PlacementSession | Grid Placement Docs

Draft — Unreleased:This page is in active development. APIs, class names, and behavior may change before the release is finalized. Use it as a preview of what's coming — not as a stable integration target.

Primary composition-root for the Grid Building placement system. PlacementSession is a Resource that holds all states, contexts, settings, and the entry catalog in a single object. It maps 1:1 onto the C# [code]IPlacementSession[/code] surface, enabling:

Scene-free, code-driven testing (construct a Session, pass it to systems)
Code-built placement without a scene tree injector
Single-source-of-truth composition for both the injector path (scene-composed games) and the explicit path (libraries/tools) Usage: [codeblock] # Explicit path (code-built, no injector): var session := PlacementSession.new() session.catalog = preload("res://catalog.tres") session.settings = preload("res://settings.tres") var system := PlacementSystem.create_with_session(session) # Injector path (scene-composed, existing flow): container.session = session # container delegates to session [/codeblock]

Source: addons/grid_placement/resources/placement_session.gd

Syntax

class PlacementSession extends Resource

Members

Name	Kind	Summary
`grid_placement_bundle`	Property	Configuration resource for the grid building system. When set, [method get_settings], [method get_templates], [method get_actions], [method get_debug_settings], [method get_runtime_checks], and other config-layer accessors read through this resource. This is the scene-composed on-ramp: editor-authored [code].tres[/code] files assign a [GridPlacementBundle] here.
`settings`	Property	Main settings configuration resource. When null, [method get_settings] falls back to [member grid_placement_bundle].settings.
`actions`	Property	Input action definitions used by host, input, manipulation, and drag services. When null, [method get_actions] falls back to [member grid_placement_bundle].actions.
`catalog`	Property	Catalog of available placement entries (objects + terrains).
`states`	Property	Shared states for plugin systems.
`contexts`	Property	Context for resolving references to current objects.
`terrain_selected`	Event	Emitted when [member selected_terrain_name] changes. The host connects to this signal in [method GridPlacementHost.configure] to enter terrain paint mode automatically when the UI selects a terrain.
`placeable_selected`	Event	Emitted when [member selected_placeable] changes. The host connects to this signal for parity with [signal terrain_selected] — drag service, preview builder, and host observers all react to per-session placeable changes without polling the field.
`selected_terrain_name`	Property	Runtime terrain selection for this session (NOT serialized — transient per-player state). The terrain palette UI writes the user's pick here; [GridPlacementHost] reads it from the device-resolved active session when dispatching PLACE_SINGLE_TERRAIN / terrain-brush paint. Empty means no terrain is selected and terrain dispatch is a no-op. Keeping it on the session (the one object both the UI and the host already hold) is what lets split-screen sessions each carry their own selection.
`selected_placeable`	Property	Runtime placeable selection for this session (NOT serialized — transient per-player state). The placeable UI writes the user's pick here; [GridPlacementHost] reads it from the device-resolved active session when dispatching PLACE_SINGLE_OBJECT / object-drag intents. Null means no placeable is selected and object dispatch is a no-op. Symmetric to [member selected_terrain_name] — this is the object-mode counterpart that fixes the terrain/object cross-leak where a smithy pick drove fence placement.
`logger`	Property	Centralized logger instance. Lazily initialized from config.debug when first accessed, so .tres-loaded sessions get the correct log level after [member grid_placement_bundle] is deserialized.
`from_container`	Method
`session`	Property
`get_contexts`	Method
`get_states`	Method
`get_logger`	Method
`ds`	Property
`get_mode_state`	Method
`get_targeting_state`	Method
`get_building_state`	Method
`get_manipulation_state`	Method
`get_placement_rules`	Method
`s`	Property
`get_runtime_issues`	Method
`issues`	Property
`active_states`	Property
`active_contexts`	Property
`get_settings`	Method
`get_actions`	Method
`get_templates`	Method
`get_visual_settings`	Method
`s`	Property
`get_manipulation_settings`	Method
`s`	Property
`get_debug_settings`	Method
`s`	Property
`get_runtime_checks`	Method
`get_indicator_context`	Method
`get_action_history`	Method
`building_state`	Property
`manipulation_state_ref`	Property
`s`	Property
`dump_action_history`	Method
`set_logger`	Method
`set_states`	Method
`ds`	Property

Source

addons/grid_placement/resources/placement_session.gd

Plugin docs root:gdscript/plugins/grid_placement_dev/docs