Several ggplotly figures from within if block in rmarkdown - ggplot2

Question

I am unable to generate an html file, from rmarkdown, which displays two or more ggplotly plots created inside an if block in a given code chunk.
My MWE rmarkdown source code follows:
---
title: Several ggplotly figures from within if block in rmarkdown
author: "Mauricio Calvao"
date: "February 27, 2017"
output:
html_document: default
---
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```
```{r}
library(ggplot2)
library(plotly)
```
## Outside if block:
I can have rmarkdown generate an html document with two ggplotly plots, outside of an if block in a given chunk:
```{r}
ggplotly(qplot(data = pressure, x = temperature, y = pressure))
ggplotly(qplot(data = pressure, x = pressure, y = temperature))
```
## Inside if block:
However, when I try the same code inside an if block, only the last plot shows up in the html document:
```{r}
if (TRUE) {
ggplotly(qplot(data = pressure, x = temperature, y = pressure))
ggplotly(qplot(data = pressure, x = pressure, y = temperature))
}
```
**How do I print two (or more plots, for that matter) from within an if block in the html document???**
The above is a MWE, but, in fact, in a more general setting I would have a large number of plots to be printed depending on several if else blocks...
Any suggestions are welcome!!

Answer 1

The answer is now available from the plotly reference.
In short, you either use:
subplot:
if (TRUE) {
p1= ggplotly(qplot(data = pressure, x = temperature, y = pressure))
p2= ggplotly(qplot(data = pressure, x = pressure, y = temperature))
subplot(p1, p2)
}
or taglist
if (TRUE) {
p1= ggplotly(qplot(data = pressure, x = temperature, y = pressure))
p2= ggplotly(qplot(data = pressure, x = pressure, y = temperature))
htmltools::tagList(list(p1, p2))
}