invokefunction Method
Invokes a smart contract with its scripthash based on the specified operation and parameters and returns the result.
note
This method is used to test your VM script as if they ran on the blockchain at that point in time. This RPC call does not affect the blockchain in any way.
You must install the plugin RpcServer before you can invoke the method.
Parameter Description#
scripthash: Smart contract scripthash. You need to use the proper byte order of the address passed according to its data type. If the data type is Hash160, use the big endian scripthash; if the data type is ByteArray, use the little endian scripthash.
operation: The operation name (string).
params: Optional. The parameters to be passed into the smart contract operation.
signers or witnesses: Optional. You can set a list of signature accounts or witnesses for the transaction.
The structure of signers is as follows:
account: signature account
scopes: signature's valid scopes, allowed values are:
- None: Only transactions are signed and no contracts are allowed to use this signature.
- CalledByEntry: It only applies to the chain call entry. That is, if the user invokes contract A, and then contract A calls contract B, only contract A can use the signature. It is recommended as the default value for the wallet.
- CustomContracts: Custom contract. The signature can be used in the specified contract. It can be used in conjunction with CalledByEntry.
- CustomGroups: Custom contract groups that can be used in a specified contract group. It can be used in conjunction with CalledByEntry.
- Global: Global. The risk is extremely high because the contract may transfer all assets in the address. Only choose it when the contract is extremely trusted.
allowedcontracts: contracts of the signature can take effect, if scopes is CustomContracts
allowedgroups: pubkeys of the signature can take effect, if scopes is CustomGroups
The structure of witnesses is as follows:
- invocation: InvocationScript in Base64 encoded format.
- verification: VerificationScript in Base64 encoded format.
note
You need to use the proper byte order of the address passed according to its data type. If the data type is Hash160, use the big endian script hash; if the data type is ByteArray, use the little endian scripthash.
For example:
{ "type": "String", "value": "Hello"} { "type": "Hash160", "value": "0xf621168b1fce3a89c33a5f6bcf7e774b4657031c"} { "type": "ByteArray", "value": "7472616e73666572"}Example#
Request body:
{ "jsonrpc": "2.0", "id": 1, "method": "invokefunction", "params": [ "0xf61eebf573ea36593fd43aa150c055ad7906ab83", "transfer", [ { "type": "Hash160", "value": "0x86df72a6b4ab5335d506294f9ce993722253b6e2" }, { "type": "Hash160", "value": "0xebae4ab3f21765e5f604dfdd590fdf142cfb89fa" }, { "type": "Integer", "value": "10000" }, { "type": "String", "value": "" } ], [ { "account": "0x86df72a6b4ab5335d506294f9ce993722253b6e2", "scopes": "CalledByEntry", "allowedcontracts": [], "allowedgroups": [] } ] ]}Response body:
{ "jsonrpc": "2.0", "id": 1, "result": { "script": "DAABECcMFPqJ+ywU3w9Z3d8E9uVlF/KzSq7rDBTitlMicpPpnE8pBtU1U6u0pnLfhhTAHwwIdHJhbnNmZXIMFIOrBnmtVcBQoTrUP1k26nP16x72QWJ9W1I=", "state": "HALT", "gasconsumed": "999972", "exception": null, "stack": [ { "type": "Boolean", "value": true } ], "tx": "AI3PBQRolZgAAAAAAMrSEgAAAAAAtRcAAAHitlMicpPpnE8pBtU1U6u0pnLfhgEAWQwAARAnDBT6ifssFN8PWd3fBPblZRfys0qu6wwU4rZTInKT6ZxPKQbVNVOrtKZy34YUwB8MCHRyYW5zZmVyDBSDqwZ5rVXAUKE61D9ZNupz9ese9kFifVtSAUIMQB87UjubTE7Kb/fOe8Yu2QDUQJ6c5pL9LjcoFaNkEiJzLY5yd72jrsvVbVFNZ6ObWloAmLkjCgDXw9enkVtwVBMrEQwhAs7UMjl93ETtugMcC8O5M/KP3ZZ3eS17IObANt2qrPHiEQtBE43vrw==" }}Response description:
script: the invocation script of the contract. You can analysis from https://neo.org/converter
SYSCALL System.Contract.CallPUSHDATA1 0xf61eebf573ea36593fd43aa150c055ad7906ab83PUSHDATA1 transferPUSHDATA1 0x86df72a6b4ab5335d506294f9ce993722253b6e2PUSHDATA1 0xebae4ab3f21765e5f604dfdd590fdf142cfb89faPUSHINT16 10000PUSHDATA1state:
HALTmeans the vm executed successfully, andFAULTmeans the vm exited due to an exception.gasconsumed: the system fee consumed for invocation.
stack: the contract execution result. If the value is String or ByteArray, it is encoded by Base64.
tx: the transaction's hex string of this invocation, need open wallet and added signers correctly.
About iterator#
If the execution result of contract includes iterators, the iteration times are constrained according to the MaxIteratorResultItems value configured in the RpcServer config file. The default limit is 100 times.
In the following example, up to 6 returned results are actually available. When the MaxIteratorResultItems value is 5, only 5 iterations are returned and truncated is true, indicating that there is still data to be returned.
{ "jsonrpc": "2.0", "id": 3, "result": { "script": "wh8MBnRva2VucwwUR7xWZRSFd3BpKcM7Mj3g3v4/u3ZBYn1bUg==", "state": "HALT", "gasconsumed": "2288880", "exception": null, "stack": [ { "type": "InteropInterface", "iterator": [ { "type": "ByteString", "value": "Ymp5eDMuY3A=" }, { "type": "ByteString", "value": "Ymp5eDUuY3A=" }, { "type": "ByteString", "value": "Ymp5eDEuY3A=" }, { "type": "ByteString", "value": "Ymp5eDIuY3A=" }, { "type": "ByteString", "value": "Ymp5eDQuY3A=" } ], "truncated": true } ] }}When the MaxIteratorResultItems value is greater than or equal to 6, then 6 iterations are returned and truncated is false, indicating that all data has been returned.
{ "jsonrpc": "2.0", "id": 3, "result": { "script": "wh8MBnRva2VucwwUR7xWZRSFd3BpKcM7Mj3g3v4/u3ZBYn1bUg==", "state": "HALT", "gasconsumed": "2288880", "exception": null, "stack": [ { "type": "InteropInterface", "iterator": [ { "type": "ByteString", "value": "Ymp5eDMuY3A=" }, { "type": "ByteString", "value": "Ymp5eDUuY3A=" }, { "type": "ByteString", "value": "Ymp5eDEuY3A=" }, { "type": "ByteString", "value": "Ymp5eDIuY3A=" }, { "type": "ByteString", "value": "Ymp5eDQuY3A=" }, { "type": "ByteString", "value": "Ymp5eDYuY3A=" } ], "truncated": false } ] }}