mtcars_as_a_service.R

# mtcars as as service 
# Create a JSON API for your data with GitHub + Blockspring
# This script will filter rows of mtcars based on API parameters

# import relevant libraries

suppressMessages(library(dplyr))
suppressMessages(library(RJSONIO))

# Get data from GitHub

mtcars_raw <- tempfile()
download.file("https://gist.githubusercontent.com/seankross/a412dfbd88b3db70b74b/raw/c2c6256d803967caa26d6fca231152c418438771/mtcars.csv", 
    mtcars_raw, method = "curl", quiet = TRUE)
mtcars_github <- read.csv(mtcars_raw)

# Read values from Blockspring API and filter data accordingly.

mtcars_result <- filter(mtcars_github, 
                        mpg >= mpg_min, mpg <= mpg_max,
                        cyl >= cyl_min, cyl <= cyl_max,
                        disp >= disp_min, disp <= disp_max,
                        hp >= hp_min, hp <= hp_max,
                        drat >= drat_min, drat <= drat_max,
                        wt >= wt_min, wt <= wt_max,
                        qsec >= qsec_min, qsec <= qsec_max,
                        vs >= vs_min, vs <= vs_max,
                        am >= am_min, am <= am_max,
                        gear >= gear_min, gear <= gear_max,
                        carb >= carb_min, carb <= carb_max)

# cat() the result so only pure JSON is returned from the POST request.

cat(RJSONIO::toJSON(mtcars_result))