[C#][Bot Framework] 動態產生FormFlow 選項

Dynamic choice field

假設我們現在有個三明治點餐機器人

而點餐的流程是：要求使用者輸入Sandwich種類，大小( Length)，以及  Cheese  種類

那底下的Sample code就能滿足我們目前的需求

[ Serializable ] public  class  SandwichOrder {                  public  SandwichOptions ? Sandwich;         [ Prompt ( "What size do you want? {||}" )]         public  LengthOptions ? Length;                    [ Optional ]         public  CheeseOptions ? Cheese;                    public  static  IForm < SandwichOrder > BuildForm()         {             return  new  FormBuilder < SandwichOrder >()                         .Message( "Welcome to the simple sandwich order bot!" )                                               .Build();         } }; public  enum  SandwichOptions {  BLT, BlackForestHam, BuffaloChicken }; public  enum  LengthOptions  { SixInch, FootLong }; public  enum  CheeseOptions  { American, MontereyCheddar, Pepperjack };

但如果今天遊戲規則變成：

不同的三明治就有不同的附餐可以選擇

如：

三明治種類	副餐選項
BLT	cookie, coke
BlackForestHam	cookie, salard
BuffaloChicken	coke, salard

此時程式碼就需要改成根據三明治的種類動態產生附餐的選擇

那我們原先定義的form class裡面就需多宣告一個property 來表達副餐如：

[ Optional ]         [ Template ( TemplateUsage .NoPreference,  "None" )]         public  string  Specials;

原來產生Form的程式碼

public  static  IForm < SandwichOrder > BuildForm()         {             return  new  FormBuilder < SandwichOrder >()                         .Message( "Welcome to the simple sandwich order bot!" )                                               .Build();         }

需改成再透過FormFlow.FormBuilder手動呼叫.Field(IField< T >field) 來產生客製化的field如下

public static IForm < SandwichOrder > BuildForm()           {             return new FormBuilder < SandwichOrder >()                   .Message( "Welcome to the simple sandwich order bot!" )                                 .Field( nameof (Sandwich))                 .Field( nameof (Length))                 .Field( nameof (Cheese))                 .Field( new FieldReflector < SandwichOrder >( nameof (Specials))                      .SetType( null )                     .SetDefine( async  (state, field) =>                     {                         var  dic = GetSpecialFree(state.Sandwich);                         foreach  ( KeyValuePair < string ,  string []> item  in  dic)                         {                             field                                 .AddDescription(item.Key, item.Value[0])                                 .AddTerms(item.Key, item.Value);                         }                         return true ;                      }))                 .Build();         }

這裡我們使用Advanced.FieldReflector< T >.FieldReflector(string name, bool ignoreAnnotations = false)來替副餐簡單產生一個IField的實體

再加以呼叫Advanced.Field< T >.SetDefine(DefineAsyncDelegate< T > definition )定義副餐field的內容

　

其中：GetSpecialFree 可以改成去Db裡讀資料, 取出和三明治對應的副餐選擇,

(以下的實作方式是為了簡化說明)

public  static  Dictionary < string ,  string []> GetSpecialFree( SandwichOptions ? sandwichOptions)         {             Dictionary < string ,  string []> dic =  new  Dictionary < string ,  string []>();             switch  (sandwichOptions)             {                 case  SandwichOptions .BLT:                     dic.Add( "cookie" ,  new  string [] {  "Free cookie" ,  "cookie"  });                     dic.Add( "drink" ,  new  string [] {  "Free drink" ,  "drink"  });                     break ;                  case  SandwichOptions .BlackForestHam:                     dic.Add( "cookie" ,  new  string [] {  "Free cookie" ,  "cookie"  });                     dic.Add( "salard" ,  new  string [] {  "Free salard" ,  "salard"  });                     break ;                 case  SandwichOptions .BuffaloChicken:                     dic.Add( "drink" ,  new  string [] {  "Free drink" ,  "drink"  });                     dic.Add( "salard" ,  new  string [] {  "Free salard" ,  "salard"  });                     break ;             }             return  dic;         }

結果：

補充Ｉ：

若想在某特定條件下才觸發這個選擇

我們可以透過呼叫Advanced.Field< T >.SetActive(ActiveDelegate< T > condition)來達成

.SetActive((state) => state.Length == LengthOptions .FootLong )

表示當　state.Length == LengthOptions .FootLong 　這個條件成立時才會產生這個field

補充ＩＩ：

以上的範例也可以改成呼叫. AddRemainingFields()

把定義在form class裡的成員給帶進來

public static IForm < SandwichOrder > BuildForm()         {             return new FormBuilder < SandwichOrder >()                 .Message( "Welcome to the simple sandwich order bot!" )                 . AddRemainingFields()                 .Field( new FieldReflector < SandwichOrder >( nameof (Specials))                     .SetType( null )                     .SetDefine( async (state, field) =>                     {                         var dic = GetSpecialFree(state.Sandwich);                         foreach ( KeyValuePair < string , string []> item in dic)                         {                             field                                 .AddDescription(item.Key, item.Value[0])                                 .AddTerms(item.Key, item.Value);                         }                         return true ;                     }))                 .Build();         }

完整的Sample Code

https://github.com/andy51002000/DynamicChoiceFieldBot