Question

this is probably something very simple to fix. Im posting to a php page that returns the ID of the new element created in the db- (posting via $.ajax)- i have logged the returned value.

The following code is the code i use to post

$.ajax({
               type: "POST",
               url: "<?=base_url()?>events/add_tag_js/",
               data: url,
               success: function(html){

                   $("#tag_list").append('<li><span id="" class="tag">'+formvalue+'<span class="remove_tag"><a class="remove_tag_link" href="#">x</a></span></span></li>');
                   $("#add_tag").val('');
                   console.log(html);
               },
               failure: function(){
                    $('.error').show();
                    $("#add_tag").val('');
               }

            });

The return value from the console.log is

{"error":false,"msg":"Tag added","id":44}

but when i do alert(html.id) i get undefined? do i need to parse the json returned to do this? or is my json incorrect?

Answer 1

Maybe you didn’t set the proper content type on your server side script, so jQuery doesn’t know that this is JSON. So either set the content type to application/json on your server script or you could also indicate that you expect JSON in the request using the dataType parameter:

...
type: "POST",
url: "<?=base_url()?>events/add_tag_js/",
data: url,    
dataType: 'json', // indicate that you expect JSON from the server
...

Although it is recommended to have your server side script set the proper content type.