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Retrieving Data - Solution

2:15 with Andrew Chalkley

In this video I'll show you how I retrieved information from a weather API.

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OpenWeatherMap API Solution Code

The OpenWeatherMap API works a little differently than the API shown in the video:

You can't pass it a city/state combination, but you can either pass it a city name or a zip code
You need to specify the units format as an additional query string parameter in order to get the temperature in fahrenheit
- Temperature is available in Fahrenheit, Celsius and Kelvin units
- For temperature in Fahrenheit use units=imperial
- For temperature in Celsius use units=metric
- Temperature in Kelvin is used by default, no need to use units parameter in API call

Here's an overview of the differences from the code shown in the video:

app.js
- Removed the code that replaces spaces with underscores
weather.js
- Switched to using the querystring.stringify() method to URL encode a parameters object
- Added a check to see if the provided query is a number or not in order to determine which API endpoint to use

Here's the code:

`app.js`

const weather = require('./weather');

const query = process.argv.slice(2).join(' ');

//query: 90201
//query: Los Angeles

weather.get(query);

`weather.js`

const https = require('https');
const querystring = require('querystring');
const api = require('./api.json');

// Print out temp details
// Print out error message

function get(query) {
    const parameters = {
      APPID: api.key,
      units: 'imperial'
    };

    const zipCode = parseInt(query);
    if (!isNaN(zipCode)) {
      parameters.zip = zipCode + ',us';
    } else {
      parameters.q = query + ',us';
    }

    const url = `https://api.openweathermap.org/data/2.5/weather?${querystring.stringify(parameters)}`;
    console.log(url);

    const request = https.get(url, response => {
        let body = "";
        // Read the data
        response.on('data', chunk => {
            body += chunk;
        });
        response.on('end', () => {
            console.log(body);
            //Parse data
            //Print the data
        });
    });
}

module.exports.get = get;

//TODO: Handle any errors

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In my app.js file, I included the weather module 0:00

that includes all the functionality to get the weather based on a query. 0:04

The next line of code cleans up the user input to create queries for 0:10

the WeatherUnderground API. 0:13

Maybe other API queries would have plus symbols instead of underscores. 0:18

On the next line, I pass the query into the weather module's get function. 0:23

Let's take a look at the weather code. 0:29

The first line is straightforward. 0:32

I'm including the HTTPS module. 0:34

The second line is something new. 0:37

I'm requiring a json file. 0:39

In Node.js you can require JSON files as well as JavaScript modules. 0:42

Requiring a JSON file can be handy to store configuration you don't want to 0:46

include in your git repository such as an API key or database credentials. 0:51

You don't want other people using your API key and 0:59

attributing their usage of the API to you or your application. 1:02

Then I have some comments to remind me of the things that I need to do like print 1:07

out the temperature details or to print out error messages. 1:12

Then, we have the get function that takes in the query generated from the command 1:17

line arguments. 1:21

The WeatherUnderground API requires you to build your query up like this. 1:23

With the API key, And 1:27

the query in the URL like this. 1:32

Then, I read in the body, and then I log out the body. 1:40

I've also included reminders that I need to parse and 1:48

print out the data once it's parsed. 1:51

Then, I export the get function here. 1:55

Finally, I've added a reminder to add errors later. 1:58

How did my solution differ from yours? 2:02

Your next challenge is to parse the JSON, look for the appropriate keys, and 2:05

print out the temperature message for the city you're querying about. 2:10

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