How to delegate focus event? [duplicate]

Answer 1

Under .on() jquery document, there is a description:

The focus and blur events are specified by the W3C to not bubble, but jQuery defines cross-browser focusin and focusout events that do bubble. When focus and blur are used to attach delegated event handlers, jQuery maps the names and delivers them as focusin and focusout respectively. For consistency and clarity, use the bubbling event type names.

Hope this would be useful.

And you can try this code:

var default_input_value = null;
jQuery('body').on('focusin focusout', 'input[type="text"]', function(event){
    if(event.type === 'focusin'){
        default_input_value = jQuery(this).val();
        jQuery(this).val('');
    }else if(event.type === 'focusout'){
        if(jQuery(this).val().length === 0)
        jQuery(this).val(default_input_value);
    }
});