Preventing to execute a JavaScript function more than once - php

Question

I am using JavaScript, jQuery and PHP. How do I limit the JavaScript function to execute once?
My MainJQuery file has Ajax. display.php execute for a while:
....
$.ajax({
type:'POST',
url: 'display.php',
data:'id='+id ,
success: function(data){
$("#response").html(data);
//Here Get_list should be execute only once.
get_list('get');
// Display should execute as usual
display();
}//success
}); //Ajax
.......
get.Php file writes a value to JavaScript:
<?php
print "<script language='javascript'>";
print " g_cost[g_cost.length]=new Array('STA-VES','East',4500);";
print " g_cost[g_cost.length]=new Array('STA-CRF','West',5400);";
print "</script>";
?>
My JavaScript function has the following value from PHP:
function get_list('get'){
for(var i=0;i<g_cost.length;i++)
var temp = g_cost[i];
var Name = temp[0];
var direction = temp[1];
var cost = temp[2];
..
some code
...
}
function display(){
for(var i=0;i<g_cost.length;i++)
alert(g_cost.length);
var temp = g_cost[i];
alert(temp[0]);
alert(temp[1]);
alert(temp[2]);
}
Is it possible to limit to execute a JavaScript function in the jQuery Ajax success portion?

Answer 1

In jQuery you can use the .one() function to bind a method that will execute only once. For example,
$("#someAnchorId").one("click", function(){
//Ajax method here
});
See jQuery one help topic.

Answer 2

You can replace the function with an empty function - this is essentially the same as Rene Saarsoo' solution, but looks nicer:
var get_list = function(param1, param2, ...) {
// your code here
get_list = function() {};
};

Answer 3

Three options:
Set a boolean flag in global scope, set it after a successful run, and check it before running
After a successful run, disable the button (or whatever control you are using to call the one-time method)
Slightly less preferred, but you can also do the validation on server side, i.e. call the method each time, but validate on server-side. The up side is that this will ensure data consistency on the server.

Answer 4

To create a function that executes only once:
get_list = (function(){
var counter = 0;
return function(param1, param2, ...) {
if (counter > 0) {
return;
}
counter++;
// your normal function code here
};
})();
This is almost the same as using a global variable for tracking how many times function is executed, except that instead of a global variable we create a variable, that only the inner function can see. After that you use it get_list as any other function.
This could probably be refactored into something more general in function prototye, so it could be used like this:
get_list = (function (param1, param2, ...) {
...
}).once();

Answer 5

Fastest way is to add one extra line to success declaration:
$.ajax({
type:'POST',
url: 'display.php',
data:'id='+id ,
success: function(data){
if(!arguments.callee.stop){ arguments.callee.stop = true; }else{ return; }
$("#response").html(data);
//Here Get_list should be execute only once
get_list('get');
// display should execute as usual
display();
}//success
}); //ajax

Answer 6

Try disabling the Ajax trigger (link, button, etc.) after a successful call.
Example of a trigger:
<a id="ajax_trigger" href="#" onclick="yourAjaxCall(); return false;">Get List</a>
...
success: function(data){
$("#response").html(data);
//Here Get_list should be execute only once
get_list('get');
// Some code to disable, or hide #ajax_trigger
// in other words, make it unclickable or disappear.
$("#ajax_trigger").css('display': 'none'); // IIRC
// Display should execute as usual
display();
}//success