Class: Easyop::FlowBuilder

Inherits:
Object
  • Object
show all
Defined in:
lib/easyop/flow_builder.rb

Overview

FlowBuilder accumulates callbacks before executing a flow. Returned by FlowClass.flow (no args) and FlowClass.result.

Usage:

ProcessCheckout.flow
  .on_success { |ctx| redirect_to order_path(ctx.order) }
  .on_failure { |ctx| flash[:error] = ctx.error; redirect_back }
  .call(user: current_user, cart: current_cart)

# With bound object (e.g. a Rails controller):
ProcessCheckout.flow
  .bind_with(self)
  .on(success: :redirect_to_dashboard, fail: :render_form)
  .call(user: current_user, cart: current_cart)

Instance Method Summary collapse

Constructor Details

#initialize(flow_class) ⇒ FlowBuilder

Returns a new instance of FlowBuilder.



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# File 'lib/easyop/flow_builder.rb', line 17

def initialize(flow_class)
  @flow_class        = flow_class
  @success_callbacks = []
  @failure_callbacks = []
  @bound_object      = nil
end

Instance Method Details

#bind_with(obj) ⇒ Object

Bind a context object for use with symbol shortcuts in ‘.on(…)`. Typically `self` in a Rails controller.



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# File 'lib/easyop/flow_builder.rb', line 38

def bind_with(obj)
  @bound_object = obj
  self
end

#call(attrs = {}) ⇒ Object

Execute the flow with the given attributes, then fire the registered callbacks. Returns the ctx (Easyop::Ctx).



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# File 'lib/easyop/flow_builder.rb', line 62

def call(attrs = {})
  ctx = @flow_class.call(attrs)
  callbacks = ctx.success? ? @success_callbacks : @failure_callbacks
  callbacks.each { |cb| cb.call(ctx) }
  ctx
end

#on(success: nil, fail: nil) ⇒ Object

Register named-method callbacks. Requires bind_with to have been called when the methods live on another object.

.on(success: :redirect_to_dashboard, fail: :render_form)



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# File 'lib/easyop/flow_builder.rb', line 47

def on(success: nil, fail: nil)
  bound = @bound_object
  if success
    success_name = success
    @success_callbacks << ->(ctx) { _invoke_named(bound, success_name, ctx) }
  end
  if fail
    fail_name = fail
    @failure_callbacks << ->(ctx) { _invoke_named(bound, fail_name, ctx) }
  end
  self
end

#on_failure(&block) ⇒ Object

Register a callback to run when the flow fails.



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# File 'lib/easyop/flow_builder.rb', line 31

def on_failure(&block)
  @failure_callbacks << block
  self
end

#on_success(&block) ⇒ Object

Register a callback to run when the flow succeeds.



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# File 'lib/easyop/flow_builder.rb', line 25

def on_success(&block)
  @success_callbacks << block
  self
end