The Ocelloids Contracts Module provides support for Substrate's contracts pallet, specifically for decoding contract messages, events, and constructors, and enables easy filtering of these elements. It is designed to be used in conjunction with the Ocelloids Core Module.
The packages/pallets/contracts
module source folder is structured as follows:
Directory | Description |
---|---|
converters | Contract data type conversions |
operators | Reactive operators for contract activities |
types | Extended contract types |
Refer to the SDK documentation.
Here is a simple example of how to track all events emitted by the link contract deployed on Rococo Contracts:
import { readFileSync } from 'node:fs';
import path from 'node:path';
import { WsProvider } from '@polkadot/api';
import { Abi } from '@polkadot/api-contract';
import {
SubstrateApis,
blocks
} from '@sodazone/ocelloids-sdk';
import {
filterContractEvents,
converters
} from '@sodazone/ocelloids-sdk-contracts';
const CONTRACT_ADDRESS = '5GdHQQkRHvEEE4sDkcLkxCCumSkw2SFBJSLKzbMTNARLTXz3';
const contractMetadataJson = readFileSync((path.resolve(__dirname, './metadata.json'))).toString();
const abi = new Abi(contractMetadataJson);
const apis = new SubstrateApis({
rococoContracts: {
provider: new WsProvider('wss://rococo-contracts-rpc.polkadot.io')
}
});
apis.rx.rococoContracts.pipe(
blocks(),
filterContractEvents(abi, CONTRACT_ADDRESS)
).subscribe(
x => console.log({
...converters.contracts.toNamedPrimitive(x),
blockEvent: x.blockEvent.toHuman()
})
);
Output:
{
blockEvent: {
eventId: '2920834-2-1',
extrinsicId: '2920834-2',
extrinsicPosition: 1,
blockNumber: '2,920,834',
method: 'ContractEmitted',
section: 'contracts',
index: '0x2803',
data: {
contract: '5GdHQQkRHvEEE4sDkcLkxCCumSkw2SFBJSLKzbMTNARLTXz3',
data: '0x00144a736d48325868747470733a2f2f6d79666162756c6f75732e75726c'
}
},
event: {
docs: [ ' A new slug mapping was created.' ],
identifier: 'Shortened',
index: 0
},
args: { slug: 'JsmH2', url: 'https://myfabulous.url' }
}
For more detailed examples, please refer to the watch-contracts example application.