jQuery Cookbook - Cdn.oreilly.com - O'Reilly

Solution
(function($) {
$.fn.myPlugin = function(settings) {
return this.each(function() {
settings = $.extend({ onShow: null }, settings);
$(this).show();
if ( $.isFunction( settings.onShow ) ) {
settings.onShow.call(this);
}
});
};
$(document).ready(function() {
$('div').myPlugin({
onShow: function() {
alert('My callback!');
}
});
});
})(jQuery);
Discussion
While the JavaScript language provides the typeof operator, inconsistent results and
edge cases across web browsers need to be taken into account. jQuery provides
the .isFunction() method to ease the developer’s job. Worth pointing out is that since
version 1.3, this method works for user-defined functions and returns inconsistent results
with built-in language functions such as this:
jQuery.isFunction( document.getElementById );
which returns false in versions of Internet Explorer.
4.8 Removing Whitespace from Strings or Form Values with
jQuery.trim
Problem
You have an input form and need to remove the whitespace that a user may have entered
at either the beginning or end of a string.
Solution
(function($) {
$(document).ready(function() {
$('input.cleanup').blur(function() {
var value = $.trim( $(this).val() );
$(this).val( value );
4.8 Removing Whitespace from Strings or Form Values with jQuery.trim | 83