feat: error handling

devOpifex · Mar 9, 2024 · d046f29 · d046f29
1 parent cb9321a
commit d046f29
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Showing 11 changed files with 100 additions and 7 deletions.
diff --git a/DESCRIPTION b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: communicate
 Title: Communicate Between 'Shiny' Client and Server
-Version: 0.1.2.9001
+Version: 0.1.3.9000
 Authors@R: 
   c(
     person(given = "John",
@@ -15,7 +15,7 @@ Description: What the package does (one paragraph).
 License: GPL (>= 3)
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.2.3
+RoxygenNote: 7.3.0
 Imports:
   shiny,
   jsonlite,

diff --git a/NAMESPACE b/NAMESPACE
@@ -2,6 +2,7 @@
 
 S3method(print,converters_fn)
 S3method(print,defaults_fn)
+S3method(print,errors_fn)
 export(Character)
 export(Dataframe)
 export(Date)

diff --git a/R/aaa.R b/R/aaa.R
@@ -6,3 +6,4 @@ env$prefix <- NULL
 env$handlers <- list()
 env$schemas <- list()
 env$defaults <- list()
+env$errors <- list()
diff --git a/R/core.R b/R/core.R
@@ -47,7 +47,23 @@ com <- \(id, handler) {
       # defaults may be reactives
       check_args_match(env$handlers[[id]], ...)
       env$defaults[[id]] <- list(...)
-      com_send(id)
+
+      on.exit(
+        com_send(id),
+        add = TRUE
+      )
+
+      fn <- \(handler, ...){
+        if(!is.function(handler))
+          stop("Handler must be a function")
+
+        if(length(methods::formalArgs(handler)) < 1L)
+          stop("Handler must have at least one argument")
+
+        env$errors[[id]] <- handler
+      } |>
+        construct_errors_fn() |>
+        invisible()
     } 
 
     fn |>
@@ -82,6 +98,15 @@ construct_converters_fn <- \(fn) {
   )
 }
 
+#' @rdname constructors
+#' @keywords internal
+construct_errors_fn <- \(fn) {
+  structure(
+    fn,
+    class = c("errors_fn", class(fn))
+  )
+}
+
 #' @export
 print.defaults_fn <- \(x, ...) {
   cat("Add defaults, e.g.: (x = 1)\n")
@@ -92,6 +117,11 @@ print.converters_fn <- \(x, ...) {
   cat("Add converters, e.g.: (x = as_dataframe)\n")
 }
 
+#' @export
+print.errors_fn <- \(x, ...) {
+  cat("Add error handlers, e.g.: (error_handler_fn)\n")
+}
+
 #' Communicate
 #' 
 #' Serve communication channels.
@@ -124,6 +154,10 @@ com_serve <- \(session = shiny::getDefaultReactiveDomain()) {
             error = results$message,
             id = results$id
           )
+
+          if(env$errors[[name]]){
+            env$errors[[name]](results)
+          }
         }
 
         http_response_json(results, status)
@@ -164,6 +198,10 @@ com_send <- \(name, session = shiny::getDefaultReactiveDomain()) {
     status <- 200L
     if(inherits(results, "error")) {
       status <- 400L
+      if(length(env$errors[[name]])){
+        env$errors[[name]](results)
+      }
+
       results <- list(
         error = results$message,
         id = results$id

diff --git a/README.md b/README.md
@@ -5,6 +5,8 @@
 Small framework to communicate between Shiny client and server via HTTP requests.
 Run `communicate::example()` for a short demo.
 
+[Site](https://communicate.opifex.org/)
+
 </div>
 
 ## Installation

diff --git a/docs/_coverpage.md b/docs/_coverpage.md
@@ -9,4 +9,4 @@
 [GitHub](https://github.com/devOpifex/communicate)
 [Get Started](/r)
 
-![color](#3f3f3f)
+![color](#fff)
diff --git a/docs/index.html b/docs/index.html
@@ -6,7 +6,10 @@
   <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
   <meta name="description" content="Description">
   <meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0">
-  <link rel="stylesheet" href="//cdn.jsdelivr.net/npm/docsify@4/lib/themes/dark.css">
+  <link
+    rel="stylesheet"
+    href="//cdn.jsdelivr.net/npm/docsify@4/themes/vue.css"
+  />
 </head>
 <body>
   <div id="app"></div>

diff --git a/docs/js.md b/docs/js.md
@@ -21,6 +21,8 @@ packer::npm_install("@devopifex/communicate")
 Ideally you'd want to catch errors as shown below,
 where the callback fails because there is no default for `x`.
 
+See the R Package page to see how to handle errors R-side.
+
 ```r
 library(shiny)
 library(communicate)

diff --git a/docs/r.md b/docs/r.md
@@ -143,3 +143,46 @@ server <- \(input, output, session){
 
 shinyApp(ui, server)
 ```
+
+## Error handling
+
+Finally, you can pass an error handler.
+
+Note that the code below purposely fails.
+
+```r
+library(shiny)
+library(communicate)
+
+add <- \(x, y){
+  x + y + "error" # this will cause an error
+} 
+
+err <- \(error){
+  cat("Aaaaah, an error!\n")
+  print(error)
+}
+
+# more on JavaScript error handling in the JavaScript page
+script <- "
+  $('#btn').on('click', () => {
+    communicate.com('add', {x: 1})
+      .then(res => alert(`equals: ${res}`))
+      .catch(error => alert('There was an error')); # catch error
+  })
+"
+
+ui <- fluidPage(
+  # import dependencies
+  useCommunicate(),
+  h1("Hello"),
+  tags$a("Communicate", id = "btn"),
+  tags$script(HTML(script))
+)
+
+server <- \(input, output, session){
+  com("add", add)(x = Integer, y = Numeric)(y = 1.1)(err)
+}
+
+shinyApp(ui, server)
+```
diff --git a/man/constructors.Rd b/man/constructors.Rd
diff --git a/srcjs/index.ts b/srcjs/index.ts
@@ -35,7 +35,7 @@ window.Shiny.addCustomMessageHandler(
   },
 );
 
-async function com(id: string, args) {
+async function com(id: string, args: any) {
   if (!id) {
     throw new Error("No id provided");
   }
@@ -125,7 +125,7 @@ function makeQuery(id: string, args: any): string {
   return argNames
     .map((argName) => {
       let arg = args[argName];
-      const valid = valids.find((valid) => valid.name === argName);
+      const valid = valids.find((valid: any) => valid.name === argName);
 
       if (!valid) {
         throw new Error(