feat: use local demo sources in development mode

src/main/java/com/flowingcode/vaadin/addons/DevSourceRequestHandler.java

@@ -0,0 +1,51 @@
+package com.flowingcode.vaadin.addons;
+
+import com.vaadin.flow.server.RequestHandler;
+import com.vaadin.flow.server.VaadinRequest;
+import com.vaadin.flow.server.VaadinResponse;
+import com.vaadin.flow.server.VaadinService;
+import com.vaadin.flow.server.VaadinSession;
+import java.io.File;
+import java.io.IOException;
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.IOUtils;
+
+public class DevSourceRequestHandler implements RequestHandler {
+
+  private static final int SC_OK = 200;
+
+  private static final int SC_NOT_FOUND = 404;
+
+  @Override
+  public boolean handleRequest(VaadinSession session, VaadinRequest request,
+      VaadinResponse response) throws IOException {
+
+    if (VaadinService.getCurrent().getDeploymentConfiguration().isProductionMode()) {
+      return false;
+    }
+
+    String path = request.getPathInfo();
+    if (!path.startsWith("/src/")) {
+      return false;
+    }
+
+    if (fileExists(path)) {
+      byte file[] = FileUtils.readFileToByteArray(getFile(path));
+      response.setStatus(SC_OK);
+      IOUtils.write(file, response.getOutputStream());
+    } else {
+      response.setStatus(SC_NOT_FOUND);
+    }
+
+    return true;
+  }
+
+  public static boolean fileExists(String path) {
+    return getFile(path).exists();
+  }
+
+  private static File getFile(String path) {
+    return new File(path.substring(1));
+  }
+
+}

src/main/java/com/flowingcode/vaadin/addons/DevSourceRequestHandlerInitializer.java

@@ -0,0 +1,15 @@
+package com.flowingcode.vaadin.addons;
+
+import com.vaadin.flow.server.ServiceInitEvent;
+import com.vaadin.flow.server.VaadinServiceInitListener;
+
+public class DevSourceRequestHandlerInitializer implements VaadinServiceInitListener {
+
+  @Override
+  public void serviceInit(ServiceInitEvent event) {
+    if (!event.getSource().getDeploymentConfiguration().isProductionMode()) {
+      event.addRequestHandler(new DevSourceRequestHandler());
+    }
+  }
+
+}

src/main/java/com/flowingcode/vaadin/addons/demo/SourceCodeView.java

@@ -19,11 +19,13 @@
  */
 package com.flowingcode.vaadin.addons.demo;
 
+import com.flowingcode.vaadin.addons.DevSourceRequestHandler;
 import com.vaadin.flow.component.HasSize;
 import com.vaadin.flow.component.dependency.JsModule;
 import com.vaadin.flow.component.dependency.NpmPackage;
 import com.vaadin.flow.component.html.Div;
 import com.vaadin.flow.dom.Element;
+import com.vaadin.flow.server.VaadinService;
 
 @SuppressWarnings("serial")
 @JsModule("./code-viewer.ts")
@@ -43,6 +45,13 @@ public SourceCodeView(String sourceUrl) {
   }
 
   private static String translateSource(String url) {
+    if (!VaadinService.getCurrent().getDeploymentConfiguration().isProductionMode()) {
+      String src = url.replaceFirst("^.*/src/", "/src/");
+      if (DevSourceRequestHandler.fileExists(src)) {
+        return src;
+      }
+    }
+
     if (url.startsWith("https://github.com")) {
       url = url.replaceFirst("github.com", "raw.githubusercontent.com");
       url = url.replaceFirst("/blob", "");

src/main/resources/META-INF/services/com.vaadin.flow.server.VaadinServiceInitListener

@@ -0,0 +1 @@
+com.flowingcode.vaadin.addons.DevSourceRequestHandlerInitializer