Lift Framework 3.3.0-M1

The Lift Committers are pleased to announce the release of Lift 3.3.0-M1 on February 7th, 2018. This release is the first of three milestone releases for Lift 3.3.0. The next milestone release is tentatively scheduled for April 1st, 2018. As always, you can follow along with our progress in the GitHub Milestone View.

Please read below for the changes in this milestone.

Changes

Improvements

• (#1931) Some readme improvements courtesy of @kohrVid
• (#1935, #1936) Various performance improvements to lift-json courtesy of @chriswebster
• (#1938) Fixed issues with building the project in IntelliJ courtesy of @andreak

About Lift

The Lift Framework is a mature, advanced framework for the modern software engineer. There are Seven Things that set Lift apart from the other frameworks out there today: it's secure-by-default, developer-centric, scalable, capable of rich interactive behavior, modular, and designer-friendly. If you're new to Lift or interested in checking out what these things mean, we recommend checking out Simply Lift and The Lift Cookbook.

The Lift Mailing List is also a good resource for anyone to ask questions or just meet other Lift users. The Lift README is a good resource for figuring out how to use Lift in your project.

Lift Framework 3.2.0

The Lift Committers are pleased to announce the release of Lift 3.2.0 on January 27th, 2018. This release continues our new release cadence. This release has no code changes from the 3.2.0-RC1 release.

The Lift 3.2.0 release makes many notable improvements, but the biggest single theme throughout all the changes is that of improvement of Lift's failover and clustering story. This release, coupled with @joescii's lift-cluster module represents a giant leap forward in Lift's scalability story.

About Lift

The Lift Framework is a mature, advanced framework for the modern software engineer. There are Seven Things that set Lift apart from the other frameworks out there today: it's secure-by-default, developer-centric, scalable, capable of rich interactive behavior, modular, and designer-friendly. If you're new to Lift or interested in checking out what these things mean, we recommend checking out Simply Lift and The Lift Cookbook.

The Lift Mailing List is also a good resource for anyone to ask questions or just meet other Lift users. The Lift README is a good resource for figuring out how to use Lift in your project.

Changes

This release of Lift is composed of the following component releases:

• Lift 3.2.0-M1
• Lift 3.2.0-M2
• Lift 3.2.0-M3
• Lift 3.2.0-RC1

Below is a list of changes since Lift 3.1 organized by the type of change and sorted by the PR number.

New Features

(#1770) Comet Rehydration

Since Comets were first introduced in Lift, it's been the case that if the Lift app server got restarted in the middle of a user's session and comets were involved then the user would need to refresh their entire page to reconnect to the server and have their comets start working again. By default, Lift is kind enough to do this page refresh for the users. However, this is a less than ideal experience for obvious reasons.

Now, after over a year's worth of work, @joescii has delivered Comet Rehydration to the Lift Framework.

Comet Rehydration is an optional feature that, when enabled, allows a user's browser to seamlessly reconnect to the comets on the server without needing to reload the page in many circumstances. In cases where significant changes have been delivered to an application, reloading the entire page may still be desirable. However, when deploying small bug fixes to users Comet Rehydration is a useful tool to do so without interrupting their experience in your application.

There are a couple of prerequisites to use rehydration effectively. Specifically,

• The CometActors in your application should have a mechanism for reconstructing their intended state from cookies or by invoking methods on the client via paritalUpdate that will cause the client to transmit its current state to a new Comet.
• If there is a significant amount of client-side JavaScript interacting with the comet, it would be advisable to version the RPC calls between the client and server so that the client knows when a full page reload is required. Such versions could be incremented to indicate changes in the protocol between the Comet and the browser or indicate that the browser needs to reload the page to fetch new JavaScript that the comet depends on (for example, a new version of jQuery).

We encourage all Lift developers to take a closer look at Comet Rehydration. We believe it will significantly improve the user experience for end-users of Lift applications when implemented with the prerequisites described above.

To start using rehydration, add the following to your Boot.boot implementation:

LiftRules.enableCometRehydration()

(#1864) Add transform and flip methods to Box

Our Box data type has learned a few new tricks.

The new transform method allows callers to take a Box and, via PartialFunction, turn it into any other Box. If the PartialFunction fails, the original Box is returned.

Some examples:

// Returns Full("alternative") because the partial function covers the case.
Full("error") transform {
  case Full("error") => Full("alternative")
}

// Returns Full(1), this Full box unchanged, because the partial function doesn't cover the case.
Full(1) transform {
  case Full(2) => Failure("error")
}

// Returns this Failure("another-error") unchanged because the partial function doesn't cover the case.
Failure("another-error") transform {
  case Failure("error", Empty, Empty) => Full("alternative")
}

// Returns Full("alternative") for an Empty box since `partialFn` is defined for Empty
Empty transform {
  case Empty => Full("alternative")
}

// Returns Empty because the partial function is not defined for Empty
Empty transform {
  case Failure("error", Empty, Empty) => Full("alternative")
}

The new flip method allows callers to take a Box and, if it is an EmptyBox (which is an Empty or any sort of Failure), flip it into a Full with a specific type. If it is a Full, an Empty is returned.

Many thanks to @Bhashit for this contribution!

(#1866) New Optional Mongo Fields

@Bhashit made a number of additions to the optional mongo fields as a part of mongodb-record. Some fun additions that your code might benefit from include:

• OptionalCaseClassField
• OptionalJObjectField
• OptionalUUIDRefField
• OptionalObjectIdField

... and more! We've also deprecated some legacy field names and parameter names (e.g. rec is now owner) so you'll probably see some deprecation warnings crop up if you're using any of those.

(#1874) Support for HTTP patch method in RestHelper.

We now support the Patch verb when using RestHelper to build APIs. Also, as you would expect, there are XmlPatch and JsonPatch variants as there are with Get, Post, etc.

(#1893) ContainerVar serialization for anything Serializable

Lift has provided ContainerVar for awhile for storing values in the underlying container session. (This is as opposed to the SessionVar that stores things in Lift's session.) However, to use a ContainerVar you need to provide some sort of ContainerSerializer for the type that you're trying to serialize. Even though Lift has provided a handful of implementations for awhile, none of them would handle something as simple as Box[String].

@joescii was kind enough to add a ContainerSerializer that works for anything extending Serializable. This should give Lift developers using ContainerVar a much more "batteries included" experience.

(#1906) Snippet Timers

Page loading slowly and you're not sure what code to blame? Want to just report all snippet timings to a metrics system for monitoring? Snippet Timers are for you! Snippet Timers enable global, per-request, or per-session timing of Snippet execution throughout your Lift application. By default, we package a LoggingSnippetTimer that spits out these timings to the log system, but anything implementing the SnippetTimer interface can be provided.

To get started you'll need to invoke LiftRules.installSnippetTimer in Boot to enable the feature. For example, to enable the logging snippet timer globally, just add the following line:

LiftRules.installSnippetTimer(LoggingSnippetTimer)

If you're only interested in logging in certain sessions or requests, you'll still need to invoke installSnippetTimer at boot with the NoOpSnippetTimer to enable the feature. Then, to enable logging snippet timing at some point in a request invoke:

LiftRules.snippetTimer.get.map(_.request(LoggingSnippetTimer))

The logging snippet timer will be enabled for the duration of the request. You can also do the same for a session.

LiftRules.snippetTimer.get.map(_.session(LoggingSnippetTimer))

Improvements

• During this release cycle, we also formalized our support policy.
• (#1865) Ensure the server/port combo of the original request is preserved. This resolves bug #1794, wherein our snapshotting of the underlying request object during some async operations was incomplete. This periodically caused misbehavior that broke the ability to retrieve the host and path of the request being handled by the async operations.
• (#1868) @Bhashit contributed some very nice documentation about Dependency Injection in Lift.
• (#1871) Bumped our logback version. This shouldn't affect applications using Lift directly, since we treat the logback dependency as something the application using Lift will provide. However, we do recommend that, if you haven't, you also upgrade to 1.2.3 or higher to resolve a security issue.
• (#1888, #1881) Various lift-json performance improvements.
• (#1889) Implementation of LiftRulesGuardedSetting. This type will eventually replace everything in LiftRules declared as a var. The idea here is that we want to avoid folks from changing things in LiftRules at runtime. We do that in a bit of an ad-hoc way now, in the sense that some settings will blow up in your face if you attempt to do so, but moving forward the `...

Lift Framework 3.2.0-RC1

The Lift Committers are pleased to announce the release of Lift 3.2.0-RC1 on December 16th, 2017. This release is the first (and hopefully last) release candidate for Lift 3.2.0. We encourage all Lift Framework users to bump their applications to this version as quickly as possible, and to give us feedback on how it works for you.

Please read below for the changes in this milestone.

Changes

New Features

(#1770) Comet Rehydration

Since Comets were first introduced in Lift, it's been the case that if the Lift app server got restarted in the middle of a user's session and comets were involved then the user would need to refresh their entire page to reconnect to the server and have their comets start working again. By default, Lift is kind enough to do this page refresh for the users. However, this is a less than ideal experience for obvious reasons.

Now, after over a year's worth of work, @joescii has delivered Comet Rehydration to the Lift Framework.

Comet Rehydration is an optional feature that, when enabled, allows a user's browser to seamlessly reconnect to the comets on the server without needing to reload the page in many circumstances. In cases where significant changes have been delivered to an application, reloading the entire page may still be desirable. However, when deploying small bug fixes to users Comet Rehydration is a useful tool to do so without interrupting their experience in your application.

There are a couple of prerequisites to use rehydration effectively. Specifically,

• The CometActors in your application should have a mechanism for reconstructing their intended state from cookies or by invoking methods on the client via paritalUpdate that will cause the client to transmit its current state to a new Comet.
• If there is a significant amount of client-side JavaScript interacting with the comet, it would be advisable to version the RPC calls between the client and server so that the client knows when a full page reload is required. Such versions could be incremented to indicate changes in the protocol between the Comet and the browser or indicate that the browser needs to reload the page to fetch new JavaScript that the comet depends on (for example, a new version of jQuery).

We encourage all Lift developers to take a closer look at Comet Rehydration. We believe it will significantly improve the user experience for end-users of Lift applications when implemented with the prerequisites described above.

To start using rehydration, add the following to your Boot.boot implementation:

LiftRules.enableCometRehydration()

Bug Fixes

• (#1924) Correctly override list item markup in lift-markdown. This resolves an issue (#1810) where InlineParser would ignore custom decorators for list items. Thanks @ricsirigu for the fix!
• (#1930) Added a null guard to address tests that touch stateful features. Resoles an issue (#1929) where an alarming, but harmless NullPointerException would occur in tests that destroy a LiftSession. Hat tip to @joescii for spotting it and delivering the fix.
• (#1928) Add a configurable maxIdLength to mongo-record's string primary keys. Previously this was hard-coded to 12.

Improvements

N/A

About Lift

The Lift Framework is a mature, advanced framework for the modern software engineer. There are Seven Things that set Lift apart from the other frameworks out there today: it's secure-by-default, developer-centric, scalable, capable of rich interactive behavior, modular, and designer-friendly. If you're new to Lift or interested in checking out what these things mean, we recommend checking out Simply Lift and The Lift Cookbook.

The Lift Mailing List is also a good resource for anyone to ask questions or just meet other Lift users. The Lift README is a good resource for figuring out how to use Lift in your project.

Lift Framework 3.2.0-M3

The Lift Committers are pleased to announce the release of Lift 3.2.0-M3 on November 16th, 2017. This release is the third of three milestone releases for Lift 3.2.0. The first release candidate is tentatively scheduled for December 15th, 2017 with plans to finalize Lift 3.2 around the end of the year. As always, you can follow along with our progress in the GitHub Milestone View.

Please read below for the changes in this milestone.

Changes

New Features

(#1864) Add transform and flip methods to Box

Our Box data type has learned a few new tricks.

The new transform method allows callers to take a Box and, via PartialFunction, turn it into any other Box. If the PartialFunction fails, the original Box is returned.

Some examples:

// Returns Full("alternative") because the partial function covers the case.
Full("error") transform {
  case Full("error") => Full("alternative")
}

// Returns Full(1), this Full box unchanged, because the partial function doesn't cover the case.
Full(1) transform {
  case Full(2) => Failure("error")
}

// Returns this Failure("another-error") unchanged because the partial function doesn't cover the case.
Failure("another-error") transform {
  case Failure("error", Empty, Empty) => Full("alternative")
}

// Returns Full("alternative") for an Empty box since `partialFn` is defined for Empty
Empty transform {
  case Empty => Full("alternative")
}

// Returns Empty because the partial function is not defined for Empty
Empty transform {
  case Failure("error", Empty, Empty) => Full("alternative")
}

The new flip method allows callers to take a Box and, if it is an EmptyBox (which is an Empty or any sort of Failure), flip it into a Full with a specific type. If it is a Full, an Empty is returned.

Many thanks to @Bhashit for this contribution!

Bug Fixes

• (#1923) Validate that no-arg comet constructor doesn't exist before attempting backup constructor. This fixes a long-standing bug in Lift regarding Comet instantiation. Previously, if you had a comet that threw an exception in it's no-argument constructor we would unintentionally swallow that exception and attempt the backup, comet info constructor. Then we'd complain to the developer that the comet info constructor didn't exist. We're now a bit smarter about how we handle those errors, and check the Exception that the no-arg instantiation returns. If it's anything other than a "no such method" Exception, we'll re-throw immediately instead of trying the comet info constructor.

Improvements

• (#1921) @joescii shipped some minor tweaks to support session serialization with lift-cluster.
• (#1908) MetaProtoExtendedSession cookies can now be restricted to the context path of your application. Or, really, any path you want - though we're skeptical restricting your cookies to /bananas if your application isn't hosted at /bananas would really be that useful.

About Lift

The Lift Framework is a mature, advanced framework for the modern software engineer. There are Seven Things that set Lift apart from the other frameworks out there today: it's secure-by-default, developer-centric, scalable, capable of rich interactive behavior, modular, and designer-friendly. If you're new to Lift or interested in checking out what these things mean, we recommend checking out Simply Lift and The Lift Cookbook.

The Lift Mailing List is also a good resource for anyone to ask questions or just meet other Lift users. The Lift README is a good resource for figuring out how to use Lift in your project.

Lift Framework 3.1.1

This is a bugfix release to Lift 3.1.0 to fix a few bugs that were introduced in the 3.0.0 release and discovered only recently. The bug fixes we've shipped are described below. Please let us know if on the Mailing List if you have any issues.

Fixes

• (#1917) Consider LiftRules.cometCreation when building comets. This LiftRule became ignored by accident during the great comet upgrade of the 3.0 release. We've added the line back that was missing, and plan to back-port this fix to the 3.0 and the 3.1 series.
• (#1915) Provide context path to session reload handler. There was a subtle change in behavior in Lift 3.0 that caused bad things to happen when a Lift application was deployed under a context path in an application server (so, somewhere other than /) and that Lift application detected that the comet session had disappeared. In previous versions of Lift this would just reload the page. In Lift 3.0, we changed that behavior to take you to the root of your application. However, / is not always the root of the application. Now, we'll properly consider the context path when detecting what URL to send you to. This is, as always, customizable with LiftRules.noCometSessionCmd.

Lift Framework 3.0.2

This is a bugfix release to Lift 3.0.1 to fix a few bugs that were introduced in the 3.0.0 release and discovered only recently. The bug fixes we've shipped are described below. Please let us know if on the Mailing List if you have any issues.

Fixes

• (#1916) Consider LiftRules.cometCreation when building comets. This LiftRule became ignored by accident during the great comet upgrade of the 3.0 release. We've added the line back that was missing, and plan to back-port this fix to the 3.0 and the 3.1 series.
• (#1914) Provide context path to session reload handler. There was a subtle change in behavior in Lift 3.0 that caused bad things to happen when a Lift application was deployed under a context path in an application server (so, somewhere other than /) and that Lift application detected that the comet session had disappeared. In previous versions of Lift this would just reload the page. In Lift 3.0, we changed that behavior to take you to the root of your application. However, / is not always the root of the application. Now, we'll properly consider the context path when detecting what URL to send you to. This is, as always, customizable with LiftRules.noCometSessionCmd.

Lift Framework 3.2.0-M2

The Lift Committers are pleased to announce the release of Lift 3.2.0-M2 on September 15th, 2017. This release is the second of three milestone releases for Lift 3.2.0. The next milestone release is tentatively scheduled for November 15th, 2017 with plans to finalize Lift 3.2 around the end of the year. As always, you can follow along with our progress in the GitHub Milestone View.

Please read below for the changes in this milestone.

Changes

New Features

(#1906) Snippet Timers

Page loading slowly and you're not sure what code to blame? Want to just report all snippet timings to a metrics system for monitoring? Snippet Timers are for you! Snippet Timers enable global, per-request, or per-session timing of Snippet execution throughout your Lift application. By default, we package a LoggingSnippetTimer that spits out these timings to the log system, but anything implementing the SnippetTimer interface can be provided.

To get started you'll need to invoke LiftRules.installSnippetTimer in Boot to enable the feature. For example, to enable the logging snippet timer globally, just add the following line:

LiftRules.installSnippetTimer(LoggingSnippetTimer)

If you're only interested in logging in certain sessions or requests, you'll still need to invoke installSnippetTimer at boot with the NoOpSnippetTimer to enable the feature. Then, to enable logging snippet timing at some point in a request invoke:

LiftRules.snippetTimer.get.map(_.request(LoggingSnippetTimer))

The logging snippet timer will be enabled for the duration of the request. You can also do the same for a session.

LiftRules.snippetTimer.get.map(_.session(LoggingSnippetTimer))

(#1893) ContainerVar serialization for anything Serializable

Lift has provided ContainerVar for awhile for storing values in the underlying container session. (This is as opposed to the SessionVar that stores things in Lift's session.) However, to use a ContainerVar you need to provide some sort of ContainerSerializer for the type that you're trying to serialize. Even though Lift has provided a handful of implementations for awhile, none of them would handle something as simple as Box[String].

@joescii was kind enough to add a ContainerSerializer that works for anything extending Serializable. This should give Lift developers using ContainerVar a much more "batteries included" experience.

(#1866) New Optional Mongo Fields

@Bhashit made a number of additions to the optional mongo fields as a part of mongodb-record. Some fun additions that your code might benefit from include:

• OptionalCaseClassField
• OptionalJObjectField
• OptionalUUIDRefField
• OptionalObjectIdField

... and more! We've also deprecated some legacy field names and parameter names (e.g. rec is now owner) so you'll probably see some deprecation warnings crop up if you're using any of those.

Documentation

• (#1868) @Bhashit contributed some very nice documentation about Dependency Injection in Lift.
• During this release cycle, we also formalized our support policy.

Bug Fixes

• (#1911) Consider LiftRules.cometCreation when building comets. This LiftRule became ignored by accident during the great comet upgrade of the 3.0 release. We've added the line back that was missing, and plan to back-port this fix to the 3.0 and the 3.1 series.
• (#1903) Provide context path to session reload handler. There was a subtle change in behavior in Lift 3.0 that caused bad things to happen when a Lift application was deployed under a context path in an application server (so, somewhere other than /) and that Lift application detected that the comet session had disappeared. In previous versions of Lift this would just reload the page. In Lift 3.0, we changed that behavior to take you to the root of your application. However, / is not always the root of the application. Now, we'll properly consider the context path when detecting what URL to send you to. This is, as always, customizable with LiftRules.noCometSessionCmd.

Improvements

• (#1918) Logging improvements for various exceptions. @andreak had located a few spots that weren't properly printing the exception stack trace when exceptions were hit, and delivered a Quick Fix™ to that.
• (#1910) Clarification of LAPinger documentation.
• (#1909) Move template cache defaulting to LiftRules. This change addresses some confusing behavior in how Lift creates the default template cache. Previously, if you were running in production mode and the templateCache was set to Empty we would auto-magically create an InMemoryCache and use that instead. Due to the way this was written, this effectively meant that turning off template caching in production was impossible. With this change we moved where the default gets calculated so it's actually possible to turn off the template cache in production mode if you would like to do that.
• (#1907) Addition of onShutdown to buildRoundtrip. Previously, users of buildRoundtrip had no way to get notified that the underlying comet actor had been shut down. This meant that they had no way to really know if they could free resources that might be associated with that connection in their application level code. To address this, we've added an onShutdown argument to the buildRoundtrip function so developers can pass a handler when the underlying comet is actually shut down.
• (#1895) Make the servlet session ID configurable. Previously, Lift's servlet session identifier was hard-coded. This worked fine for a long time. However, recently we discovered that it doesn't play nice when used in conjunction with Jetty's Mongo persisted sessions plugin because of the $s in it. To resolve that, we've made it configurable through LiftRules.servletSessionIdentifier.
• (#1889) Implementation of LiftRulesGuardedSetting. This type will eventually replace everything in LiftRules declared as a var. The idea here is that we want to avoid folks from changing things in LiftRules at runtime. We do that in a bit of an ad-hoc way now, in the sense that some settings will blow up in your face if you attempt to do so, but moving forward the LiftRulesGuardedSetting is the way we're planning to standardize that behavior and make it more consistent.
• (#1888, #1881) Various lift-json performance improvements.

About Lift

The Lift Framework is a mature, advanced framework for the modern software engineer. There are Seven Things that set Lift apart from the other frameworks out there today: it's secure-by-default, developer-centric, scalable, capable of rich interactive behavior, modular, and designer-friendly. If you're new to Lift or interested in checking out what these things mean, we recommend checking out Simply Lift and The Lift Cookbook.

The Lift Mailing List is also a good resource for anyone to ask questions or just meet other Lift users. The Lift README is a good resource for figuring out how to use Lift in your project.

Lift Framework 3.2.0-M1

The Lift Committers are pleased to announce the release of Lift 3.2.0-M1 on July 23rd, 2017. This release is the first of three milestone releases for Lift 3.2.0. The next milestone release is tentatively scheduled for September 15th, 2017 with plans to finalize Lift 3.2 around the end of the year. As always, you can follow along with our progress in the GitHub Milestone View.

Please read below for the changes in this milestone.

Changes

• (#1874) Support for HTTP patch method in RestHelper. This PR adds support for a Patch verb when using RestHelper to build APIs. Examples on how to use this can be found in the Scaladocs for the new matcher. Also, as you would expect, there are XmlPatch and JsonPatch variants as there are with Get, Post, etc.
• (#1865) Ensure the server/port combo of the original request is preserved. This resolves bug #1794, wherein our snapshotting of the underlying request object during some async operations was incomplete. This periodically caused misbehavior that broke the ability to retrieve the host and path of the request being handled by the async operations.
• (#1871) Bumped our logback version. This shouldn't affect applications using Lift directly, since we treat the logback dependency as something the application using Lift will provide. However, we do recommend that, if you haven't, you also upgrade to 1.2.3 or higher to resolve a security issue.

About Lift

The Lift Framework is a mature, advanced framework for the modern software engineer. There are Seven Things that set Lift apart from the other frameworks out there today: it's secure-by-default, developer-centric, scalable, capable of rich interactive behavior, modular, and designer-friendly. If you're new to Lift or interested in checking out what these things mean, we recommend checking out Simply Lift and The Lift Cookbook.

The Lift Mailing List is also a good resource for anyone to ask questions or just meet other Lift users. The Lift README is a good resource for figuring out how to use Lift in your project.

Lift Framework 3.1.0

The Lift Committers are pleased to announce the release of Lift 3.1.0 on July 2nd, 2017. This release continues our new release cadence and marks the first final release in our new cadence. This release has no code changes from the 3.1.0-RC1 release.

About Lift

The Lift Framework is a mature, advanced framework for the modern software engineer. There are Seven Things that set Lift apart from the other frameworks out there today: it's secure-by-default, developer-centric, scalable, capable of rich interactive behavior, modular, and designer-friendly. If you're new to Lift or interested in checking out what these things mean, we recommend checking out Simply Lift and The Lift Cookbook.

The Lift Mailing List is also a good resource for anyone to ask questions or just meet other Lift users. The Lift README is a good resource for figuring out how to use Lift in your project.

Changes

This release of Lift is composed of the following component releases:

• Lift 3.1.0-M1
• Lift 3.1.0-M2
• Lift 3.1.0-M3
• Lift 3.1.0-RC1

Below is a list of changes since Lift 3.0 organized by the type of change and sorted by the PR number.

New Features

• (#1768) Improved handling of tuples in lift-json. Tuples can now be serialized and deserialized as heterogenous arrays in JSON instead of as objects. This feature is disabled by default to ensure we're not changing default behavior in Lift 3.1, but can be enabled by providing a Formats object with tuplesAsArrays set to true. The one caveat with this functionality is that it doesn't consistently support Scala primitives, so if you're using tuples inside a larger, more complex structure you'll want to use the Java boxed types instead of Scala primitives where applicable (so, java.lang.Integer instead of Int). However, if the tuple contains case classes you should be able to use primitives inside those without issue: this caveat only affects primitives directly in the tuple. The README for lift-json documents all of this, and Matt Farmer wrote a blog post demonstrating it in a more narrative style if that's more your thing.
• (#1813, #1824) Session-aware Lift and Scala Futures. Especially with Lift 3's enhanced support for futures in CSS bindings and RestHelper, folks would find themselves firing off futures that needed to do i18n or something else that required session access, only to have that session context missing when the future actually executed. @pdyraga added a new helper, LAFutureWithSession.withCurrentSession, aliased as S.sessionFuture, which can be used to create an LAFuture task that has access to the session. There is a similar helper, FutureWithSession.withCurrentSession, that will spawn a task as a Scala Future with access to the session. The resulting futures can be chained and combined with other futures and will preserve their session access. This includes all APIs in Scala's Future in Scala 2.12, as well.
• (#1845) Custom rendering of special Double values. Prior to M3, lift-json always serialized NaN, PositiveInfinity, and NegativeInfinity as their respective string values (NaN, -Infinity, Infinity). This is actually not correct JSON, as these are not supported JSON numeric values. Many if not most JSON parsers will choke on this output, including browser parsers. One notable exception is if anyone is evaling JSON as JavaScript directly---but this is a very unsafe practice. As of M3, we default to rendering these as null instead, and provide a new RenderSettings customization that allows you to switch back to the old rendering approach, or to switch to an approach that throws an exception if these special values are found (which can be paired with tryo to produce a Failure in these cases).
• (#1857) Addition of the BoxLogging helpers. The new BoxLogging helper provides functions for logging boxes and then continuing to operate on the box, allowing logging to become a fluent part of the Box interaction. It provides methods that can allow for logging empties and failures, or just failures. It also allows logging these to different log levels, and allows for different adapters to be applied.

Improvements

• @n4to4 was kind enough to fix some broken links in our readme.
• (#1791) Event return normalization. If handlers to liftVanilla.onEvent returned false, we'd just return that value. Now, we now check for the existence of event.preventDefault and trigger it and stopPropagation if the handler returned false. We also return that return that false value for older browsers to work with.
• (#1812, #1815, #1823) Full compatibility with Scala 2.12. Lift 3.0.1 was released with Scala 2.12 support, but there were still some pieces to put in place for proper continuous integration and release building before we could consider that complete. This is now done. Thanks to @SethTisue and @farmdawgnation for putting in some contortions to get this all in order.
• (#1817, #1822) lift-json has gained significant parser performance improvements, and is now competitive with the jawn parser in most of jawn's microbenchmarks, making it one of the fastest Scala JSON parsers across a variety of parsing scenarios.
• (#1819) The mongo Java driver has been updated to version 3.4.0.
• (#1829) The MongoDB Record module now supports the MongoDB Async API calls. Now, there are a handful of *Async methods on the MongoDB record implementation that will return Futures to the calling code, meaning you can now easily compose Mongo Record operations with other non-blocking code. Hat tip to @eltimn and @marekzebrowski for their work on this.
• (#1837, #1854) Removed FileInputStream and FileOutputStream usage. @eltimn moved much of Lift's internal usage of FileInputStream and FileOutputStream to their more GC-friendly java.nio equivalents. See this Cloudbees post for the GC impact of the old streams. This change should have no impact on your code. If you find yourself having to recompile your code to work with this change, please let us know on the mailing list, as this is meant to be a purely internal change.
• (#1838) Removed some deprecated rendering methods in lift-json.
• (#1839) Closer to jQuery independence. Lift 3.0.0 debuted a new liftVanilla provider of JavaScript functionality on the client with an eye towards removing the Lift jQuery dependency; unfortunately, that provider was somewhat incomplete. Amongst other things, loading it still required having jQuery loaded, or at least defined. We've removed this dependency now, and continue to work to make liftVanilla a fully functional replacement for the jquery-dependent functionality needed for core Lift operations.
• (#1853) Added Class caching for type hints in lift-json. This change should improve performance when the same type hint is seen multiple times by caching the Class instance we use for a particular type hint instead of invoking a class lookup each time.
• (#1862) Improve error messages when we can't find a correct implicit conversion for CSS transforms. When things went wrong while trying to resolve implicit conversions to make a working CSS transform, the compiler error generated was pretty opaque. With this change, we've improved that error message to be more friendly to people without a ton of Lift experience.

Bug Fixes

• (#1832) Fixed snippet class cache. Resolved a bug in how we cache snippet class instances that caused a performance hit when using the same snippet multiple times.
• (#1841) Fixed event extraction for page fragments. When event extraction was introduced in Lift 3, it did not take into account the possibility that a page fragment might be processed---for example, as a response to an AJAX request. As a result, in these cases, the events were extracted… But they were not re-transmitted through a separate channel. Instead, they were lost entirely. We now fix that, and page fragments with extracted events will properly reference the detached event handler code that will set those handlers up properly on the client.
• (#1842) Disabled event extraction for fixHtmlFunc. JsExps that handle HTML go through fixHtmlFunc, which is charged with preprocessing any embedded JS so it can be served correctly for client interpretation. Unfortunately, the interaction between this preprocessing and event extraction led to some broken and unexpected behavior. We're reasoning through a deeper fix, but in the meantime even when LiftRules.extractInlineJavaScript is enabled, fixHtmlFunc will not do event extraction.
• (#1844) Properly handle missing servlet http requests in buildDeferredFunction. Sometimes S.req returns a Req without a servlet HTTPRequest inside. Ergo, when code would call HttpRequest.snapshot in Req.snapshot, we would get a NullPointerException. To fix this, we modify currentReq in both definitions of buildDeferredFunction so that they filter out null requests. Shout out to first-time contributor @arigoldx!
• (#1852) **Always suspend...

Lift Framework 3.1.0-RC1

The Lift Committers are pleased to announce the release of Lift 3.1.0-RC1 on June 16, 2017. This release continues our new release cadence. This will be the final pre-release 3.1.0 build unless we find regressions or need to make critical fixes to the 3.1.0 line before declaring it final.

Provided we do not need to make an additional release candidate, this release will become the final 3.1.0 build at the end of June. For the latter half of the year, we'll start the release cycle over for 3.2.0. You can follow the milestone progress in the Github milestone view.

Below is a summary of the changes that have been made since 3.1.0-M3.

The following new features or improvements have been made in this release:

• (#1857) Addition of the BoxLogging helpers. The new BoxLogging helper provides functions for logging boxes and then continuing to operate on the box, allowing logging to become a fluent part of the Box interaction. It provides methods that can allow for logging empties and failures, or just failures. It also allows logging these to different log levels, and allows for different adapters to be applied.
• (#1862) Improve error messages when we can't find a correct implicit conversion for CSS transforms. When things went wrong while trying to resolve implicit conversions to make a working CSS transform, the compiler error generated was pretty opaque. With this change, we've improved that error message to be more friendly to people without a ton of Lift experience.

Additionally, the following bug fixes have been made in this release:

• (#1852) Always suspend Comet Requests before resuming them. When a container supports request suspension, we were first scheduling a function to resume the request on a different thread and then suspending the request. While the function was scheduled in the future, the fact that it was scheduled before the suspend had definitively occurred meant there were thread schedulings where the resume could occur before the suspend had executed, leading to exceptions. We now suspend the request before scheduling the resume.
• (#1844) Properly handle missing servlet http requests in buildDeferredFunction. Sometimes S.req returns a Req without a servlet HTTPRequest inside. Ergo, when code would call HttpRequest.snapshot in Req.snapshot, we would get a NullPointerException. To fix this, we modify currentReq in both definitions of buildDeferredFunction so that they filter out null requests. Shout out to first-time contributor @arigoldx!
• (#1861) Add special handling for UnavailableException in boot. This code adds special handling for javax.servlet.UnavailableException. Previously, if this exception was thrown during boot, we'd swallow it because we swallowed all exceptions during boot. However, this exception is an idiomatic way to signal a full abort to the Java Application Server running the application. From now on, we will log and re-throw this exception if we see it.
• (#1863) Resolve some issues with swallowing exceptions in lift-json. In some cases extraction in lift-json would go horribly wrong and swallow exceptions that occur during class instantiation. This was due to us failing to pass on an underlying exception when we run into these errors. That has now been fixed.
• (#1859) Fix LAFuture.collect/collectAll when sub-futures fail. Before, a single failed LAFuture rolled up in a collect or collectAll would cause the overall future to hang forever. We now properly fail the overall future if any contained future fails.
• (aeeac27) Some minor liftsh changes to deal with some build problems.

This release is immediately available on Maven Central. Please let us know what you think on the mailing list!