<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:activiti="http://activiti.org/bpmn"
    xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC"
    xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema"
    expressionLanguage="http://www.w3.org/1999/XPath"
    targetNamespace="activiti-report">

    <process  name="Process Instance Overview" isExecutable="true">

        <startEvent  name="Start" />
        <sequenceFlow  sourceRef="startevent1" targetRef="generateDataset" />

        <scriptTask  name="Execute script" scriptFormat="JavaScript" activiti:autoStoreVariables="false">
          <script><![CDATA[

               importPackage(java.sql);
               importPackage(java.lang);
               importPackage(org.activiti.explorer.reporting);

               var result = ReportingUtil.executeSelectSqlQuery("SELECT PD.NAME_, PD.VERSION_ , count(*) FROM ACT_HI_PROCINST PI inner join ACT_RE_PROCDEF PD on PI.PROC_DEF_ID_ = PD.ID_ group by PROC_DEF_ID_");

               var reportData = {};
               reportData.datasets = [];

               var dataset = {};
               dataset.type = "pieChart";
               dataset.description = "Process instance overview (" + new java.util.Date() + ")";
               dataset.data = {};

               while (result.next()) { // process results one row at a time
                 var name = result.getString(1);
                 var version = result.getLong(2)
                 var count = result.getLong(3);
                 dataset.data[name + " (v" + version + ")"] = count;
               }
               reportData.datasets.push(dataset);

               execution.setVariable("reportData", new java.lang.String(JSON.stringify(reportData)).getBytes("UTF-8"));
          ]]></script>
        </scriptTask>
        <sequenceFlow  sourceRef="generateDataset" targetRef="theEnd" />

        <endEvent  />

    </process>

</definitions>

• 除了流程xml顶部的标准xml,主要区别是targetNamespace设置为activiti-report, 把分类设置为与部署的流程定义一样的名称
  • 脚本的第一行是进行一些导入,避免每次使用时,都要写包名
  • 第一个有意义的代码是使用ReportingUtil读取activiti数据库.返回结果是一个JDBC 结果集
  • 查询语句下面 ,javascript创建了使用的json.json是符合上面描述的需求的
  • 最后一行脚本,首先需要把json对象转换成字符串,使用javascript函数JSON.stringify(). 字符串需要保存为二进制数组类型的变量
    • 这是一个技术问题:
      • 二进制数组的大小是无限的,但是字符串的长度有限制
      • 这就是为什么javascript字符串必须转换成一个java字符串以获得转换成二进制的功能
• 原生json功能无法使用,这里提供了一些帮助类ReportData和Dataset:

<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:activiti="http://activiti.org/bpmn"
    xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC"
    xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema"
    expressionLanguage="http://www.w3.org/1999/XPath"
    targetNamespace="activiti-report">

    <process  name="Process Instance Overview" isExecutable="true">

        <startEvent  name="Start" />
        <sequenceFlow  sourceRef="startevent1" targetRef="generateDataset" />

        <scriptTask  name="Execute script" scriptFormat="js" activiti:autoStoreVariables="false">
          <script><![CDATA[

               importPackage(java.sql);
               importPackage(java.lang);
               importPackage(org.activiti.explorer.reporting);

               var result = ReportingUtil.executeSelectSqlQuery("SELECT PD.NAME_, PD.VERSION_ , count(*) FROM ACT_HI_PROCINST PI inner join ACT_RE_PROCDEF PD on PI.PROC_DEF_ID_ = PD.ID_ group by PROC_DEF_ID_");





               var reportData = new ReportData;
               var dataset = reportData.newDataset();
               dataset.type = "pieChart";
               dataset.description = "Process instance overview (" + new java.util.Date() + ")"


               while (result.next()) { // process results one row at a time
                 var name = result.getString(1);
                 var version = result.getLong(2);
                 var count = result.getLong(3);
                 dataset.add(name + " (v" + version + ")", count);
               }

               execution.setVariable("reportData", reportData.toBytes());

          ]]></script>
        </scriptTask>
        <sequenceFlow  sourceRef="generateDataset" targetRef="theEnd" />

        <endEvent  />

    </process>

</definitions>

<startEvent  name="Start">
  <extensionElements>
    <activiti:formProperty  name="Select process definition" type="processDefinition" required="true" />
      <activiti:formProperty  name="Chart type" type="enum" required="true">
        <activiti:value  name="Pie chart" />
        <activiti:value  name="Bar chart" />
      </activiti:formProperty>
  </extensionElements>
</startEvent>

var processDefinition = execution.getVariable("processDefinition");