Solana: How to display the event passed by emit! on the block explorer

Show events on Solana Block Explorer

In this article, we’ll explore how to display events sent by emit!' on the Solana block explorer.

What isemit!’?

On the Solana blockchain, emit! is a function used to send events to the network. It allows you to define and execute custom functions that interact with other contracts or the blockchain itself. In this case, we’ll use it to display events on the block explorer.

Defining the event structure

First, let’s define the event structure:

#[event]

pub struct ClaimEvent {

    bar engagement: u64,

}

This defines a simple ClaimEvent structure with a single engagement field, which represents the number of engagements (or interactions) in the contract.

Using emit!'

Now let's useemit!to send aClaimEventto the block explorer:

emit!(ClaimEvent { engagement: 123 });

However, as you mentioned earlier, this will only work if we define an event structure for it. To fix this, we need to add a new event type and use the eventmacro (available in Solana's Rust SDK) to define our custom event:

use solana_sdk::event::{Event, EventRecord};


#[event]

pub struct ClaimEvent {

    bar engagement: u64,

}


impl event for ClaimEvent {

    fn signature(&self) -> &[u8] {

        // Return the event signature (not shown in this example)

        not implemented!()

    }

}

In this updated code, we define a new ClaimEventstructure and implement anEventproperty. Thesignature()method is called to return the event metadata, but for now it returns an empty byte slice.

To display events on the block explorer, you need to use theblockchainmodule:

use blockchain::{block, Event, BlockId};


fn main() {

    // Get the current block ID

    let block_id = block::BlockId::new();


    // Define an event record for our custom event

    let event_record = EventRecord::new();

    event_record.set_field("engagement", 123);


    // Create a new block object

    let block_data = block_data ! {

        id: block_id.to_string(),

        events: Some(vec![event_record.clone()]),

    };


    // Send block data to blockchain

    let mut tx = block::Transaction::new().set_data(block_data).signer().build();

    blockchain::send_transaction(&tx, "my-transaction");

}

In this example, we use the blockchainmodule to create a new block object and add our custom event record to it. We then send the block data to the blockchain using thesend_transaction()` function.

Examples of use cases

This example shows how to display events on the Solana block explorer. You can apply similar logic to other contracts or integrations, such as:

• View user engagement metrics

• View transaction history

• Log API calls

Please note that this is a simplified example and you should consider factors such as event persistence, logging, and security when implementing custom events on the Solana blockchain.

Ethereum Websocket Graph Within Class