Issue with Ionic 2 where headers are not being properly set before making an HTTP request

I am currently working on a request to my backend system that involves setting up headers and tokens. The code I have written for this process is as follows:

loggedIn() {
    let headers = new Headers();
    headers.append('Content-Type', 'application/json');
    this.getToken().then((val) => {
        headers.append('X-Auth-Token', val);
    });
    const options = new RequestOptions({headers: headers});
    let seq = this.api.post('/login', null, options).share();
    seq.map((res: Response) => res.json())
        .subscribe(res => {

        }, err => {
            console.log("HEADERS ------- ", options.headers);
        });
    return seq;
};

However, I have encountered an issue where sometimes the 'X-Auth-Token' header is not being set. I need to find a way to ensure that the header is always being properly set. Any suggestions on how to achieve this?

The implementation of the getToken() function is shown below:

getToken() {
    return this.storage.get('token').then((value) => {
        return value;
    });
}

Finally, here is how the method checkIfLoggedIn(), which triggers the loggedIn() function, looks like:

checkIfLoggedIn() {
    this.user.loggedIn()
        .subscribe((res) => {
            console.log("LoginPage RETURN VALUE --------------- ", res);
        }, (err) => {
            console.log("LoginPage RETURN ERROR --------------- ", err);
        });
}

Answer №1

Make sure to update your code so that the API post request includes data after the header.

loggedIn() {
    let headers = new Headers();
    headers.append('Content-Type', 'application/json');
    this.getToken().then((val) => {
        headers.append('X-Auth-Token', val);
         const options = new RequestOptions({headers: headers});
         let seq = this.api.post('/login', null, options).share();
         seq.map((res: Response) => res.json())
            .subscribe(res => {

            }, err => {
                console.log("HEADERS ------- ", options.headers);
            });
        return seq;
    });

};

Answer №2

I encountered a similar issue while working with Ionic 3, and it was due to the asynchronous nature of JavaScript code. After some research, I came across a solution in another Stack Overflow post that may be helpful in resolving this problem.

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