flextable in Rmarkdown docx not printing within if statement if other text - r

Question

I'm trying to use the package flextable to get some nicely formatted tables in my Rmarkdown (going to word file). The tables work just fine in general but if I put it within an if statement, if there is anything else being printed from the if statement I don't see the table. Any ideas what's going on?
Update Jan 2020 for any people still looking at this
As of version 0.5.5 of flextable there is a new function docx_value to address this, I have updated the answer to reflect this so that other people don't use the complicated workarounds now there is a simple solution.
My example (run all together) :
---
title: "Testing"
output:
word_document:
reference_docx: styles.docx
---
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```
## R Markdown
```{r defaults}
library(pander)
library(knitr)
library(flextable)
```
1st test works fine - no if statement and new lines either side of table
## test 1 table no if statemnets
```{r test1, echo = FALSE, results = 'asis'}
test <- data.frame (c = 1:5, x = 6:10)
testft <- flextable(test)
testft
```
2nd test has an if statement with no other text and works fine
## test 2 if statement no other text
```{r test2, echo = FALSE, results = 'asis'}
RunTable <- TRUE
if(RunTable){
testft
}
```
But if I try and add other outputs in my if statement, either with or without new line breaks I don't get any table in my output
## test 3 if statement with other text
```{r test3, echo = FALSE, results = 'asis'}
#Hack so dat works up to year 2047 as cpp functions in padr can't handle data beyond 2038
#Get Daily Values
RunTable <- TRUE
if(RunTable){
print("before ")
testft
print("after ")
}
```
## test 4 if statement with other text and newlines
```{r test4, echo = FALSE, results = 'asis'}
RunTable <- TRUE
if(RunTable){
print("if with linebreak before ")
cat(" \n")
knit_print(testft)
cat(" \n")
print("if with linebreak after ")
}
```
Output:

Answer 1

You can use chunk option results = 'asis' and write the openxml content with format as following
## test 4 if statement with other text and newlines
```{r test4, echo = FALSE, results = 'asis'}
RunTable <- TRUE
if(RunTable){
print("if with linebreak before ")
cat(" \n")
cat(
paste(
"\n```{=openxml}",
format(testft, type = "docx"),
"```\n", sep = "\n")
)
cat(" \n")
print("if with linebreak after ")
}
```

Answer 2

Not sure if you would consider a different package, but this seems to work:
---
title: "Testing"
output:
word_document
---
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE, fig.height=1.5, fig.width=3, fig.align='right', fig.align = "center")
```
## R Markdown
```{r defaults}
library(pander)
library(knitr)
library(flextable)
library(tableHTML)
```
## test 1 table no if statemnets
```{r test1, echo = FALSE}
test <- data.frame (c = 1:5, x = 6:10)
tab <- tableHTML(test, widths = c(60, 60), rownames = FALSE) %>% add_theme('scientific')
tab %>% tableHTML_to_image()
```
## test 2 if statement no other text
```{r test2, echo = FALSE}
RunTable <- TRUE
if(RunTable){
tab %>% tableHTML_to_image()
}
```
```{r test3, echo = FALSE}
#Hack so dat works up to year 2047 as cpp functions in padr can't handle data beyond 2038
#Get Daily Values
RunTable <- TRUE
if(RunTable){
print("before ")
tab %>% tableHTML_to_image()
print("after ")
}
```
## test 4 if statement with other text and newlines
```{r test4, echo = FALSE}
RunTable <- TRUE
if(RunTable){
print("if with linebreak before ")
cat(" \n")
tab %>% tableHTML_to_image()
cat(" \n")
print("if with linebreak after ")
}
For example, you can see test 4 as an output:
A couple of notes:
You can format the table in the exact way you want.
The code produces an image.

Answer 3

I presume your problem is related to this issue.
Changing the problematic chunks like this seems to work:
## test 3 if statement with other text
```{r test3, echo = FALSE}
RunTable <- TRUE
if(RunTable){
text <- c(
"before ",
knit_print(testft),
"after "
)
asis_output(paste(text, collapse = "\n"))
}
```
## test 4 if statement with other text and newlines
```{r test4, echo = FALSE}
RunTable <- TRUE
if(RunTable){
text <- c(
"if with linebreak before ",
" \\newline",
knit_print(testft),
" \\newline\n",
"if with linebreak after "
)
asis_output(paste(text, collapse = "\n"))
}
```
Regarding the last one:
I had to use \\newline to actually insert an extra blank line before the table.
I don't know why an extra \n is needed for the blank line after, it wouldn't work for me otherwise.
Just to test, I tried adding several \\newline entries, both before and after, but one blank line was the most I could get.

Answer 4

Update Jan 2020 for any people still looking at this
As of version 0.5.5 of flextable there is a new function docx_value to address this, as described in the package news:
flextable 0.5.5
new features
new function docx_value to let display flextables from non top level
calls inside R Markdown document.