Simulate click in javascript [duplicate] - javascript

I want to simulate a click on any link on a page using JavaScript. If that link has some function binded to its 'onclick' event (by any other JS I don't have any control over), then that function must be called otherwise the link should behave in the normal manner and open a new page.
I am not sure that just checking the value of the 'onclick' handler would suffice. I want to build this so that it works on any link element.
I have no control over what function maybe binded to the onclick event of the link using whichever JS library (not necessarily jQuery) or by simply using JavaScript.
EDIT: With the help of the answers below, it looks like it is possible to check for event handlers attached using jQuery or using the onclick attribute. How do I check for event handlers attached using addEventListener / any other JS library so that it is foolproof?

You can use the the click function to trigger the click event on the selected element.
Example:
$( 'selector for your link' ).click ();
You can learn about various selectors in jQuery's documentation.
EDIT: like the commenters below have said; this only works on events attached with jQuery, inline or in the style of "element.onclick". It does not work with addEventListener, and it will not follow the link if no event handlers are defined.
You could solve this with something like this:
var linkEl = $( 'link selector' );
if ( linkEl.attr ( 'onclick' ) === undefined ) {
document.location = linkEl.attr ( 'href' );
} else {
linkEl.click ();
}
Don't know about addEventListener though.

Why not just the good ol' javascript?
$('#element')[0].click()

Just
$("#your_item").trigger("click");
using .trigger() you can simulate many type of events, just passing it as the parameter.

Easy! Just use jQuery's click function:
$("#theElement").click();

Try this
function submitRequest(buttonId) {
if (document.getElementById(buttonId) == null
|| document.getElementById(buttonId) == undefined) {
return;
}
if (document.getElementById(buttonId).dispatchEvent) {
var e = document.createEvent("MouseEvents");
e.initEvent("click", true, true);
document.getElementById(buttonId).dispatchEvent(e);
} else {
document.getElementById(buttonId).click();
}
}
and you can use it like
submitRequest("target-element-id");

At first see this question to see how you can find if a link has a jQuery handler assigned to it.
Next use:
$("a").attr("onclick")
to see if there is a javascript event assigned to it.
If any of the above is true, then call the click method. If not, get the link:
$("a").attr("href")
and follow it.
I am afraid I don't know what to do if addEventListener is used to add an event handler. If you are in charge of the full page source, use only jQuery event handlers.

All this might not help say when you use rails remote form button to simulate click to. I tried to port nice event simulation from prototype here: my snippets. Just did it and it works for me.

Related

Can we name an event handler in Javascript?

I was messing around with jQuery and event handlers, when I noticed this:
That uses jQuery, and without it:
How does the popup get a bar saying jQuery? Do browsers have integrated jQuery support to detect that? Or is there some way to name event handlers? I want to have my event display some other text, like how jQuery does.
NOTE: I don't want to use jQuery, as I want to know how jQuery does it.
I am not sure about what you are trying to do, but in Javascript you can always name functions
Example:
function myEventHandler(event) {
alert('event handler');
}
myEventHandler is the name of the function.
Hope this helps a little,
best,
Carsten
You can have custom names for your events if you want. We can use the trigger function for the same purpose.
Suppose you want to raise myEvent on <div id="my_div">.
We can simply
$("#my_div").trigger('myEvent');
and have a listener for the event:
$("#my_div").on('myEvent', function(event){
//Event handler
});
You can find some good documentation here -
https://learn.jquery.com/events/introduction-to-custom-events/
And this SO answer covers it thoroughly -
Custom events in jQuery?

two click handler on same element conflict

I have an element #div_1 which has inside the same document (not extern file) a plain JS function:
var trigger = false;
var div_1 = document.getElementById('div_1')
div_1.onclick = function() { trigger = true; };
and in an extern JS file I have a jQuery button click on the same element:
$(document).ready(function() {
$('#div_1').click(function() {
// some actions here
});
});
The problem is that it does ignore the jQuery clickhandler completely. Is there no way to have two seperate click handler which work both?
There must be something else going on in your code because you can certainly have multiple event handlers on an object.
You can only have one handler assigned via onclick, but that should, in no way, interfere with the jQuery event handler. Please show us a reproducible demo in a jsFiddle because there is likely some other problem with your code causing this.
FYI, I'd strong suggest you not use the onclick attribute for event handlers because there is danger of one event handler overwriting another, something that does not happen when using .addEventListener() or jQuery's .click(). But, neither .addEventListener() or jQuery's .click() will overwrite the onlick.
Here's a working demo that shows both event handlers working just fine: http://jsfiddle.net/jfriend00/4Ge52/

preventdefault not preventing when its inside button

I could not make preventdefault to prevent action. I apologize if the answer is too easy but I simply cant find the error. why is it not preventing from entering the link? jsfiddle given below.
http://jsfiddle.net/zwY5p/34/
$('#theForm').click(function(e) {
event.preventDefault();
alert('FORM!');
});
e != event
$('#theForm').click(function(event) {
event.preventDefault();
alert('FORM!');
});
The parameter passed to the handler function is what you need to execute preventDefault on. In your code, you are passing e but calling preventDefault on event.
preventDefault prevents the default browser action. It does not cancel the inline JavaScript, since that runs first. If you have to override that, just remove it (no event listener necessary):
$('#theForm').removeAttr('onclick').
your event parameter name e and the variable you are using event are different,
$('#theForm').click(function(event) {
event.preventDefault();
alert('FORM!');
});
Other than the errors pointed out on other answers there's another small issue, specifically in your markup declaration:
<!-- Use either the closing tag or the slash (/) in the opening tag -->
<button id="theForm" onclick="location.href='http://www.example.com'" />
go to google
</button>
On the topic, you have two different handlers attached to the button element, they are both handling the click event but they are still different and separate things. jQuery won't know about the handler defined in the markup:
var btn = document.getElementById('theForm');
jQuery._data( btn, "events" );
will return an array with a single element which is the handler added via jQuery.
Now you have to re-evaluate the need of two different handlers for the same element and event and apply conditions. Do you really need to do it this way?
You're using 2 'click' events.
You end up using preventDefault once, and it's used after the 1st click event has ran.
If you make your button an href, then your preventDefault will be working.
It will also make more sense, as the JS will be separated from the HTML markup.
Also, of course you must use the same parameter name. (function(event), with event.preventDefault for example).
If you are passing "e" as an event to the function then you should prevent the default action only for that "e" that you have passed and not for "event".
$('#theForm').click(function(e) {
e.preventDefault();
alert('FORM!');
});
jQuery preventDefault() method: http://api.jquery.com/event.preventDefault/

Is there any way to use javascript (jquery) to make an element behave **exactly** as if it was clicked (a unique situation)

I want to make 'select' element to behave as if it was clicked while i click on a completely different divider. Is it possible to make it act as if it was clicked on when its not??
here is my code
http://jsfiddle.net/fiddlerOnDaRoof/B4JUK/
$(document).ready(function () {
$("#arrow").click(function () {
$("#selectCar").click() // I also tried trigger("click");
});
});
So far it didnt work with either .click();
nor with the .trigger("click");
Update:
From what i currently understand the answer is no, you cannot. Although click duplicates the functionality it will not work for certain examples like this one. If anybody knows why this is please post the answer below and i will accept it as best answer. Preferably please include examples for which it will not work correctly.
You can use the trigger(event) function like ("selector").trigger("click")
You can call the click function without arguments, which triggers an artificial click. E.g.:
$("selector for the element").click();
That will fire jQuery handlers and (I believe) DOM0 handlers as well. I don't think it fires It doesn't fire handlers added via DOM2-style addEventListener/attachEvent calls, as you can see here: Live example | source
jQuery(function($) {
$("#target").click(function() {
display("<code>click</code> received by jQuery handler");
});
document.getElementById("target").onclick = function() {
display("<code>click</code> received by DOM0 handler");
};
document.getElementById("target").addEventListener(
'click',
function() {
display("<code>click</code> received by DOM2 handler");
},
false
);
display("Triggering click");
$("#target").click();
function display(msg) {
$("<p>").html(msg).appendTo(document.body);
}
});
And here's a version (source) using the onclick="..." attribute mechanism for the DOM0 handler; it gets triggered that way too.
Also note that it probably won't perform the default action; for instance this example (source) using a link, the link doesn't get followed.
If you're in control of the handlers attached to the element, this is usually not a great design choice; instead, you'd ideally make the action you want to take a function, and then call that function both when the element is clicked and at any other time you want to take that action. But if you're trying to trigger handlers attached by other code, you can try the simulated click.
Yes.
$('#yourElementID').click();
If you added the event listener with jquery you can use .trigger();
$('#my_element').trigger('click');
Sure, you can trigger a click on something using:
$('#elementID').trigger('click');
Have a look at the documentation here: http://api.jquery.com/trigger/
Seeing you jsfiddle, first learn to use this tool.
You selected MooTools and not jQuery. (updated here)
Now, triggering a "click" event on a select won't do much.
I guess you want the 2nd select to unroll at the same time as the 1st one.
As far as I know, it's not possible.
If not, try the "change" event on select.

jQuery - Add e.preventDefault() to all links click events?

I'm making a script in jQuery, and I have many click links click events. The thing is that I don't want the links I have click events for to do anything except the event, so I put an e.preventDefault(); at start of all my click events. But I have many click events, so is there a more simple way to just add the e.preventDefault(); to all the links click events? Remember I also have some links that I want to work as they should, so adding the e.preventDefault(); to all the links won't work, I only want to add it to links with click event.
you can use jquery namespaced events
http://docs.jquery.com/Namespaced_Events
HTH
you can do something like this for the links you want to add a click event but prevent the default behaviour
$('a.someClass').bind('click.dontClick',function(e){
e.preventDefault();
});
and for the links you want the normal click behaviour
$('a.clickClass').bind('click.doClick',function(e){
//your event handling code here
});
DEMO
You could try overriding the bind method, or the click method, before any of your binding code runs. Here I'm overriding the click method in a fairly hacky way. I would really recommend just calling preventDefault where you need it.
(function(){
var original = jQuery.fn.click;
jQuery.fn.click = function(){
// wrap your function in another function
var f = arguments[0];
arguments[0] = function(e) {
e.preventDefault();
f(e);
}
original.apply( this, arguments );
}
})();
Example in action: http://jsfiddle.net/k4jzb/
This SO answer details how to detect events on an element, but it looks like the asker took that answer and built a jQuery plugin for selecting elements based on their event listeners.
So you could use that plugin and then use some event delegation like so:
$(document).delegate('a:Event(click)', 'click', function (e) { e.preventDefault(); });
Warning: I've never used this plugin myself, and I'm not really familiar with custom jQuery CSS filters, so this might not actually work. At all.
I would take #3nigma's answer a little further. Usually the links you don't want to do default actions on are like <a href="#">
So filter out these links so the page doesn't jump when clicked. I use jQuerys filter() function. Not sure if that is the best. What do you think?
$('a').filter(function(i) {
return $(this).attr("href") === "#";
})
.bind('click.dontClick',function(e){
e.preventDefault();
})
Example here: Filter a tags containing #

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