Nested List Parsing with jsonlite

This is the second time that I have faced this recently, so I wanted to reach out to see if there is a better way to parse dataframes returned from jsonlite when one of elements is an array stored as a column in the dataframe as a list.

I know that this part of the power with jsonlite, but I am not sure how to work with this nested structure. In the end, I suppose that I can write my own custom parsing, but given that I am almost there, I wanted to see how to work with this data.

For example:

## options
options(stringsAsFactors=F)

## packages
library(httr)
library(jsonlite)

## setup
gameid="2015020759"
SEASON = '20152016'
BASE = "http://live.nhl.com/GameData/"
URL = paste0(BASE, SEASON, "/", gameid, "/PlayByPlay.json")

## get the data
x <- GET(URL)

## parse
api_response <- content(x, as="text")
api_response <- jsonlite::fromJSON(api_response, flatten=TRUE)

## get the data of interest
pbp <- api_response$data$game$plays$play
colnames(pbp)

And exploring what comes back:

> class(pbp$aoi)
[1] "list"
> class(pbp$desc)
[1] "character"
> class(pbp$xcoord)
[1] "integer"

From above, the column pbp$aoi is a list. Here are a few entries:

> head(pbp$aoi)
[[1]]
[1] 8465009 8470638 8471695 8473419 8475792 8475902

[[2]]
[1] 8470626 8471276 8471695 8476525 8476792 8477956

[[3]]
[1] 8469619 8471695 8473492 8474625 8475727 8476525

[[4]]
[1] 8469619 8471695 8473492 8474625 8475727 8476525

[[5]]
[1] 8469619 8471695 8473492 8474625 8475727 8476525

[[6]]
[1] 8469619 8471695 8473492 8474625 8475727 8475902

I don't really care if I parse these lists in the same dataframe, but what do I have for options to parse out the data?

I would prefer to take the data out of out lists and parse them into a dataframe that can be "related" to the original record it came from.

Thanks in advance for your help.