## com.icl.saxon.sort
Class SortKeyDefinition

    java.lang.Object
      com.icl.saxon.sort.SortKeyDefinition

public class SortKeyDefinition
extends java.lang.Object

A SortKeyDefinition defines one component of a sort key.
Note that most attributes defining the sort key can be attribute value templates, and can therefore vary from one invocation to another. We hold them as expressions, but optimise for the case where the attributes are all fixed strings: in this case we can use the same Comparer object each time.

Constructor Summary
`SortKeyDefinition()`

Method Summary
`void` `bindComparer()` If possible, use the same comparer every time
`Expression` `getCaseOrder()`
`Comparer` `getComparer(Context context)` Get a Comparer which can be used to compare two values according to this sort key.
`Expression` `getDataType()`
`Expression` `getLanguage()`
`Expression` `getOrder()`
`Expression` `getSortKey()`
`void` `setCaseOrder(Expression exp)` Set the case order.
`void` `setDataType(Expression exp)` Set the data type.
`void` `setLanguage(Expression exp)` Set the language.
`void` `setOrder(Expression exp)` Set the order.
`void` `setSortKey(Expression exp)` Set the expression used as the sort key
`void` `setStaticContext(StaticContext sc)` Set the static context.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### SortKeyDefinition

    public SortKeyDefinition()

Method Detail

### setSortKey

    public void setSortKey(Expression exp)

  Set the expression used as the sort key

### setOrder

    public void setOrder(Expression exp)

  Set the order. This is supplied as an expression which must evaluate to "ascending" or "descending". If the order is fixed, supply e.g. new StringValue("ascending"). Default is "ascending".

### setDataType

    public void setDataType(Expression exp)

  Set the data type. This is supplied as an expression which must evaluate to "text", "number", or a QName. If the data type is fixed, supply e.g. new StringValue("text"). Default is "text".

### setCaseOrder

    public void setCaseOrder(Expression exp)

  Set the case order. This is supplied as an expression which must evaluate to "upper-first" or "lower-first" or "#default". If the order is fixed, supply e.g. new StringValue("lower-first"). Default is "#default".

### setLanguage

    public void setLanguage(Expression exp)

  Set the language. This is supplied as an expression which evaluate to the language name. If the order is fixed, supply e.g. new StringValue("de"). Default is "en".

### setStaticContext

    public void setStaticContext(StaticContext sc)

  Set the static context. This is used only for resolving any QName supplied in the data-type property.

### getSortKey

    public Expression getSortKey()

### getOrder

    public Expression getOrder()

### getDataType

    public Expression getDataType()

### getCaseOrder

    public Expression getCaseOrder()

### getLanguage

    public Expression getLanguage()

### bindComparer

    public void bindComparer()
                      throws XPathException

  If possible, use the same comparer every time

  Throws:
    `XPathException`

### getComparer

    public Comparer getComparer(Context context)
                         throws XPathException

  Get a Comparer which can be used to compare two values according to this sort key.

  Throws:
    `XPathException`