5.15

🔮 Preview features

• Constructor mapping added to object mapping feature (#751)

Other

• The legal header at the top of each source file has been updated (#752)

5.14

⭐ New features

• Reauth moved from preview to general availability. (#744)
• Introduction of Security and Topology notification categories. (#738)
• Introduction of Bolt 5.4 (Introduced to Neo4j in server version 5.13) and TELEMETRY message. (#735
  • The driver can opt out of telemetry collection using ConfigBuilder.WithTelemetryDisabled().
  • Telemetry is only collected when connecting to aura and is limited to which APIs were used to create a transaction.

⚠️ Bug fixes

• All cursors belonging to a transaction are now invalidated if an error invalidates any of the transaction's queries. (#737)
  • If the initial exception was ignored, this could result in undefined behavior, but now will result in a TransactionTerminatedException; Any further interaction with any constituent results from the transaction will throw this error.

What's Changed

• Improve transaction timeout docs by @robsdedude in #731
• Add support for Bolt 5.4 and API Telemetry. by @thelonelyvulpes in #735
• docfx doc generation by @RichardIrons-neo4j in #736
• Add security and topology notification types by @RichardIrons-neo4j in #738
• Transaction error handling by @thelonelyvulpes in #737
• Tidying and minor refactoring by @RichardIrons-neo4j in #740
• Refactor the sprawl of driver and connection configs by @thelonelyvulpes in #730
• 5.14 version increment for next release by @thelonelyvulpes in #741
• Move auth to general availability by @thelonelyvulpes in #744
• Clean up folders by @thelonelyvulpes in #745

Full Changelog: 5.13.0...5.14.0

5.13.0

🔮 Preview Feature: Record to Object Mapping

This new feature allows records to be mapped to objects simply and without endless boilerplate. Please see this discussion for full details and instructions.

🔮 New convenience methods in preview

The following extension methods have been added in order to make code that deals with the IRecord and IEntity (implemented by both INode and IRelationship) interfaces more readable - for example, when writing custom mapping code. The Neo4j.Driver.Preview.Mapping namespace must be referenced to use these methods.

IRecord.AsObject<T>()

Invokes the mapping functionality and returns an instance of T mapped from the record. T must have a parameterless constructor.

IRecord.GetValue<T>(string key)

Gets the value of the given key from the record, converting it to the given type. For example, the code record["name"].As<string>() becomes record.GetValue<string>("name").

IRecord.GetXXXX(string key)

This is a group of extension methods for the most commonly used primitive types: GetString, GetInt, GetLong, GetDouble, GetFloat and GetBool. These just call GetValue<T> for the type named in the method name, so record["name"].As<string>() becomes record.GetString("name").

IEntity.GetValue<T>(string key)

Gets the value of the given key from the entity, converting it to the given type. For example, the code entity["name"].As<string>() becomes entity.GetValue<string>("name").

IEntity.GetXXXX(string key)

The same group of methods as IRecord.GetXXXX, but for an entity.

IRecord.GetEntity(string key)

Gets the IEntity identified by the given key from the record. When combined with the other methods, this can lead to more readable code that gets values from entities within records, so for example this code:

var name = record["person"].As<IEntity>().Properties["name"].As<string>();

becomes:

var name = record.GetEntity("person").GetString("name");

5.12.0

🚀 Optimization

• ExecutableQuery performance enhancement: Remove a server round-trip for IDriver.ExecutableQuery API Docs.

🔬 Experimental/Preview changes

• Changes to the re-auth functionality allow for catering to a wider range of use cases including simple password rotation.
• All re-auth-related namespaces have been moved to preview - previously some did not have this, although the classes therein would not have been usable.
• The OnTokenExpiredAsync method in the IAuthTokenManager interface was removed, and a new HandleSecurityExceptionAsync method was added in its place.
• The ExpirationBased method in AuthTokenManagers was renamed to Bearer, and a new Basic method was added to cater for password rotation.

5.11.0

What's Changed

• minor cleanups by @RichardIrons-neo4j in #718
• Round sub-milliseconds up to the next milliseconds on transaction timeout by @RichardIrons-neo4j in #720
• [5.11] Zoned date time fixes by @thelonelyvulpes in #715

5.10.0

No changes.

5.9.0

⭐ New Features

• Support for bolt protocol 5.3 which adds bolt_agent metadata so that the server knows which driver is connecting (#706).
• Re-authentication (in preview) (#689)
  Allows for handling expiring authentication (backwards compatible) as well as session scoped authentication (requires neo4j server version 5.5+).
  We are actively looking for feedback: #705

📚 Docs

Mention performance impact of notification filtering (#703).

5.8.0

⭐ New Features

• The ExecuteQuery API has now been moved out of preview. This provides a much simpler way to execute queries directly at the driver level, with sessions, transactions and bookmarks handled automatically.

Examples

var queryOp = await driver
    .ExecutableQuery("MATCH (person:Person) RETURN person")
    .ExecuteAsync();

Query Execution Result

The result of executing a query in the way shown above is an EagerResult<T>, where T is the type of data returned from the query. In the simplest case, this will be an IReadOnlyList<IRecord>, which is a fully materialized list of the records returned by the query. Other types of results can be used by using the fluent API exposed by the IExecutableQuery type, for example:

var queryOp = await driver
    .ExecutableQuery("MATCH (person:Person) RETURN person")
    .WithMap(r => r["person"].As<INode>()["name"].As<string>())
    .WithFilter(s => s.StartsWith("A"))
    .ExecuteAsync();

With this method, the return type will be EagerResult<IReadonlyList<string>>. Multiple .WithMap and .WithFilter calls may be chained together. Note that filtering is performed locally here so it should not be used in place of doing filtering on the server.

There is also a .WithReduce method, to be used as follows:

var queryOp = await driver
    .ExecutableQuery("MATCH (person:Person) RETURN person")
    .WithMap(r => r["person"].As<INode>()["age"].As<int>())
    .WithReduce(() => 0, (r, n) => r + n)
    .ExecuteAsync();

This will result in an EagerResult<int>, with the Result property containing the sum of all the ages.

Custom processing of the record stream can be done by using the .WithStreamProcessor method:

var queryOp = await driver
    .ExecutableQuery("MATCH (person:Person) RETURN person")
    .WithStreamProcessor(
        async stream =>
        {
            double total = 0;
            int count = 0;

            await foreach(var record in stream)
            {
                var age = record["person"].As<INode>()["age"].As<double>();
                total += age;
                count++;
            }

            return total / count;
        })
    .ExecuteAsync();

Here we simply supply a delegate, which will be called, passing a parameter of type IAsyncEnumerable<IRecord>. The value returned from this delegate will be an EagerResult<double>, with the Result property containing the average age.

Parameters can also be specified using the fluent interface, as follows.

var paramQuery = await driver
    .ExecutableQuery("MATCH (p:Person) WHERE p.name = $name RETURN p")
    .WithParameters(new { name = "Tom Hanks" })
    .WithMap(r => r["p"].As<INode>()["name"].As<string>())
    .ExecuteAsync();

5.7.0

🔬 Experimental/Preview changes

• the Neo4j.Driver.Experimental namespace has been renamed to Neo4j.Driver.Preview. This will be a compile-time breaking change for any code using this namespace. No functionality has been changed.

⭐ New Features

• ⭐ Introduce IDriver.TryVerifyConnectivityAsync
  • #693 #See issue

⭐ Notifications Updates #691

Introduce better notifications, and configuration(Docs).

NotificationSeverity

Introduce NotificationSeverity enum represents to represent a notification's severity level.

Severities:

• Warning
• Information
• Unknown

5.7 API Doc

NotificationCategory

Introduce NotificationCategory enum represents to represent a notification's category.

Categories:

• Hint
• Unrecognized
• Unsupported
• Performance
• Deprecation
• Generic
• Unknown

5.7 API Doc

Notification

The INotification interface extended with 4 new properties:

• NotificationSeverity SeverityLevel
• string RawSeverityLevel
• NotificationCategory Category
• string RawCategory

The Raw prefixed properties return an unparsed string representation returned by the server.
In case of an unrecognised values, both SeverityLevel and Category will be Unknown.
This may happen if a new value is introduced in a future server version and a previous driver version does not support it.
Additionally, Unknown may be returned when driver communicates with a server version that does not supply these values.

Deprecation ⚠️

The Severity property has been deprecated in favour of the RawSeverityLevel property.

5.7 API Doc

NotificationConfig

Introduce INotificationConfig type has been introduced to allow notification preferences management.
By default, the server determines what notifications are provided to the driver.
However, user can set a minimum severity level and/or a set of disabled notification categories to manage its expectations.
This feature is only supported on Bolt protocol version 5.2(Introduced in server 5.7) and above.

Both the Config and the SessionConfig support this new configuration, configured with builders:

• ConfigBuilder.WithNotificationsDisabled 5.7 API Doc
• ConfigBuilder.WithNotifications 5.7 API Doc
• SessionConfigBuilder.WithNotificationsDisabled 5.7 API Doc
• SessionConfigBuilder.WithNotifications 5.7 API Doc

Introduce Severity(API Docs) & Category(API Docs) enums for configuration.

Notification Configuration Hierarchy

Servers will assess which notifications to emit based on a hierarchy, using the most recently declared values.

using var driver = GraphDatabase.Driver(Neo4jUrl, AuthToken, cb => cb.WithNotificationsDisabled());
using var session = driver.AsyncSession();
...
var summary = await cursor.ConsumeAsync();
// No notifications should be emitted.
// This is useful for helping the server optimize operations as the server doesn't need to assess for any notifications.
// Notifications are not sent over the wire too meaning less data! 
Debug.Assert(summary.Notifications.Count() == 0); 

Severity configuration sets the minimum level of a notification, while category confugration is used to disable a category.

using var driver = GraphDatabase.Driver(Neo4jUrl, AuthToken, cb => cb.WithNotifications(Severity.Warning, null));
using var session = driver.AsyncSession(scb => scb.WithNotifications(null, new []{Category.Performance}));
...
var summary = await cursor.ConsumeAsync();
// no Information or performance notifications emitted.
Debug.Assert(summary.Notifications.Count(x => 
        x.NotificationCategory == NotificationCategory.Performance ||
        x.NotificationSeverity == NotificationSeverity.Information) == 0); 

if you require to enable a previously disabled categories for a session you can emit it from disabledCategories parameter.

using var driver = GraphDatabase.Driver(Neo4jUrl, AuthToken, cb => cb.WithNotifications(null, new []{Category.Performance}));
using var session = driver.AsyncSession(scb => scb.WithNotifications(null, new Category[]{}));
...
var summary = await cursor.ConsumeAsync();
// Notifications can contain anything again!

Bolt

This update includes support for both 5.1 and 5.2 versions. The latter is required for the full support of the new notification updates.

5.6.0

No changes.