Tutorial4

# Tutorial 4: jQuery javascript framework

## Short Introducation

jQuery is a fast, concise, JavaScript Library that simplifies how you traverse HTML documents, handle events, perform animations, and add Ajax interactions to your web pages.

There are a lot of javascript frameworks: prototype, mootool, dojo, YUI etc. Yet why we pick up jquery is just a matter of taste. (Dude, I can't tell more, that's just personal feeling.)

## Used in Foorum

We load jquery in every page by default.

- disable Submit button when submit() form to avoid duplicate submit.

        $(document.forms).each( function(theform) {

            // disabled the Submit and Reset when submit a form
            // to avoid duplicate submit
            $(theform).submit( function() {
                $('input:submit').attr( { disabled : 'disabled' } );
                $('input:reset').attr(  { disabled : 'disabled' } );
            } );

            // Press Ctrl+Enter to submit the form. like QQ.
            $(theform).keypress( function(evt) {
                var x = evt.keyCode;
                var q = evt.ctrlKey;

                if (q && (x == 13 || x == 10)) {
                    theform.submit();
                }
            } );
        } );

- timezone auto-detection. 2008-01-17 15:46:33 in my local time, meanwhile that's 2008-01-17 16:46:33 in your computer. that's provided by this piece of code. (put class="date" in MySQL DateTime format span. <span class="date">2008-01-17 15:46:33</span>)

        // follows are copied from datePicker/date.js
        // utility method
        var _zeroPad = function(num) {
            var s = '0'+num;
            return s.substring(s.length-2)
            //return ('0'+num).substring(-2); // doesn't work on IE :(
        };

       $(".date").each(function (i) {
            var s = $(this).text();
            if (! s) { return false; }

            var f = this.id; //format
            if (! f) {
                f = 'yyyy-mm-dd hh:ii:ss';
            }

            var d = new Date(1997, 1, 1, 1, 1, 1);
            var iY = f.indexOf('yyyy');
            if (iY > -1) {
                d.setFullYear(Number(s.substr(iY, 4)));
            }
            var iM = f.indexOf('mm');
            if (iM > -1) {
                d.setMonth(Number(s.substr(iM, 2)) - 1);
            }
            d.setDate(Number(s.substr(f.indexOf('dd'), 2)));
            d.setHours(Number(s.substr(f.indexOf('hh'), 2)));
            d.setMinutes(Number(s.substr(f.indexOf('ii'), 2)));
            d.setSeconds(Number(s.substr(f.indexOf('ss'), 2)));

            var timezoneOffset = -(new Date().getTimezoneOffset());
            d.setMinutes(d.getMinutes() + timezoneOffset);

            if (! isNaN(d.getFullYear()) && d.getFullYear() > 1997) {
                var t = f
                    .split('yyyy').join(d.getFullYear())
                    .split('mm').join(_zeroPad(d.getMonth()+1))
                    .split('dd').join(_zeroPad(d.getDate()))
                    .split('hh').join(_zeroPad(d.getHours()))
                    .split('ii').join(_zeroPad(d.getMinutes()))
                    .split('ss').join(_zeroPad(d.getSeconds()))
                    ;

                $(this).text(t);
            }
       } );

Above code is from http://foorum.googlecode.com/svn/trunk/root/static/js/utils.js it may be changed later.

## jQuery UI

http://ui.jquery.com/

We are using Tabs. http://dev.jquery.com/view/tags/ui/1.0.1a/demos/ui.tabs.html

# SEE ALSO

Tutorial1, Tutorial2, Tutorial3, Tutorial5

# WHERE TO GO NEXT

- Get the lastest version from http://code.google.com/p/foorum/wiki/Tutorial4
- Index Page