Conditional markup blocks?

[Keith Hughitt]

Hello,

Does anyone know if it is possible to conditionally knit blocks of markdown, etc.?

For example, it would be nice to be able to do something like:

```{r start}

if (x == TRUE) {

```

some text here...

```{r finish}

}

```

This would be useful to be able to mark off large sections of text that should only be displayed under certain conditions.

Keith

[Yihui Xie]

You can make use of child documents.

```{r main}
x = TRUE # or FALSE
```

Then

```{r test, child = if (x == TRUE) 'child-a.Rmd' else 'child-b.Rmd'}
```

Regards,
Yihui
--
Yihui Xie <xiey...@gmail.com>
Phone: 515-294-2465 Web: http://yihui.name
Department of Statistics, Iowa State University
2215 Snedecor Hall, Ames, IA

[Keith Hughitt]

Works perfect. Thanks, Yihui!

[Dean Attali]

Interesting workaround :)

Are there plans to add more concrete support for conditional blocks? A markdown document with several small conditional blocks will quickly get very messy and complicated if we need to use several different .Rmd files for this.

On Sunday, 16 June 2013 09:13:05 UTC-7, Keith Hughitt wrote:

Works perfect. Thanks, Yihui!

[Yihui Xie]

Sorry, it is a little bit complicated for me to implement. Jeff
Horner's brew package has done it long time ago, though:
http://cran.rstudio.com/web/packages/brew/

Regards,
Yihui
--
Yihui Xie <xiey...@gmail.com>

Web: http://yihui.name