Select2 validate and force user to select ast least X items

问题

I'm having some trouble trying to do some custom validation with a select2 jQuery plugin

I need to force user to select at least 2 items from the list. The select2 plugin has a property maximumSelectionSize that allows user to select up to X items from the list, but it does not have the "inverse" property. Also the required tag won't work because I need user to select more than one item.

As I'm working developing a custom validator with parsley validation plugin, I'd need to know how to get at any moment (commonly at form submit) the current quantity (number) of items chosen in a select2 field? Maybe with val() method?

Thanks

回答1:

Solved by:

1. Add data-parsley-cantmin="2" attribute to the select2 field

2. Initialize the ParsleyConfig object as following

   window.ParsleyConfig = {
       validators: {
           cantmin: {
               fn: function (value, requirement) {
                   //return value !== requirement;
                   if ($("#campoprofesionales").val())
                       if($("#campoprofesionales").val().length > 1) 
                           {return true} 
                       else {return false}
               },
               priority: 32
           }
       },
       i18n: {
           en: {
               cantmin: 'You have to select at least %s items from the list'
           },
           es: {
               cantmin: 'Tiene que seleccionar al menos %s items de la lista'
           }
       }
   };
   

来源：https://stackoverflow.com/questions/23635129/select2-validate-and-force-user-to-select-ast-least-x-items