Data Provider fails to provide data for a text field

Issue

• I am trying to fill a text field using the DDMRestDataProvider and the Autofill Rule. I was inspired by the following article:

  https://learn.liferay.com/w/dxp/process-automation/forms/form-rules/using-the-autofill-rule
  
  

• I set up a DDMRestDataProvider as follows:

  Read Access for Guest allowed

  URL: https://restcountries.com/v3.1/name/deutschland

  Outputs:

  Path: $..name.common

  Type: Text field

  Label: "Name Common"

Environment

• Liferay DXP 7.4

Resolution

• Currently the returned result is in a JSONArray, due to the usage of the indefinite path: $..name.common . 
• That is the reason why the text field cannot be autofilled with the value, since the return is not a single value.
• If you will use a path that is a definite path instead of an indefinite path, it should return a single value.
• JsonPath library's documentation
   
  

  A path is indefinite if it contains:

  • .. - a deep scan operator
  • ?(<expression>) - an expression
  • [<number>, <number> (, <number>)] - multiple array indexes

  Indefinite paths always returns a list (as represented by current JsonProvider).

   
• Recommended solution: changing the path to $.[0].name.common would change it to a definite path and the expectation would be that a single value is returned.
• Note: this is a proof of concept and ultimately it is up to you to decide on how to configure a Data Provider for your particular use-case.
  
• Additionally, you will also need to set View permission for the Guest user on the Data provider, in order to get the text field autofilled for the guests.