Create remove_column.R

Added a function to remove a column after the kable is made
diff --git a/R/remove_column.R b/R/remove_column.R
new file mode 100644
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--- /dev/null
+++ b/R/remove_column.R
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+#' Remove columns
+#'
+#' @param kable_input Output of [knitr::kable()] with format specified
+#' @param columns A numeric value or vector indicating in which column(s) rows need to be removed
+#'
+#' @export
+#'
+#' @examples
+#' mtcars %>% 
+#' kable() %>% 
+#'     remove_column(2:3)
+function (kable_input, columns) {
+    kable_format <- attr(kable_input, "format")
+    if (!kable_format %in% c("html", "latex")) {
+        warning("Please specify format in kable. kableExtra can customize either ", 
+                "HTML or LaTeX outputs. See https://haozhu233.github.io/kableExtra/ ", 
+                "for details.")
+        return(kable_input)
+    }
+    if (kable_format == "html") {
+        return(remove_column_html(kable_input, columns))
+    } else if (kable_format == "latex") {
+        stop("Removing columns was not implemented for latex kables yet")
+    }
+}
+
+remove_column_html <- function (kable_input, columns) {
+    kable_attrs <- attributes(kable_input)
+    kable_xml <- kable_as_xml(kable_input)
+    kable_tbody <- xml_tpart(kable_xml, "tbody")
+    kable_thead <- xml_tpart(kable_xml, "thead")
+    
+    cell_topleft <- xml2::xml_child(kable_thead, 1) %>% 
+        xml2::xml_child(1) %>% 
+        xml2::xml_text() %>% 
+        stringr::str_trim()
+    has_rownames <- cell_topleft==""
+    if(has_rownames) columns <- columns+1
+    
+    body_rows <- xml2::xml_length(kable_tbody)
+    for(i in 1:body_rows){
+        for(j in columns){
+            target_row <- xml2::xml_child(kable_tbody, i)
+            target_cell <- xml2::xml_child(target_row, j)
+            xml2::xml_remove(target_cell)
+        }
+    }
+    target_row_head <- xml2::xml_child(kable_thead, 1)
+    for(j in columns){
+        target_cell_head <- xml2::xml_child(target_row_head, j)
+        xml2::xml_remove(target_cell_head)
+    }
+    out <- as_kable_xml(kable_xml)
+    attributes(out) <- kable_attrs
+    if (!"kableExtra" %in% class(out)) 
+        class(out) <- c("kableExtra", class(out))
+    
+    return(out)
+}