Passing a variable from php to ajax - weird, nothing works - php

Question

I am having great difficulty passing a variable from a PHP file to .js files
The code in the PHP file I used is this:
<script>
jQuery(document).ready(function(){
var uid = <?php echo (intval($uid)); ?>;
//var uid = <?php echo(intval($_SESSION['uid'])); ?>.val();
});
</script>
The variable value should be passed into the .js file to refresh just a certain div on the page (not the whole page) after a form submission is performed.
This is the .js file and the corresponding code starts at "// refresh the monitor list div":
$(function() {
$(".button").click(function() {
// validate and process form here
$('.error').hide();
var domain = $("input#domain").val();
if (domain == "") {
$("label#domain_error").show();
$("input#domain").focus();
return false;
}
var com_domain = $("input#com_domain").val();
if (com_domain == "") {
$("label#com_domain_error").show();
$("input#com_domain").focus();
return false;
}
var cemail = $("input#cemail").val();
var port = $("select#port").val();
var active = $("input#active").val();
var uid = $("input#uid").val();
var main = $("select#main").val();
var dataString = 'cemail='+ cemail + '&domain=' + domain + '&com_domain=' + com_domain + '&active=' + active + '&main=' + main + '&port=' + port;
//alert (dataString);return false;
$.ajax({
type: "POST",
url: "user_add.php",
data: dataString,
success: function() {
$('#monitor_form').append("<div id='message'></div>");
$('#monitor_form form')[0].reset();
$('#message').html("<img id='checkmark' src='images/tick.png' /><b> Monitor sucessfully added!</b>")
.hide()
.fadeIn(500, function() {
$('#message').append("");
});
setTimeout("$('#message').hide().remove();", 6000);
var dataString2 = 'ajax=1&uid=' + uid;
$.ajax({
type: "GET",
url: "monpanel.php",
data: dataString2,
success: function(html_data){
$('#list_monitors').html(html_data);
}
});
//document.onkeydown = showDown;
}
});
return false;
});
});
function showDown(evt) {
event = (evt)? evt : ((event)? event : null);
if (evt) {
if (event.keyCode == 8 && (event.srcElement.type!= "text" && event.srcElement.type!= "textarea" && event.srcElement.type!= "password")) {
// When backspace is pressed but not in form element
cancelKey(evt);
}
else if (event.keyCode == 116) {
// When F5 is pressed
cancelKey(evt);
}
else if (event.keyCode == 122) {
// When F11 is pressed
cancelKey(evt);
}
else if (event.ctrlKey && (event.keyCode == 78 || event.keyCode == 82)) {
// When ctrl is pressed with R or N
cancelKey(evt);
}
else if (event.altKey && event.keyCode==37 ) {
// stop Alt left cursor
return false;
}
}
}
function cancelKey(evt) {
if (evt.preventDefault) {
evt.preventDefault();
return false;
}
else {
evt.keyCode = 0;
evt.returnValue = false;
}
}
/*function mycallbackfunc(v,m,f) {
if (v == 'Cancel') {
$.prompt('The action was ' + v + 'ed');
}
else {
$.prompt('Monitor ' + v + 'd successfully');
}
}*/
// ask for validation on monitor delete, pause, resume request
$(document).ready(function(){
$(".error").hide();
alert("Stage 0! -> uid="+uid.toString());
$("#mondelpau").validate({
debug: false,
rules: {
act: "required",
uid: "required",
sid: "required"
},
/*messages: {
name: "Please let us know who you are.",
email: "A valid email will help us get in touch with you.",
},*/
submitHandler: function(form) {
// do other stuff for a valid form
//$.post('delpaures.php', $("#mondelpau").serialize(),
alert("Stage 1! -> uid="+uid.toString());
$.ajax({
async: false,
type: "POST",
url: "delpaures.php",
data: $("#mondelpau").serialize(),
success: function(data) {
$('#monadiv').html(data);
//$('#results').html(data);
//alert (data);return false;
// refresh the monitor list div
//$('#list_monitors').load(dataString8);
//var uid = $("input#uid").val();
//var dataString8 = 'ajax=1&uid=' + $("input#uid").val();
var dataString8 = 'ajax=1&uid=' + uid; // .val()
//var dataString8 = 'ajax=1&uid=19';
alert("Stage 2! -> uid="+uid.toString());
$.ajax({
async: false,
type: "GET",
dataType: "html",
url: "monpanel.php",
data: dataString8,
success: function(html_data){
alert("Stage 3!");
$("#list_monitors").css("background-color","#FF0000");
$("#list_monitors").html(html_data);
}
});
}
});
}
});
});
Needless to say I have tried everything, even renaming .js file to .php and redirecting to them with .htaccess, but that doesn't work either.

Answer 1

The reason you cannot access the variable in your js file is that the variable 'uid' is defined in a different scope than the js file. Its the same thing as:
if(true) {
var a = 1;
}
if(true) {
// b will be undefined since 'a' was defined in another scope
var b = a;
}
// so
jQuery(document).ready(function({
// this is one scope
var a = 1;
});
jQuery(document).ready(function({
// this is another scope and b will be undefined
var b = a;
});
You need to store the uid in a hidden field like:
<intput type="hidden" id="hidUid" value="<?php echo (intval($uid)); ?>"/>
And then inside the scope of your javascript ($(document).ready)
var uid = $("#hidUid").val();