Blueprint API Updating/Creating Consistency

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TL;DR

Blueprint initial creation should behave the same way as the blueprint updating.

What?

Currently, the on_player_setup_blueprint event behaves differently when the blueprint is created normal way, when it's created without confirmation, and/or when it's updated.

Event Handler Example

From Miniloader mod:

Code: Select all

function M.get_blueprint_to_setup(player_index)
  local player = game.players[player_index]

  -- normal drag-select
  local blueprint_to_setup = player.blueprint_to_setup
  if blueprint_to_setup
  and blueprint_to_setup.valid_for_read
  and blueprint_to_setup.is_blueprint_setup() then
    return blueprint_to_setup
  end

  -- alt drag-select (skips configuration dialog)
  local cursor_stack = player.cursor_stack
  if cursor_stack
  and cursor_stack.valid_for_read
  and cursor_stack.is_blueprint
  and cursor_stack.is_blueprint_setup() then
    local bp = cursor_stack
    while bp.is_blueprint_book do
      bp = bp.get_inventory(defines.inventory.item_main)[bp.active_index]
    end
    return bp
  end

  -- update of existing blueprint
  local opened_blueprint = global.previous_opened_blueprint_for[player_index]
  if  opened_blueprint
  and opened_blueprint.tick == game.tick
  and opened_blueprint.blueprint
  and opened_blueprint.blueprint.valid_for_read
  and opened_blueprint.blueprint.is_blueprint_setup() then
    return opened_blueprint.blueprint
  end
end

As you can see in the example above, all cases are handled by different branches which are executed each time a player selects a blueprint, and handling the update even requires listening on the on_gui_closed event which should have nothing to do with the blueprints.

Possible solutions:

1. Provide the modifiable blueprint entity for the event payload
2. Provide a new event, on_entity_blueprinted, which is invoked when a specific entity (usually, by prototype ID) is blueprinted by either way

Why?

Quite often I can see that some modded entities either explicitly or implicitly don't work on updated blueprints.

Some Examples

• Display Plates explicitly state mod "can be used with blueprints, (except updating blueprints)"
• Compact Circuits mod supports blueprint creating & updating but not when a blueprint is updated inside the blueprint book (see: issue discussion)
• Editor Extensions mod's Infinity Wagons (and some other entities) lose their filters when the blueprint is updated (see: GH issue)
• Miniloaders & AAI Signal Transmission
  mods have some undocumented problems with the updating a blueprint.

Since the point of the 2.0 upcoming update is the consistency between different use cases (see: FFF#380), I see a great opportunity to refactor that part of code and make both modders & developers lives easier.