Conditionally display a block of text in R Markdown

Question

I am using knitr to parse an R Markdown document . Is there a way to conditionally display a block of text in R Markdown depending on a variable in the environment I pass i

Answer 1

Here's a tweak to Paul Boardman's approach that gives proper markup in the output.

```{r setup, echo=FALSE}
show_text <- FALSE
```

```{r conditional_block, echo=FALSE, results='asis', eval=show_text}
cat("## Hey look, a heading!

lorem ipsum dolor emet...")
```

Even better, if we invoke the python engine to generate our output, we can use triple quoting to easily handle text that contains single or double quotes without needing to do anything fancy:

```{python, conditional_block_py, echo=FALSE, results='asis', eval=show_cond_text}
print("""
## Still a heading

Block of text with 'single quotes' and "double quotes"
""")
```