How to render leaflet-maps in loops in RMDs with knitr

Question

I am currently fighting trying to get knitr to render my leaflet maps, taken from a collection to appear correctly in a rendered RMD html-output. I\'m already aware about some p

Answer 1

You need to put things in a tagList, and have that list print from the chunk. This just uses default settings for fig.show and results; it also uses the htmltools::h3() function to turn the title into an HTML title directly, not using the Markdown ### marker. (You might want h2 or h4 instead.)

---
title: "test3"
output: html_document
---

```{r setup, include=FALSE}
library(leaflet)
library(htmltools)
knitr::opts_chunk$set(echo = TRUE)
```

## Title 1

```{r echo=FALSE}
html <- list()
for (i in 1:4) {
  html <- c(html, 
            list(h3(paste0("Map Number ", i)),
                 leaflet() %>%
                 addTiles() %>%  # Add default OpenStreetMap map tiles
                 addMarkers(lng=174.768, lat=-36.852, popup="The birthplace of R")  
                 )
            )
}
tagList(html)
```