Develop Reference

How to select a option from list using Javascript, so that it also trigger an event

I am trying to automate something here. The website on which I run the Javascript,
When I click on an <option> element inside <select>. The website changes the content of another <select> below it. This only happens when I manually select an option.
But when I select an option using Javascript like this: No content gets changed:
document.getElementById("Category").selectedIndex = 8;

Try
let options= document.querySelectorAll('select option')
You can access the innerHTML property of first option using options[0].innerHTML
Add onChange event to you select element using
document.querySelector('select').addEventListener('change',()=>{
alert('Changed')
})
Hope it helps
Edit - You might also want to check the current selected option and want to make changes accordingly. You can check the current selected option by
document.querySelector('select').value //Returns the value of selected option

Disclaimer: There is no reproducible example, so this is my best guess.
The website you are talking about probably captures the click events and uses that to alter the selects. For example,
$("select > option").click(function(){
//do something
...
});
When you change the selectedIndex, yes, you are selecting a new option, but you are not sending the click event, so the above function is not called. You will need to inspect their source/provide more details for more clarity.

WooCommerce - Triggering variation select with custom select boxes

I'm trying to use FancySelect.js to style the select boxes used on WooCommerce and have managed a few but I'm struggling with the Variation form on product pages.
While FancySelect triggers a change event on the original select box, it appears to affect nothing. Looking at the javascript used in the variations form, it looks like they've unbinded the change event on the select box and are handling it some other way, by triggering events on the .variations_form instead. I can't seem to get it to work though.
My code is something along the lines of:
$('.summary select').fancySelect().on('change.fs', function() {
$(this).trigger('change.$');
$('.variations_form').trigger('woocommerce_variation_select_change');
});
I've tried triggering multiple events but none seem to have any affect.
Any ideas?
Thanks.

So it turns out that the original trigger didn't work, for reasons I can't quite work out. However, manually triggering a change event on the original select box worked to some degree, but it wouldn't update fancySelect's "Trigger" element. I think this was because the original select's options didn't get a :selected attribute (for whatever reason). I've had to add a custom event to fancySelect to manually trigger it's updateText() method.
Updated code:
$('.summary .options li').on('click', function(){
$('.summary select').trigger('change').trigger('select.fs');
});
And the additional event for fancySelect (which I'll try contribute to if I get chance):
sel.on('select.fs', function(){
updateTriggerText();
});
Cheers.

jQuery: generate Select element

I have a table with data, and when I click on a cell in a certain column, I want it to change into a select dropdown for the user to choose a category for that row (which will be written to the database by AJAX but that'll come later).
I've done something similar before with text boxes using this, which works great, but I'm not sure if I'm modifying it correctly.
I've created a JSFiddle which shows the problem I'm having. I click on the text and it turns into a select element as expected, but when I click on that to choose an option, the dropdown doesn't stay open and I can't select anything. Debugging has shown me that when I click the dropdown, it runs the $("td.ChooseType").click() routine again so I've tried to suppress that by removing the class then adding it back on on selection, but that hasn't solved it. On the rare occasion that the dropdown stays open, I am unable to select anything by either mouse or keyboard.
All of the users will be on IE8 unfortunately, so I need it to be compatible with that.
Thanks!

You need to use event delegation, as otherwise that click event is always bound to that td - regardless of whether its class changes.
Simply change:
$("td.ChooseType").click(function() {
To:
$("table").on('click', '.ChooseType', function () {
JSFiddle demo.

Purely as an alternative to the accepted answer, you can remove an attached handler with unbind. So instead of adding and removing the class, you could unbind and rebind your handler. Only requirement is that the function can't be in-line, but has to be declared separately.
example: http://jsbin.com/qiqunici/1/edit
var handler = function () {
$(this).unbind('click', handler); //unbind the clicked element only
//create and change the element
//inside the select-change event, instead of addClass, re-attach:
{
//$(this).parent().addClass("ChooseType").text(selected).find('select').remove();
$(this).parent().click(handler).text(selected).find('select').remove();
}
};
$("td.ChooseType").click(handler);

How can I choose a select option in jQuery as though it were clicked with the mouse?

I am building a search tool with various select drop downs that populate with options via AJAX. The possible options populated are based on the the option chosen in the preceding select drop down. For the purpose of this tool, I want to have the first select box hidden but still need to select an option in that box so that it triggers the AJAX call on the following box, something that is supposed to happen as the result of an "onchange" event.
I've tried all kinds of different code to simulate a mouse click selection of a particular option but, while I can get the option selected, it still isn't triggering the event properly to set off the AJAX call in the following select. This is as far as I've gotten:
jQuery('#form select').first().val('the-value').trigger('click').trigger('change');
From everything I've read, that should set the option value and trigger a change event much like clicking the option. Still, this isn't working. Thanks!

You only have to use val(), like any other field...
$("select").val("2").change();
http://jsfiddle.net/Loenix34/3LbjY/
We also use change() to call associated events.

Instead of setting the value of the select, set the selected property of the given option, and then trigger a change.
$("option[value='the-value']").prop('selected', true);
$("#form select:first").change();
Fiddle Demo

JQuery clean autocomplete combobox value

I used a jquery combobox for autocompletion and I needed to clean its value.
I got into a solution which is like this: http://jsfiddle.net/BbWza/30/
The problem is that the code below clears all textboxes of all combos in the screen. I'd like to clear only ONE combo (let's say the first one, for example).
$('.ui-autocomplete-input').focus().val('');
Although there is only one clear link button, it doesn't matter which combo will be cleared as long as only one is.
The solution should work for N combos in the screen. E.g. Each button should empty its corresponding combo.

You can add ids to the generated fields by adding this line as the last line of _create():
input.attr( 'id', $(select).attr( 'id' )+'-input' );
Now you can select individual fields with the ids:
$('#combobox-input').focus().val('');

To clear just only one combo you must select it with it's id:
$('#combobox').focus().val('');
$('#combobox').autocomplete('close');
with your code you are selecting all comboboxes because you are using a class selector.
EDIT if you want to make two buttons (one for each combobox) you could do:
$('.clicky').click(function() {
var combo= $(this).prevAll('input:first');
combo.focus().val('');
combo.autocomplete('close');
return false;
});
fiddle here: http://jsfiddle.net/BbWza/39/

Your jsfiddle is a little ambiguous as to which combo box should be cleared - there are two combo boxes but only one clear link, so it's not obvious if the link is supposed to clear just one or both combo boxes.
I suspect in the real world that each combo box would have it's own clear link. Selecting the right text box for your clear link all depends on your html. One simple case would be where the clear link is the next sibling to your <select> element:
<select class="combo">
...
</select>
Clear
Then you could create the combos in one call by using class. Then create the clear click handlers all at once. The handler would use .prevAll(".ui-autocomplete-input") to find its associated textbox.
$("select.combo").combobox();
$("a.clearCombo").click(function () {
$(this).prevAll('.ui-autocomplete-input').first()
.focus()
.val('')
.autocomplete('close');
return false;
});
Working demo at jsfiddle
If your link is not a sibling of your combo box, that's ok. Either find its parent that is a sibling and use the above approach. Or, if that won't work, find the common parent of both the combo and the link. This only works if the common parent contains only one combo and one link:
<span class="comboContainer">
<span>
<select class="combo">
...
</select>
</span>
Clear
</span>
You use .closest(".comboContainer") and .find(".ui-autocomplete-input"):
$("select.combo").combobox();
$("a.clearCombo").click(function () {
$(this).closest(".comboContainer").find('.ui-autocomplete-input')
.focus()
.val('')
.autocomplete('close');
return false;
});
Working demo at jsfiddle
The nice thing about these techniques is that the link doesn't need to know the id of its associated combobox. We can just infer it from the html. This makes it very easy to move combos around and add new ones.
Two suggestions:
Add a clear method to your plugin. Your widget users shouldn't have to know its internal workings. In your example, you have to know that widget uses .autocomplete(). This also prevents you from changing your implementation later. Adding a "clear" method would simplify your click handler to just $(this).prevAll("select.combo").combobox("clear").
Give your widget the option to create the clear button itself. Users can always disable it and add their own clear button if they want.

Well, in the example the following would only clear the last combobox:
$('.ui-autocomplete-input').last().focus().val('');
This would clear the first one:
$('.ui-autocomplete-input').first().focus().val('');

You can clear it in event "close" of the autocomplete
$("#your-input").autocomplete({
source: items,
close: function (event, ui) {
$(this).val("");
}
});

How to give clear button for autocombobox please tell me
You can add ids to the generated fields by adding this line as the last line of _create():
input.attr( 'id', $(select).attr( 'id' )+'-input' );
Now you can select individual fields with the ids:
$('#combobox-input').focus().val('');