What Does ActiveRecord::MultiparameterAssignmentErrors Mean?

Question

I have a rails form with a datetime_select field. When I try to submit the form, I get the following exception:

ActiveRecord::MultiparameterAssignmentErrors          


        

Answer 1

Like Zubin I've seen this exception when the form submits a month as a month name rather than a numerical month string (eg. October rather than 10).

One user agent I've encountered seems to submit the contents of the option tag rather than the value attribute:

Mozilla/5.0 (SymbianOS/9.2; U; Series60/3.1 NokiaE66-1/300.21.012; Profile/MIDP-2.0 Configuration/CLDC-1.1 ) AppleWebKit/413 (KHTML, like Gecko) Safari/413

So in the case of submitting a multi-parameter date from a helper generated select (from date_select helper) your params will have:

"event"=> {
    "start_on(2i)"=>"October",
    "start_on(3i)"=>"19",
    "start_on(1i)"=>"2010"
}

This creates an exception: ActiveRecord::MultiparameterAssignmentErrors: 1 error(s) on assignment of multiparameter attributes

Most user agents will correctly submit:

"event"=> {
    "start_on(2i)"=>"10",
    "start_on(3i)"=>"19",
    "start_on(1i)"=>"2010"
}