Preview of upcoming Grails 3.0 release at SpringOne 2GX 2014

1. Grails 3.0 Preview
By Graeme Rocher
© 2014 SpringOne 2GX. All rights reserved. Do not distribute without permission.

2. Agenda
§ State of Nation
§ What’s planned for Grails 2.4?
§ What’s planned for Grails 3.0?
§ Summary / Q & A

3. State of Nation
§ Grails 2.4.3 most recent version
§ Grails 2.3.x line at 2.3.9
§ Hundreds of bugs fixed in the last 3
months
§ More than 1,100 plugins now for
Grails

4. !
Grails 2.4
What’s new?
2.4

5. Grails 2.4
• Spring 4.0 Upgrade
• Java 8 Support
• Groovy 2.3 Upgrade
• Improved @CompileStatic Support
• Asset Pipeline Plugin
• Moduralization of Codebase
• Hibernate Goodies
• GORM & GSP Standalone
5
32..04

6. Spring 4.0 / 4.1
• Native GroovyBeanDefinitionReader
(ported from BeanBuilder)
– https://spring.io/blog/2014/03/03/groovy-bean-
configuration-in-spring-framework-4
• Spring Web Socket
– http://grails.org/plugin/spring-websocket
6

7. Groovy 2.3
• Traits
• Java 8
• Implicit closure coercion
• Lots more!
• http://docs.codehaus.org/
display/GROOVY/Groovy
+2.3+release+notes
7

8. Other Notable Updates
• Java 8 Support
• Hibernate 4.3.5 now default
• AspectJ 1.8 with Java 8 support
• Eclipse Aether 1.0.0
• Fewer Overall Dependencies
8

9. Modularization
9
grails-web
grails-web-mvc
grails-web-sitemesh
grails-web-common
grails-web-servlet
grails-web-gsp grails-web-jsp
grails-core
grails-encoder
grails-project-api
grails-validation

10. Asset Pipeline Plugin
• Resources replaced with Asset
Pipeline
– https://github.com/bertramdev/asset-pipeline/
wiki/Why-asset-pipeline-over-grails-
resources-plugin
• Full documentation
– http://bertramdev.github.io/asset-pipeline/
• Many thanks to David Estes!
10

11. Standalone
• GORM for Hibernate 4 in Spring Boot
– https://spring.io/guides/gs/accessing-data-gorm/
• GORM for MongoDB in Spring Boot
– https://spring.io/guides/gs/accessing-data-gorm-mongodb/
• GSP standalone
– https://github.com/grails/grails-boot/tree/master/sample-apps/
gsp
11

12. @GrailsCompileStatic
• Grails-aware version of Groovy’s @CompileStatic
12
import
grails.compiler.*
!
@GrailsCompileStatic
class
BookController
{
…
}

13. Maven-style Dependency Management
• Use management block to declare managed dependencies
13
!
management
{
dependency
"commons-­‐logging:commons-­‐
logging:1.1.3"
}

14. Hibernate Subqueries
• Perform nested “in” or “notIn” sub queries that span domain
classes using where queries:
14
def
employees
=
Employee.where
{
region.continent
in
['APAC',
"EMEA"]
}.id()
!
def
results
=
Sale.where
{
employee
in
employees
&&
total
>
50000
}.employee.list()

15. Hibernate Correlated Subqueries
• Declare aliases using “def” for cross query references:
15
def
query
=
Employee.where
{
def
em1
=
Employee
exists
Sale.where
{
def
s1
=
Sale
def
em2
=
employee
return
em2.id
==
em1.id
}.id()
}
def
results
=
query.list()

16. Hibernate Column Readers/Writers
• Implement custom column readers and writers to transform
data when written or read from the database.
16
Name
{
String
title
static
class
mapping
=
{
title
write:'UPPER(?)',
read:'REPEAT(title,
2)'
}
}

17. Hibernate 4 in Unit Tests (Coming Soon)
• Test Hibernate 4 interaction in unit tests
17
import
grails.test.mixin.hibernate.*
!
@TestMixin(HibernateTestMixin)
class
PersonSpec
extends
Specification{
void
setupSpec()
{
hibernateDomain([Person])
}
…
}

18. GORM for MongoDB 3.0
• Support for MongoDB 2.6
• GeoJSON type support
• Maps of entities
• Full Text Search
• Projections using Aggregations
• Size queries (sizeEq, sizeLt etc.)
• Spring Boot
– https://spring.io/guides/gs/accessing-data-
gorm-mongodb/
18

19. New Maven Plugin 2.4.3
• Upgraded to Maven 3.1+
• Rewritten to use Aether for dependency resolution as per
recommendations
• Can now be used with multiple versions of Grails:
19
<configuration>
<grailsVersion>2.3.8</grailsVersion>
</configuration>

20. Grails 2.4.x TODOs
• Grails 2.4.4 - Out Soon
• Spring Security Core 2.0 GA
• Spring Web Flow Plugin Update
• Bug Fixes
20
2.4

21. !
Q & A
Grails 2.4
2.4

22. !
The Future
Grails 3.0
3.0

23. Grails 3.0: Goals
• Embrace Gradle
• Abstract Packaging / Deployment
• Reach outside the Servlet Container
• App Profiles: Netty, Servlet, Batch,
Hadoop
• Deployment with run-app / runnable
JARs
• Extend the reach of Grails
23
33..00

24. Grails 3.0: Goals
• Build on Spring Boot
• Plugin System & Events
• Support Multi Project Builds
• Support Micro Services
• Remove Bloat
• Reduce Dependencies
24
33..00

25. Spring IO Platform Reprise
25
XD GRAILS
Bootable, Minimal, Ops-Ready
INTEGRATION BATCH BIG DATA WEB
Jobs, Steps, Ingestion, Channels, Adapters, Export, Controllers, REST,
SPRING CORE
FRAMEWOR SECURIT GROOV REACTO
DATA
RELATIONA NON-BOOT
IO
IO

26. Spring IO Platform
26
Grails
Spring IO Platform
Spring XD
Spring Foundation
Apps
Spring Boot
3rd Party Dependencies

27. Spring IO & Grails
• What does Spring IO bring to Grails?
– Standardised dependency management
– Published BOMs for use with Maven & Gradle
– Foundational libraries
– See more http://docs.spring.io/platform/docs/current/
reference/htmlsingle/
27
dependencies
{
compile
'commons-­‐lang:commons-­‐lang'
}

28. Gradle
• Deprecate existing build system
• Replace with Gradle build
• Easier now everything is forked in 2.3.x
• All the flexibility of a powerful build
system
• Separate build plugins can provide
Gradle extensions
28

29. Plugin Delineation
29
Grails.sh
Static void main
Gradle Build
test-app
console
Forked Grails Runtime
run-app shell
Codegen
Plugins
Build Time
Plugins
Runtime
Plugins

30. Gradle
• Allow Micro or Monolith Applications
• Multi-Project Plugin Architectures
• Run individual sub projects
• Or run as a whole
30

31. !
Demo
Grails 3.0
Gradle
3.0

32. Spring Boot
• Grails 3.0 to be built on Spring Boot
• Boot to handle
• Embedded servers
• Runnable JARs
• WAR packaging
• Scripting / Micro Services
32

33. Why Spring Boot?
• Handles Fat JAR and embedding
• Already supports different runtimes
• Includes monitoring and health
checks
• Grails can take advantage of Boot
auto configuration
33

34. Boot Powered Micro Services
34
@Grab("com.h2database:h2:1.3.173")
import
grails.persistence.*
!
@Entity
@Resource(uri='/books')
class
Book
{
String
title
}

35. !
Demo
Grails 3.0
Micro Services
3.0

36. Deprecations / Removals
• Servlet 2.5 support (no web.xml)
• Gant & Current Build System
• GDoc - Replaced by AsciiDoctor
• Integration Tests - Replaced by more
Mixins
• Converters / Codecs plugins -
Replaced by Groovy extensions
• Filters - Replaced by new mechanism
36

37. Servlet 3.0 only and no web.xml
• Thanks to Spring Boot, new servlets and filters can just be
Spring beans
37
!
def
doWithSpring
=
{
characterEncodingFilter(
CharacterEncodingFilter)
{
encoding
='utf-­‐8'
}
}

38. Simplification
• Removed
– UrlMappingsFilter
– GrailsDispatcherServlet
– SimpleGrailsController
– Sitemesh Filter
38

39. Old Grails 2.x Flow
39
GrailsPageFilter UrlMappingsFilter
GrailsDispatherServlet
Decorate Request Forward Request
GrailsController
Delegate Request

40. Grails 3.0 Flow
• GrailsDispatcherSerlvet 50 lines of code in 3.x,
but 545 lines in 2.x
40
DispatcherServlet
GrailsController
Delegate Request

41. Benefits of Simplification
• Less code to maintain
• Better performance
• Better integration with Spring
• Fewer dependencies
• commons-fileupload gone
• No internal forwarding
41

42. Evolution of Metaprogramming
42
Grails 1.x Grails 2.x Grails 3.x
Runtime
Metaprogramming
(ExpandoMetaClass)
Compile time
Metaprogramming
(AST Transforms)
Traits &
Transforms

43. Grails 3.0 & Groovy Traits
• Most logic previously added via AST transforms will now be
added by Traits
– (Cases not possible as Trait done with transforms)
43
trait
Controller
{
…
def
withFormat(Closure
callable)
{
…
}
}

44. Application Profiles
• Each profile will have distinct plugins, runtimes and
packaging (JAR, WAR etc.)
44
!
$
grails
create-­‐app
myapp
-­‐-­‐profile=netty
$
cd
myapp
$
grails
package
$
java
-­‐jar
target/myapp.jar
!

45. Application Profiles
• Extensible profiles with an API exposing structure
• Profile specific commands (run, package, test)
• Profile specific plugins
• Profile specific project templates and file templates (code
generators) backed by Git
• Community maintained profiles and core profiles
45

46. Profile Repository
• All Profiles managed by git
• Profiles checked out locally and periodically updated
• Profiles wrap code generation infrastructure
46
$
grails
create-­‐controller
foo
!
Profile
.getCurrentProfile()
.getCommand('create-­‐controller')
.execute(
'foo'
)

47. Grails 3.0: Challenges
• Compatibility
– Plugins
– Build System
• Modularization
– Servlet API independence
– Refactoring
47
3.0

48. !
Q & A
Grails 3.0
3.0

49. Stay Connected.
!
!
!
!
Web: grails.org
StackOverflow: http://stackoverflow.com/tags/grails
Twitter: twitter.com/grailsframework
LinkedIn: http://linkedin.com/groups/Grails-User-Group-39757
Google+: https://plus.google.com/communities/
109558563916416343008