Preimage¶
Calls¶
note_preimage¶
Register a preimage on-chain.
If the preimage was previously requested, no fees or deposits are taken for providing the preimage. Otherwise, a deposit is taken proportional to the size of the preimage.
Attributes¶
| Name | Type |
|---|---|
| bytes | Vec<u8> |
Python¶
call = substrate.compose_call(
'Preimage', 'note_preimage', {'bytes': 'Bytes'}
)
request_preimage¶
Request a preimage be uploaded to the chain without paying any fees or deposits.
If the preimage requests has already been provided on-chain, we unreserve any deposit a user may have paid, and take the control of the preimage out of their hands.
Attributes¶
| Name | Type |
|---|---|
| hash | T::Hash |
Python¶
call = substrate.compose_call(
'Preimage', 'request_preimage', {'hash': '[u8; 32]'}
)
unnote_preimage¶
Clear an unrequested preimage from the runtime storage.
Attributes¶
| Name | Type |
|---|---|
| hash | T::Hash |
Python¶
call = substrate.compose_call(
'Preimage', 'unnote_preimage', {'hash': '[u8; 32]'}
)
unrequest_preimage¶
Clear a previously made request for a preimage.
NOTE: THIS MUST NOT BE CALLED ON hash MORE TIMES THAN request_preimage.
Attributes¶
| Name | Type |
|---|---|
| hash | T::Hash |
Python¶
call = substrate.compose_call(
'Preimage', 'unrequest_preimage', {'hash': '[u8; 32]'}
)
Events¶
Cleared¶
A preimage has ben cleared.
Attributes¶
| Name | Type | Composition |
|---|---|---|
| hash | T::Hash |
[u8; 32] |
Noted¶
A preimage has been noted.
Attributes¶
| Name | Type | Composition |
|---|---|---|
| hash | T::Hash |
[u8; 32] |
Requested¶
A preimage has been requested.
Attributes¶
| Name | Type | Composition |
|---|---|---|
| hash | T::Hash |
[u8; 32] |
Storage functions¶
PreimageFor¶
The preimages stored by this pallet.
Python¶
result = substrate.query(
'Preimage', 'PreimageFor', ['[u8; 32]']
)
Return value¶
'Bytes'
StatusFor¶
The request status of a given hash.
Python¶
result = substrate.query(
'Preimage', 'StatusFor', ['[u8; 32]']
)
Return value¶
{'Requested': 'u32', 'Unrequested': (None, ('AccountId', 'u128'))}
Errors¶
AlreadyNoted¶
Preimage has already been noted on-chain.
NotAuthorized¶
The user is not authorized to perform this action.
NotNoted¶
The preimage cannot be removed since it has not yet been noted.
NotRequested¶
The preimage request cannot be removed since no outstanding requests exist.
Requested¶
A preimage may not be removed when there are outstanding requests.
TooLarge¶
Preimage is too large to store on-chain.