简体   繁体   中英

Blur to trigger Change event

I have the following code:

$('.subtle-input').live('blur', function() {
    // this will fire all the time
});

$('.provider-rate-card input[type="text"]').live('change', function() {
    // this will fire some of the time, only when value is changed.
});

How do I make sure that the blur function happens before the change function, whenever the change function occurs?

Check out this jsfiddle :

<div class="provider-rate-card">
    <input class="subtle-input" type="text" />
</div>

$(function() {


    //This closure is simply here because you will be using a global variable
    //It helps prevent pollution of the global namespace, which is a good
    //practice in Javascript.
    (function() {
        //defines the flag
        var changed = false;

        $('.subtle-input').on('blur', function() {
            blurFunction(changeFunction);
        });

        $('.provider-rate-card input[type="text"]').on('change', function() {
            //sets the flag
            changed = true;
        });

        function blurFunction(func) {
            //do something every time it blurs
            console.log('blurred'); 

            //you will provide this callback as a parameter (see above)
            return func();
        }

        function changeFunction() {
            //checks the flag
            if(changed === true) {
                //do something whenever the value changes
                console.log('changed'); 

                //reset
                changed = false;
            }
        }
    })();

});

Could you just move the code into a function like so:

var doSomething = function() {
    // do something
};

$('.subtle-input').live('blur', function() {
    // this will fire all the time
    doSomething();
});

$('.provider-rate-card input[type="text"]').live('change', function() {
    // this will fire some of the time, only when value is changed.
    doSomething();
});

Or in your case would the two events fire in sequence such that you wouldn't want that function to execute twice? In that case, maybe you would like to use a flag like 'charlietfl' said in the comment. Eg:

var doneSomething = false;

var doSomething = function() {
    // do something
    doneSomething = true;
};

$('.subtle-input').blur(function() {
    // this will fire all the time
    doSomething();
});

$('.provider-rate-card input[type="text"]').change(function() {
    // this will fire some of the time, only when value is changed.
    if (doneSomething === false) {
        doSomething();
    }
    doneSomething = false;
});

From the comments, I did this all inside one function, manually checking the values:

$('.subtle-input').live('blur', function() {
    var existing_value = $(this).data('existing_value');
    var new_value = $(this).val();

    if (new_value != existing_value) {
        // do the change stuff
    }

});

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM