CORS with Dart, how do I get it to work?
Pregunta
Just started tinkering with Dart and I decided to write a simple Http Server and a client. My server code:
#import("dart:io");
final HOST = "127.0.0.1";
final PORT = 8080;
final LOG_REQUESTS = true;
void main() {
HttpServer server = new HttpServer();
server.addRequestHandler((HttpRequest request) => true, requestReceivedHandler);
server.listen(HOST, PORT);
print("Server is running on ${PORT}.");
}
void requestReceivedHandler(HttpRequest request, HttpResponse response) {
var pathname = request.uri;
var apiresponse="";
if (LOG_REQUESTS) {
print("Request: ${request.method} ${pathname}");
}
if(pathname == '/api'){
response.headers.set(HttpHeaders.CONTENT_TYPE, "text/plain; charset=UTF-8");
response.headers.add("Access-Control-Allow-Methods", "POST, OPTIONS, GET");
response.headers.add("Access-Control-Allow-Origin", "*");
response.headers.add('Access-Control-Allow-Headers', '*');
print('welcome to the good life');
response.outputStream.writeString("API Call");
response.outputStream.close();
}
}
My client code:
#import('dart:html');
#import('dart:json');
class dartjson {
dartjson() {
}
void run() {
write("Hello World!");
}
void fetchFeed(){
XMLHttpRequest xhr = new XMLHttpRequest();
var url = "http://127.0.0.1:8080/api";
xhr.open("GET", url, true);
xhr.setRequestHeader('Content-Type', 'text/plain');
//xhr.setRequestHeader('Access-Control-Request-Headers', 'http://127.0.0.1:3030');
xhr.send();
print(xhr.responseText);
document.query('#status').innerHTML = xhr.responseText;
}
void main() {
new dartjson().fetchFeed();
}
I keep getting the error:
XMLHttpRequest cannot load http://127.0.0.1:8080/api. Origin
http://127.0.0.1:3030 is not allowed by Access-Control-Allow-Origin.
What I'm I doing wrong?
Solución
you could simplify your life and run both server/client scripts from the same host:port address. There is a small webserver example at http://www.dartlang.org/articles/io/#web-servers that serves static files too. Add your '/api' handler and make sure your client files are in the same directory. The example server is a lot slower than the Dart Editor builtin server that runs on port 3030.
Otros consejos
Was facing the same problem. Below is my server code. It just prints the query parameters. Added access control headers to fix the issue.
HttpServer.bind('127.0.0.1', 8080).then((server){
server.listen((HttpRequest request){
request.uri.queryParameters.forEach((param,val){
print(param + '-' + val);
});
request.response.headers.add("Access-Control-Allow-Origin", "*");
request.response.headers.add("Access-Control-Allow-Methods", "POST,GET,DELETE,PUT,OPTIONS");
request.response.statusCode = HttpStatus.OK;
request.response.write("Success!");
request.response.close();
});
});
Hope this helps.
here is my solution:
request.response.headers.add("Access-Control-Allow-Origin", "*");
request.response.headers.add("Access-Control-Allow-Headers", "*");
request.response.headers.add("Access-Control-Allow-Methods", "POST,GET,DELETE,PUT,OPTIONS");