I noticed that some fetch requests don't reach the server when I change window.location just after sending the request (location change is not inside the promise response handler).
I tested on Chrome browser
# util.js
function sendLog(payload) {
const urlApi = `http://api.example.com/public/send-message`;
return fetch(urlApi, {
method: 'POST',
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify(payload)
}).then(response => {
return response.json();
});
}
# main.js
sendLog({
project: 'FrontEnd-Card',
countryId: country
}).then(res => {
console.log(res);
});
window.location.replace(REDIRECT_URL);
I noticed this pattern:
If network is fast, the log is successfully sent to the server
If network is slow, the log doesn't reach the server.
Somehow redirection kills the outgoing request. Is this true ? Where can I find a detailed documentation about this behavior ?
Related
Here is the snippet of my fetch json file. There is always an error when I try to fetch the json file data.
const onSearchSubmit = (term) => {
console.log(term);
fetch('./JSONDATA.json', {
method: 'get',
headers: {
'Content-Type': 'application/json',
Accept: 'application/json',
},
})
.then(function (response) {
return response.json();
})
.then(function (data) {
setFruits(data);
console.log(data.term);
})
.catch((error) => {
console.log(error + "json file");
});
};
ORIGINAL SNIPPET IMAGE
The error is not related to React nor to fetch(). It says your server has responded with 404 Not Found. This means your file is not present / not reachable.
Verify with the browser (or curl) that url http://localhost:3000/JSONDATA.json exists and is reachable
Side note
'Content-Type': 'application/json' is not required, this is the request body type header, but you do not have body.
I have the following code which works when I run it as a local serverless function with netlify dev, but I need it to run cross origin from a dev server to the hosted server function. I put the function in a aws lambda function but I am getting a cross origin blocked error on my https:dev.website.com, I thought I have the correct headers in the return object so not sure why I am getting a cross origin error.
Any help would be great
const sanityClient = require("#sanity/client");
const client = sanityClient({
projectId: "random-id",
dataset: "production",
useCdn: true,
});
exports.lambdaHandler = async (event, context) => {
var body = JSON.parse(event.body);
//console.log(body.price_id)
try {
const checkPriceId = async (test) => {
const query = `*[_type == "products" && price_id == "${body.price_id}"]`;
const documents = await client.fetch(query, {}); // this could throw
return documents.map((document) => document.sold);
};
var ok = checkPriceId().then((test) => {
return new Promise(function (resolve, reject) {
//console.log(test) // this will log the return value from line 7
console.log(test);
resolve(test);
});
});
var bools = await ok;
// prettier-ignore
return {
statusCode: 200,
headers: {
'Access-Control-Allow-Origin': '*',
'Access-Control-Allow-Headers': 'Content-Type',
'Access-Control-Allow-Methods':'GET, POST, OPTION',
},
body: JSON.stringify({
sold: bools,
}),
};
} catch (err) {
return { statusCode: 500, body: err.toString() };
}
};
This is my request to the function if that helps
var fetchUrl = https://random.executue-api.aws.com/prod/sold //not exact
var fetchData = async function () {
const response = await fetch(fetchUrl, {
method: "post",
headers: {
"Content-Type": "application/json",
},
body: JSON.stringify({
price_id: final,
}),
})
.then(res => {
return res.json()
})
.catch(error => console.log(error))
return response
}
Update:
I tried adding cors the way suggested in the answer below, but it failed seen below so I tried manually adding the method response seen after.
I still get a cross domain error. And I have changed the domain so it is now https as well. Really stuck here.
I was looking into this more, and it seems like before it does the actual post it does a cors check at the options method, so I added in the same access control headers, and deployed but did not work. Don't quite get this.
Your headers look ok to me. (note: If you mix HTTP and HTTPS you are most likely to get a mixed content error in the client). If it is ONLY a CORS issue that you are seeing in the console in the web browser, then you might not have configured the API Gateway correctly in AWS.
In AWS, go to API Gateway and you should see something like the below:
Make sure that you enable CORS and then redeploy.
UPDATE:
Just looking at a previous implementation of a lambda function I setup with AWS. The headers I declared were as follows:
headers: {
"Content-Type" : "application/json",
"Access-Control-Allow-Origin" : "*",
"Allow" : "GET, OPTIONS, POST",
"Access-Control-Allow-Methods" : "GET, OPTIONS, POST",
"Access-Control-Allow-Headers" : "*",
"Access-Control-Allow-Credentials" : true
}
Your headers look OK to me though. However, when you created the method in the API Gateway, did you select Use Proxy Lambda Integration? (see screenshot).
Your client side fetch request looks ok. For reference mine was:
const url = 'your url';
const options = {
method: 'POST',
headers: { "Content-Type": "application/json" },
body: JSON.stringify(data),
};
fetch(url, options).then(res => res.json());
Unrelated to this issue, but its not advisable to mix Async/Await with .then promise chaining. But this isn't the issue you are having. Just something to note.
Check the values from your Integration Response / try setting them manually for both OPTIONS and POST (and if that works, make sure you are passing through the response correctly from the lambda).
Your POST action should only require the Access-Control-Allow-Origin header. The other two (Access-Control-Allow-Methods, Access-Control-Allow-Headers) belong in the OPTION action. See this writeup, and note the full example exchange for a preflighted request (in grey): https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS#preflighted_requests
I've built an API using C# that uses JWT tokens for authorization. On the frontend I store these tokens in local storage and get them, when creating a request. When creating GET or DELETE requests, everything works fine, and using console.log() I can see that fetch options have the Authorization header added. However when using POST or PATCH methods, the Authorization header is missing immediatly after adding it to the object. Here is my request method:
const send = async (apiOptions: ApiParams): Promise<FetchReturn> => {
const accessToken = GetAccessToken()
const options: ApiOptions = {
method: apiOptions.method,
headers: {
Authorization: `Bearer ${accessToken}`
}
}
console.log(options)
if (apiOptions.data) {
options.headers = {
'Content-Type': 'application/json'
}
options.body = JSON.stringify(apiOptions.data)
}
const result = await fetch(`${getUrl()}/${apiOptions.path}`, options).then(res => res).catch(err => err)
if (!result.ok) {
if (IsExpired()) {
const refreshResult = await fetch(`${getUrl()}/api/user/refresh`, {method: 'POST', headers:{
'Content-Type': 'application/json'
}, body: JSON.stringify(GetRefreshRequest())}).then(res => res).catch(err => err)
if (refreshResult.ok) {
Login(JSON.parse(await refreshResult.text()))
return await send(apiOptions)
} else if (refreshResult.status === 401) {
Logout()
window.location.reload()
return { code: 0, text: ""}
}
}
}
const text = await result.text()
return { code: result.status, text: text }
}
I suppose that in apiParams for POST you have property 'data' assigned, and later you have if-condition that completely replaces request headers object.
Change it to:
options.headers['Content-Type'] = 'application/json';
To keep authorization in headers
The first time check your apiOptions.data
i think , its null when you call POST/Patch request
Just put console.log("...") In the if statement , Then try for resolve your Error
If your problem not resolved, put a replay under my post
I'm trying to fetch() text/plain data from a remote service. If I place a breakpoint in the promise "then" chain, the text data from the server is available. Without the breakpoint, I get a fetch() exception.
I am using a prototype design pattern (see below). When I place a breakpoint in the "then" chain as shown below, the data from the remote service is successfully retrieved. Without the breakpoint, the catch() is executed and the error is:
TypeError: Failed to fetch
I'm totally stumped and would appreciate any help!
Note, the server (a python app) sends back html, with
self.send_header("Access-Control-Allow-Origin", "*")
Also, if I use Ajax (FWIW, it works). I'd like to get it working with fetch() however.
function Fetch(Msg) {
// Msg contains some info on how to construct the JSON message to transmit -- not relevant here.
this.help = `
The Fetch object specifies communication basics using
the fetch(...) mechanism.
`;
// some misc object vars...
}
Fetch.prototype = {
constructor: Fetch,
postData: async function (url = '', data = {}) {
const response = await fetch(url, {
method: 'POST,
mode: 'cors',
cache: 'no-cache',
credentials: 'same-origin',
headers: {
'Content-Type': 'text/plain',
},
redirect: 'follow',
referrerPolicy: 'no-referrer',
// body data type must match "Content-Type" header
body: JSON.stringify(data)
});
return await response.text(); //
},
handleErrorsInResponse: function (response) {
var debug = new Debug("Fetch.handleErrorsInResponse");
debug.entering();
debug.leaving();
},
handleReponse: function (response) {
var debug = new Debug("Fetch.handleResponse");
debug.entering();
console.log(response);
debug.leaving();
},
handleErrorsInFetch: function (response) {
var debug = new Debug("Fetch.handleErrorsInFetch");
debug.entering();
console.log(response);
debug.leaving();
},
call: function (payload) {
this.postData(
'http://some.url/',
payload)
.then(this.handleErrorsInResponse) // If I place a breakpoint here it works!
.then(this.handleReponse)
.catch(this.handleErrorsInFetch);
},
}
// Ultimately called by something like
comms = new Fetch();
someData = {"key": someJSON};
comms.call(someData);
Remove the wait on the response.
Replace
return await response.text();
by
return response.text();
I'm using both ApolloClient from 'apollo-client' and 'apollo-boost' libraries, like
const client = new ApolloClient({
uri: 'https://www.myapp.no/api/',
request: async (operation) => {
console.log(operation)
operation.setContext({
headers: {
authorization: tokenHeader,
'Content-Type': 'application/json'
}
})
},
onError: (error) => {
if (error.graphQLErrors) {
console.log('ApolloClient graphQLErrors')
console.log(graphQLErrors)
}
if (error.networkError) {
console.log('ApolloClient networkError')
console.log(graphQLErrors)
}
}
})
The operation object only show variables and query information. How to log the actual HTTP requests and response under the hood?
I want to see the outgoing request headers and params, and the responses headers and status code
This seems like a very simple task but I've spent quite some time searching without any mentions about this.
You can use this awesome extension: https://github.com/apollographql/apollo-client-devtools