ElementHandler (Starjava TTOOLS API)

java.lang.Object
- uk.ac.starlink.ttools.votlint.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()

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(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(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 atts)`	Sets this handler's attributes.
`void`	`startElement()`	Called after the attributes have been set and checked.
`java.lang.String`	`toString()`
`void`	`warning(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 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(java.lang.String msg)
```
    Writes an info message through the context.
    
    Parameters:
    
    msg - message
  - warning
```
public void warning(java.lang.String msg)
```
    Writes a warning message through the context.
    
    Parameters:
    
    msg - message
  - error
```
public void error(java.lang.String msg)
```
    Writes an error message through the context.
    
    Parameters:
    
    msg - message
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object

Class ElementHandler

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

ElementHandler

Method Detail

configure

setAncestry

getAncestry

getRef

getName

setAttributes

getAttribute

startElement

endElement

characters

registerChildName

getContext

info

warning

error

toString