5 anchors ipfs data on a smart contract

.openzeppelin/goerli.json

@@ -288,6 +288,43 @@
         ],
         "storageDiff": []
       }
+    },
+    "DocExchange": {
+      "address": "0x1E6C6D4c33FfB5763562DDA25F260e84Be69d2C7",
+      "constructorCode": "608060405234801561001057600080fd5b50610458806100206000396000f3fe",
+      "bodyBytecodeHash": "167057e1f0e73f4632f0d9c828320dc88f39b7468ad91b99836fc4ebe297285e",
+      "localBytecodeHash": "e027048d52e4df22ba208f5e508a8bbb2ad41d5496ee54ac8a4266f74c781cdb",
+      "deployedBytecodeHash": "e027048d52e4df22ba208f5e508a8bbb2ad41d5496ee54ac8a4266f74c781cdb",
+      "types": {
+        "t_bytes": {
+          "id": "t_bytes",
+          "kind": "elementary",
+          "label": "bytes"
+        },
+        "t_mapping<t_bytes>": {
+          "id": "t_mapping<t_bytes>",
+          "valueType": "t_bytes",
+          "label": "mapping(key => bytes)",
+          "kind": "mapping"
+        }
+      },
+      "storage": [
+        {
+          "contract": "DocExchange",
+          "path": "contracts/DocExchange.sol",
+          "label": "documents",
+          "astId": 2138,
+          "type": "t_mapping<t_bytes>",
+          "src": "105:35:13"
+        }
+      ],
+      "warnings": {
+        "hasConstructor": false,
+        "hasSelfDestruct": false,
+        "hasDelegateCall": false,
+        "hasInitialValuesInDeclarations": false,
+        "uninitializedBaseContracts": []
+      }
     }
   },
   "solidityLibs": {},
@@ -307,6 +344,15 @@
         "admin": "0x5c19BF66CC2c9386Cdf06d346F32F140A4559be9",
         "kind": "Upgradeable"
       }
+    ],
+    "ledger-academy/DocExchange": [
+      {
+        "address": "0xcB4c372940117184A3fe3eBDe36d118b6f3A454e",
+        "version": "1.0.0",
+        "implementation": "0x1E6C6D4c33FfB5763562DDA25F260e84Be69d2C7",
+        "admin": "0x5c19BF66CC2c9386Cdf06d346F32F140A4559be9",
+        "kind": "Upgradeable"
+      }
     ]
   },
   "manifestVersion": "2.2",

.openzeppelin/project.json

@@ -1,7 +1,8 @@
 {
   "manifestVersion": "2.2",
   "contracts": {
-    "ADIToken": "ADIToken"
+    "ADIToken": "ADIToken",
+    "DocExchange": "DocExchange"
   },
   "dependencies": {
     "@openzeppelin/contracts-ethereum-package": "^3.0.0"

contracts/DocExchange.sol

@@ -0,0 +1,17 @@
+pragma solidity ^0.6.0;
+
+
+contract DocExchange {
+    event DocumentAdded(address owner, bytes cid);
+
+    mapping(address => bytes) documents;
+
+    function addDocument(bytes memory cid) public {
+        documents[msg.sender] = cid;
+        emit DocumentAdded(msg.sender, cid);
+    }
+
+    function getMyDocument() public view returns (bytes memory cid) {
+        return documents[msg.sender];
+    }
+}

src/IpfsPage.tsx

@@ -1,12 +1,60 @@
 import React, { useState, useEffect } from "react";
+import { useWeb3React } from "@web3-react/core";
+import Web3 from "web3";
+import DocExchange from "./contracts/DocExchange.json";
 
-import IPFS from "ipfs";
+import IPFS, { Buffer, CID } from "ipfs";
 import _secrets from "../.secrets.json";
 
 const IpfsPage: React.FC = () => {
+  const { account, library: web3 } = useWeb3React<Web3>();
   const [ipfsNode, setIpfsNode] = useState();
 
   const [files, setFiles] = useState([]);
+  const [myDocumentContent, setMyDocumentContent] = useState();
+
+  const contract = new web3.eth.Contract(
+    DocExchange.abi,
+    _secrets.docExchangeAddress
+  );
+
+  async function anchorOnChain(cid) {
+    const bytes = [...cid.buffer];
+
+    const promiEvent = contract.methods.addDocument(bytes).send({
+      from: account,
+      gasPrice: 21 * 1e5,
+      gas: 30 * 1e5,
+    });
+
+    promiEvent.on("transactionHash", console.log);
+    promiEvent.on("receipt", console.log);
+    promiEvent.on("confirmation", (number, confirmation) => {
+      console.debug(confirmation);
+    });
+  }
+
+  async function getMyDocumentFromChainAndResolve() {
+    const resultBytes = await contract.methods.getMyDocument().call({
+      from: account,
+    });
+    console.log("cid stored on chain", resultBytes);
+
+    const bytes = Web3.utils.hexToBytes(resultBytes);
+    const cid = new CID(Buffer.from(bytes));
+    console.log("CID recovered from contract", cid.toString());
+
+    const contentChunks = await ipfsNode!.cat(cid);
+    const awaitedChunks: any[] = [];
+    // eslint-disable-next-line no-restricted-syntax
+    for await (const chunk of contentChunks) {
+      awaitedChunks.push(chunk);
+    }
+    const result = Buffer.concat(awaitedChunks).toString();
+    console.log("content: ", result);
+    setMyDocumentContent(result);
+    return result;
+  }
 
   async function addToIpfs(content: string | any[]): Promise<any[]> {
     const addResult = ipfsNode!.add(content);
@@ -25,6 +73,8 @@ const IpfsPage: React.FC = () => {
     const ipfsResult = await addToIpfs(_currentContent);
     console.log(ipfsResult);
 
+    anchorOnChain(ipfsResult[0].cid);
+
     setFiles([...files, ipfsResult[0]]);
   };
 
@@ -39,12 +89,18 @@ const IpfsPage: React.FC = () => {
   return (
     <div>
       <form onSubmit={submit}>
-        <textarea name="thecontent">test</textarea>
+        <textarea
+          name="thecontent"
+          rows={10}
+          cols={40}
+          defaultValue="type anything you'd like to store forever..."
+        ></textarea>{" "}
+        <br />
         <button type="submit" value="store!">
-          store!
+          store forever!
         </button>
       </form>
-      <h2>Files:</h2>
+      <h2>History:</h2>
       <ul>
         {files.map((f) => (
           <li>
@@ -57,6 +113,11 @@ const IpfsPage: React.FC = () => {
           </li>
         ))}
       </ul>
+      <h2>My Document:</h2>
+      <button onClick={getMyDocumentFromChainAndResolve}>
+        get my document.
+      </button>
+      <p>{myDocumentContent}</p>
     </div>
   );
 };

src/contracts/DocExchange.json

@@ -0,0 +1 @@
+../../build/contracts/DocExchange.json