HistoryManager (OpenNMS 2022.1.1 API)

All Known Implementing Classes:

BundleContextHistoryManager
```
public interface HistoryManager
```
Common interface to handle the user's history.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`applyHistory(String fragment, GraphContainer container)`	Restores the given history represented by `fragementId`.
`void`	`deleteHistory()`	Deletes the history for all users.
`SavedHistory`	`getHistoryByFragment(String fragment)`	Returns the history object for the provided `fragment`.
`SavedHistory`	`getHistoryByUserId(String userId)`	Returns the history object for the provided `userId`.
`String`	`getHistoryFragment(String userId)`
`String`	`saveOrUpdateHistory(String userId, GraphContainer container)`	Saves the current state of the `GraphContainer` for the current `userId`.

- Method Detail
  - saveOrUpdateHistory
```
String saveOrUpdateHistory(String userId,
                           GraphContainer container)
```
    Saves the current state of the GraphContainer for the current userId. The returned String is the history fragment (hash).
    
    Parameters:
    
    userId - The user to save the history for
    
    container - The current GraphContainer
    
    Returns:
    
    the history fragment (hash) of the saved history
    
    See Also:
    
    getHistoryFragment(String)
  - applyHistory
```
void applyHistory(String fragment,
                  GraphContainer container)
```
    Restores the given history represented by fragementId. The GraphContainer represents the user's state, which does not require the userId.
    
    Parameters:
    
    fragment - The history fragment (history hash)
    
    container - The GraphContainer needed to actually apply the history.
  - getHistoryFragment
```
String getHistoryFragment(String userId)
```
  - getHistoryByFragment
```
SavedHistory getHistoryByFragment(String fragment)
```
    Returns the history object for the provided fragment.
  - getHistoryByUserId
```
SavedHistory getHistoryByUserId(String userId)
```
    Returns the history object for the provided userId.
  - deleteHistory
```
void deleteHistory()
```
    Deletes the history for all users.