From 0ac9380a900e00f5b75261e1eda1bbecefb66690 Mon Sep 17 00:00:00 2001
From: CSDUMMI <31551856+CSDUMMI@users.noreply.github.com>
Date: Sat, 2 Oct 2021 23:38:22 +0200
Subject: [PATCH] Example for how the validationFn could work.

I wanted to give people an example in code of my idea for validation functions as an additional and more powerful
custom validation & access control mechanism than Access Controllers are currently.
---
 src/KeyValueIndex.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/KeyValueIndex.js b/src/KeyValueIndex.js
index a7520bd..25f68b8 100644
--- a/src/KeyValueIndex.js
+++ b/src/KeyValueIndex.js
@@ -1,8 +1,10 @@
 'use strict'
 
 class KeyValueIndex {
-  constructor() {
+  constructor(validationFn, store) {
     this._index = {}
+    this._validationFn = validationFn
+    this._store = store
   }
 
   get(key) {
@@ -14,7 +16,7 @@ class KeyValueIndex {
       .slice()
       .reverse()
       .reduce((handled, item) => {
-        if(!handled.includes(item.payload.key)) {
+        if(!handled.includes(item.payload.key) && this._validationFn(item, store)) {
           handled.push(item.payload.key)
           if(item.payload.op === 'PUT') {
             this._index[item.payload.key] = item.payload.value