dygraphs legend outside plot in shiny app for multiple plots - r

Question

I have this shiny app where I'm plotting several dygraphs. Unfortunately, I dont't know how many plots there will be plottet. It may vary from time to time. So I came up with using uiOutput and renderUI to build an app that reacts on the number of plots. See https://shiny.rstudio.com/articles/dynamic-ui.html
Now I wnat to show the legend of each dygraph outside the respective plot as was shown here: Is there a way to add legend next to a dygraph in R, not exactly on the plot?
My problem is now that the <div> elements of the legend do not have the same height as the ones of the plots.
My code is:
UI:
library(dygraphs)
shinyUI(fluidPage(
titlePanel("Simple example"),
sidebarLayout(
sidebarPanel(),
mainPanel(
fluidRow(column(10, uiOutput("graphs")),
column(2, uiOutput("legends")))
)
)
))
server:
library(dygraphs)
library(xts)
shinyServer(function(input, output, session) {
# load xts sample data
data("sample_matrix")
sample.xts <- as.xts(sample_matrix)
output$graphs <- renderUI({
plot_output_list <- lapply(1:3, function(i) {
dygraphOutput(paste0('div_graph_', i))
})
})
output$legends <- renderUI({
legend_output_list <- lapply(1:3, function(i) {
htmlOutput(paste0("div_legende",i), height = "400px")
})
})
# do the plotting
lapply(1:3, function(i) {
output[[paste0('div_graph_', i)]] <- renderDygraph({
dygraph(sample.xts[,i],main=i)%>%
dyLegend(labelsDiv = paste0("div_legende",i), show = "always")
})
})
})
This leads to this plot, where you can see the legends of all three plots are directly pasted together. I want them to be right of their respective plot.

Answer 1

I got it.
Creating a plotOutput and an empty plot does the trick:
Ui stays the same.
Server:
library(dygraphs)
library(xts)
shinyServer(function(input, output, session) {
data("sample_matrix")
sample.xts <- as.xts(sample_matrix)
output$graphs <- renderUI({
plot_output_list <- lapply(1:3, function(i) {
dygraphOutput(paste0('div_graph_', i))
})
})
output$legends <- renderUI({
legend_output_list <- lapply(1:3, function(i) {
plotOutput(paste0("div_legende",i), height = "400px")
})
})
lapply(1:3, function(i) {
output[[paste("div_legende",i)]] <- renderPlot(
plot(1,1,type="n",xaxt="n",yaxt="n",ylab="",xlab="",bty="n"),
height = "400px"
)
output[[paste0('div_graph_', i)]] <- renderDygraph({
dygraph(sample.xts[,i],main=i)%>%
dyLegend(labelsDiv = paste0("div_legende",i),
show = "always")
})
})
})