Handle empty factor level.

.github/workflows/R-CMD-check.yaml

@@ -35,7 +35,7 @@ jobs:
 
       - uses: r-lib/actions/setup-tinytex@v2
       - run: tlmgr --version
-      - run: tlmgr install colortbl grfext ae
+      - run: tlmgr install colortbl grfext ae tabu
       - run: tlmgr list --only-installed
       - uses: r-lib/actions/setup-r@v2
         with:

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: tables
 Title: Formula-Driven Table Generation
-Version: 0.9.25
+Version: 0.9.26
 Author: Duncan Murdoch
 Description: Computes and displays complex tables of summary statistics.
   Output may be in LaTeX, HTML, plain text, or an R
@@ -11,7 +11,7 @@ Depends: R (>= 2.12.0)
 Imports: stats, utils, knitr, htmltools
 Suggests: magrittr, kableExtra (>= 0.9.0), Hmisc, bookdown, rmarkdown,
           pkgdown, formatters, tinytable (>= 0.0.5)
-VignetteBuilder: knitr
+VignetteBuilder: rmarkdown
 URL: https://dmurdoch.github.io/tables/
 BugReports: https://github.com/dmurdoch/tables/issues
 SystemRequirements: pandoc (>= 1.12.3) for vignettes

NEWS.md

@@ -1,3 +1,10 @@
+# tables 0.9.26
+
+- A factor level of `""` caused an error when displayed.  It will
+now be changed to `" "` for display (issue #19).
+- The `VignetteBuilder` field in `DESCRIPTION` has been changed to
+`rmarkdown` so that Pandoc can be found even when it is not on the `PATH`.
+
 # tables 0.9.25
 
 - `PlusMinus()` and `Paste()` didn't handle formatting properly 

R/All.R

@@ -39,7 +39,7 @@ All <- function(df,
       else
         next
 
-      f1 <- call("*", call("Heading", as.name(names[i])),
+      f1 <- call("*", call("Heading", makeName(names[i])),
                  value)
       if (is.null(f))
         f <- f1

R/RowFactor.R

@@ -60,7 +60,7 @@ RowFactor <- function(x, name = deparse(expr), levelnames=levels(x),
     	    test <- call("labelSubset",
     	                 subset = call("==", call("as.integer", call("as.factor", expr)), i),
     	                 label = deparse(expr))
-            term <- call("*", call("Heading", as.name(catname)), 
+            term <- call("*", call("Heading", makeName(catname)), 
                               test)
             if (i == 1)
             	f <- term

R/makeName.R

@@ -0,0 +1,6 @@
+makeName <- function(s) {
+  stopifnot(length(s) == 1)
+  if (!nchar(s))
+    s <- " "
+  as.name(s)
+}

R/tabular.R

@@ -553,10 +553,10 @@ expandFactors <- function(e, env) {
     	rhs <- expandFactors(e[[3]], env)
     	if (is.call(rhs) && deparse(rhs[[1]]) == "*"
     	 && is.call(rhs[[2]]) && deparse(rhs[[c(2,1)]]) == "Heading") {
-    	    rhs[[c(2,2)]] <- as.name(deparse(e[[2]]))
+    	    rhs[[c(2,2)]] <- makeName(deparse(e[[2]]))
     	    rhs
     	} else
-    	    call("*", call("Heading", as.name(deparse(e[[2]]))), rhs)
+    	    call("*", call("Heading", makeName(deparse(e[[2]]))), rhs)
     } else if (op == ".Format" || op == "Heading" || 
                op == "Justify" || op == "Percent" || 
     	       op == "Arguments" || op == "DropEmpty")