使用JavaScript和GET请求从api网址提取JSON数据的最佳方法是什么？

Question

I've hit a wall trying to figure out how to send a request to the BandsInTown API and be able to extract a few elements (datetime and venue latitude and longitude) from the returned JSON page that contains music event information. I'm pretty new to JavaScript and web development so any help is much appreciated! The URL I'm using as a request is: http://api.bandsintown.com/artists/Hippo%20Campus/events.json?lapi_version=2.0&app_id=music_matcher

where I will implement flexibility to change the artist called.

I'm not sure if I should add the 'callback= something ' param in the url or not also. I've looked into the 'requests' library through Node.js but I'm not totally sure how to get Node.js and npm to work through Eclipse Neon (the IDE I'm using) so I was really trying to just keep it straightforward and find a pure javascript solution that I could implement directly into my script in Eclipse. I just don't quite understand how to extract the JSON and call it later in my script as results[0].venue.latitude (in order to return latitude of venue) or whatever the 'results' object would be called (this is also part of my issue). Do I even need to put this information into an object?

Answer 1

I ended up using JSON.parse() in addition to an async HTTP request like this:

function httpGetAsync(theUrl, callback) { //theURL or a path to file
var httpRequest = new XMLHttpRequest();
httpRequest.onreadystatechange = function() {
    if (httpRequest.readyState == 4 && httpRequest.status == 200) {
        var data = JSON.parse(httpRequest.responseText);
        if (callback) {
            callback(data);
        }                   
    }
};

httpRequest.open('GET', theUrl, true); 
httpRequest.send(null);
}

and calling it:

httpGetAsync(url, function(data) {
document.write(data[0].venue.latitude);
document.write(data[0].venue.longitude);
document.write(data[0].datetime);
});

However, this method only allows me to make one clean call to the api. When I try to make multiple calls using a loop that calls the function with different urls, my script seems to terminate after the first one. So this is still an issue for my application of this.