Cloned row requesting same function [duplicate] - javascript

This question already exists:
Closed 10 years ago.
Possible Duplicate:
Call same function by a cloned list row
I am trying to make a simple calculation to work.
I have the following running:
http://jsfiddle.net/vSyK6/41/
Basically, the way it works now is this:
When you select an option on the drop down list it will display the content based on the option selected. Then when you select the same option again it will add, basically clone the same row.
Now, when the second option is selected "Option2" it will display an empty textbox. When you enter a number it will or should call the a function where we make a basic calculation. The function is already in the script.
However, when we have two empty textboxes it should call the same calculation function but calculate seperately and puts it in a different div. The div# where we display the amount is a called "amount"
Basically, it should work like this:
First Empty textbox -> 100 -> 100 * 22.38 = display result in div#1
Second Empty textbox -> 230 -> 230 * 22.38 = display in div#2
any idea on how to accomplish that ?

When cloning elements the id is cloned as well. It is best practice to create a new ID for the cloned elements, which will also help in accomplishing what you want. The same goes for the name attribute as well.
With a few modification to your code, http://jsfiddle.net/dNQVQ/3/, I was able to get what you were after. Let me first say that this might not be the ideal way to go, but it is a start. Like I said earlier the key is going to be setting unique ids for the cloned elements. What I did in this example was use a index as part of the list element id that is cloned with a matching index in an 'amount' div. This way when an input is updated the index is retrieved and then used to update the appropriate div. Additionally, I moved the function that did the calculation and updates to an anonymous function in the settimeout call. This makes it easy to use a reference to the updated input in the function call.

Joining the party quite late here :) Here is one vernon: http://jsfiddle.net/KVPwm/
ALso if its assignment bruv, put an assignment homework tag!
People around SO community are awesome folks so be truthful, guys will help man!
Use .on instead of live - recommendation. i.e. upgrade your JQ source if keen read this - What's wrong with the jQuery live method?
you have 2 document.ready functions also I chained few things for you.
Also think of using isNan check as well.
Rest you can read the code and play around a bit to make it more concise.
I have added 2 divs and using the id number to populate the stuff accordingly.
This should fit the cause :)
code
$("document").ready(function() {
/////////////////////////////////CALUCATIONS/////////////////////////////////
//setup before functions
var typingTimer; //timer identifier
var doneTypingInterval = 0; //time in ms, 5 second for example
$('input[name=Input2], input[name=Input1]').live('keyup', function() {
var str = $(this).prop("id");
var pattern = /[0-9]+/g;
var matches = str.match(pattern);
amount = parseFloat($(this).val()) * 22.38;
typingTimer = setTimeout(doneTyping(matches), doneTypingInterval);
});
$('#Input2').keydown(function() {
clearTimeout(typingTimer);
});
function doneTyping(matches) {
$('#amount'+matches).text(amount.toFixed(2) + " lbs");
}
$("#List-Option1,#List-Option2").hide();
$('#category').change(function() {
var str = $('#category').val();
if (str == 'Option1') {
var option1 = $("#List-Option1:first").clone().show();
$('#box li:last').after(option1);
}
if (str == 'Option2') {
var option2 = $("#List-Option2:first").clone().show();
$('#box li:last').after(option2);
}
});
});​

Related

jQuery .append() in for loop [duplicate]

This question already has answers here:
Why do multiple `.appendTo` calls on a newly created jQuery element only append it once?
(2 answers)
Closed 3 months ago.
I tried looking for an answer here but all of the questions related to my issue are a bit too complicated for someone who just started learning JavaScript like me.
I want to create a grid of divs with js/jquery based on user input (eg: if user chooses width = 16, then he will see a 16x16 grid).
Now, I figured, I'll add a DOM element with var $smallDiv = $('<div class="smallDiv"></div>');
And here is the loop that adds the needed number of divs based on user input:
function addDiv() {
$('#container').append($smallDiv);
}
for (i = 1; i <= divCounter * divCounter; i++){
addDiv();
}
The problem is that this will always create only one div. The loop runs the required number of times, I've checked this using console.log(). So it clearly works, but I get the feeling that each time it loops, the new div overwrites the previous. That wasn't my expectation of .append().
I've managed to get around the problem by making the $smallDiv variable a normal one (removing $ from its value, making it just text) but I would love to know how are these two variables different and why does one work in the above scenario but the other does not.
And make it easy on me, I just started learning JS/jQuery.
In the loop, you are appending the same dom element reference($smallDiv) multiple times, which means the element will be added only once.
Instead in each iteration of the loop, you need to create new instance - you can use .clone() to do that.
function addDiv() {
$('#container').append($smallDiv.clone());
}
As an alternative to Arun P Johny solution, this seems to work as well:
var smallDiv = '<div class="smallDiv"></div>'
function addDiv() {
$('#container').append(smallDiv);
}
for (i = 1; i <= divCounter * divCounter; i++){
addDiv();
}
This way its not the same dom element but instead we use a simple string for append.

How to get jquery selector seeing updated dom in change handler

I'm fairly new to javascript and jQuery. I've searched for answers to this question, but have had no luck, though I bet there are some in here. So advance apologies if this is a dup.
Markup has 3 checkboxes with different classes, and one class in common. I want to notice when the number of boxes checked in either of two classes changes, or rather when there is a transition between at least one box in two of the classes being checked or unchecked. The two interesting classes are named "professional" and "vendor", and the class in common is "account_type_checkbox".
When the page is ready, I count the number of checked "professional" and "vendor" boxes with:
jQuery("input.professional[checked='checked'], input.vendor[checked='checked']").length
This appears to work correctly. I have a "change" event handler on checkboxes in the common class that does the same count when it triggers. But when the event triggers, it gets the same count as it did on page load - i.e. it doesn't see the updated DOM with the modified checked attribute.
I've put a jsfiddle for this at http://jsfiddle.net/cm280s9z/1
Could someone please help me fix this, and/or explain why my code doesn't work the way I expected it to?
http://jsfiddle.net/cm280s9z/3/
Use alert($(":checkbox:checked").length); to get the sum of all marked checkboxes.
There are several other ways of doing this too, as pointed out in this thread, such as doing it by classes on a checkbox:
calculate the number of html checkbox checked using jquery
Maybe you will find this useful: http://jsfiddle.net/cm280s9z/6/
Here's a cleaned up version (not saying it's the best ever) of what you had, showing the :checked.
Reasons why this code is good:
storing the jQuery object checkboxes means it won't have to re-jquery-objectify it every time.
grabbing objects by certain [vague or lengthy] selectors can be more strenuous on jQuery. Grabbing by this class means it'll be more specific as well. We can further filter out checked using .filter. Extra Tip: If traversing the DOM, I like to grab a container that's fairly unique and use .find() to help me get at the descendants.
functions can bring some order and organization to what you're doing.
comments are your friend.
Hope this helps!
var GLOB = GLOB || {};
jQuery(document).ready(function () {
// Define
var checkboxes = jQuery('.account_type_checkbox');
var get_checkbox_count = function(checkboxes){
return checkboxes.filter(':checked').length;
};
var do_business = function(){
alert('transitioned to business');
};
var do_personal = function(){
alert('transitioned to personal');
};
// Initialize
GLOB.business_count = get_checkbox_count(checkboxes);
alert('GLOB.business_count = ' + GLOB.business_count);
// Events
checkboxes.change(function(){
var cur_count = get_checkbox_count(checkboxes);
var add_business = (cur_count > 0);
var no_business = (GLOB.business_count < 1);
// If any are selected it's business, where previously none were checked.
var transition_business = (add_business && no_business);
// If none are selected it's personal, if previously any were checked.
var transition_personal = (!add_business && !no_business)
if (transition_business)
do_business();
if (transition_personal)
do_personal();
});
});

How to create a string and use a function that's named after it?

Sorry for bad wording in the question but it's hard to explain for me. I'm using several bxsliders on a page and some are placed in hidden divs. Unfortunately images are not shown in the slider after making the parent div visible unless the slider is reloaded (See here: bxSlider within show/hide divs). So let's say I initiate the sliders at the beginning with:
var slider_0=$("#slider_0 .bxslider").bxSlider({
//bxslider options here
});
var slider_4=$("#slider_4 .bxslider").bxSlider({
//bxslider options here
});
var slider_7=$("#slider_7 .bxslider").bxSlider({
//bxslider options here
});
The sliders are not consecutively numbered but there is a navigation and if I click the 7th element it leads to slider_7. So I could get the index of the clicked item with:
$(this).index();
When I call slider_7.reloadSlider(); it would work but I don't know which slider the user clicks and which number it has. So would it be possible to call that with a created string like this:
slider_name='slider_'+$(this).index();
slider_name.reloadSlider();
works not of course. Is there a way to do it?
I would create a dictionary with strings as keys and functions as values. Then, you could have O(1) lookup of the functions you're targeting.
In general, you can do it like so:
// set up your dictionary
var dictionary = {};
// add your functions
dictionary['methodName'] = function() {};
// call the functions
dictionary['methodName']();
So, for your example, you could do:
dictionary['slider_7'] = slider_7.reloadSlider;
dictionary['slider_'+$(this).index()]();
You could trigger it with
window["slider_" + $(this).index()].reloadSlider()
Although, I'm not sure whether your approach is the best. I think I'd go with arrays or with object (as a key-value pairs)
Try this:
slider_name='slider_'+$(this).index();
$("#" + slider_name + " .bx_slider").reloadSlider();
Found a working solution:
eval("slider_" + $(this).index()).reloadSlider();
Its not entirely clear here what you want/are trying to do. What it seems like you want to do is get a programmatic handle on a specific slider when a user clicks a specific part of your page. You do not accomplish this by eval()ing a string...that's what event handlers are for. So create a click event handler and in that event handler
$('#idOfWhatTheUserClicksOn').click(function(event) {
var slider = document.getElementById('#idOfRelatedSlider');
$(slider).bxSlider();
//if you need the current value of the slider you can get that too
var value = slider.value;
});
You could achieve the same with fewer LOC by using a class instead of id's with different handlers, but the concept is the same.
var slider_cache = [
$("#slider_0 .bxslider").bxSlider(),
$("#slider_1 .bxslider").bxSlider(),
$("#slider_2 .bxslider").bxSlider()
];
...
slider_cache[$(this).index()].reloadSlider();

About a loop that creates dynamic buttons, but cannot give proper values [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Javascript infamous Loop problem?
I am having a small issue, and it would be very nice if some of you could realize about what kind of logic is missing here, since I cannot seem to find it:
I have an array with the results of some previous operation. Let's say that the array is:
var results = [0, 1];
And then I have a bunch of code where I create some buttons, and inside a for loop I assign a different function to those buttons, depending on the position of the array. The problem is that for some reason, all the buttons created (two in this case) come out with the function assigned to the last value of the array (in this case, both would come out as one, instead of the first with 0 and the second with 1)
This is the code:
for (var i = 0; i < results.length; i++) {
var br2 = b.document.createElement("br");
var reslabel = b.document.createTextNode(Nom[results[i]].toString());
var card = document.createElement("input");
card.type = "button";
id = results[i]; // this is the problematic value.
card.onclick = newcard; // this function will use the above value.
card.value = "Show card";
divcontainer.appendChild(br2);
divcontainer.appendChild(reslabel);
divcontainer.appendChild(card);
}
As it is, this code produces as many buttons as elements in the array, each with its proper label (it retrieves labels from another array). Everything is totally fine. Then, I click the button. All the buttons should run the newcard function. That function needs the id variable, so in this case it should be:
First button: runs newcard using variable id with value 0
Second button: runs newcard using variable id with value 1
But both buttons run using id as 1... why is that?
It might be very simple, or maybe is just that in my timezone is pretty late already :-) Anyways, I would appreciate any comment. I am learning a lot around here...
Thanks!
Edit to add the definition of newcard:
function newcard() {
id = id;
var toerase = window.document.getElementById("oldcard");
toerase.innerHTML = "";
generate();
}
the function generate will generate some content using id. Nothing wrong with it, it generates the content fine, is just that id is always set to the last item in the array.
Your id is a global variable, and when the loop ends it is set to the last value on the array. When the event handler code runs and asks for the value of id, it will get that last value.
You need to create a closure to capture the current results[i] and pass it along (this is a very common pitfal, see Javascript infamous Loop problem?). Since newcard is very simple, and id is actually used in generate, you could modify generate to take the id as a parameter. Then you won't need newcard anymore, you can do this instead:
card.onclick = (function(id) {
return function() {
window.document.getElementById("oldcard").innerHTML = "";
generate(id);
};
}(results[i]));
What this does is define and immediately invoke a function that is passed the current results[i]. It returns another function, which will be your actual onclick handler. That function has access to the id parameter of the outer function (that's called a closure). On each iteration of the loop, a new closure will be created, trapping each separate id for its own use.
Before going on, a HUGE thank you to bfavaretto for explaining some scoping subtelties that totally escaped me. It seems that in addition to the problems you had, you were also suffering from scoping, which bit me while I was trying to craft an answer.
Anyway, here's an example that works. I'm using forEach, which may not be supported on some browsers. However it does get around some of the scoping nastiness that was giving you grief:
<html>
<body>
<script>
var results = [0,1];
results.forEach( function(result) {
var card = document.createElement("input");
card.type = "button";
card.onclick = function() {
newcard( result );
}
card.value = "Show card";
document.body.appendChild(card);
});
function newcard(x) {
alert(x);
}
</script>
</body>
</html>
If you decide to stick with a traditional loop, please see bfavaretto's answer.

each() function returning Null or Objects

Hi I am newbie in programming and I am trying to learn and make it work with each(). Bear with me. I try my best to learn from here and you.
I am trying to go through the item per product in a catalog for the specific prices: either original and sale from the page.
then calculate the % for discount
print discount %
check to compare the percent to color the background: brown, yellow and red.
Now, I test each line to see if it works or not.
salecost = $(this).find('#sale').html(); returns a few nulls before displays amount with dollar signs. Weird couldn't figure that one out. Replace() isn't working right - couldn't get it working. It is supposed to remove dollar sign.
Also, I am not sure how it goes with compare -- do i write statement correctly?
Thank you in advance for the help
var salecost;
var originalcost;
var percentDiscount;
var percent;
function calculate(sale, original)
{
percentDiscount = eval((sale/original)*100);
document.getElementById("percentoff").innerHTML=parseInt(percentDiscount) + '%';
}
$(document).ready(function(index){
$('.item').each(function(){
salecost = $(this).find('#sale').html();
salecost = salecost.replace(/[^\d\.]/g,"");
alert (salecost);
originalcost = $('#sale').html();
originalcost = originalcost.replace(/[^\d\.]/g,"");
alert (originalcost);
percent = calculate(salecost,originalcost);
alert(percent);
if(percent<30)
{
$("div#percentoff").css({"background-color":"brown", "padding":"5px 0"});
}
if(percent<50){
$("div#percentoff").css({"background-color":"yellow", "padding":"5px 0"});
}
if(percent<70){
$("div#percentoff").css({"background-color":"red", "padding":"5px 0"});
}
});
});
This is not required
$(this).find('#sale').html();
You can replace this using
$("#sale").html();
since id will be unique in a document. If you have more than one element with the same id then your HTML is invalid.
Edit
Remove the id from the span tag.
<span class="price">S$319</span>
This will find all the spans[here only 1] with class name price inside the parent div. No need to use .html() here, you can use .text()
$(this).find('span.price').text();
You should move your var statements to within the each function so they're not global.
You don't need to you the eval, (sale/original)*100 will work by it self.
It's better to use consistent style, your calculate function could be written using jquery.
$("#percentoff").html(percentDiscount) + '%');
casting is unnecessary for most cases in javascript, concatenating a number with a string will produce a string.
your calculate function should return percentDiscount;
Instead of using .css() it would be better to use .addClass that way it's easy to undo with .removeClass, the style is all the the style sheet and you can use jquery to select the elements with the class.

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