flowable表單引擎作為一個(gè)獨(dú)立的模塊，也包括表單定義，部署等過程。

1. API及與流程引擎的結(jié)合

如下圖所示，表單引擎也有一個(gè)獨(dú)立的配置文件，配置類，配置引擎及三個(gè)Service.

在實(shí)際使用中我們也是將其配置嵌入到流程引擎的配置中，配置形式如下(省略了非相關(guān)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" />

在應(yīng)用重啟時(shí)數(shù)據(jù)庫中會(huì)增加act_fo_為前綴的六張數(shù)據(jù)庫表格：
act_fo_databasechangelog: Liquibase用來跟蹤數(shù)據(jù)庫變量的
act_fo_databasechangeloglock: Liquibase用來保證同一時(shí)刻只有一個(gè)Liquibase實(shí)例在運(yùn)行
act_fo_form_definition:存儲表單定義的信息
act_fo_form_instance:存儲用戶填充后表單實(shí)例信息
act_fo_form_deployment:存儲表單部署元數(shù)據(jù)
act_fo_form_resource:存儲表單定義的資源

2. 表單的定義

表單定義文件是以.form為后綴， 內(nèi)容格式為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"
        }
    ]
}

該文件的key屬性是其唯一性標(biāo)識，表單引擎可以通過該key獲取到它， 同時(shí)數(shù)據(jù)庫對相同key會(huì)維護(hù)不同的版本。第二部分是表單字段數(shù)組，第三部分是表單結(jié)果。每一個(gè)表單字段都有id,name和type屬性。id屬性在同一個(gè)表單定義文件中必須唯一，當(dāng)用戶賦值時(shí)它會(huì)作為變量的名稱，在上例中，也就是會(huì)創(chuàng)建名稱為input1的變量，值由用戶填入。同時(shí)表單結(jié)果也會(huì)以form_<form-identifier>_outcome獲取得到，對于上例，用戶選擇的結(jié)果會(huì)賦值給form_form1_outcome， 我們可以通過${form_form1_outcome == "Accept"}表達(dá)式來驗(yàn)證表單結(jié)果是否為Accept。
表單字段的type屬性支持text, multi-line-text,integer,boolean,date等多種類型。

3. 表單的使用

首先在src/main/resources文件夾下創(chuàng)建test.form表單定義文件，內(nèi)容如下：

{
"key": "form1",
"name": "請假流程",
"fields": [
            {
            "id": "startTime",
            "name": "開始時(shí)間",
            "type": "date",
            "required": true,
            "placeholder": "empty"

            },
            {
            "id": "endTime",
            "name": "結(jié)束時(shí)間",
            "type": "date",
            "required": true,
            "placeholder": "empty"
            },
            {
            "id": "reason",
            "name": "請假原因",
            "type": "text",
            "required": true,
            "placeholder": "empty"
            }
    ]
}

然后創(chuàng)建test-form.bpmn20.xml流程定義文件：

<?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>

上面的開始事件和兩個(gè)用戶任務(wù)都帶有flowable:formKey屬性。
然后就可以創(chuàng)建測試類了，注意用runtimeService.startProcessInstanceWithForm方法啟動(dòng)帶表單的流程，runtimeService.getStartFormModel查詢流程啟動(dòng)時(shí)的表單信息; taskService.completeTaskWithForm填充表單完成任務(wù)，taskService.getTaskFormModel查詢?nèi)蝿?wù)表單信息。具體測試類代碼如下：

@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;

    /**
     * 流程以及表單的部署
     */
    @Test
    public void deployTest(){
        Deployment deployment = repositoryService.createDeployment()
                .name("表單流程")
                .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();



        //啟動(dòng)實(shí)例并且設(shè)置表單的值
        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();



        //查詢表單信息
        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("######################");

        }


        //查詢個(gè)人任務(wù)并填寫表單
        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);

        //獲取個(gè)人任務(wù)表單
        FormModel taskFM = taskService.getTaskFormModel(taskId);
    }

}