Develop Reference

Keeping track of items added to a page on button click

I have a for loop inside a button for an image gallery. When you click the button it will get the next group of items and add them to the page until there are no items left to grab. I was originally keeping track of the position in the array by adding the amount of items that should be added with each click to the previous value on each click. I wanted to change these vars to const, but if const in ES6 is not supposed to change (stay constant) how do you achieve this same result by not changing the value of the variables? Are my methods of keeping track of the current count of items not how I should be doing this?
var itemCurrent = 10; // Starting number of items on page.
var itemsAdded = 15; // Number of items to add to page per button click.
document.getElementById('myButton').addEventListener('click', function() {
for (let i = itemCurrent; i < itemCurrent + itemsAdded; i++) {
if(i < data.projects.length) {
//Do Stuff---------------------
}
}
itemCurrent = itemCurrent + itemsAdded;
});

I thought maybe there would be a more elegant way to do what I wanted, but it seems using let instead of var and leaving everything the way it was is the best way.

Unable to set selected value with easyDropDown.js

I am attempting to use the easyDropDown.js add on to style my drop boxes but I have encountered an issue. My drop box is not statically created. When the webpage is loaded an array is used to append the drop down list. This drop box appears on multiple pages of my website and I am attempting to set it up so that when the user makes a selection on one page, that selection carries to every page.
Here's a step by step play-through of what the code is doing:
When the page is started it appends the easyDropDown list so that all the values are there.
$('#homeSelectSite').empty();
s = "";
s = "<option value='site'>Site</option>";
for (var i = 0; i < Sites.length; i++) {
s = s + "<option value='" + Sites[i].SiteID + "'>" + Sites[i].SiteID + " " + Sites[i].SiteName + "</option>";
}
$('#homeSelectSite').append(s);
Note: Sites is the array that I am using to fill the drop box.
Now once the drop box list has been created I need to set what value is selected. This value is set in the sessionStorrage if the user has made a selection on another page.
$('#homeSelectSite').easyDropDown();
var selectedSite = sessionStorage.getItem("CurrentSiteID");
if (selectedSite != undefined && selectedSite != null) {
$('#homeSelectSite').val(selectedSite);
}
So what the code is doing is this: emptying the current drop box, appending it with new values, styling it with easyDropDown, and finally setting the selected value. For some reason this will not work. The appending and styleing are working just fine but it will not allow me to set the selected value. I have also tried using this:
$('#homeSelectSite').easyDropDown('select', selectedSite);
Is there a reason why I cannot set the selected value? This all works if I remove everything related to easyDropDown.

I had a similar issue today as I was trying to set the selected value of a dropdown using easyDropDown.
What I did to fix it was to find out the index of the to-be selected option, rather than selecting it by value.
In your case it would be something like:
var index = 0;
$('#homeSelectSite option').each(function(i, item) {
if ($(this).val() === selectedSite) {
index = i;
}
});
$('#homeSelectSite').easyDropDown('select', index);
Hope it helps.

it looks like there's a bug in easyDropDown 2.1.4
Line 326 should be changed from:
index = self.$select.find('option[value='+index+']').index() - 1;
to:
index = self.$select.find('option[value='+index+']').index();
This will only solve the fact that easyDropDown was selecting the previous item instead of the one you wanted, but I'm not sure this would solve your issue. And yes, you must use the 'select' method from the plugin instead of 'val'.

count checkboxes in a form using javascript

I have quite a lot of check boxes on one form. The check boxes are in different sections of the form. I would like to count the number of checkboxes at the end of each section on my form.
For example I have 6 sections within my form and I have between 6 and 10 checkboxes within each section. I would like to have a textbox with a number value at the end of each section telling me how many check boxes were check within that particular section.
Does anyone have a script for that? I have a snippet from support staff but they don't have a full solution and I don't know JavaScript well enough to finish it. I'm through trying to figure it out so i can finish it. Here is the snippet they sent me:
<script type="text/JavaScript">
function countcheck(checkName){
inputElems = document.getElementsByName(checkName);
count = 0;
for (i = 0; i < inputElems.length; i++) {
if (inputElems.checked === true) {
count++;
document.getElementById("teval_engage7").value = count;
}
}
}
</script>
The script will only count checked checkboxes within that group only. Basically you will need a function for each of your checkbox so that you can have separated counters. This will also require an attribute to your checkbox according to the function in question:
onclick="countcheck(this.name);"

var cb_counts = {};
var inputs = document.getElementsByTagName('input');
for (var i = 0; i < inputs.length; i++) {
var input = inputs[i];
if (input.type = 'checkbox' && input.checked) {
if (cb_counts[input.name]) {
cb_counts[input.name]++;
} else {
(cb_counts[input.name] = 1);
}
}
}
Now the object cb_counts contains properties with the name of each group of checkboxes, and the values are the counts. Do with this what you wish.

Thanks for the quick reply. I use a application call rsform which helps to make forms. On the script I have "teval_engage7" is the text box which stores the value of the number of checkboxes that have been checked. "onclick="countcheck(this.name);"" is the trigger I place under each checkbox question. So when I go to the form and click on a checkbox with that trigger attached to it, the value of "1" shows up in the teval_engage7 text box. The next check box I click on then shows "2" in the teval_engage7 text box. My question is, can you te me using this script you wrote where the values are stored so I can substitute that name for my textbox name. Also, do I use my same trigger "onclick="countcheck(this.name);"" to attach to my checkbox attibute area to trigger the count?
Thanks

Check boxes contradicting each other

I have a project that is "almost" done. I've gotten a ton of help here and I'm hoping I'll be able to finalize this project soon. I have a form with checkboxes that represent different attributes for 3 different items. As a user checks a specific checkbox I have whichever item that it does not correspond to hide, as well as any attribute that does not go with the one that was checked becomes disabled and the text color turns a light grey. So the only boxes that would still be active would be the ones that go together for said item.
I can get that all to work just fine (I think). But there are a few attributes that correspond to more than one item. If you look at my example (link provided)
If you check the 'Economy' chekcbox only 1 grey box 'Bernini' is displayed and a lot of other checkboxes become disabled, which is correct. Un-check it and everything is enabled and visible again.
If you check the 'Tape-in Bottom Rail' checkbox 2 grey boxes 'Bernini & Picasso' are displayed which is also correct as that attribute 'Tape-in Bottom Rail' applies to both. Un-check it and everything is enabled and visible again.
The issue I have is, IF you check both the 'Economy' & 'Tape-in Bottom Rail' then Un-check either of them, the wrong attributes become enabled and the visible grey boxes no longer correspond correctly.
I though I should use an 'else if' or another 'if' statement but if so I have not figured out how to get it to work correctly.
Here is the JS I'm using so far, this is for only 1 of the functions.
function bannerBernini() {
if (document.checkForm1.att_2.checked || document.checkForm1.att_5.checked || document.checkForm1.att_6.checked || document.checkForm2.att_9.checked || document.checkForm2.att_15.checked || document.checkForm3.att_23.checked)
{
var berninis = document.querySelectorAll('.picasso, .matisse, .picasso-matisse');
for (var i = 0; i < berninis.length; i++) {
berninis[i].style.color="#d1d1d1";}
var not_bernini = document.querySelectorAll('#att_3, #att_10, #att_11, #att_13, #att_14, #att_16, #att_17, #att_18, #att_19, #att_20, #att_21, #att_22, #att_24');
for (var j = 0; j < not_bernini.length; j++){
not_bernini[j].disabled=true;}
document.getElementById("Picasso").style.display="none";
document.getElementById("Matisse").style.display="none";
}
else
{
var berninis = document.querySelectorAll('.picasso, .matisse, .picasso-matisse');
for(var i = 0; i < berninis.length; i++) {
berninis[i].style.color="";}
var not_bernini = document.querySelectorAll('#att_3, #att_10, #att_11, #att_13, #att_14, #att_16, #att_17, #att_18, #att_19, #att_20, #att_21, #att_22, #att_24');
for (var j = 0; j < not_bernini.length; j++){
not_bernini[j].disabled=false;}
document.getElementById("Picasso").style.display="";
document.getElementById("Matisse").style.display="";
}}
Here is the sample which I hope makes sense:
http://jsfiddle.net/g_borg/48uhn/1/
Thanks in advance for any assistance. I know some will say I should use jQuery, I would but as this is my 1st time trying to code with javascript and I'm not familiar with jQuery I'd prefer to try to keep this where I still understand the code.

Show/hide table row based on value of a cell

I am using the range slider from JQuery-UI (http://jqueryui.com/slider/#range) which a user uses to pick a price range, and I want to show/hide table rows depending on whether or not they fall inside the range selected by the user.
This is what I have found from other answers: the following code hides the table row that has a cell in column 9 containing the value 10.
$("tr").find("td:nth-child(9):contains(10)").parent().hide();
What I am trying to do is "hide where the value in the cell is less than 10".
I have tried the following:
$("tr").find("td:nth-child(9):lt(10)").parent().hide();
But ":lt" is a method that applies to indexes, not values (I think).
Can anyone help me out please?

You're not going to be able to do this with selectors alone. You can use .filter for more specific functionality:
$("tr").find("td:nth-child(9)").filter(function () {
return parseInt($(this).text()) < 10;
}).parent().hide();
A brief note that :contains doesn't work very well for your first example either since it will apply to elements that contain "100."

Using some of your code from above, you could probably do something similar to this:
for(var i = 0; i < 10, i++) {
$("tr").find("td:nth-child(9):contains(" + i + ")").parent().hide();
}
You may have to add a few things to get what you need, but I think this should point you in the right direction!