Package org.nuiton.jaxx.compiler.binding

Class DataSource

  • public class DataSource
extends Object
    Represents a Java expression which fires a PropertyChangeEvent when it can be determined that its value may have changed. Events are fired on a "best effort" basis, and events may either be fired too often (the value has not actually changed) or not often enough (the value changed but no event was fired).

    • Field Detail

      • log

        protected static final org.apache.logging.log4j.Logger log
        Logger

      • constantId

        protected final String constantId
        Constant id

    • Constructor Detail

      • DataSource

        public DataSource​(String id,
                  String constantId,
                  String source,
                  JAXXCompiler compiler,
                  List<JavaMethod> methods)
        Creates a new data source. After creating a DataSource, use compile() to cause it to function at runtime.
        Parameters:
        id - the DataSource's id
        constantId - the DataSource constant id
        source - the Java source code for the data source expression
        compiler - the current JAXXCompiler
        methods - where to store extra method to add to binding

    • Method Detail

      • getObjectCode

        public String getObjectCode()

      • showLog

        public boolean showLog()

      • compile

        protected boolean compile()
                   throws CompilerException,
                          IllegalStateException
        Compiles the data source expression and listener. This method calls methods in JAXXCompiler to add the Java code that performs the data source setup. Adding listeners to DataSource is slightly more complicated than with ordinary classes, because DataSource only exists at compile time. You must pass in a Java expression which evaluates to a PropertyChangeListener; this expression will be compiled and evaluated at runtime to yield the DataSource's listener.
        Returns:
        true if the expression has dependencies, false otherwise
        Throws:
        CompilerException - if a compilation error occurs
        IllegalStateException - if data source was already compiled

      • getOverrideIds

        public Set<String> getOverrideIds()

      • hasMethod

        public boolean hasMethod​(String methodName)

      • getAddMemberListenerCode

        public String getAddMemberListenerCode​(DefaultObjectHandler handler,
                                       String objectCode,
                                       String memberName,
                                       String propertyChangeListenerCode,
                                       JAXXCompiler compiler)
        Returns a snippet of Java code which will cause a PropertyChangeListener to be notified when the member's value changes. The PropertyChangeListener is provided in the form of a Java code snippet that evaluates to a listener object. For ordinary bound JavaBeans properties, the Java code returned is a simple call to addPropertyChangeListener. Fields and methods which do not actually fire PropertyChangeEvents when they change necessitate more complex code.
        Parameters:
        handler - Object handler (containts known events
        objectCode - Java code which evaluates to the object to which to add the listener *@param dataBinding the name of the data binding this listener is a part of
        memberName - the name of the field or method to listen to
        propertyChangeListenerCode - Java code which evaluates to a PropertyChangeListener
        compiler - the current JAXXCompiler
        Returns:
        Java code snippet which causes the listener to be added to the object

      • getMethodReturnType

        protected ClassDescriptor getMethodReturnType​(ClassDescriptor contextClass,
                                              MethodDescriptor method)
        Given a method from a given context class, try to obtain his method return type. Sometimes, the return type is unknown (generics can not be bind for example). As a fallback, we try if the context class is exactly the root context class of the compiler, replace it by the script method with same name on which we can have more chance to obtain a return type...
        Parameters:
        contextClass - the context class of the method
        method - the method
        Returns:
        the method return type
        Since:
        2.4.2