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rjsonhttr

Downloading multiple JSON files from a website folder

I'm trying to download all the files with the word 'tree' from this link.

I know how to download them individually, but I can't figure out how to download them all at once, according to that conditions (has word 'tree').

Solution

  • This is likely to be very slow(see notes):

     library(dplyr)
library(rvest)
my_table<-read_html("https://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/json/")
my_table %>% 
  html_nodes(css="table") %>% 
  html_table() -> res
json_names<-res[[1]][,2]
json_names %>% 
  as_tibble() %>% 
  slice(3:nrow(.)) %>% 
  filter(grepl("tree",value)) %>% 
  pull(value) %>% 
  lapply(.,function(x) paste0("https://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/json/",
                                                x)) %>% 
  unlist() -> url_list

    Sample results:

     lapply(url_list[1:2],jsonlite::fromJSON)
[[1]]
[[1]]$xmlId
[1] "4355"

[[1]]$NOAAStudyId
[1] "2657"

[[1]]$studyName
[1] "Adams - Fernow Experimental Forest - QUPR - ITRDB WV003"

[[1]]$doi
[1] "https://doi.org/10.25921/jzj2-vy39"

    NOTE:

    On a *nix machine, I would use wget instead.