Merge pull request #4 from The-Strategy-Unit/1-poc-trend

Add basic proof-of-concept app

Author: matt-dray

.Rbuildignore

@@ -1,4 +1,5 @@
 ^\.github$
+^\.Renviron\.example$
 ^\.Rproj\.user$
 ^\.vscode$
 ^app\.R$

.Renviron.example

@@ -0,0 +1,2 @@
+AZ_CONTAINER_INPUTS=
+AZ_STORAGE_EP=

DESCRIPTION

@@ -8,9 +8,21 @@ Description: A Shiny-app-in-a-package to explore data related to
 License: MIT + file LICENSE
 URL: https://github.com/The-Strategy-Unit/cpma-explorer
 BugReports: https://github.com/The-Strategy-Unit/cpma-explorer/issues
+Depends:
+    R (>= 4.1.0)
 Imports:
+    azkit,
+    bsicons,
     bslib,
-    shiny
+    dplyr,
+    ggplot2,
+    jsonlite,
+    purrr,
+    rlang,
+    shiny,
+    stringr
+Remotes:
+    The-Strategy-Unit/azkit
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
 RoxygenNote: 7.3.2

NAMESPACE

@@ -1,3 +1,5 @@
 # Generated by roxygen2: do not edit by hand
 
 export(run_app)
+importFrom(rlang,.data)
+importFrom(rlang,.env)

R/ZZZ.R

@@ -0,0 +1,2 @@
+#' @importFrom rlang .data .env
+NULL

R/add_external_resources.R

@@ -15,7 +15,6 @@ add_external_resources <- function() {
 #' @param ... character vectors, specifying subdirectory and file(s)
 #'     within your package. The default, none, returns the root of the app.
 #' @noRd
-#' @noRd
 app_sys <- function(...) {
-  system.file(..., package = "cpma-explorer")
+  system.file(..., package = "cpma.explorer")
 }

R/app_server.R

@@ -2,18 +2,57 @@
 #' @param input,output,session Internal parameters for {shiny}.
 #' @noRd
 app_server <- function(input, output, session) {
-  output$distPlot <- shiny::renderPlot({
-    x <- datasets::faithful[, 2]
-    bins <- seq(min(x), max(x), length.out = input$bins + 1)
-
-    # draw the histogram with the specified number of bins
-    graphics::hist(
-      x,
-      breaks = bins,
-      col = "darkgray",
-      border = "white",
-      xlab = "Waiting time to next eruption (in mins)",
-      main = "Histogram of waiting times"
+  # Data ----
+
+  container <- azkit::get_container(Sys.getenv("AZ_CONTAINER_INPUTS"))
+  rates <- azkit::read_azure_parquet(container, "rates", "dev")
+
+  # Reactives ----
+
+  selected_provider <- shiny::reactive(input$provider_select)
+  selected_strategy <- shiny::reactive(input$strategy_select)
+
+  rates_prepared <- shiny::reactive({
+    rates |>
+      dplyr::filter(
+        .data$provider == selected_provider(),
+        .data$strategy == selected_strategy()
+      ) |>
+      dplyr::arrange(.data$fyear)
+  }) |>
+    shiny::bindEvent(selected_provider(), selected_strategy())
+
+  # Observers ----
+
+  shiny::observe({
+    providers <- jsonlite::read_json(
+      app_sys("app", "data", "datasets.json"),
+      simplify_vector = TRUE
+    )
+    provider_choices <- purrr::set_names(names(providers), providers)
+    shiny::updateSelectInput(
+      session,
+      "provider_select",
+      choices = provider_choices
     )
   })
+
+  shiny::observe({
+    strategies <- jsonlite::read_json(
+      app_sys("app", "data", "mitigators.json"),
+      simplify_vector = TRUE
+    )
+    strategy_choices <- purrr::set_names(names(strategies), strategies)
+    shiny::updateSelectInput(
+      session,
+      "strategy_select",
+      choices = strategy_choices
+    )
+  })
+
+  # Outputs ----
+
+  output$rates_plot <- shiny::renderPlot({
+    rates_prepared() |> plot_rates()
+  })
 }

R/app_ui.R

@@ -1,24 +1,39 @@
 #' The application User-Interface
-#' @param request Internal parameter for `{shiny}`.
+#' @param request Internal parameter for shiny.
 #' @noRd
 app_ui <- function(request) {
   bslib::page_sidebar(
-    title = "Old Faithful Geyser Data",
-    lang = "en",
-    theme = bslib::bs_theme(primary = "#005EB8", base_font = "Frutiger"),
+    title = "CPMA Explorer",
     sidebar = bslib::sidebar(
-      shiny::sliderInput(
-        "bins",
-        "Number of bins:",
-        min = 1,
-        max = 50,
-        value = 30
+      shiny::selectInput(
+        "provider_select",
+        "Choose a provider:",
+        choices = NULL
+      ),
+      shiny::selectInput(
+        "strategy_select",
+        "Choose a strategy:",
+        choices = NULL
       )
     ),
 
     bslib::card(
-      bslib::card_header("A nice plot"),
-      shiny::plotOutput("distPlot")
+      fill = FALSE,
+      bslib::card_header(
+        class = "bg-warning",
+        bsicons::bs_icon("exclamation-triangle"),
+        "Warning"
+      ),
+      "This application is in development and its output has not been verified.
+      The information presented here should not be relied on as fact."
+    ),
+
+    bslib::card(
+      bslib::card_header("Trend in rates"),
+      bslib::card_body(
+        shiny::plotOutput("rates_plot")
+      ),
+      full_screen = TRUE
     )
   )
 }

R/fct_plot.R

@@ -0,0 +1,28 @@
+#' Plot Trend in Rates
+#' @param rates_df A data.frame. Must contain columns given by `fyear_col` and
+#'     `rate_col`. Pre-filtered for a given provider and strategy. One row per
+#'     financial year.
+#' @param fyear_col Character. Name of the column in `rates_df` containing the
+#'     financial year in the form `"2023/24"`.
+#' @param rate_col Character. Name of the column in `rates_df` containing the
+#'     rate value (the type of which is dependent on the strategy).
+plot_rates <- function(rates_df, fyear_col = "fyear", rate_col = "rate") {
+  x_breaks <- rates_df[[fyear_col]]
+  x_labels <- enstring_fyear(x_breaks)
+
+  rates_df |>
+    ggplot2::ggplot(ggplot2::aes(
+      x = .data[[fyear_col]],
+      y = .data[[rate_col]]
+    )) +
+    ggplot2::geom_line() +
+    ggplot2::labs(
+      x = "Financial year",
+      y = "Rate"
+    ) +
+    ggplot2::scale_x_continuous(
+      breaks = x_breaks,
+      labels = x_labels,
+      guide = ggplot2::guide_axis(angle = 45)
+    )
+}

R/fct_utils.R

@@ -0,0 +1,8 @@
+#' Convert a Financial Year to Character
+#' @param year Integer. Expressed in the form `202526`. To be converted to the
+#'     form `"2025/26"`.
+enstring_fyear <- function(year) {
+  yyyy <- stringr::str_sub(year, 1, 4)
+  yy <- stringr::str_sub(year, -2)
+  paste0(yyyy, "/", yy)
+}