activerecord - after_find callback does not work properly -

activerecord - after_find callback does not work properly -

i have rails 4.1.6 installed.

model report:

after_find :convert_decimal_to_float def convert_decimal_to_float self.mag = self.mag.to_f end

in rails console:

2.1.2 :001 > r = report.last ... 2.1.2 :002 > r.mag => #<bigdecimal:5032730,'0.31e1',18(36)>

but if utilize r.mag.to_f, works fine:

2.1.2 :003 > r.mag.to_f => 3.1

the question is, why doesn't after_find callback work here?

your after_find callback working because database column of type decimal save bigdecimal. if column of type float if tried save bigdecimal number it, convert , save floating point number.

without knowing why require conversion upon "finding" object, hard give advice appropriate workaround here couple of options:

first option:

you can create 2 columns in database. decimal column , float column.

migration

add_column('report','mag', :decimal,:precision => 11, :scale => 9) # i've used random precision , scale, i'm not sure need add_column('report','mag_floating_point', :float)

report model

after_find :convert_decimal_to_float def convert_decimal_to_float self.mag_floating_point = self.mag # convert decimal number float , "assign" self.save # still need save object value has been assigned end

second option:

the sec alternative think alot better.

report model

attr_accessor :mag_floating_point # virtual attribute def convert_decimal_to_float self.mag_floating_point = self.mag.to_f end

you able access floating point through virtual attribute maintain in mind wont persist. in opinion, much cleaner.

activerecord ruby-on-rails-4