I am posting request to my backend server using fetch api in React js
const formData = new FormData();
formData.append("image", file);
formData.append("userId", currentUser.id);
formData.append("sliderNumber", sliderNumber);
const myHeaders = new Headers();
myHeaders.append("Content-Type", file.type);
myHeaders.append("Aceess-Control-Allow-Origin", "*");
fetch("http://localhost:4000/upload/slide-image", {
method: "POST",
headers: myHeaders,
mode: "no-cors",
body: formData
})
.then(response => response)
.then(data => console.log("Printing data: ", data));
};
In elixir backend
def upload(conn, params) do
# uploading code
#send response to the client with amazon s3 image url
send_resp(conn, 200, image_url)
end
but Response object from fetch api is empty
Response {
body: null
bodyUsed: false
headers: Headers {}
ok: false
redirected: false
status: 0
statusText: ""
type: "opaque"
url: ""
}
And it doesn't change when I respond with status code 400.
It seems like fetch api is not building Reponse object correctly in some point. Because I can find correct status code and response body in browser network tab. But Response object doesn't hold response from backend server.
Any idea?
If you are expecting a text response from your server, then on your first .then(.. you should do like:
fetch("http://localhost:4000/upload/slide-image", {
method: "POST",
headers: myHeaders,
mode: "no-cors",
body: formData
})
.then(response => response.text()) // <---
.then(data => console.log("Printing data: ", data));
fetch returns a Promise that resolves to a Response. When you use .text() at this stage, what you actually do is to take the Response stream, read it to completion and return a promise that will resolve with a text.
Aside from that, you also use mode: "no-cors" (as other users mentioned on their answers) that limits you in many ways. For example, even if you follow my instructions above, you will get an empty string, even if you are trying to return something from your server. And that will be because of this mode.
You can find more details about it here, under bullet no-cors.
Your Content-Type is wrong. When sending files along with other data, the Content-Type should still be multipart/form-data.
mode: "no-cors",
You set the mode to no-cors, so the response is Opaque, which means you can't see inside it.
Don't do that if you need to read the response.
Asides:
myHeaders.append("Content-Type", file.type);
That's the wrong content-type for a form data object. Don't set the content-type. The fetch API will set the correct one automatically.
myHeaders.append("Aceess-Control-Allow-Origin", "*");
Access-Control-Allow-Origin, which you misspelt, is a response header, not a request header.
.then(response => response)
Returning the response unchanged is rather pointless. You probably want response.text() if you are getting a plain URL back.
The accepted answer solved my pinpoint.
if you are expecting a JSON object from the backend, use
.then((response) => response.json())
Related
I have a React application where I am changing POST method to GET with the request body as it is. It works fine with POST request however when I change the method to GET, it gives me error-
message: "org.springframework.http.converter.HttpMessageNotReadableException: Required request body is missing: public
My Front End Code-
export const setData = (getData) => dispatch => {
axios({
method: 'GET',
url: 'http://localhost:8080/api',
headers: {
'Content-Type': 'application/json'
},
data: getData
})
.then (response => {
dispatch({
type: API_DATA,
payload: response.data
})
dispatch({
type: SET_SEARCH_LOADER,
payload: false
})
})
.catch(function(error) {
})
}
Can someone let me know what I am missing here. As per my understanding, http allows to have a request body for GET method.
As per my understanding, http allows to have a request body for GET method.
While this is technically true (although it may be more accurate to say that it just doesn't explicitly disallow it), it's a very odd thing to do, and most systems do not expect GET requests to have bodies.
Consequently, plenty of libraries will not handle this.
The documentation for Axois says:
// `data` is the data to be sent as the request body
// Only applicable for request methods 'PUT', 'POST', and 'PATCH'
Under the hood, if you run Axios client side in a web browser, it will use XMLHttpRequest. If you look at the specification for that it says:
client . send([body = null])
Initiates the request. The body argument provides the request body, if any, and is ignored if the request method is GET or HEAD.
If you want to send parameters with get request in axios, you should send parameters as params.
If you want to set "Content-type":"application/json" and send params with get request, you should also send an empty data object.
For example:
const AUTH_TOKEN = 'Bearer token'
const config = {
headers: {
'Content-Type': 'application/json',
'Accept': 'application/json',
'Authorization': AUTH_TOKEN,
},
data: {},
params: {
"post_id": 1
}
}
axios.get("http://localhost/api/v1/posts/", config)
This is not axios, the error origniates from the java backend you're talking to. The public field in your request body is missing.
If you just want to send the data as parameters (which would be odd), pass it using params instead of data (as shown here: https://github.com/axios/axios#example).
I personally don't think your API should support GET with a request body (talk to the devs and ask for documentation).
I read all over but couldn't find the answer.
When I use FormData(), it returns status 404 bad request.
However, if I pass the data (hardcoded) as in const requestBody (example below), it works perfectly.
This is my code:
var formData = new FormData();
formData.append("nickname", "johxns");
formData.append("password", "john_password");
formData.append("email", "john#server.com");
// If I do it this way, and assign this to body inside fetch, it works perfectly
// const requestBody = '{"nickname": "johxns","password":"john_password","email":"john#server.com"}';
fetch("http://localhost:5000/create_user", {
// if instead of formData, I assign requestBody to body, it works!
body: formData,
headers: {
"Content-Type": "application/json"
},
method: "POST"
}).then(function(response) {
return response.text();
}).then(function(data){
console.log('data', data);
}).catch(function(err){
console.err(err);
});
I already tried with URLSearchParams, but still couldn't make it work.
Thanks.
You shouldn't set the Content-Type header to application/json if you're not sending json. According to this answer, you don't need to set the Content-Type header.
body data type must match "Content-Type" header
Using Fetch
You should either send json data if you set Content-Type to application/json or not set any Content-Type if using FormData API since the fetch function is able to determine the correct Content-Type.
See here for more informations.
I have a React application where I am changing POST method to GET with the request body as it is. It works fine with POST request however when I change the method to GET, it gives me error-
message: "org.springframework.http.converter.HttpMessageNotReadableException: Required request body is missing: public
My Front End Code-
export const setData = (getData) => dispatch => {
axios({
method: 'GET',
url: 'http://localhost:8080/api',
headers: {
'Content-Type': 'application/json'
},
data: getData
})
.then (response => {
dispatch({
type: API_DATA,
payload: response.data
})
dispatch({
type: SET_SEARCH_LOADER,
payload: false
})
})
.catch(function(error) {
})
}
Can someone let me know what I am missing here. As per my understanding, http allows to have a request body for GET method.
As per my understanding, http allows to have a request body for GET method.
While this is technically true (although it may be more accurate to say that it just doesn't explicitly disallow it), it's a very odd thing to do, and most systems do not expect GET requests to have bodies.
Consequently, plenty of libraries will not handle this.
The documentation for Axois says:
// `data` is the data to be sent as the request body
// Only applicable for request methods 'PUT', 'POST', and 'PATCH'
Under the hood, if you run Axios client side in a web browser, it will use XMLHttpRequest. If you look at the specification for that it says:
client . send([body = null])
Initiates the request. The body argument provides the request body, if any, and is ignored if the request method is GET or HEAD.
If you want to send parameters with get request in axios, you should send parameters as params.
If you want to set "Content-type":"application/json" and send params with get request, you should also send an empty data object.
For example:
const AUTH_TOKEN = 'Bearer token'
const config = {
headers: {
'Content-Type': 'application/json',
'Accept': 'application/json',
'Authorization': AUTH_TOKEN,
},
data: {},
params: {
"post_id": 1
}
}
axios.get("http://localhost/api/v1/posts/", config)
This is not axios, the error origniates from the java backend you're talking to. The public field in your request body is missing.
If you just want to send the data as parameters (which would be odd), pass it using params instead of data (as shown here: https://github.com/axios/axios#example).
I personally don't think your API should support GET with a request body (talk to the devs and ask for documentation).
I'm making a POST request to a node.js server and I'm having trouble getting it to work. Here's my request:
const headers = {
'Accept': 'application/json',
'Content-Type': 'application/json',
'Authorization': 'this-can-be-anything',
};
export const postVote = (id, vote) =>
fetch(`${uri}/posts/${id}`, {
method: 'POST',
headers,
body: JSON.stringify({options: vote}),
}).then(response => response.json())
.then(data => data)
.catch(err => console.log(err));
The function accepts an 'id' and a 'vote', both strings. The id is being used as part of the URI in the request, and the vote is being supplied as options so the API knows what to do with it. Both of the arguments are being passed correctly:
id = '8xf0y6ziyjabvozdd253nd'
vote = 'upVote'
Here's a link to the GitHub repository for the server/API:
Udacity Readable API
and a screenshot of the network when firing the request:
UPDATE: Added the second screenshot which shows status 200. Though it shows this and appears to have been successful, it still doesn't post to the server and the information stays the same.
What you are looking at is the OPTIONS request in the network tab. For cross origin requests, every request if preceeded by an OPTIONS request which tells the calling client (browser, for example) if those HTTP methods are supported by the remote server for use in crosss origin context.
Check the other requests out. If the OPTIONS request was responded to correctly by the server, the browser must automatically follow up with your POST request
EDIT:
Also, the docs specify the param name to be option whereas in your screenshot it is coming up as options.
Further reading: CORS
Try declaring the headers as such:
var headers = new Headers({
'Content-Type': 'application/json',
'Authorization': 'this-can-be-anything',
})
For some reason, I can't get file transfers to work via fetch. My code is really simple:
export function updateProfilePicture(apiKey, userID, picture) {
let data = new FormData();
data.append('picture', picture);
return fetch(`${API_URL}/v1/${ROOT}/update_profile_picture/${userID}`,{
headers: {'Authorization': `Token token=${apiKey}`},
method: 'POST',
data: data
}).then(response => response.json());
}
However, the resulting request does not seem to include any file whatsoever. Am I missing something? In the above example, picture is instance an of File
There could be two reasons:
data field in Fetch API is called body. Use this instead of data property.
(optional) You need to add another header: 'Content-Type', 'multipart/form-data'
Read more about Fetch API:
https://developers.google.com/web/updates/2015/03/introduction-to-fetch?hl=en
https://developer.mozilla.org/en/docs/Web/API/Fetch_API
Fetch polyfill