How to enable fetch POST in chrome extension contentScript? - google-chrome

Question

I'm trying to call REST API in chrome extension. I managed to get fetch GET working , but couldn't make POST work. The body on server side is always empty. Here is my fetch request:
let url = "http://localhost:3000/api/save/one"
fetch(url, { method: "POST", headers: { "Accept": "application/json", "Content-Type": "application/json; charset=utf-8" }, mode: "no-cors", body: JSON.stringify(json) })
.then(resp => console.log(resp))
When I examined the request on server, I did notice that the content-type on server is always "text/plain;charset=UTF-8". So, my headers doesn't seem to be passed over. However, "Accept" header did go through.
This is the headers on server:
accept:"application/json"
accept-encoding:"gzip, deflate, br"
accept-language:"en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7"
cache-control:"no-cache"
connection:"close"
content-length:"306"
content-type:"text/plain;charset=UTF-8"
If I remove "Accept" from my fetch headers, I got this on server:
accept:"*/*"
accept-encoding:"gzip, deflate, br"
accept-language:"en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7"
cache-control:"no-cache"
connection:"close"
content-length:"306"
content-type:"text/plain;charset=UTF-8"
Any explanation on this? So, how to make POST work?

Answer 1

You need to write the code for post method
Listener
background.js:
chrome.runtime.onMessage.addListener(function (request, sender, sendResponse) {
if (request.contentScriptQuery == "getdata") {
var url = request.url;
fetch(url)
.then(response => response.text())
.then(response => sendResponse(response))
.catch()
return true;
}
if (request.contentScriptQuery == "postData") {
fetch(request.url, {
method: 'POST',
headers: {
'Accept': 'application/json, application/xml, text/plain, text/html, *.*',
'Content-Type': 'application/x-www-form-urlencoded; charset=utf-8'
},
body: 'result=' + request.data
})
.then(response => response.json())
.then(response => sendResponse(response))
.catch(error => console.log('Error:', error));
return true;
}
});
Caller
Content_script.js
chrome.runtime.sendMessage(
{
contentScriptQuery: "postData"
, data: JSONdata
, url: ApiUrl
}, function (response) {
debugger;
if (response != undefined && response != "") {
callback(response);
}
else {
debugger;
callback(null);
}
});