flowable表单引擎

flowable表单引擎作为一个独立的模块，也包括表单定义，部署等过程。

1. API及与流程引擎的结合

如下图所示，表单引擎也有一个独立的配置文件，配置类，配置引擎及三个Service.

在实际使用中我们也是将其配置嵌入到流程引擎的配置中，配置形式如下(省略了非相关配置)：

    <bean id="processEngineConfiguration"
          class="org.flowable.spring.SpringProcessEngineConfiguration">
        <property name="dataSource" ref="dataSource"/>
        <property name="transactionManager" ref="transactionManager"/>
        <property name="databaseSchemaUpdate" value="true"/>
        <property name="asyncExecutorActivate" value="false" />
        <property name="configurators">
            <list>
                <bean class="org.flowable.form.engine.configurator.FormEngineConfigurator">
                    <property name="formEngineConfiguration">
                        <bean class="org.flowable.form.engine.impl.cfg.StandaloneFormEngineConfiguration">
                            <property name="dataSource" ref="dataSource"/>
                            <property name="databaseSchemaUpdate" value="true"/>
                        </bean>
                    </property>
                </bean>
            </list>
        </property>
    </bean>


    <bean id="formRepositoryService" factory-bean="processEngine" factory-method="getFormEngineRepositoryService" />

在应用重启时数据库中会增加act_fo_为前缀的六张数据库表格：
act_fo_databasechangelog: Liquibase用来跟踪数据库变量的
act_fo_databasechangeloglock: Liquibase用来保证同一时刻只有一个Liquibase实例在运行
act_fo_form_definition:存储表单定义的信息
act_fo_form_instance:存储用户填充后表单实例信息
act_fo_form_deployment:存储表单部署元数据
act_fo_form_resource:存储表单定义的资源

2. 表单的定义

表单定义文件是以.form为后缀， 内容格式为Json格式。如下示例所示。

{
    "key": "form1",
    "name": "My first form",
    "fields": [
        {
            "id": "input1",
            "name": "Input1",
            "type": "text",
            "required": false,
            "placeholder": "empty"
        }
    ],
    "outcomes": [
        {
            "id": "null",
            "name": "Accept"
        },
        {
            "id": "null",
            "name": "Reject"
        }
    ]
}

该文件的key属性是其唯一性标识，表单引擎可以通过该key获取到它， 同时数据库对相同key会维护不同的版本。第二部分是表单字段数组，第三部分是表单结果。每一个表单字段都有id,name和type属性。id属性在同一个表单定义文件中必须唯一，当用户赋值时它会作为变量的名称，在上例中，也就是会创建名称为input1的变量，值由用户填入。同时表单结果也会以form_<form-identifier>_outcome获取得到，对于上例，用户选择的结果会赋值给form_form1_outcome， 我们可以通过${form_form1_outcome == "Accept"}表达式来验证表单结果是否为Accept。
表单字段的type属性支持text, multi-line-text,integer,boolean,date等多种类型。

3. 表单的使用

首先在src/main/resources文件夹下创建test.form表单定义文件，内容如下：

{
"key": "form1",
"name": "请假流程",
"fields": [
            {
            "id": "startTime",
            "name": "开始时间",
            "type": "date",
            "required": true,
            "placeholder": "empty"

            },
            {
            "id": "endTime",
            "name": "结束时间",
            "type": "date",
            "required": true,
            "placeholder": "empty"
            },
            {
            "id": "reason",
            "name": "请假原因",
            "type": "text",
            "required": true,
            "placeholder": "empty"
            }
    ]
}

然后创建test-form.bpmn20.xml流程定义文件：

<?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:xsd="http://www.w3.org/2001/XMLSchema"
             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"
             xmlns:flowable="http://flowable.org/bpmn"
             typeLanguage="http://www.w3.org/2001/XMLSchema"
             expressionLanguage="http://www.w3.org/1999/XPath"
             targetNamespace="http://www.flowable.org/processdef">

    <process id="holidayRequest" name="Holiday Request" isExecutable="true">

        <startEvent id="startEvent" flowable:formKey="form1"/>
        <sequenceFlow sourceRef="startEvent" targetRef="approveTask"/>

        <userTask id="approveTask" name="Approve or reject request" flowable:formKey="form1" flowable:candidateGroups="managers"/>
        <sequenceFlow sourceRef="approveTask" targetRef="holidayApprovedTask"/>

        <userTask id="holidayApprovedTask" name="Holiday approved" flowable:formKey="form1" flowable:assignee="employee"/>
        <sequenceFlow sourceRef="holidayApprovedTask" targetRef="approveEnd"/>

        <endEvent id="approveEnd"/>

    </process>

</definitions>

上面的开始事件和两个用户任务都带有flowable:formKey属性。
然后就可以创建测试类了，注意用runtimeService.startProcessInstanceWithForm方法启动带表单的流程，runtimeService.getStartFormModel查询流程启动时的表单信息; taskService.completeTaskWithForm填充表单完成任务，taskService.getTaskFormModel查询任务表单信息。具体测试类代码如下：

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class FormTest {
    @Autowired
    private RepositoryService repositoryService;

    @Autowired
    private RuntimeService runtimeService;

    @Autowired
    private FormRepositoryService formRepositoryService;

    @Autowired
    private TaskService taskService;

    @Autowired
    private HistoryService historyService;

    /**
     * 流程以及表单的部署
     */
    @Test
    public void deployTest(){
        Deployment deployment = repositoryService.createDeployment()
                .name("表单流程")
                .addClasspathResource("flowable/test-form.bpmn20.xml")
                .deploy();

        ProcessDefinition processDefinition = repositoryService.createProcessDefinitionQuery().
                deploymentId(deployment.getId())
                .singleResult();
        String processDefinitionId = processDefinition.getId();
        FormDeployment formDeployment = formRepositoryService.createDeployment()
                .name("definition-one")
                .addClasspathResource("flowable/test.form")
                .parentDeploymentId(deployment.getId())
                .deploy();
        FormDefinition formDefinition = formRepositoryService.createFormDefinitionQuery().deploymentId(formDeployment.getId()).singleResult();
        String formDefinitionId = formDefinition.getId();



        //启动实例并且设置表单的值
        String outcome = "shareniu";
        Map<String, Object> formProperties;
        formProperties = new HashMap<>();
        formProperties.put("reason", "家里有事");
        formProperties.put("startTime", Dates.format(new Date(), Dates.Pattern.DATE));
        formProperties.put("endTime", Dates.format(new Date(), Dates.Pattern.DATE));
        String processInstanceName = "shareniu";
        runtimeService.startProcessInstanceWithForm(processDefinitionId, outcome, formProperties, processInstanceName);
        HistoricProcessInstanceEntity historicProcessInstanceEntity = (HistoricProcessInstanceEntity )historyService.createHistoricProcessInstanceQuery()
                .processDefinitionId(processDefinitionId)
                .singleResult();
        String processInstanceId = historicProcessInstanceEntity.getProcessInstanceId();



        //查询表单信息
        FormModel fm = runtimeService.getStartFormModel(processDefinitionId, processInstanceId);
        System.out.println(fm.getId());
        System.out.println(fm.getKey());
        System.out.println(fm.getName());
        System.out.println(fm.getOutcomeVariableName());
        System.err.println(fm.getVersion());
        List<FormField> fields = fm.getFields();
        for (FormField ff : fields) {
            System.out.println("######################");
            System.out.println(ff.getId());
            System.out.println(ff.getName());
            System.out.println(ff.getType());
            System.out.println(ff.getPlaceholder());
            System.out.println(ff.getValue());
            System.out.println("######################");

        }


        //查询个人任务并填写表单
        Map<String, Object> formProperties2 = new HashMap<>();
        formProperties2.put("reason", "家里有事2222");
        formProperties2.put("startTime", Dates.format(new Date(), Dates.Pattern.DATE));
        formProperties2.put("endTime", Dates.format(new Date(), Dates.Pattern.DATE));
        formProperties2.put("days", "3");
        Task task = taskService.createTaskQuery().processInstanceId(processInstanceId).singleResult();
        String taskId = task.getId();
        String outcome2="牛哥";
        taskService.completeTaskWithForm(taskId, formDefinitionId, outcome2, formProperties2);

        //获取个人任务表单
        FormModel taskFM = taskService.getTaskFormModel(taskId);
    }

}