defmodule Ash.Flow do
@moduledoc """
A flow is a static definition of a set of steps to be run.
See the [guide](/documentation/topics/flows.md) for more.
"""
@type t :: module
use Spark.Dsl,
default_extensions: [
extensions: [Ash.Flow.Dsl]
]
require Ash.Tracer
defdelegate element_refs(input), to: Ash.Flow.Template
@spec run!(any, any, Keyword.t()) :: Ash.Flow.Result.t() | no_return()
def run!(flow, input, opts \\ []) do
case run(flow, input, opts) do
%Ash.Flow.Result{valid?: true} = result ->
result
%Ash.Flow.Result{errors: errors} ->
raise Ash.Error.to_error_class(errors)
end
end
@spec run(any, any, Keyword.t()) :: Ash.Flow.Result.t()
def run(flow, input, opts \\ []) do
params = input
executor = opts[:executor] || Ash.Flow.Executor.AshEngine
opts =
opts
|> add_actor()
|> add_tenant()
|> add_tracer()
Ash.Tracer.span :flow, Ash.Flow.Info.trace_name(flow), opts[:tracer] do
Ash.Tracer.telemetry_span [:ash, :flow], %{
flow_short_name: Ash.Flow.Info.short_name(flow)
} do
with {:ok, input} <- cast_input(flow, input),
{:ok, built} <- executor.build(flow, input, opts) do
case executor.execute(built, input, opts) do
{:ok, result, metadata} ->
%Ash.Flow.Result{
flow: flow,
params: params,
input: input,
result: result,
notifications: metadata[:notifications] || [],
valid?: true,
complete?: true
}
{:ok, result} ->
%Ash.Flow.Result{
flow: flow,
params: params,
input: input,
result: result,
valid?: true,
complete?: true
}
{:error, metadata, error} ->
complete? = complete?(error)
%Ash.Flow.Result{
flow: flow,
params: params,
input: input,
notifications: metadata[:notifications] || [],
runner_metadata: if(not complete?, do: metadata[:runner_metadata]),
valid?: false,
complete?: complete?,
errors: List.wrap(error)
}
{:error, error} ->
%Ash.Flow.Result{
flow: flow,
params: params,
input: input,
valid?: false,
complete?: complete?(error),
errors: List.wrap(error)
}
end
else
{:error, new_input, error} ->
%Ash.Flow.Result{
flow: flow,
params: input,
input: new_input,
valid?: false,
complete?: complete?(error),
errors: List.wrap(error)
}
{:error, error} ->
%Ash.Flow.Result{
flow: flow,
params: input,
input: input,
valid?: false,
complete?: complete?(error),
errors: List.wrap(error)
}
end
end
end
end
defp complete?(%Ash.Error.Flow.Halted{}) do
false
end
defp complete?(_) do
true
end
defp add_actor(opts) do
if Keyword.has_key?(opts, :actor) do
opts
else
case Process.get(:ash_actor) do
{:actor, value} ->
Keyword.put(opts, :actor, value)
_ ->
opts
end
end
end
defp add_tenant(opts) do
if Keyword.has_key?(opts, :actor) do
opts
else
case Process.get(:ash_tenant) do
{:tenant, value} ->
Keyword.put(opts, :tenant, value)
_ ->
opts
end
end
end
defp add_tracer(opts) do
if Keyword.has_key?(opts, :tracer) do
opts
else
case Process.get(:ash_tracer) do
{:tracer, value} ->
Keyword.put(opts, :tracer, value || Application.get_env(:ash, :tracer))
_ ->
Keyword.put(opts, :tracer, Application.get_env(:ash, :tracer))
end
end
end
defp cast_input(flow, params) do
arguments = Ash.Flow.Info.arguments(flow)
Enum.reduce_while(arguments, {:ok, %{}}, fn arg, {:ok, acc} ->
value =
case Map.fetch(params, arg.name) do
:error ->
Map.fetch(params, to_string(arg.name))
other ->
other
end
case value do
:error ->
if is_nil(arg.default) do
{:cont, {:ok, acc}}
else
value =
case arg.default do
{m, f, a} ->
apply(m, f, a)
fun when is_function(fun, 0) ->
fun.()
value ->
value
end
{:cont, {:ok, Map.put(acc, arg.name, value)}}
end
{:ok, value} ->
with {:ok, value} <-
Ash.Type.Helpers.cast_input(arg.type, value, arg.constraints, flow),
{:constrained, {:ok, casted}}
when not is_nil(value) <-
{:constrained, Ash.Type.apply_constraints(arg.type, value, arg.constraints)} do
{:cont, {:ok, Map.put(acc, arg.name, casted)}}
else
{:constrained, {:ok, nil}} ->
{:cont, {:ok, Map.put(acc, arg.name, nil)}}
{:constrained, {:error, error}} ->
{:halt, {:error, acc, error}}
{:error, error} ->
{:halt, {:error, acc, error}}
end
end
end)
end
@doc false
# sobelow_skip ["DOS.StringToAtom"]
@impl Spark.Dsl
def handle_before_compile(_opts) do
quote bind_quoted: [] do
{opt_args, args} =
__MODULE__
|> Ash.Flow.Info.arguments()
|> Enum.split_with(&(&1.allow_nil? || !is_nil(&1.default)))
args = Enum.map(args, & &1.name)
opt_args = Enum.map(opt_args, & &1.name)
arg_vars = Enum.map(args, &{&1, [], Elixir})
@doc Ash.Flow.Info.description(__MODULE__)
def run!(unquote_splicing(arg_vars), input \\ %{}, opts \\ []) do
{input, opts} =
if opts == [] && Keyword.keyword?(input) do
{%{}, input}
else
{input, opts}
end
opt_input =
Enum.reduce(unquote(opt_args), input, fn opt_arg, input ->
case Map.fetch(input, opt_arg) do
{:ok, val} ->
Map.put(input, opt_arg, val)
:error ->
case Map.fetch(input, to_string(opt_arg)) do
{:ok, val} ->
Map.put(input, opt_arg, val)
:error ->
input
end
end
end)
required_input =
unquote(args)
|> Enum.zip([unquote_splicing(arg_vars)])
|> Map.new()
all_input = Map.merge(required_input, opt_input)
Ash.Flow.run!(__MODULE__, all_input, opts)
end
def run(unquote_splicing(arg_vars), input \\ %{}, opts \\ []) do
{input, opts} =
if opts == [] && Keyword.keyword?(input) do
{%{}, input}
else
{input, opts}
end
opt_input =
Enum.reduce(unquote(opt_args), input, fn opt_arg, input ->
case Map.fetch(input, opt_arg) do
{:ok, val} ->
Map.put(input, opt_arg, val)
:error ->
case Map.fetch(input, to_string(opt_arg)) do
{:ok, val} ->
Map.put(input, opt_arg, val)
:error ->
input
end
end
end)
required_input =
unquote(args)
|> Enum.zip([unquote_splicing(arg_vars)])
|> Map.new()
all_input = Map.merge(required_input, opt_input)
Ash.Flow.run(__MODULE__, all_input, opts)
end
@default_short_name __MODULE__
|> Module.split()
|> Enum.reverse()
|> Enum.take(2)
|> Enum.reverse()
|> Enum.map_join("_", &Macro.underscore/1)
|> String.to_atom()
def default_short_name do
@default_short_name
end
end
end
def handle_modifiers(action_input) do
do_handle_modifiers(action_input)
end
defp do_handle_modifiers(action_input)
when is_map(action_input) and not is_struct(action_input) do
Map.new(action_input, fn {key, value} ->
new_key = do_handle_modifiers(key)
new_val = do_handle_modifiers(value)
{new_key, new_val}
end)
end
defp do_handle_modifiers(action_input) when is_list(action_input) do
Enum.map(action_input, &do_handle_modifiers(&1))
end
defp do_handle_modifiers({:_path, value, path}) do
do_get_in(do_handle_modifiers(value), path)
end
defp do_handle_modifiers({:_expr, expr}) do
case Ash.Filter.hydrate_refs(expr, %{
resource: nil,
aggregates: %{},
calculations: %{},
public?: false
}) do
{:ok, hydrated} ->
case Ash.Expr.eval_hydrated(hydrated) do
{:ok, result} ->
result
:unknown ->
raise """
Expression #{inspect(expr)} could not be evaluated in the context of the flow
"""
{:error, error} ->
raise Ash.Error.to_error_class(error)
end
{:error, error} ->
raise Ash.Error.to_error_class(error)
end
end
defp do_handle_modifiers(action_input) when is_tuple(action_input) do
List.to_tuple(do_handle_modifiers(Tuple.to_list(action_input)))
end
defp do_handle_modifiers(other), do: other
@doc false
def do_get_in(value, []), do: value
def do_get_in(value, [key | rest]) when is_atom(key) and is_struct(value) do
do_get_in(Map.get(value, key), rest)
end
def do_get_in(value, [key | rest]) do
do_get_in(get_in(value, [key]), rest)
end
def do_fetch_in(value, []), do: {:ok, value}
def do_fetch_in(value, [key | rest]) when is_atom(key) and is_struct(value) do
case Map.fetch(value, key) do
{:ok, value} ->
do_fetch_in(value, rest)
:error ->
:error
end
end
def do_fetch_in(value, [key | rest]) when is_map(value) do
case Map.fetch(value, key) do
{:ok, result} ->
do_fetch_in(result, rest)
:error ->
:error
end
end
def do_fetch_in(_, _), do: :error
@impl Spark.Dsl
def explain(dsl_state, _) do
Ash.Flow.Info.description(dsl_state)
end
end
