1 Excel Decision table

1.1 很棒的示意图，来自https://blog.csdn.net/justlpf/article/details/128109731

1.2 参考URL
1.2.1 https://blog.csdn.net/justlpf/article/details/128109731
1.3 多sheet 模式

• 默认是用第一个sheet
• 如果要支持多sheet，需要创建一个同名的.properties文件
  • sheets=Sheet1,Sheet2

1.4 sheet内主要内容
1.4.1 一个RuleSet ：注意RuleSet里面的定义都是对package有影响，不仅仅是excel文件
默认package 名就是Ruleset 名称

• 具体实现代码-final Package ruleset = new Package( (showPackage) ? rulesetName : null );

属性

• RuleSet
  The package name for the generated DRL file. Optional, the default is rule_table.
• Sequential
  true or false. If true, then salience is used to ensure that rules fire from the top down.
• SequentialMaxPriority
  Optional, at most once. In sequential mode, this option is used to set the start value of the salience. If omitted, the default value is 65535.
• SequentialMinPriorit
  Optional, at most once. In sequential mode, this option is used to check if this minimum salience value is not violated. If omitted, the default value is 0.
• EscapeQuotes
• NumericDisabled
  If true, then a String representation is used for DRL instead of a double value from a Numeric cell. It would also skip additional numeric processing for the double value.
• IgnoreNumericFormat
  If true, then the format for numeric values is ignored
• Import
  可以多行
• Variables
  可以多行
• Functions
  可以多行
• Queries
  可以多行
• Declare
  可以多行
• Unit 实验性，不用
• Dialect
  java or mvel. The dialect used in the actions of the decision table.

1.4.2 一个或者多个RuleTable

• 以空行分割多个RuleTable
• 无论CONDITION/RULE，值为空代表忽略
• metadata
  • Code snippet and interpolated values for constructing a metadata entry for the rule.
  • 没有google到例子

Properties 和rule 属性差不多，但注意salience 被priority代替

• PRIORITY An integer defining the salience value of the rule
• DATE-EFFECTIVE
  Example: DATE-EFFECTIVE “4-Sep-2018”
• DATE-EXPIRES
• NO-LOOP
• AGENDA-GROUP
• ACTIVATION-GROUP
• DURATION
• TIMER
• CALENDAR
• AUTO-FOCUS
• LOCK-ON-ACTIVE
• RULEFLOW-GROUP

1.5 excel 转换为drl文件的核心类是public class DefaultRuleSheetListener
1.5.1 核心函数buildRuleSet()

2 template

2.1 用途

• 使用外部存储的变量列表：如数据库、excel 生成drl文件
• 默认提供了从excel ，对象、list导入数据模式

2.2 相关生成drl的compiler

• ExternalSpreadsheetCompiler
• DataProviderCompiler
  可以以DataProviderCompiler为父类，自行定义开发新的compiler
• ObjectDataCompiler
  • extends DataProviderCompiler
  • 当对象有null值被引用的时候，DefaultGenerator如下代码可能返回空condition

String drl = String.valueOf( TemplateRuntime.execute( template,vars,factory,registry ) );