Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
347 views
in Technique[技术] by (71.8m points)

javascript - How to reselect already selected option

The title seems confusing but what I want to do is...

I know how to handle only if the user select new option with this - $('select').change(function(){}).`

But not if the user wants to select the already selected option.

I've also tried with radio but same thing.

Okay for example I have a select with an option (red,blue,green).

<select>
    <option value="red">RED</option>
    <option value="blue">BLUE</option>
    <option value="green">GREEN</option>
</select>

and I have this script:

$('select').change(function(){
    var val = $(this).val();
    alert(val);
});

When I select option 'blue' it alerts a value 'blue', then I select 'green' it alerts 'green' as well. but when I select 'green' again nothing happens.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

This question comes to my attention as this is pretty basic stuff but no one actually dig into it further. OP has been using change(), but when you reselect the current selected option nothing is fired!

I tried click(), but it's firing before you can even choose an option.

With blur(), after you're done selecting nothing is fired because the the select element is still being focused, so you need to focus out like clicking outside for it to execute.

So I just suggested OP to switch to a radio type input then handle execution with click() event. That way you can still reselect already marked radio button.

But then I noticed that you just need to get the second click on <select> element because the first click opens the drop down list of options the second click returns the value of your selected option. So I came up with this:

$('select').click(function(){
    var $this = $(this);

    if ($this.hasClass('open')) {
        alert($this.val());
        $this.removeClass('open');
    }else {
        $this.addClass('open');
    }  
});

But now the problem is when you first click on <select> the drop down is being showned and we've also added the class 'open'. Then clicking elsewhere (without selecting an option) the drop down is hidden so when you click back on <select> the event is fired before you can even select an option.

So I added this code to fix that:

$(document).click(function(e){
   var $select = $('select');

    if (!$select.is(e.target)){
        $select.removeClass('open'); //reset the steps by removing open
    }
});

You can test it out in this jsfiddle. Cheers!


I think when <select> loses its focus is also a concern. So I added blur() event. See this update jsfiddle


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...