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Improve my Jquery code to hide and show elements

I am new to Jquery and learning. I wrote some script, but I know its not efficient. Trying to follow DRY principles. Can someone please make this look nicer...it works fine, but i dont like it.
It works, just not efficient code.
<script>
$(document).ready(function () {
var val = $('#id_ocftype').val();
if (val <= 3) {
$('#div_id_date').hide();
$('#div_id_amount').hide();
$('#div_id_signedby').hide();
}
else {
$('#div_id_date').show();
$('#div_id_amount').show();
$('#div_id_signedby').show();
};
$('#id_ocftype').change(function () {
var val = $(this).val();
if (val <= 3) {
$('#div_id_date').hide();
$('#div_id_amount').hide();
$('#div_id_signedby').hide();
}
else {
$('#div_id_date').show();
$('#div_id_amount').show();
$('#div_id_signedby').show();
};
});
});
</script>

Since the conditional statement inside the jquery code is same. You can wrap it into single javascript function and call it whereever it is needed.
<script>
$(document).ready(function () {
const showAndHide = (val) => {
if (val <= 3) {
$('#div_id_date').hide();
$('#div_id_amount').hide();
$('#div_id_signedby').hide();
}
else {
$('#div_id_date').show();
$('#div_id_amount').show();
$('#div_id_signedby').show();
};
}
var val = $('#id_ocftype').val();
showAndHide(val);
$('#id_ocftype').change(function () {
var val = $(this).val();
showAndHide(val);
});
});
</script>

The elements to show or hide are always the same, so you can put them all into a single variable and reference that variable.
$(document).ready(function () {
const elms = $('#div_id_date, #div_id_amount, #div_id_signedby');
const onChange = () => {
const val = $('#id_ocftype').val();
if (val <= 3) {
elms.hide();
} else {
elms.show();
};
};
onChange();
$('#id_ocftype').change(onChange);
});

You can look into .toggleClass.
It allows you to specify when to add/ remove class.
function handleVisibility() {
var val = $('#id_ocftype').val();
const hide = val <= 3
$('#div_id_date').toggleClass('hide', hide)
$('#div_id_amount').toggleClass('hide', hide)
$('#div_id_signedby').toggleClass('hide', hide)
}
$(document).ready(function() {
$('#id_ocftype').change(handleVivibility);
handleVisibility()
});

you can create a common function
<script>
$(document).ready(function () {
var val = $('#id_ocftype').val();
const hideEl = () => {
$('#div_id_date').hide();
$('#div_id_amount').hide();
$('#div_id_signedby').hide();
}
const showEl = () => {
$('#div_id_date').show();
$('#div_id_amount').show();
$('#div_id_signedby').show();
}
if (val <= 3) {
hideEl();
}
else {
showEl();
};
$('#id_ocftype').change(function () {
var val = $(this).val();
if (val <= 3) {
hideEl();
}
else {
showEl();
};
});
});
</script>
also you can use toggle
$("button").click(() => {
$("#test").toggle();
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="test">test</div>
<button>Hide/Show</button>

Is there a way to make "onkeydown" return slower

I want to increment an integer by holding down the right arrow key. The function i made works, but it returns too fast.
document.onkeydown = function (e) {
e = e || window.event;
if (e.keyCode == '39') {
var steps = localStorage.getItem("steps");
if (+steps < 9) {
if (+steps === +steps) {
localStorage.setItem("steps", +steps + +1)
}
} else {
localStorage.setItem("steps", +steps - +10);
}
var sss = localStorage.getItem("steps");
unicorn.className = "unicorn_" + sss + "";
return false;
}
}
The code above is where i'm at now. I am using localStorage to check the stored integer, and incrementing if it matches. Once the integer gets to 9, it substracts back to 0.
can anyone see what i'm doing wrong, or not doing right?

You can also manually keep track of the time using a closure:
document.onkeydown = (function () {
var T0 = Date.now();
return function (event) {
if (Date.now() - T0 > 500) {
console.log("doing my thing over here", Math.random());
T0 = Date.now();
}
}
})();

If you don't want it to execute too fast then consider placing it in a setTimeout
var notTooFast = false;
var timeout = 1000; // change it whatever you want to be
document.onkeydown = function (e) {
e = e || window.event;
if (e.keyCode == '39') {
if (!notTooFast)
{
var steps = localStorage.getItem("steps");
if (+steps < 9) {
if (+steps === +steps) {
localStorage.setItem("steps", +steps + +1)
}
} else {
localStorage.setItem("steps", +steps - +10);
}
var sss = localStorage.getItem("steps");
unicorn.className = "unicorn_" + sss + "";
notTooFast = true;
setTimeout(function () {
notTooFast = false;
}, timeout);
return false;
}
}
}

Uncaught TypeError: Cannot read property 'contains' of null

I'm currently working on a project, where I'm using the following slider in the overal site:
S3Slider
For the particular page I'm currently working on I'm also making use of Walter Zorns' Drag&Drop image library. (Link Here)
Now when I start to make use of the SET_DHTML function, which is required for using the D&D library, my slider starts throwing errors:
Uncaught TypeError: Cannot read property 'contains' of null
The line number given, sends me to the following line:
if($(itemsSpan[currNo]).css('bottom') == 0) {
Which lies in the following piece of code:
s3Slider = function(id, vars) {
var element = this;
var timeOut = (vars.timeOut != undefined) ? vars.timeOut : 2000;
var current = null;
var timeOutFn = null;
var faderStat = true;
var mOver = false;
var items = $("#sliderContent .sliderTopstory");
var itemsSpan = $("#sliderContent .sliderTopstory span");
items.each(function(i) {
$(items[i]).mouseover(function() {
mOver = true;
});
$(items[i]).mouseout(function() {
mOver = false;
fadeElement(true);
});
});
var fadeElement = function(isMouseOut) {
var thisTimeOut = (isMouseOut) ? (timeOut/2) : timeOut;
thisTimeOut = (faderStat) ? 10 : thisTimeOut;
if(items.length > 0) {
timeOutFn = setTimeout(makeSlider, thisTimeOut);
} else {
console.log("Poof..");
}
}
var makeSlider = function() {
current = (current != null) ? current : items[(items.length-1)];
var currNo = jQuery.inArray(current, items) + 1
currNo = (currNo == items.length) ? 0 : (currNo - 1);
var newMargin = $(element).width() * currNo;
if(faderStat == true) {
if(!mOver) {
$(items[currNo]).fadeIn((timeOut/6), function() {
/* This line -> */if($(itemsSpan[currNo]).css('bottom') == 0) {
$(itemsSpan[currNo]).slideUp((timeOut/6), function( ) {
faderStat = false;
current = items[currNo];
if(!mOver) {
fadeElement(false);
}
});
} else {
$(itemsSpan[currNo]).slideDown((timeOut/6), function() {
faderStat = false;
current = items[currNo];
if(!mOver) {
fadeElement(false);
}
});
}
});
}
} else {
if(!mOver) {
if($(itemsSpan[currNo]).css('bottom') == 0) {
$(itemsSpan[currNo]).slideDown((timeOut/6), function() {
$(items[currNo]).fadeOut((timeOut/6), function() {
faderStat = true;
current = items[(currNo+1)];
if(!mOver) {
fadeElement(false);
}
});
});
} else {
$(itemsSpan[currNo]).slideUp((timeOut/6), function() {
$(items[currNo]).fadeOut((timeOut/6), function() {
faderStat = true;
current = items[(currNo+1)];
if(!mOver) {
fadeElement(false);
}
});
});
}
}
}
}
makeSlider();
};
Why is this error being thrown?
Thanks.

I think your problem lies in these two lines:
var currNo = jQuery.inArray(current, items) + 1
currNo = (currNo == items.length) ? 0 : (currNo - 1);
If jQuery doesn't find the item in the array, it's going to send you a value of -1 (on the top line) which will then be changed to 0 because you added 1. Now, if currNo is 0 on the second line, it's going to change it back to -1, which will return you undefined. Maybe try and change it to do this instead:
var currNo = jQuery.inArray(current, items);
if (currNo === items.length - 1) {
currNo = 0;
}
I'm not positive this is the problem, but I can see this becoming an issue if it's not the problem you're currently having.

Implementing Column resize using jQuery

I am trying to implement column resizing using jQuery like below(Please see http://jsbin.com/uduNUbo/1/edit)
Here is my JS code
function resizeEvents(selector) {
function XY(e, ele) {
var parentOffset = ele.parent().offset();
return e.pageX - parentOffset.left;
}
var checkPos;
$(selector).on('mousedown', function () {
$(this).attr('init', true);
return false;
});
$(selector).on('mouseup', function () {
$(this).attr('init', false);
});
$(selector).closest('div').on('mousemove', function (e) {
var inits = $(this).find('.resize').filter(function(){
return $(this).attr('init') == true;
});
if (inits.length > 0) {
var pos = XY(e, inits.first());
if (!checkPos) {
checkPos = pos;
return false;
} else {
var moved = checkPos - pos, a = moved > 0 ? 1 : -1 ;
th.prevAll().each(function () {
if (!$(this).hasClass('.resize')) {
$(this).width($(this).width() + a);
}
});
th.nextAll().each(function () {
if (!$(this).hasClass('.resize')) {
$(this).width($(this).width() - a);
}
});
}
}
});
}
resizeEvents('.resize');
But this is not working, My Question is Is mousemove is written properly, to define properly on correct element or not.

I fixed the code for you:
function resizeEvents(selector) {
var selected;
$(selector).on('mousedown', function () {
selected = $(this);
return false;
});
$(document).mouseup(function () {
selected = null;
}).mousemove(function(e) {
var target = $(e.target);
var table = target.parents('.table');
if (table.length && selected) {
var x = e.pageX - table.offset().left;
var splitter_x = selected.offset().left;
var prev = selected.prev();
var next = selected.next();
prev.width(prev.width() + (x - splitter_x));
next.width(next.width() - (x - splitter_x));
}
});
}
http://jsbin.com/uduNUbo/5/edit

Javascript's Callback Function

I am using Lazy Load Jquery plugin here on my test page: http://bloghutsbeta.blogspot.com/2012/03/testing-2_04.html
And this is the minified script for lazyload:
Code:
<script src="http://files.cryoffalcon.com/javascript/jquery.lazyload.min.js" type="text/javascript" charset="utf-8"></script>
this one is to trigger lazy load:
Code:
<script type="text/javascript" charset="utf-8">
$(function() {
$("img").lazyload({
effect : "fadeIn"
});
});
</script>
In the above script I have added fadeIn effect to it, I don't know if I have done it right according to script writting I am not good in scripts ^^ So, I would like have an advise if it's well written or there is some comma mistake.
But that is not my important question, all of the above lazy load plugin is used with QuickSand Jquery plugin that I am using for sorting.
QuickSand Jquery Plugin requires callback function if it's tooltip or Lazy Load, So can someone kindly tell me how to make lazy load work together with quicksand jquery.
Here is the quicksand's script:
Code:
<script type="text/javascript">
(function(cash) {
$.fn.sorted = function(customOptions) {
var options = {
reversed: false,
by: function(a) {
return a.text();
}
};
$.extend(options, customOptions);
$data = $(this);
arr = $data.get();
arr.sort(function(a, b) {
var valA = options.by($(a));
var valB = options.by($(b));
if (options.reversed) {
return (valA < valB) ? 1 : (valA > valB) ? -1 : 0;
} else {
return (valA < valB) ? -1 : (valA > valB) ? 1 : 0;
}
});
return $(arr);
};
})(jQuery);
$(function() {
var read_button = function(class_names) {
var r = {
selected: false,
type: 0
};
for (var i=0; i < class_names.length; i++) {
if (class_names[i].indexOf('selected-') == 0) {
r.selected = true;
}
if (class_names[i].indexOf('segment-') == 0) {
r.segment = class_names[i].split('-')[1];
}
};
return r;
};
var determine_sort = function($buttons) {
var $selected = $buttons.parent().filter('[class*="selected-"]');
return $selected.find('a').attr('data-value');
};
var determine_kind = function($buttons) {
var $selected = $buttons.parent().filter('[class*="selected-"]');
return $selected.find('a').attr('data-value');
};
var $preferences = {
duration: 800,
easing: 'easeInOutQuad',
adjustHeight: 'dynamic'
};
var $list = $('#data');
var $data = $list.clone();
var $controls = $('ul#gamecategories ul');
$controls.each(function(i) {
var $control = $(this);
var $buttons = $control.find('a');
$buttons.bind('click', function(e) {
var $button = $(this);
var $button_container = $button.parent();
var button_properties = read_button($button_container.attr('class').split(' '));
var selected = button_properties.selected;
var button_segment = button_properties.segment;
if (!selected) {
$buttons.parent().removeClass('selected-0').removeClass('selected-1').removeClass('selected-2');
$button_container.addClass('selected-' + button_segment);
var sorting_type = determine_sort($controls.eq(1).find('a'));
var sorting_kind = determine_kind($controls.eq(0).find('a'));
if (sorting_kind == 'all') {
var $filtered_data = $data.find('li');
} else {
var $filtered_data = $data.find('li.' + sorting_kind);
}
if (sorting_type == 'size') {
var $sorted_data = $filtered_data.sorted({
by: function(v) {
return parseFloat($(v).find('span').text());
}
});
} else {
var $sorted_data = $filtered_data.sorted({
by: function(v) {
return $(v).find('strong').text().toLowerCase();
}
});
}
$list.quicksand($sorted_data, $preferences, function () { $(this).tooltip (); } );
}
e.preventDefault();
});
});
var high_performance = true;
var $performance_container = $('#performance-toggle');
var $original_html = $performance_container.html();
$performance_container.find('a').live('click', function(e) {
if (high_performance) {
$preferences.useScaling = false;
$performance_container.html('CSS3 scaling turned off. Try the demo again. <a href="#toggle">Reverse</a>.');
high_performance = false;
} else {
$preferences.useScaling = true;
$performance_container.html($original_html);
high_performance = true;
}
e.preventDefault();
});
});
</script>

you can use this:
$list.quicksand($sorted_data, $preferences, function(){
$(this).tooltip ();
$("img").lazyload({
effect : "fadeIn"
});
});