Angular2 http response undefined

Question

This is my server data:

[
    {
        "name" : "testname"
    },
    {
        "name" : "testnametwo"
    }
]

I am trying to get this data using Angular2 http.get. I am trying with below code:

private _url : string = "appone/api/user.json"

    user = []

    constructor(private http : Http) { }

    getUsers() {
        let res = this.http.get(this._url).map((response : Response) => {
            return response.json()
        })
        res.subscribe((data) => {
            this.user = data
        })

        alert(this.user.name)
    }

But I didn't get any result. I don't know where I am wrong.

Any help is greatly appreciated.

Sangram Nandkhile · Accepted Answer · 2017-10-25 06:43:41Z

1

Your alert needs to be placed inside subscribe.

getUsers() {
        let res = this.http.get(this._url).map((response : Response) => {
            return response.json()
        })
        res.subscribe((data) => {
            this.user = data;
           alert(this.user.name); 
        })

    }

Explanation: Your API will probably take some time to return data and it will be called asynchronously. So your alert will be called even before your data has been returned by API.

Subscribe will be called only when it gets data from API so it is an appropriate place to log. Also, do consider logging errors as a good practice.

answered Oct 25, 2017 at 6:43

Sangram Nandkhile

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Comments

Andy Lamb · Accepted Answer · 2017-08-26 08:14:42Z

0

The code subscribes to the response and will set this.user when the the http.get returns asynchronously. So the alert will fire before the user is set.

answered Aug 26, 2017 at 8:14

Andy Lamb

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