feat(example): Custom web proxies usage and documentation (#2729)

* feat: Added example for custom web proxies usage and documentation

Signed-off-by: ivaylogarnev-limechain <[email protected]>

* fix: Comments and CommonJS test

Signed-off-by: ivaylogarnev-limechain <[email protected]>

* fix: Typo in README

Signed-off-by: ivaylogarnev-limechain <[email protected]>

* refactor: Introduced .env for credentials

Signed-off-by: ivaylogarnev-limechain <[email protected]>

* refactor: Removed unecessary comment within README

Signed-off-by: ivaylogarnev-limechain <[email protected]>

---------

Signed-off-by: ivaylogarnev-limechain <[email protected]>

common_js_test/src/test.js

@@ -18,7 +18,11 @@ describe("CommonJS", function () {
                 console.log(`Failed for ${nodeAccountId}`);
             }
         }
+
+        // Close the client connection
         client.close();
+
+        // Ensure that at least one attempt was successful
         if (!succeededAtLeastOnce) {
             throw new Error("No successful query attempts were made.");
         }

examples/custom-grpc-web-proxies-network/.env.sample

@@ -0,0 +1,6 @@
+# Hedera Operator Account ID
+REACT_APP_OPERATOR_ID="YOUR_OPERATOR_ID"
+
+# Hedera Operator Private Key
+REACT_APP_OPERATOR_KEY="YOUR_PRIVATE_KEY"
+

examples/custom-grpc-web-proxies-network/.gitignore

@@ -0,0 +1,13 @@
+# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
+
+# dependencies
+/node_modules
+
+# production
+/build
+
+.env
+
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*

examples/custom-grpc-web-proxies-network/README.md

@@ -0,0 +1,62 @@
+# Custom Network Configuration with gRPC Web Proxies
+
+This guide demonstrates how to configure the Hedera SDK to communicate with a custom network using gRPC web proxies in a React application. The example sets up a transfer transaction, which is triggered when the page is loaded, using a custom network configuration with multiple gRPC web proxies.
+
+## Steps to configure the custom network
+
+### Prerequisites
+
+-   Install the required Node modules by running `npm install`
+-   Create a `.env` file in the root directory and add your credentials.
+
+### 1. Setup the operator account
+
+First, you need to set up your operator account and private key. These credentials are required to sign and authorize the transaction.
+
+```javascript
+const operatorId = AccountId.fromString("<YOUR_ACCOUNT_ID>");
+const operatorKey = PrivateKey.fromStringECDSA("<YOUR_PRIVATE_KEY>");
+```
+
+### 2. Create a custom network with gRPC web proxies
+
+Define a list of gRPC web proxies to communicate with your custom network. Each entry consists of a proxy URL and its associated account ID.
+
+```javascript
+const nodes = {
+    "https://testnet-node02-00-grpc.hedera.com:443": new AccountId(5),
+    "https://testnet-node03-00-grpc.hedera.com:443": new AccountId(6),
+    "https://testnet-node04-00-grpc.hedera.com:443": new AccountId(7),
+};
+```
+
+These proxy URLs correspond to the gRPC web proxies you wish to use for the custom network.
+
+### 3. Setup the `Client` using `Client.forNetwork()`
+
+To configure the client with the custom network, use `Client.forNetwork()` and pass the list of nodes you defined. The SDK automatically detects the environment (whether it's a browser or Node.js environment).
+
+```javascript
+const client = Client.forNetwork(nodes);
+client.setOperator(operatorId, operatorKey);
+```
+
+In the browser environment, this will use gRPC web proxies.
+
+### 4. Configure the transaction for the Custom Network
+
+Before sending a transaction, you need to configure it with the necessary parameters, such as the sender, receiver, and amount. Here's how to create a transfer transaction using the configured client for the custom network.
+
+```javascript
+const transferTransaction = new TransferTransaction()
+    .addSender(senderAccountId, amountToSend)
+    .addReceiver(receiverAccountId, amountToReceive)
+    .setTransactionMemo("Transfer via custom gRPC web proxy network")
+    .setTransactionFee(transactionFee);
+
+const response = await transferTransaction.execute(client);
+```
+
+### 5. Running the application
+
+Once you've set up the client and transaction as described above, you can run your React application with `npm start`. The transfer transaction will be executed using the **custom gRPC web proxies** configured in the Client.forNetwork() method.