I want to prevent default behavior of a link (a) then do the default behavior, let's say open open a link in a new window.
Here is some HTML code:
<a href="somewhere" target="_blank" id="mylink">
And the JS code:
document.getElementById('mylink').addEventListener('click', function (e) {
e.preventDefault();
axios.post('options', new FormData(document.querySelector('#myform')))
.then(function(){
// Here I want to do what the link should have done!
});
});
I know I can do something like this:
window.open(e.target.href);
But it's not an option because the browser consider this as a popup. And I don't want to rewrite something in JS, just consider the link as usual: this link has to do its default behavior (which was prevented).
Is there a way to do this?
Here is some idea:
var openingPopup = false;
document.getElementById('mylink').addEventListener('click', function (e) {
if(!openingPopup){
e.preventDefault();
axios.post('options', new FormData(document.querySelector('#myform')))
.then(function(){
// make sure this would not run twice
openingPopup = true;
document.getElementById('mylink').click();
});
}else{
// skipping this only for one time
openingPopup = false;
}
});
This way,
you run the popup opener click handler once,
then prevent the others,
trigger the click event again manually,
this time do nothing, but allow others to run.
As per #Electrox-Qui-Mortem 's suggested link, after you complete your pre-process(es), you can remove the event listener and call the click again.
(relevant MDN link: https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/removeEventListener )
const anchor = document.getElementById('anchor');
anchor.addEventListener('click', test);
function test(e){
e.preventDefault();
alert('test');
if( true ){
console.log( this );
this.removeEventListener('click', test);
this.click();
}
}
<a id="anchor" href="https://www.google.com">Test</a>
It's got wonky performance inside code testing tools (like JSfiddle and CodePen) -- you would have to test it in your actual application to make sure if it works appropriately for your use case.
I've only had good results with removeEventListener when referencing an outside function as the "listener" func. In this case test()
In a more "native" way you could create a new "click" event which is not cancelable and trigger it against the same element.
var anchor = document.querySelector('#target');
function triggerClick(target) {
var newClick = new MouseEvent('click', {
view: window,
bubbles: true,
cancelable: false
});
target.dispatchEvent(newClick);
}
anchor.addEventListener('click', function(e) {
e.preventDefault();
if(e.defaultPrevented) {
alert('Prevented!');
triggerClick(anchor);
}
else {
alert('Not prevented');
}
});
Click me!
Here the key is the cancelable: false in the new event created in the function triggerClick(target), which bypass the e.preventDefault().
In the embedded example on StackOverflow it doesn't work, but here's a JSFiddle!
Related
I am trying to develop some code to allow the user show/hide a block level element by clicking a button.
The HTML structure is like below
<div class="chat_container"><a class="crm" href="https://google.com" target="_blank">Chat?</a><button id="close_chat"><</button></div>
I have written a click() function for #close_chat which amongst other things changes the ID of the button to #open_chat. I then use the on() method on #open_chat to modify some classes and ids on various elements. In isolation both these methods work, however when combined they don't work. I have noticed that when I click #close_chat even though the ID changes to #open_chat the original event is still attached to the button. After doing some search I suspected the issue might have been related to events bubbling up, but now I am not so sure, still I added event.stopPopagation() to my click function and I can see it appears to be called correctly. I have also tried using the one() method, this appeared to get closer to the behavior I was expecting at the DOM level but still didn't working
My expected behavior is the click() function is called when the user clicks #close_chat, the event is then unbound allowing the .on() event to be called on #open_chat. Id than of course have to reset the original functionality. My code looks like this
$(document).ready(function () {
var close = "<button id='close_chat'><</div>";
var container = $("<div />");
container.addClass("chat_container");
var crmChat = $("<a />");
crmChat.addClass("crm");
crmChat.attr("href", "https://google.com");
crmChat.attr("target", "_blank");
crmChat.text("Chat?");
console.log(crmChat);
console.log(container);
$(container).insertAfter("#heading");
$(container).prepend(crmChat);
$(close).insertAfter(crmChat);
$("#close_chat").click(function (event) {
$("#close_chat").removeAttr("id").attr("id", "open_chat");
event.stopPropagation();
alert(event.isPropagationStopped());
//return false;
});
$(".chat_container").on("#open_chat", "button", function () {
//$(".crm_chat_container").addClass("animate-open").removeClass("animate-close");
$("#open_chat").html(">").removeAttr("id").attr("id", "reopen");
//event.stopPropagation();
});
});
any help is greatly appreciated
Sam
edit, I have now updated my code to look like so
//onclick function for our close button
$("#close_chat").click(function (event) {
attachClosedChatListner();
});
function attachOpendChatListener() {
$(".chat_container").on("click","#open_chat", function () {
$("#open_chat").removeAttr("id").attr("id", "close_chat");
$("#close_chat").html("<")
$(".crm_chat_container").removeClass("animate-close").addClass("animate-open");
});
//attachClosedChatListner();
}
function attachClosedChatListner() {
$("#close_chat").off('click');
$("#close_chat").removeAttr("id").attr("id", "open_chat");
$("#open_chat").html(">")
$(".chat_container").removeClass("animate-open").addClass("animate-close");
//attachOpendChatListener();
}
What about re-attaching the event?
$("#close_chat").click(function (event) {
$("#close_chat").removeAttr("id").attr("id", "open_chat");
attachOpenChatListener();
event.stopPropagation();
alert(event.isPropagationStopped());
//return false;
});
function attachOpenChatListener() {
$("#close_chat").off('click');
$(".chat_container").on("#open_chat", "button", function () {
//$(".crm_chat_container").addClass("animate-open").removeClass("animate-close");
$("#open_chat").html(">").removeAttr("id").attr("id", "reopen");
//event.stopPropagation();
});
}
I managed to work this out, the click function was causing the problem
//onclick function for our close button
$("#close_chat").click(function (event) {
attachClosedChatListner();
});
I've replaced it with .on and it works now
$(".crm_chat_container").on("click", "#close_chat", function (event) {
$("#close_chat").off('click');
$("#close_chat").removeAttr("id").attr("id", "open_chat");
$("#open_chat").html(">");
$(".crm_chat_container").removeClass("primo-animate-open").addClass("animate- close");
attachCloseChatListener();
event.stopImmediatePropagation();
});
function attachCloseChatListener() {
$(".crm_chat_container").on("click", "#open_chat", function (event) {
$("#open_chat").off('click');
$(".crm_chat_container").removeClass("primo-animate-close").addClass("primo-animate-open");
$("#open_chat").removeAttr("id").attr("id", "close_chat");
$("#close_chat").html("<");
event.stopImmediatePropagation();
});
}
on thing is my click events appears to be firing multiple times, that is after clicking my buttons a few times I see several click events in dev tools.
Anyway, thanks for putting me on the right path
I've noticed while working for someone on a script that this special button ( the login one ): https://www.easports.com/fifa/ultimate-team/web-app/ does not allow to simulate a click on it in any possible way.
I'm extremely curious to know how they do it.
I've tried
var btn=$('#Login > div > div > button.btn-standard.call-to-action');
btn.click(); // or trigger('click');
// or
click = new Event(click);
btn.dispatchEvent(click);
// or
btn.trigger('mousedown');
// oh and also:
function click(x, y)
{
var ev = new MouseEvent('click', {
'view': window,
'bubbles': true,
'cancelable': true,
'screenX': x,
'screenY': y
});
var el = document.elementFromPoint(x, y);
el.dispatchEvent(ev);
}
I've even tried mouseenter, followed by mousedown and mouseup;
How can one achieve this sort of feature?
Here's an example of what they might be doing. Event.isTrusted gives you information on if it was a user action or a created event. They probably have some logic around this:
From the docs:
The isTrusted read-only property of the Event interface is a Boolean
that is true when the event was generated by a user action, and false
when the event was created or modified by a script or dispatched via
EventTarget.dispatchEvent().
document.getElementById('btn').addEventListener('click', (e) => console.log(e.isTrusted));
// Simulate a click onload (should print false to the console)
document.getElementById('btn').click(); // false
// TODO: Click the Button manually, you should see 'true' being printed
<button id="btn">Button</button>
My guess is that if you look into their source code, you'd see something similar where they are just doing an .stopPropogation or .preventDefault if isTrusted is false.
So they are probably doing this:
document.getElementById('btn1').addEventListener('click', (e) => {
if (!e.isTrusted) { e.preventDefault(); return;}
console.log('Button clicked!');
});
document.getElementById('btn1').click(); // nothing printed to console.
<button id="btn1">Button</button>
I have a bit of a head scratcher when it comes to using stopPropagation in javascript. According to many different sources stopPropagation should stop bubbling of the event to parent elements, however, when I use it it seems to stop the event from being called after the first click. I have worked up a very simple bit of code to reproduce the behaviour below:
HTML:
<div id="root">
<div id="top">
<h1>Click Me!</h1>
</div>
</div>
js/jQuery:
var myEvent = document.createEvent("Event");
myEvent.initEvent("boop", true, true);
$("#root").on('boop', function (e) {
alert("root boop!");
});
$("#top").on('boop', function (e) {
// After this is called, this event handler will never fire again.
e.stopPropagation();
alert("top boop!");
});
$("h1").click(function (e) {
$("#top").get(0).dispatchEvent(myEvent);
// I know that $("#top").trigger will prevent the problem, what is wrong with the form above?
});
There is a Fiddle as well.
You dispatch myEvent on which you eventually call .stopPropagation(). Every click thereafter use the same instance of myEvent on which the propagation has been stopped.
You'll need to make a copy of the event before dispatching it if you want to be able to click multiple times.
...or you could rewrite your JavaScript like this:
$("#root").on('boop', function (e) {
alert("root boop!");
});
$("#top").on('boop', function (e) {
e.stopPropagation();
alert("top boop!");
});
$("h1").click(function (e) {
var myEvent = document.createEvent("Event");
myEvent.initEvent("boop", true, true);
$("#top").get(0).dispatchEvent(myEvent);
});
Working JS Fiddle
So I have a regular onclick event attached to a few buttons, each function that handles the onclick event does something different (so I can't reuse the same function for both events).
element1.onclick = function() {
if(this.classList.contains('disabled') {
return false;
}
// For example make an AJAX call
};
element2.onclick = function() {
if(this.classList.contains('disabled') {
return false;
}
// For example hide a div
};
I'm writing duplicate code for this 'disabled' class check, I want to eliminate this by hooking in some common onclick check then fire the regular onclick event if that check passes.
I know the below won't work but I think it will illustrate what I'm trying to do:
document.addEventListener('click', function() {
// 1. Do the disabled check here
// 2. If the check passes delegate the event to the proper element it was invoked on
// 3. Otherwise kill the event here
});
I'm not using any JavaScript library and I don't plan to, in case someone comes up with 'Just use jQuery' type answers.
EDIT: Had to pass boolean third argument to addEventListener as true and everything is fine.
Use event capturing, like so:
document.addEventListener('click', function(event) {
if (/* your disabled check here */) {
// Kill the event
event.preventDefault();
event.stopPropagation();
}
// Doing nothing in this method lets the event proceed as normal
},
true // Enable event capturing!
);
Sounds like you need to set the capture flag to true and then use .stopPropagation() on the event if a certain condition is met at the target, f.ex:
document.addEventListener('click', function(e) {
if ( condition ) {
e.stopPropagation();
// do soemthing else, the default onclick will never happen
}
}, true);
Here is a demo: http://jsfiddle.net/v9TEj/
You can create a generic function that receives a callback:
//check everything here
function handleOnclick(callback) {
if(this.classList.contains("disabled")) {
return false;
} else {
callback(); //callback here
}
}
//and now on every onclick, just pass the custom behavior
element1.onclick = function() {
handleOnClick(function() {
console.log('element1 onclick fire'); // For example hide a div
});
};
element2.onclick = function() {
handleOnClick(function() {
console.log('element2 onclick fire'); // For example ajax request
});
};
Edit
Based on your latest comment, let me know if this rewrite works for you... only one biding this time.
element1.customFunction = function() {
handleOnClick(function() {
console.log('element1 onclick fire'); // For example hide a div
});
};
element2.customFunction = function() {
handleOnClick(function() {
console.log('element2 onclick fire'); // For example ajax request
});
};
document.addEventListener('click', function() {
//1. grab the element
//2. check if it has the customFunction defined
//3. if it does, call it, the check will be done inside
};
I'm curious whats the best way to call a JS function with a href link in HTML. I don't use a library and i see alot of mention about jquery using event handlers ...
But if im not using a library can it still be done or will i have to use an on click type call ?
You can use event handlers with plain javascript. No framework is required. Here's a cross browser function I use:
// add event cross browser
function addEvent(elem, event, fn) {
if (elem.addEventListener) {
elem.addEventListener(event, fn, false);
} else {
elem.attachEvent("on" + event, function() {
// set the this pointer same as addEventListener when fn is called
return(fn.call(elem, window.event));
});
}
}
And, an example of using it would be like this:
HTML:
<a id="myLink" href="#">Click ME</a>
Javascript:
var link = document.getElementById("myLink").
addEvent(link, "click", function(e) {
// process the click on the link here
});
If you don't want the default click of a link to happen, then you need to prevent the default behavior from the event handler like this:
var link = document.getElementById("myLink").
addEvent(link, "click", function(e) {
// process the click on the link here
// prevent default action of the click
if (e.preventDefault) {
e.preventDefault(); // normal browsers
} else {
e.returnValue = false; // older versions of IE (yuck)
}
});
try this
function test() { alert (''); }
<a href="#" onclick="test();" />
Basically there are two ways:
...
and
...
(in this case someFunction must return false)
I prefer the latter.