uk.ac.starlink.votable

## Class Namespacing

- java.lang.Object
- - uk.ac.starlink.votable.Namespacing

-     public abstract class Namespacing
      extends java.lang.Object

  Determines how namespaces are handled in VOTable documents. The static `getInstance()` method provides an object which encapsulates the default namespacing policy.
  Since:
    1 Sep 2009
  Author:
    Mark Taylor

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static Namespacing` | `LAX` Interpret likely-looking elements in any namespace as VOTable ones.
    `static Namespacing` | `NONE` No namespace awareness; any namespacing will probably confuse parser.
    `static java.lang.String` | `POLICY_PROP` Name of system property which determines namespacing policy used.
    `static Namespacing` | `STRICT` Only elements in namespaces with VOTable URIs are significant.

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `Namespacing(java.lang.String name)` Constructor.

  - ### Method Summary

    All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `abstract void` | `configureSAXParserFactory(javax.xml.parsers.SAXParserFactory spfact)` Performs any necessary configuration of the namespacing capabilities of a given parser factory for use with this namespacing policy.
    `static Namespacing` | `getInstance()` Returns the default Namespacing instance.
    `java.lang.String` | `getVOTagName(org.w3c.dom.Element el)` Returns the VOTable tagname for an XML element as present in a DOM.
    `abstract java.lang.String` | `getVOTagName(java.lang.String namespaceURI, java.lang.String localName, java.lang.String qName)` Returns the VOTable tagname for an XML element as encountered by a SAX parser.
    `void` | `setInstance(Namespacing instance)` Sets the default instance.
    `java.lang.String` | `toString()` Returns the name of this namespacing policy.

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### POLICY_PROP

          public static final java.lang.String POLICY_PROP

      Name of system property which determines namespacing policy used. Property name is "votable.namespacing". Possible values are "`none`", "`lax`", "`strict`" or the classname of a `Namespacing` implementation which has a no-arg constructor.
      See Also:
        Constant Field Values

    - #### NONE

          public static final Namespacing NONE

      No namespace awareness; any namespacing will probably confuse parser.

    - #### LAX

          public static final Namespacing LAX

      Interpret likely-looking elements in any namespace as VOTable ones.

    - #### STRICT

          public static final Namespacing STRICT

      Only elements in namespaces with VOTable URIs are significant.

  - ### Constructor Detail

    - #### Namespacing

          public Namespacing(java.lang.String name)

      Constructor.
      Parameters:
        `name` - concise human-readable name describing this policy

  - ### Method Detail

    - #### configureSAXParserFactory

          public abstract void configureSAXParserFactory(javax.xml.parsers.SAXParserFactory spfact)

      Performs any necessary configuration of the namespacing capabilities of a given parser factory for use with this namespacing policy.
      Parameters:
        `spfact` - factory to configure

    - #### getVOTagName

          public abstract java.lang.String getVOTagName(java.lang.String namespaceURI,
                                                        java.lang.String localName,
                                                        java.lang.String qName)

      Returns the VOTable tagname for an XML element as encountered by a SAX parser. The return value is a bare string which may be compared to one of the VOTable element names ignoring namespaces; for instance a return value of "TABLE" indicates that this is a VOTable TABLE element.

      The parameters have the same meanings, and may or may not be present as for, those in `ContentHandler.startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)`.

      Parameters:
        `namespaceURI` - namespace URI
        `localName` - local name
        `qName` - qualified name
      Returns:
        element name in VOTable namespace

    - #### getVOTagName

          public java.lang.String getVOTagName(org.w3c.dom.Element el)

      Returns the VOTable tagname for an XML element as present in a DOM. The return value is a bare string which may be compared to one of the VOTable element names ignoring namespaces; for instance a return value of "TABLE" indicates that this is a VOTable TABLE element.
      Parameters:
        `el` - element
      Returns:
        element name in VOTable namespace

    - #### toString

          public java.lang.String toString()

      Returns the name of this namespacing policy.
      Overrides:
        `toString` in class `java.lang.Object`
      Returns:
        name

    - #### getInstance

          public static Namespacing getInstance()

      Returns the default Namespacing instance. The default value is determined by examining the `POLICY_PROP` system property. If not otherwise set the default is currently `LAX`.
      Returns:
        namespacing instance

    - #### setInstance

          public void setInstance(Namespacing instance)

      Sets the default instance.
      Parameters:
        `instance` - new default instance

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