Question

Hello guys that is not normal 🙂 !!

foo.php

     <?php 
         if (isset($_POST['data']))
         $stringData = $_POST['data'];
         $file = "ciao.txt"; 
         $fh = fopen($file, 'w') or die("can't open file");
         fwrite($fh, $stringData);
         fclose($fh); 

         ?>

file.js

    function WriteToFile() {
        var dataa = "foo bar";
     $.post("foo.php", {data: dataa}, function(result){ alert("ciaoooo!!");}            
           , "json");
    }

this is the error and i can’t write on my file.txt

Notice: Undefined variable: stringData

I tried also with that kind of function

function WriteToFile() {
    var data = "foo bar";
$.ajax({
    url: 'foo.php',
    type: 'POST',
    data: { 'data' : 'data'},
    success: function() {
        alert('the data was successfully sent to the server');
    }
});

but the result is the same!! Anyone have some idea???

Answer 1

Ok, I think here’s what is happening:

The code you have posted (foo.php/file.js in example 1) is correct, and will work without issues. I am not sure if you are trying to hit the foo.php URL directly in the browser. In that case there is nothing posted, so $stringData will be undefined, and it will throw the notice you are seeing.

What you need to do is:
1. Include the file.js script in an HTML file.
2. Make sure you have included jquery library
3. Make sure that the PHP (foo.php) file path is correct in $.POST
4. Call WriteToFile() on the HTML body onLoad function

Here is a sample HTML which should work (update path to foo.php if needed)

<script src ="http://ajax.googleapis.com/ajax/libs/jquery/1.7/jquery.min.js"></script>
<script>
function WriteToFile() 
{
    var dataa = "foo bar";
    $.post("foo.php", {data: dataa}, function(result){ alert("ciaoooo!!");}, "json");
}
</script>