nodejs - first argument must be a string or Buffer - when using response write with http request

Question

I m simply trying to create a node server that outputs the HTTP status of a given URL   When I try to flush the response with res write  I get the error  throw new TypeError  first argument must be a string or Buffer     But if I replace them with console log  everything is fine  but I need to write them to the browser not the console    The code is  var server   http createServer function  req  res        res writeHead 200    Content-Type    text plain          request           uri   http   www google com           method   GET           maxRedirects 3        function error  response  body            if   error                res write response statusCode             else                 response end error               res write error                               res end        server listen 9999     I believe I should add a callback somewhere but pretty confused and any help is appreciated

User · Answer

response statusCode is a number  e g  response statusCode     200  not  200   As the error message says  write expects a string or Buffer object  so you must convert it   res write response statusCode toString       You are also correct about your callback comment though  res end    should be inside the callback  just below your write calls

User · Answer

And there is another possibility  not in this case  when working with ajax XMLhttpRequest   while sending information back to the client end you should use res send responsetext  instead of res end responsetext

User · Answer

The first argument must be one of type string or Buffer  Received type object    at write     I was getting like the above error while I passing body data to the request module   I have passed another parameter that is JSON  true and its working   var option   url  https   myfirstwebsite v1 appdata   json true  body  name  xyz  age 30   headers   my credential   rp option   then  res   gt   res send  response res       catch  error   gt   res send  response error

User · Answer

Well  obviously you are trying to send something which is not a string or buffer     It works with console  because console accepts anything  Simple example   var obj     test    test     console log  obj       works res write  obj       fails   One way to convert anything to string is to do that   res write       obj      whenever you are trying to send something  The other way is to call  toString   method   res write  obj toString         Note that it still might not be what you are looking for  You should always pass strings buffers to  write without such tricks   As a side note  I assume that request is a asynchronous operation  If that s the case  then res end    will be called before any writing  i e  any writing will fail anyway   because the connection will be closed at that point    Move that line into the handler   request       uri   http   www google com       method   GET       maxRedirects 3    function error  response  body        if   error            res write response statusCode         else             response end error           res write error             res end

User · Answer

Although the question is solved  sharing knowledge for clarification of the correct meaning of the error    The error says that the parameter needed to the concerned breaking function is not in the required format i e  string or Buffer  The solution is to change the parameter to string  breakingFunction JSON stringify offendingParameter       other params        or buffer  breakingFunction BSON serialize offendingParameter       other params

User · Answer

Request takes a callback method  its async  So I am assuming  by the time the callback is executed the res end   might get called  Try closing the request within the callback

User · Answer

if u want to write a JSON object to the response then change the header content type to application json  response writeHead 200    Content-Type    application json     var d   new Date parseURL query iso   var postData          hour    d getHours         minute    d getMinutes         second    d getSeconds     response write postData  response end

User · Answer

I get this error message and it mentions options body  I had this originally  request post       url  apiServerBaseUrl     v1 verify       body            email  req user email             I changed it to this   request post       url  apiServerBaseUrl     v1 verify       body  JSON stringify           email  req user email              and it seems to work now without the error message   seems like bug though   I think this is the more official way to do it    request post           url  apiServerBaseUrl     v1 verify           json  true          body                email  req user email

[node.js] nodejs - first argument must be a string or Buffer - when using response.write with http.request

Examples related to node.js

Examples related to http

Examples related to callback