View Source DSL: Reactor.Dsl
reactor
The top-level reactor DSL
Nested DSLs
- middlewares
- middleware
- around
- argument
- wait_for
- collect
- argument
- wait_for
- compose
- argument
- wait_for
- debug
- argument
- wait_for
- flunk
- argument
- wait_for
- group
- argument
- wait_for
- input
- map
- argument
- wait_for
- step
- argument
- wait_for
- switch
matches?
default
Options
Name | Type | Default | Docs |
---|---|---|---|
return | atom | Specify which step result to return upon completion. |
reactor.middlewares
Middleware to be added to the Reactor
Nested DSLs
reactor.middlewares.middleware
middleware module
Name a middleware to be added to the Reactor.
Arguments
Name | Type | Default | Docs |
---|---|---|---|
module | module | The middleware to be added to the Reactor. |
Introspection
Target: Reactor.Dsl.Middleware
reactor.around
around name, fun \\ nil
Wrap a function around a group of steps.
Nested DSLs
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | A unique name for the group of steps. | |
fun | (any, any, any, any -> any) | mfa | The around function. See Reactor.Step.Around for more information. |
Options
Name | Type | Default | Docs |
---|---|---|---|
allow_async? | boolean | false | Whether the emitted steps should be allowed to run asynchronously. |
reactor.around.argument
argument name, source \\ nil
Specifies an argument to a Reactor step.
Each argument is a value which is either the result of another step, or an input value.
Individual arguments can be transformed with an arbitrary function before being passed to any steps.
Examples
argument :name, input(:name)
argument :year, input(:date, [:year])
argument :user, result(:create_user)
argument :user_id, result(:create_user) do
transform & &1.id
end
argument :user_id, result(:create_user, [:id])
argument :three, value(3)
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | The name of the argument which will be used as the key in the arguments map passed to the implementation. | |
source | Reactor.Template.Element | Reactor.Template.Input | Reactor.Template.Result | Reactor.Template.Value | What to use as the source of the argument. See Reactor.Dsl.Argument for more information. |
Options
Name | Type | Default | Docs |
---|---|---|---|
transform | (any -> any) | module | nil | An optional transformation function which can be used to modify the argument before it is passed to the step. |
Introspection
Target: Reactor.Dsl.Argument
reactor.around.wait_for
wait_for names
Wait for the named step to complete before allowing this one to start.
Desugars to argument :_, result(step_to_wait_for)
Examples
wait_for :create_user
Arguments
Name | Type | Default | Docs |
---|---|---|---|
names | atom | list(atom) | The name of the step to wait for. |
Introspection
Target: Reactor.Dsl.WaitFor
Introspection
Target: Reactor.Dsl.Around
reactor.collect
collect name
A Reactor step which simply collects and returns it's arguments.
Arguments can optionally be transformed before returning.
Nested DSLs
Examples
collect :latest_release_uri do
argument :repository, input(:repository)
argument :organisation, input(:organisation)
transform fn inputs ->
%{uri: "https://api.github.com/repos/#{inputs.organisation}/#{inputs.repository}/releases/latest"}
end
end
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | A unique name for the step. Used when choosing the return value of the Reactor and for arguments into other steps. |
Options
Name | Type | Default | Docs |
---|---|---|---|
transform | (any -> any) | module | nil | An optional transformation function which can be used to modify the entire argument map before it is returned. |
reactor.collect.argument
argument name, source \\ nil
Specifies an argument to a Reactor step.
Each argument is a value which is either the result of another step, or an input value.
Individual arguments can be transformed with an arbitrary function before being passed to any steps.
Examples
argument :name, input(:name)
argument :year, input(:date, [:year])
argument :user, result(:create_user)
argument :user_id, result(:create_user) do
transform & &1.id
end
argument :user_id, result(:create_user, [:id])
argument :three, value(3)
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | The name of the argument which will be used as the key in the arguments map passed to the implementation. | |
source | Reactor.Template.Element | Reactor.Template.Input | Reactor.Template.Result | Reactor.Template.Value | What to use as the source of the argument. See Reactor.Dsl.Argument for more information. |
Options
Name | Type | Default | Docs |
---|---|---|---|
transform | (any -> any) | module | nil | An optional transformation function which can be used to modify the argument before it is passed to the step. |
Introspection
Target: Reactor.Dsl.Argument
reactor.collect.wait_for
wait_for names
Wait for the named step to complete before allowing this one to start.
Desugars to argument :_, result(step_to_wait_for)
Examples
wait_for :create_user
Arguments
Name | Type | Default | Docs |
---|---|---|---|
names | atom | list(atom) | The name of the step to wait for. |
Introspection
Target: Reactor.Dsl.WaitFor
Introspection
Target: Reactor.Dsl.Collect
reactor.compose
compose name, reactor
Compose another Reactor into this one.
Allows place another Reactor into this one as if it were a single step.
Nested DSLs
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | A unique name for the step. Allows the result of the composed reactor to be depended upon by steps in this reactor. | |
reactor | Reactor | module | The reactor module or struct to compose upon. |
reactor.compose.argument
argument name, source \\ nil
Specifies an argument to a Reactor step.
Each argument is a value which is either the result of another step, or an input value.
Individual arguments can be transformed with an arbitrary function before being passed to any steps.
Examples
argument :name, input(:name)
argument :year, input(:date, [:year])
argument :user, result(:create_user)
argument :user_id, result(:create_user) do
transform & &1.id
end
argument :user_id, result(:create_user, [:id])
argument :three, value(3)
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | The name of the argument which will be used as the key in the arguments map passed to the implementation. | |
source | Reactor.Template.Element | Reactor.Template.Input | Reactor.Template.Result | Reactor.Template.Value | What to use as the source of the argument. See Reactor.Dsl.Argument for more information. |
Options
Name | Type | Default | Docs |
---|---|---|---|
transform | (any -> any) | module | nil | An optional transformation function which can be used to modify the argument before it is passed to the step. |
Introspection
Target: Reactor.Dsl.Argument
reactor.compose.wait_for
wait_for names
Wait for the named step to complete before allowing this one to start.
Desugars to argument :_, result(step_to_wait_for)
Examples
wait_for :create_user
Arguments
Name | Type | Default | Docs |
---|---|---|---|
names | atom | list(atom) | The name of the step to wait for. |
Introspection
Target: Reactor.Dsl.WaitFor
Introspection
Target: Reactor.Dsl.Compose
reactor.debug
debug name
Inserts a step which will send debug information to the Logger
.
Nested DSLs
Examples
debug :debug do
argument :suss, result(:suss_step)
end
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | A unique identifier for the step. |
Options
Name | Type | Default | Docs |
---|---|---|---|
level | :emergency | :alert | :critical | :error | :warning | :notice | :info | :debug | :debug | The log level to send the debug information to. |
reactor.debug.argument
argument name, source \\ nil
Specifies an argument to a Reactor step.
Each argument is a value which is either the result of another step, or an input value.
Individual arguments can be transformed with an arbitrary function before being passed to any steps.
Examples
argument :name, input(:name)
argument :year, input(:date, [:year])
argument :user, result(:create_user)
argument :user_id, result(:create_user) do
transform & &1.id
end
argument :user_id, result(:create_user, [:id])
argument :three, value(3)
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | The name of the argument which will be used as the key in the arguments map passed to the implementation. | |
source | Reactor.Template.Element | Reactor.Template.Input | Reactor.Template.Result | Reactor.Template.Value | What to use as the source of the argument. See Reactor.Dsl.Argument for more information. |
Options
Name | Type | Default | Docs |
---|---|---|---|
transform | (any -> any) | module | nil | An optional transformation function which can be used to modify the argument before it is passed to the step. |
Introspection
Target: Reactor.Dsl.Argument
reactor.debug.wait_for
wait_for names
Wait for the named step to complete before allowing this one to start.
Desugars to argument :_, result(step_to_wait_for)
Examples
wait_for :create_user
Arguments
Name | Type | Default | Docs |
---|---|---|---|
names | atom | list(atom) | The name of the step to wait for. |
Introspection
Target: Reactor.Dsl.WaitFor
Introspection
Target: Reactor.Dsl.Debug
reactor.flunk
flunk name, message
Creates a step which will always cause the Reactor to exit with an error.
This step will flunk with a Reactor.Error.Invalid.ForcedFailureError
with it's message set to the provided message.
Additionally, any arguments to the step will be stored in the exception under the arguments
key.
Nested DSLs
Examples
flunk :outaroad, "Ran out of road before reaching 88Mph"
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | A unique name for the step. Used when choosing the return value of the Reactor and for arguments into other steps. | |
message | nil | String.t | Reactor.Template.Element | Reactor.Template.Input | Reactor.Template.Result | Reactor.Template.Value | The message to to attach to the exception. |
reactor.flunk.argument
argument name, source \\ nil
Specifies an argument to a Reactor step.
Each argument is a value which is either the result of another step, or an input value.
Individual arguments can be transformed with an arbitrary function before being passed to any steps.
Examples
argument :name, input(:name)
argument :year, input(:date, [:year])
argument :user, result(:create_user)
argument :user_id, result(:create_user) do
transform & &1.id
end
argument :user_id, result(:create_user, [:id])
argument :three, value(3)
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | The name of the argument which will be used as the key in the arguments map passed to the implementation. | |
source | Reactor.Template.Element | Reactor.Template.Input | Reactor.Template.Result | Reactor.Template.Value | What to use as the source of the argument. See Reactor.Dsl.Argument for more information. |
Options
Name | Type | Default | Docs |
---|---|---|---|
transform | (any -> any) | module | nil | An optional transformation function which can be used to modify the argument before it is passed to the step. |
Introspection
Target: Reactor.Dsl.Argument
reactor.flunk.wait_for
wait_for names
Wait for the named step to complete before allowing this one to start.
Desugars to argument :_, result(step_to_wait_for)
Examples
wait_for :create_user
Arguments
Name | Type | Default | Docs |
---|---|---|---|
names | atom | list(atom) | The name of the step to wait for. |
Introspection
Target: Reactor.Dsl.WaitFor
Introspection
Target: Reactor.Dsl.Flunk
reactor.group
group name
Call functions before and after a group of steps.
Nested DSLs
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | A unique name for the group of steps. |
Options
Name | Type | Default | Docs |
---|---|---|---|
before_all | (any, any, any -> any) | mfa | The before function. See Reactor.Step.Group for more information. | |
after_all | (any -> any) | mfa | The after function. See Reactor.Step.Group for more information. | |
allow_async? | boolean | true | Whether the emitted steps should be allowed to run asynchronously. |
reactor.group.argument
argument name, source \\ nil
Specifies an argument to a Reactor step.
Each argument is a value which is either the result of another step, or an input value.
Individual arguments can be transformed with an arbitrary function before being passed to any steps.
Examples
argument :name, input(:name)
argument :year, input(:date, [:year])
argument :user, result(:create_user)
argument :user_id, result(:create_user) do
transform & &1.id
end
argument :user_id, result(:create_user, [:id])
argument :three, value(3)
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | The name of the argument which will be used as the key in the arguments map passed to the implementation. | |
source | Reactor.Template.Element | Reactor.Template.Input | Reactor.Template.Result | Reactor.Template.Value | What to use as the source of the argument. See Reactor.Dsl.Argument for more information. |
Options
Name | Type | Default | Docs |
---|---|---|---|
transform | (any -> any) | module | nil | An optional transformation function which can be used to modify the argument before it is passed to the step. |
Introspection
Target: Reactor.Dsl.Argument
reactor.group.wait_for
wait_for names
Wait for the named step to complete before allowing this one to start.
Desugars to argument :_, result(step_to_wait_for)
Examples
wait_for :create_user
Arguments
Name | Type | Default | Docs |
---|---|---|---|
names | atom | list(atom) | The name of the step to wait for. |
Introspection
Target: Reactor.Dsl.WaitFor
Introspection
Target: Reactor.Dsl.Group
reactor.input
input name
Specifies an input to the Reactor.
An input is a value passed in to the Reactor when executing. If a Reactor were a function, these would be it's arguments.
Inputs can be transformed with an arbitrary function before being passed to any steps.
Examples
input :name
input :age do
transform &String.to_integer/1
end
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | A unique name for this input. Used to allow steps to depend on it. |
Options
Name | Type | Default | Docs |
---|---|---|---|
transform | (any -> any) | module | nil | An optional transformation function which can be used to modify the input before it is passed to any steps. |
Introspection
Target: Reactor.Dsl.Input
reactor.map
map name
Execute nested steps for every item of an iterator.
Allows you to "map over" a collection applying a some steps to each element, returning a list of new values. The input collection must be bounded - ie you cannot pass infinite streams into this step or it will just loop forever - and because it has to keep the results from each batch will eventually just use up all available RAM.
Under the hood we use Iter
to handle lazy iteration of the collection. This
means that you can pass an Iter.t
or any value for which Iter.IntoIterable
is implemented.
A note on ordering
If your application doesn't need the results back in the same order that they were provided then setting
strict_ordering?
tofalse
will increase performance - especially on large input sets.
Nested DSLs
Examples
map :double_numbers do
input input(:numbers)
step :double do
argument :number, element(:double_numbers)
run %{number: number}, _, _ ->
{:ok, number * 2}
end
end
end
step :get_subscriptions do
run _, _, _ ->
Stripe.Subscription.list()
end
end
map :cancel_subscriptions do
input result(:get_subscriptions)
step :cancel do
argument :sub_id, element(:cancel_subscriptions, [:id])
run fn args, _, _ ->
Stripe.Subscription.cancel(arg.sub_id, %{prorate: true, invoice_now: true})
end
end
return :cancel
end
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | A unique name for the step. |
Options
Name | Type | Default | Docs |
---|---|---|---|
source | Reactor.Template.Element | Reactor.Template.Input | Reactor.Template.Result | Reactor.Template.Value | The iterator or enumerable to use as the source of the iteration. | |
allow_async? | boolean | false | Whether the emitted steps should be allowed to run asynchronously. |
batch_size | pos_integer | 100 | The number of items to consume off the source when emitting steps. |
return | atom | The name of the nested step to use as the return value. | |
strict_ordering? | boolean | true | Whether the mapped values must be returned in the same order that they were provided. |
reactor.map.argument
argument name, source \\ nil
Specifies an argument to a Reactor step.
Each argument is a value which is either the result of another step, or an input value.
Individual arguments can be transformed with an arbitrary function before being passed to any steps.
Examples
argument :name, input(:name)
argument :year, input(:date, [:year])
argument :user, result(:create_user)
argument :user_id, result(:create_user) do
transform & &1.id
end
argument :user_id, result(:create_user, [:id])
argument :three, value(3)
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | The name of the argument which will be used as the key in the arguments map passed to the implementation. | |
source | Reactor.Template.Element | Reactor.Template.Input | Reactor.Template.Result | Reactor.Template.Value | What to use as the source of the argument. See Reactor.Dsl.Argument for more information. |
Options
Name | Type | Default | Docs |
---|---|---|---|
transform | (any -> any) | module | nil | An optional transformation function which can be used to modify the argument before it is passed to the step. |
Introspection
Target: Reactor.Dsl.Argument
reactor.map.wait_for
wait_for names
Wait for the named step to complete before allowing this one to start.
Desugars to argument :_, result(step_to_wait_for)
Examples
wait_for :create_user
Arguments
Name | Type | Default | Docs |
---|---|---|---|
names | atom | list(atom) | The name of the step to wait for. |
Introspection
Target: Reactor.Dsl.WaitFor
Introspection
Target: Reactor.Dsl.Map
reactor.step
step name, impl \\ nil
Specifies a Reactor step.
Steps are the unit of work in a Reactor. Reactor will calculate the dependencies graph between the steps and execute as many as it can in each iteration.
See the Reactor.Step
behaviour for more information.
Nested DSLs
Examples
step :create_user, MyApp.Steps.CreateUser do
argument :username, input(:username)
argument :password_hash, result(:hash_password)
end
step :hash_password do
argument :password, input(:password)
run fn %{password: password}, _ ->
{:ok, Bcrypt.hash_pwd_salt(password)}
end
end
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | A unique name for the step. Used when choosing the return value of the Reactor and for arguments into other steps. | |
impl | module | nil | A module that implements the Reactor.Step behaviour that provides the implementation. |
Options
Name | Type | Default | Docs |
---|---|---|---|
run | (any -> any) | mfa | (any, any -> any) | mfa | Provide an anonymous function which implements the run/3 callback. Cannot be provided at the same time as the impl argument. | |
undo | (any -> any) | mfa | (any, any -> any) | mfa | (any, any, any -> any) | mfa | Provide an anonymous function which implements the undo/4 callback. Cannot be provided at the same time as the impl argument. | |
compensate | (any -> any) | mfa | (any, any -> any) | mfa | (any, any, any -> any) | mfa | Provide an anonymous function which implements the undo/4 callback. Cannot be provided at the same time as the impl argument. | |
max_retries | :infinity | non_neg_integer | :infinity | The maximum number of times that the step can be retried before failing. Only used when the result of the compensate/4 callback is :retry . |
async? | boolean | true | When set to true the step will be executed asynchronously via Reactor's TaskSupervisor . |
transform | (any -> any) | module | nil | An optional transformation function which can be used to modify the entire argument map before it is passed to the step. |
reactor.step.argument
argument name, source \\ nil
Specifies an argument to a Reactor step.
Each argument is a value which is either the result of another step, or an input value.
Individual arguments can be transformed with an arbitrary function before being passed to any steps.
Examples
argument :name, input(:name)
argument :year, input(:date, [:year])
argument :user, result(:create_user)
argument :user_id, result(:create_user) do
transform & &1.id
end
argument :user_id, result(:create_user, [:id])
argument :three, value(3)
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | The name of the argument which will be used as the key in the arguments map passed to the implementation. | |
source | Reactor.Template.Element | Reactor.Template.Input | Reactor.Template.Result | Reactor.Template.Value | What to use as the source of the argument. See Reactor.Dsl.Argument for more information. |
Options
Name | Type | Default | Docs |
---|---|---|---|
transform | (any -> any) | module | nil | An optional transformation function which can be used to modify the argument before it is passed to the step. |
Introspection
Target: Reactor.Dsl.Argument
reactor.step.wait_for
wait_for names
Wait for the named step to complete before allowing this one to start.
Desugars to argument :_, result(step_to_wait_for)
Examples
wait_for :create_user
Arguments
Name | Type | Default | Docs |
---|---|---|---|
names | atom | list(atom) | The name of the step to wait for. |
Introspection
Target: Reactor.Dsl.WaitFor
Introspection
Target: Reactor.Dsl.Step
reactor.switch
switch name
Use a predicate to determine which steps should be executed.
Nested DSLs
Arguments
Name | Type | Default | Docs |
---|---|---|---|
name | atom | A unique name for the switch. |
Options
Name | Type | Default | Docs |
---|---|---|---|
on | Reactor.Template.Element | Reactor.Template.Input | Reactor.Template.Result | Reactor.Template.Value | The value to match against. | |
allow_async? | boolean | true | Whether the emitted steps should be allowed to run asynchronously. |
reactor.switch.matches?
matches? predicate
A group of steps to run when the predicate matches.
Arguments
Name | Type | Default | Docs |
---|---|---|---|
predicate | (any -> any) | mfa | A one-arity function which is used to match the switch input. If the switch returns a truthy value, then the nested steps will be run. |
Options
Name | Type | Default | Docs |
---|---|---|---|
allow_async? | boolean | true | Whether the emitted steps should be allowed to run asynchronously. |
return | atom | Specify which step result to return upon completion. |
Introspection
Target: Reactor.Dsl.Switch.Match
reactor.switch.default
If none of the matches?
branches match the input, then the default
steps will be run if provided.
Options
Name | Type | Default | Docs |
---|---|---|---|
return | atom | Specify which step result to return upon completion. |
Introspection
Target: Reactor.Dsl.Switch.Default
Introspection
Target: Reactor.Dsl.Switch