/// <summary>
/// Deletes grammar with id.
/// </summary>
/// <param name="grammarId">Id of grammar that should be deleted.</param>
/// <returns>
/// When rejected, an <see cref="Exception" /> with info about error that occured.
/// </returns>
public static IPromise DeleteGrammar(string grammarId)
{
if (!GrammarList.ContainsKey(grammarId))
{
return(Promise.Rejected(new ApplicationException("Delete grammar request error:\nRequested grammar not found.")));
}
return(WebAPI.DeleteGrammar(grammarId)
.Then(() => {
grammarList.Remove(grammarId);
SaveGrammarList();
}));
}