[feature] define after_initialize callback in sequent command

[crypto-zhiming]

Define callback after_initialize in Sequent::Command. We can use this callback to do more things, such as set default value for command attributes.

class AfterInitCommand < Sequent::Command
  attrs flag: Boolean

  after_initialize do
    @flag = true if @flag.nil?
  end
end

[bforma]

I'm not sure if this is the way to go for 'default' values.

We could also introduce the following:

MyCommand < Sequent::Command
  attr flag: Boolean, default: true
end

If you want this with attrs as well, we could try this:

MyCommand < Sequent::Command
  attrs flag: opts(type: Boolean, default: true), other_flag: Boolean
end

[lvonk]

I'm not sure if this is the way to go for 'default' values.

We could also introduce the following:

MyCommand < Sequent::Command
  attr flag: Boolean, default: true
end

I think after_initialize is just another active model callback we can support (like we already do with validations). Using after_initialize also has access to other attributes in the object.

But we could also implement the default suggestion, that is probably more elegant to set default values.