Realm Xamarin  v0.80.0
Realm for Xamarin
Public Member Functions | Static Public Member Functions | Public Attributes | Properties | List of all members
Realm Class Reference

A Realm instance (also referred to as a realm) represents a Realm database. More...

Inherits IDisposable.

Public Member Functions

RealmResults< dynamic > All (string className)
 Get a view of all the objects of a particular type. More...
 
RealmResults< T > All< T > ()
 Extract an iterable set of objects for direct use or further query. More...
 
Transaction BeginWrite ()
 Factory for a write Transaction. Essential object to create scope for updates. More...
 
void Close ()
 Closes the Realm if not already closed. Safe to call repeatedly. Note that this will close the file. Other references to the same database on the same thread will be invalidated. More...
 
dynamic CreateObject (string className)
 Factory for a managed object in a realm. Only valid within a Write transaction. More...
 
CreateObject< T > ()
 Factory for a managed object in a realm. Only valid within a Write transaction. More...
 
void Dispose ()
 Dispose automatically closes the Realm if not already closed. More...
 
override bool Equals (object obj)
 Generic override determines whether the specified System.Object is equal to the current Realm. More...
 
bool Equals (Realm other)
 Determines whether the specified Realm is equal to the current Realm. More...
 
override int GetHashCode ()
 Serves as a hash function for a Realm based on the core instance. More...
 
bool IsSameInstance (Realm other)
 Determines whether this instance is the same core instance as the passed in argument. More...
 
void Manage< T > (T obj)
 This realm will start managing a RealmObject which has been created as a standalone object. More...
 
RealmObject ObjectForPrimaryKey (string className, long id)
 Fast lookup of an object for dynamic use, from a class which has a PrimaryKey property. More...
 
RealmObject ObjectForPrimaryKey (string className, string id)
 Fast lookup of an object for dynamic use, from a class which has a PrimaryKey property. More...
 
ObjectForPrimaryKey< T > (long id)
 Fast lookup of an object from a class which has a PrimaryKey property. More...
 
ObjectForPrimaryKey< T > (string id)
 Fast lookup of an object from a class which has a PrimaryKey property. More...
 
delegate void RealmChangedEventHandler (object sender, EventArgs e)
 Handler type used by RealmChanged More...
 
bool Refresh ()
 Update a Realm and outstanding objects to point to the most recent data for this Realm. This is only necessary when you have a Realm on a thread without a runloop that needs manual refreshing. More...
 
void Remove (RealmObject obj)
 Removes a persistent object from this realm, effectively deleting it. More...
 
void RemoveAll (string className)
 Remove all objects of a type from the realm. More...
 
void RemoveAll ()
 Remove all objects of all types managed by this realm. More...
 
void RemoveAll< T > ()
 Remove all objects of a type from the realm. More...
 
void RemoveRange< T > (RealmResults< T > range)
 Remove objects matching a query from the realm. More...
 
void Write (Action action)
 Execute an action inside a temporary transaction. If no exception is thrown, the transaction will automatically be committed. More...
 
Task WriteAsync (Action< Realm > action)
 Execute an action inside a temporary transaction on a worker thread. If no exception is thrown, the transaction will automatically be committed. More...
 

Static Public Member Functions

static void DeleteRealm (string databasePath)
 Deletes all files associated with a realm. More...
 
static void DeleteRealm (RealmConfiguration configuration)
 Deletes all the files associated with a realm. Hides knowledge of the auxiliary filenames from the programmer. More...
 
static Realm GetInstance (string databasePath)
 Factory for a Realm instance for this thread. More...
 
static Realm GetInstance (RealmConfiguration config=null)
 Factory for a Realm instance for this thread. More...
 

Public Attributes

bool IsClosed => SharedRealmHandle.IsClosed
 Checks if database has been closed. More...
 

Properties

RealmConfiguration Config [get]
 Gets the RealmConfiguration that controls this realm's path and other settings. More...
 
RealmChangedEventHandler RealmChanged
 Triggered when a realm has changed (i.e. a transaction was committed). More...
 
RealmSchema Schema [get]
 Gets the RealmSchema instance that describes all the types that can be stored in this Realm. More...
 

Detailed Description

A Realm instance (also referred to as a realm) represents a Realm database.

Warning: Realm instances are not thread safe and can not be shared across threads You must call GetInstance on each thread in which you want to interact with the realm.

Member Function Documentation

§ All()

RealmResults<dynamic> All ( string  className)

Get a view of all the objects of a particular type.

Parameters
classNameThe type of the objects as defined in the schema.

Because the objects inside the view are accessed dynamically, the view cannot be queried into using LINQ or other expression predicates.

Returns
A RealmResults that without further filtering, allows iterating all objects of className, in this realm.

Referenced by Realm.RemoveAll().

§ All< T >()

RealmResults<T> All< T > ( )

Extract an iterable set of objects for direct use or further query.

Template Parameters
TThe Type T must be a RealmObject.
Returns
A RealmResults that without further filtering, allows iterating all objects of class T, in this realm.
Type Constraints
T :RealmObject 

Referenced by Realm.RemoveAll< T >().

§ BeginWrite()

Transaction BeginWrite ( )

Factory for a write Transaction. Essential object to create scope for updates.

using (var trans = realm.BeginWrite()) { var rex = realm.CreateObject<Dog>(); rex.Name = "Rex"; trans.Commit(); }

Returns
A transaction in write mode, which is required for any creation or modification of objects persisted in a Realm.

Referenced by Realm.Write().

§ Close()

void Close ( )

Closes the Realm if not already closed. Safe to call repeatedly. Note that this will close the file. Other references to the same database on the same thread will be invalidated.

References Realm.Dispose().

§ CreateObject()

dynamic CreateObject ( string  className)

Factory for a managed object in a realm. Only valid within a Write transaction.

Returns
A dynamically-accessed Realm object.
Parameters
classNameThe type of object to create as defined in the schema.

If the realm instance has been created from an un-typed schema (such as when migrating from an older version of a realm) the returned object will be purely dynamic. If the realm has been created from a typed schema as is the default case when calling

Realm.GetInstance()

the returned object will be an instance of a user-defined class, as if created by

Realm.CreateObject<T>()

.

Referenced by Realm.CreateObject< T >().

§ CreateObject< T >()

T CreateObject< T > ( )

Factory for a managed object in a realm. Only valid within a Write transaction.

Using CreateObject is more efficient than creating standalone objects, assigning their values, then using Manage because it avoids copying properties to the realm.

Template Parameters
TThe Type T must be a RealmObject.
Returns
An object which is already managed.
Exceptions
RealmOutsideTransactionExceptionIf you invoke this when there is no write Transaction active on the realm.
Type Constraints
T :RealmObject 
T :new() 

References Realm.CreateObject().

§ DeleteRealm() [1/2]

static void DeleteRealm ( string  databasePath)
static

Deletes all files associated with a realm.

Parameters
databasePath

References RealmConfiguration.ConfigWithPath(), and RealmConfiguration.DefaultConfiguration.

§ DeleteRealm() [2/2]

static void DeleteRealm ( RealmConfiguration  configuration)
static

Deletes all the files associated with a realm. Hides knowledge of the auxiliary filenames from the programmer.

Parameters
configurationA configuration which supplies the realm path.

References Realm.Schema.

§ Dispose()

void Dispose ( )

Dispose automatically closes the Realm if not already closed.

References Realm.Equals().

Referenced by Realm.Close().

§ Equals() [1/2]

override bool Equals ( object  obj)

Generic override determines whether the specified System.Object is equal to the current Realm.

Parameters
objThe System.Object to compare with the current Realm.
Returns
true if the Realms are functionally equal.

Referenced by Realm.Dispose().

§ Equals() [2/2]

bool Equals ( Realm  other)

Determines whether the specified Realm is equal to the current Realm.

Parameters
otherThe Realm to compare with the current Realm.
Returns
true if the Realms are functionally equal.

References Realm.Config, RealmConfiguration.Equals(), and Realm.IsClosed.

§ GetHashCode()

override int GetHashCode ( )

Serves as a hash function for a Realm based on the core instance.

Returns
A hash code for this instance that is suitable for use in hashing algorithms and data structures such as a hash table.

§ GetInstance() [1/2]

static Realm GetInstance ( string  databasePath)
static

Factory for a Realm instance for this thread.

Parameters
databasePathPath to the realm, must be a valid full path for the current platform, relative subdirectory, or just filename.

If you specify a relative path, sandboxing by the OS may cause failure if you specify anything other than a subdirectory.
Instances are cached for a given absolute path and thread, so you may get back the same instance.

Returns
A realm instance, possibly from cache.
Exceptions
RealmFileAccessErrorExceptionThrows error if the file system returns an error preventing file creation.

References RealmConfiguration.ConfigWithPath(), and RealmConfiguration.DefaultConfiguration.

Referenced by Realm.GetInstance(), and Realm.WriteAsync().

§ GetInstance() [2/2]

static Realm GetInstance ( RealmConfiguration  config = null)
static

Factory for a Realm instance for this thread.

Parameters
configOptional configuration.
Returns
A realm instance.
Exceptions
RealmFileAccessErrorExceptionThrows error if the file system returns an error, preventing file creation.

References RealmConfiguration.DefaultConfiguration, Realm.GetInstance(), and RealmConfiguration.ObjectClasses.

§ IsSameInstance()

bool IsSameInstance ( Realm  other)

Determines whether this instance is the same core instance as the passed in argument.

You can, and should, have multiple instances open on different threads which have the same path and open the same Realm.

Returns
true if this instance is the same core instance; otherwise, false.
Parameters
otherThe Realm to compare with the current Realm.

§ Manage< T >()

void Manage< T > ( obj)

This realm will start managing a RealmObject which has been created as a standalone object.

Template Parameters
TThe Type T must not only be a RealmObject but also have been processed by the Fody weaver, so it has persistent properties.
Parameters
objMust be a standalone object, null not allowed.
Exceptions
RealmInvalidTransactionExceptionIf you invoke this when there is no write Transaction active on the realm.
RealmObjectAlreadyManagedByRealmExceptionYou can't manage the same object twice. This exception is thrown, rather than silently detecting the mistake, to help you debug your code
RealmObjectManagedByAnotherRealmExceptionYou can't manage an object with more than one realm
Type Constraints
T :RealmObject 

§ ObjectForPrimaryKey() [1/2]

RealmObject ObjectForPrimaryKey ( string  className,
long  id 
)

Fast lookup of an object for dynamic use, from a class which has a PrimaryKey property.

Parameters
classNameName of class in dynamic situation.
idId to be matched exactly, same as an == search.
Returns
Null or an object matching the id.
Exceptions
RealmClassLacksPrimaryKeyExceptionIf the RealmObject class lacks an [PrimaryKey].

§ ObjectForPrimaryKey() [2/2]

RealmObject ObjectForPrimaryKey ( string  className,
string  id 
)

Fast lookup of an object for dynamic use, from a class which has a PrimaryKey property.

Parameters
classNameName of class in dynamic situation.
idId to be matched exactly, same as an == search.
Returns
Null or an object matching the id.
Exceptions
RealmClassLacksPrimaryKeyExceptionIf the RealmObject class lacks an [PrimaryKey].

§ ObjectForPrimaryKey< T >() [1/2]

T ObjectForPrimaryKey< T > ( long  id)

Fast lookup of an object from a class which has a PrimaryKey property.

Template Parameters
TThe Type T must be a RealmObject.
Parameters
idId to be matched exactly, same as an == search. An argument of type long works for all integer properties, supported as PrimaryKey.
Returns
Null or an object matching the id.
Exceptions
RealmClassLacksPrimaryKeyExceptionIf the RealmObject class T lacks an [PrimaryKey].
Type Constraints
T :RealmObject 

§ ObjectForPrimaryKey< T >() [2/2]

T ObjectForPrimaryKey< T > ( string  id)

Fast lookup of an object from a class which has a PrimaryKey property.

Template Parameters
TThe Type T must be a RealmObject.
Parameters
idId to be matched exactly, same as an == search.
Returns
Null or an object matching the id.
Exceptions
RealmClassLacksPrimaryKeyExceptionIf the RealmObject class T lacks an [PrimaryKey].
Type Constraints
T :RealmObject 

§ RealmChangedEventHandler()

delegate void RealmChangedEventHandler ( object  sender,
EventArgs  e 
)

Handler type used by RealmChanged

Parameters
senderThe Realm which has changed.
eCurrently an empty argument, in future may indicate more details about the change.

§ Refresh()

bool Refresh ( )

Update a Realm and outstanding objects to point to the most recent data for this Realm. This is only necessary when you have a Realm on a thread without a runloop that needs manual refreshing.

Returns
Whether the realm had any updates. Note that this may return true even if no data has actually changed.

§ Remove()

void Remove ( RealmObject  obj)

Removes a persistent object from this realm, effectively deleting it.

Parameters
objMust be an object persisted in this realm.
Exceptions
RealmInvalidTransactionExceptionIf you invoke this when there is no write Transaction active on the realm.
System.ArgumentNullExceptionIf you invoke this with a standalone object.

§ RemoveAll() [1/2]

void RemoveAll ( string  className)

Remove all objects of a type from the realm.

Parameters
classNameType of the objects to remove as defined in the schema.

References Realm.All().

§ RemoveAll() [2/2]

void RemoveAll ( )

Remove all objects of all types managed by this realm.

§ RemoveAll< T >()

void RemoveAll< T > ( )

Remove all objects of a type from the realm.

Template Parameters
TType of the objects to remove.
Type Constraints
T :RealmObject 

References Realm.All< T >().

§ RemoveRange< T >()

void RemoveRange< T > ( RealmResults< T >  range)

Remove objects matching a query from the realm.

Template Parameters
TType of the objects to remove.
Parameters
rangeThe query to match for.

§ Write()

void Write ( Action  action)

Execute an action inside a temporary transaction. If no exception is thrown, the transaction will automatically be committed.

Creates its own temporary transaction and commits it after running the lambda passed to action. Be careful of wrapping multiple single property updates in multiple Write calls. It is more efficient to update several properties or even create multiple objects in a single Write, unless you need to guarantee finer-grained updates.

realm.Write(() => { d = realm.CreateObject<Dog>(); d.Name = "Eddie"; d.Age = 5; });

Parameters
actionAction to perform inside a transaction, creating, updating or removing objects.

References Realm.BeginWrite().

§ WriteAsync()

Task WriteAsync ( Action< Realm action)

Execute an action inside a temporary transaction on a worker thread. If no exception is thrown, the transaction will automatically be committed.

Opens a new instance of this realm on a worker thread and executes action inside a write transaction. Realms and realm objects are thread-affine, so capturing any such objects in the action delegate will lead to errors if they're used on the worker thread.

await realm.WriteAsync(tempRealm => { var pongo = tempRealm.All<Dog>().Single(d => d.Name == "Pongo"); var missis = tempRealm.All<Dog>().Single(d => d.Name == "Missis"); for (var i = 0; i < 15; i++) { var pup = tempRealm.CreateObject<Dog>(); pup.Breed = "Dalmatian"; pup.Mum = missis; pup.Dad = pongo; } });

Parameters
actionAction to perform inside a transaction, creating, updating or removing objects.
Returns
A standard Task so it can be used by await.

References Realm.Config, and Realm.GetInstance().

Member Data Documentation

§ IsClosed

bool IsClosed => SharedRealmHandle.IsClosed

Checks if database has been closed.

Returns
True if closed.

Referenced by Realm.Equals().

Property Documentation

§ Config

RealmConfiguration Config
get

Gets the RealmConfiguration that controls this realm's path and other settings.

Referenced by Realm.Equals(), and Realm.WriteAsync().

§ RealmChanged

RealmChangedEventHandler RealmChanged
addremove

Triggered when a realm has changed (i.e. a transaction was committed).

§ Schema

RealmSchema Schema
get

Gets the RealmSchema instance that describes all the types that can be stored in this Realm.

Referenced by Realm.DeleteRealm().