如何使用PHP从iTunes Search API JSON页面中提取值？

Question

I am creating a website which is going to require up-to-date iPhone App prices, such as on appshopper, and thanks to gbc here on stackoverflow I was directed towards using the iTunes Search API. I am somewhat familiar with PHP though I don't practice it that often and am not familiar with the use of JSON or how to extract values from it. I tried to use the tutorial here: http://webhole.net/2009/11/28/how-to-read-json-with-javascript/ to get it to work, though I had no luck, no data was pulled and I am not skilled enough to figure it out. I have also attempted numerous other tutorials, though the one above seemed to fit the closest to what I needed. This is going to be a necessary portion of the site, though it is not the key component of the site, so it doesn't need to be very robust, it just needs to work. I would appreciate any help, suggestions, or links.

Here is the code that I tried to use, I'm not sure if this is incapable of doing what I want it to or if I made some small error that I'm not sure of because I just followed a tutorial and don't know what I am doing.

<input type="text" id="query" /><button>search</button><br />
<div id="results">

</div>

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function(){
var url='http://ax.itunes.apple.com/WebObjects/MZStoreServices.woa/wa/wsLookup?id=';
var query;
 $('button').click(function(){
  query=$("#query").val();
  $.getJSON(url+query,function(json){
   $.each(json.results,function(i,app){
      $("#results").append('<p>'+app.trackName+'</p>');
   });
  });
 });
});
</script>

Thank you, I really appreciate any help that anyone can provide.

Answer 1

This should get you started.

/wsLookup.php (Server 'proxy' to Apple API)

<?php
// the id for the Yelp app
$id = "284910350";
if (isset($_GET["id"])) {
    // Get the id from the ajax call
    $id = $_GET["id"];
}
// add the id to the url
$apiUrl = "http://ax.itunes.apple.com/WebObjects/MZStoreServices.woa/wa/wsLookup?id=".$id;

// setup the cURL call
$c = curl_init();
curl_setopt($c, CURLOPT_URL, $apiUrl);
curl_setopt($c, CURLOPT_HEADER, false);

// make the call
$content = curl_exec($c);
curl_close($c);
?>

/index.html (Client code that will access the Apple API through the 'proxy')

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
    $(document).ready(function() {
        var url = 'http://www.bgsisson.com/wsLookup.php';
        $('button').click(function() {
            query = $("#query").val();

            $.getJSON(url, {id:query}, function(json) {

                alert("price: " + json.results[0].price);
                alert("description: " + json.results[0].description);
                alert("artistName: " + json.results[0].artistName);

                // use html console to inspect the rest of this object
                console.log(json);
            });
        });
    });
</script>
<input type="text" id="query"/>
<button>search</button>
<br/>

<div id="results"></div>

I have this code hosted on http://www.bgsisson.com/test.html if you want to look at it. Here is the id for the Yelp app, 284910350.