How do you add CORS headers in Redstone interceptor?

Question

I\'m trying to add CORS headers to incoming requests but I\'ve noticed that app.response.headers is an immutable map and app.request.response doesn\'t

Answer 1

I found the fix in the first piece of code inside the Interceptor documentation...:)

@app.Interceptor(r"/api/.*", chainIdx: 1)
corsInterceptor() {
    if (app.request.method == "OPTIONS") {
        var response = new shelf.Response.ok("", headers: HEADERS);
        app.chain.interrupt(statusCode: HttpStatus.OK, responseValue: response);
    } else {
        app.chain.next(() => app.response.change(headers: HEADERS));
    }
}

app.chain.next() can take a callback as argument, which is expected to return a Response object. In this case app.response.change() returns a response with the correct headers.