app. I'm using api to fetch the data. so far it works, but now I want to add a search keyword to the function that is acquired from a search bar component.
here's my code:
SearchBar.js
const SearchBar = ({ getUsers }) => {
return (
<div className="is-flex flex-align-items-center mb-3">
<input type="text" id="query" className="input search-input" placeholder="search keyword"/>
<Button className="search-btn ps-3 pe-3"
onClick={() => getUsers(document.querySelector('#query').value)}>
<FontAwesomeIcon icon={faMagnifyingGlass} />
</Button>
</div>
);
};
MasterUser.js
import { useState, useEffect } from "react";
import SearchBar from "./SearchBar";
const MasterUser = () => {
const [users, setUsers] = useState([]);
useEffect(() => {
getUsers();
}, []);
const getUsers = async (query='') => {
console.log('get users', query);
try {
let myurl = 'http://localhost:8080/users';
const response = await fetch(myurl);
const data = await response.json();
setUsers(data);
setIsLoading(false);
} catch (e) {
console.log(e.getMessage());
}
};
return (
<div>
<SearchBar onClick={getUsers}/>
</div>
);
};
when the app loads, the console log says get users <empty string> and it returns all the users as expected, but when I clicked on the search button (magnifyingGlass) it gives an error Uncaught TypeError: getUsers is not a function.
any help is appreciated..
<SearchBar onClick={getUsers}/>
You have named the prop onClick not getUsers. That's why you get that error.
Yeah, accessing dom element value using selectors (e.g. document.querySelector('#query').value) is also not typical react. Read about controlled form elements (save form element value in state).
Make your searchBar component more reactive like so
const SearchBar = ({ getUsers }) => {
const [searchValue,setSearchValue]=useState('');
return (
<div className="is-flex flex-align-items-center mb-3">
<input type="text" id="query" className="input search-input" placeholder="search keyword" value={searchValue} onChange={(e)=>setSearchValue(e.target.value)}/>
<Button className="search-btn ps-3 pe-3"
onClick={() => getUsers(searchValue)}>
<FontAwesomeIcon icon={faMagnifyingGlass} />
</Button>
</div>
);
};

Rerender sibling component in React

I am new to React. I am stuck on this problem for days now.
I have got a parent component which wraps two sibling components, "FileUpload" and "Documents"
The "FileUpload" is for uploading a file and "Documents" is for displaying all the uploaded files.
I want the "Documents" rerender after a new file is uploaded via "FileUpload", so that it shows the new file in the UI.
What would be the best approach to achieve this ?
Below is the code I have written so far for the sibling components:
FileUpload:
import React, { useState } from "react";
import Axios from "axios";
const FileUpload = (props) => {
const [files, setFiles] = useState([]);
const onInputChange = (e) => {
setFiles(e.target.files);
};
const handleSubmit = async (e) => {
e.preventDefault();
const data = new FormData();
for (let i = 0; i < files.length; i++) {
// console.log(files);
data.append("file", files[i]);
}
data.append("parentDbId", props.parentDbId);
data.append("parentObject", props.parentObject);
//console.log(data);
try {
await Axios.post("http://localhost:5000/upload", data);
} catch (err) {
console.error(err.message);
}
};
return (
<form
// action="http://localhost:5000/upload"
// method="POST"
//encType="multipart/form-data"
onSubmit={handleSubmit}
>
<div className="row mb-3">
<div className="col-lg-4">
<label htmlFor="formFileMultiple" className="form-label mb-0">
Add files
</label>
<input
className="form-control"
type="file"
id="formFileMultiple"
name="file"
multiple
onChange={onInputChange}
/>
</div>
<div className="col-lg-4 mt-0 gx-0">
<button type="submit" className="btn btn-primary mt-4">
Upload
</button>
</div>
</div>
</form>
);
};
export default FileUpload;
====================================================================
Documents:
import React, { useState, useEffect } from "react";
import axios from "axios";
const Documents = (props) => {
const parentDbId = props.parentDbId;
const [documents, setDocuments] = useState([]);
//mount
useEffect(() => {
console.log("first use effect");
loadDocuments();
}, []);
const loadDocuments = async () => {
const result = await axios.get(
`http://localhost:5000/documents/${parentDbId}`
);
setDocuments(result.data);
};
return (
<>
<div className="row">
{documents.map((document, index) => (
<div className="col-lg-3" key={index}>
<a href={document.filePath}>{document.fileName}</a>
</div>
))}
</div>
</>
);
};
export default Documents;
Thanks,
Jimmy
Simple, just have the parent control document state and pass the state and callback down to the children as a prop. Now the siblings are referencing the same state and will be re-rendered when props (ie document state) changes. The parent can also handle the data fetching and uploading.
it will look like this:
const Parent = () => {
const [documents, setDocuments] = useState([]);
...do data fetching here
const handleSubmit = useCallback(async () => {}, []); // You might want to reset document state here?
return (
<div>
<Docs documents={documents} />
<Upload onUpload={setDocuments} onSubmit={handleSubmit} />
</div>
);
}
I wonder if you should actually have two documents components, one for displaying the files being uploaded, and one for displaying the already uploaded files. You would embed one within the Upload component and the other would fetch documents from the api every time onUpload completes

Why it is rendering first and then updating the state later in react?

I want to fetch the data when the button is clicked but the Newsitem component is running first and then updating the value of data_grabber. That means it is displaying the defalut values rather than the data that I fetched from the newsapi. After displaying the newsitem component with default values, data_grabber is updating the fetched data.
What can be the solution?
App.js
function App() {
const [input_data, setInput_data] = useState("");
const [btn_data, setBtn_data] = useState("");
const [data_grabber, setData_grabber] = useState([]);
return (
<>
<Navbar
input_data={input_data}
setInput_data={setInput_data}
setBtn_data={setBtn_data}
btn_data={btn_data}
data_grabber={data_grabber}
setData_grabber={setData_grabber}
/>
{data_grabber? data_grabber.map((news_data)=>{
return(
<NewsItem news_data={news_data}/>
)
}):<div>No data available</div>}
</>
);
}
export default App;
Navbar.js
import { useEffect } from "react";
export default function Navbar(props) {
const onClicker = async (e) => {
e.preventDefault();
props.setBtn_data(props.input_data);
};
useEffect(() => {
const fetcher = async () => {
const link = `https://newsapi.org/v2/everything?q=${props.btn_data}&apiKey=API_KEY`;
const raw_data = await fetch(link);
const data = await raw_data.json();
console.log(data);
props.setData_grabber(data.articles)
};
fetcher();
}, [props.btn_data]);
return (
<div>
<form className="d-flex">
<input
onChange={(e) => props.setInput_data(e.target.value)}
value={props.input_data}
className="form-control me-2"
type="search"
placeholder="Search"
aria-label="Search"
/>
<button
className="btn btn-outline-success"
type="submit"
onClick={onClicker}
>
Search
</button>
</form>
</div>
NewsItem.js
import React, { Component } from "react";
export default class NewsItem extends Component {
render() {
const {title, description, url, urlToImage} = this.props.data
const defaultImage = `https://blogger.googleusercontent.com/img/a/AVvXsEh20SgNNsDlKyWWmB7XgB5SfFY10M6CqJAq93HwGtssTn2cWz6w9zHPjXf91WwoWr27QeaC4HsGv2NxPOXUdvk6xodUojnw8rUuAkEMY3Qb4ucoVpN3nSyF8JW_xVDWa2aSMEWH387hPsfouSJyClLNburIcDbXIeJamuTHwiSvw4hdNnqeeICcvg1wrQ=w1200-h630-p-k-no-nu`
return (
<div>
<div className="card">
<img src={urlToImage?urlToImage:defaultImage} className="card-img-top" alt="..." />
<div className="card-body">
<h5 className="card-title">{title?title:'No title available'}</h5>
<p className="card-text">
{description?description.slice(0, 50):"no description available"}...
</p>
<a href={url} target="_blank" rel="noreferrer"className="btn btn-primary">
read more
</a>
</div>
</div>
</div>
);
}
}
One fix could be to
make a variable of the updated state:
in the UseEffect ,
add :
const updated = data.articles
props.setData_grabber(updated)
Check whether data_grabber array is empty or not and then do the rendering inside App component as follows.
{
data_grabber.length > 0 ? (
data_grabber.map((news_data) => {
return <NewsItem news_data={news_data} />;
})
) : (
<div>No data available</div>
);
}
{ data_grabber !== undefined && data_grabber.length > 0 ? data_grabber.map((news_data)=>{
return(
<NewsItem news_data={news_data}/>
)
}):<div>No data available</div>}
Check data_grabber is undefined or empty.
Then, fix NewsItem props.data like this.
export default class NewsItem extends Component {
render() {
const {title, description, url, urlToImage} = this.props.news_data
also fix here in useEffect
useEffect(() => {
const fetcher = async () => {
const link = `https://newsapi.org/v2/everything?q=${props.btn_data}&apiKey=c990aa0235da4635997afd1f7459860c`;
const raw_data = await fetch(link);
const data = await raw_data.json();
console.log(data);
if(data.articles){
props.setData_grabber(data.articles)
}
};
fetcher();

Resources