Mick Redman: functions

Thursday, 2 December 2010

How to set off multiple functions repeatedly using JavaScript

We are going to create an array of functions we'd like to kick off every 5 seconds. In this example I've used alerts, but this could make an excellent poll for changes to a file.

Once our array is created we can call a function which will perform the actions.

First we need to declare our function and stick it in the <head> of our page.
<script>

function runFunctions(funcArr, delay)
{
   setInterval(
   function()
   {
   for(i=0; i<funcArr.length; i++)
   {
   eval(funcArr[i]);
   }
   }, delay);
}

</script>

Now we can call our function from within the page <body> or just as easily in the <head>

<script>
   var myFuncs=new Array("alert('Mick')","alert('Mack')","alert('Paddy')","alert('Whack')");
   runFunctions(myFuncs, 5000);
</script>

Monday, 11 October 2010

jQuery Functions and Toggle

Below are a few examples of how to create functions in jQuery. Th real beauty lies in the fact that you can create your own library of functions in an external file. You should try and make them as flexible as possible.

See demo.

<!DOCTYPE html>
<html lang="en>
<head>
<meta charset="UTF-8">
<title>jQuery Functions</title>
<style type="text/css">
body
{
font-family:Sans-serif;
}
.myToggleClass
{
background:#FF0000;
font-size:2em;
color:#FFFFFF;
}
</style>
<script src="http://www.google.com/jsapi"></script>
<script>
google.load("jquery", "1");
google.load("jqueryui", "1");
</script>
<script>
/* Functions are declared here */
$.fn.firstWithoutParameters = function()
{
alert('Without parameters');
}
$.fn.secondWithParameters = function(param)
{
alert('With parameter of '+param);
}
$.fn.grow = function()
{
return $(this).css('font-size','2em');
}
$.fn.growSlowly = function()
{
return $(this).animate(
{
fontSize:'2em'
}, 1500 );
}
$.fn.doTheToggle = function()
{
return $(this).toggleClass('myToggleClass');
}

/* Functions are called here */
$(document).ready(function()
{
$('#first').click(function()
{
$(this).firstWithoutParameters();
});
$('#second').click(function()
{
$(this).secondWithParameters('Jimmy');
});
$('#third').click(function()
{
$(this).grow();
});
$('#fourth').click(function()
{
$(this).growSlowly();
});
$('#fifth').click(function()
{
$(this).doTheToggle();
});
});
</script>
</head>
<body>
<p id="first">first</p>
<p id="second">second</p>
<p id="third">third</p>
<p id="fourth">fourth</p>
<p id="fifth">fifth</p>
</body>
</html>