Package org.jetbrains.mps.openapi.persistence

Interface DataSource

All Known Subinterfaces:

MultiStreamDataSource, StreamDataSource

All Known Implementing Classes:

NullDataSource

public interface DataSource

Represents a location of the model data sources to build models. For example it can be based on files, internet content, database content, etc. NB: Must not contain any information on the storage format specifics -- all that belongs to the ModelFactory. For implementation consider extending jetbrains.mps.extapi.persistence.DataSourceBase.

Method Summary

Modifier and Type	Method	Description
void	addListener(DataSourceListener listener)	Registers listeners who need to be notified about changes in the underlying data source.
String	getLocation()	Yields a string representation for the location of the data source (if applicable)
long	getTimestamp()	Retrieves the last modification timestamp.
default DataSourceType	getType()	Defines a data source type for this kind of data sources.
boolean	isReadOnly()	TODO Makes sense only with API which introduce changes to the DataSource.
void	removeListener(DataSourceListener listener)

Method Detail

getLocation

@NotNull
String getLocation()

Yields a string representation for the location of the data source (if applicable)

addListener

void addListener(@NotNull
                 DataSourceListener listener)

Registers listeners who need to be notified about changes in the underlying data source. It is the responsibility of the DataSource to detect such updates and notify the listeners.

removeListener

void removeListener(@NotNull
                    DataSourceListener listener)

getTimestamp

long getTimestamp()

Retrieves the last modification timestamp. The timestamp should reliably reflect all external changes to the data source.

Returns:

0 if timestamp is not supported for the source, or -1 if the source is dead (like when file is deleted)

isReadOnly

boolean isReadOnly()

TODO Makes sense only with API which introduce changes to the DataSource. Currently it is incomplete. Usually there is a possibility to edit DataSource. For examples please see StreamDataSource.

Returns:

whether this data source can be changed.

getType

@Nullable
default DataSourceType getType()

Defines a data source type for this kind of data sources. The data source type notion is strongly associated with the possibility to provide DataSourceFactory and ModelFactory custom mappings. See DataSourceFactoryRuleService and ModelFactoryService for the implementation details.

Returns:

the unique data source type for this instance of data source if the developer wants others to be able to change the default behavior of this data source (register with the same key) or if he desires to associate this data source with some specific model factory.