The changes in Change ChoiceSet to support LG (#5309) may need to be ported to maintain parity with microsoft/botbuilder-dotnet.

Fixes #

Description

Change ChoiceSet to be able to be defined with LG.

You can define ChoiceSet as

STRING   ==> opt1 | opt2 | opt3
STRING[] ==>  [ "opt1", "opt2", "opt3" ]
CHOICE[] ==> [ { ...opt1..}, {...opt2}, {...opt3...}] 

So with LG you can simply do the same:

# MyChoices_simple
- dog | cat

Or define objects in LG like this

# MyChoices_complex
  - '''
  [
    { "value": "dog", "synonyms": ["doggy","wolf"]  },
    { "value": "cat", "synonyms": ["pussycat","kitty"] }
  ]
   '''

So a full example:

# MyChoices_Prompt
- Please select

# MyChoices_UnknownPrompt
- Not a dog or cat. Please select

# MyChoices_simple
- dog | cat

ChoiceInput in a dialog

{
    "$kind": "Microsoft.ChoiceInput",
    "choices": "${MyChoices_simple()}",
    "prompt": "${MyChoices_Prompt()}",
    "unrecognizedPrompt": "${MyChoices_UnknownPrompt()}"
},

Specific Changes

• Implemented ITemplate.BindData method
• Changed ChoiceInput and ConfirmInput to use ITemplate.BindData()
• Fixed Try method to not throw when Expression.Parse() fails.

Testing

• Added unit tests for simple/complex binding for both ConfirmInput and ChoiceInput with multi-lingual fall back working.

Please review and, if necessary, port the changes.