In jimrothstein/yt_api: R functions to use Google Youtube API

PURPOSE: DiagrammeR sketches for API, R talk

knitr::opts_chunk$set(echo = TRUE,
                      comment = "      ##",
                      error = TRUE,
                      collapse = TRUE)
library(DiagrammeR)

DiagrammeR::grViz("
  digraph rmarkdown {
    vector -> atomic -> character
    atomic -> numeric
    atomic -> logical
    numeric -> double
    numeric -> integer
    integer -> factor
    double  -> date
    double -> POSIXct
    vector -> list
  }
  ", height=600)

# 1. Make a play graph
tmp = DiagrammeR::grViz('digraph{a->b; c->a; c->b; c->d;}')

# 2. Convert to SVG, then save as png
tmp = DiagrammeRsvg::export_svg(tmp)
tmp = charToRaw(tmp) # flatten
rsvg::rsvg_png(tmp, "g.png") # saved graph as png in current working directory

##  webshot creates pdf (?) image of html page.
webshot::install_phantomjs()

tmp  <- DiagrammeR::grViz("
  digraph rmarkdown {
      server  -> client
  }
  ", height=600)


tmp = DiagrammeRsvg::export_svg(tmp)
tmp = charToRaw(tmp) # flatten
rsvg::rsvg_png(tmp, "g.png") # saved graph as png in current working directory