Jquery ajax call from javascript to PHP

Question

There seems to be a problem with the code I have for calling php from javascript with jquery ajax. The ajax call seems to be successful but I don\'t get the correct informa

Answer 1

I found the answer! Thanks to all of you who had suggestions about the SQL call. But here is the actual answer to my question.

There are four steps in making an ajax Javascript to PHP call. The first two steps happen in the Javascript. The other two steps happen in the PHP.

Step 1. In Javascript decide what variables are needed in the PHP function, retrieve them.

Step 2. Make the ajax call to the PHP function. jquery has a convenient way of passing values to PHP. You have a an array of name-value pairs like this in the data item for the ajax call.

 data: { node: selectnod, option: "delete" },

Step 3. Have your PHP function ready in a PHP file. Write the function like this.

function updatetree($node, $option) {

Step 4. Echo a call to the php function within that PHP file.

With these four steps you should have a succesful call to PHP and be able to return information to javascript from the PHP function.

Here is the javascript function.

function deleteitem()
{

     //Get selected node to send to PHP function
     var selectnod = getCookie('pnodid'); 

     //Define php info, specify name of PHP file NOT PHP function
     //Note that by loading the PHP file you will probably execute any code in that file
     //that does not require a function call
     //Send PHP variables in the data item, and make ajax call
     //On success perform any action that you want, such as load a div here called thenode
     $.ajax({
         url: "uptree.php",
         type: "POST",
         data: { node: selectnod, option: "delete" },
         cache: false,
         success: function (response) {
             $('#thenode').html(response);
         }
     });

}

Here is the PHP file uptree.PHP. It has a function defined, called updatetree. It also has an echo statement to call that function. This just seems to be the way to cause the function to run. Ajax itself doesn't call the function.

So to recap. Javascript gets variables, makes ajax call to PHP file. Ajax loads PHP file which contains echo statement that causes PHP function to run. That PHP function is defined in that same file. The function return statement sends information back to javascript through ajax. Javascript does something with that information, e.g. load it into a div on the HTML page.