Question

I have the following PHP code that returns a JSON object via Ajax to the client.

function loadAll(){
    $knowledgeHandler = new KnowledgeLevelHandler();
    $json = $knowledgeHandler->loadAll();        
    header('Content-type: application/json');
    print $json;
}

I have a test function assigned to the success callback of jQuery Ajax.

successCallback = function(data){
    alert("A");
}

options = {    
    "data": data,
    "async": false,
    "type": "post",
    "success":successCallback        
}
$.ajax(url, options);

When I remove the header('Content-type: text/json'); from PHP code, the callback is executed, but when it is executed, the success callback isn’t executed. What is wrong?

Answer 1

I believe you need to specify the returned data type as JSON in your JQuery AJAX call.

http://api.jquery.com/jQuery.ajax/

The json type parses the fetched data file as a JavaScript object and
returns the constructed object as the result data.

successCallback = function(data){
    alert("A");
}

options = {    
    data: data,
    async: false,
    type: "POST",
    success: "successCallback",
    dataType: "json"
}

$.ajax(url, options);

Your successCallback function will now contain a data object, through which you can access your variables; data.var_1, data.some_other_var, etc.

Neal