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gregWiki/docs/guides/mod-developers/greg-hooks-showcase.md
Marvin ee3f30e502 docs: update sidebar and documentation to include greg hooks registry
- Added new items to the sidebar for 'greg-hooks-and-events' and 'greg-hooks-registry' under the Framework and Reference categories, respectively.
- Enhanced the documentation layout by including references to the greg hooks registry in various guides and topics, improving accessibility to hook-related information.
- Updated descriptions in the documentation to clarify the purpose and usage of the greg hooks and their registry.

This commit aims to improve the visibility and usability of the greg hooks registry within the documentation.
2026-04-10 03:36:30 +02:00

78 lines
3.2 KiB
Markdown

---
title: Greg hooks showcase (sample mod)
sidebar_label: Greg hooks showcase
description: Subscribe to greg.* hooks via GregShowcaseMod, GregEventDispatcher, GregPayload, and optional OnCancelable veto.
---
# Greg hooks showcase
The **gregFramework** repo ships **GregShowcaseMod** at `mods/GregShowcaseMod/`. It demonstrates the public API only:
- `GregEventDispatcher.On` / `Once` / `OnCancelable` / `UnregisterAll`
- `GregHookName.Create(GregDomain.*, "Action")`
- `GregPayload.Get<T>` / `GregPayload.Dump` for anonymous payloads
## Canonical hook strings
Runtime names look like `greg.<DOMAIN>.<Action>`. Always build them with `GregHookName.Create` — do not concatenate raw strings in mods.
## Registry
**`greg_hooks.json`** at the **gregFramework** repository root is the canonical catalog (`description`, `payloadSchema`, `strategy`, optional `legacy`). A copy is emitted next to **`FrikaModdingFramework.dll`** for `GregCompatBridge` legacy resolution.
Authoritative documentation: [greg hooks registry (IL2CPP)](/wiki/reference/greg-hooks-registry) — regeneration script, whitelist, and Harmony deduplication rules.
## FFI bridge and greg.* emission
`DataCenterModLoader.EventDispatcher` emits **`greg.*`** events through **`GregHookIntegration`** for the same gameplay moments as the Rust FFI event ids (money, cables, customers, save/load, etc.), even when the FFI bridge is not connected.
## Payload access patterns
**Pattern A — dynamic (anonymous types from compiler):**
```csharp
private static void OnMoneyChanged(object payload)
{
dynamic p = payload;
float delta = (float)p.coinChangeAmount;
float balance = (float)p.newBalance;
MelonLogger.Msg($"Δ={delta} → {balance}");
}
```
**Pattern B — `GregPayload` (reflection, case-insensitive property names):**
```csharp
private static void OnReputationChanged(object payload)
{
var amount = GregPayload.Get<float>(payload, "amount");
var rep = GregPayload.Get<float>(payload, "reputation");
MelonLogger.Msg($"Reputation: {amount} → {rep}");
}
```
**Pattern C — typed record (when you define a shared contract in your mod or core):**
```csharp
// public record PlayerMoneyPayload(float CoinChangeAmount, float NewBalance, bool WithoutSound, bool Accepted);
// if (payload is PlayerMoneyPayload p) { ... }
```
Use **`GregPayload.Dump(payload)`** for one-line debug strings.
## Prefix hooks and cancellation
Hooks that run **before** the original method (Harmony Prefix) can call **`GregEventDispatcher.InvokeCancelable(hookName, payload)`**. Mods register **`GregEventDispatcher.OnCancelable(hookName, p => bool, modId)`**; if any handler returns `false`, the integration can skip the original (e.g. `Player.UpdateCoin`).
Showcase: enable `blockNegativeTransactions` in `content/modconfig.json` to register a veto on large negative `coinChangeAmount` values.
## Configuration
Edit **`content/modconfig.json`** next to the built DLL (defaults are copied from the repo). Keys include `logPlayerEvents`, `logNetworkEvents`, `blockNegativeTransactions`, `reputationWarningThreshold`.
## See also
- [Mod developers (hub)](./overview)
- [System architecture principles](/wiki/meta/system-architecture-principles)
- [Framework](/wiki/mods/framework)