30分钟用Restful ABAP Programming模型开发一个支持增删改查的Fiori应用

2019 年 10 月 6 日
筆記

本文链接：https://jerry.blog.csdn.net/article/details/101197460

2016年时，Jerry曾经写过一系列关于SAP Fiori Smart Template(现在更名为Fiori Elements了)的博客，介绍了所谓的MDD开发方法论 – Metadata Driven Development，即通过开发维护了对应annotation(注解)的CDS view，结合SAP WebIDE，能够花费最少的编程代价，就能够在短时间内获得一个支持增删改查的Fiori应用。

这个系列的博客集可以在Jerry这篇公众号文章里获得：Jerry的通过CDS view + Smart Template 开发Fiori应用的blog合集。

三年的时间过去了，ABAP在不断向前进化，如今我们有了新的编程模型：Restful ABAP Programming模型，简称为RAP模型。该模型定义了一套架构体系，应用开发人员能够凭借其来高效地进行应用的端到端开发，这种应用具有与生俱来的Restful特质，能充分利用HANA平台的强大计算能力，支持云环境和Fiori UX。

RAP模型的三大支柱：

Business Service
Core Data Service
Behavior Definition

下面请跟着Jerry一起，通过一个实际的例子，了解一下这种全新的通过Restful ABAP Programming模型进行Fiori应用开发的步骤吧。

Jerry还是沿用传统ABAP On-Premises编程培训教材里使用过的经典的SFLIGHT模型来作为底层数据库存储。

(1）首先创建一个数据库表ZTRAVEL_JERRY：(如果想复制这段源代码，请点击文末的“阅读原文”获得)

@EndUserText.label : 'Database table for travel data XXX'  @AbapCatalog.enhancementCategory : #NOT_EXTENSIBLE  @AbapCatalog.tableCategory : #TRANSPARENT  @AbapCatalog.deliveryClass : #A  @AbapCatalog.dataMaintenance : #LIMITED  define table ztravel_jerry {    key client      : abap.clnt not null;    key travel_id   : /dmo/travel_id not null;    agency_id       : /dmo/agency_id;    customer_id     : /dmo/customer_id;    begin_date      : /dmo/begin_date;    end_date        : /dmo/end_date;    @Semantics.amount.currencyCode : 'ztravel_jerry.currency_code'    booking_fee     : /dmo/booking_fee;    @Semantics.amount.currencyCode : 'ztravel_jerry.currency_code'    total_price     : /dmo/total_price;    currency_code   : /dmo/currency_code;    description     : /dmo/description;    created_by      : syuname;    created_at      : timestampl;    last_changed_by : syuname;    last_changed_at : timestampl;    }

因为我们在ABAP Development Tools里无法用事务码SE16手动往这张表里插入数据，所以我创建一个ABAP类，用ABAP代码往这个表里插入三条数据。

按F9执行这个ABAP类，然后看到三条数据成功插入了：

(2) 我们最终的目的是创建一个支持对这张表进行增删改查的Fiori应用，而Restful ABAP Programming模型的三大支柱之一为Core Data Service，因此我们首先得有基于数据库表ZTRAVEL_JERRY的CDS view.

所以我首先创建一个CDS view：

@AbapCatalog.sqlViewName: 'ZVI_TRAVEL'  @AbapCatalog.compiler.compareFilter: true  @AbapCatalog.preserveKey: true  @AccessControl.authorizationCheck: #CHECK  @EndUserText.label: 'Travel data - XXX'  define root view ZI_TRAVEL_JERRY     as select from ztravel_jerry as Travel     /* Associations */   association [0..1] to /DMO/I_Agency   as _Agency   on $projection.agency_id = _Agency.AgencyID   association [0..1] to /DMO/I_Customer as _Customer on $projection.customer_id = _Customer.CustomerID   association [0..1] to I_Currency      as _Currency on $projection.currency_code = _Currency.Currency   {    key travel_id,       agency_id,       customer_id,       begin_date,       end_date,       @Semantics.amount.currencyCode: 'currency_code'       booking_fee,       @Semantics.amount.currencyCode: 'currency_code'       total_price,       @Semantics.currencyCode: true       currency_code,       description,    /*-- Admin data --*/       @Semantics.user.createdBy: true       created_by,       @Semantics.systemDateTime.createdAt: true       created_at,       @Semantics.user.lastChangedBy: true       last_changed_by,       @Semantics.systemDateTime.lastChangedAt: true       last_changed_at,         /* Public associations */       _Agency,       _Customer,       _Currency  }

然后创建一个projection view，将该view的字段有选择性地暴露出来。

@EndUserText.label: 'Travel projection view - Processor'  @AccessControl.authorizationCheck: #NOT_REQUIRED    @UI: {   headerInfo: { typeName: 'Travel', typeNamePlural: 'Travels', title: { type: #STANDARD, value: 'TravelID' } } }    @Search.searchable: true    define root view entity ZC_TRAVEL_JERRY as projection on ZI_TRAVEL_JERRY {   @UI.facet: [ { id:              'Travel',                  purpose:         #STANDARD,                  type:            #IDENTIFICATION_REFERENCE,                  label:           'Travel',                  position:        10 } ]     @UI: {       lineItem:       [ { position: 10, importance: #HIGH } ],       identification: [ { position: 10, label: 'Travel ID [1,...,99999999]' } ] }   @Search.defaultSearchElement: true   key travel_id          as TravelID,     @UI: {       lineItem:       [ { position: 20, importance: #HIGH } ],       identification: [ { position: 20 } ],       selectionField: [ { position: 20 } ] }   @Consumption.valueHelpDefinition: [{ entity : {name: '/DMO/I_Agency', element: 'AgencyID'  } }]     @ObjectModel.text.element: ['AgencyName'] ----meaning?   @Search.defaultSearchElement: true   agency_id          as AgencyID, _Agency.Name       as AgencyName,     @UI: {       lineItem:       [ { position: 30, importance: #HIGH } ],       identification: [ { position: 30 } ],       selectionField: [ { position: 30 } ] }   @Consumption.valueHelpDefinition: [{ entity : {name: '/DMO/I_Customer', element: 'CustomerID'  } }]     @ObjectModel.text.element: ['CustomerName']   @Search.defaultSearchElement: true   customer_id        as CustomerID,     @UI.hidden: true   _Customer.LastName as CustomerName,     @UI: {       lineItem:       [ { position: 40, importance: #MEDIUM } ],       identification: [ { position: 40 } ] }   begin_date         as BeginDate,     @UI: {       lineItem:       [ { position: 41, importance: #MEDIUM } ],       identification: [ { position: 41 } ] }   end_date           as EndDate,     @UI: {       lineItem:       [ { position: 50, importance: #MEDIUM } ],       identification: [ { position: 50, label: 'Total Price' } ] }   @Semantics.amount.currencyCode: 'CurrencyCode'   total_price        as TotalPrice,     @Consumption.valueHelpDefinition: [{entity: {name: 'I_Currency', element: 'Currency' }}]   currency_code      as CurrencyCode,     @UI.identification: [ { position: 60, label: 'Remarks' } ]   description as Description,     @UI.hidden: true   last_changed_at    as LastChangedAt     }

大家可以注意到，这个projection view里包含了很多@UI注解，作用和Fiori Elements一样，作为元数据，告诉对应的渲染框架，运行时这些字段应该以什么样的方式渲染在Fiori UI上。

(3) 现在三大支柱之一的Core Data Service已经就位了，接下来我们基于前一步得到的projection view创建Business Service. 选中projection view，右键选择New Service Definition：

这个服务定义的第一条记录，就是通过ABAP expose关键字把projection view ZC_TRAVEL_JERRY暴露出来，模型名称为TravelProcessor：

@EndUserText.label: 'Service Defintion for ZC_Travel_JERRY'  define service ZUI_C_TRAVEL_JERRY {    expose ZC_TRAVEL_JERRY as TravelProcessor;    expose /DMO/I_Customer as Passenger;    expose /DMO/I_Agency as TravelAgency;    expose /DMO/I_Airport as Airport;    expose I_Currency as Currency;    expose I_Country as Country;  }

然后基于这个Service Definition创建一个Service Binding，可以简单把Service Binding理解成Service Definition的一个实例：

Service Binding创建完毕后，点击Activate激活：

之前Service Definition里用expose关键字暴露并指定成的模型TravelProcessor此时就可见了，双击：

双击后会自动打开一个链接，一个Fiori应用就呈现在我们眼前了。我们没有进行一行的JavaScript web编程，就得到了一个专业的支持高级搜索的Fiori应用，能查看底层数据库表ZTRAVEL_JERRY的内容。

(4) 至此我们已经了解了Restful ABAP Programming模型的前两大支柱，还剩下Behavior Definition. 既然RAP的口号是打造具有Restful特性的应用，但到目前为止我们还没有感受到RAP对Restful的支持，这有待Behavior Definition来完成。

选中之前创建的CDS view，创建一个新的Behavior Definition：