lab/VisitorArchive.R

In j2scode/NLPStudio: Natural Language Processing Environment

#==============================================================================#
#                             VisitorArchive                                   #
#==============================================================================#
#' VisitorArchive
#'
#' \code{VisitorArchive} Class responsible for archiving files associated with
#' objects in the NLPStudio package. Files are archived to folders designated
#' by the class of the object to which the files are associated.
#'
#' \strong{Visitor Class Family  Overview:}
#'
#' The Visitor family of classes is an implementation of the visitor
#' pattern documented in the book "Design Patterns: Elements of Reusable
#' Object-Oriented Software" by Erich Gamma, Richard Helm, Ralph Johnson
#' and John Vlissides (hence Gang of Four). This pattern allows operations
#' to be defined without changing the clases of the elemnts upon which
#' it operates.
#'
#' \strong{Visitor Class Family Participants:}
#' The participants of the Visitor class family are:
#' \itemize{
#'  \item Visitor0: This class which specifies an abstract interface for all concrete visitors.
#'  \item VisitorArchive This class archives the files associated with a designated object.
#'  \item VisitorRestore This class restores files associated with from archives the files associated with a designated object.
#'  \item VisitorOrphan: Visitor class responsible for moving an object's files to the orphan directory when the object has been removed from a lab or a collection.
#'  }
#'
#' \strong{Visitor Class Family Collaborators:}
#' The collaborators of the Visitor0 class are:
#' \itemize{
#'  \item Lab: Class for creating and managing documents and workflows.
#'  \item DocumentCollection: A composite class participant of the Document0 composite class which creates and manages collections of documents
#'  \item Document: A leaf class participant of the Document0 composite class. Elements include individual documents.
#'  }
#'
#' The methods are as follows:
#' \itemize{
#'  \item{\code{visitLab(lab)}}{Base method for visiting a object of the Lab class.}
#'  \item{\code{visitDocumentCollection(collection)}}{Base method visiting a object of the DocumentCollection class.}
#'  \item{\code{visitDocument(document)}}{Base method visiting a object of the Document class.}
#' }
#'
#' @param lab An object of the Lab class.
#' @param collection An object of the DocumentCollection class.
#' @param document An object of the Document class.
#' @param stateId A unique identifier given to each object state which is saved.
#'
#' @docType class
#' @author John James, \email{jjames@@datasciencesalon.org}
#' @family Visitor Classes
#' @export
VisitorArchive <- R6::R6Class(
  classname = "VisitorArchive",
  inherit = Visitor0,
  lock_objects = FALSE,
  lock_class = FALSE,

  private = list(
    ..stateId = character(0),
    ..class = character(0),
    ..objectName = character(0),
    ..path = character(0),
    ..fileName = character(0),
    ..files = character(0),
    ..requested = character(0),
    ..completed = character(0),

    archive = function(stateId, object, directory) {

      # Validate Parameters
      if (missing(stateId)) {
        v <- Validator0$new()
        v$notify(class = "VisitorArchive", method = "archive",
                 fieldName = "stateId", value = "", level = "Error",
                 msg = paste("StateId is missing with no default.",
                             "See ?VisitorArchive for further assistance."),
                 expect = NULL)
        stop()
      }

      if (missing(object)) {
        v <- Validator0$new()
        v$notify(class = "VisitorArchive", method = "archive",
                 fieldName = "object", value = "", level = "Error",
                 msg = paste("Object is missing with no default.",
                             "See ?VisitorArchive for further assistance."),
                 expect = NULL)
        stop()
      }

      v <- ValidatorClass$new()
      if (v$validate(class = "VisitorArchive", method = "archive",
                     fieldName = "object", value = object, level = "Error",
                     msg = paste("The object variable is not a valid R6 object.",
                                 "See ?VisitorArchive for further assistance."),
                     expect = c("Lab", "DocumentCollection", "Document")) == FALSE) {
        stop()
      }

      # Obtain object information
      o <- object$exposeObject()

      # Format object variables
      private$..stateId <-  stateId
      private$..class <-  class(lab)[1]
      private$..objectName <-  o$name
      private$..path <-  file.path(directory, o$name)
      private$..fileName <- paste0(private$..stateId, "-", private$..class, "-class-object-files")
      private$..files <- list.files(path = o$path, all.files = TRUE, full.names = TRUE,
                                    recursive = TRUE, include.dirs = TRUE)
      private$..requested <- Sys.time()

      # Execute archive
      if (length(private$..files) == 0) {
        private$..path <- character(0)
      } else {
        zip(file.path(private$..path, private$..fileName), private$..files)
      }

      private$..completed <- Sys.time()
    }
  ),

  public = list(

    visitLab = function(stateId, lab) {

      # Obtain directories
      dirs <- nlpStudio$getPaths()

      # Call archive function
      private$archive(stateId, lab, dirs$archivesLabs)

      invisible(self)

    },

    visitDocumentCollection = function(stateId, collection) {

      # Obtain directories
      dirs <- nlpStudio$getPaths()

      # Call archive function
      private$archive(stateId, collection, dirs$archivesCollections)

      invisible(self)
    },

    visitDocument = function(stateId, document) {

      # Obtain directories
      dirs <- nlpStudio$getPaths()

      # Call archive function
      private$archive(stateId, document, dirs$archivesDocuments)

      invisible(self)
    },

    getArchive = function() {
      a <- list(
        stateId <- private$..stateId,
        class = private$..class,
        objectName = private$..objectName,
        path = private$..path,
        fileName = private$..fileName,
        files = private$..files,
        requested = private$..requested,
        completed = private$..completed
      )
      return(a)
    }
  )
)