Can't access property from POST response headers in Angular 4

Question

I'm trying to access CSRF Token received from POST response header, which I need to send back with every further request from my app. I'm was able to drill down the response stream until I could access the [[Entries]] which has the "csrfpreventionsalt" token. It gets displayed in console but when trying to access it shows as undefined.

Tried & Tested: I've tried the "get" method to access the header but it didn't work.

var csrf = res.headers.get('csrfpreventionsalt');

I've seen other questions on SO which say that you can't access the header value but If I can access the header in console then definately I should be able to access the token & assign it to a variable.

Solution to this might help others as well who could face the same situation in their apps. Any help is welcome !!

Answer 1

you need to map your response to get method like

this.http.get('…', { observe: 'response' });

as per new httpclient in angular, if you're still interested in the whole Response object you can observe for it

please check here

Answer 2

You can try the following :

Map.forEach((value: boolean, key: string) => {
    console.log(key, value);
});

Answer 3

I believe this question has already been asked on SO check this out

Angular 4.3.3 HttpClient : How get value from the header of a response?

I would have just put this in a comment but I don't have enough clout to comment just yet sorry

Answer 4

I was calling the get method after calling the json() method, basically I could get the csrf value after accessing it in the raw response object like below:

private extractLoginData = (res: Response) => {
    this.csrfToken = res.headers.get('csrfPreventionSalt');
    let body = res.json();
    return body;
}

Also make sure that you have your service has set the header fields as "*" for Access-Control-Allow-Headers & Access-Control-Allow-Origin.

Also add your "Access-Control-Allow-Credentials: true".