Check when a checkbox has its state changed on Javascript - javascript

I've created some checkboxes dynamically using JavaScript (below), any ideas on how to call a function when a checkbox is clicked (has its state changed)?
var eng_types = table[3].slice(3);
for(var i in eng_types) {
var name = eng_types[i];
// Create the necessary elements
var label = document.createElement("label");
var checkbox = document.createElement("input");
var description = document.createTextNode(name);
checkbox.type = "checkbox"; // Make the element a checkbox
checkbox.value = name; // Make its value "pair"
checkbox.name = i; // Give it a name we can check
label.appendChild(checkbox); // Add the box to the element
label.appendChild(description); // Add the description to the element
// Add the label element to your div
document.getElementById('eng_options').appendChild(label);
}
Any ideas on how to make each checkbox appear on a new line would also be appreciated.
Thanks in advance!

Using jQuery checkbox checked state changed event:
$("#i").change(function() {
if(this.checked) {
//Do stuff
}
});
Since you're adding the elements dynamically, a more robust solution might be to use this (thanks to #IgorAntun for mentioning bind and on):
$(document).on("change", "#i", function() {
if(this.checked) {
//Do stuff
}
});
To add context to the comments: The above examples previously used the selector $("[name='i']"), because I was treating checkbox.name = i like a string, instead of the variable that it was.
With regards to making each checkbox appear on a new line, you could <p></p> tags, <br /> tags, <div></div> tags-- really any tag that groups elements or has spacing. Additionally, you could use CSS. This method is my favorite, because it allows the spacing of the checkboxed to be adjusted, which you can't do with HTML tags.
input {
display: block;
margin-top: 2px;
}

You could also also use .bind('change', [...]) or .on('change', [...]), as an alternative to #IronFlare's answer. Examples:
Using .bind('change'):
$('#item-to-check').bind('change', function() {
if(this.checked) {
// Element is checked
} else {
// Element is not checked
}
});
Using .on('change'):
$('#item-to-check').on('change', function() {
if(this.checked) {
// Element is checked
} else {
// Element is not checked
}
});
Also, I recommend checking out Matt's answer on What is best way to perform jQuery .change().

Related

How to use javascript to get the value of checked checkbox dynamically

I'm new to JavaScript.
I have a webpage that the users can search the document ID and add it to their favourite. after submitting the search criteria, it shows a list ID and a checkbox next to it. so the user can check the checkbox or uncheck it to add and remove them from their list.
My issue is my code can't get the value of the checkbox generated. for example, there are three checkbox generated, chk1,chk2,chk3. when none of them are checked, my code is working I can get the value of the checkbox. but when one of them is checked for example, chk3 is checked, when I check chk1, it still shows the value of chk3 rather than chk1. I want to get the value of that checkbox just checked. I'm struggled to make it right.
<tr><%do until results_rs.EOF%>
<td class="tdid"><%Response.Write results_rs("id")%></td>
<td><input type="checkbox" id="myCheckbox" name ="myf[]" value="<%=results_rs("id")%>" onchange="myfc()">
<script>
function myfc(){
var selchb = getSelectedChbox(this.form);
alert(selchb)
}
function getSelectedChbox(frm) {
var selchbox = null;
var chk_arr=document.getElementsByName("myf[]")
var chklength=chk_arr.length
for (k = 0; k < chklength; k++) {
if (chk_arr[k].checked == true)
selchbox=chk_arr[k].value
}
return selchbox
**strong text**// rs.close;
// connection.close
}
</script></td>
<%results_rs.MoveNext%>
</tr>
The minimal change would be to pass this into myfc:
onchange="myfc(this)"
...and then use that in myfc:
function myfc(cb){
alert(cb.value);
}
But you might look into more modern event handling with addEventListener and such.
Note that there's no need to put an id on the checkbox, and in fact, it's invalid to have more than one checkbox with the same id, so probably best to just remove the id="myCheckbox" part entirely.
IDs in JS must be unique. Use a class class="myCheckbox"
Then you can do
window.addEventListener("load",function() {
var checks = document.querySelectorAll(".myCheckbox");
for (var i=0;i<checks.length;i++) { // all .myCheckbox
checks[i].addEventListener("click",function() {
console.log(this.checked,this.value); // this specific box
var checks = document.querySelectorAll(".myCheckbox:checked");
for (var i=0;i<checks.length;i++) { // all CHECKED .myCheckbox
console.log(checks[i].value); // only checked checkboxes are shown
}
});
}
});
In your case for example
window.addEventListener("load",function() {
var checks = document.querySelectorAll(".myCheckbox");
for (var i=0;i<checks.length;i++) { // all .myCheckbox
checks[i].addEventListener("click",function() {
if (this.checked) myfc(this.value); // this specific box
});
}
});

Recreate Select Control Options Dynamically jQuery

I have the following function which I use to populate a Select control with options. I am grabbing values from objects on the document, and if a condition is met, throwing another value into a Select Control as an option...
function dispatchList() {
//grab list element
var list = document.getElementById("techName");
//foreach div assigned the .square class,
$('.square').each(function () {
//convert each div with .square class toString
var square = $(this).html().toString();
//grab availability value
var availability = $(this).find('tr:eq(4)').find('td').text();
//grab IP
var online = $(this).find('tr:eq(3)').find('td').text()
//if availability and IP values meet below condition...
if ((availability === "True") && (online.indexOf("10.") === 0)) {
//grab the name value from this div
var availableName = $(this).find('tr:eq(0)').find('td').text();
//create a new option element
var item = document.createElement("option");
//create a new text node containing the name of the tech
item.appendChild(document.createTextNode(availableName));
//append the new text node (option) to our select control
list.appendChild(item);
}
})
}
This function works great, but it runs when the document is ready. I need it to run when the document is ready, but also to recreate this list without refreshing the page. Ideally the select control could be emptied and recreated with a click event on a div.
This is the part I have struggled with. I have the following click event which it would make sense to chain this to, but I have not been able to work it out...
function availability() {
//for each element with a class of .square...
$('.square').each(function () {
//grab the id of each input element (button) contained in each .square div...
var btnId = $(this).find("input").attr("id");
//when .square div is clicked, also click it's associated asp button...
$(this).on('click', function (clickEvent) {
document.getElementById(btnId).click();
//****AND ALSO TRIGGER THE dispatchList() FUNCTION TO REBUILD THE #techName LIST****
})
})
}
Can this be done without AJAX or some other post back on the select control?
Does the #techName list need to be emptied first, and then rebuilt?
Thank you for any advice!
$(document).ready(function(){
$(".square").on('click', function (clickEvent) {
var el = clickEvent.target || clickEvent.srcElement
document.getElementById($(el).find('input').attr("id")).click();
dispatchList();
})
})
That's all i can do with the given question. I didn't test the code. You can give fiddle or anything to test. Also this function is written in the browser.

Jquery checkbox affect one item not all items

I was wondering if someone can help me please, I have a series of checkboxes that when clicked change the div background, activate 2 inputs and add a tick icon. My issue is that when one check box is checked the class .TickIco shows for all and so does the .disableToggle
How can i get it so that this only affects one .checkBG at a time and not all of them?
Hopefully this JSFiddle will help explain what I mean.
https://jsfiddle.net/jayjay89/xfg96we5/
thanks
$(".checkBG").click(function () {
var checked = $(this).is(':checked');
var location = $(this).parent().parent().parent();
if (checked) {
$(this).parent().parent().parent().addClass("activeformBlock");
$(".tickIco").show();
$(".disabletoggle").removeAttr("disabled");
} else {
$(this).parent().parent().parent().removeClass("activeformBlock");
$(".tickIco").hide();
$(".disabletoggle").attr('disabled', 'disabled');
}
});
thanks
you can use the context in which the selector will be looked.
You already have the location variable which is the parent context for one of your row
$(".checkBG").click(function () {
var checked = $(this).is(':checked');
var location = $(this).parent().parent().parent();
if (checked) {
$(this,location).parent().parent().parent().addClass("activeformBlock");
$(".tickIco",location).show();
$(".disabletoggle",location).removeAttr("disabled");
} else {
$(this,location).parent().parent().parent().removeClass("activeformBlock");
$(".tickIco",location).hide();
$(".disabletoggle",location).attr('disabled', 'disabled');
}
});
Your issue lies in the way you are selecting the .tickIco and .disabletoggle elements:
$(".tickIco").show();
$(".disabletoggle").removeAttr("disabled");
These jquery calls use selectors that match all classes of .tickIco and .disabletoggle.
Dirty solution (finds elements of the parent with matching classes using .find()):
$(this).parent().parent().parent().find(".tickIco").show();
$(this).parent().parent().parent().find('.disabletoggle').removeAttr("disabled")
Better solution:
jQuery selecter takes the context of your selection as a second argument so you can:
var context = $(this).parent().parent().parent();
$(".tickIco", context).show();
$('.disabletoggle', context).removeAttr("disabled")

Modify function to filter by several data-attributes simultaneously

The function below allows users to filter products by data-attributes, and accommodates filtering by multiple values simultaneously. It does this by creating an array of the values selected, and when any of the values are clicked (in this case checked/unchecked) it hides all the items and then re-shows those that match the values in the updated array.
It works correctly when filtering for one data-attribute, but when combined to filter by more than one attribute it no longer shows all results matching any of the values and instead only shows results matching all the specified values.
I've posted a fiddle which demonstrates the problem here: http://jsfiddle.net/chayacooper/WZpMh/94/ All but one of the items have the values of both data-style="V-Neck" and data-color="Black" and they should therefore remain visible if either of the filters are selected, but if another value from a different data-attribute some of the items are hidden.
$(document).ready(function () {
var selected = [];
$('#attributes-Colors *').click(function () {
var attrColor = $(this).data('color');
var $this = $(this);
if ($this.parent().hasClass("active")) {
$this.parent().removeClass("active");
selected.splice(selected.indexOf(attrColor),1);
}
else {
$this.parent().addClass("active");
selected.push(attrColor);
}
$("#content").find("*").hide();
$.each(selected, function(index,item) {
$('#content').find('[data-color *="' + item + '"]').show();
});
return false;
});
$('#attributes-Silhouettes *').click(function () {
var attrStyle = $(this).data('style');
var $this = $(this);
if ($this.parent().hasClass("active")) {
$this.parent().removeClass("active");
selected.splice(selected.indexOf(attrStyle),1);
}
else {
$this.parent().addClass("active");
selected.push(attrStyle);
}
$("#content").find("*").hide();
$.each(selected, function(index,item) {
$('#content').find('[data-style *="' + item + '"]').show();
});
return false;
});
});
Both of your handlers are updating the selected array, but only one handler executes on a click. The first one if a color was (de)selected, the second if a style. Let's say you've clicked on "Black" and "Crew Neck". At that time your selected array would look like this: [ "Black", "Crew_Neck" ]. The next time you make a selection, let's say you click "Short Sleeves", the second (style) handler executes. Here's what is happening:
Short_Sleeves gets added to the selected array.
All of the items are hidden using $("#content").find("*").hide();
The selected array is iterated and items are shown again based on a dynamic selector.
Number 3 is the problem. In the above example, a style was clicked so the style handler is executing. Any items in the selected array that are colors will fail because, for example, no elements will be found with a selector such as $('#content').find('[data-style *="Black"]').show();.
I would suggest 2 things.
Keep 2 arrays of selections, one for color, one for style.
Combine your code to use only a single handler for both groups.
Here's a (mostly) working example.
Note that I added a data-type="color|style" to your .filterOptions containers to allow for combining to use a single handler and still know which group was changed.
Here's the full script:
$(document).ready(function () {
// use 2 arrays so the combined handler uses correct group
var selected = { color: [], style: [] };
// code was similar enough to combine to 1 handler for both groups
$('.filterOptions').on("click", "a", function (e) {
// figure out which group...
var type = $(e.delegateTarget).data("type");
var $this = $(this);
// ...and the value of the checkbox checked
var attrValue = $this.data(type);
// same as before but using 'type' to access the correct array
if ($this.parent().hasClass("active")) {
$this.parent().removeClass("active");
selected[type].splice(selected[type].indexOf(attrValue),1);
}
else {
$this.parent().addClass("active");
selected[type].push(attrValue);
}
// also showing all again if no more boxes are checked
if (attrValue == 'All' || $(".active", ".filterOptions").length == 0) {
$('#content').find('*').show();
}
else {
// hide 'em all
$("#content").find("*").hide();
// go through both style and color arrays
for (var key in selected) {
// and show any that have been checked
$.each(selected[key], function(index,item) {
$('#content').find('[data-' + key + ' *="' + item + '"]').show();
});
}
}
});
});
UPDATE: incorporating suggestions from comments
To make the handler work with checkboxes instead of links was a small change to the event binding code. It now uses the change method instead of click and listens for :checkbox elements instead of a:
$('.filterOptions').on("change", ":checkbox", function (e) {
// handler code
});
The "All" options "hiccup" was a little harder to fix than I thought it would be. Here's what I ended up with:
// get a jQuery object with all the options the user selected
var checked = $(":checked", ".filterOptions");
// show all of the available options if...
if (checked.length == 0 // ...no boxes are checked
|| // ...or...
checked.filter(".all").length > 0) // ...at least one "All" box is checked...
{
// remainder of code, including else block, unchanged
}
I also added an all class to the appropriate checkbox elements to simplify the above conditional.
Updated Fiddle

How to toggle checkbox selection rather than only selecting?

I currently am using this JavaScript code snippet to select 3 checkboxes at a time
$(document).ready(function() {
var $cbs = $('input:checkbox[name="select[]"]'),
$links = $('a[name="check"]');
$links.click(function() {
var start = $links.index(this) * 3,
end = start + 3;
$cbs.slice(start,end).prop("checked",true);
});
});
Currently this code only selects the checkboxes, however I was wondering if anyone knew how to modify it so that it toggles the checkbox selection on and off?
Here's an example of my current code: "jsfiddle" - click the 1-3, 4-6 links etc to check the checkboxes.
Make the second argument to the prop("checked", ...) call depend on the "checked" status of the first (or other) checkbox in the slice:
// ...
$cbs.slice(start,end).prop("checked", !$cbs.slice(start).prop("checked"));
Here's an updated jsFiddle.
[Edit] Or to update each checkbox in the slice individually:
// ...
$cbs.slice(start,end).each(function() {
var $this = $(this);
$this.prop("checked", !$this.prop("checked"));
});
http://jsfiddle.net/ShZNF/3/
$cbs.slice(start,end).each(function() {
if ($(this).is(":checked")) {
$(this).removeProp("checked");
} else {
$(this).prop("checked",true);
}
});
http://jsfiddle.net/ShZNF/1/
Edit: Maeric's solution is better. I wasn't aware removeProp had this gotcha:
Note: Do not use this method to remove native properties such as
checked, disabled, or selected. This will remove the property
completely and, once removed, cannot be added again to element. Use
.prop() to set these properties to false instead.

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