Develop Reference

Dynamically-generated table keeps multiplying even though it's being cleared

I have a variety of fields I'm appending to a table (#dvdCollectionBody) in my function loadDvdCollectionView().
The problem: if I click the tag that calls my displayDvd() function, then hit the 'Back' button, everything works as it should. If I click the tag, calling displayDvd() a second time, then click the 'Back' button again, the table will be duplicated, indicating that rows are being appended that aren't getting cleared.
I cannot for the life of me understand why the table keeps appending itself, but only after repeating the process of clicking a 'td' tag more than once.
$(document).ready(function () {
loadDvdCollectionView();
// create on a click
createDvd();
});
function loadDvdCollectionView(){
// hide errors
$('#errorDiv').hide();
// show this view
$('#viewingTable').show();
// empty table body of any preexisting data
$('#dvdCollectionBody').empty();
$.ajax({
type: "GET",
url: "http://localhost:8080/dvds",
success:
function (data, status) { $.each(data, function (index, dvd) {
// append DVD collection to table rows in #dvdCollectionBody
var dvdRow = '<tr><td onclick="displayDvd(' + dvd.dvdId + ')">' + .......
$('#dvdCollectionBody').append(dvdRow);
});
}
// called when <td> tag is clicked
function displayDvd(dvdId){
//hide viewingTable
$('#viewingTable').hide();
// empty preexisting data
$('#releaseYearDisplay, #directorDisplay, #ratingDisplay, #notesDisplay, #dvdTitleHeader').empty();
// show table
$('#dvdDetailsDisplay, #dvdTitleHeader').show();
$.ajax({
type: "GET",
url: "http://localhost:8080/dvd/" + dvdId,
success: function (data) {
$('#dvdTitleHeader').append('
<h3>' + data.title + '</h3>'); $('#releaseYearDisplay').append('
<h3>' + data.releaseYear + '</h3>'); $('#directorDisplay').append('
<h3>' + data.director + '</h3>'); $('#ratingDisplay').append('
<h3>' + data.rating + '</h3>'); $('#notesDisplay').append('
<h3>' + data.notes + '</h3>'); }
}
});
$('#backButton').click(function(){
// hide current display and header
$('#dvdDetailsDisplay, #dvdTitleHeader').hide();
// load main view again
loadDvdCollectionView();
});
}

The problem is that, this piece of code:
$('#backButton').click(function(){
// hide current display and header
$('#dvdDetailsDisplay, #dvdTitleHeader').hide();
// load main view again
loadDvdCollectionView();
});
is placed inside your displayDvd() function.
So when the first time your <td> is clicked, the displayDvd() is called and your #backButton callback is added.
Then you hit the #backButton, the callback function is called, everything should work fine here.
However, when you hit the <td> 2nd time, displayDvd() is called again and another click callback is added to #backButton again, also.
This is where the bug occurred. Now your #backButton have 2 same click callback functions attached. So when you click on it, 2 loadDvdCollectionView() are called simultaneously.
Simply move the piece of code into $(document).ready() callback should fix the problem.

You're hiding the DOM elements, but you're not removing them from the DOM. Try the following to remove the content from dvdDetailsDisplay and dvdTitleHeader:
$('#backButton').click(function(){
// hide current display and header
$('#dvdDetailsDisplay, #dvdTitleHeader').empty();
// load main view again
loadDvdCollectionView();
});

How do I use session variables with jQuery?

I have a button on one page another button on a different page. This second button has the text in it "0 items selected". When the first button is clicked I want to increase the number in the second button by one.
Seeing it is transferring data over different pages I didn't manage to do it the standard way.
Please do not suggest PHP, I am unable to use it.
var yetVisited = localStorage[0];
if ($('.#CallToActionCustomise').click()){
localStorage++;
}
$('.#CallToActionCustomise').click(function(){
$(".Main_MenuButtonReview").append(localStorage);
});
<button class="Main_MenuButtonReview">0 items selected <i class="fa fa-caret-down"></i></button>

You need to access localStorage as if it were an Object, not an array.
Also, you can only store String values, so to get a number to perform math on, you will need to use parseInt.
localStorage.setItem('yetVisited', 0);
$(".Main_MenuButtonReview").text(localStorage.yetVisited + ' items selected');
$('.CallToActionCustomise').click(function()){
localStorage.yetVisited = parseInt(localStorage.yetVisited) + 1;
$(".Main_MenuButtonReview").text(localStorage.yetVisited + ' items selected');
}
Here's an example.

In addition to the above answer, I think you need to init some tag when it loaded.
Put this code on another page.
$(document).ready(function() {
if (typeof localStorage.yetVisited === 'undefined') {
localStorage.setItem('yetVisited', 0);
}
yetVisited = localStorage.yetVisited;
$('.Main_MenuButtonReview').text(yetVisited + ' items selected');
});
$(document).ready(function() {
// this area means after your page(document) ready completely.
});

Transfer data from one page to another jQuery Mobile

I using PhoneGap to create a Geolocation App following this excellent tutorial (link). Unfortunatelly, I'm having an issue that I can't figure out. The relevant parts that are giving me a headache are these:
//Section 1
$('#history').on('pageshow', function () {
tracks_recorded = window.localStorage.length;
$("#tracks_recorded").html("<strong>" + tracks_recorded + "</strong> workout(s) recorded");
$("#history_tracklist").empty();
for (i = 0; i < tracks_recorded; i++) {
$("#history_tracklist").append("<li><a href='#track_info' data-ajax='false'>" + window.localStorage.key(i) + "</a></li>");
}
$("#history_tracklist").listview('refresh');
});
//Section 2
$("#history_tracklist li a").on('click', function () {
$("#track_info").attr("track_id", $(this).text());
});
//Section 3
$('#track_info').on('pageshow', function () {
var key = $(this).attr("track_id");
$("#track_info div[data-role=header] h1").text(key);
var data = window.localStorage.getItem(key);
data = JSON.parse(data);
});
Section 1 works just fine, the data is stored, and the list is created without any issues. But then in Section 2 is when everything goes to hell. By clicking on the element, a new attribute (track_id) is supposed to be created, but it doesn't. Therefore, in Section 3, the "var key" won't get a value, and as a consequence, "var data" will be null also. As you can imagine, nothing works from there. What am I doing wrong here? I only included what I considered the relevant code, but if more is needed I'll do so. Thansk!

In section 2, I think you just need to delegate click handling to the "#history_tracklist" container, as follows :
$("#history_tracklist").on('click', "li a", function () {
$("#track_info").attr("track_id", $(this).text());
});
Without delegation you have a rule saying :
when any existing li a element within #history_tracklist is clicked execute my function
With delegation, you have a rule saying :
when any existing or future li a element within #history_tracklist is clicked execute my function

jQuery - remove li from array with delete image

I'm attempting to make a menu bar that can have <li> elements added and removed. So far so good, but when I try and remove them I'm running into issues. I've toyed with this for a couple hours and now I'm wondering if this whole process could just be made easier (maybe an object?).
Anyways, here's the full code (80 lines), with comments to follow along.
var tabs = $('.accountSelectNav');
var titles = [];
var listItems = [];
// when the page loads check if tabs need to be added to the ul (menu bar)
$(document).ready(function(e) {
if ($.cookie('listItems') != null) {
console.log('not null');
//return "listItems" to it's array form.
listItems = JSON.parse($.cookie('listItems'));
$('.accountSelectNav').append(listItems);
}
});
$('.selectTable td:first-child').on('click', function(e) {
$('#home_select').removeClass('navHighlight');
//grab the text value of this cell
title = $(this).text();
$.ajax({
url:'core/functions/getAccountId.php',
type: 'post',
data: {'title' : title}
}).fail (function() {
alert('error');
}).done(function(data) {
accountId = $.trim(data);
// store values in the cookie
$.cookie('account_id', accountId, {expires : 7});
$.cookie('title', title, {expires : 7});
window.location = ('home_table.php');
});
// make sure the value is NOT currently in the array. Then add it
var found = jQuery.inArray(title, titles);
if (found == -1) {
titles.push(title);
addTab();
}
// make sure the value is NOT currently in the array. Then add it
found = jQuery.inArray(title, listItems);
if (found == -1) {
addListItem();
//place <li>'s in cookie so they may be used on multiple pages
$.cookie('listItems', JSON.stringify(listItems));
};
});
$("body").on("click", ".deleteImage", function (e) {
var removeTitle = $(this).closest('li').find('a').text();
var removeItem = $(this).closest('li')[0].outerHTML;
//remove title from "titles" array
titles = jQuery.grep(titles, function (value) {
return value != removeTitle;
});
//remove <li> from "listItems" array
listItems = jQuery.grep(listItems, function (value) {
return value != removeItem;
});
// this shows the <li> is still in the listItemsarray
console.log(listItems);
// put the array back in the cookie
$.cookie('listItems', JSON.stringify(listItems));
removeTab(this);
});
$("body").on("mouseover", ".accountSelectNav li", function(e) {
$(this).find('.deleteImage').show();
});
$("body").on("mouseleave", ".accountSelectNav li", function(e) {
$(this).find('.deleteImage').hide();
});
function addTab() {
tabs.append('<li class="navHighlight">' + '' + title + '' + '' + '<img src="images/delete.png" class="deleteImage"/>' + '' + '</li>');
};
function removeTab(del) {
$(del).closest('li').remove();
}
function addListItem() {
var s = ('<li class="navHighlight">' + '' + title + '' + '' + '<img src="images/delete.png" class="deleteImage"/>' + '' + '</li>');
listItems.push(s);
}
So you see I have two arrays of equal length that should always be the same length. One stores the title to be displayed in the tab, the other holds the html for the <li> which will be appended to the <ul>. I have no problem removing the title from its array. However removing the <li> from it's array is becoming a rather big hassle. You see when I get the <li> element after its been inflated the html inside does not exactly match what was put in, the browser adds style elements.
Example, the variable "removeItem" represents the html value of the selected <li> I wish to remove. It looks like this:
<li class="navHighlight">Test1<img src="images/delete.png" class="deleteImage" style="display: inline;"></li>
yet the value in my array "listItems" looks like this:
<li class="navHighlight">Test1<img src="images/delete.png" class="deleteImage"/></li>
So my attempt at removing it from my array always fails because they aren't a perfect match.
Now my question is how do I remove this <li> item? Also is there an easier way to do this whole process and I'm just not seeing it?
Thanks for your time.
EDIT
Fiddle by request here
Easiest way I can explain it.
Click the link to the fiddle.
Click any cell in the "App Name" column
This will add a <li> to the <ul> (menu) above of the table
When you hover over the <li> a picture appears
Click the picture
This should remove the <li>, both from the <ul> and from the array listItems
right now it does not

In the process of making this easier to check, I've taken your JSFiddle and did the following:
removed extra console.log and comments
removed interaction with cookies (since I did not have them in the first place, I figured they wouldn't just the first scenario)
After doing so I reached a point (you can see it here) where the desired functionality just works.
I even went ahead and removed the ajax stuff because that alert was driving me crazy. (here)
Since this works fine, my guess is that your issue lies between the lines that I removed.
Your usage of cookies is as follows:
To load existing tabs and add them back again
To save account_id and title, which is not used back again
To persist the listItems after a new item has been added
I then opened up the console with your version of the fiddle and the execution of javascript stops at $.cookie() with the error undefined is not a function.
This clearly indicates that the issue present in the Fiddle is that jQuery.cookie is not present and so those calls are halting the execution of the rest of your script. This also explains why it just started working when I took them out.
I posted the whole process of how I got there to indicate how I trimmed down the problem to specific parts, which is useful to reduce the problem space. When you're out of options and reach a place when you're lost, it's easier to post a question with less code and the specific part of the problem that you've identified. This will help you in finding the issues that you're facing and StackOverflow to provide proper answers to your questions.
Hope it helps!

Here is the solution I came up with. It should be much easier for people to understand than my original post. Although it's a long read it may be worth it, especially for new developers.
The point of this code is to make a menu bar out of an un-ordered list or <ul>. The menu bar needs to be used on multiple pages. So I'll be using cookies.
I start with this code to get a text value from my table.:
$('.selectTable td:first-child').on('click', function(e) {
// This value will be used later for the name of the tab or `<li>` inside our menu bar or `<ul>`
title = $(this).text();
});
Then I place the value in an array. I do this only if the array does not already have this string inside it. I do not want duplicates:
var found = jQuery.inArray(title, titles);
var titles = [];
if (found == -1) {
titles.push(title);
}
Then I store the array into a cookie, using a library like this:
$.cookie('titles', JSON.stringify(titles));
Now when any page loads that needs this menu bar I run this code to check if there are any values:
$(document).ready(function() {
if ($.cookie('titles') != null) {
titles = JSON.parse($.cookie('titles'));
}
});
Now I need to loop through the array. When I loop through the array I have to do 3 things:
1) Grab the string value.
2) Add the html to my new string so it becomes a list item or <li>.
3) Append the newly created <li> to our <ul>.
Like so:
for(var i = 0; i < titles.length; i++) {
var str = titles[i];
var listItem = '<li class="navHighlight">'
+ '<a href="#">'
+ str
+ '</a>'
+ '<a href="#">'
+ '<img src="images/delete.png" class="deleteImage"/>'
+ '</a>'
+ '</li>';
$('.accountSelectNav').append(listItem);
}
Now, if I want to remove this <li> I click the delete image found inside our <li>. What delete image you say? Look at the html I added again. You will see I add an <img> tag in there.
Now delete like so:
$("body").on("click", ".deleteImage", function (e) {
// grabs the text value of my li, which I want to remove
var removeTitle = $(this).closest('li').find('a').text();
// runs through my titles array and returns an array without the value above
titles = jQuery.grep(titles, function (value) {
return value != removeTitle;
});
});
Then I simply place the new array inside my cookie once again. Like this:
$.cookie('titles', JSON.stringify(titles));
And finally I remove the tab like this:
removeTab(this);
function removeTab(del) {
$(del).closest('li').remove();
}
Yay, I'm done. So now, if anyone has a more elegant way of accomplishing this I'm listening. I have no doubt there's a better way, javascript/jQuery isn't even close to my strong point.
The full code can be found here.

Make a javascript function instead variables

Here I have a code that create a sidebar:
var side_bar_html = "<a href='javascript:google.maps.event.trigger(gmarkers[" + parseInt(gmarkers.length - 1) + "],\"click\");'>" + place.name + "</a><br>" + '<div class="raty" />' + "</br>";
$(side_bar_html).appendTo('#side_bar').filter('.raty').raty({
score : place.rating,
path : 'http://wbotelhos.com/raty/lib/img'
})
How I can create a function from this code to create a sidebar with function ...
So something like that:
function Create_a_sidebar_and_put_it_into_ID#sidebar () {
//for every marker to return html string
return "<div class='element'>"+place.name+"</br>"+place.rating+"</div>" + etc...
Becouse I have a problem with creating html, I dont know what to append where and I dont have contol over that
Is it possible?

If I'm understanding your question correctly, you're asking how you can take your first code block that creates a rating for a certain place, and refactor it so that you can arbitrarily create sidebars for places at will. So that's how I'll approach this answer.
As #Sime Vidas mentioned, you can start by taking the code that creates the sidebar itself and making that a function such as that below. I've modified the function a bit to take the javascript out of the href attribute (which is generally considered a bad practice) and replaced passing an html string into $.fn.init (which I've found steeply degrades performance) with using DOM methods to create elements. You also don't need the <br /> after your a element because divs by default are block elements.
function createSidebar(place) {
var $sidebarLink = $(document.createElement('a'));
var $raty = $(document.createElement('div'));
$sidebarLink.attr('href', '#').text(place.name).click(function(evt) {
evt.stopPropagation();
google.maps.events.trigger(gmarkers[parseInt(gmarkers.length - 1, 10)], 'click');
});
$raty.addClass('raty').raty({
score: place.rating,
path: 'http://wbotelhos.com/raty/lib/img'
});
return $([$sidebarLink, $raty]);
}
Now you can do things like
var $sidebar = $('#side_bar');
places.map(createSidebar).forEach(function($sidebarPart) {
$sidebar.append($sidebarPart);
});
Sorry if I'm off track with answering your question, but I think this is what you were asking. If not feel free to leave a comment and we can talk about it more!