I've been searching to solve this problem for a while but couldn't find a working solution.
I'm making a simple social network website and this API returns a article data such as text, image and video url, etc, all saved in server's local MySQL Database. My front-end is React and server is Nginx reverse proxy with Node.js using Express. When I load the page, I create 5 React components that each make fetch request for given article number.
The following code snippet is the fetch API that asks the server to fetch data from database:
//server-side script
app.get('/api/getArticle/:id', (req, res) => {
const con = mysql.createConnection({
host: 'myhost_name',
user: 'myUser',
password: 'myPassword',
database: 'myDB',
});
con.connect(function (err) {
if (err) {
throw err;
}
console.log("Connected!");
})
const idInterest = req.params.id.toString();
console.log(idInterest)
let sql = 'some_sql';
con.query(sql, function (err, result) {
if (err) {
res.status(500).send("Error while getting article data");
return;
}
else {
res.set('Connection', 'close')
res.status(200).send(result);
console.log("ended")
con.end();
return;
}
})
}
//React script
//index.js
fetch('http://mywebsite.com/api/getMaxArticleId/')//Retrieve top 5 article ID
.then((response) => {
for (let i = 0; i < data.length; i++) {
nodesList.push(<Container articleId={data[i]['id']}/>)
}
ReactDOM.render(<React.StrictMode><NavBar />{nodesList}<Writer writer="tempWriter" /></React.StrictMode>, document.getElementById('root'));
})
//Container.jsx; componentDidMount
const url = "http://mywebsite.com/api/getArticle/" + this.props.articleId.toString();
fetch(url, {
method: 'GET',
credentials: "include",
}).then((response) => {
response.json().then((json) => {
console.log(json);
//processing json data
This used to work very fine, but suddenly the getArticle/:id calls started to show 200 status but 'pending' in 'time' column in Chrome network tab, endlessly, all except the first*getArticle/:idcall. This prevents my subsequent .then() in each Container from being called and thus my entire tab is frozen.
Link to image of network tab
As you see from the image, all pending fetches are missing 'Content Download' and stuck in 'Waiting(TTFB)', except the first call, which was '39'
I checked the API is working fine, both on Postman and Chrome, the server sends result from DB query as expected, and first call's Json response is intact. I also see that console.log(response.json()) in React front-end shows Promise{<pending>} with *[[PromiseStatus]]: "Resolved"* and *[[PromiseValue]]* of Array(1) which has expected json data inside.
See Image
This became problematic after I added YouTube upload functionality with Google Cloud Platform API into my server-side script, so that looks little suspicious, but I have no certain clue. I'm also guessing maybe this could be problem of my React code, probably index.js, but I have no idea which specific part got me so wrong.
I've been working on this for a few days, and maybe I need common intelligence to solve this (or I made a silly mistake XD). So, any advices are welcomed :)
Related
My ReactJS project displays a simple page consisting of a header section with project title, version and a few nav links, then a table of about 200 results as the main content of the page.
The initial page loads for everyone and the components appear as expected, but on page load (I believe this is when the useEffect hook kicks in) some users report the page becoming un-responsive and no matter how long it is left, it never finishes. This has been reported in both Chrome and Edge by 5 different users across a site of 200+ users, the majority have no issues despite running the exact same hardware and connection.
On page load, I expect the title, version and table contents (plus a few other variables) to be populated and automatically updated since these are in state, and for most users, this works as expected.
Below is my useEffect()
useEffect(() => {
// Update all initial values
fetchLastUpdated();
fetchVersion();
fetchUsername();
fetchUpcomingFilterOptions();
fetchLongCustomerNames();
fetchConfigs();
fetchUpcomingResults() // This will be displayed as rows
const job = document.getElementById("job")
if ( !!job ) {
job.addEventListener("keyup", function(event) {
if (event.key === "Enter") {
submitForm()
}
});
}
// Find environment for API links: testing/pre-release, testing/QA, flx
const url = window.location.href
if ( url.includes('localhost') ) {
setEnvironment("testing/pre-release")
} else if ( url.includes('testing/pre-release') ) {
setEnvironment("testing/pre-release")
} else if ( url.includes('testing/QA') ) {
setEnvironment("testing/QA")
} else if ( url.includes('flx') ) {
setEnvironment("flx")
}
}, [])
Below an example of an API call from useEffect
const fetchConfigs = () => {
axios({
method: "get",
url: "http://myURL/" + environment + "/WITracker/public/api/myConfigs",
config: { headers: {
'Access-Control-Allow-Origin': '*',
"Content-Type": "multipart/form-data"
}}
})
.then(function (response) {
setConfigs(response.data);
})
.catch(function (response) {
console.log("Failed to fetch configs!");
addNotification("Unable to fetch configs", "Retry in progress...")
})
}
When remote accessing the users with troubles loading the page, I asked that they each try the alternative browser: Chrome -> Edge or Edge -> Chrome and in each case this resolved the issue. I found this strange as I would have expected the same browser to be causing the same behaviour each time across the users.
I would like to make sure that the page reliably loads for all users regardless of their browser preference. I'm at a bit of a loss trying to find out why only some users are getting unresponsive errors so any possible solutions or suggestions of what to try are welcome!
Possible workaround?
I'm not sure that I have set up my useEffect the correct way using best practices. I'm thinking of adding a slight delay to the API calls, since the page loads the components without issue, and once the delay is up, to synchronously make each of the calls, giving the browser more of a chance to process the smaller chunks of work rather than all at once... please can somebody let me know their thoughts on this?
e.g. Something similar to the below theory?
useEffect(async () => {
// Some delay here, with loading screen
wait(1000) //custom function to wait?
// ...then, update all initial values
await fetchLastUpdated();
await fetchVersion();
await fetchUsername();
await fetchUpcomingFilterOptions();
await fetchLongCustomerNames();
await fetchConfigs();
await fetchUpcomingResults()
...
Thanks in advance
In my project I'm using React-Dropzone-Component (https://github.com/felixrieseberg/React-Dropzone-Component) based on Dropzone.js.
I'm using this component because I'm developing a SharePoint webpart and there is already an example based on this solution on Microsoft PnP GitHub repository.
Anyway, the upload is working fine, but sometimes, mainly when I keep a web page opened for a couple of minutes doing nothing, I receive an error trying to upload new files. I retry an upload and it fails returning Server responded with (0) code error. I also see on Google Chrome console an ERR_CONNECTION_RESET error. If I try to upload 5 files in second instance, I get error on first 2-3 and then the remaining files works fine. Weird.
I've already investigated my network, but there are no failures. I've also tried with 3 different networks and I've received the same error.
I've also updated the component with the latest Dropzone.js (5.7.2).
This is my code:
let componentConfig = {
iconFiletypes: this.props.fileTypes.split(','),
showFiletypeIcon: true,
postUrl: _context.pageContext.web.absoluteUrl,
autoProcessQueue: true
};
var djsConfig = {
headers: {
"X-RequestDigest": digest1
},
addRemoveLinks:false
};
let myDropzone;
let eventHandlers = {
// This one receives the dropzone object as the first parameter
// and can be used to additional work with the dropzone.js
// object
init: function(dz){
myDropzone=dz;
},
sending: async function (file, xhr) {
var fileName = file.name;
fileName = fileName.replace(/[&\/\\#,+()$~%='":*?<>{}]/g, "");
if (file.size <= 10485760) {
// small upload
await web.getFolderByServerRelativeUrl("/test/"+_listName).files.add(fileName, file, true).then(_ => console.log("Ok!"));
} else {
// large upload
await web.getFolderByServerRelativeUrl("/test/"+_listName).files.addChunked(fileName, file, data => {}, true).then(_ => console.log("Ok!"));
}
},
error:function(file,error,xhr){
file.status = myDropzone.ADDED;
myDropzone.removeFile(file);
myDropzone.enqueueFile(file);
}
};
<DropzoneComponent eventHandlers={eventHandlers} djsConfig={djsConfig} config={componentConfig}>
<div className="dz-message icon ion-upload">Drop files here to upload</div>
</DropzoneComponent>
If I can't prevent this ERR_CONNECTION_RESET error, I would like to set up an automatic retry for these files. The code I've posted above is not working fine or it returns "Uncaught Error: This file can't be queued because it has already been processed or was rejected.".
Is there a solution or a good way to set up a retry?
I am trying to send email with SendGrid in ReactJS project.
This is my componnet:
//Email.js
import React from 'react'
const sgMail = require('#sendgrid/mail');
sgMail.setApiKey(process.env.SENDGRID_API_KEY);
const msg = {
to: 'aaaaa#gmail.com',
from: 'bbbb#gmail.com',
subject: 'This is a test mail',
text: 'and easy to do anywhere, even with Node.js',
html: '<strong>and easy to do anywhere, even with Node.js</strong>',
};
sgMail.send(msg).catch(error => {alert(error.toString()); });
export const Email= () => (
<h1>Email Sending Page</h1>
)
When I am trying to run the app with "npm start" on localhost, the email is not sent and I got the error message "TypeError: Failed to fetch".
But, if I am using this code:
//Email.js
const sgMail = require('#sendgrid/mail');
sgMail.setApiKey(process.env.SENDGRID_API_KEY);
const msg = {
to: 'aaaaa#gmail.com',
from: 'bbbb#gmail.com',
subject: 'This is a test mail',
text: 'and easy to do anywhere, even with Node.js',
html: '<strong>and easy to do anywhere, even with Node.js</strong>',
};
sgMail.send(msg)
and do this command: "node Email.js" the mail is sent. It works only this way and I cannot understand why.
I tried any solution that I could find but nothing works.
(I tried even to put the api_key hardcoded in the code just for the test and I got the same result).
EDIT
After looking around a bit I found out that you can't use Sendgrid to send email directly from the browser.
Sendgrid won't let you send an email directly using Javascript in the
browser.
You will need to have a server set-up and use the server to send the
email instead (using your favourite back-end framework/language,
Node.js, php, Java, etc.).
The steps for sending a mail will be similar to this:
Write email details in the React application
Send a POST request to
your server endpoint (for example, /sendemail) with the email data
(recipient, title, content, etc.) Receive Email data in the server and
send it to Sendgrid api Here is the official Sendgrid documentation
regarding their CORS policy:
https://sendgrid.com/docs/for-developers/sending-email/cors/
Source: React unable to send email with SendGrid
EDIT 2
If you want to implement Sendgrid without actually building and deploying a server, you can use a simple Firebase function which is free to host.
I know this may look intimidating but in reality its pretty easy. Also I just put this together real quick so if anything doesn't work out for you, shoot me a comment.
Follow steps 1-3 on the getting started page for firebase functions. It is pretty straightforward and you end up with the firebase tools CLI installed.
Navigate to the functions/ folder inside your project on the command line/terminal.
Install the Sendgrid and cors libraries in the functions folder
npm i #sendgrid/mail cors
Add your Sendgrid API key to your firebase environment with the following command in your project:
firebase functions:config:set sendgrid.key="THE API KEY"
Copy this into your functions/index.js file:
const functions = require("firebase-functions");
const cors = require("cors")({ origin: true });
const sgMail = require("#sendgrid/mail");
exports.sendEmail = functions.https.onRequest((req, res) => {
sgMail.setApiKey(functions.config().sendgrid.api);
return cors(req, res, () => {
const { msg } = req.body;
sgMail.send(msg).catch(error => {
alert(error.toString());
});
res.status(200).send(msg);
});
});
Save it and run firebase deploy --only functions on the command line. Your function should now be live at https://us-central1-<project-id>.cloudfunctions.net/sendEmail
Now change your React file to:
//Email.js
import React, { useEffect } from 'react'
export const Email= () => {
useEffect(() => {
const sendEmail = async() => {
const msg = {
to: 'aaaaa#gmail.com',
from: 'bbbb#gmail.com',
subject: 'This is a test mail',
text: 'and easy to do anywhere, even with Node.js',
html: '<strong>and easy to do anywhere, even with Node.js</strong>',
};
const response = await fetch(
'https://us-central1-FIREBASE-PROJECT-ID-HERE.cloudfunctions.net/sendEmail', {
method: 'POST',
body: JSON.stringify(msg),
headers: {
'Content-Type': 'application/json'
}
});
console.log("response", response);
}
sendEmail();
}, []);
return <h1>Email Sending Page</h1>
}
And thats it! You basically have a server side function without making a server and its free!
Feel free to ignore this if you don't feel like putting in the work but if you need any help, let me know.
I'm new to React js And I using Yii2 as my backend..! When I Send a API request to yii2 ,It Returns me the 500 Error.I don't know,Where I made a mistake.
Here is my React Js Code for API call,
fetch('localhost/learning-react/api/admin/signup', {
method: 'POST',
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json'
},
body: JSON.stringify({
fname:fname,
lname:lname,
email:email,
uname:uname,
passwd:passwd
})
}).then((response) => response.json())
.then((responseJson) => {
if(responseJson['status']==='1')
{
alert(responseJson['msg']);
}
}
And This is My Yii2 Backend code,
public function actionSignup()
{
//$model = new TblUsers();
return "success";
}
Sorry For my Inability to finding mistakes in my code..!
First of all, 500 means generic server error. So you will need to post your error log as per my comment to help on that. However, I have found your code on the backend is wrong. You do not user restful controller in your code and as such it is not a REST API at all. So I advice you to read through Restful APIs in the Guide. That being said, you basically need to:
Create Restful controller by inheriting from yii\rest\Controller.
Return either Array, DataProvider or instance of yii\base\Model to have guarantee of automated serialization to JSON
so I will show you a simple example to give you an idea. Please read the guide to get in-depth insights on REST API with Yii2.
<?php
namespace app\modules\v1\controllers;
use yii\rest\Controller;
class LoginController extends Controller
{
public function actionSignup()
{
$model = new TblUsers();
//register a user
//return registred user
return [
'success' => true,
'member' => $model;
];
}
}
Let try the following, it may help.
You are making a rest post request, this means two things, first info will travel by POST request, and second dont forget its rest.
try opening the url in the browser, unless you define a rule it should open.
So go ahead open: http://localhost/learning-react/api/admin/signup you should see a "success" on the screen, or you will se the full 500 error printed.
If you were able to open the url on the browser, try the call again, and check your chrome debugger on the network tab. Look for the 500 error open it and read the error, it should be fully printed there on the response tab i.e.
when this is solved, don't forget to enable rules to allow only POST as request, and add the appropriate format for the response so you can consume it as json.
Yii::$app->response->format = Response::FORMAT_JSON;
Hope it helps debuggin.
I have strange problem with IE11 only. I have form in my app, when I fill all inputs and try save, request to server from IE11 is send properly, then I try get this data and I recive empty collection from resposne (using axios). I use polyfill to promises and push. Where could be a problem ?
In application I use React, Redux.
Sample code:
getService(id) {
return this.api.get('/' + id)
.then(resp => {
console.log(resp.data.model.collect) // arr length 0 in other browser data are exist here
let Collection = [];
resp.data.model.collect.map((item, idx) => {
Collection.push(item)
});
return Collection;
})
.catch(err => {
throw err;
})
}
the problem is that the internet explorer browser uses data cache for load form. It's necessary stop to record cache. for this you need request your api puting in header the pragma parameter
header {
pragma: 'no-cache'
}