React-native IOS: Network request failed

Ok thanks to @while1's answer above, I found the answer that worked for me.

The code in my question above is fine. I had to change the info.plist file.

Wow what a pain in the ass apple are, why would they complicate things so extremely?

I basically added the following to the info.plist file.

<key>NSAllowsArbitraryLoads</key>
<true/> 

Like this:

<key>NSAppTransportSecurity</key>
    <dict>
        <key>NSAllowsArbitraryLoads</key>
        <true/>
        <key>NSExceptionDomains</key>
        <dict>
            <key>localhost</key>
            <dict>
                <key>NSTemporaryExceptionAllowsInsecureHTTPLoads</key>
                <true/>
            </dict>
        </dict>
    </dict>

See more info on this in the link in @while1's answer above.

You will need to change your NSAppTransportSecurity policy in info.plist. By default in ios 8 and greater plaintext request are blocked. See Transport security has blocked a cleartext HTTP

your code looks familiar to me seems you're learning Build apps with react native course offered by Stephen Grider.

Even i had this issue.

include delete GLOBAL.XMLHttpRequest; at the beginning of api.js file.

Like this:

delete GLOBAL.XMLHttpRequest;
var _ = require('lodash');
var rootUrl = 'http://api.openweathermap.org/data/2.5/weather?APPID=xxxxxxxxxxxxxxxxxxxxxx';