R/perform_cts_for_layer.R

In rsgl: An Implementation of the 'SGL' Graphics Language

add_trans_cols_from_aes <- function(aes_mappings, df, scales) {
  for (aes in names(aes_mappings)) {
    aes_mapping <- aes_mappings[[aes]]
    cta <- aes_mapping$cta
    if (is_transformation(cta)) {
      call_args <- list(
        cta, aes_mapping$column, df
      )
      if (aes %in% names(scales)) {
        call_args[["scale"]] <- scales[[aes]]
      } else {
        call_args[["scale"]] <- new_sgl_scale_linear()
      }
      if ("arg" %in% names(aes_mapping)) {
        call_args[["num_bins"]] <- aes_mapping$arg
      }
      df <- do.call(add_transformed_column, call_args)
    }
  }
  df
}

add_trans_cols_from_col_exprs <- function(col_exprs, df) {
  for (col_expr in col_exprs) {
    cta <- col_expr$cta
    if (is_transformation(cta)) {
      call_args <- list(
        cta, col_expr$column, df,
        scale = new_sgl_scale_linear()
      )
      if ("arg" %in% names(col_expr)) {
        call_args[["num_bins"]] <- col_expr$arg
      }
      df <- do.call(add_transformed_column, call_args)
    }
  }
  df
}

perform_cts_for_layer <- function(layer, df, scales) {
  aes_mappings <- layer$aes_mappings
  groupings <- layer$groupings
  collections <- layer$collections
  df <- add_trans_cols_from_aes(aes_mappings, df, scales)
  additional_group_cols <- groupings[
    !(groupings %in% aes_mappings)
  ]
  df <- add_trans_cols_from_col_exprs(additional_group_cols, df)
  additional_collect_cols <- collections[
    !(collections %in% aes_mappings) &
      !(collections %in% groupings)
  ]
  df <- add_trans_cols_from_col_exprs(additional_collect_cols, df)
  df
}