# `Diffo.Provider.Changes.Define`
[🔗](https://github.com/diffo-dev/diffo/blob/v0.9.0/lib/diffo/provider/changes/define.ex#L5)

After-action change for the standard `:define` pattern.

Applies `characteristic_value_updates` to the instance's declared typed and
dynamic characteristics (`Characteristic.update_all/3`) and to its declared
pools (`Pool.update_pools/3`), then reloads the result via the resource's
primary `:read` action.

## Usage

    update :define do
      argument :characteristic_value_updates, {:array, :term}
      change Diffo.Provider.Changes.Define
    end

This replaces the hand-written `after_action` block that threads
`characteristics()`, `pools()`, `Characteristic.update_all/3` and
`Pool.update_pools/3` together on every consumer.

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*Consult [api-reference.md](api-reference.md) for complete listing*