Events on the Solana Block Explorer
In this article we will examine how events are displayed by “Emit!” Are handed over to the Solana Block Explorer.
What is emit!?
On the Solana blockchain, emit! Is a function with which events are sent to the network. You can define and carry out custom functions that interact with other contracts or the blockchain yourself. In this case we will use it to display an event in the Block Explorer.
Defining the event structure
Let us first define the event structure:
`Rost
#[Event]
PUB Struct system event {
Pub engagement: U64,
}
`
This defines a simple “claim” structure with a single field “commitment”, which represents the number of engagements (or interactions) in the contract.
Use emit!
Now let us “emit!” Use to send the “damage event” to the Block Explorer:
`Rost
Emit! (Advoice Event {Engagement: 123});
`
As you have already mentioned, however, this only works if we define an event structure for it. To fix this, we have to add a new type of event and use the “Event” macro (available in Solanas Rust SDK) to define our user -defined event:
`Rost
Use Solana_SDK :: Event :: {event, eventrecord};
#[Event]
PUB Struct system event {
Pub engagement: U64,
}
IMPLE ANDISTION FOR DISCACTION EVENT {
fn signature (& self) -> & [u8] {
// return the event signature (not displayed in this example)
Unimplemented! ()
}
}
`
In this updated code we define a new “damage event structure” and implement the event feature. The Signature () Method is called to return the metadata of the event, but at the moment there is an empty byte disc.
Events on Block Explorer
To display events in the Block Explorer, you must use the “Blockchain” module:
`Rost
Use blockchain :: {block, event, blockid};
fn main () {
// you get the current block -id
be block_id = block :: blockid :: new ();
// Define an event record for our custom event
leave event_record = eventrecord :: new ();
event_record.set_field (“Engagement”, 123);
// Erstellen Sie ein neues Blockobjekt
Lassen Sie block_data = block_data! {
ID: block_id.to_string (),
Events: some (VEC! [Event_record.clone ()]),
};
// Send the block data to the blockchain
Leave courage tx = block :: transaction :: new (). Set_data (block_data) .Signer (). Build ();
Blockchain :: Send_transaction (& tx, “My-transaction”);
}
`
In this example, we use the “Blockchain” module to create a new block object and add our user -defined event data set. Then we send the block data to the blockchain with the function `Send_transaction () ‘.
Example application cases
This example shows how to display events in the Solana Block Explorer. You can use a similar logic for other contracts or integrations, such as: B.:
- Show metrics for user engagements
- Show transaction history
- Register API calls
Note that this is a simplified example and that you should consider factors such as event duration, logging and safety when implementing custom events on the Solana blockchain.