IMessageHandler (MPS.Core (JetBrains MPS 2019.1.0))

All Known Subinterfaces:

IMessageList

All Known Implementing Classes:

ErrorsLoggingHandler, LogHandler
```
public interface IMessageHandler
```
Interface is a strategy for the IMessage handling

Field Summary

Fields
Modifier and Type Field Description

static IMessageHandler NULL_HANDLER
Null-safe handler which does nothing

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`default IMessageHandler`	`compose(IMessageHandler another)`
`void`	`handle(IMessage msg)`
`default IMessageHandler`	`restrict(MessageKind atLeastOfKind)`

- Field Detail
  - NULL_HANDLER
```
static final IMessageHandler NULL_HANDLER
```
    Null-safe handler which does nothing
- Method Detail
  - handle
```
void handle(@NotNull
            IMessage msg)
```
  - compose
```
default IMessageHandler compose(@NotNull
                                IMessageHandler another)
```
    Parameters:
    
    another - one more handler to pipe messages to
    
    Returns:
    
    composite message handler that pipes messages to both this and another.
  - restrict
```
default IMessageHandler restrict(@NotNull
                                 MessageKind atLeastOfKind)
```
    Parameters:
    
    atLeastOfKind - use MessageKind.ERROR to filter out warnings and info, use MessageKind.WARNING to show errors and warnings only. Use of MessageKind.INFORMATION makes no sense and effectively a no-op.
    
    Returns:
    
    a new handler that would receive messages of the specified or severer) kind only