io.realm

Class RealmObjectSchema

java.lang.Object

io.realm.RealmObjectSchema

public abstract class RealmObjectSchema
extends Object

Class for interacting with the schema for a given RealmObject class. This makes it possible to inspect, add, delete or change the fields for given class.

If this RealmObjectSchema is retrieved from an immutable RealmSchema, this RealmObjectSchema will be immutable as well.

See Also:

RealmMigration

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	RealmObjectSchema.Function Function interface, used when traversing all objects of the current class and apply a function on each.

Method Summary

Modifier and Type	Method and Description
abstract RealmObjectSchema	addField(String fieldName, Class<?> fieldType, FieldAttribute... attributes) Adds a new simple field to the RealmObject class.
abstract RealmObjectSchema	addIndex(String fieldName) Adds an index to a given field.
abstract RealmObjectSchema	addPrimaryKey(String fieldName) Adds a primary key to a given field.
abstract RealmObjectSchema	addRealmListField(String fieldName, Class<?> primitiveType) Adds a new field that references a RealmList with primitive values.
abstract RealmObjectSchema	addRealmListField(String fieldName, RealmObjectSchema objectSchema) Adds a new field that contains a RealmList with references to other Realm model classes.
abstract RealmObjectSchema	addRealmObjectField(String fieldName, RealmObjectSchema objectSchema) Adds a new field that references another RealmObject.
String	getClassName() Returns the name of the RealmObject class being represented by this schema.
Set<String>	getFieldNames() Returns all fields in this class.
RealmFieldType	getFieldType(String fieldName) Returns the type used by the underlying storage engine to represent this field.
String	getPrimaryKey() Returns the name of the primary key field.
boolean	hasField(String fieldName) Tests if the class has field defined with the given name.
boolean	hasIndex(String fieldName) Checks if a given field has an index defined.
boolean	hasPrimaryKey() Checks if the class has a primary key defined.
boolean	isEmbedded() Returns true if objects of this type are considered "embedded".
boolean	isNullable(String fieldName) Checks if a given field is nullable i.e., it is allowed to contain null values.
boolean	isPrimaryKey(String fieldName) Checks if a given field is the primary key field.
boolean	isRequired(String fieldName) Checks if a given field is required i.e., it is not allowed to contain null values.
abstract RealmObjectSchema	removeField(String fieldName) Removes a field from the class.
abstract RealmObjectSchema	removeIndex(String fieldName) Removes an index from a given field.
abstract RealmObjectSchema	removePrimaryKey() Removes the primary key from this class.
abstract RealmObjectSchema	renameField(String currentFieldName, String newFieldName) Renames a field from one name to another.
abstract RealmObjectSchema	setClassName(String className) Sets a new name for this RealmObject class.
void	setEmbedded(boolean embedded) Converts the class to be embedded or not.
abstract RealmObjectSchema	setNullable(String fieldName, boolean nullable) Sets a field to be nullable i.e., it should be able to hold null values.
abstract RealmObjectSchema	setRequired(String fieldName, boolean required) Sets a field to be required i.e., it is not allowed to hold null values.
abstract RealmObjectSchema	transform(RealmObjectSchema.Function function) Runs a transformation function on each RealmObject instance of the current class.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getClassName

public String getClassName()

Returns the name of the RealmObject class being represented by this schema.

• When using a normal Realm this name is the same as the RealmObject class.
• When using a DynamicRealm this is the name used in all API methods requiring a class name.

Returns:

the name of the RealmObject class represented by this schema.

Throws:

IllegalStateException - if this schema defintion is no longer part of the Realm.

setClassName

public abstract RealmObjectSchema setClassName(String className)

Sets a new name for this RealmObject class. This is equivalent to renaming it.

Parameters:

className - the new name for this class.

Throws:

IllegalArgumentException - if className is null or an empty string, or its length exceeds 56 characters.

UnsupportedOperationException - if this RealmObjectSchema is immutable or from a synced Realm.

See Also:

RealmSchema.rename(String, String)

addField

public abstract RealmObjectSchema addField(String fieldName,
                                           Class<?> fieldType,
                                           FieldAttribute... attributes)

Adds a new simple field to the RealmObject class. The type must be one supported by Realm. See RealmObject for the list of supported types. If the field should allow null values use the boxed type instead e.g., Integer.class instead of int.class.

To add fields that reference other RealmObjects or RealmLists use addRealmObjectField(String, RealmObjectSchema) or addRealmListField(String, RealmObjectSchema) instead.

Parameters:

fieldName - name of the field to add.

fieldType - type of field to add. See RealmObject for the full list.

attributes - set of attributes for this field.

Returns:

the updated schema.

Throws:

IllegalArgumentException - if the type isn't supported, field name is illegal or a field with that name already exists.

UnsupportedOperationException - if this RealmObjectSchema is immutable or if adding a a field with FieldAttribute.PRIMARY_KEY attribute to a schema of a synced Realm.

addRealmObjectField

public abstract RealmObjectSchema addRealmObjectField(String fieldName,
                                                      RealmObjectSchema objectSchema)

Adds a new field that references another RealmObject.

Parameters:

fieldName - name of the field to add.

objectSchema - schema for the Realm type being referenced.

Returns:

the updated schema.

Throws:

IllegalArgumentException - if field name is illegal or a field with that name already exists.

UnsupportedOperationException - if this RealmObjectSchema is immutable.

addRealmListField

public abstract RealmObjectSchema addRealmListField(String fieldName,
                                                    RealmObjectSchema objectSchema)

Adds a new field that contains a RealmList with references to other Realm model classes.

If the list contains primitive types, use addRealmListField(String, Class) instead.

Parameters:

fieldName - name of the field to add.

objectSchema - schema for the Realm type being referenced.

Returns:

the updated schema.

Throws:

IllegalArgumentException - if the field name is illegal or a field with that name already exists.

UnsupportedOperationException - if this RealmObjectSchema is immutable.

addRealmListField

public abstract RealmObjectSchema addRealmListField(String fieldName,
                                                    Class<?> primitiveType)

Adds a new field that references a RealmList with primitive values. See RealmObject for the list of supported types.

Nullability of elements are defined by using the correct class e.g., Integer.class instead of int.class. Alternatively setRequired(String, boolean) can be used.

Example:

 
 // Defines the list of Strings as being non null.
 RealmObjectSchema schema = schema.create("Person")
     .addRealmListField("children", String.class)
     .setRequired("children", true)
 
 

If the list contains references to other Realm classes, use addRealmListField(String, RealmObjectSchema) instead.

Parameters:

fieldName - name of the field to add.

primitiveType - simple type of elements in the array.

Returns:

the updated schema.

Throws:

IllegalArgumentException - if the field name is illegal, a field with that name already exists or the element type isn't supported.

UnsupportedOperationException - if this RealmObjectSchema is immutable.

removeField

public abstract RealmObjectSchema removeField(String fieldName)

Removes a field from the class.

Parameters:

fieldName - field name to remove.

Returns:

the updated schema.

Throws:

IllegalArgumentException - if field name doesn't exist.

UnsupportedOperationException - if this RealmObjectSchema is immutable or for a synced Realm.

renameField

public abstract RealmObjectSchema renameField(String currentFieldName,
                                              String newFieldName)

Renames a field from one name to another.

Parameters:

currentFieldName - field name to rename.

newFieldName - the new field name.

Returns:

the updated schema.

Throws:

IllegalArgumentException - if field name doesn't exist or if the new field name already exists.

UnsupportedOperationException - if this RealmObjectSchema is immutable or for a synced Realm.

hasField

public boolean hasField(String fieldName)

Tests if the class has field defined with the given name.

Parameters:

fieldName - field name to test.

Returns:

true if the field exists, false otherwise.

addIndex

public abstract RealmObjectSchema addIndex(String fieldName)

Adds an index to a given field. This is the equivalent of adding the Index annotation on the field.

Parameters:

fieldName - field to add index to.

Returns:

the updated schema.

Throws:

IllegalArgumentException - if field name doesn't exist, the field cannot be indexed or it already has a index defined.

UnsupportedOperationException - if this RealmObjectSchema is immutable.

hasIndex

public boolean hasIndex(String fieldName)

Checks if a given field has an index defined.

Parameters:

fieldName - existing field name to check.

Returns:

true if field is indexed, false otherwise.

Throws:

IllegalArgumentException - if field name doesn't exist.

See Also:

Index

removeIndex

public abstract RealmObjectSchema removeIndex(String fieldName)

Removes an index from a given field. This is the same as removing the @Index annotation on the field.

Parameters:

fieldName - field to remove index from.

Returns:

the updated schema.

Throws:

IllegalArgumentException - if field name doesn't exist or the field doesn't have an index.

UnsupportedOperationException - if this RealmObjectSchema is immutable or of a synced Realm.

addPrimaryKey

public abstract RealmObjectSchema addPrimaryKey(String fieldName)

Adds a primary key to a given field. This is the same as adding the PrimaryKey annotation on the field. Further, this implicitly adds Index annotation to the field as well.

Parameters:

fieldName - field to set as primary key.

Returns:

the updated schema.

Throws:

IllegalArgumentException - if field name doesn't exist, the field cannot be a primary key or it already has a primary key defined.

UnsupportedOperationException - if this RealmObjectSchema is immutable or of a synced Realm.

removePrimaryKey

public abstract RealmObjectSchema removePrimaryKey()

Removes the primary key from this class. This is the same as removing the PrimaryKey annotation from the class. Further, this implicitly removes Index annotation from the field as well.

Returns:

the updated schema.

Throws:

IllegalArgumentException - if the class doesn't have a primary key defined.

UnsupportedOperationException - if this RealmObjectSchema is immutable or of a synced Realm.

setRequired

public abstract RealmObjectSchema setRequired(String fieldName,
                                              boolean required)

Sets a field to be required i.e., it is not allowed to hold null values. This is equivalent to switching between boxed types and their primitive variant e.g., Integer to int.

If the type of designated field is a list of values (not RealmObjects , specified nullability only affects its elements, not the field itself. Value list itself is always non-nullable.

Parameters:

fieldName - name of field in the class.

required - true if field should be required, false otherwise.

Returns:

the updated schema.

Throws:

IllegalArgumentException - if the field name doesn't exist, cannot have the Required annotation or the field already have been set as required.

UnsupportedOperationException - if this RealmObjectSchema is immutable.

See Also:

Required

setNullable

public abstract RealmObjectSchema setNullable(String fieldName,
                                              boolean nullable)

Sets a field to be nullable i.e., it should be able to hold null values. This is equivalent to switching between primitive types and their boxed variant e.g., int to Integer.

If the type of designated field is a list of values (not RealmObjects , specified nullability only affects its elements, not the field itself. Value list itself is always non-nullable.

Parameters:

fieldName - name of field in the class.

nullable - true if field should be nullable, false otherwise.

Returns:

the updated schema.

Throws:

IllegalArgumentException - if the field name doesn't exist, or cannot be set as nullable.

UnsupportedOperationException - if this RealmObjectSchema is immutable.

isRequired

public boolean isRequired(String fieldName)

Checks if a given field is required i.e., it is not allowed to contain null values.

Parameters:

fieldName - field to check.

Returns:

true if it is required, false otherwise.

Throws:

IllegalArgumentException - if field name doesn't exist.

See Also:

setRequired(String, boolean)

isNullable

public boolean isNullable(String fieldName)

Checks if a given field is nullable i.e., it is allowed to contain null values.

Parameters:

fieldName - field to check.

Returns:

true if it is required, false otherwise.

Throws:

IllegalArgumentException - if field name doesn't exist.

See Also:

setNullable(String, boolean)

isPrimaryKey

public boolean isPrimaryKey(String fieldName)

Checks if a given field is the primary key field.

Parameters:

fieldName - field to check.

Returns:

true if it is the primary key field, false otherwise.

Throws:

IllegalArgumentException - if field name doesn't exist.

See Also:

addPrimaryKey(String)

hasPrimaryKey

public boolean hasPrimaryKey()

Checks if the class has a primary key defined.

Returns:

true if a primary key is defined, false otherwise.

See Also:

PrimaryKey

getPrimaryKey

public String getPrimaryKey()

Returns the name of the primary key field.

Returns:

the name of the primary key field.

Throws:

IllegalStateException - if the class doesn't have a primary key defined.

getFieldNames

public Set<String> getFieldNames()

Returns all fields in this class.

Returns:

a list of all the fields in this class.

transform

public abstract RealmObjectSchema transform(RealmObjectSchema.Function function)

Runs a transformation function on each RealmObject instance of the current class. The object will be represented as a DynamicRealmObject.

There is no guarantees in which order the objects are returned.

Parameters:

function - transformation function.

Returns:

this schema.

Throws:

UnsupportedOperationException - if this RealmObjectSchema is immutable.

getFieldType

public RealmFieldType getFieldType(String fieldName)

Returns the type used by the underlying storage engine to represent this field.

Parameters:

fieldName - name of the target field.

Returns:

the underlying type used by Realm to represent this field.

isEmbedded

public boolean isEmbedded()

Returns true if objects of this type are considered "embedded". See RealmClass.embedded() for further details.

Returns:

true if objects of this type are embedded. false if not.

setEmbedded

public void setEmbedded(boolean embedded)

Converts the class to be embedded or not.

A class can only be marked as embedded if the following invariants are satisfied:

• The class is not allowed to have a primary key defined.
• All existing objects of this type, must have one and exactly one parent object already pointing to it. If 0 or more than 1 object has a reference to an object about to be marked embedded an IllegalStateException will be thrown.

Throws:

IllegalStateException - if the class could not be converted because it broke some of the Embedded Objects invariants.

See Also:

RealmClass.embedded()