CODEWITHSUNDEEP
javascriptjsoneval
XCeptable
XCeptable

Reputation: 1267

why JavaScript is not displaying parsed json data?

This is format of JSON data: [{"options":"smart_exp"},{"options":"user_int"},{"options":"blahblah"}] that I receive through getjson from server. I need to append json with user input. I am trying to do it in this way: 1st convert it into javascript object, append it with user input, again convert to json object & send it back to server for database update. I have converted json to javaScript object using eval(). Now not able to manipulate javascript object. If I convert javascript object back to json object, it displays correctly all data that was sent from server. 

 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
 "http://www.w3.org/TR/html4/strict.dtd">
 <html><head></head>
 <body> 
 <form name="index">
 <p><input type = "text" id = "txt" name = "txt"></input></p>
 <p><input type = "button" id = "send" name = "send" value = "send" 
 onClick="ADDLISTITEM();"></input></p>
 <select name="user_spec" id="user_spec" />
 </form>
 <script>
 function ADDLISTITEM()
 {// this script suffers from errors on eval/JSON.parse methods
 alert (json.length);//outputs corrcet with eval 
 tring = JSON.stringify(json);//outputs corrcet with eval
 alert(jsonString);//outputs corrcet with eval
 alert(json.options[0]);//no output
 }
 </script>
 <script src="http://code.jquery.com/jquery-latest.min.js">    
 </script>
 <script src="http://www.json.org/json2.js"></script>
 <script>
 var json;
 $(document).ready(function() { 
 jQuery .getJSON("http://127.0.0.1/conn_mysql.php", function (jsonData) {
 json = eval(jsonData);
 //json = JSON.parse(jsonData);/*error if uncomment:"IMPORTANT: Remove this line from  
                               json2.js before deployment"*/
 $.each(jsonData, function (i, j) {
 document.index.user_spec.options[i] = new Option(j.options);
 });});
 });
 </script>
 </body>
 </html>

Upvotes: 0

Views: 1572

Answers (3)

Frode
Frode

Reputation: 5710

I don't think the problem here has anything to do with eval/parse etc or the same origin policy. Your json is an array of objects each containing a member named options. Therefore you cannot do json.options[0], you have to do json[0].options.

Upvotes: 0

Fatih Acet
Fatih Acet

Reputation: 29529

var json = [{"options":"smart_exp"}, {"options":"user_int"}, {"options":"blahblah"}]

for (var i = 0; i < json.length; i++){

    alert(json[i].options)

}

Upvotes: 0

AKX
AKX

Reputation: 168913

In jQuery, $.getJSON()'s callback gets called with parsed JSON data; just use it. 

$.getJSON("*.php", function(data) {
   $.each(data, function() { alert(this.options); });
);

should give you an alert for every {"options": "xyzzy"} object in the array.

EDIT after OP edited their post: Your edit clarifies things a little: You won't get any data back -- and it will be completely silent, too, as I found out -- if you violate the same origin policy.

Basically (with exceptions (preflight checks, etc)), you can only access URLs on the exact same domain via AJAX. If your HTML file is a static file served locally, it can not access http://127.0.0.1/; if your file is http://foo.baz.quux.org/, you can't simply AJAX into http://mordor.baz.quux.org .

Upvotes: 3

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