com.db4o.config
Interface ObjectField

public interface ObjectField

configuration interface for fields of classes.

Examples: ../com/db4o/samples/translators.

Use the global Configuration object to configure db4o before opening an ObjectContainer.

Example:
Configuration config = Db4o.configure();
ObjectClass oc = config.objectClass("package.className");
ObjectField of = oc.objectField("fieldName"); of.rename("newFieldName"); of.queryEvaluation(false);

Method Summary

void	cascadeOnActivate(boolean flag) sets cascaded activation behaviour.
void	cascadeOnDelete(boolean flag) sets cascaded delete behaviour.
void	cascadeOnUpdate(boolean flag) sets cascaded update behaviour.
void	queryEvaluation(boolean flag) toggles query evaluation.
void	rename(java.lang.String newName) renames a field of a stored class.

Method Detail

cascadeOnActivate

public void cascadeOnActivate(boolean flag)

sets cascaded activation behaviour.

Setting cascadeOnActivate to true will result in the activation of the object attribute stored in this field if the parent object is activated.

The default setting is false.

Parameters:

flag - whether activation is to be cascaded to the member object.

See Also:

Why activation?, ObjectClass#cascadeOnActivate(), ObjectContainer#activate(),
Using callbacks

cascadeOnDelete

public void cascadeOnDelete(boolean flag)

sets cascaded delete behaviour.

Setting cascadeOnDelete to true will result in the deletion of the object attribute stored in this field on the parent object if the parent object is passed to ObjectContainer#delete().

Caution !
This setting will also trigger deletion of the old member object, on calls to ObjectContainer#set(). An example of the behaviour can be found in ObjectClass#cascadeOnDelete()

The default setting is false.

Parameters:

flag - whether deletes are to be cascaded to the member object.

See Also:

ObjectClass#cascadeOnDelete(), ObjectContainer#delete(),
Using callbacks

cascadeOnUpdate

public void cascadeOnUpdate(boolean flag)

sets cascaded update behaviour.

Setting cascadeOnUpdate to true will result in the update of the object attribute stored in this field if the parent object is passed to ObjectContainer#set().

The default setting is false.

Parameters:

flag - whether updates are to be cascaded to the member object.

See Also:

ObjectContainer#set(), ObjectClass#cascadeOnUpdate(), ObjectClass#updateDepth(),
Using callbacks

rename

public void rename(java.lang.String newName)

renames a field of a stored class.

Use this method to refactor classes.

Examples: ../com/db4o/samples/rename.

Parameters:

newName - the new fieldname.

queryEvaluation

public void queryEvaluation(boolean flag)

toggles query evaluation.

All fields are evaluated by default. Use this method to turn query evaluation of for specific fields.

Parameters:

flag - specify false to ignore this field during query evaluation.