gh 19 improve landing page experience

.gitignore

@@ -45,3 +45,6 @@ notebook-profile-*
 ### pom release artefacts
 release.properties
 pom.xml.releaseBackup
+
+# template classes generated by jte
+jte-classes/

jnotebook-core/src/main/java/tech/catheu/jnotebook/InteractiveNotebook.java

@@ -8,7 +8,10 @@
 package tech.catheu.jnotebook;
 
 import io.methvin.watcher.DirectoryChangeEvent;
+import io.methvin.watcher.hashing.FileHash;
 import io.reactivex.rxjava3.core.Observable;
+import io.reactivex.rxjava3.subjects.PublishSubject;
+import org.checkerframework.checker.nullness.qual.NonNull;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import tech.catheu.jnotebook.evaluate.GreedyInterpreter;
@@ -32,36 +35,38 @@ public class InteractiveNotebook {
 
   private static final Logger LOG = LoggerFactory.getLogger(InteractiveNotebook.class);
 
-  private static final String RESOURCES_HELLO_WORLD_NOTEBOOK = "/jnb_interactive/hello_world.jsh";
+  private static final String RESOURCES_HELLO_WORLD_NOTEBOOK =
+          "/jnb_interactive/hello_world.jsh";
   private static final String FILESYSTEM_HELLO_WORLD_NAME = "hello_world.jsh";
 
   private final Main.InteractiveConfiguration configuration;
   private static final String JSHELL_SUFFIX = ".jsh";
   private final StaticParser staticParser;
   private final Interpreter interpreter;
   private final Renderer renderer;
-  private final InteractiveServer server;
+  private InteractiveServer server;
 
   public InteractiveNotebook(final Main.InteractiveConfiguration configuration) {
     this.configuration = configuration;
     final ShellProvider shellProvider = new ShellProvider(configuration);
     this.staticParser = new StaticParser(shellProvider);
     this.interpreter = new GreedyInterpreter(shellProvider);
     this.renderer = new Renderer(configuration);
-    this.server = new InteractiveServer(configuration);
   }
 
   public void run() throws IOException {
     prepare();
-    server.start();
-    final Observable<DirectoryChangeEvent> notebookEvents =
+    final Observable<DirectoryChangeEvent> fileChangeEvents =
             PathObservables.of(Paths.get(configuration.notebookPath))
                            .filter(e -> e.path().toString().endsWith(JSHELL_SUFFIX));
-    //.subscribe(s -> server.sendReload()); to subscribe on a side scheduler
-
+    final PublishSubject<DirectoryChangeEvent> manualTriggers = PublishSubject.create();
+    this.server = new InteractiveServer(configuration,
+                                        path -> manualTriggers.onNext(
+                                                directoryChangeEvent(path)));
+    server.start();
     LOG.info("Notebook server started. Go to http://localhost:" + configuration.port);
-
-    notebookEvents
+    manualTriggers
+            .mergeWith(fileChangeEvents)
             .doOnEach(e -> server.sendStatus(NotebookServerStatus.COMPUTE))
             .map(staticParser::staticSnippets)
             .doOnError(InteractiveNotebook::logError)
@@ -72,6 +77,17 @@ public void run() throws IOException {
             .subscribe(server::sendUpdate, InteractiveNotebook::logError);
   }
 
+  @NonNull
+  private static DirectoryChangeEvent directoryChangeEvent(final Path path) {
+    return new DirectoryChangeEvent(
+            DirectoryChangeEvent.EventType.MODIFY,
+            false,
+            path,
+            FileHash.fromLong(0),
+            0,
+            path.getRoot());
+  }
+
   private void prepare() {
     // ensure notebook folder exists, if not, create it.
     final Path notebooksFolder = Paths.get(configuration.notebookPath);
@@ -91,7 +107,9 @@ private static void logError(Throwable e) {
 
 
   public void stop() throws IOException {
-    server.stop();
+    if (server != null) {
+      server.stop();
+    }
     staticParser.stop();
     interpreter.stop();
     renderer.stop();

jnotebook-core/src/main/java/tech/catheu/jnotebook/NotebookRenderer.java

@@ -75,13 +75,15 @@ public void render(final Main.RenderConfiguration config) {
       final Interpreted interpreted = interpreter.interpret(staticParsing);
       final Rendering render = renderer.render(interpreted);
       final HtmlTemplateEngine templateEngine = new HtmlTemplateEngine();
-      String html = templateEngine.render(config, false, render.html());
+      final HtmlTemplateEngine.TemplateData model =
+              new HtmlTemplateEngine.TemplateData(config, false, render.html(), null);
+      String html = templateEngine.render(model);
       if (!config.noOptimize) {
         html = optimizeHtml(html);
       }
 
-      final String outputPath = optional(config.outputPath)
-              .orElse(Files.getNameWithoutExtension(config.inputPath) + ".html");
+      final String outputPath =
+              optional(config.outputPath).orElse(Files.getNameWithoutExtension(config.inputPath) + ".html");
       final File outputFile = FileUtils.getFile(outputPath);
       FileUtils.write(outputFile, html, StandardCharsets.UTF_8);
       LOG.info("Notebook rendered successfully and written to {}", outputFile);
@@ -139,7 +141,8 @@ public void handle(HttpExchange exchange) throws IOException {
           responseStream.close();
         }
       });
-      final HtmlFileServer result = new HtmlFileServer("http://localhost:" + port, server);
+      final HtmlFileServer result =
+              new HtmlFileServer("http://localhost:" + port, server);
       return result;
     } catch (Exception e) {
       LOG.error("Failed to create a server: ", e);

jnotebook-core/src/main/java/tech/catheu/jnotebook/server/HtmlTemplateEngine.java

@@ -19,6 +19,7 @@
 import tech.catheu.jnotebook.utils.JavaUtils;
 
 import java.nio.file.Path;
+import java.util.List;
 
 public class HtmlTemplateEngine {
 
@@ -36,15 +37,13 @@ public HtmlTemplateEngine() {
   }
 
   // render is the generated notebook html
-  public String render(final Main.SharedConfiguration config, final boolean interactive,
-                       final String render) {
-    final TemplateModel model =  new TemplateModel(config, interactive, render);
+  public String render(TemplateData model) {
     final TemplateOutput output = new StringOutput();
     delegate.render("index.jte", model, output);
     return output.toString();
   }
 
-  public record TemplateModel(Main.SharedConfiguration config, boolean interactive, String render) {}
+  public record TemplateData(Main.SharedConfiguration config, boolean interactive, String render, List<Path> notebooksInPath) {}
 
 
 }

jnotebook-core/src/main/java/tech/catheu/jnotebook/server/InteractiveServer.java

@@ -15,6 +15,8 @@
 import io.undertow.util.Headers;
 import io.undertow.websockets.WebSocketConnectionCallback;
 import io.undertow.websockets.WebSocketProtocolHandshakeHandler;
+import io.undertow.websockets.core.AbstractReceiveListener;
+import io.undertow.websockets.core.BufferedTextMessage;
 import io.undertow.websockets.core.WebSocketChannel;
 import io.undertow.websockets.core.WebSockets;
 import io.undertow.websockets.spi.WebSocketHttpExchange;
@@ -28,22 +30,30 @@
 import tech.catheu.jnotebook.render.Rendering;
 
 import java.io.IOException;
-import java.util.ArrayList;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.List;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.function.Consumer;
+import java.util.stream.Stream;
 
 public class InteractiveServer {
 
-  private static final Logger LOG = LoggerFactory.getLogger(Main.class);
+  private static final Logger LOG = LoggerFactory.getLogger(InteractiveServer.class);
 
   private final Main.InteractiveConfiguration configuration;
+  private final Consumer<Path> renderTrigger;
 
   private Undertow server;
-  private final List<WebSocketChannel> channels = new ArrayList<>();
+  private final Queue<WebSocketChannel> channels = new ConcurrentLinkedQueue<>();
   XnioWorker worker;
   private Rendering lastUpdate;
 
-  public InteractiveServer(final Main.InteractiveConfiguration configuration) {
+  public InteractiveServer(final Main.InteractiveConfiguration configuration,
+                           Consumer<Path> renderTrigger) {
     this.configuration = configuration;
+    this.renderTrigger = renderTrigger;
   }
 
 
@@ -94,7 +104,20 @@ private static class TemplatedHttpHandler implements HttpHandler {
 
     @Override
     public void handleRequest(HttpServerExchange exchange) throws Exception {
-      final String html = templateEngine.render(this.configuration, true, null);
+      final List<Path> notebooksInPath;
+      try (Stream<Path> files = Files.find(Path.of(configuration.notebookPath),
+                                           10,
+                                           (path, attributes) -> attributes.isRegularFile() && path.toString()
+                                                                                                   .endsWith(
+                                                                                                           ".jsh"))) {
+        notebooksInPath = files.toList();
+      }
+      final HtmlTemplateEngine.TemplateData model = new HtmlTemplateEngine.TemplateData(
+              this.configuration,
+              true,
+              null,
+              notebooksInPath);
+      final String html = templateEngine.render(model);
       exchange.getResponseHeaders().put(Headers.CONTENT_TYPE, "text/html");
       exchange.getResponseSender().send(html);
     }
@@ -119,7 +142,8 @@ private void sendMessage(final String message) {
       }
     }
     if (!messageSent) {
-      LOG.error("ERROR: trying to send updates but no client is opened. Go to http://localhost:" + configuration.port);
+      LOG.error(
+              "ERROR: trying to send updates but no client is opened. Go to http://localhost:" + configuration.port);
     }
   }
 
@@ -144,10 +168,29 @@ public void onConnect(WebSocketHttpExchange webSocketHttpExchange,
       channels.add(channel);
       // resend to every channel - not very correct but simpler for the moment
       sendStatus(NotebookServerStatus.CONNECTED);
+      setupReceiver(channel);
       if (lastUpdate != null) {
         // resend to every channel - not necessary but simpler for the moment
         sendUpdate(lastUpdate);
       }
     }
+
+    private void setupReceiver(WebSocketChannel channel) {
+      channel.getReceiveSetter().set(new AbstractReceiveListener() {
+        @Override
+        protected void onFullTextMessage(WebSocketChannel channel,
+                                         BufferedTextMessage message) throws IOException {
+          final String messageText = message.getData();
+          if (messageText.startsWith("refresh_")) {
+            final String substring = messageText.substring(8);
+            LOG.info("Triggering refresh for file {}", substring);
+            renderTrigger.accept(Path.of(substring));
+          } else {
+            LOG.error("Received unsupported message from websocket: {}", messageText);
+          }
+        }
+      });
+      channel.resumeReceives();
+    }
   }
 }

jnotebook-core/src/main/jte/index.jte

@@ -1,7 +1,8 @@
 @import tech.catheu.jnotebook.Main.InteractiveConfiguration
-@import tech.catheu.jnotebook.server.HtmlTemplateEngine.TemplateModel
+@import tech.catheu.jnotebook.server.HtmlTemplateEngine.TemplateData
+@import java.nio.file.Path
 @import java.util.Optional
-@param TemplateModel model
+@param TemplateData model
 <!--/*
 
     Copyright 2023 Cyril de Catheu
@@ -646,7 +647,9 @@
             background-color: #ffe4e4;
         }
 
-        [x-cloak] { display: none !important; }
+        [x-cloak] {
+            display: none !important;
+        }
     </style>
 
     <script defer class="jnb-no-opti" src="https://cdn.jsdelivr.net/npm/[email protected]/dist/cdn.min.js"></script>
@@ -670,7 +673,7 @@
 </head>
 <body>
 <div x-cloak x-data="{ tocOpen: window.innerWidth >= 768, notebookStatus: 'Connected'}" class="flex">
-    <button x-on:click="tocOpen = ! tocOpen"
+    <button x-on:click="tocOpen=!tocOpen"
             class="toc-toggle z-20 fixed right-2 top-2 md:right-auto md:left-3 md:top-[7px] text-slate-400 font-sans text-xs hover:underline cursor-pointer flex items-center bg-white py-1 px-3 md:p-0 rounded-full md:rounded-none border md:border-0 border-slate-200 shadow md:shadow-none">
         <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke="currentColor" width="20"
              height="20">
@@ -687,7 +690,7 @@
         <div class="px-3 mb-1 mt-1 md:mt-0 text-xs md:text-[12px] uppercase tracking-wider text-slate-500 font-medium px-3 mb-1 leading-none">
             ToC
         </div>
-        <div x-on:click="tocOpen = ! tocOpen"
+        <div x-on:click="tocOpen=!tocOpen"
              class="toc-toggle text-slate-500 absolute right-2 top-[11px] cursor-pointer z-10">
             <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke="currentColor"
                  stroke-width="2" class="w-4 w-4">
@@ -697,23 +700,13 @@
         <div id="toc"></div>
     </aside>
     <div x-bind:class="tocOpen ? 'toc-offset' : ''" class="flex-auto h-screen overflow-y-auto scroll-container">
-        @if(model.render() != null)
-            <div id="notebook" class="flex flex-col items-center viewer-notebook flex-auto">
+        <div id="notebook" class="flex flex-col items-center viewer-notebook flex-auto">
+            @if(model.render() != null)
                 $unsafe{model.render()}
-            </div>
-        @else
-            <div id="notebook" class="flex flex-col items-center viewer-notebook flex-auto">
-                <div id="helper" class="viewer viewer-result w-full max-w-prose px-8">
-                    <div class="relative">
-                        <div class="overflow-y-hidden">
-                            <p>Welcome to <code>jnotebook</code>. Learn more on <a href="https://jnotebook.catheu.tech">jnotebook.catheu.tech</a>.
-                            </p>
-                            <p>Edit a <code>.jsh</code> file in your <code>${((InteractiveConfiguration) model.config()).notebookPath}</code> folder to
-                                make your notebook appear.</p></div>
-                    </div>
-                </div>
-            </div>
-        @endif
+            @else
+                @template.landing(model=model)
+            @endif
+        </div>
     </div>
     @if(model.interactive())
         <script defer>
@@ -761,6 +754,12 @@
                         update(socketEvent.data);
                     }
                 };
+
+                // something like this for the message passing
+                const textAreas = document.querySelectorAll("button.notebook-in-path")
+                    .forEach(e => e.addEventListener('click', ev => {
+                        socket.send("refresh_" + e.textContent)
+                    }));
             }
 
             const port = "${Optional.ofNullable(((InteractiveConfiguration) model.config()).port).orElse(5002)}";

jnotebook-core/src/main/jte/landing.jte

@@ -0,0 +1,34 @@
+@import tech.catheu.jnotebook.Main.InteractiveConfiguration
+@param tech.catheu.jnotebook.server.HtmlTemplateEngine.TemplateData model
+
+<div id="helper" class="viewer viewer-result w-full max-w-prose px-8">
+    <div class="relative">
+        <div class="overflow-y-hidden">
+            <p>Welcome to <code>jnotebook</code>. Learn more on <a href="https://jnotebook.catheu.tech">jnotebook.catheu.tech</a>.
+            </p>
+            <p>Edit a <code>.jsh</code> file in your
+                <code>${((InteractiveConfiguration) model.config()).notebookPath}</code> folder to
+                launch your notebook, or click on a notebook below.</p>
+            <div>
+                <table>
+                    <tr>
+                        <td>Notebooks</td>
+                    </tr>
+                    @if(model.notebooksInPath() == null || model.notebooksInPath().isEmpty())
+                        <tr>
+                            <td>
+                                <i>There are no notebooks in the <code>${((InteractiveConfiguration) model.config()).notebookPath}</code> folder.</i>
+                            </td>
+                        </tr>
+                    @else
+                        @for(final java.nio.file.Path p: model.notebooksInPath())
+                            <tr>
+                                <td><button class="notebook-in-path"><a>${p.toString()}</a></button></td>
+                            </tr>
+                        @endfor
+                    @endif
+                </table>
+            </div>
+        </div>
+    </div>
+</div>