我可以强制knitr将“\\ n”解释为传递给R函数的字符串中的实际换行符吗？

Question

I am trying to use knitr to knit the following markdown to HTML from an .Rmd file using RStudio:

NOTE: This code will generate an error since you don't have access to the server I am querying, but the problematic HTML will still render and my question just concerns the formatting of the code in the HTML file - not the output from R.

SQL Code 

```{sql}
select 
  count(*) child_count
  ,year(eps_begin) year_plc
from vw_episodes
where eps_begin between '2009-01-01' and '2010-12-31'
  and fl_dur_7 = 0
group by 
  year(eps_begin)
```

R Code

```{r }
sqlQuery(cn, 
         "select 
                count(*) child_count
                ,year(eps_begin) year_plc
              from vw_episodes
              where eps_begin between '2009-01-01' and '2010-12-31'
                and fl_dur_7 = 0
              group by 
                year(eps_begin)")

```

My issue concerns the formatting of the R code when I knit to HTML. I would like the SQL code that is passed to the sqlQuery() function to be formatted similarly to the code that is produced in the SQL chunk. However, based on the HTML produced, knitr does not appear to be interpreting the \\n in the string as an actual line feed - it's just interpreting it as text.

The resulting HTML (for the R chunk) looks like this:

<pre><code class="r">sqlQuery(cn, &quot;select \n                count(*) child_count\n                ,year(eps_begin) year_plc\n              from vw_episodes\n              where eps_begin between &#39;2009-01-01&#39; and &#39;2010-12-31&#39;\n                and fl_dur_7 = 0\n              group by \n                year(eps_begin)&quot;)
</code></pre>

When what I really want is something like this:

<pre><code class="r">sqlQuery(cn, 
    &quot;select
        count(*) child_count
        ,year(eps_begin) year_plc
    from vw_episodes
    where eps_begin between &#39;2009-01-01&#39; and &#39;2010-12-31&#39;     
        and fl_dur_7 = 0
    group by 
        year(eps_begin)&quot;)
</code></pre>

Any thoughts on how I can knit to HTML and still preserve the line feeds in strings that are passed to R functions?

Answer 1

Update on 2017/09/21: the chunk option tidy defaults to FALSE in the current version of knitr , so it is no longer necessary to set it (there is no harm doing so, though).

---

That was due to the default reformatting of the code using the formatR package; you can turn it off by tidy=FALSE :

```{r tidy=FALSE}