Some Useful JavaScript & jQuery Snippets – Part 2

Check if cookies are enabled $(document).ready(function() { var dt = new Date(); dt.setSeconds(dt.getSeconds() + 60); document.cookie = "cookietest=1; expires=" + dt.toGMTString(); var cookiesEnabled = document.cookie.indexOf("cookietest=") != -1; if(!cookiesEnabled){ //cookies are not enabled } }); Toggle all checkboxes var tog = false; // or true if they are checked on load $('a').click(function() { $("input[type=checkbox]").attr("checked",!tog); tog = […]

snippets_part2

  • Check if cookies are enabled
  • $(document).ready(function() {
        var dt = new Date();
        dt.setSeconds(dt.getSeconds() + 60);
        document.cookie = "cookietest=1; expires=" + dt.toGMTString();
        var cookiesEnabled = document.cookie.indexOf("cookietest=") != -1;
        if(!cookiesEnabled){
            //cookies are not enabled
        }
    });
  • Toggle all checkboxes
  • var tog = false; // or true if they are checked on load
    $('a').click(function() {
        $("input[type=checkbox]").attr("checked",!tog);
        tog = !tog;
    });
  • Get the index of an element
  • $("ul > li").click(function () {
        var index = $(this).prevAll().length;
    });
  • Validate date of birth
  • $("#lda-form").submit(function(){
        var day = $("#day").val();
        var month = $("#month").val();
        var year = $("#year").val();
        var age = 18;
        var mydate = new Date();
        mydate.setFullYear(year, month-1, day);
    
        var currdate = new Date();
        currdate.setFullYear(currdate.getFullYear() - age);
        if ((currdate - mydate) < 0){
            alert("Sorry, only persons over the age of " + age + " may enter this site");
            return false;
        }
        return true;
    });
  • Test if an element is visible
  • if($(element).is(":visible")) {
        //The element is Visible
    }
  • Counting child elements
  • <div id="foo">
    <div id="bar"></div>
    <div id="baz">
    <div id="biz">
    </div>
    <span><span>
    </div>
    
    //jQuery code to count child elements
    $("#foo > div").length
  • Center an element on the screen
  • jQuery.fn.center = function () {
        this.css("position","absolute");
        this.css("top", ( $(window).height() - this.height() ) / 2+$(window).scrollTop() + "px");
        this.css("left", ( $(window).width() - this.width() ) / 2+$(window).scrollLeft() + "px");
        return this;
    }
    
    //Use the above function as:
    $(element).center();
  • Moving options from list A to list B
  • $().ready(function() {
        $('#add').click(function() {
            !$('#select1 option:selected').appendTo('#select2');
        });
        $('#remove').click(function() {
            !$('#select2 option:selected').appendTo('#select1');
        });
    });
  • Select all checkboxes
  • $(document).ready(function(){
        $("#checkboxall").change(function(){
            var checked_status = this.checked;
            $("input[name=checkall]").attr("checked", checked_status);
        });
    
    });
  • Get the current URL
  • $(document).ready(function() {
        var pathname = window.location.pathname;
    });
  • Check if and which key was pressed
  • $(function() {
        $(document).keypress(function(e){
            switch(e.which){
            // "ENTER"
            case 13:
            alert('enter pressed');
            break;
    
            // "s"
            case 115:
            alert('s pressed');
            break;
    
            (...)
    
            }
        });
    
    });

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    Cody loves jQuery - he puts the magic into every web application. He is crazy about Curry dishes.

    View all contributions by

    Website: http://tympanus.net/codrops/author/cody/

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    Feedback 28

    Comments are closed.
    1. 2

      Just a sidenote – with the upcoming 1.4 jQuery (due 14th of January) getting the index will be easier: $(“ul > li”).index();

    2. 3

      if($(element).is(“:visible”)) {
      this doesn’t take visibility of element’s parents into account. something like this might lead to the expected behaviour:
      if($(element).is(“:visible”) && $(element).parents().not(‘:visible’).length == 0) {…

    3. 6

      Cody great share. this will work perfectly with a few projects I’m working on

    Comments are closed.