use JavaScript to manipulate multiple (predictably) named DIVs - javascript

I want to execute a function repeatedly on groups of predictably named html divs.
I am using a drag and drop relationship shown below in which dragging text into a certain div space "target" causes that text to appear in another div called "saves".
<script type="text/javascript">
function OnDragStart (event) {
if (event.dataTransfer) {
var format = "Text";
var textData = event.dataTransfer.getData (format);
}
}
function OnDropTarget (event) {
if (event.dataTransfer) {
var format = "Text";
var textData = event.dataTransfer.getData (format);
if (!textData) {
textData = "<span style='color:red'>The data transfer contains no text data.</span>";
}
var savesDiv = document.getElementById ("saves");
savesDiv.innerHTML = savesDiv.innerHTML + "<br />" + textData;
}
else {
alert ("Your browser does not support the dataTransfer object.");
}
if (event.stopPropagation) {
event.stopPropagation ();
}
else {
event.cancelBubble = true;
}
return false;
}
</script>
The script in combination with the corresponding html works perfectly for the target and saved divs... but what i would really like is to apply the same script to a set of divs pairs named
(target1, saves1 )
(target2, saves2)
(target3,saves3)
(target4 saves4) etc etc
with numbers in div ids going up every time by 1 up to (target20, saves 20) ... Without obviously repeating the same script 20 times with different id names when referring to all the target and saved divs.
I realize this is a total newbie question but I'm really interested to learn the different ways this can be approached.

Give a common class name to these divs so when the dragdrop event occurs, it can be handled using the class name instead of the id; that is, like $('.someClass').someEvent instead of $('#target1'). You can get its id property inside this function using $(this).attr("id").
So if you have "target1" as the id, get the last character ("1") using the JavaScript substring function; you can write generic code such as this:
$('.someClass').someEvent(function(){
var id=$(this).attr(id);
var lastno=id.substring(id.lastIndexOf("t"),id.length);
//now rest of code
$("#saves"+lastno).val($("#target"+lastno).val());
});

Related

Javascript - Submit Text Field, Show Div, Hide All Others

I have a simple form (text field and submit button). I am trying to have the user submit a number, and the resulting number will display one div (from a set of divs).
I tried using this example as a base (when the user clicks a link, it shows a div, but hides others).
My test is below:
var divState = {};
function showhide(oFrm) {
var dividnum = oFrm.Inputed.value;
var prepar = "para";
var divid = prepar + theInput; /* should result in something like "para52" */
divState[divid] = (divState[divid]) ? false : true;
//close others
for (var div in divState){
if (divState[div] && div != divid){
document.getElementById(div).style.display = 'none';
divState[div] = false;
}
}
divid.style.display = (divid.style.display == 'block' ? 'none' : 'block');
}
http://jsfiddle.net/LfzYc/431/
Note: I am NOT proficient in JavaScript at all, which is why I am having difficulty.
Also, I'd like to add a function ... if the number entered is not between 1-4, show a different div, maybe with the id paraEnd.
Please look at the jsFiddle based on your one. I hope I've done what you want. I changed the showhide function and your HTML (fixed div's IDs and added one more div#paraEnd). I'd suggest you refactoring your code.
You should use jQuery to have an easy way to manipulate the DOM.
Using jQuery I made an example for you, just change your JS and paste mine:
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
(function ($) {
// get the paragraphs
var paragraphs = $('.paragraph');
// form submit
$('#paragraphform').submit(function (e) {
// prevent the event to flow
e.preventDefault();
// get the input value
var value = $('#Inputed').val() - 1;
// reset all divs removing active css class
paragraphs.removeClass('active');
$('.error').removeClass('active');
// verify if the value doens't exist
if(value < 0 || value > paragraphs.length - 1) {
$('.error').addClass('active');
return;
}
// show the active div
paragraphs.eq(value).addClass('active');
});
})(jQuery);
</script>
Is that what you need?
If you not familiar with jQuery, this is the jquery Learn Center:
https://learn.jquery.com/
And this is a nice tutorial for beginners:
http://www.tutorialspoint.com/jquery/

Element innerHTML getting rid of event listeners [duplicate]

This question already has answers here:
Is it possible to append to innerHTML without destroying descendants' event listeners?
(13 answers)
Closed 6 years ago.
I have a function for adding buttons to a page.
var count = 0;
function createOnclickFunction(number)
{
return function()
{
alert("This is button number " + number);
}
}
function addButton(data)
{
var newbutton = "..." //creates string from data
var element = document.getElementById("mydiv");
var children = element.children;
element.innerHTML = newbutton + element.innerHTML;
var currentCount = count;
children[0].onclick = createOnclickFunction(currentCount)
count++;
}
It basically creates a button into the html based off some data.
Every time I add a button, I would like it to be added to the start of div #mydiv, and since newbutton is also not an Element, but a String, I have to modify the innerHtml to add it to the start of #mydiv.
Afterwards, I must get the element (to add an onclick), by getting the first child of #mydiv.
However, after adding a second button to my page, the first button onclick no longer works.
If I modify my code to only add one button, everything works fine.
So now, only the top button (the latest added button), can be clicked.
How can I fix this?
I've also tried to use element.firstChild instead of element.children[0].
Thanks in advance everyone!
EDIT:
Here is a jsfiddle: ( as you can see the only button that works is stackoverflow )
https://jsfiddle.net/7c7gtL26/
It seems you misunderstood the problem. The problem is that you are overwriting innerHTML in order to insert contents.
Never use innerHTML to insert contents. It will remove all the internal data, like event listeners. This is what happens here.
If you want to prepend some HTML string, use insertAdjacentHTML:
var count = 0;
function createOnclickFunction(number) {
return function() {
alert("This is button number " + number);
}
}
function addButton(data) {
var newbutton = "<button>Click me</button>" //creates string from data
var element = document.getElementById("mydiv");
element.insertAdjacentHTML('afterbegin', newbutton);
var children = element.children;
children[0].onclick = createOnclickFunction(count)
count++;
}
addButton();
addButton();
addButton();
<div id="mydiv"></div>

Using this within functions called with onclick event in Javascript

I'm currently building a small Todo list application using vanilla Javascript but I'm having some issues creating a delete button that onClick removes it's parent element.
From what I have read, when an onClick is called in Javascript the this keyword can be used to refer to the element that called the function. With this in mind I have the following code:
window.onload = initialiseTodo;
function addRecord(){
var title = document.getElementById('issueTitle');
var issueContent = document.getElementById('issueContent');
var contentArea = document.getElementById('contentArea');
if(title.value.length > 0 && issueContent.value.length > 0){
var newItem = document.createElement('div');
newItem.id = 'task' + count++;
newItem.className = 'task';
newItem.innerHTML = '<div class="taskbody"><h1>' + title.value + '</h1>'+ issueContent.value + '</div><div class="deleteContainer">'
+ '<a class="delete">DELETE</a></div>';
contentArea.appendChild(newItem);
assignDeleteOnclick();
}
}
function deleteRecord(){
this.parentNode.parentNode.parentNode.parentNode.removeChild(this.parentNode.parentNode);
}
function assignDeleteOnclick(){
var deleteArray = document.getElementsByClassName('delete');
for(var i=0;i<deleteArray.length;i++){
deleteArray[i].onclick= deleteRecord();
}
}
function initialiseTodo(){
var btn_addRecord = document.getElementById('addRecord');
btn_addRecord.onclick = addRecord;
}
Basically I have a form that has two fields. When these fields are filled and the addRecord button is clicked a new div is added at the bottom of the page. This div contains a delete button. After the creation of this I assign an onclick event to the delete button which assigns the deleteRecord function when the delete button is clicked. My issue is with the deleteRecord function. I have used this to refer to the calling element (the delete button) and wish to remove the task div that is the outermost container however I current get a message that says: 'Cannot read property 'parentNode' of undefined ' which suggests to me the this keyword is not working correctly.
Any help would be greatly appreciated.
I've added the full code to a fiddle.
http://jsfiddle.net/jezzipin/Bd8AR/
J
You need to provide the element itself as a parameter. I did so by changing the html to include onclick="deleteRecord(this)" to make it a little easier to deal with. This means you can remove the assignDeleteOnclick() function
function deleteRecord(elem){
elem.parentNode.parentNode.remove();
}
Demo
You might style the .content to be hidden better if there are no elements to prevent that extra white space
Edit
Since you don't want an inline onclick, you can do it with js the same:
function deleteRecord(elem){
elem.parentNode.parentNode.remove();
}
function assignDeleteOnclick(){
var deleteArray = document.getElementsByClassName('delete');
for(var i=0;i<deleteArray.length;i++){
// Has to be enveloped in a function() { } or else context is lost
deleteArray[i].onclick=function() { deleteRecord(this); }
}
}
Demo

exchanging values in a select list with jQuery

I'm trying to swap select option values with jQuery when a links clicked, at the moment its just resetting the select when the links clicked, not sure what's going wrong?:
jQuery:
$(function () {
$("#swapCurrency").click(function (e) {
var selectOne = $("#currency-from").html();
var selectTwo = $("#currency-to").html();
$("#currency-from").html(selectTwo);
$("#currency-to").html(selectOne);
return false;
});
});
JS Fiddle here: http://jsfiddle.net/tchh2/
I wrote it in a step-by-step way so it is easier to understand:
$("#swapCurrency").click(function (e) {
//get the DOM elements for the selects, store them into variables
var selectOne = $("#currency-from");
var selectTwo = $("#currency-to");
//get all the direct children of the selects (option or optgroup elements)
//and remove them from the DOM but keep events and data (detach)
//and store them into variables
//after this, both selects will be empty
var childrenOne = selectOne.children().detach();
var childrenTwo = selectTwo.children().detach();
//put the children into their new home
childrenOne.appendTo(selectTwo);
childrenTwo.appendTo(selectOne);
return false;
});
jsFiddle Demo
Your approach works with transforming DOM elements to HTML and back. The problem is you lose important information this way, like which element was selected (it is stored in a DOM property, not an HTML attribute, it just gives the starting point).
children()
detach()
appendTo()
That happens because you remove all elements from both <select> fields and put them as new again. To make it working as expected you'd better move the actual elements as follows:
$("#swapCurrency").click(function(e) {
var options = $("#currency-from > option").detach();
$("#currency-to > option").appendTo("#currency-from");
$("#currency-to").append(options);
return false;
});
DEMO: http://jsfiddle.net/tchh2/2/
You are replacing the whole HTML (every option) within the <select>. As long as each select has the same amount of options and they correspond to each other, you can use the selected index property to swap them:
$("#swapCurrency").click(function (e) {
var selOne = document.getElementById('currency-from'),
selTwo = document.getElementById('currency-to');
var selectOne = selOne.selectedIndex;
var selectTwo = selTwo.selectedIndex;
selOne.selectedIndex = selectTwo;
selTwo.selectedIndex = selectOne;
return false;
});
JSFiddle

jQuery removing elements from DOM put still reporting as present

I have an address finder system whereby a user enters a postcode, if postcode is validated then an address list is returned and displayed, they then select an address line, the list dissappears and then the address line is split further into some form inputs.
The issue i am facing is when they have been through the above process then cleared the postcode form field, hit the find address button and the address list re-appears.
Event though the list and parent tr have been removed from the DOM it is still reporting it is present as length 1?
My code is as follows:
jQuery
// when postcode validated display box
var $addressList = $("div#selectAddress > ul").length;
// if address list present show the address list
if ($addressList != 0) {
$("div#selectAddress").closest("tr").removeClass("hide");
}
// address list hidden by default
// if coming back to modify details then display address inputs
var $customerAddress = $("form#detailsForm input[name*='customerAddress']");
var $addressInputs = $.cookies.get('cpqbAddressInputs');
if ($addressInputs) {
if ($addressInputs == 'visible') {
$($customerAddress).closest("tr").removeClass("hide");
}
} else {
$($customerAddress).closest("tr").addClass("hide");
}
// Need to change form action URL to call post code web service
$("input.findAddress").live('click', function(){
var $postCode = encodeURI($("input#customerPostcode").val());
if ($postCode != "") {
var $formAction = "customerAction.do?searchAddress=searchAddress&custpc=" + $postCode;
$("form#detailsForm").attr("action", $formAction);
} else {
alert($addressList);}
});
// darker highlight when li is clicked
// split address string into corresponding inputs
$("div#selectAddress ul li").live('click', function(){
$(this).removeClass("addressHover");
//$("li.addressClick").removeClass("addressClick");
$(this).addClass("addressClick");
var $splitAddress = $(this).text().split(",");
$($customerAddress).each(function(){
var $inputCount = $(this).index("form#detailsForm input[name*='customerAddress']");
$(this).val($splitAddress[$inputCount]);
});
$($customerAddress).closest("tr").removeClass("hide");
$.cookies.set('cpqbAddressInputs', 'visible');
$(this).closest("tr").fadeOut(250, function() { $(this).remove(); });
});
I think you're running into the same issue I recently ran into. If you have a variable pointing to 5 DIV's (example: var divs = $('.mydivs');) and then you call jQuery's remove() on one of the DIV's, like so: divs.eq(0).remove() you'll see that divs.size() still returns 5 items. This is because remove() operates on the DOM. However... if after calling remove() you then re-set your variable: divs = $('.mydivs'); and get the size you'll now get the correct size of the array. I've added sample code displaying this below:
// get all 5 divs
var d = $('.dv');
// remove the first div
d.eq(0).remove();
// you would expect 4 but no, it's 5
alert(d.size());
// re-set the variable
d = $('.dv');
// now we get 4
alert(d.size());

Categories