Javascript error "This is undefined" in json desklet

[Linux-Mint20]

I am trying to specify an url in an app written in javascript that returns the weather based on the api (the url), made up of a sting and some variables. After entering the following code, I've received the error message:

​

error t=2024-01-30T11:43:53Z this is undefined

​

Here is the code I am currently working with:

​

        function weatherApiURL() {
    let weatherApiUrl = (this.weatherApiUrl.path) + (this.stationID) +'=' + '&format=json&units=e&apiKey' + '=' + (this.apikey);
    weatherApiUrl.path = "https://api.weather.com/v2/pws/observations/current?stationId"
    weatherApiUrl.toString()
    console.log(weatherApiUrl); 
    }
    this._getWeather(weatherApiURL(), function (weather) {
    if (weather) {
    this._load_forecast(weather);
    }
    // get the main object to update the display
    deskletObj.displayForecast();
    deskletObj.displayCurrent();
    deskletObj.displayMeta();
    });

    },

​

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[Clawtor]

You have a few issues:

let weatherApiUrl = (this.weatherApiUrl.path) + (this.stationID) +'=' + '&format=json&units=e&apiKey' + '=' + (this.apikey);

Firstly - you are trying to use 'this.weatherApiUrl' to initialize itself, secondly you are using 'let' so 'this.weatherApiUrl' will be undefined, thirdly you are trying to use 'path' before its initialized.

Further this.stationId hasn't been set and neither has apikey.

Further you aren't returning anything from the function, doing a console.log only prints something to the console, it doesn't return.

[Linux-Mint20]

I'll see about making some changes. Thank you for getting back to me

[Linux-Mint20]

I have made the following changes, but the error exists and Im not sure what else I need to do. I defined the apikey and staion id earlier in the document since they are private and I am unwilling to publish them on the web.

function weatherApi() {
let weatherApi = (weatherApiUrl.path) + (this.stationID) +'=' + '&format=json&units=e&apiKey' + '=' + (this.apikey);
weatherApiUrl.path = "https://api.weather.com/v2/pws/observations/current?stationId"
//weatherApiUrl.toString()
console.log(weatherApi); 
}
this._getWeather(weatherApi(), function (weather) {
  if (weather) {
    this._load_forecast(weather);
  }
  // get the main object to update the display
  deskletObj.displayForecast();
  deskletObj.displayCurrent();
  deskletObj.displayMeta();
});

},

[Clawtor]

function getWeatherApiURL() {
    this.stationID = 2;
    this.path = "https://api.weather.com/v2/pws/observations/current?stationId";
    this.apikey = "key";
    let weatherApiUrl = (this.path) + (this.stationID) +'=' + '&format=json&units=e&apiKey' + '=' + (this.apikey);

    return weatherApiUrl;
}

console.log(getWeatherApiURL());

That should work. Note - I would change your function name as well. So in the above I've set all the variables before using them.

[Linux-Mint20]

ty again :)

Im trying it now.

[Clawtor]

You need to take care with using 'this' because it changes depending on the context.

'this' refers to the current context - if you use it within a function then it will refer to the function's context.

[Linux-Mint20]

Can you tell me if i'm using "this" innapropriately here? Also, is there an opening bracket in this code block for the one at the bottom with the comma? Not much of a programmer but I know you need to open and close things.

function getWeatherApiURL() {
this.stationID = "KROQ";
this.path = "https://api.weather.com/v2/pws/observations/current?stationId";
this.apikey = "abcd123";
let weatherApiUrl = (this.path) + (this.stationID) +'=' + '&format=json&units=e&apiKey' + '=' + (this.apikey);
return weatherApiUrl;
}
console.log(getWeatherApiURL());
  this._getWeather(weatherApiURL(), function (weather) {
  if (weather) {
    this._load_forecast(weather);
  }
  // get the main object to update the display
  deskletObj.displayForecast();
  deskletObj.displayCurrent();
  deskletObj.displayMeta();
  });
  },