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javascript dynamically remove text

I have successfully created a button which adds text to the webpage however I do not know a viable way to remove text once this has been created. The js code I have is:
var addButtons = document.querySelectorAll('.add button');
function addText () {
var self = this;
var weekParent = self.parentNode.parentNode;
var textarea = self.parentNode.querySelector('textarea');
var value = textarea.value;
var item = document.createElement("p");
var text = document.createTextNode(value);
item.appendChild(text)
weekParent.appendChild(item);
}
function removeText() {
//document.getElementbyId(-).removeChild(-);
}
for (i = 0; i < addButtons.length; i++) {
var self = addButtons[i];
self.addEventListener("click", addText);
}
I have viewed various sources of help online including from this site however I simply cannot get any to work correctly. Thank you in advance.

Sure, it should be easy to locate the added <p> tag relative to the remove button that gets clicked.
function removeText() {
var weekParent = this.parentNode.parentNode;
var item = weekParent.querySelector("p");
weekParent.removeChild(item);
}
If there is more than 1 <p> tag inside the weekParent you will need a more specific querySelector.

Assign click to dynamically created data from database

I have created javascript in which data is fetched for dropped element and are created. The data is fetched from database using json encoding. I have assigned id to the elements but the click event for every element is not working. only the last elements id is obtained and clicked is performed on that id.
JS :
$(document).ready(function () {
var i,j=0;
var x1,x2,y1,y2;
var sf=pf;
sf=Math.round(sf);
var tmp;
var y=null;
var idiv=[];
var fty=ft;
var fd=fid;
var fetch=data;
var x = null;
var count=fetch['count'];
var i=count+1;
//document.write(count);
var rai=[];
//rai[0]='hello';
//document.write(rai[0]);
var ww=[];
var hh=[];
var xx=[];
var yy=[];
var room=[];
var roomt=[];
for(j=0;j<=count;j++)
{
rai[j]=fetch['room_id'+j];
//document.write(rai[j]);
ww[j]=fetch['width'+j];
//document.write(ww[j]);
hh[j]=fetch['height'+j];
xx[j]=fetch['x'+j];
yy[j]=fetch['y'+j];
room[j]=fetch['room'+j];
roomt[j]=fetch['roomt'+j];
//document.write(room[j]);
// alert("data"+rai+" "+ww+" "+hh+" "+xx+" "+yy);
idiv[j]=document.createElement('img')
$('#droppable').append(idiv[j]);
idiv[j].style.position="absolute";
idiv[j].style.left=(xx[j]*sf)+'px';
idiv[j].style.top=(yy[j]*sf)+'px';
idiv[j].style.width=(ww[j]*sf)+'px';
idiv[j].style.height=(hh[j]*sf)+'px';
idiv[j].style.border=1+'px';
idiv[j].id=room[j];
//y=idiv[j].attr('idd',rai[j]);
if(roomt[j]=='garden')
{
idiv[j].src="images/download.jpg";
}
else
{
idiv[j].src="images/ac.png"
}
$(idiv[j]).draggable();
//alert(y);
//y=idiv[j].id;
// alert(y);
//document.write("data"+rai[j]+" "+(ww[j]*sf)+" "+(hh[j]*sf)+" "+(xx[j]*sf)+" "+(yy[j]*sf) + room[j]);
}
//$(this).bind("click",'idiv',function(){
// alert("hello"+idiv.id);
//window.location.href="tables.php?room_id="+y;
// });
});
can anyone give idea how to bind click on each fetched element.

Ty this : add class to the element created and write a click event handler for all element having that class. See below
Add below html in Loop where you are creating idiv[j] -
idiv[j].className = "clickable";
Now write a click event handler using .on()
$(document).ready(function () {
...... your code start here
......
//loop
for(j=0;j<=count;j++)
{
...
...
}
//loop ends
... more code
....your code end here
$(document).on("click",".clickable", function(){
alert(this.id);
});
});
NOTE: Don't use bind because it is deprecated now after jQuery version 1.5

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);
}

How to interate an array with navigation menu buttons (first, previous, next, last)

Well, one more question. Since I started learning javascript short time ago, I am almost obsessed trying new things! Here it goes:
Let's say that I have an array of strings and I want to iterate on it with a navigation menu with the buttons FIRST, PREVIOUS, NEXT, LAST.
Look at this code:
var thearray = ["article1", "article2", "article3"];
var thebody = document.getElementsByTagName('body')[0];
var divcontainer = document.createElement("div");
var divpage = document.createElement("div");
function generatepage(article) {
var paragraph = document.createElement("p");
var name = document.createTextNode(thearray[article]);
paragraph.appendChild(name);
divpage.appendChild(paragraph);
}
divcontainer.appendChild(divpage);
thebody.appendChild(divcontainer);
generatepage(0); // that would be for the first article
I also figured out that generatepage(thearray.length -1)would be the call for the last article, so I have solved two buttons (before generating new content I would erase it with innerHTMLbut what I cannot think about how to do are the PREVIOUS and NEXT buttons...
Do you have any suggestion about how should I get started to make working PREVIOUS and NEXT?
I attach a JSFiddle
Thank you so much for any advice!

You can save the active page in a variable outside the function:
var page = 0;
Then you don’t need to bring any page into generatepage():
function generatepage() {
var paragraph = document.createElement("p");
var name = document.createTextNode(thearray[page]);
paragraph.appendChild(name);
divpage.appendChild(paragraph);
}
Now you can control the page from outside the function:
var next = function() {
if ( page < page.length-1 ) { page++; }
}
var prev = function() {
if ( page ) { page--; }
}
So to show the first page:
page = 0;
generatepage()
And the next:
next();
generatepage()
etc.... There are other ways too of course but this might give you an idea.

You can save a variable outside the scope of the function to memorize the current article
when you add Eventlisteners to the buttons you can call the next and previous item
but you should somehow replace the content of the div with the next one instead of appending it (i don't know a thing about manipulating dom elements)
you could try something like this:
var thearray = ["article1", "article2", "article3"];
var thebody = document.getElementsByTagName('body')[0];
var divcontainer = document.createElement("div");
var divpage = document.createElement("div");
var currentarticle
function generatepage(article) {
if(thearray[article]) {
currentarticle = article
var paragraph = document.createElement("p");
var name = document.createTextNode(thearray[article]);
paragraph.appendChild(name);
divpage.innerHTML= paragraph.innerHTML
}else {
return false
}
}
divcontainer.appendChild(divpage);
thebody.appendChild(divcontainer);
generatepage(0); // that would be for the first article
document.getElementById("next").addEventListener("click",function() {
generatepage(currentarticle + 1)
});
document.getElementById("previous").addEventListener("click",function() {
generatepage(currentarticle - 1)
});
document.getElementById("last").addEventListener("click",function() {
generatepage(thearray.length - 1)
});
document.getElementById("first").addEventListener("click",function() {
generatepage(0)
});
​
heres the Fiddle

Event handler causes many alerts

I am working on a Phonegap app, in which I access device's contacts. I then store upto 10 contacts in window.localStorage. To do so, when the user select a button, I create a div which has three elements.
An image (contact icon that represents male/female contact)
The name of the contact
Another image (represents 'add' sign to add it to window.localStorage)
I then associate an event handler, which will first check if the contact already exists in the localStorage and then proceed to add the contact. Here is the code
function checkDuplicate(somevalue)
{
for(var i=0;i<10;i++) {
if(window.localStorage.getItem(i)!=null) {
if(window.localStorage.getItem(i)==somevalue) {
navigator.notification.alert('Entry exists at Button:'+i);
return false;
}
}
}
//chosenButton is a global variable
window.localStorage.setItem(chosenButton,somevalue);
document.getElementById('contactNumberField').textContent=somevalue;
}
//Problem is with the event listener attached to span2. Please read below
function addContact(item)
{
var parentDiv = document.getElementById('thelist');
var childDiv = document.createElement('li');
var span1 = document.createElement('span');
span1.style.float='left';
span1.innerHTML = "<img src='keypad-contact.png'/>";
var span2 = document.createElement('span');
span2.style.float='right';
span2.innerHTML="<img src='keypad-addcontact.png'/>";
span2.addEventListener('click',function({checkDuplicate(item.number);},false);
childDiv.textContent=item.name;
childDiv.style.color='white';
childDiv.appendChild(span1);
childDiv.appendChild(span2);
parentDiv.appendChild(childDiv);
}
function onSuccess(contacts)
{
var objArray = new Array();
for(var i=0; i<contacts.length;i++) {
var tempObj = new Object();
tempObj['name']=contacts[i].displayName;
tempObj['number']=contacts[i].phoneNumbers[0].value;
objArray.push(tempObj);
}
objArray.sort(
function(a,b){
var nameA = a.name.toLowerCase(),nameB=b.name.toLowerCase();
if(nameA < nameB) return -1;
else if(nameA > nameB) return 1;
return 0;
});
for(var i=0; i<objArray.length;i++) addContact(objArray[i]);
}
function onDeviceReady()
{
var options = new ContactFindOptions();
options.multiple=true;
var field = ["displayName","phoneNumbers"];
navigator.contacts.find(field, onSuccess, function(){alert('NA');}, options);
}
Problem
When I try to add a contact which is already present in window.localStorage, for my first touch on span2, I get one alert. If I try to add again by touching it for the second time, I get two alerts.. and this goes on. The trouble is with the event handler associated with span2. However, I don't know how to over come this situation. How can I ensure that irrespective of how many times I press span2, I get alert only once. How to remove the event handler as soon as it is fired?
Please help.

Fixed:
The issue was not with adding event handlers dynamically. I happen to use iScroll (cubiq) for my project and that caused the trouble. Now I am not receiving multiple alerts. The trick is to declare the globlal scroller variable only once.
var scroller = null;
and then in the function
if(!scroller) scroller = new iScroll('scrollableDiv');
I hope this could be a useful tip for people who are using iScroll and struggling with multiple alerts like me.