CODEWITHSUNDEEP
smartcontractsnearprotocol
j00yn
j00yn

Reputation: 227

Contract Predecessor vs Signer vs Current

Can someone help me understand the relationship and distinction amongst these three concepts? It seems like context.predecessor == context.contractName checks are common.

Upvotes: 5

Views: 273

Answers (2)

Prathamesh Satya
Prathamesh Satya

Reputation: 1

The answer from sirwillem above explains it well

Just remember the idea behind assertions like context.predecessor == context.contractName can be:

  • Calling private methods in a contract indirectly (which can only be called by the contract itself)
  • Calling admin level methods that only the contract id (contract owner) should call

Upvotes: 0

sirwillem
sirwillem

Reputation: 722

signer - account that signed the initial transaction.

predecessor - the last account who made the current contract call.

current - the account of the contract.

For an example, consider contract contract.near and a user alice.near.

alice.near calls method foo on contract.near. In the context of foo:

  • signer == alice.near
  • predecessor == alice.near
  • current == contract.near

Then if a promise call is made to another method say faa, then its context is:

  • signer == alice.near
  • predecessor == contract.near
  • current == contract.near

So the check predecessor == current or context.predecessor == context.contractName is to make sure that the contract was the account that made the contract call. A method with this assertion is considered "private" because only the contract can call it even though it is part of a public facing API.

Upvotes: 6

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