Newbie validation

hi there. Here is the simple scenario:

My active record connects to a table that contains an integer field.

My form contains a text box that allows me to enter a value to get
updated to the integer field.

If anything gets entered that is anything other than a POSITIVE INTEGER,
I want to display an error.

I have noticed that if I create a new active record like
@record =[:number])

and the number is a float, say 4.06, this will get rounded in the Active
Record if i display it at this point
render_text @record.number …will show 4

Because it will get rounded automatically, I can’t tell that it is a
non-integer number from within the active record and display an error.

Also, if after submitting the form, the active record will contain the
rounded value (4) but on return to the form, the text field will contain
the original value submitted, 4.06.

How can I intervene this behaviour, ie, test weather the value submitted
is an INTEGER and return an error if it is not (including decimal

Hi, I would recommend adding the following to your controller:

validates_numericality_of :my_positive_integer, :gte => 0, :only_integer

Also, I would recommending getting and reading “Agile Web D.

Good luck,


Thanks for the solution, so simple.

I have actually read the agile book (most of it), but
i’m wondering if there is a reference where I can self
discover all the various switches to these methods,

for example the gte in validates_numericality_of. I couldn’t see
this option in the online api reference.

Thanks for the help.

Hey Monty, if you would like to use the string “:gte => 0”, you’ll have
download and install the following plugin:

Otherwise, the following should work for you:

validates_numericality_of :name, :only_integer => true
validates_format_of :name, :with => /^([0-9]+)$/, :on => :create,
:on => :update

Finally, you would add that validation line to your model file instead
of your controller.

Good luck,


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