Groovy and Grails Training

Curriculum

1 Installation and introduction to groovy

• Installing sdkman
• Installing groovy development kit using sdkman
• Understanding the various tools like groovyc, groovy shell and groovy console
• Writing very basic commands on the groovy shell
• How groovy compares to other JVM languages like Java

2 Variables & Operators

• Defining variables using the ‘def’ keyword
• Dynamic typing
• Explicitly defining data types for a variable
• Arithmetic, relational, logical operators
• Elvis and spaceship operators in groovy

3 Functions

• Defining functions in groovy
• Function with implicit and explicit returns
• Default arguments in functions
• Closures
• Functional programming in groovy
• Functions that take groovy map as argument

4 Branching & Looping

• ‘if’ , ‘if-else if-else’ selection statements for branching
• The groovy ‘switch’ statement to achieve branching
• Looping using ‘while’ and ‘for’
• ‘break’ and ‘continue’ statements

5 Object oriented programming

• Classes and objects
• Difference between instance variables and static variables.
• Instance and static functions
• Constructors
• Groovy bean class
• On demand encapsulation of object attributes in groovy
• Operator overloading in groovy classes
• Composition
• Inheritance
• Abstract classes
• Interfaces
• Traits
• Organizing groovy code in packages
• Default packages imported in groovy code

6 Collections

• Using the List data type of groovy
• Functional programming on list data structure using groovy closures
• Meta programming on list data structure
• Map data structure in groovy and various operations on a map

7 Exception handling

• Flow of a program in the event of an exception thrown in the program
• Exception handling using try-catch
• Defining custom exceptions and throwing them
• The finally block
• How groovy exception handling is different from java exception handling

8 Metaprogramming

• Meta Object protocol (MOP)
• MetaClass
• Adding dynamic methods to build in groovy classes at run time
• Adding dynamic methods in custom groovy classes at run time

9 Builders

• Introduction to the builder pattern
• Designing domain specific language (DSL) to initialize objects in groovy
• JSON builder
• Object graph builder
• Other builders available in the groovy programming language

10 Introduction and installation of grails

• Install grails 3.x latest version using sdkman
• Create your first grails project and open it in an IDE of your choice that has grails support
• Understanding the dependency management and build system
• Tour of the grails documentation

11 Model layer

• Introduction to ORM
• Grails ORM models and how to define them
• Connecting grails project to a MYSQL database
• ‘constraints’ closure
• ‘mapping’ closure
• GORM model relationships - one to one, one to many, many to many
• GORM saving, updating, deleting entities
• Querying for GORM entities using dynamic finders, createCriteria and detached where
• Handling model schema changes using database migration plugin

12 Controllers

• Defining a grails controller
• Defining actions in a controller
• Mapping of urls to controllers and actions in the controller
• Sending model from action to views
• Redirecting to views
• Storing flash messages
• Implicit request object
• Data binding of incoming request data - To parameters in the action function, command objects
• Handling file uploads

13 View layer

• Introduction to groovy server pages (GSP)
• GSP ‘if’, ‘else’, ‘elseif’ branching tags
• GSP looping using the ‘each’ tag
• Layouting gsp pages
• GSP form tags
• Static resource management tags
• Link tags
• GSP tags for displaying the model errors
• Using GSP tags as method calls
• Internationalization support

14 Service layer

• Writing business logic in service component of grails
• Introduction to the Dependency injection (DI)
• Injecting service components in other service components and controller components
• Transaction support in grails services

15 Profiles

• Purpose behind profiles
• Introduction to web services and REST
• REST profile in grails
• Introducing other built in profiles in grails

16 Other common web concerns

• Declaring constraints in model classes
• Validation on the constraints
• Sharing constraints between multiple classes
• Cookies
• Http Sessions
• Creating interceptors
• Building CRUD interfaces using scaffolding in grails

17 Testing

• Introduction to the testing framework and test support in grails
• Writing unit tests for grails services
• Writing integration tests for complex business scenarios
• Introduction to functional testing