org.sqlproc.engine.plugin
Interface IsTruePlugin

All Known Implementing Classes:

DefaultSqlPlugins

public interface IsTruePlugin

The SQL Processor plugin devoted to evaluate the boolean value of the logical expression.

A boolean expression is an expression of the input values with the following operands between them:

• ! an exclamation mark - for a logical negation
• ( and ) left and right round brackets – for a logical grouping
• && two ampersands – for a logical conjunction
• || two vertical bars – for a logical disjunction

The standard evaluation is the next one:

A logical value of an input value (dynamic or static) depends on the Java type of the related attribute. If the value is null, it is evaluated as false. Otherwise it is evaluated as true in the following cases

• Boolean or boolean – a logical value of the related attribute
• any type of Number – if the related attribute value is a positive one
• String - if the related attribute length is greater than zero. A special case is a token false, which is evaluated as false.
• an enumeration based attribute is treated in a special way, please see the advanced tutorial

Author:

Vladimir Hudec

Method Summary

boolean

isTrue(Object obj, SqlMetaType sqlMetaType, String sqlMetaTypeExt) Used for the evaluation of the logical expression in the conditional META SQL fragments.

Method Detail

isTrue

boolean isTrue(Object obj,
               SqlMetaType sqlMetaType,
               String sqlMetaTypeExt)

Used for the evaluation of the logical expression in the conditional META SQL fragments.

Parameters:

obj - the input value

sqlMetaType - the internal type (= META type) devoted for the special processing of the input values

sqlMetaTypeExt - the META type extension (=the internal type supplement value) devoted to extend the special processing of the input values

Returns:

the boolean value of the logical expression