Autocomplete setting in the designer using IDesignerAutocompleteProvider

Sometimes it is very useful to give a small tip to the user, who is editing the scheme, to prompt him which value to specify for the parameter transferred into Action, Condition or Rule. Very often you've got a CheckRole Rule, which checks if a user executing the command has a role with the name transferred into the parameter (Value column in the designer). This is how it looks in the designer:

It is only logical that the system must show a list of roles a user can choose from. To realize that function, you need to do the following:

• write a class implementing the IDesignerAutocompleteProvider interface. Like this one, for example:

  public class AutoCompleteProvider : IDesignerAutocompleteProvider
  {
      public List<string> GetAutocompleteSuggestions(SuggestionCategory category,
          string name, string schemeCode)
      {
          if (category == SuggestionCategory.RuleParameter && name == "CheckRole")
          {
              return new List<string>(){"BigBoss", "Accountant"};
          }
  
          return null;
      }
  }

You can see from this code that you need to implement one method only - GetAutocompleteSuggestions. Input parameters for this method are:

• category - enumeration, which defines a scheme element the autocomplete list is called for. Possible values: RuleParameter, ActionParameter or ConditionParameter.
• name - Action, Condition or Rule name, the autocomplete list is displayed for. In this case autocomplete will work only if you have chosen the CheckRole Rule.
• schemeCode - the scheme code.
• specify your Autocomplete provider when configuring WorkflowRuntime

runtime.WithDesignerAutocompleteProvider(new AutoCompleteProvider());

After that a drop-down list of tips will be available to users. It will look like that: