Type Composition

Zodra types can reference each other, contain arrays, and derive from existing types.

References

Embed one type inside another:

Zodra.type :line_item do
  uuid :id
  reference :product       # embeds the :product type
  integer :quantity, min: 1
end

Specify a different type name with to::

reference :billing_address, to: :address

Arrays

Define array fields with of::

Zodra.type :order do
  uuid :id
  array :line_items, of: :line_item   # array of :line_item objects
  array :tags, of: :string            # array of strings
end

Type derivation with `from`

Create new types based on existing ones. This avoids duplicating field definitions:

app/types/customer_summary.rb

Zodra.type :customer_summary, from: :customer, pick: %i[id name email]

`pick` — include only specific fields

Zodra.type :product_card, from: :product, pick: %i[id name price]

`omit` — exclude specific fields

Zodra.type :customer_input, from: :customer, omit: %i[id created_at updated_at]

`partial` — make all fields optional

Zodra.type :customer_patch, from: :customer, omit: %i[id], partial: true

Combining `from` with a block

Add or override fields on a derived type:

Zodra.type :order_input, from: :order, omit: %i[id status total_amount] do
  array :items, of: :order_item_input
end

Using `from` inside a type block

You can also call from inside the block to merge fields from another type:

Zodra.type :detailed_product do
  from :product
  string :long_description
  array :reviews, of: :review
end

Contracts with `from`

Type derivation works the same way in contract params:

Zodra.contract :customers do
  action :create do
    params from: :customer, omit: %i[id registered_at created_at updated_at]
    response :customer
  end

  action :update do
    params from: :customer, omit: %i[id registered_at created_at updated_at], partial: true
    response :customer
  end
end

Type Composition

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