ch.maxant.rules

Class JavascriptEngine

java.lang.Object

ch.maxant.rules.Engine

ch.maxant.rules.JavascriptEngine

public class JavascriptEngine
extends Engine

A Javascript based Subclass of Engine.
ONLY TESTED WITH JAVA 8 AND NASHORN!!
Quite likely to work very differently with Java SE 6 or Java SE 7!

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	JavascriptEngine.Builder

Field Summary

Fields inherited from class ch.maxant.rules.Engine

DEFAULT_INPUT_NAME, inputName, javascriptFilesToLoad, parsedRules, poolSize, throwExceptionIfCompilationFails, uniqueOutcomes

Constructor Summary

Constructors

Constructor and Description
JavascriptEngine(Collection<Rule> rules, boolean throwExceptionIfCompilationFails, String... javascriptFilesToLoad) Creates the engine with a pool size of .
JavascriptEngine(Collection<Rule> rules, String inputName, boolean throwExceptionIfCompilationFails, Integer poolSize, boolean preloadPool, String... javascriptFilesToLoad) See {@link #JavascriptEngine(Collection, boolean, String...)

Method Summary

Modifier and Type	Method and Description
protected void	compile()
<Input> List<Rule>	getMatchingRules(String nameSpacePattern, Input input)
protected org.apache.commons.pool2.impl.GenericObjectPoolConfig	getPoolConfig() Subclasses may override this.
int[]	getPoolSize()

Methods inherited from class ch.maxant.rules.Engine

executeAllActions, executeAllActions, executeBestAction, executeBestAction, getBestOutcome, getBestOutcome, getMatchingRules, init

Methods inherited from class java.lang.Object

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

Constructor Detail

JavascriptEngine

public JavascriptEngine(Collection<Rule> rules,
                        boolean throwExceptionIfCompilationFails,
                        String... javascriptFilesToLoad)
                 throws DuplicateNameException,
                        CompileException,
                        ParseException

Creates the engine with a pool size of . The pool is not preloaded.

Parameters:

rules - The rules which define the system. Please note that rules may access the input using bean notation (e.g. "input.people[0].name") OR Java notation (e.g. "input.getPeople().get(0).getName()").

throwExceptionIfCompilationFails - if true, and a rule cannot be compiled, then a CompileException will be thrown.

javascriptFilesToLoad - optional list of scripts to load - either script names found on classpath, or actual scripts.

Throws:

DuplicateNameException - thrown if any rules have the same name within a namespace

CompileException - thrown if throwExceptionIfCompilationFails is true, and a rule fails to compile, because its expression is invalid

ParseException - Thrown if a subrule which is referenced in a rule cannot be resolved.

JavascriptEngine

public JavascriptEngine(Collection<Rule> rules,
                        String inputName,
                        boolean throwExceptionIfCompilationFails,
                        Integer poolSize,
                        boolean preloadPool,
                        String... javascriptFilesToLoad)
                 throws DuplicateNameException,
                        CompileException,
                        ParseException

See {@link #JavascriptEngine(Collection, boolean, String...)

Parameters:

inputName - the name of the input in scripts, normally "input", but you can specify your own name here.

jsonifyInput - if true, then the input can be accessed using bean notation, such as "input.passengers[0].name" rather than using Java notation such as "input.getPassengers().get(0).getName()".

poolSize - the maximum size of the pool. You can override more of the pool configuration by overriding the method getPoolConfig().

preloadPool - if true, then before the constructor returns, it fills the pool.

Throws:

DuplicateNameException

CompileException

ParseException

Method Detail

getPoolSize

public int[] getPoolSize()

Returns:

[numActive, numIdle]

getPoolConfig

protected org.apache.commons.pool2.impl.GenericObjectPoolConfig getPoolConfig()

Subclasses may override this. But the default will create a config which sets up the pool using the size passed into the constructor, otherwise accessible as poolSize.

compile

protected void compile()
                throws CompileException

Overrides:

compile in class Engine

Throws:

CompileException

getMatchingRules

public <Input> List<Rule> getMatchingRules(String nameSpacePattern,
                                           Input input)

Overrides:

getMatchingRules in class Engine

Type Parameters:

Input - the type of input

Parameters:

nameSpacePattern - optional. if not null, then only rules with matching namespaces are evaluated.

input - the Object containing all inputs to the expression language rule.

Returns:

an ordered list of Rules which evaluated to "true", sorted by Rule.getPriority(), with the highest priority rules first in the list.