cheat sheets.

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Cheat Sheet:
validate - define it with a custom validation to run on all saves validate_on_create - define it with a custom validation to run on all creates validate_on_update - define it with a custom validation to run on all updates All validation helpers can take :if, :on, and :message unless otherwise stated. validates_acceptance_of(:attribute, :value) - validates that the gived attribute is set to "1" or the passed value. Does not have to be a database attribute. validates_associated(*attributes) - validates whether the associated object or objects are all valid themselves. works with any kind of association. does not take message validates_confirmation_of(:attribute) - validates that attributename_confirmation is equal to the attribute. The confirmation variable does not need to be in the database validates_exclusion_of(:attribute, :if) - validates that the value of the specified attribute is not in a particular enumerable object specified by the :if argument validates_format_of(:attribute, :with) - validates whether the value of the specified attribute is of the correct form by matching it against the regular expression provided in the :with argument validates_inclusion_of(:attribute, :if) - validates that the value of the specified attribute is in a particular enumerable object specified by the :if argument validates_length_of(:attribute, *options) - validates that the specified attribute matches the length restrictions supplied. only one option can be used at a time. options: maximum, minimum, is, within, in, allow_nil. message options: too_long, too_short, wrong_length validates_numericality_of(:attribute) - validates whether the value of the specified attribute is numeric by trying to convert it to a float with Kernel.Float (if integer is false) or applying it to the regular expression /^[+\-]?\d+$/ (if integer is set to true). options: allow_nil, only_integer validates_presence_of(:atrribute) - validates that the specified attributes are not blank (as defined by Object#blank?) validates_uniqueness_of(:attribute) = calidates whether the value of the specified attributes are unique across the system. options: scope (one or more columns by which to limit the scope of the uniquness constraint_

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