src/JobsJobsJobs/Server/Handlers.fs

@@ -218,6 +218,20 @@ open JobsJobsJobs.Data
 open JobsJobsJobs.ViewModels
 
 
+/// Handlers for /api routes
+[<RequireQualifiedAccess>]
+module Api =
+    
+    open System.IO
+
+    // POST: /api/markdown-preview
+    let markdownPreview : HttpHandler = requireUser >=> fun next ctx -> task {
+        use reader = new StreamReader (ctx.Request.Body)
+        let! preview = reader.ReadToEndAsync ()
+        return! htmlString (MarkdownString.toHtml (Text (defaultArg (Option.ofObj preview) "--"))) next ctx
+    }
+
+
 /// Handlers for /citizen routes
 [<RequireQualifiedAccess>]
 module Citizen =
@@ -768,6 +782,7 @@ let allEndpoints = [
             POST [ route "s" Listing.add ]
             PUT [ routef "/%O" Listing.update ]
         ]
+        POST [ route "/markdown-preview" Api.markdownPreview ]
         subRoute "/profile" [
             GET_HEAD [
                 route  ""               ProfileApi.current

src/JobsJobsJobs/Server/Views/Common.fs

@@ -33,14 +33,19 @@ let continentList attrs name (continents : Continent list) emptyLabel selectedVa
 let markdownEditor attrs name value editorLabel =
     div [ _class "col-12" ] [
         nav [ _class "nav nav-pills pb-1" ] [
-            button [ _type "button"; _class "jjj-md-source"; _onclick "jjj.showMarkdown('TODO')" ] [
+            button [ _type "button"; _id $"{name}EditButton"; _class "btn btn-primary btn-sm rounded-pill" ] [
                 rawText "Markdown"
-            ]; rawText "   "
-            button [ _type "button"; _class "jjj-md-preview"; _onclick "jjj.showPreview('TODO')" ] [ rawText "Preview" ]
             ]
-        section [ _id $"{name}Preview"; _class "jjj-preview"; _ariaLabel "Rendered Markdown preview" ] []
-        div [ _class "form-floating" ] [
-            textarea (List.append attrs [ _id name; _name name; _class "form-control md-edit"; _rows "10" ]) [
+            rawText "   "
+            button [ _type "button"; _id $"{name}PreviewButton"; _class "btn btn-outline-secondary btn-sm rounded-pill"
+                     _onclick $"jjj.showPreview('{name}')" ] [
+                rawText "Preview"
+            ]
+        ]
+        section [ _id $"{name}Preview"; _class "jjj-not-shown"; _ariaLabel "Rendered Markdown preview" ] []
+        div [ _id $"{name}Edit"; _class "form-floating jjj-shown" ] [
+            textarea (List.append attrs
+                                  [ _id name; _name name; _class "form-control jjj-markdown-editor"; _rows "10" ]) [
                 rawText value
             ]
             label [ _for name ] [ rawText editorLabel ]

src/JobsJobsJobs/Server/wwwroot/script.js

@@ -53,6 +53,73 @@ this.jjj = {
      } catch (_) { }
   },
 
+  /**
+   * Show a preview of the Markdown in the given editor
+   * @param {string} editorId The ID of the Markdown editor whose preview should be shown
+   */
+  async showPreview(editorId) {
+    /** @type {HTMLButtonElement} */
+    const editBtn = document.getElementById(`${editorId}EditButton`)
+    /** @type {HTMLDivElement} */
+    const editDiv = document.getElementById(`${editorId}Edit`)
+    /** @type {HTMLButtonElement} */
+    const previewBtn = document.getElementById(`${editorId}PreviewButton`)
+    /** @type {HTMLDivElement} */
+    const previewDiv = document.getElementById(`${editorId}Preview`)
+
+    editBtn.classList.remove("btn-primary")
+    editBtn.classList.add("btn-outline-secondary")
+    editBtn.addAttribute("onclick", `jjj.showEditor('{editorId}')`)
+    previewBtn.classList.remove("btn-outline-secondary")
+    previewBtn.classList.add("btn-primary")
+    previewBtn.removeAttribute("onclick")
+
+    editDiv.classList.remove("jjj-shown")
+    editDiv.classList.add("jjj-not-shown")
+    previewDiv.innerHTML = "<p><strong><em>Loading preview...</em></strong></p>"
+    previewtDiv.classList.remove("jjj-not-shown")
+    previewDiv.classList.add("jjj-shown")
+
+    const preview = await fetch("/api/markdown-preview",
+      { method: "POST", body: document.getElementById(editorId).textContent })
+    
+    let text
+    if (preview.ok) {
+      text = await preview.text()
+    } else {
+      text = `<p class="text-danger"><strong> ERROR ${preview.status}</strong> &ndash; ${preview.statusText}`
+    }
+    previewDiv.innerHTML = text
+  },
+
+  /**
+   * Show the Markdown editor (hides preview)
+   * @param {string} editorId The ID of the Markdown editor to show
+   */
+  showEditor(editorId) {
+    /** @type {HTMLButtonElement} */
+    const editBtn = document.getElementById(`${editorId}EditButton`)
+    /** @type {HTMLDivElement} */
+    const editDiv = document.getElementById(`${editorId}Edit`)
+    /** @type {HTMLButtonElement} */
+    const previewBtn = document.getElementById(`${editorId}PreviewButton`)
+    /** @type {HTMLDivElement} */
+    const previewDiv = document.getElementById(`${editorId}Preview`)
+
+    previewtBtn.classList.remove("btn-primary")
+    previewBtn.classList.add("btn-outline-secondary")
+    previewtBtn.addAttribute("onclick", `jjj.showPreview('{editorId}')`)
+    editBtn.classList.remove("btn-outline-secondary")
+    editBtn.classList.add("btn-primary")
+    editBtn.removeAttribute("onclick")
+
+    previewDiv.classList.remove("jjj-shown")
+    previewDiv.classList.add("jjj-not-shown")
+    previewDiv.innerHTML = ""
+    editDiv.classList.remove("jjj-not-shown")
+    editDiv.classList.add("jjj-shown")
+  },
+
   /**
    * Script for profile pages
    */

src/JobsJobsJobs/Server/wwwroot/style.css

@@ -199,6 +199,19 @@ span.jjj-audio-clip {
 span.jjj-audio-clip:hover {
   cursor: pointer;
 }
+/* Markdown Editor styling */
+.jjj-not-shown {
+  display: none;
+}
+.jjj-shown {
+  display: inherit;
+}
+.jjj-markdown-editor {
+  width: 100%;
+  /* When wrapping this with Bootstrap's floating label, it shrinks the input down to what a normal one-line input
+     would be; this overrides that for this textarea specifically */
+  height: inherit !important;
+}
 /* Footer styling */
 footer {
   display: flex;