View Source Alembic.Filter behaviour (alembic v0.1.0)

Behaviour for custom Alembic filters.

config :alembic, :custom_filters, [MyApp.Filters.Money]

Each module implements both callbacks: name/0 is the filter name as invoked in templates ({{ value | my_filter }}), and apply/2 performs the transformation. name/0 is a small addition beyond what the issue's own sketch showed (just apply/2) — without it, a list of modules alone gives Alembic.Filters no way to map a template's filter name string back to the module that should handle it.

Summary

Callbacks

apply(value, args)

Transforms value given the filter's (already-evaluated) args.

name()

The filter name as it appears in a template's pipe chain, e.g. "money" for {{ price | money }}.

Callbacks

apply(value, args)

@callback apply(value :: any(), args :: [any()]) ::
  {:ok, any()} | {:error, reason :: any()}

Transforms value given the filter's (already-evaluated) args.

name()

@callback name() :: String.t()

The filter name as it appears in a template's pipe chain, e.g. "money" for {{ price | money }}.