FxContainer is the ONLY IoC Container written in JavaFX and specifically developed to be used in JavaFX applications. It is powerful, lightweight and 75K in footprint and open source. Project website: https://fxobjects.dev.java.net

1. JavaFX Dependency
Injection with
FxContainer
Presented by
Srikanth Shenoy
ObjectSource
Learn FxContainer in 10 minutes

2. Introduction
 Who am I?
 A hands-on architect
 Experienced and very knowledgeable in Java and
Java EE
 Authored a book on Struts
 Several articles on Java EE for leading journals
 Director of Enterprise Java Practice at
ObjectSource
 Creator of FxObjects and FxContainer framework

3. Introduction
 What is FxContainer? (Currently 1.0)
 Open source IoC container written in JavaFX.
 Meant specifically for Dependency Injection in
JavaFX applications
 Very much Spring-like
 Small footprint (< 75K)
 Sequence, Collection Support
 Mix Java and JavaFX wiring
 Learn FxContainer in 20 slides! (10 minutes)

4. IoC Container Landscape
 Spring
 Supports XML and Annotations based DI
 Supports Constructor & Setter Injection
 Guice
 Supports Annotations and API based DI
 Supports Constructor & Setter Injection
 PicoContainer and many more..

5. Why another IoC Container?
 Problems with existing IoC Containers (in the
context of JavaFX)
 JavaFX does not support annotations 
 Hence Guice leaves only programmatic DI option
 Xml DI with Spring works, but minimal jars > 1 MB
 Constructor Injection not supported in JavaFX
 Setter Injection is unnatural for JavaFX style
 JavaFX variables are written as public or public-init
 Writing setXYZ() method for variables feels artificial
 Nobody supports Sequence (the first class
JavaFX collection citizen)

6. Setter Injection
var finder = MovieFinder {
movieDao: MovieDao { }
}
 Dependency Injection with any other IoC
container needs a setter like this (Not Good)
public class MovieFinder {
public-init movieDao:MovieDao;
public function setMovieDao(dao:MovieDao) {
this.movieDao = dao;
}
}

7. Side effects of Setter Injection
 Init and Post-Init code that depends on
public-init variables will not work
 Classic Example – CustomNode.create()
 Called automatically in every UI
 Called immediately after init and post init
 No time to call setter methods
 If create() depends on objects injected by setter
injection, then it will fail !!

8. A Different Kind of Injection
 Constructor Injection is DURING memory
allocation
 Setter Injection is AFTER memory allocation
and object initialization
 JavaFX needs something in between the two
 We call it Init injection
 A DI based on Init Injection does not exist
 So we created it 
FxContainer is the ONLY IoC container that
provides Init Injection for JavaFX

9. FxContainer Core Concept
 Based on JavaFX Reflection and Init Injection
FXLocal.Context ctx = FXLocal.getContext();
//get the class
FXClassType clzType = ctx.findClass("org.fxobjects.MovieFinder");
FXObjectValue objValue = clzType.allocate(); //allocate memory
//get the variable-type
FXVarMember varMember = clzType.getVariable("movieDao");
//create the variable-value
FXValue varValue = ctx.mirrorOf(Some String or object);
//initialize the variable. Basis for FxContainer Init Injection
objValue.initVar(varMember, varValue);
objValue.initialize(); //Finally initialize the object

10. FxContainer Overview
 Uses Setter Injection for Java objects
 Uses Init Injection for JavaFX objects
 Can mix both Java and JavaFX objects
 Java objects can hold references to JavaFX
objects via interfaces
 Very Spring Like in configuration
 Powerful, Lightweight and Easy to use

11. FxContainer: Simple
Dependency Injection
<fxcontainer>
<fxobject name="movieFinder"
class="org.fxobjects.samples.fxcontainer.MovieFinderImpl">
<property name="someVar" value="Some random value"/>
<property name="javaHelper" ref="javaHelperObj"/>
<property name="jfxHelper" ref="jfxHelperVarObj"/>
</fxobject>
<fxobject name="movieLister"
class="org.fxobjects.samples.fxcontainer.MovieLister">
<property name="finder" ref="movieFinder"/>
</fxobject>
</fxcontainer>

12. FxContainer: Import XML
 Good for organizing large XML into smaller
logical chunks
<fxcontainer>
<import resource="/org/fxobjects/samples/abc.xml"/>
<fxobject name="movieFinder"
class="org.fxobjects.samples.fxcontainer.MovieFinderImpl">
<property name="someVar" value="Some random value"/>
<property name="javaHelper" ref="javaHelperObj"/>
<property name="jfxHelper" ref="jfxHelperVarObj"/>
</fxobject>
</fxcontainer>

13. FxContainer: Import Properties
 Good for Spring style ${ } substitutions
<fxcontainer>
<import resource="/org/fxobjects/samples/abc.properties"/>
<fxobject name="movieFinder"
class="org.fxobjects.samples.fxcontainer.MovieFinderImpl">
<property name="someVar" value=“${svr1Name} is ${svr1Status}"/>
<property name="javaHelper" ref=“${helperObj}"/>
<property name="jfxHelper" ref="jfxHelperVarObj"/>
</fxobject>
</fxcontainer>
 value and ref can be substituted

14. FxContainer: Wired Object
Attributes
 Wired Objects in FxContainer have the following defaults
(can be overridden)
 Every wired object is singleton
 Every wired object is lazily initialized (i.e on demand)
 There is no order of initialization (Although load order can be
specified for eagerly loaded objects)
 Init-method is called after all properties are injected
<fxcontainer>
<fxobject name="movieFinder"
class="org.fxobjects.samples.fxcontainer.MovieFinderImpl“ lazy-
init=“false” load-order=“1” init-method=“someMethod”>
..
</fxobject>
</fxcontainer>

15. FxContainer: Sequences
<fxcontainer>
<fxobject name="movieFinder"
class="org.fxobjects.samples.fxcontainer.MovieFinderImpl">
<property name="movieCodes">  Primitive Sequence
<sequence>
<entry value=“1" />
<entry value="2" />
</sequence>
</property>
<property name="movies">  Object Sequence
<sequence>
<entry ref="movie1"/>
<entry ref="movie2"/>
</sequence>
</property>
</fxobject>
</fxcontainer>

16. FxContainer: Lists and Sets
<fxcontainer>
<fxobject name="movieFinder"
class="org.fxobjects.samples.fxcontainer.MovieFinderImpl">
<property name="movieList">  Object LIST
<list> (or <set>)
<entry ref="movie1"/>
<entry ref="movie2"/>
</list>
</property>
<property name="movieCodes">  Primitive LIST
<list valueClass=“java.lang.Integer”>
<entry value=“1" />
<entry value="2" />
</list>
</property>
</fxobject>
</fxcontainer>

17. FxObjects Lists and Sets
(Contd.)
 Lists and Sets have to be initialized in their
parents with a new …..();
 valueClass attribute
 Optional in most cases
 Reason: One cannot tell from the xml value
attributed if a list is Integer, String, BigDecimal
etc.
 Needed for Java and JavaFX objects when
 value attribute is specified in xml AND
 List is not parameterized (always the case in JavaFX)

18. FxContainer: Maps
<fxcontainer>
<fxobject name="movieFinder"
class="org.fxobjects.samples.fxcontainer.MovieFinderImpl">
<property name="movieMap">  Object MAP
<map>
<entry keyRef=“stage1” valueRef="movie1"/>
</map>
</property>
<property name="movieCodes">  Primitive MAP
<map keyClass=“java.lang.String”
valueClass=“java.lang.Integer”>
<entry key=“Terminator 1” value=“1" />
<entry value=“Terminator 2" />
</map>
</property>
</fxobject>
</fxcontainer>
keyClass and valueClass are needed for Maps in JavaFX with key
and value specified. (since they cannot be parameterized) and

19. FxContainer: Startup
 Spring Like
var loader = ClasspathXmlContainerLoader {
resourceLocation: "/org/fxobjects/samples/my.xml“
}
var container:FxContainer = loader.load();
var mvLister:MovieLister =
container.getFxObject("movieLister") as MovieLister;
 FxContainer can be used the IoC container
with FxObjects or any other JavaFX
application independently
 Just include 2 jars – fxcontainer.jar and
fxobjects-util.jar in classpath

20. FxObjects & FxContainer:
Roadmap

21. Links
 Project site – https://fxobjects/dev.java.net
 FxContainer is a subproject of FxObjects
 Not a single person open source project
 FxObjects and FxContainer developed and supported
by ObjectSource (http://www.objectsource.com)
 Download, use, extend, redistribute, OEM
 Discussion Forums on project site
 Participation welcome
 Post ideas, questions, concerns, comments
 Contribute code