Add new section for explanation and examples of using chainlinkVRF to Handle Different function logic request

_includes/samples/VRF/VRFv2MultiplePaths.sol

@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: MIT
+// An example of a consumer contract that relies on a subscription for funding.
+// It shows how to setup multiple execution paths for handling a response.
+pragma solidity ^0.8.7;
+
+import '@chainlink/contracts/src/v0.8/interfaces/VRFCoordinatorV2Interface.sol';
+import '@chainlink/contracts/src/v0.8/VRFConsumerBaseV2.sol';
+
+/**
+ * THIS IS AN EXAMPLE CONTRACT THAT USES HARDCODED VALUES FOR CLARITY.
+ * THIS IS AN EXAMPLE CONTRACT THAT USES UN-AUDITED CODE.
+ * DO NOT USE THIS CODE IN PRODUCTION.
+ */
+
+contract VRFv2MultiplePaths is VRFConsumerBaseV2 {
+    VRFCoordinatorV2Interface COORDINATOR;
+
+    // Your subscription ID.
+    uint64 s_subscriptionId;
+
+    // Goerli coordinator. For other networks,
+    // see https://docs.chain.link/docs/vrf/v2/supported-networks/#configurations
+    address vrfCoordinator = 0x2Ca8E0C643bDe4C2E08ab1fA0da3401AdAD7734D;
+
+    // The gas lane to use, which specifies the maximum gas price to bump to.
+    // For a list of available gas lanes on each network,
+    // see https://docs.chain.link/docs/vrf/v2/supported-networks/#configurations
+    bytes32 keyHash = 0x79d3d8832d904592c0bf9818b621522c988bb8b0c05cdc3b15aea1b6e8db0c15;
+
+    uint32 callbackGasLimit = 100_000;
+
+    // The default is 3, but you can set this higher.
+    uint16 requestConfirmations = 3;
+
+    // For this example, retrieve 1 random value in one request.
+    // Cannot exceed VRFCoordinatorV2.MAX_NUM_WORDS.
+    uint32 numWords = 1;
+
+    enum Variable {
+        A,
+        B,
+        C
+    }
+
+    uint256 public variableA;
+    uint256 public variableB;
+    uint256 public variableC;
+
+    mapping(uint256 => Variable) public requests;
+
+    // events
+    event FulfilledA(uint256 requestId, uint256 value);
+    event FulfilledB(uint256 requestId, uint256 value);
+    event FulfilledC(uint256 requestId, uint256 value);
+
+    constructor(uint64 subscriptionId) VRFConsumerBaseV2(vrfCoordinator) {
+        COORDINATOR = VRFCoordinatorV2Interface(vrfCoordinator);
+        s_subscriptionId = subscriptionId;
+    }
+
+    function updateVariable(uint256 input) public {
+        uint256 requestId = COORDINATOR.requestRandomWords(
+            keyHash,
+            s_subscriptionId,
+            requestConfirmations,
+            callbackGasLimit,
+            numWords
+        );
+
+        if (input % 2 == 0) {
+            requests[requestId] = Variable.A;
+        } else if (input % 3 == 0) {
+            requests[requestId] = Variable.B;
+        } else {
+            requests[requestId] = Variable.C;
+        }
+    }
+
+    function fulfillRandomWords(uint256 requestId, uint256[] memory randomWords) internal override {
+        Variable variable = requests[requestId];
+        if (variable == Variable.A) {
+            fulfillA(requestId, randomWords[0]);
+        } else if (variable == Variable.B) {
+            fulfillB(requestId, randomWords[0]);
+        } else if (variable == Variable.C) {
+            fulfillC(requestId, randomWords[0]);
+        }
+    }
+
+    function fulfillA(uint256 requestId, uint256 randomWord) private {
+        // execution path A
+        variableA = randomWord;
+        emit FulfilledA(requestId, randomWord);
+    }
+
+    function fulfillB(uint256 requestId, uint256 randomWord) private {
+        // execution path B
+        variableB = randomWord;
+        emit FulfilledB(requestId, randomWord);
+    }
+
+    function fulfillC(uint256 requestId, uint256 randomWord) private {
+        // execution path C
+        variableC = randomWord;
+        emit FulfilledC(requestId, randomWord);
+    }
+}

docs/vrf/v2/best-practices.md

@@ -96,3 +96,16 @@ function fulfillRandomWords(
   s_requestIndexToRandomWords[requestNumber] = randomWords;
 }
 ```
+
+## Processing VRF responses through different execution paths
+
+If you want to process VRF responses depending on predetermined conditions, you can create an `enum`. When requesting for randomness, map each `requestId` to an enum. This way, you can handle different execution paths in `fulfillRandomWords`. See the following example:
+
+```solidity
+{% include 'samples/VRF/VRFv2MultiplePaths.sol' %}
+```
+
+<div class="remix-callout">
+  <a href="https://remix.ethereum.org/#url=https://docs.chain.link/samples/VRF/VRFv2MultiplePaths.sol" target="_blank" >Open in Remix</a>
+  <a href="/docs/conceptual-overview/#what-is-remix">What is Remix?</a>
+</div>