Interacting with Near
The components can use the Near
object to interact with smart contracts in the NEAR blockchain. There are three methods:
Near.view​
Queries a read-only method from a NEAR smart contract, returning:
null
: If the query is still being processedundefined
: If the query is complete and no value was returned by the contract- A value: If the query is complete and a value was returned by the contract
Parameters
param | required | type | description |
---|---|---|---|
contractName | required | string | Name of the smart contract |
methodName | required | string | Name of the method to call |
args | optional | object instance | Arguments to pass to the method |
blockId/finality | optional | string | Block ID or finality of the transaction |
subscribe | optional | boolean | This feature allows users to subscribe to a query, which automatically refreshes the data for all subscribers every 5 seconds. |
Notice that the optional parameter subscribe
allows users to subscribe to a query, which automatically refreshes the data every 5 seconds.
Avoiding a Common Pitfall​
If you want to initialize the state with the result of a Near.view
call, be sure to check first that the value was obtained, to avoid initializing the state with null
.
If you don't want to delay the render of your component, you can also use the useEffect
hook to control the value returned by Near.view
Near.call​
Calls a smart contract method from the blockchain. Since a transaction needs to be signed, the user must be logged in in order to make the call.
Parameters
param | required | type | description |
---|---|---|---|
contractName | required | string | Name of the smart contract to call |
methodName | required | string | Name of the method to call on the smart contract |
args | optional | object instance | Arguments to pass to the smart contract method as an object instance |
gas | optional | string / number | Maximum amount of gas to be used for the transaction (default 300Tg) |
deposit | optional | string / number | Amount of NEAR tokens to attach to the call as deposit (in yoctoNEAR units) |
Remember that you can login using the Login
button at the navigation bar.
Near.block​
Queries a block from the blockchain.
Parameters
param | required | type | description |
---|---|---|---|
blockHeightOrFinality | optional | any | The block height or finality level to use for the blockchain query (desired block height, or one of the following strings: optimistic , final ) |
- desired block height: The height of the specific block to query, expressed as a positive integer
optimistic
: Uses the latest block recorded on the node that responded to your query (< 1 second delay)final
: a block that has been validated on at least 66% of the nodes in the network (approx. 2s)