com.google.appengine.api.search.dev
Class Expression

java.lang.Object
  com.google.appengine.api.search.dev.Expression

Direct Known Subclasses:

ExpressionBuilder.EmptyExpression, ExpressionBuilder.IntValueExpression, FieldExpression, NumericDefaultExpression, SnippetExpression

public abstract class Expression
extends java.lang.Object

Abstract base class for all expression evaluators.

Nested Class Summary

static interface

Expression.Sorter Sort class for potential multi dimensional sorting of the expression.

Constructor Summary

Expression()

Method Summary

abstract FieldValue	eval(Document doc) Evaluate the expression to field value proto for the specified document.
abstract java.util.List<Expression.Sorter>	getSorters(int sign, double defaultValueNumeric, java.lang.String defaultValueText) Get list of sort classes for the expression.
static FieldValue	makeValue(ContentType type, java.lang.String stringValue) Helper function to make field value proto from specified content.

Methods inherited from class java.lang.Object

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

Constructor Detail

Expression

public Expression()

Method Detail

eval

public abstract FieldValue eval(Document doc)
                         throws EvaluationException

Evaluate the expression to field value proto for the specified document.

Throws:

EvaluationException

makeValue

public static final FieldValue makeValue(ContentType type,
                                         java.lang.String stringValue)

Helper function to make field value proto from specified content.

getSorters

public abstract java.util.List<Expression.Sorter> getSorters(int sign,
                                                             double defaultValueNumeric,
                                                             java.lang.String defaultValueText)

Get list of sort classes for the expression. Usually it contains just one element, but for field expressions it can potentially return 2 sorters when both numeric and text fields exist with a field name.