SpendCostRuleBase | 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.

Abstract base class for placement rules that spend id-keyed costs. Subclasses supply a provider (duck-typed [Object]) and a [Dictionary] of [StringName] id -> [int] cost. The rule is agnostic about what the ids represent (currency, items, magic dust) — the game expresses its vocabulary by injecting the appropriate provider. [b]Required provider contract[/b] (enforced at runtime via [method get_setup_issues]):[br] [code]get_count_by_id(id: StringName) -> int[/code][br] [code]try_remove_by_id(id: StringName, amount: int) -> int[/code][br] [code]try_add_by_id(id: StringName, amount: int) -> int[/code] (rollback path)[br][br] [b]Atomicity[/b]: if any id cannot be spent in full, every amount already removed is refunded via [code]try_add_by_id[/code] before the failure is reported. Subclasses should not override [method apply] without preserving this contract.[br][br] This class is [code]@abstract[/code] — instantiate [SpendByIdRule] or [SpendMaterialsRuleById] instead.

Source: addons/grid_placement/placement/placement_rules/template_rules/spend_cost_rule_base.gd

Syntax

class SpendCostRuleBase extends PlacementRule

Members

Name	Kind	Summary
`costs`	Property	Item id -> amount that must be spent for placement to succeed.
`validate_placement`	Method
`missing`	Property
`failed_message`	Property
`apply`	Method
`issues`	Property
`spent`	Property
`removed`	Property
`tear_down`	Method
`get_setup_issues`	Method
`issues`	Property
`get_missing_costs`	Method
`missing`	Property
`have`	Property

Source

addons/grid_placement/placement/placement_rules/template_rules/spend_cost_rule_base.gd

Plugin docs root:gdscript/plugins/grid_placement_dev/docs