OnClick works only for last appended child - javascript

I have such code:
var pageCount = 5; //for example, doesn't really matter
var paginationList = document.createElement("ul");
paginationList.className = "pagination";
for(var i = 1; i <= pageCount; i++){
var paginationNode = document.createElement("li");
var paginationLink = document.createElement("a");
paginationLink.innerHTML = i;
paginationLink.href = "#";
paginationLink.onclick = function(){ console.log("yay"); }; //removed loadProperties here
paginationNode.appendChild(paginationLink);
paginationList.appendChild(paginationNode);
}
divxml.innerHTML = "";
divxml.appendChild(paginationList);
//code replaced by this comment inserts a lot of content to divxml
//for this bug or something to work, you need next line
divxml.innerHTML += "<br>";
divxml.appendChild(paginationList);
As you can see, I'm doing pagination here. The problem is that first pagination buttons don't work, I can't see yay in console when I click on them, but the second and last ones do work (I see yay in console when I click on them). What's wrong, How do I fix that?

You will have to create two list elements and two sets of list item elements for this to work:
var pageCount = 5; //for example, doesn't really matter
var paginationList1 = document.createElement("ul");
var paginationList2 = document.createElement("ul");
paginationList1.className = paginationList2.className = "pagination";
for(var i = 1; i <= pageCount; i++){
paginationList1.appendChild(createPaginationLink(i));
paginationList2.appendChild(createPaginationLink(i));
}
document.body.appendChild(paginationList1);
document.body.appendChild(document.createElement("br"));
document.body.appendChild(paginationList2);
function createPaginationLink(text) {
var paginationNode = document.createElement("li");
var paginationLink = document.createElement("a");
paginationLink.innerText = text;
paginationLink.href = "#";
paginationLink.addEventListener("click", function(){ console.log("yay"); }); //removed loadProperties here
paginationNode.appendChild(paginationLink);
return paginationNode;
}
And as stated in the other answer, mutating innerHTML will cause your elements to be re-created without their event listeners, so instead create and append your <br/> element using createElement and appendChild.
Codepen

divxml.innerHTML += "<br>";
Reading from innerHTML converts the DOM into HTML. The HTML does not have the event handlers that were attached to the DOM.
Writing the HTML back to the innerHTML (after appending <br> to it) converts the HTML to DOM and overwrites the DOM that was there before.
You have now destroyed the event handlers.
Don't use innerHTML.

Related

Javascript append html tags before for loop

I have the following code below, where I am trying to create a ul tag, and inside it a for loop to dynamically create li elements. A separate closing ul tag is created after the loop is completed.
The code works. Except for the problem that the code does not run in order like I want it to. The ul tags are closed before the for loop can be processed into the page, resulting in the html looking more like:
<ul></ul><li>0</li><li>1</li>...
var insidethediv = document.getElementById("insidethediv");
var numero = 5;
insidethediv.innerHTML = "<ul>";
for (i = 0; i < 5; i++){
insidethediv.innerHTML += "<li>"+i+"</li>";
}
insidethediv.innerHTML += "</ul>";
<div id="insidethediv"></div>
Assigning directly to innerHTML is a bad idea here. innerHTML expects a complete html fragment, i.e. all open tags should be closed. But here you are assigning to a partial html fragment while you are building it. Try to create the complete html first and then assign it to innerHTML, e.g. like so:
var insidethediv = document.getElementById("insidethediv");
var numero = 5;
var s = "<ul>";
for (i = 0; i < 5; i++){
s += "<li>"+i+"</li>";
}
s += "</ul>";
insidethediv.innerHTML = s;
I personally prefer to use document.createElement(tag name) and Element.append(created element reference) functions. In this way we are able to manipulate each individual <li> tag (such as assign different colors) and render the HTML tags dynamically instead of jamming everything into a string then insert it as an innerHTML element.
var insidethediv = document.getElementById("insidethediv");
var numero = 5;
var ul_element = document.createElement("ul");
insidethediv.append(ul_element);
var li_element;
for (var i = 0; i < 5; i++){
li_element = document.createElement("li");
ul_element.append(li_element);
li_element.innerHTML = i;
}
<div id="insidethediv"></div>

javascript adding click events to buttons in a loop

The code below gets info from xml file.
I succesfully presents the id and name of each planet with a button.
I want to add an onclick event on the button.
Problem now is: it does add the onclick event but only on the last button created in the loop.
What am i doing wrong? Why doesnt it create a onclick event for each button, but only for the last one in loop?
function updatePlaneten() {
var valDiv, planets, valButton, textNode;
// Get xml files
planets = this.responseXML.getElementsByTagName("planeet");
// loop through the <planet> tags
for (var i = 0; i < planets.length; i++) {
valDiv = ''; // clear valDiv each time loop starts
// Get the id and the name from the xml info in current <planet> tag
valDiv += planets[i].getElementsByTagName("id")[0].childNodes[0].nodeValue + "<br>";
valDiv += planets[i].getElementsByTagName("name")[0].childNodes[0].nodeValue + "<br>";
document.getElementById("planetenID").innerHTML += valDiv + "<br>";
// Create button with a value and pass in this object for later reference use (valButton.object=this)
valButton = document.createElement("input");
// valButton.setAttribute("planeetID", planets[i].getElementsByTagName("id")[0].childNodes[0].nodeValue);
valButton.setAttribute("value", 'Meer info');
valButton.setAttribute("type", 'button');
valButton.id = (i + 1);
valButton.object = this;
//
// Here is the problem i cant get fixed
//
//valButton.onclick = function(){ showinfo(); }
valButton.addEventListener('click', showinfo);
// Place the button on screen
document.getElementById("planetenID").appendChild(valButton);
}
}
// simple function to check if it works
function showinfo() {
console.log(this.object);
console.log(this.id);
}
The trouble is this line:
document.getElementById("planetenID").innerHTML += valDiv + "<br>";
When you set innerHTML the content currently in there gets destroyed and replaced with the new html, meaning all your old buttons are now destroyed and new ones are created. The previously attached event listeners do not get attached to the new buttons.
Instead simply create a div/span or whatever container would best help, add your planet text or whatever to it and then use appendChild
valDiv = document.createElement("div");
var id = planets[i].getElementsByTagName("id")[0].childNodes[0].nodeValue;
var name = planets[i].getElementsByTagName("name")[0].childNodes[0].nodeValue;
valDiv.innerHTML = id+"<br>"+name+"<br>";
document.getElementById("planetenID").appendChild(valDiv);
You could also use insertAdjacentHTML
var id = planets[i].getElementsByTagName("id")[0].childNodes[0].nodeValue;
var name = planets[i].getElementsByTagName("name")[0].childNodes[0].nodeValue;
valDiv = id+"<br>"+name+"<br>";
document.getElementById("planetenID").insertAdjacentHTML("beforeend",valDiv);
function updatePlaneten() {
var valDiv, planets, valButton, textNode;
// Get xml files
planets = this.responseXML.getElementsByTagName("planeet");
// loop through the <planet> tags
for (var i = 0; i < planets.length; i++) {
(function(num){
valDiv = document.createElement("div");
// Get the id and the name from the xml info in current <planet> tag
var id = planets[num].getElementsByTagName("id")[0].childNodes[0].nodeValue + "<br>";
var name = planets[num].getElementsByTagName("name")[0].childNodes[0].nodeValue + "<br>";
valDiv.innerHTML = id+"<br>"+name+"<br>";
document.getElementById("planetenID").appendChild(valDiv);
// Create button with a value and pass in this object for later reference use (valButton.object=this)
valButton = document.createElement("input");
// valButton.setAttribute("planeetID", planets[i].getElementsByTagName("id")[0].childNodes[0].nodeValue);
valButton.setAttribute("value", 'Meer info');
valButton.setAttribute("type", 'button');
valButton.id = (num + 1);
valButton.object = this;
// FIX: PASS showinfo TO AN ANONYMOUS FUNCTION CONTAINING THE OBJECT
valButton.addEventListener('click', function(){
showinfo(valButton);
});
// Place the button on screen
document.getElementById("planetenID").appendChild(valButton);
}(i));
}
}
// simple function to check if it works
function showinfo(valButton) {
console.log(valButton.object);
console.log(valButton.id);
}

Change existing DIV from a CLASS to an ID

Is this possible? Or is there a way to tack on and ID to an existing div?
This is my code. I can't get the code to work using classes, but I found when I used getElementById and changed the div to an ID, that it did. But I have a ton of already posted stuff so it would take forever to go through all those posts and change it manually to an ID.
Can I incorperate JQuery in this and still have it work? I tried that with something I stumbled across but it didn't work so I removed it. I don't remember what it is now though. :S
<div id="imdb" class="imdb">tt2382396</div>
<script>
function imdbdiv() {
var imdbmain = "http://www.imdb.com/title/";
var end = "/#overview-top";
var idnum = document.getElementsByClassName("imdb");
var newdiv = document.createElement("div");
var done = "<a href='" + imdbmain + idnum + end + "'>IMDB</a>";
newdiv.innerHTML = done;
document.body.appendChild(newdiv);
}
window.onload = imdbdiv();
</script>
Can anyone help. I cannot for the life of me figure this out.
JsFiddle
Your problem was, you were appending the collection returned by document.getElementsByClassName instead of looping through the elements in the collection. You can verify this by looking at the href property of the link in your jsFiddle. You must loop through the values, then access the data in their innerHTML property.
You can use document.querySelectorAll to get a list of all elements matching a certain CSS selector, in your case .imdb. This is more flexible, in case you want to select elements with more than one class. I've pasted the code from the updated jsFiddle below.
function imdbdiv() {
var imdbMain = "http://www.imdb.com/title/",
end = "/#overview-top",
imdbValueDivs = document.querySelectorAll('.imdb'),
length = imdbValueDivs.length,
// Iterator values
i,
newDiv,
newLink;
// Loop over all of your link value containers
for (i = 0; i < length; i++) {
// Create the container
newDiv = document.createElement('div');
// Create the new link
newLink = document.createElement('a');
newLink.href = imdbMain + imdbValueDivs[i].innerHTML + end;
newLink.innerHTML = "My favorite film";
// Add the link to the container,
// and add the container to the body
newDiv.appendChild(newLink);
document.body.appendChild(newDiv);
}
}
window.onload = imdbdiv();
If you have many such divs on your page, then it could be like this:
<div class="imdb">tt2382396</div>
<div class="imdb">tt2382396</div>
<div class="imdb">tt2382396</div>
<script>
function imdbdiv() {
var imdbmain = "http://www.imdb.com/title/";
var end = "/#overview-top";
var idnums = document.getElementsByClassName("imdb");
for (var i =0; i < idnums.length; i++) {
var newdiv = document.createElement("div");
var done = "<a href='" + imdbmain + idnums[i].innerText + end + "'>IMDB</a>";
newdiv.innerHTML = done;
document.body.appendChild(newdiv);
}
}
window.onload = imdbdiv();
</script>
See jsfiddle
UPDATE:
The following string was incorrect:
window.onload = imdbdiv;
Okay, so your question is a little bit unclear.
The way I understood your question is that you have a whole bunch of div elements with class attribute and what you want is to simply copy the class value to the id attribute of the div elements.
If that's correct then try something like this with jquery:
<script>
$(document).ready(function(){
$(".imdb").each(function(imdbDiv){
var classValue = imdbDiv.attr("class");
imdbDiv.attr("id", classValue);
});
});
</script>

Inserting CSS-linked HTML in HTML page code via JS

I do not have access to the HTML of the pages (they are program-built dynamically).
I do have access to the JS page it is linked to.
For example I can do somethin like this and it works:
window.onload=function(){
var output = document.getElementById('main_co');
var i=1;
var val="";
while(i<=1)
{ if(!document.getElementById('timedrpact01'+i))
{
var ele = document.createElement("div"); ele.setAttribute("id","timedrpact01"+i);
ele.setAttribute("class","inner");
ele.innerHTML=" Hi there!" ;
output.appendChild(ele);
I would like to use this basis insert a button that would allow to switch from one CSS set (there are several files invoked) to another _another path.
Many thanks
The external stylesheets are referenced using link, as in:
<link rel="stylesheet" href="http://example.com/path-to-css">
So, get hold of the appropriate link element using:
var css = document.getElementsByTagName("link")[0];
Here, we got hold of the first link available by specifying the [0] index.
Then, overwrite the href attribute to point it to the new path.
css.setAttribute("href", "http://example.com/path-to-css");
window.onload=function(){
var output = document.getElementById('main_co');
var i=1;
var val="";
//switch all the href's to another path
var switchStyleSheet = function() {
var links = document.getElementsByTagName("link");
for(var i=0; lkC = links.length; i < lkC; i++)
links[0].href = links[0].href.replace('path_to_file', '_path_to_file');
};
while(i<=1) //while is not required here, if i is 1
{
if(!document.getElementById('timedrpact01'+i)) {
var ele = document.createElement("div"); ele.setAttribute("id","timedrpact01"+i);
ele.setAttribute("class","inner");
ele.innerHTML=" Hi there!" ;
var button = document.createElement('button');
if(button.addEventListener) {
button.addEventListener('click', switchStyleSheet);
}
else {
button.attachEvent('click', switchStyleSheet);
}
output.appendChild(button);
output.appendChild(ele);
}
}
}

How can I reference an element after I have appended it using javascript not jquery

I am doing some basic javascripting and am creating a 3 column table created by javascript sourced from an xml. The table is created by appending all the data in rows via javascript.
The first column has an input checkbox, created via javascript, that if ticked fetches a price from the third column on that row and adds all the prices of the rows selected to give a price total.
The problem I am having is I don't seem to be able to reference the appended information to obtain the information in the related price column (third column).
I have attached both the function I am using to create the table which is working and the function I am using to try and add it up which isnt working.
I found the following two articles Getting access to a jquery element that was just appended to the DOM and How do I refer to an appended item in jQuery? but I am using only javascript not jquery and would like a javascript only solution if possible.
Can you help? - its just the calculateBill function that isn't working as expected.
Thank you in advance
function addSection() {
var section = xmlDoc.getElementsByTagName("section");
for (i=0; i < section.length; i++) {
var sectionName = section[i].getAttribute("name");
var td = document.createElement("td");
td.setAttribute("colspan", "3");
td.setAttribute("class","level");
td.appendChild(document.createTextNode(sectionName));
var tr = document.createElement("tr");
tr.appendChild(td);
tbody.appendChild(tr);
var server = section.item(i).getElementsByTagName("server");
for (j=0; j < server.length; j++) {
var createTR = document.createElement("tr");
var createTD = document.createElement("td");
var createInput = document.createElement("input");
createInput.setAttribute("type", "checkbox");
createInput.setAttribute("id", "checkInput");
createTD.appendChild(createInput);
createTR.appendChild(createTD);
var item = server[j].getElementsByTagName("item")[0].innerHTML;
var createTD2 = document.createElement("td");
var createText = document.createTextNode(item);
createTD2.appendChild(createText);
createTR.appendChild(createTD2);
var price = server[j].getElementsByTagName("price")[0].innerHTML;
var createTD3 = document.createElement("td");
var createText2 = document.createTextNode("£" + price);
createTD3.appendChild(createText2);
createTR.appendChild(createTD3);
tbody.appendChild(createTR);
}
}
}
onload = addSection();
function calculateBill() {
var finalBill = 0.0;
var checkBox = document.getElementById("checkInput");
for (i=0; i < checkBox.length; i++) {
if (checkBox[i].checked) {
var parentTR = checkBox[i].parentNode;
var priceTD = parentTR.getElementsByTagName('td')[2];
finalBill += parseFloat(priceTD.firstChild.data);
}
}
return Math.round(finalBill*100.0)/100.0;
}
var button = document.getElementById("button");
button.onClick=document.forms[0].textTotal.value=calculateBill();
When you do x.appendChild(y), y is the DOM node that you are appending. You can reference it via javascript either before or after appending it. You don't have to find it again if you just hang on to the DOM reference.
So, in this piece of code:
var createInput = document.createElement("input");
createInput.setAttribute("type", "checkbox");
createInput.setAttribute("id", "checkInput");
createTD.appendChild(createInput);
createInput is the input element. You can reference it with javascript at any time, either before or after you've inserted it in the DOM.
In this piece of code:
var price = server[j].getElementsByTagName("price")[0].innerHTML;
var createTD3 = document.createElement("td");
var createText2 = document.createTextNode("£" + price);
createTD3.appendChild(createText2);
createTR.appendChild(createTD3);
tbody.appendChild(createTR);
You're creating a <td> element and putting a price into it. createTD3 is that particular <td> element.
If you want to be able to find that element sometime in the future long after the block of code has run, then I'd suggest you give it an identifying id or class name such that you can use some sort of DOM query to find it again. For example, you could put a class name on it "price" and then be able to find it again later:
var price = server[j].getElementsByTagName("price")[0].innerHTML;
var createTD3 = document.createElement("td");
createTD3.className = "price";
var createText2 = document.createTextNode("£" + price);
createTD3.appendChild(createText2);
createTR.appendChild(createTD3);
tbody.appendChild(createTR);
Then, you could find all the price elements again with:
tbody.querySelectorAll(".price");
Assuming tbody is the table where you put all these elements (since that's what you're using in your enclosed code). If the table itself had an id on it like id="mainData", then you could simply use
document.querySelectorAll("#mainData .price")
to get all the price elements.
FYI, here's a handy function that goes up the DOM tree starting from any node and finds the first node that is of a particular tag type:
function findParent(node, tag) {
tag = tag.upperCase();
while (node && node.tagName !== tag) {
node = node.parentNode;
}
return node;
}
// example usage:
var row, priceElement, price;
var checkboxes = document.querySelectorAll(".checkInput");
for (var i = 0; i < checkboxes.length; i++) {
// go up to the parent chain to find out row
row = findParent(checkboxes[i], "tr");
// look in this row for the price
priceElement = row.querySelectorAll(".price")[0];
// parse the price out of the price element
price = parseFloat(priceElement.innerHTML.replace(/^[^\d\.]+/, ""));
// do something here with the price
}

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