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# Hooks

This section contains a description of the module's `hooks`. Hooks are operations that are executed automatically when events are raised.

## Staking hooks

The slashing module implements the `StakingHooks` defined in `x/staking` and are used as record-keeping of validators information. During the app initialization, these hooks should be registered in the staking module struct.

The following hooks impact the slashing state:

* `AfterValidatorBonded` creates a `ValidatorSigningInfo` instance as described in the following section.
* `AfterValidatorCreated` stores a validator's consensus key.
* `AfterValidatorRemoved` removes a validator's consensus key.

## Validator Bonded

Upon successful first-time bonding of a new validator, we create a new `ValidatorSigningInfo` structure for the
now-bonded validator, which `StartHeight` of the current block.

If the validator was out of the validator set and gets bonded again, its new bonded height is set.

```go
onValidatorBonded(address sdk.ValAddress)

  signingInfo, found = GetValidatorSigningInfo(address)
  if !found {
    signingInfo = ValidatorSigningInfo {
      StartHeight         : CurrentHeight,
      IndexOffset         : 0,
      JailedUntil         : time.Unix(0, 0),
      Tombstone           : false,
      MissedBloskCounter  : 0
    } else {
      signingInfo.StartHeight = CurrentHeight
    }

    setValidatorSigningInfo(signingInfo)
  }

  return
```