Basic demo app using Moralis. Shows gas usage stats for the top 10 users with the highest average gas fees.
https://moralis-gas-demo.netlify.app/
The quickest way to get up and running is by linking the CDN in the <head> tag of the html file.
<head>
<script src="https://cdn.jsdelivr.net/npm/web3@latest/dist/web3.min.js"></script>
<script src="https://unpkg.com/moralis/dist/moralis.js"></script>
</head>Next initialize Moralis by copying the API key and URL from your Moralis Server instance
<script>
Moralis.initialize("your app ID");
Moralis.serverURL = "your server URL";
// i.e. https://dk...mfu.moralis.io:2053/server";
</script>// promises
Moralis.Web3.authenticate().then(function (user) {
console.log(user.get("ethAddress"));
});
// async/await
const user = await Moralis.Web3.authenticate();This will prompt the user to connect their wallet and sign a message. In this case the wallet address is like the "user name" and the signature the "password".
Moralis.User.logOut();The user is returned from the Moralis.Web3.authenticate() function but, the current logged in user can also be found using the following.
const user = Moralis.User.current();The current user will always be authenticated and will return null if there is no logged in user.
Once a user has been authenticated, the server can sync their transactions and that data can be queried. This requires some set up in the Moralis backend.
Moralis extends the functionality of Parse and should be able to do anything Prase can. See the docs here for more details.
Any of the collections listed under the "Browse" section in the Moralis Dashboard can be queried.
const user = Moralis.User.current();
const userAddress = user.get("ethAddress");
// create a query on the EthTransactions collection
const collection = "EthTransactions";
const query = new Moralis.Query(collection);
// get all the transactions sent by the current user
query.equalTo("from_address", userAddress);
// run the query
const results = await query.find();More advanced queries, like ones which use "group by" require a Could Function as they need special permissions. This is a query which runs on the server and saves the client from doing more intense work that can be more easily processed server side.
Cloud Functions are defined as follows. Any params will be be in request.params.
Moralis.Cloud.define("myCloudFunction", async function (request) {
// function code here
const foo = request.params.foo;
});The function definitions need to be added to the Moralis Server. Click the "Cloud Functions" button. Custom user defined Cloud Functions go into the customUserPlugin() function. Click "Save File" when finished.
// @@@ Paste this code into the Moralis Cloud Functions section on the server @@@
Moralis.Cloud.define("topTenAvgGas", async function (request) {
const query = new Moralis.Query("EthTransactions");
const pipeline = [
{
// group by "from_address"
// add computed properties with the avg, min, max, count
group: {
objectId: "$from_address",
avgGas: { $avg: "$gas_price" },
minGas: { $min: "$gas_price" },
maxGas: { $max: "$gas_price" },
count: { $sum: 1 },
},
},
{ sort: { avgGas: -1 } }, // descending
{ limit: 10 },
];
// the master key is required for aggregate queries
const results = await query.aggregate(pipeline, { useMasterKey: true });
return results;
});See the Query Aggregate and MongoDB docs for more details on queries.
Now that the Cloud Function is defined on the Moralis server it's time to put it to use!
const couldFunctionName = "topTenAvgGas";
const args = {};
const results = await Moralis.Cloud.run(couldFunctionName, args);