jQuery Simulate onClick - javascript

I am trying to simulate an onclick event on a drop down.
I have an IE object that is going to a page and I need to change a dropdown which has an onchange event:
$('select[name="blah"]').val(3).trigger('change');
$('select[name="blah"]').change(function(){
alert('changed');
});
When I try this, I would expect the alert to fire as it's technically an onchange.
http://jsfiddle.net/3y5hmyf0/
Is there a way to acomplish this?
More Details
My tool is controlling another IE page through an object. It navigates to the page and finds the select drop down on the page. From there, if you did it manually it has an onchange event when making a selection.
I am trying to get jQuery to simulate as if it was being clicked by a person to it triggers that on change event.
I have tried .trigger and .change and couldnt get either of them to work.

The only reason your code does not work is the order you are executing it. You need to connect the handler before triggering it:
JSFiddle: http://jsfiddle.net/3y5hmyf0/1/
// Wire up event handler
$('select[name="blah"]').change(function(){
alert('changed');
});
// Now generate the event
$('select[name="blah"]').val(3).trigger('change');
Note: Your manual change trigger is still required as a change event must normally be triggered by user interaction. Setting the value is not enough.

$('select[name="blah"]').change(function(){
NotifyChanged();
});
function NotifyChanged() {
alert('changed');
}
If you want to test the logic in the changed function, just call it.

Related

Triggering button click in jQuery not working

Using dot.js I'm adding a button to a specific web page that, when clicked, should add some text to a text field and then trigger another button to also be clicked. I simulate this by adding a click handler to my button which has this code:
var button = $('.some-class').find('button')[0];
console.log(button); // element I expect
button.click();
However, this doesn't work and I'm not sure why. If instead of .click() I perform .remove(), the button is removed from the page. If I use the console to execute the same code, the button does get clicked. This tells me I do have the right element, but there is something wrong with the click() event specifically.
Can someone explain why this isn't working in either Safari or Chrome? I've tried a lot of different things, but I'm new to jQuery so I'm probably missing some detail in how that works.
We went to the bottom of this in the chat. What probably caused the problem was another event-handler attached to (possibly) body, that undid the click.
So the solution was to stop the event from propagating:
event.stopPropagation();
While assigning the click event handler to the button you should use jquery on
This should ensure that whenever a new button with added with same selector (as in when event was assigned), event handled will be assigned to that button
Some examples here
The problem is the click() function is from jquery and you're attempting to fire the click function from the DOM object.
Try
$(button).click();
Here's a plunk.
http://plnkr.co/edit/2pcgVt
You can use the following statement.
var button = $('.some-class').find('button')[0].trigger('click');
try jquery's trigger() function:
$(button).trigger('click');
see jsfiddle: https://jsfiddle.net/665hjqwk/

What, if anything, is jQuery's change method doing here?

I'm familiar with attaching a handler to a checkbox's property change like this:
$(function(){
$("#chkbox").change(function(){
alert($(this).val())
});
});
However, doing this $("#chkbox").change(); will fire my alert, but the state of the checkbox won't actually change, which tells me that jQuery is just firing off handlers that it's already bound to an element. What is the use of calling it like [bourbon.io][1] does to close its modal?
$(".modal-fade-screen, .modal-close").on("click", function() {
$(".modal-state:checked").prop("checked", false).change();
});
If I omit the .change() at the end, the modal still closes and it seems everything works fine. What is the use of chaining change()? I ask, because I am trying to use Angular with this modal, and I need to invoke closing the checkbox's state so I can close the modal with some other buttons. angular.element(".modal-state:checked").prop("checked", false); seems to work fine, but since I'm not aware of anything like change in Angular
(it doesn't exist in jQlite), I want to be certain I'm not missing anything.
If you attach an change event listener to an element, every time a user triggers that event the event handler will fire. However, if you programmatically manipulate the element with change that would normally fire the event handler, the event handler would not fire. Therefore, you want trigger the change event manually once you made the change so that the event handler can be triggered.
$(".modal-state:checked").prop("checked", false).change();
//or $(".modal-state:checked").prop("checked", false).trigger('change');
What is the use of chaining change()? It all depends on what the change event handler does.

Click anchor, and be brought to linked page

I have a anchor on which I trigger a click with JavaScript. Please see this fiddle.
$(function() {
$('a').click();
});
For some reason, triggering the click does not bring me to the page specified by the href attribute of the anchor.
How can I have the click event also bring me to the page linked by the anchor?
It will not work like that, the call $('a').click(); is a short cut for $('a').trigger('click'); which tries to simulate a click action on the anchor element.
But the simulation is not absolute, though it will fire the registered event handler it will not completely simulate a use click trigger the default action.
As per the jquery doc for trigger
Description: Execute all handlers and behaviors attached to the
matched elements for the given event type.
and
Although .trigger() simulates an event activation, complete with a
synthesized event object, it does not perfectly replicate a
naturally-occurring event.
So I don't think it is possible to completely simulate a user action and trigger a redirection using this method
Seems to be something to do with jQuery and the trigger method, works fine when you change [object object] to [object]. Here is the fiddle. Enjoy!
$(function() {
$('a').get(0).click();
});

How to trigger change event for Chosen (jQuery)

Before I click reset button I choose "Company" in Chosen (dropdown list). The event occurs normally after I click reset. I choose "Company" again but event change in dropdownlist doesn't occur.
Could anyone tell me how to trigger the change event for dropdownlist after clicking reset button and then the same element?
The code I have so far:
$("#mainMenu").change(function(e){
e.preventDefault();
loadFirstManu(true);
});
Code for the reset button:
$("#btn_reset").click(function() {
CKEDITOR.instances.ckeditor.setData('');
$('.mchosen').each(function() {
$(this).val('').trigger('liszt:updated');
$('#submenu').attr('disabled', 'disabled').html('');
$('#secondsubmenu').attr('disabled', 'disabled').html('');
$('#s-menu').removeClass('required').html('');
$('#secondsubmenu').removeClass('validate[required]');
$('#tabmenu').attr('disabled', 'disabled').html('');
$('#tab').removeClass('required').html('');
});
});
This is what i figured out:
$('#my-select').val(5).trigger("liszt:updated")
liszt:updated is no longer working in new version of chosen instead use below as Alexandru Cojan's answer suggesting
trigger("chosen:updated");
for newer version of chosen the event is "chosen:updated"
$(selector).trigger("chosen:updated")
If i need just to refresh value in chosen select - .trigger('chosen:updated') is enough. But if I have change handler and want it to be called - i need to do .trigger('chosen:updated').change()
I don't know if this is your case or not, but your code above should work,
$("#mainMenu").change(function(e){
e.preventDefault();
loadFirstManu(true);
});
but please notice that "change" event occurs on most browsers when you unfocus the select input
So when you click reset, just before executing the reset action the onchange is triggered.
Now try clicking outside the select input after changing the selection and see if it still works or not
Maybe you should try using .on, as your $('#mainMenu') may have changed somewhere (Can't say without an example). Try doing this:
$("body").on('change','#mainMenu',function(){
...
});
or any parent selector instead of "heavy" body
If I am not wrong to understand you then you want to trigger the event change after click on the reset button.
you can do this by simply adding one line to your code
//code
$("#btn_reset").click(function(){
// your code here
$("#mainMenu").trigger('change');
//you can write this as per your requirements ie. at start or end.
});

jQuery / JavaScript Bubbling and stopPropagation doesn't work

I'm making an edit button which pops up a modal box with a form to edit it. jQuery then sends this form to my server and I get a JSON response back. However, due to my bubbling issue, if I click on, for example, all of the edit buttons and then click on the last one and change a field, it does it across all of them.
$('.edit').click(function(event){
//more code...
modal_submit(the_id);
event.stopPropagation();
});
and then the submit event:
function modal_submit(the_id){
$('#modal form').submit(function(){
//This will alert every time I have EVER clicked on an edit button
alert(the_id);
return false;
});
}
finally all of this is inside of a getScript:
$.getScript('js/edit.js',function(){
create_edit_btn();
});
I've only used this 1 other time, and it worked, but I also had to do this.event.stopPropagation, but if I do "this" now it says this.event is undefined, but like I said, this exact code worked before for another script I did.
Does anyone have any ideas? :\
EDIT:
the html is:
<li>
<input id="item1" type="checkbox" value="webhosting|15" title="Web Hosting">
<p>Hosting for your web site</p>
</li>
An event can have multiple event listeners. Each time you use $(element).submit(whateverFunction) you are adding another whateverFunction to the submit event. If you only want only the last listener to be the action that is taken upon envoking the event, try doing this:
function modal_submit(the_id){
$('#modal form').unbind(); // this will remove all other event listeners from this element
$('#modal form').submit(function(){
//This will alert every time I have EVER clicked on an edit button
alert(the_id);
return false;
});
I think you event.stoppropagation does its job already. It stopped all the bubbling on the click event of the button (ie, if you try checking the document body, it won't have mouse click event anymore). The reason why codes within submit of the form is still executed, is because this is called by the button's default action.
Together with event.stoppropagation(), I suggest you include this:
event.preventDefault();
So that the default action will not used and only the codes within your handler is executed.
Is this in the function that creates edit buttons?
$('.edit').click(function(event){
//more code...
modal_submit(the_id);
event.stopPropagation();
});
If it this, then it will add this handler multiple times to the same elements, causing a flurry of alerts. Use live, which will place the handler on every matched element, even if is is added later in execution.

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