In ropensci/elasticdsl: Elasticsearch DSL

elasticdsl

library("knitr")
hook_output <- knitr::knit_hooks$get("output")
knitr::knit_hooks$set(output = function(x, options) {
   lines <- options$output.lines
   if (is.null(lines)) {
     return(hook_output(x, options))  # pass to default hook
   }
   x <- unlist(strsplit(x, "\n"))
   more <- "..."
   if (length(lines)==1) {        # first n lines
     if (length(x) > lines) {
       # truncate the output, but add ....
       x <- c(head(x, lines), more)
     }
   } else {
     x <- c(if (abs(lines[1])>1) more else NULL,
            x[lines],
            if (length(x)>lines[abs(length(lines))]) more else NULL
           )
   }
   # paste these lines together
   x <- paste(c(x, ""), collapse = "\n")
   hook_output(x, options)
 })

knitr::opts_chunk$set(
  comment = "#>",
  collapse = TRUE,
  warning = FALSE,
  message = FALSE
)

An R DSL for Elasticsearch

Elasticsearch info

• Elasticsearch home page
• API docs
• This client is being developed under v1.4 of Elasticsearch.

Security

You're fine running ES locally on your machine, but be careful just throwing up ES on a server with a public IP address - make sure to think about security.

• Shield - This is a paid product provided by Elastic - so probably only applicable to enterprise users
• DIY security - there are a variety of techniques for securing your Elasticsearch. A number of resources are collected in a blog post - tools include putting your ES behind something like Nginx, putting basic auth on top of it, using https, etc.

Install elasticdsl

install.packages("devtools")
devtools::install_github("ropensci/elasticdsl")

library('elasticdsl')

Setup

Instructions for installing, upgrading, starting Elasticsearch, and loading example data at ropensci/elastic

Initialization

The function elastic::connect() is used before doing anything else to set the connection details to your remote or local elasticdslsearch store. The details created by connect() are written to your options for the current session, and are used by elasticdsl functions.

elastic::connect(es_port = 9200)

Set the index to use

index("shakespeare")

Print query as pretty json

index("shakespeare") %>%
  filter() %>% 
  ids(c(1, 2, 150)) %>%
  explain() # doesn't exist yet

Execute query

res <- index("shakespeare") %>%
  filter() %>% 
  ids(c(1, 2)) %>%
  exec()

n() to get number of results

index("shakespeare") %>%
  ids(c(1, 2)) %>%
  exec() %>% 
  n()

Request size

index("shakespeare") %>%
  filter() %>% 
  prefix(speaker = "we") %>%
  size(2) %>% 
  fields(play_name) %>% 
  exec() %>% 
  n()

Request certain fields

s <- index("shakespeare") %>%
  filter() %>% 
  prefix(speaker = "we") %>%
  size(2)

s %>% fields(play_name) %>% exec() %>% .$hits %>% .$hits

s %>% fields(play_name, text_entry) %>% exec() %>% .$hits %>% .$hits

s %>% fields(play_name, text_entry, line_id) %>% exec() %>% .$hits %>% .$hits

Filters vs. queries

Filters are boolean queries and are much more computationally efficient than queries.

Filters

prefix filter

index("shakespeare") %>%
  filter() %>% 
  prefix(speaker = "we") %>%
  exec() %>% 
  n()

ids filter

index("shakespeare") %>%
  filter() %>% 
  ids(c(1, 2, 150)) %>%
  exec() %>% 
  n()

Queries

geoshape query (filters have a much larger range of geo queries)

index("geoshape") %>%
  geoshape(field = "location", type = "envelope", coordinates = list(c(-30, 50), c(30, 0))) %>% 
  n()

Meta

• Please report any issues or bugs
• License: MIT
• Get citation information for elasticdsl in R doing citation(package = 'elasticdsl')
• Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.

ropensci/elasticdsl documentation built on May 18, 2022, 9:53 a.m.