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.
Related
I'm trying to create a chrome extension. I had a problem with the affectation of event for the new element that i append to the dom of site with content. Js
If I add an event to an element' 'for example class' exist already in the page, it works correctly. Just for my new appended element((in the code iadded a button ,the event is just an alert to test))
function tst() {
myclass = $("._3hg-._42ft");
myclass = myclass.not(".supp");
myclass.addClass("supp");
var patt = /https:\/\/(.)*\.facebook\.com\/(.)*\/(posts|photos|videos)\/(\w|\.|\d)*/g;
for (i = 0; i < myclass.length; i++) {
result = patt.exec(myclass[i]);
myclass.append('<button class="fact" id=' + result[0] + ' style="position: absolute;">fact</button>');
};
/* this is a simple event*/
/***********************/
$(".fact").on('click', function() {
alert("no event work ");
});
Making somewhat broad assumption here in my answer that it is JavaScript/jQuery related and is NOT an extension...or is so still in that context.
You need to attach the event to the container here perhaps for the dynamically created elements. Lots of global stuff, suggested to not do that, updated there.
Appends a lot of buttons perhaps? might need to only hit DOM once but left as-is in this isolated function.
function tst() {
let myclass = $("._3hg-._42ft")
.not(".supp");
myclass.addClass("supp");
//let result = {};
var patt = /https:\/\/(.)*\.facebook\.com\/(.)*\/(posts|photos|videos)\/(\w|\.|\d)*/g;
var i = 0; //avoid global
for (i; i < myclass.length; i++) {
// broad assumption of the returned value from patt.exec() here
// not even sure why it needs an id, have a class, use for css
let result = patt.exec(myclass[i]);
myclass.append('<button class="fact" id="' + result[0] + '">fact</button>');
}
/* attache event to pre-existing element */
/***********************/
myclass.on('click', ".fact", function() {
alert("event works");
});
}
button.fact {
position: absolute;
}
I have an array of audio files that I want to play through whenever I click a button. If I click said button, it will play the next audio file in the array. Also, if audio is currently playing when the user clicks again, the current track is reset and the next song plays.
Trying to figure out why I can't cycle through the array I currently have.
var song1 = $("#sound-1");
var song2 = $("#sound-2");
var song3 = $("#sound-3");
var song4 = $("#sound-4");
var song5 = $("#sound-5");
var song6 = $("#sound-6");
var song7 = $("#sound-7");
var song8 = $("#sound-8");
var audioArray = [ song1, song2, song3, song4, song5, song6, song7, song8 ];
$(".click").click(function(){
var i=0;
if (i< audioArray.length){
audioArray[i].trigger('play');
i++;
} else if ( i>audioArray.length){
i = 0;
audioArray[i].trigger('play');
};
});
Updated answer:
Since you are using the native HTML5 interface, there is a pause event that can be triggered as well. Unfortunately, there is no stop event that would reset the time, however we can set it to 0 manually using the currentTime property.
var i=0;
var lastPlayedFile = null;
$(".click").click(function(){
if(lastPlayedFile !== null) {
lastPlayedFile[0].currentTime = 0; // [0] because we need a native DOM element, not a jQuery-wrapped one
lastPlayedFile.trigger('pause');
}
if (i< audioArray.length){
lastPlayedFile = audioArray[i];
audioArray[i].trigger('play');
i++;
} else if (i>=audioArray.length){ // there was a missing '=' in this condition to work properly
i = 0;
lastPlayedFile = audioArray[0];
audioArray[i].trigger('play');
};
});
Here is a fiddle I created. I've tested it in Chrome and it works flawlessly.
I suggest looking at the audio tag reference to see what more you can achieve by manipulating the native DOM audio element.
Original answer:
Move declaration of i outside the click handler.
var i=0;
$(".click").click(function(){
if (i< audioArray.length){
audioArray[i].trigger('play');
i++;
} else if ( i>audioArray.length){
i = 0;
audioArray[i].trigger('play');
};
});
You were resetting it's value to 0 each time user clicked the button.
I've created a script that attaches an event listener to a collection of pictures by default. When the elements are clicked, the listener swaps out for another event that changes the image source and pushes the id of the element to an array, and that reverses if you click on the swapped image (the source changes back and the last element in the array is removed). There is a button to "clear" all of the images by setting the default source and resetting the event listener, but it doesn't fire reliably and sometimes fires with a delay, causing only the last element in a series to be collected.
TL;DR: An event fires very unreliably for no discernible reason, and I'd love to know why this is happening and how I should fix it. The JSFiddle and published version are available below.
I've uploaded the current version here, and you can trip the error by selecting multiple tables, pressing "Cancel", and selecting those buttons again. Normally the error starts on the second or third pass.
I've also got a fiddle.
The layout will be a bit wacky on desktops and laptops since it was designed for phone screens, but you'll be able to see the issue and inspect the code so that shouldn't be a problem.
Code blocks:
Unset all the selected tables:
function tableClear() {
//alert(document.getElementsByClassName('eatPlace')[tableResEnum].src);
//numResTables = document.getElementsByClassName('eatPlace').src.length;
tableArrayLength = tableArray.length - 1;
for (tableResEnum = 0; tableResEnum <= tableArrayLength; tableResEnum += 1) {
tableSrces = tableArray[tableResEnum].src;
//alert(tableSrcTapped);
if (tableSrces === tableSrcTapped) {
tableArray[tableResEnum].removeEventListener('click', tableUntap);
tableArray[tableResEnum].addEventListener('click', tableTap);
tableArray[tableResEnum].src = window.location + 'resources/tableBase.svg';
} /*else if () {
}*/
}
resTableArray.splice(0, resTableArray.length);
}
Set/Unset a particular table:
tableUntap = function () {
$(this).unbind('click', tableUntap);
$(this).bind('click', tableTap);
this.setAttribute('src', 'resources/tableBase.svg');
resTableArray.shift(this);
};
tableTap = function () {
$(this).unbind('click', tableTap);
$(this).bind('click', tableUntap);
this.setAttribute('src', 'resources/tableTapped.svg');
resTableArray.push($(this).attr('id'));
};
Convert the elements within the 'eatPlace' class to an array:
$('.eatPlace').bind('click', tableTap);
tableList = document.getElementsByClassName('eatPlace');
tableArray = Array.prototype.slice.call(tableList);
Table instantiation:
for (tableEnum = 1; tableEnum <= tableNum; tableEnum += 1) {
tableImg = document.createElement('IMG');
tableImg.setAttribute('src', 'resources/tableBase.svg');
tableImg.setAttribute('id', 'table' + tableEnum);
tableImg.setAttribute('class', 'eatPlace');
tableImg.setAttribute('width', '15%');
tableImg.setAttribute('height', '15%');
$('#tableBox').append(tableImg, tableEnum);
if (tableEnum % 4 === 0) {
$('#tableBox').append("\n");
}
if (tableEnum === tableNum) {
$('#tableBox').append("<div id='subbles' class='ajaxButton'>Next</div>");
$('#tableBox').append("<div id='cazzles' class='ajaxButton'>Cancel</div>");
}
}
First mistake is in tapping and untapping tables.
When you push a Table to your array, your pushing its ID.
resTableArray.push($(this).attr('id'));
It will add id's of elements, depending on the order of user clicking the tables.
While untapping its always removing the first table.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/shift
resTableArray.shift(this);
So, when user clicks tables 1, 2, 3. And unclicks 3, the shift will remove table 1.
Lets fix this by removing untapped table
tableUntap = function () {
$(this).unbind('click', tableUntap);
$(this).bind('click', tableTap);
this.setAttribute('src', 'http://imgur.com/a7J8OJ5.png');
var elementID = $(this).attr('id');
var elementIndex = resTableArray.indexOf(elementID);
resTableArray.splice(elementIndex, 1);
};
So you were missing some tables after untapping.
Well lets fix tableClear,
You have a array with tapped tables, but you are searching in main array.
function tableClear() {
tableLen = resTableArray.length;
for (var i = 0; i < tableLen; i++) {
var idString = "#" + resTableArray[i];
var $element = $(idString);
$element.unbind('click', tableUntap);
$element.bind('click', tableTap);
$element.attr("src", 'http://imgur.com/a7J8OJ5.png');
}
resTableArray = [];
}
Im searching only tapped tables, and then just untap them and remove handlers.
fiddle: http://jsfiddle.net/r9ewnxzs/
Your mistake was to wrongly remove at untapping elements.
I hope it's not a problem to post much specific code here, but I figure it will be better explained if everyone can just see it, so I will give you my code and then I will explain my problem.
My code:
function addBeGoneLinks () {
var beGoneClassElems;
var beGoneSpan;
var beGoneLink;
var beGonePrintSafe;
var spacesSpan;
//var middotSpan = document.createElement ('span');
var interactionContainer = document.getElementsByClassName('feedItemInteractionContainer');
for (var i=0; i<children.length; i++)
{
beGonePrintSafe = false;
beGoneClassElems = children[i].getElementsByClassName('beGone')
beGonePrintSafe = true;
if (beGoneClassElems.length == 0)
{
beGoneLink = document.createElement('a');
beGoneLink.href = 'javascript:void(0);';
beGoneLink.appendChild(document.createTextNode('Be Gone'));
beGoneLink.className = 'beGone';
beGoneLink.id = 'beGoneLink' + i.toString();
beGoneLink.addEventListener ("click", function() {beGone();}, false);//This line!
beGoneLink.align = 'right';
spacesSpan = document.createElement('span');
spacesSpan.innerHTML = ' - ';
if (interactionContainer[i] != undefined)
{
interactionContainer[i].appendChild(spacesSpan);
interactionContainer[i].appendChild(beGoneLink);
}
}
}
}
Here I have a function from a Greasemonkey script that I am working on. When one of the links is clicked, my aim is to have it call the function beGone() which will, among other things, remove the whole element a few parents up, thereby removing their sibling's, their parents and their parents' siblings, and one or two levels after that.
My idea was just to get the id of the link that was pressed and pass it to beGone() so that I could then get the parents using its id, but I do not know how to do that. Am I able to have the id of a link passed by the function that it calls? If not, is there any other way to do this?
I am not sure whether I am missing some really simple solution, but I haven't been able to find one rooting around the web, especially because I was unsure how I would search for this specific problem.
Try this:
beGoneLink.addEventListener("click", beGone, false);
beGone = function (evt) {
evt.target; // evt.target refers to the clicked element.
...
}
You can then use evt.target.id, evt.target.parentNode, etc.
function init()
{
alert("init()");
/**
* Adds an event listener to onclick event on the start button.
*/
xbEvent.addEventListener(document.getElementById("viewInvitation"), "click", function()
{
new Ajax().sendRequest("31260xml/invitations.xml", null, new PageMaster());
xbEvent.addEventListener(document.getElementById("declinebutton"), "click", function ()
{
declineInvitation();
});
});
ok so what I have here is a event listerner function, the case is when viewInvitation is clicked , the program will fetch my xml file and run page master function where I created my decline button with id="declinebutton", however this does not work, the error message that i get is obj=null or the program could not find id = declinebutton, why is it so? I have created it when I called page master using dom. any help will be appreciated.
function PageMaster()
{
this.contentDiv = document.getElementById("content");
}
/**
* Builds the main part of the web page based on the given XML document object
*
* #param {Object} xmlDoc the given XML document object
*/
var subjectList;
var i;
PageMaster.prototype.doIt = function(xmlDoc)
{
alert("PageMaster()");
alert("Clear page...");
this.contentDiv.innerHTML = "";
if (null != xmlDoc)
{
alert("Build page...");
//create div Post
var divPost = document.createElement("div");
divPost.className = "post";
//create h1 element
var h1Element = document.createElement("h1");
var headingText = document.createTextNode("Invitations");
h1Element.appendChild(headingText);
//insert h1 element into div post
divPost.appendChild(h1Element);
subjectList = xmlDoc.getElementsByTagName("subject");
var groupList = xmlDoc.getElementsByTagName("group");
for (i = 0; i < subjectList.length; i++) //for each subject
{
var divEntry = document.createElement("div");
divEntry.className = "entry";
var subjectNum = subjectList[i].attributes[0].nodeValue;
var subjectName = subjectList[i].attributes[1].nodeValue;
var groupId = groupList[i].attributes[0].nodeValue;
var groupName = groupList[i].attributes[1].nodeValue;
var ownerId = groupList[i].attributes[2].nodeValue;
//set up the invitation table attributes
var table=document.createElement("table");
table.width = 411;
table.border = 3;
table.borderColor = "#990000"
var input=document.createElement("p");
var inputText=document.createTextNode("You are invited to join " + groupName + "(groupId : " + groupId +")");
input.className="style11";
var blank=document.createElement("nbps");
input.appendChild(inputText);
var acceptButton=document.createElement("input");
acceptButton.type="button";
acceptButton.id="acceptbutton";
acceptButton.value="accept";
var declineButton=document.createElement("input");
declineButton.type="button";
declineButton.id="declinebutton";
declineButton.value="decline";
table.appendChild(input);
table.appendChild(acceptButton);
table.appendChild(declineButton);
divEntry.appendChild(table);
var blankSpace = document.createElement("p");
divEntry.appendChild(blankSpace);
divPost.appendChild(divEntry);
}
//insert div post into div content
this.contentDiv.appendChild(divPost);
}
};
/**function getValueOf()
{
return i;
}**/
function declineInvitation()
{
alert("decline");
}
function acceptInvitation()
{
alert("hello");
/**var pos=getValueOf();
alert(subjectList[pos].attributes[0].nodeValue);**/
}
That's my page master function, and I definitely have created the button. but it does not work.
Try calling your function like this:
window.onload=init;
The javascript runs as the page loads. At that point, the element does not yet exist in the DOM tree. You'll need to delay the script until the page has loaded.
The example you gave doesn't create the "Decline" button, as your question suggests it should. If it should, you might want to look at that.
Of course, if the button already exists, please disregard this answer.
You have a listener inside a listener. Is that right?
What about this?:
function init(){
alert("init()");
/** * Adds an event listener to onclick event on the start button. */
xbEvent.addEventListener(document.getElementById("viewInvitation"), "click", function()
{
new Ajax().sendRequest("31260xml/invitations.xml", null, new PageMaster());
}
xbEvent.addEventListener(document.getElementById("declinebutton"), "click", function ()
{
declineInvitation();
});
As far as I understand, you create button with id="declinebutton" for each entry from xml, is that right?
If yes, I'd suggest you to generate different id's for each button (for example, append line index to 'declinebutton', so you have buttons 'declinebutton0', 'declinebutton1' an so on), and assign event listener to buttons separately in the loop.