Package uk.ac.starlink.ttools.votlint

Class ElementHandler

  • Direct Known Subclasses:
    DataHandler, ParamHandler, StreamHandler, StreamingHandler, TableHandler, TdHandler, TrHandler
    public class ElementHandler
extends java.lang.Object
    Provides checking of a VOTable element during a SAX parse. There is one ElementHandler for each element encountered by the SAX parser; it is manipulated chiefly by the VotLintContentHandler which calls various methods on it in a controlled sequence as its life cycle progresses to handle the current state of the parse. Element-specific subclasses should generally override only the startElement(), endElement() and characters(char[], int, int) methods, which are invoked by the ContentHandler's similarly named methods.

    The checking done by an ElementHandler does not attempt to repeat or replace that done by validating against a DTD, it provides additional semantic checks based on what it knows about VOTables.

    Since:
    7 Apr 2005
    Author:
    Mark Taylor (Starlink)

    • Constructor Summary

      Constructors 
      Constructor Description
      ElementHandler()  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void characters​(char[] ch, int start, int length)
      Called when character content is found in the element.
      void configure​(java.lang.String localName, VotLintContext context)
      Sets this handler up ready for use.
      void endElement()
      Called when the element has ended.
      void error​(VotLintCode code, java.lang.String msg)
      Writes an error message through the context.
      Ancestry getAncestry()
      Returns an object containing the family relationships of this handler.
      java.lang.String getAttribute​(java.lang.String name)
      Returns the value of a named attribute.
      VotLintContext getContext()
      Returns this handler's context.
      java.lang.String getName()
      Returns the localName for this element.
      ElementRef getRef()
      Returns a reference for this element.
      void info​(VotLintCode code, java.lang.String msg)
      Writes an info message through the context.
      void registerChildName​(ElementRef child, java.lang.String name)
      Called to indicate that a child of this element has a "name" attribute.
      void setAncestry​(Ancestry ancestry)
      Sets the ancestry of this handler.
      void setAttributes​(java.util.Map<java.lang.String,​java.lang.String> atts)
      Sets this handler's attributes.
      void startElement()
      Called after the attributes have been set and checked.
      java.lang.String toString()  
      void warning​(VotLintCode code, java.lang.String msg)
      Writes a warning message through the context.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Constructor Detail

      • ElementHandler

        public ElementHandler()

    • Method Detail

      • configure

        public void configure​(java.lang.String localName,
                      VotLintContext context)
        Sets this handler up ready for use. Must be called before most of the other methods can be used.
        Parameters:
        localName - local name of the element this handler knows about
        context - lint context

      • setAncestry

        public void setAncestry​(Ancestry ancestry)
        Sets the ancestry of this handler.
        Parameters:
        ancestry - family values

      • getAncestry

        public Ancestry getAncestry()
        Returns an object containing the family relationships of this handler. This will only return a non-null value while the element is active (between its startElement and endElement calls). An ancestry object should not be used outside of this context.
        Returns:
        ancestry

      • getRef

        public ElementRef getRef()
        Returns a reference for this element.
        Returns:
        reference

      • getName

        public java.lang.String getName()
        Returns the localName for this element.
        Returns:
        element name

      • setAttributes

        public void setAttributes​(java.util.Map<java.lang.String,​java.lang.String> atts)
        Sets this handler's attributes.
        Parameters:
        atts - name -> value map representing this element's attributes

      • getAttribute

        public java.lang.String getAttribute​(java.lang.String name)
        Returns the value of a named attribute.
        Parameters:
        name - attribute name
        Returns:
        attribute value

      • startElement

        public void startElement()
        Called after the attributes have been set and checked. The default implementation does nothing.

      • endElement

        public void endElement()
        Called when the element has ended. The default implementation does nothing.

      • characters

        public void characters​(char[] ch,
                       int start,
                       int length)
        Called when character content is found in the element. The default implementation does nothing.

      • registerChildName

        public void registerChildName​(ElementRef child,
                              java.lang.String name)
        Called to indicate that a child of this element has a "name" attribute.
        Parameters:
        child - child element
        name - value of child's name attribute

      • getContext

        public VotLintContext getContext()
        Returns this handler's context.
        Returns:
        context

      • info

        public void info​(VotLintCode code,
                 java.lang.String msg)
        Writes an info message through the context.
        Parameters:
        code - message identifier
        msg - message text

      • warning

        public void warning​(VotLintCode code,
                    java.lang.String msg)
        Writes a warning message through the context.
        Parameters:
        code - message identifier
        msg - message text

      • error

        public void error​(VotLintCode code,
                  java.lang.String msg)
        Writes an error message through the context.
        Parameters:
        code - message identifier
        msg - message text

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object