I have simple website I'm building with AngularJS which calls an API for json data.
However I am getting Cross domain origin problem is there anyway around this to allow for cross domain requests?
Error:
XMLHttpRequest cannot load http://api.nestoria.co.uk/api?country=uk&pretty=1&action=search_listings&place_name=soho&encoding=json&listing_type=rent. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http:// localhost' is therefore not allowed access.
searchByPlaceName: function() {
var url = baseurl+'country=uk&pretty=1&action=search_listings&place_name=london'+encoding+type;
return $http.get(url);
}
It seems that api.nestoria.co.uk does not allow CORS. It has to set the Access-Control-Allow-Origin header itself -- you have no direct control over that.
However, you can use JSONP. That site allows it via the callback query parameter.
$http.jsonp(baseurl+'country=uk&pretty=1&action=search_listings&place_name=london'
+encoding+type + "&callback=JSON_CALLBACK")
Install Fiddler. Add a custom rule to it:
static function OnBeforeResponse(oSession: Session)
{
oSession.oResponse.headers.Add("Access-Control-Allow-Origin", "*");
}
This would allow you to make cross domain requests from localhost. If the API is HTTPS make sure you enable 'decrypt HTTPS traffic' in fiddler.
Reference
-------------------- UPDATE
The response you are getting is JSON. Specifying JSONP as datatype would not work. When you do specify JSONP the return should be a function not JSON object.
JSONP
Related
I want to post my contact form to my google script that will send an e-mail to me. I use the following code:
var TO_ADDRESS = "example#gmail.com"; // where to send form data
function doPost(e) {
var callback = e.parameter.callback;
try {
Logger.log(e); // the Google Script version of console.log
MailApp.sendEmail(TO_ADDRESS, "Contact Form Submitted",
JSON.stringify(e.parameters));
// return json success results
return ContentService
.createTextOutput(callback+
JSON.stringify({"result":"success",
"data": JSON.stringify(e.parameters) }))
.setMimeType(ContentService.MimeType.JSON);
} catch(error) { // if error return this
Logger.log(error);
return ContentService
.createTextOutput(callback+JSON.stringify({"result":"error",
"error": e}))
.setMimeType(ContentService.MimeType.JSON);
}
}
When i try to post to the google script url, i get the following error:
Access to XMLHttpRequest at
'https://script.google.com/macros/s/~~myscriptid~~/exec' from origin
'http://localhost:4200' has been blocked by CORS policy: Response to
preflight request doesn't pass access control check: No
'Access-Control-Allow-Origin' header is present on the requested
resource.
I have no clue how to add the CORS-filter to my google script.
I know the script is working i have tested it with this plugin:
https://chrome.google.com/webstore/detail/allow-control-allow-origi/nlfbmbojpeacfghkpbjhddihlkkiljbi
Late answer, but totally working...
To pass data from appscripts to another website, just use mime type JAVASCRIPT on appscripts side, like so:
doGet(e){
return ContentService
.createTextOutput(e.parameter.callback + "(" + JSON.stringify(YOUR OBJECT DATA HERE)+ ")")
.setMimeType(ContentService.MimeType.JAVASCRIPT);
}
And on the front end access it as:
<script>
var url = "https://script.google.com/macros/s/AKfy*****ACeR/exec?callback=loadData";
// Make an AJAX call to Google Script
jQuery.ajax({
crossDomain: true,
url: url,
method: "GET",
dataType: "jsonp"
});
// log the returned data
function loadData(e) {
console.log(e);
}
</script>
This works without any CROB/ CROS headache
After a lot of hard work, the only solution which worked for me:
In Google Apps Script
function doPost(e) {
return ContentService.createTextOutput(JSON.stringify({status: "success", "data": "my-data"})).setMimeType(ContentService.MimeType.JSON);
}
In JavaScript
fetch(URL, {
redirect: "follow",
method: "POST",
body: JSON.stringify(DATA),
headers: {
"Content-Type": "text/plain;charset=utf-8",
},
})
Note the attribute redirect: "follow" that is very important;
Quick answer
You (frontend developer) can't fix cors error from remote server. Only the owner of the remote server (google app script server) could do it.
Workaround 1 (GET)
Use only GET method in app script. Get method will not throw CORS errors, no matter where you consume it from: csr, spa, frontend, react, angular, vue, jquery, pure javascript, etc
Workaround 2 (Backend)
If you are in the backend server (java, php, c#, node, ruby, curl, etc) not in the frontend (browser, react, angular, vue), you could consume any method published on google apps script.
CORS don't affect when the consumption is at the backend layer
So if only use get endpoints are not an option for you, you could use another server language (java, nodejs, php, etc) to consume the Post google app script, and return that information to your web
Explanation
Let's imagine this script with 02 methods deployed as web in google app script
function doGet(e) {
var response = {
"code": 200,
"message": "I'm the get"
};
return ContentService.createTextOutput(JSON.stringify(response)).setMimeType(ContentService.MimeType.JSON);
}
function doPost(e) {
var response = {
"code": 200,
"message": "I'm the post"
};
return ContentService.createTextOutput(JSON.stringify(response)).setMimeType(ContentService.MimeType.JSON);
}
and url like this after the deployment:
https://script.google.com/a/utec.edu.pe/macros/s/AKfy\*\*\*\*\*\*eo/exec
In the backend
You could consume the POST and GET methods without any problems with any language: java, nodejs, python, php, c#, go , etc and/or with any http client like postman, insomnia, soapui, curl, etc
In the frontend (js in the browser)
I was not able to consume the POST method. I tried with jsonp and other crazy attempts and the error was the same:
Cross-Origin Request Blocked: The Same Origin Policy disallows
reading the remote resource at
https://script.google.com/a/utec.edu.pe/macros/s/AKfy***A4B***eo/exec?foo=bar
(Reason: CORS header ‘Access-Control-Allow-Origin’ missing).
So for any reason, the google server don't allow us to use POST operations from javascript side (2021)
In the frontend : GET Method
Only GET method worked for me. I will assume that google configuration at server layer has some CORS permission only for GET method.
The following ways worked for me, from a simple js to an advanced frameworks like react, vue or angular:
axios
const axios = require('axios');
axios.get('https://script.google.com/a/acme.org/macros/s/AKfy***A4B***eo/exec').then(resp => {
console.log(resp.data);
});
$.getJSON
$.getJSON('https://script.google.com/a/acme.org/macros/s/AKfy***A4B***eo/exec?foo=bar', function(result) {
console.log(result);
});
XMLHttpRequest
var xmlhttp = new XMLHttpRequest();
var theUrl = "https://script.google.com/a/acme.org/macros/s/AKfy***A4B***eo/exec?foo=bar";
xmlhttp.open("GET", theUrl);
xmlhttp.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
xmlhttp.send();
CORS : Cross-origin resource sharing
A lot of developers don't understand what is CORS. It is not easy to understand. Commonly the developer fix the error at the server layer and don't invest time (or don't let him) to understand what CORS is:
https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS
https://portswigger.net/web-security/cors
https://youtu.be/4KHiSt0oLJ0
If you don't have time, check my definition, extreme summary bordering on wrong:
CORS is a protection offered by trusted browsers to avoid that a web acme.com can load in the background(ajax/js) an http resource from another domain like hacker-api.com/foo/bar
But if acme.com and hacker-api.com/foo/bar are developed by you and/or hacker-api.com/foo/bar is designed to be consumed by any web of the world, you could fix it at server layer
How to fix CORS errors?
Are very common and simple to control with a few lines in the server if the server belongs to us, but since we don't have control over the server(google), we can not do anything at this layer.
Here some samples of CORS configuration to allow consumption from webs is the backend server belongs to you:
java sample:
//only http://acme.com could consume my api
#CrossOrigin("http://acme.com")
#RequestMapping(method = RequestMethod.GET, "/{id}")
public Account retrieve(#PathVariable Long id)
nodejs sample:
//only http://localhost:8080 could consume my api
var corsOptions = {
origin: 'http://localhost:8080',
optionsSuccessStatus: 200 // For legacy browser support
}
app.use(cors(corsOptions));
//any web could consume my api
origin : "*"
I ran into the same issue while trying to create an application that logs data and retrieves log sections to/from a google sheet through Google Apps Script using Get and Post requests.
I did find a solution that may or may not be helpful to some people.
From the Google Docs:
There are two types of CORS requests: simple and preflighted. A simple
request can be initiated directly. A preflighted request must send a
preliminary, "preflight" request to the server to get permission
before the primary request can proceed. A request is preflighted if
any of the following circumstances are true:
It uses methods other than GET, HEAD or POST. It uses the POST method
with a Content-Type other than text/plain,
application/x-www-form-urlencoded, or multipart/form-data. It sets
custom headers. For example, X-PINGOTHER.
All I did was change the content type of my Get and Post requests
var request = new window.XMLHttpRequest();
request.open(opts.method, opts.url, true);
request.setRequestHeader("Content-Type", "text/plain");
And within the google script, parse to JSON to be used
function doPost(e) {
const d = JSON.parse(e);
...
As far as I understood you have application to be run on custom domain. And it should access script on google cloud.
The bad news: there are no way to skip CORS check on your application side(until request is simple that I believe is not your case).
You should specify Access-Control-Allow-Origin on Google Cloud side:
Cloud Storage allows you to set CORS configuration at the bucket level only. You can set the CORS configuration for a bucket using the gsutil command-line tool, the XML API, or the JSON API. For more information about setting CORS configuration on a bucket, see Configuring Cross-Origin Resource Sharing (CORS). For more information about CORS configuration elements, see Set Bucket CORS.
You can use either of the following XML API request URLs to obtain a response from Cloud Storage that contains the CORS headers:
storage.googleapis.com/[BUCKET_NAME]
[BUCKET_NAME].storage.googleapis.com
If this does not help for any reason you will need to get your own server working as a proxy:
your client application <-> your backend that returns Access-Control-Allow-Origin <-> google cloud
Well after several attempts, I was able to send the data through a web app form in angular 8.
The solution is simple, within "HttpClient.post" you can enter a third parameter to establish an HTTP connection header this for "https://script.google.com" may not be correct and will end with an http connection failed by CORS security.
Just don't add the HTTP connection header as the third parameter of HttpClient.post
const object = {
title: 'Prices',
phone: '999999999',
full_name: 'Jerson Antonio',
email: 'test#example.com',
message: 'Hello, .......'
};
return this.http.post(this.API_REST_FORM, JSON.stringify(object));
In App script always use New deployment to deploy the script.
Otherwise it will use old script and you will get CORS error
The CORS error is most probably caused by a fatal error in your Google Apps Web App script. In this case the Google error handling system displays a human-readable HTML page that does not contain CORS headers.
In my case I got the following error page:
I am doing post request to API via Azure ApiManagement.
If Origin header is present and its not one of specified in Cors policy even postman will return empty response.
As soon as I disable Origin header I can get response.
So problem is following for web based application we must enable cors,
<cors allow-credentials="true">
<allowed-origins>
${env:CorsOrigin}
</allowed-origins>
<allowed-methods>
<method>*</method>
</allowed-methods>
<allowed-headers>
<header>*</header>
</allowed-headers>
</cors>
But our cordova app is also calling same api, and by default cordova will append Origin: file:// Then Api management is doing strange things it will cut body. So response will be empty. If i do same request directly to azure function, I will get proper response back, and since cordova does not care (To a degree in our case is ok) about CORS I would expect api management not to cut response.
Also Api management will not allow me to enter *, because of allow-credentials="true" and also I can't set it to allow file://
APIM does not support origin with file scheme, only http and https. I'll see if we can fix it. But there the workaround for allow-origins=* and allow-credentials=true is to use expressions:
<allowed-origins>
<origin>#(context.Request.Headers.GetValueOrDefault("Origin", "*"))</origin>
</allowed-origins>
This way response will contain sent Origin header value in Access-Control-Allow-Origin and not just * which is not allowed.
I am attempting to retrieve some data from a 3rd party domain. When I enter the request url. I am able to see the data I requested. But when I attempt to make a call using ajax (to a different domain), it returns the error message. Why am I not able to retrieve the data? Might it have something to do with cross-domain policy and not using jsonp? Here is my code:
<script>
$(document).ready(function() {
$.ajax ({
type: 'GET',
url: 'https://crm.zoho.com/crm/private/json/Potentials/searchRecords?authtoken=xxx&scope=crmapi&criteria=(((Potential%20Email:test2#email.com))&selectColumns=Potentials(Potential%20Name)&fromIndex=1&toIndex=1',
dataType: 'json',
success: function(test) {
alert(JSON.stringify(test));
},
error: function(test) {
alert(JSON.stringify(test));
}
});
});
</script>
Because the request that you has send is blocked by the browser. When you perform a request using an object XmlHttpRequest and obviously javascript, the browser applied cross-domain policy, defined in WC3, and thus verify in url the origin and target domain (protocol, host and port), if those elements are in different domain (i.e. host and port), then the request never comes out from browser (a.k.a User Agent). You can use jsonp to "break" or "jump" this policy, simply is a tag "script" with a resource (src) defined in a different domain using a parameter called "jsonCallback=?" added in query string, who really receives the data in format json. This is more ugly and have a security risk, therefore never be used.
The other method is to use and enable a "technique" (is more than that) known like "CORS" (Cross Origin Request Sharing), where the client (browser) and server (resource at different domain), send, exchange and negotiate an Http Headers to secure that who send and who received are authorized to exchange information. The basics steps to realize CORS is:
Explicity define in client (ajax-jquery) that CORS will be used in request, specifying CrossDomain:true. This will enable HTTP Headers defined in CORS
Specify in the HTTP Server, a HTTP Header indicating the Domain Source that have permissions to call a resource hosted in server. The most general header can be defined like: Access-Control-Allow-Origin , with value asigned a domain, like "*" (all domain authorized) (Access-Control-Allow-Origin, *)
In some Browsers, sometimes they send a http header request called "preflight request", is like a discover via to know if the server is prepared to recieve cross-origin request. This Http Header contains a "Method HTTP" value or "Verb HTTP" (like PUT,POST,GET,DELETE) assigned to "OPTIONS", then the server must be configured too to recieve HTTP Headers with Method "OPTIONS", and therefore allow methods http like PUT, DELETE,POST or GET. In generals terms the server must have this headers when in the request had a method HTTP "OPTIONS":
Access-Control-Allow-Methods , "POST, PUT, DELETE, GET, OPTIONS"
Access-Control-Allow-Headers, ", "Content-Type, Accept"
Finally, the client (ajax) will recieve the data from the server.
This sounds a little confusing and the steps are few, sorry that not put a code like examples, but, really CORS is not hard to understand.
I hope this will help.
References from Mozilla:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS
This show what is CORS and you can use in configuration server:
http://enable-cors.org/
I have a frontend in AngularJs and a playframework 2 Scala backend. Looking at this to add CORs to the backend - I have two endpoints a GET and POST
GET /api/question/:id controllers.Questions.getQuestion(id: String)
POST /api/question/:id controllers.Questions.postQuestion(id: String)
This solution provided in the other response works for the GET but not for the POST
def getQuestion(key:String) = CorsAction{
....
}
def postQuestion(key:String) = CorsAction(parse.json){
req =>
........
}
What I understood is that the CORsAction (which extends ActionBuilder) can also accept methods which a bodyparser and thus should essentially work for POST requests as well.
This is what I see in the browser console when i hit POST from my front end.
OPTIONS http://localhost:9000/api/question/abc123 No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:3001' is therefore not allowed access. angular.js:7997
XMLHttpRequest cannot load http://localhost:9000/api/question/abc123. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:3001' is therefore not allowed access.
So I'm not sure the exact problem but adding the following to the routes
fixed the problem
OPTIONS /api/question/:id controllers.Application.preflight(id)
Where the preflight endpont just returns Ok with the CORs headers. But I would have thought that the CorsAction was supposed to take care of this. Anyways, moving on.
I have a web application for iPhone, which will ultimately run within a PhoneGap application - but for now I'm running it in Safari.
The application needs to access tweets from Twitter friends, including private tweets. So I've implemented OAuth using the Scribe library. I successfully bounce users to Twitter, have them authenticate, then bounce back.
At this point the web app has oAuth credentials (key and token) which it persists locally. From here on I'd like it to user the Twitter statuses/user_timeline.json method to grab tweets for a particular user. I have the application using JSONP requests to do this with unprotected tweets successfully; when it accesses the timeline of a private Twitter feed, an HTTP basic authentication dialog appears in the app.
I believe that I need to provide the OAuth credentials to Twitter, so that my web application can identify and authenticate itself. Twitter recommends doing so through the addition of an HTTP Authorization header, but as I'm using JSONP for the request I don't think this is an option for me. Am I right in assuming this?
My options therefore appear to either be putting the oAuth credentials as query-string parameters (which Twitter recommends against, but documentation suggests still supports); or proxying all the Tweets through an intermediate server. I'd rather avoid the latter.
I access the Twitter API using URLs of the form
http://api.twitter.com/1/statuses/user_timeline.json?user_id=29191439&oauth_nonce=XXXXXXXXXXX&oauth_signature_method=HMAC-SHA1&oauth_timestamp=1272323042&oauth_consumer_key=XXXXXXXXXX&oauth_signature=XXXXXXXXXX&oauth_version=1.0
When user_id is a public user, this works fine. When user_id is a private user, I get that HTTP Basic Auth dialog. Any idea what I'm doing wrong? I'm hoping it's something embarrassingly simple like "forgetting an important parameter"...
The oAuth stanza needs to be exact, as per http://dev.twitter.com/pages/auth#auth-request - I ended up building an Authorization: header that I could first check with curl.
I built it using the really helpful interactive request checker at http://hueniverse.com/2008/10/beginners-guide-to-oauth-part-iv-signing-requests/
Here's a friends API request for a protected user:
curl -v -H 'Authorization: OAuth realm="https://api.twitter.com/1/friends/ids.json", oauth_consumer_key="XXXXXXXXXXXXXXXX", oauth_token="XXXXXXXXXXXXXXXX", oauth_nonce="XXXXXXXXXXXXXXXX", oauth_timestamp="1300728665", oauth_signature_method="HMAC-SHA1", oauth_version="1.0", oauth_signature="XXXXXXXXXXXXXXXX%3D"' https://api.twitter.com/1/friends/ids.json?user_id=254723679
It's worth re-iterating that as you've tried to do, instead of setting the Authorization header via e.g. jquery's beforeSend function, that for cross-domain JSONP requests (which can't add HTTP headers) you can make oAuth requests by putting all the relevant key/value pairs in the GET request. This should hopefully help out various other questioners, e.g
Set Headers with jQuery.ajax and JSONP?
Modify HTTP Headers for a JSONP request
Using only JQuery to update Twitter (OAuth)
Your request looks like it has a couple of problems; it's missing the user's oauth_token plus the oauth_signature doesn't look like it has been base64 encoded (because it's missing a hex encoded = or ==, %3 or %3D%3D respectively).
Here's my GET equivalent using oAuth encoded querystring params, which you can use in a cross-domain JSONP call:
https://api.twitter.com/1/friends/ids.json?user_id=254723679&realm=https://api.twitter.com/1/friends/ids.json&oauth_consumer_key=XXXXXXXXXXXXXXXX&oauth_token=XXXXXXXXXXXXXXXX&oauth_nonce=XXXXXXXXXXXXXXXX&oauth_timestamp=1300728665&oauth_signature_method=HMAC-SHA1&oauth_version=1.0&oauth_signature=XXXXXXXXXXXXXXXX%3D
I was struggling with similar problem of making JSONP requests from Jquery, the above answer helped just to add what I did to achieve my solution.
I am doing server to server oauth and then I send oauth token, secret, consumer key and secret (this is temporary solution by the time we put a proxy to protect consumer secret). You can replace this to token acquiring code at client.
Oauth.js and Sha1.js download link!
Once signature is generated.
Now there are 2 problems:
JSONP header cannot be edited
Signed arguments which needs to be sent as part of oauth have problem with callback=? (a regular way of using JSONP).
As above answer says 1 cannot be done.
Also, callback=? won't work as the parameter list has to be signed and while sending the request to remote server Jquery replace callback=? to some name like callback=Jquery1232453234. So a named handler has to be used.
function my_twitter_resp_handler(data){
console.log(JSON.stringify(data));
}
and getJSON did not work with named function handler, so I used
var accessor = {
consumerSecret: XXXXXXXXXXXXXXXXXXXXXX,
tokenSecret : XXXXXXXXXXXXXXXXXXXXXX
};
var message = { action: "https://api.twitter.com/1/statuses/home_timeline.json",
method: "GET",
parameters: []
};
message.parameters.push(['realm', "https://api.twitter.com/1/statuses/home_timeline.json"]);
message.parameters.push(['oauth_version', '1.0']);
message.parameters.push(['oauth_signature_method', 'HMAC-SHA1']);
message.parameters.push(['oauth_consumer_key', XXXXXXXXXXXXXXXX]);
message.parameters.push(['oauth_token', XXXXXXXXXXXXXXX]);
message.parameters.push(['callback', 'my_twitter_resp_handler']);
OAuth.completeRequest(message, accessor);
var parameterMap = OAuth.getParameterMap(message.parameters);
Create url with base url and key value pairs from parameterMap
jQuery.ajax({
url: url,
dataType: "jsonp",
type: "GET",
});