I'm trying to retrieve all the elements by class name by using the method getElementsByClassName (no jQuery). Console.log shows the array of the elements, but when I try to get the length of the array, it returns 0.
Saw a previous post with a similar problem that provided a solution of making sure that the element exists. I took this into consideration and fire the function after DOMcreation.
What is going on here?
document.addEventListener("DOMContentLoaded", function(){
// Load current todo items from db
loadTodoItems();
var submitBtn = document.getElementById('submit-btn');
submitBtn.addEventListener('click', addItem);
var removeButton = document.getElementsByClassName("remove-btn");
console.log(removeButton);
console.log(removeButton.length);
}, false)
Another issue to note, is that I am noticing that in chrome Dev Tools when I look at the head tag, I'm seeing that some sort of angular code is being loaded in a script tag in the head, while the content that should be in my head tag are being loaded in the body. I am not using angular for my app.
Edit. Here is my HTML. It is in Jade:
Layout.jade:
doctype html
html(lang='en')
head
meta(charset="utf-8")
title To Do List
link(rel="stylesheet" href="main.css")
body
block content
script(src="main.js")
index.jade:
extends layout
block content
div.container
h1 Get-Er-Done!
form#todo-form(role="form" method="POST" action="/todo")
div.form-group
label(for="addToDo") Add To-Do item:
input#todoItemText.form-control(type="text")
button(type="submit")#submit-btn.btn.btn-default Add
ul#todo-list
Edit. The remove button is for the new todo item. This is called every time the user clicks add to post the new item.
function renderItems(items){
// Before rendering todo-items, clear the existing items in the list
var list = document.getElementById('todo-list');
while(list.hasChildNodes()){
list.removeChild(list.lastChild);
}
// Loop through items
for (var i = 0; i < items.length; i++) {
var el = document.createElement("li");
var removeBtn = document.createElement('button');
var btnText = document.createTextNode('Done');
removeBtn.appendChild(btnText);
removeBtn.className = 'remove-btn';
var newItemText = document.createTextNode(items[i].item);
el.appendChild(newItemText); // Add new content to new div
el.appendChild(removeBtn);
// To-Do list to append to
list.appendChild(el);
}
}
Length is 0 because when you run it there's no element with class remove-btn. You can see the items in the console because getElementsByClassName returns a live HTMLCollection, which is updated when new elements are added.
The problem is that you create the elements with that class in renderItems, which runs after you run getElementsByClassName.
You can fix it using
function renderItems(items){
var list = document.getElementById('todo-list');
while(list.hasChildNodes()){/* ... */}
for (var i = 0; i < items.length; i++) {/* ... */}
// Load current todo items from db
loadTodoItems();
var submitBtn = document.getElementById('submit-btn');
submitBtn.addEventListener('click', addItem);
var removeButton = document.getElementsByClassName("remove-btn");
console.log(removeButton);
console.log(removeButton.length);
}
Related
I am trying to create a li item and append the fragment dynamically to ul using only javascript. it is part of a project. I have written a code but every time the console is giving me a different error, the last one was "document is not defined". I need to know what I am doing wrong.
the errors I get on the console was:
1- getAttribute is not a function.
2-document is not defined
3- appendChild is not a function.
4- cannot appendChild to null
const nav_list= document.querySelectorAll("section");
const myUl = document.getElementById("navbar__list");
// create fragment
let nav_fragment = document.createDocumentFragment();
function addItemList(){
for (let i = 0; i < nav_list.length; i++){
let newText= nav_list[i].getAttribute("data-nav");
// creat new li
let newLi= documnet.creatElement("li");
// create new link
let newLink= document.createElement ("a");
// create text node
let textNode = document.creatTextNode ("newText");
// add eventListener
newLink.addEventListener("click", function(){
section[i].scrollIntoView({behavior : "smooth"});
});
newLink.appendChild(textNode);
newLi.appendChild(newLink);
nav_fragment.appendChild(newLi);
}
myUl.appendChild(nav_fragment);
}
// Build menu
addItemList();
** edit: the script tag is added at the bottom of the html right before the .
To be sure that the document is loaded, add your script in a function called when the DOMContentLoaded event is triggered.
window.addEventListener('DOMContentLoaded', (event) => {
... your code here
});
I deleted the button part in my script but not even the first part of my function is working where I type in input box and suppose to be added to the ...I don't understand why. When I run the code without the buttons code which is titled " //BUTTON creation " I get no error but no item is being added to the list. So I have two problems Items aren't being added to my list and aren't displaying and also if I include the button part its saying an error "list.appendChild is not a function"
<input type="text" placeholder="Enter an Activity" id="textItem">
<img src="images/add-button.png" id="addButton">
<div id="container">
<ul class="ToDo">
<!--
<li>
This is an item
<div id="buttons">
<button ></button>
<img src="images/remove-icon.png"id="remove">
<button id="complete"></button>
<img src="images/complete-icon.jpg" id="complete">
</div>
</li>
!-->
</ul>
</div>
<script type="text/javascript">
//Remove and complete icons
var remove = document.createElement('img').src =
"images/remove-icon.png";
var complete = document.createElement('img').src = "images/complete-icon.jpg";
//user clicks add button
//if there is text in the item field we grab the item into var text
document.getElementById("addButton").onclick = function()
{
//value item is the text entered by user
var value = document.getElementById("textItem").value;
//checks if there is a value typed
if(value)
{
addItem(value);
}
//adds a new item to the ToDo list
function addItem(text)
{
var list = document.getElementsByClassName("ToDo");
//created a varibale called item that will create a list item everytime this function is called
var item = document.createElement("li");
//this will add to the innerText of the <li> text
item.innerText = text;
//BUTTON creation
var buttons = document.createElement('div');
buttons.classList.add('buttons');
var remove = document.createElement('buttons');
buttons.classList.add('remove');
remove.innerHTML = remove;
var complete = document.createElement('buttons');
buttons.classList.add('complete');
complete.innerHTML = complete;
buttons.appendChild(remove);
buttons.appendChild(complete);
list.appendChild(buttons);
list.appendChild(item);
}
}
</script>
The problem is in the line:
var list = document.getElementsByClassName("ToDo");
list.appendChild(item);
The line var list = document.getElementsByClassName("ToDo"); will provide a collection, notice the plural name in the api.
You need to access it using :
list[0].appendChild(item);
There are other problems too in the code but hopefully this gets you going!
There are a couple of issues in your code that need to be addressed to get it to work properly.
1) You are creating your image elements and then setting the variables to the src name of that image and not the image object itself. When you use that reference later on, you are only getting the image url and not the element itself. Change var remove = document.createElement('img').src = "images/remove-icon.png" to this:
var removeImg = document.createElement('img')
removeImg.src = "images/remove-icon.png";
2) As #Pankaj Shukla noted, inside the onclick function, getElementsByClassName returns an array, you will need to address the first item of this array to add your elements. Change var list = document.getElementsByClassName("ToDo") to this:
var list = document.getElementsByClassName("ToDo")[0];
3) For your buttons, you are trying to creating them using: var remove = document.createElement('buttons'). This is invalid, buttons is an not the correct element name, its button. Additionally, you are re-declaring the variables remove and complete as button objects, so within the onclick function it reference these buttons, not the images you defined earlier. So when you assign the innerHTML to remove and complete, you are assigning the buttons innerHTML to itself. The solution is to change the image variables to something different.
4) Finally, also relating to the buttons, you are assigning the innnerHTML to an image object, that's incorrect. You can either insert the html text of the img directly, or append the image object as a child of the button, similar to how the button is a child of the div.
The updated code with all these changes looks like this:
//Remove and complete icons
var removeImg = document.createElement('img');
removeImg.src = "images/remove-icon.png";
var completeImg = document.createElement('img');
completeImg.src = "images/complete-icon.jpg";
//user clicks add button
//if there is text in the item field we grab the item into var text
document.getElementById("addButton").onclick = function() {
//value item is the text entered by user
var value = document.getElementById("textItem").value;
//checks if there is a value typed
if (value) {
addItem(value);
}
//adds a new item to the ToDo list
function addItem(text) {
var list = document.getElementsByClassName("ToDo")[0];
//created a varibale called item that will create a list item everytime this function is called
var item = document.createElement("li");
//this will add to the innerText of the <li> text
item.innerText = text;
//BUTTON creation
var buttons = document.createElement('div');
buttons.classList.add('buttons');
var remove = document.createElement('button');
remove.classList.add('remove');
remove.appendChild(removeImg);
var complete = document.createElement('button');
complete.classList.add('complete');
complete.appendChild(completeImg);
buttons.appendChild(remove);
buttons.appendChild(complete);
list.appendChild(buttons);
list.appendChild(item);
}
}
I'm working on an Ionic-app.
On one of my pages i'm adding elements dynamically to a div-element.
The elements are added but i can't see them on the page.
Just after clicking F5 and running the controller-code again i can see them.
Here's the code for adding the elements:
if ($scope.eigenschaften != null) {
//TODO Eigenschaften in Loop durchgehen und auf panel_dynamic Controls erzeugen
var panel_dynamic = document.getElementById('panel_dynamic');
if (panel_dynamic.hasChildNodes()) {
panel_dynamic.removeChild(panel_dynamic.childNodes[0]);
}
var content = document.createElement('div');
for (n = 0; n <= $scope.eigenschaften.length - 1; n++) {
// Creates a new div with controls
var line = document.createElement('div');
var para = document.createElement('p');
// Creates a div-row
var div_row = document.createElement('div');
div_row.setAttribute('class', 'row');
// Creates a div-col with label
var div_col_label = document.createElement('div');
div_col_label.setAttribute('class', 'col');
div_col_label.appendChild(CreateLabel('font-size:16px;font-weight:bold;', $scope.eigenschaften[n].name));
div_row.appendChild(div_col_label);
// Creates a div-col with control
var div_col_control = document.createElement('div');
div_col_control.setAttribute('class', 'col');
div_col_control.appendChild(CreateTextbox());
div_row.appendChild(div_col_control);
// Adds the div-row to the para
para.appendChild(div_row);
// Adds the new para to the line
line.appendChild(para);
// Adds the new line to the content
content.appendChild(line);
}
// Adds the content-div to panel_dynamic
panel_dynamic.appendChild(content);
}
"eigenschaften" is an array with the data.
It looks like you aren't triggering change detection. You should add the elements using an ng-repeat in your template that's bound to an array or some other iterable on the model instead. Then everytime you add something new to the iterable, it will get added in the view.
Unfortunately i used the id for my container-div "panel_dynamic" even in another template. And JavaScript was getting the other div by getElementById. Now i have changed the ids and it works.
I am attempting to populate a list with href links via javascript.
Here is an example of the html I would like to create:
<li> Complete blood count</li>
Where "#modal-one" displays a pop up.
I have used the following and several other iterations to try and create this dynamically:
<script>
var listItem = [];
function createTestList() {
var tests = results.tests; //an array to tests to populate list
var i;
var j;
for (i = 0; i < tests.length ; i++ ){
listItem[i] = document.createElement("li");
var node = document.createTextNode(tests[i].name);
listItem[i].appendChild(node);
listItem[i].setAttribute("href", "#modal-one");
addOnClick(i);
//var element = document.getElementById("div1");
//element.appendChild(listItem[i]);
document.body.appendChild(listItem[i]);
console.log(listItem[i]);
};
};
function addOnClick(j) { //this is separate to handle the closure issue
listItem[j].onclick = function() {loadModal(j)};
};
</script>
However, this code (and several others) produce:
<li href='#modal-one'>Complete Blood Count</li> //note missing <a>...</a>
It appears there are several ways to achieve this, but nothing seems to work for me...
You are never actually adding in an anchor tag. You are creating a list-item (li), but you are adding an href to that list-item rather than adding an anchor node to it with that href. As such, the browser just thinks you have a list-item with an href attribute.
Consider using the following instead:
<script>
var listItem = [];
function createTestList() {
var tests = results.tests; //an array to tests to populate list
var i;
var j; // Never actually used in function. Consider omitting
for (i = 0; i < tests.length ; i++ ){
// create the list item
listItem[i] = document.createElement("li");
// Create the anchor with text
var anchor = document.createElement("a");
var node = document.createTextNode(tests[i].name);
anchor.appendChild(node);
anchor.setAttribute("href", "#modal-one");
// Set the onclick action
addOnClick(i, anchor);
// Add the anchor to the page
listItem[i].appendChild(anchor);
document.body.appendChild(listItem[i]);
console.log(listItem[i]);
};
};
// Modified "addOnClick" to include the anchor that needs the onclick
function addOnClick(j, anch) { //this is separate to handle the closure issue
anch.onclick = function() {loadModal(j)};
};
</script>
A couple things to note:
I have modified your addOnClick() function because it is the anchor element that needs the onclick, not the list item.
I have added in the creation of an anchor element rather than simply creating a list item and adding the href to that.
I do not see creating a element, change code to:
var aNode=document.createElement("a");
aNode.innerText=tests[i].name;
aNode.setAttribute("href", "#modal-one");
listItem[i].appendChild(aNode);
You can change also click method, to use it on a not on li
function addOnClick(j) {
listItem[j].querySelector("a").addEventListener("click",function(e) {
e.preventDefault();//this prevent for going to hash in href
loadModal(j);
});
};
Okay. I missed the anchor tag. My bad...
Spencer's answer came close, but I had to make few changes to get it work in my instance.
The final working code (and honestly I am not sure why it works) is:
<script>
var listItem = [];
function createTestList() {
var tests = results.tests;
var i;
//var j;
for (i = 0; i < tests.length ; i++ ){
// create the list item
listItem[i] = document.createElement("li");
// Create the anchor with text
var anchor = document.createElement("a");
anchor.setAttribute("href", "#modal-one");
var node = document.createTextNode(tests[i].name);
anchor.appendChild(node);
// Set the onclick action
addOnClick(i);
// Add the anchor to the page
listItem[i].appendChild(anchor);
document.getElementById("demo").appendChild(listItem[i]); //added the list to a separate <div> rather than body. It works fine like this.
console.log(listItem[i]);
};
};
function addOnClick(j) { //this is separate to handle the closure issue
//didn't need the additional code beyond this
listItem[j].onclick = function() {loadModal(j)};
};
</script>
Thanks to all and Spencer thanks for the thoroughly commented code. It helps!!!
I have been using jQuery for a short period of time & currently I am working with a website where user will log in and then jQuery will get the data from the server and append it to the existing html code. I have searched a lot in stackoverflow for this and my current code is actually the summary of what I have learnt fro here. I have tried with the load function but later I saw it has been deprecated.
My intention is to add the data after the file is loaded or by any how enable users to see the data. I also need to add id so that I can get to add certain behavior for later. Both of this functions can be accessed from both html file (index.html and profile.html > profile.html will be loaded after login)
My code is given below.
function changePage(mainArray, length)
{
location.href="temp.html";
addData(mainArray, length);
}
$(function() {
function addData(mainArray, length)
{
alert("entry 1");
for(i = 0; i < length; i++)
{
var id1 = "h3"+i;
var id2 = "p"+i;
var newHeader= $('<h3></h3>'); //create a new h3
$(newHeader).attr('id', id1); //set the id attribute of newHeader
$(newHeader.html(mainArray["title"][i])); //set the innerHtml of the header
var newPara = $('<p></p>'); //create a new p
$(newPara).attr('id', id2); //set p id attribute
$(newPara).html(mainArray["desc"][i]); //add descr
$('#div1').append(newHeader);
$('#div1').append(newPara); //add them to dom.
}
$("h3").text("View Summary");
console.log("does it work?");
}
});
Your question could be a bit more descriptive, but my understanding is that you're performing an asynchronous request with jquery, then appending some elements to the DOM containing some part of the response. You reference 'adding data after file is loaded', that would probably mean you need to put your code inside of the basic document ready function of jquery:
$( document ).ready(function() {
//your code here
});
-shorthand version
$(function() {
//your code here
});
Now, the meat of your question is adding the elements after we get the data. Try something closer to this:
function addData(mainArray, length)
{
for(i = 0; i < length; i++)
{
var id1 = "h3"+i;
var id2 = "p"+i;
var newHeader= $('<h3></h3>'); //create a new h3
$(newHeader).attr('id', id1); //set the id attribute of newHeader
$(newHeader.html(mainArray["title"][i]); //set the innerHtml of the header
var newPara = $('<p></p>'); //create a new p
$(newPara).attr('id', id2); //set p id attribute
$(newPara).html(mainArray["desc"][i]); //add descr
$('#div1').append(newHeader);$('#div1').append(newPara); //add them to dom.
}
$("h3").text("View Summary");
console.log("does it work?");
}