Nested Data
dry-validation supports validation of nested data, this includes both hashes and arrays as the validation input.
Nested Hash
To define validation rules for a nested hash you can use the same DSL on a specific key:
require 'dry-validation'
schema = Dry::Validation.Schema do
required(:address).schema do
required(:city).filled(min_size?: 3)
required(:street).filled
required(:country).schema do
required(:name).filled
required(:code).filled
end
end
end
errors = schema.call({}).errors
puts errors.inspect
# { :address => ["is missing"] }
errors = schema.call(address: { city: 'NYC' }).errors
puts errors.to_h.inspect
# {
# :address => [
# { :street => ["is missing"] },
# { :country => ["is missing"] }
# ]
# }
Nested Maybe Hash
If a nested hash could be nil, simply use maybe macro with a block:
require 'dry-validation'
schema = Dry::Validation.Schema do
required(:address).maybe do
schema do
required(:city).filled(min_size?: 3)
required(:street).filled
required(:country).schema do
required(:name).filled
required(:code).filled
end
end
end
end
schema.(address: nil).success? # true
Nested Array
You can use the each macro for validating each element in an array:
schema = Dry::Validation.Schema do
required(:phone_numbers).each(:str?)
end
errors = schema.call(phone_numbers: '').messages
puts errors.inspect
# { :phone_numbers => ["must be an array"] }
errors = schema.call(phone_numbers: ['123456789', 123456789]).messages
puts errors.inspect
# {
# :phone_numbers => {
# 1 => ["must be a string"]
# }
# }
Similarly, you use each and schema to validate an array of hashes:
schema = Dry::Validation.Schema do
required(:people).each do
schema do
required(:name).filled(:str?)
required(:age).filled(:int?, gteq?: 18)
end
end
end
errors = schema.call(
people: [ { name: 'Alice', age: 19 }, { name: 'Bob', age: 17 } ],
).messages
errors = schema.call(phone_numbers: ['123456789', 123456789]).messages
puts errors.inspect
# => {
# :people=>{
# 1=>{
# :age=>["must be greater than or equal to 18"]
# }
# }
# }