Add Jump Start example stock-api-plumber (#66)

* Add Jump Start example stock-api-plumber

* Bump version for release

* Update extension to R 4.2.3

* Update manifest using R 4.4.3, remove renv.lock

* Add minimumConnectVersion

* Try R 4.4.0

* Update README to reflect correct R version

* Update manifest description

Author: cgraham-rs

.github/workflows/extensions.yml

@@ -34,6 +34,7 @@ jobs:
             quarto-stock-report-python: extensions/quarto-stock-report-python/**
             portfolio-dashboard: extensions/portfolio-dashboard/**
             quarto-document: extensions/quarto-document/**
+            stock-api-plumber: extensions/stock-api-plumber/**
             stock-api-flask: extensions/stock-api-flask/**
             landing-page: extensions/landing-page/**
             stock-api-fastapi: extensions/stock-api-fastapi/**

.gitignore

@@ -1,6 +1,7 @@
 # RStudio
 .Rproj.user
 **/renv/
+.Rprofile
 
 # Quarto
 .quarto/

extensions/stock-api-plumber/README.md

@@ -0,0 +1,16 @@
+# Stock Pricing Service
+
+## About this example
+
+An API allows you to turn your models into production services that other tools and teams can use. APIs are a great way for software engineering teams to use your models without translating them into different languages.
+
+
+## Learn more
+
+* [Plumber Introduction](https://www.rplumber.io/)
+* [Plumber Documentation](https://www.rplumber.io/docs/)
+
+## Requirements
+
+* Posit Connect license allows API publishing
+* R version 4.4.0 or higher

extensions/stock-api-plumber/manifest.json

@@ -0,0 +1,73 @@
+#* @apiTitle Stock Information API
+#* @apiVersion 1.0.0
+#* @apiDescription This Plumber API surfaces the ability to programmatically request price history or a number representing the relative volatility of a stock ticker
+
+library(dplyr)
+
+valid_tickers <- c(
+  Apple = "AAPL",
+  Amazon = "AMZN",
+  Facebook = "FB",
+  Google = "GOOG",
+  Intel = "INTC",
+  Microsoft = "MSFT"
+)
+
+all_data <- readRDS("stock_data.rds") %>%
+  as_tibble()
+
+get_price_data <- function(data, ticker = "AMZN", from = "2010-01-01") {
+  data %>%
+    filter(
+      ticker == {{ ticker }},
+      date >= as.Date(from, format="%Y-%m-%d")
+    ) %>%
+    collect()
+}
+
+#* Protect against an invalid ticker
+#* @filter checkTicker
+function(req, res) {
+  if (!is.null(req$args$ticker) && !req$args$ticker %in% valid_tickers) {
+    res$status <- 400
+    return(
+      list(
+        error = paste(
+          "Invalid ticker. Please use one of",
+          paste(
+            "'", valid_tickers, "'",
+            sep = "", collapse = ", "
+          )
+        )
+      )
+    )
+  } else {
+    plumber::forward()
+  }
+}
+
+#* @get /price
+#* @param ticker:character ticker symbol (MSFT; AMZN; AAPL; FB; GOOG)
+#* @response 200 Returns price for ticker
+#* @response 400 Bad ticker
+#* @response 500 Bad ticker
+#* @response default Returns price for ticker
+price <- function(ticker = "AMZN") {
+  get_price_data(all_data, ticker, "2010-01-01")
+}
+
+#* @get /volatility
+#* @param ticker:character ticker symbol (MSFT; AMZN; AAPL; FB; GOOG)
+#* @response 200 Returns volatility for ticker
+#* @response 400 Bad ticker
+#* @response 500 Bad ticker
+#* @response default Returns volatility for ticker
+volatility <- function(ticker = "AMZN") {
+  price <- get_price_data(all_data, ticker, "2010-01-01") %>%
+    select(date, adjusted) %>%
+    mutate(returns = (log(adjusted) - log(lag(adjusted)))) %>%
+    na.omit() %>%
+    summarize(volatility = var(returns))
+
+  list(ticker = ticker, volatility = price$volatility)
+}

extensions/stock-api-plumber/plumber.R

@@ -0,0 +1,13 @@
+Version: 1.0
+
+RestoreWorkspace: Default
+SaveWorkspace: Default
+AlwaysSaveHistory: Default
+
+EnableCodeIndexing: Yes
+UseSpacesForTab: Yes
+NumSpacesForTab: 2
+Encoding: UTF-8
+
+RnwWeave: Sweave
+LaTeX: pdfLaTeX