Data Validation Rules

Duncan Garmonsway

2017-11-25

What data validation rules are

Data validation rules control what constants can be entered into a cell, e.g. any whole number between 0 and 9, or one of several values from another part of the spreadsheet.

‘xlsx_validation()’ returns each of the data validation rules in an xlsx file, and the ranges of cells to which each rule applies.

Here is a rule that restricts input to integers between 0 and 9 inclusive, or no value (blank). If any other value is attempted, then an error message is displayed with the imaginative title “message title”, the informative body text “message body”, and a “stop” symbol.

library(tidyxl)
library(dplyr)
#>
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#>
#> filter, lag
#> The following objects are masked from 'package:base':
#>
#> intersect, setdiff, setequal, union
library(tidyr)
examples <- system.file("extdata/examples.xlsx", package = "tidyxl")
glimpse(xlsx_validation(examples)[1, ])
#> Observations: 1
#> Variables: 14
#> $ sheet <chr> "Sheet1"
#> $ ref <chr> "A106"
#> $ type <chr> "whole"
#> $ operator <chr> "between"
#> $ formula1 <chr> "0"
#> $ formula2 <chr> "9"
#> $ allow_blank <lgl> TRUE
#> $ show_input_message <lgl> TRUE
#> $ prompt_title <chr> "message title"
#> $ prompt_body <chr> "message body"
#> $ show_error_message <lgl> TRUE
#> $ error_title <chr> "error title"
#> $ error_body <chr> "error body"
#> $ error_symbol <chr> "stop"

The gamut of possible rules is given in the examples for xlsx_validation().

as.data.frame(xlsx_validation(examples))
#> sheet ref type operator formula1
#> 1 Sheet1 A106 whole between 0
#> 2 Sheet1 A108 list <NA> $B$108
#> 3 Sheet1 A110 date between 2017-01-01 00:00:00
#> 4 Sheet1 A111 time between 00:00:00
#> 5 Sheet1 A112 textLength between 0
#> 6 Sheet1 A114 whole notBetween 0
#> 7 Sheet1 A115,A121:A122 whole equal 0
#> 8 Sheet1 A116 whole notEqual 0
#> 9 Sheet1 A117 whole greaterThan 0
#> 10 Sheet1 A119 whole greaterThanOrEqual 0
#> 11 Sheet1 A120 whole lessThanOrEqual 0
#> 12 Sheet1 A118 whole lessThan 0
#> 13 Sheet1 A107 decimal notBetween 0
#> 14 Sheet1 A113 custom <NA> A113<=LEN(B113)
#> 15 Sheet1 A109 list <NA> $B$108
#> formula2 allow_blank show_input_message prompt_title
#> 1 9 TRUE TRUE message title
#> 2 <NA> TRUE TRUE <NA>
#> 3 2017-01-09 09:00:00 TRUE TRUE <NA>
#> 4 09:00:00 TRUE TRUE <NA>
#> 5 9 TRUE TRUE <NA>
#> 6 9 TRUE TRUE <NA>
#> 7 <NA> TRUE TRUE <NA>
#> 8 <NA> TRUE TRUE <NA>
#> 9 <NA> TRUE TRUE <NA>
#> 10 <NA> TRUE TRUE <NA>
#> 11 <NA> TRUE TRUE <NA>
#> 12 <NA> TRUE TRUE <NA>
#> 13 9 FALSE FALSE <NA>
#> 14 <NA> TRUE TRUE <NA>
#> 15 <NA> TRUE TRUE <NA>
#> prompt_body show_error_message error_title error_body error_symbol
#> 1 message body TRUE error title error body stop
#> 2 <NA> TRUE <NA> <NA> warning
#> 3 <NA> TRUE <NA> <NA> stop
#> 4 <NA> TRUE <NA> <NA> stop
#> 5 <NA> TRUE <NA> <NA> stop
#> 6 <NA> TRUE <NA> <NA> stop
#> 7 <NA> TRUE <NA> <NA> stop
#> 8 <NA> TRUE <NA> <NA> stop
#> 9 <NA> TRUE <NA> <NA> stop
#> 10 <NA> TRUE <NA> <NA> stop
#> 11 <NA> TRUE <NA> <NA> stop
#> 12 <NA> TRUE <NA> <NA> stop
#> 13 <NA> FALSE <NA> <NA> stop
#> 14 <NA> TRUE <NA> <NA> stop
#> 15 <NA> TRUE <NA> <NA> information

Joining rules to cells

There are no built-in functions for joining ranges like A1:D5,G8 to single cells like B3. For now, use the snippets in this section. In future I might develop a dplyr-like join function (this is hard currently because dplyr doesn’t yet join on arbitrary functions, or even the standard inequalities like >=). Help and advice would be gratefully accepted!

To join rules to cells, a naive method is to use the sheet and ref columns to match the sheet and address columns to the output of xlsx_cells().

rules <- xlsx_validation(examples)
cells <- filter(xlsx_cells(examples), row >= 106, col == 1)
rules
#> # A tibble: 15 x 14
#> sheet ref type oper… form… form… allo… show… prom… prom… show… erro…
#> <chr> <chr> <chr> <chr> <chr> <chr> <lgl> <lgl> <chr> <chr> <lgl> <chr>
#> 1 Shee… A106 whole betw… 0 9 T T mess… mess… T erro…
#> 2 Shee… A108 list <NA> $B$1… <NA> T T <NA> <NA> T <NA>
#> 3 Shee… A110 date betw… 2017… 2017… T T <NA> <NA> T <NA>
#> 4 Shee… A111 time betw… 00:0… 09:0… T T <NA> <NA> T <NA>
#> 5 Shee… A112 text… betw… 0 9 T T <NA> <NA> T <NA>
#> 6 Shee… A114 whole notB… 0 9 T T <NA> <NA> T <NA>
#> 7 Shee… A115… whole equal 0 <NA> T T <NA> <NA> T <NA>
#> 8 Shee… A116 whole notE… 0 <NA> T T <NA> <NA> T <NA>
#> 9 Shee… A117 whole grea… 0 <NA> T T <NA> <NA> T <NA>
#> 10 Shee… A119 whole grea… 0 <NA> T T <NA> <NA> T <NA>
#> 11 Shee… A120 whole less… 0 <NA> T T <NA> <NA> T <NA>
#> 12 Shee… A118 whole less… 0 <NA> T T <NA> <NA> T <NA>
#> 13 Shee… A107 deci… notB… 0 9 F F <NA> <NA> F <NA>
#> 14 Shee… A113 cust… <NA> A113… <NA> T T <NA> <NA> T <NA>
#> 15 Shee… A109 list <NA> $B$1… <NA> T T <NA> <NA> T <NA>
#> # ... with 2 more variables: error_body <chr>, error_symbol <chr>
cells
#> # A tibble: 93 x 21
#> sheet address row col is_blank data_type error logical numeric
#> <chr> <chr> <int> <int> <lgl> <chr> <chr> <lgl> <dbl>
#> 1 Sheet1 A106 106 1 F numeric <NA> NA 0
#> 2 Sheet1 A107 107 1 F numeric <NA> NA 0.100
#> 3 Sheet1 A108 108 1 F character <NA> NA NA
#> 4 Sheet1 A109 109 1 F character <NA> NA NA
#> 5 Sheet1 A110 110 1 F date <NA> NA NA
#> 6 Sheet1 A111 111 1 F date <NA> NA NA
#> 7 Sheet1 A112 112 1 F character <NA> NA NA
#> 8 Sheet1 A113 113 1 F numeric <NA> NA 10.0
#> 9 Sheet1 A114 114 1 F numeric <NA> NA - 1.00
#> 10 Sheet1 A115 115 1 F numeric <NA> NA 0
#> # ... with 83 more rows, and 12 more variables: date <dttm>,
#> # character <chr>, character_formatted <list>, formula <chr>,
#> # is_array <lgl>, formula_ref <chr>, formula_group <int>, comment <chr>,
#> # height <dbl>, width <dbl>, style_format <chr>, local_format_id <int>
inner_join(rules, cells, by = c("sheet" = "sheet", "ref" = "address"))
#> # A tibble: 9 x 33
#> sheet ref type oper… form… form… allo… show… prom… prom… show… erro…
#> <chr> <chr> <chr> <chr> <chr> <chr> <lgl> <lgl> <chr> <chr> <lgl> <chr>
#> 1 Sheet1 A106 whole betw… 0 9 T T mess… mess… T erro…
#> 2 Sheet1 A108 list <NA> $B$1… <NA> T T <NA> <NA> T <NA>
#> 3 Sheet1 A110 date betw… 2017… 2017… T T <NA> <NA> T <NA>
#> 4 Sheet1 A111 time betw… 00:0… 09:0… T T <NA> <NA> T <NA>
#> 5 Sheet1 A112 text… betw… 0 9 T T <NA> <NA> T <NA>
#> 6 Sheet1 A114 whole notB… 0 9 T T <NA> <NA> T <NA>
#> 7 Sheet1 A107 deci… notB… 0 9 F F <NA> <NA> F <NA>
#> 8 Sheet1 A113 cust… <NA> A113… <NA> T T <NA> <NA> T <NA>
#> 9 Sheet1 A109 list <NA> $B$1… <NA> T T <NA> <NA> T <NA>
#> # ... with 21 more variables: error_body <chr>, error_symbol <chr>,
#> # row <int>, col <int>, is_blank <lgl>, data_type <chr>, error <chr>,
#> # logical <lgl>, numeric <dbl>, date <dttm>, character <chr>,
#> # character_formatted <list>, formula <chr>, is_array <lgl>,
#> # formula_ref <chr>, formula_group <int>, comment <chr>, height <dbl>,
#> # width <dbl>, style_format <chr>, local_format_id <int>

Notice that only 9 cells were joined, even though 15 rules were defined. Surely at least 15 cells ought to be joined? The reason why they are not is that the cells for the other 6 rules don’t exist – rules can be defined for cells that have no value, and cells with no value are not returned by xlsx_cells(), otherwise all 17179869184 cells in a worksheet must be returned.

A more subtle reason for certain cells not to have joined successfully is that the ref column of the rules sometimes refers to more than one cell, and can even refer to several, non-contiguous ranges of cells. Specifically, the seventh rule’s ref column has A115,A121:A122.

Special treatment is needed here. Ideally, some kind of join function would be defined that can compare indidual cells with ranges. But I haven’t written one, so what follows is a workaround. First, the two ranges of cells must be unnested into A115 and A121:122. Then the range A121:122 must be ‘unranged’ into A121 and A122.

unrange <- function(x) {
limits <- cellranger::as.cell_limits(x)
rows <- seq(limits$ul[1], limits$lr[1])
cols <- seq(limits$ul[2], limits$lr[2])
rowcol <- expand.grid(rows, cols)
cell_addrs <- cellranger::cell_addr(rowcol[[1]], rowcol[[2]])
cellranger::to_string(cell_addrs, fo = "A1", strict = FALSE)
}
unnest_ref <- function(x, ref) {
UseMethod("unnest_ref")
}
unnest_ref.default <- function(x, ref_col = ref) {
stopifnot(is.character(x), length(x) == 1L)
refs <- unlist(strsplit(x, ",", fixed = TRUE))
unlist(lapply(refs, unrange))
}
unrange("A121:A122")
#> [1] "A121" "A122"
unnest_ref("A115,A121:A122")
#> [1] "A115" "A121" "A122"

The unnest_ref() function can also be defined for whole data frames, unnesting them by a column of references.

unnest_ref.data.frame <- function(x, ref_col) {
ref <- rlang::enquo(ref_col)
x[[rlang::quo_name(ref)]] <- lapply(x[[rlang::quo_name(ref)]], unnest_ref)
tidyr::unnest(x, rlang::UQ(ref))
}
(nested_rule <- slice(rules, 7))
#> # A tibble: 1 x 14
#> sheet ref type oper… form… form… allo… show… prom… prom… show… erro…
#> <chr> <chr> <chr> <chr> <chr> <chr> <lgl> <lgl> <chr> <chr> <lgl> <chr>
#> 1 Sheet1 A115… whole equal 0 <NA> T T <NA> <NA> T <NA>
#> # ... with 2 more variables: error_body <chr>, error_symbol <chr>
unnest_ref(nested_rule, ref)
#> # A tibble: 3 x 14
#> sheet type oper… form… form… allo… show… prom… prom… show… erro… erro…
#> <chr> <chr> <chr> <chr> <chr> <lgl> <lgl> <chr> <chr> <lgl> <chr> <chr>
#> 1 Sheet1 whole equal 0 <NA> T T <NA> <NA> T <NA> <NA>
#> 2 Sheet1 whole equal 0 <NA> T T <NA> <NA> T <NA> <NA>
#> 3 Sheet1 whole equal 0 <NA> T T <NA> <NA> T <NA> <NA>
#> # ... with 2 more variables: error_symbol <chr>, ref <chr>

Finally the new data frame of rules can be joined to a data frame of cells in any of the usual ways, via the sheet and ref columns.

Problems with this approach occur with rules that are defined over large ranges of cells: the ‘unnesting’ of those ranges results in very long vectors of individual cell addresses, or (worse) huge data frames of rules. Such cases are commonplace, because rules are often defined for entire columns of a spreadsheet, and a column has 1048576 rows.