I have the following function that I would like to work with a class "pause" instead of an id.
I did see a few topics about this however I didn't quite understand how would this work.
Thanks!!!
function onPlayerReady(event) {
document.getElementById('pause').onclick = function() {
youtubePlayer1.pauseVideo();
youtubePlayer2.pauseVideo();
youtubePlayer3.pauseVideo();
e.preventDefault();
};
};
Using jQuery you can attach a click handler to all elements that have the pause class.
$(".pause").on("click", function () {
youtubePlayer1.pauseVideo();
youtubePlayer2.pauseVideo();
youtubePlayer3.pauseVideo();
e.preventDefault();
});
As you can guess from the name, the getElementsByClassName() function can return multiple (or zero) results. This is because element ids must be unique, but many different elements can have the same class.
So all you need to do is iterate over the results and add the click handler as before:
function onPlayerReady(event) {
var elem = document.getElementById('pause')
for(var i in elem) {
elem[i].onclick = function() {
youtubePlayer1.pauseVideo();
youtubePlayer2.pauseVideo();
youtubePlayer3.pauseVideo();
e.preventDefault();
}
}
};
Even though you only expect a single result, this is how you should do it to prevent errors.
Related
function generalShowPopup(click_element, show_elements) {
click_element.on("click", function(event) {
show_elements.each(function() {
$(this).show();
});
event.preventDefault();
});
}
With the above function I intend to show an element when a certain link is clicked.
Calling the function like this (one second argument) works fine:
generalShowPopup($(".popup_link"), $(".popup") );
But how could I pass two elements to the second argument, i.e show two elements when a certain link is clicked?
Just use a comma, ,, inside the selector string, and there really is no reason to use .each():
generalShowPopup($(".popup_link"), $(".popup,.selecctor2, #selector3") );
No need to use each:
function generalShowPopup(click_element, show_elements) {
click_element.on("click", function(event) {
event.preventDefault();
show_elements.show();
});
}
A quicker way to write all this is:
$(function() {
$(".popup_link").on('click', function(event) {
event.preventDefault();
$(".popup,.selecctor2, #selector3").show();
});
});
$(".popup") is a jQuery Collection,
Just use .add() method:
generalShowPopup($(".popup_link"), $(".popup").add(".another") );
I'm trying to make a script that, when you click on an anchor, a $.get function will get the anchor's href and then the href will be removed, but I cannot edit anything about the anchor from inside de get element. Example:
// make anchor disappear for example (doesn't work)
$('.belovedanchor').click(function(e) {
$.get($(this).attr('href')).done(function() {
$(this).hide();
});
});
// make an anchor disappear using a function (doesn't work too)
$('.belovedanchor').click(function(e) {
function do() { $(this).hide(); };
$.get($(this).attr('href')).done(function() {
do();
});
});
I don't understand why $(this) change to work with the $.get function istead of the .click event.
How would you guys do it?
You have a couple problems. Edit: Only one problem -- I now see from your comment below that belovedanchor is not the actual selector in your code.
First, your jQuery selector for the click event handler is most likely incorrect. Change $('belovedanchor') to $('.belovedanchor') or $('#belovedanchor') depending if the anchor is identifiable by either class or element ID respectively.
Second, this in the do callback function does not refer to the anchor. In JavaScript, scope is set at the function level, so anytime you declare a new function, this will refer to that new scope.
Do this instead:
$('belovedanchor').click(function(e) {
var anchor = $(this);
function do() { anchor.hide(); };
$.get($(this).attr('href')).done(function() {
do();
});
});
Simplified:
$('belovedanchor').click(function(e) {
var anchor = $(this);
$.get(anchor.attr('href')).done(function() {
anchor.hide();
});
});
This may work properly
$('.belovedanchor').click(function() {
var selectedancor = $(this);
var myurl = $(this).attr('href');
$.get(myurl, function() {
selectedanchor.hide();
});
});
I have a list view for delete id. I'd like to add a listener to all elements with a particular class and do a confirm alert.
My problem is that this seems to only add the listener to the first element with the class it finds. I tried to use querySelectorAll but it didn't work.
var deleteLink = document.querySelector('.delete');
deleteLink.addEventListener('click', function(event) {
event.preventDefault();
var choice = confirm("sure u want to delete?");
if (choice) {
return true;
}
});
List:
<?php
while($obj=$result->fetch_object())
{
echo '<li><a class="delete" href="removeTruck.php?tid='.$obj->id.'">'.$obj->id.'</a>'
. '
</li>'."\n";
}
/* free result set */
$result->close();
$mysqli->close();
?>
You should use querySelectorAll. It returns NodeList, however querySelector returns only the first found element:
var deleteLink = document.querySelectorAll('.delete');
Then you would loop:
for (var i = 0; i < deleteLink.length; i++) {
deleteLink[i].addEventListener('click', function(event) {
if (!confirm("sure u want to delete " + this.title)) {
event.preventDefault();
}
});
}
Also you should preventDefault only if confirm === false.
It's also worth noting that return false/true is only useful for event handlers bound with onclick = function() {...}. For addEventListening you should use event.preventDefault().
Demo: http://jsfiddle.net/Rc7jL/3/
ES6 version
You can make it a little cleaner (and safer closure-in-loop wise) by using Array.prototype.forEach iteration instead of for-loop:
var deleteLinks = document.querySelectorAll('.delete');
Array.from(deleteLinks).forEach(link => {
link.addEventListener('click', function(event) {
if (!confirm(`sure u want to delete ${this.title}`)) {
event.preventDefault();
}
});
});
Example above uses Array.from and template strings from ES2015 standard.
The problem with using querySelectorAll and a for loop is that it creates a whole new event handler for each element in the array.
Sometimes that is exactly what you want. But if you have many elements, it may be more efficient to create a single event handler and attach it to a container element. You can then use event.target to refer to the specific element which triggered the event:
document.body.addEventListener("click", function (event) {
if (event.target.classList.contains("delete")) {
var title = event.target.getAttribute("title");
if (!confirm("sure u want to delete " + title)) {
event.preventDefault();
}
}
});
In this example we only create one event handler which is attached to the body element. Whenever an element inside the body is clicked, the click event bubbles up to our event handler.
A short and sweet solution, using ES6:
document.querySelectorAll('.input')
.forEach(input => input.addEventListener('focus', this.onInputFocus));
You have to use querySelectorAll as you need to select all elements with the said class, again since querySelectorAll is an array you need to iterate it and add the event handlers
var deleteLinks = document.querySelectorAll('.delete');
for (var i = 0; i < deleteLinks.length; i++) {
deleteLinks[i].addEventListener('click', function (event) {
event.preventDefault();
var choice = confirm("sure u want to delete?");
if (choice) {
return true;
}
});
}
(ES5) I use forEach to iterate on the collection returned by querySelectorAll and it works well :
document.querySelectorAll('your_selector').forEach(item => { /* do the job with item element */ });
I have several jQuery click functions- each is attached to a different DOM element, and does slightly different things...
One, for example, opens and closes a dictionary, and changes the text...
$(".dictionaryFlip").click(function(){
var link = $(this);
$(".dictionaryHolder").slideToggle('fast', function() {
if ($(this).is(":visible")) {
link.text("dictionary ON");
}
else {
link.text("dictionary OFF");
}
});
});
HTML
<div class="dictionaryHolder">
<div id="dictionaryHeading">
<span class="dictionaryTitle">中 文 词 典</span>
<span class="dictionaryHeadings">Dialog</span>
<span class="dictionaryHeadings">Word Bank</span>
</div>
</div>
<p class="dictionaryFlip">toggle dictionary: off</p>
I have a separate click function for each thing I'd like to do...
Is there a way to define one click function and assign it to different DOM elements? Then maybe use if else logic to change up what's done inside the function?
Thanks!
Clarification:
I have a click function to 1) Turn on and off the dictionary, 2) Turn on and off the menu, 3) Turn on and off the minimap... etc... Just wanted to cut down on code by combining all of these into a single click function
You can of course define a single function and use it on multiple HTML elements. It's a common pattern and should be utilized if at all possible!
var onclick = function(event) {
var $elem = $(this);
alert("Clicked!");
};
$("a").click(onclick);
$(".b").click(onclick);
$("#c").click(onclick);
// jQuery can select multiple elements in one selector
$("a, .b, #c").click(onclick);
You can also store contextual information on the element using the data- custom attribute. jQuery has a nice .data function (it's simply a prefixed proxy for .attr) that allows you to easily set and retrieve keys and values on an element. Say we have a list of people, for example:
<section>
<div class="user" data-id="124124">
<h1>John Smith</h1>
<h3>Cupertino, San Franciso</h3>
</div>
</section>
Now we register a click handler on the .user class and get the id on the user:
var onclick = function(event) {
var $this = $(this), //Always good to cache your jQuery elements (if you use them more than once)
id = $this.data("id");
alert("User ID: " + id);
};
$(".user").click(onclick);
Here's a simple pattern
function a(elem){
var link = $(elem);
$(".dictionaryHolder").slideToggle('fast', function() {
if (link.is(":visible")) {
link.text("dictionary ON");
}
else {
link.text("dictionary OFF");
}
});
}
$(".dictionaryFlip").click(function(){a(this);});
$(".anotherElement").click(function(){a(this);});
Well, you could do something like:
var f = function() {
var $this = $(this);
if($this.hasClass('A')) { /* do something */ }
if($this.hasClass('B')) { /* do something else */ }
}
$('.selector').click(f);
and so inside the f function you check what was class of clicked element
and depending on that do what u wish
For better performance, you can assign only one event listener to your page. Then, use event.target to know which part was clicked and what to do.
I would put each action in a separate function, to keep code readable.
I would also recommend using a unique Id per clickable item you need.
$("body").click(function(event) {
switch(event.target.id) {
// call suitable action according to the id of clicked element
case 'dictionaryFlip':
flipDictionnary()
break;
case 'menuToggle':
toggleMenu()
break;
// other actions go here
}
});
function flipDictionnary() {
// code here
}
function toggleMenu() {
// code here
}
cf. Event Delegation with jQuery http://www.sitepoint.com/event-delegation-with-jquery/
I have a bunch of elements that get three different classes: neutral, markedV and markedX. When a user clicks one of these elements, the classes toggle once: neutral -> markedV -> markedX -> neutral. Every click will switch the class and execute a function.
$(document).ready(function(){
$(".neutral").click(function markV(event) {
alert("Good!");
$(this).addClass("markedV").removeClass("neutral");
$(this).unbind("click");
$(this).click(markX(event));
});
$(".markedV").click(function markX(event) {
alert("Bad!");
$(this).addClass("markedX").removeClass("markedV");
$(this).unbind("click");
$(this).click(neutral(event));
});
$(".markedX").click(function neutral(event) {
alert("Ok!");
$(this).addClass("neutral").removeClass("markedX");
$(this).unbind("click");
$(this).click(markV(event));
});
});
But obviously this doesn't work. I think I have three obstacles:
How to properly bind the changing element to the already defined function, sometimes before it's actually defined?
How to make sure to pass the event to the newly bound function [I guess it's NOT accomplished by sending 'event' to the function like in markX(event)]
The whole thing looks repetitive, the only thing that's changing is the alert action (Though each function will act differently, not necessarily alert). Is there a more elegant solution to this?
There's no need to constantly bind and unbind the event handler.
You should have one handler for all these options:
$(document).ready(function() {
var classes = ['neutral', 'markedV', 'markedX'],
methods = {
neutral: function (e) { alert('Good!') },
markedV: function (e) { alert('Bad!') },
markedX: function (e) { alert('Ok!') },
};
$( '.' + classes.join(',.') ).click(function (e) {
var $this = $(this);
$.each(classes, function (i, v) {
if ( $this.hasClass(v) ) {
methods[v].call(this, e);
$this.removeClass(v).addClass( classes[i + 1] || classes[0] );
return false;
}
});
});
});
Here's the fiddle: http://jsfiddle.net/m3CyX/
For such cases you need to attach the event to a higher parent and Delegate the event .
Remember that events are attached to the Elements and not to the classes.
Try this approach
$(document).ready(function () {
$(document).on('click', function (e) {
var $target = e.target;
if ($target.hasClass('markedV')) {
alert("Good!");
$target.addClass("markedV").removeClass("neutral");
} else if ($target.hasClass('markedV')) {
alert("Bad!");
$target.addClass("markedX").removeClass("markedV");
} else if ($target.hasClass('markedX')) {
alert("Ok!");
$target.addClass("neutral").removeClass("markedX");
}
});
});
OR as #Bergi Suggested
$(document).ready(function () {
$(document).on('click', 'markedV',function (e) {
alert("Good!");
$(this).addClass("markedV").removeClass("neutral");
});
$(document).on('click', 'markedX',function (e) {
alert("Bad!");
$(this).addClass("markedX").removeClass("markedV");
});
$(document).on('click', 'neutral',function (e) {
alert("Ok!");
$(this).addClass("neutral").removeClass("markedX");
});
});
Here document can be replaced with any static parent container..
How to properly bind the changing element to the already defined function, sometimes before it's actually defined?
You don't bind elements to functions, you bind handler functions to events on elements. You can't use a function before it is defined (yet you might use a function above the location in the code where it was declared - called "hoisting").
How to make sure to pass the event to the newly bound function [I guess it's NOT accomplished by sending 'event' to the function like in markX(event)]
That is what happens implicitly when the handler is called. You only need to pass the function - do not call it! Yet your problem is that you cannot access the named function expressions from outside.
The whole thing looks repetitive, the only thing that's changing is the alert action (Though each function will act differently, not necessarily alert). Is there a more elegant solution to this?
Yes. Use only one handler, and decide dynamically what to do in the current state. Do not steadily bind and unbind handlers. Or use event delegation.