allow changing context path, by using a template for index.html

scm-webapp/src/main/java/sonia/scm/ForwardingPushStateDispatcher.java

@@ -1,27 +0,0 @@
-package sonia.scm;
-
-import sonia.scm.util.HttpUtil;
-
-import javax.servlet.RequestDispatcher;
-import javax.servlet.ServletException;
-import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpServletResponse;
-import java.io.IOException;
-
-/**
- * This dispatcher forwards every request to the index.html of the application.
- *
- * @since 2.0.0
- */
-public class ForwardingPushStateDispatcher implements PushStateDispatcher {
-  @Override
-  public void dispatch(HttpServletRequest request, HttpServletResponse response, String uri) throws IOException {
-    String path = HttpUtil.append(request.getContextPath(), "index.html");
-    RequestDispatcher dispatcher = request.getRequestDispatcher(path);
-    try {
-      dispatcher.forward(request, response);
-    } catch (ServletException e) {
-      throw new IOException("failed to forward request", e);
-    }
-  }
-}

scm-webapp/src/main/java/sonia/scm/PushStateDispatcherProvider.java

@@ -3,12 +3,13 @@ package sonia.scm;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Strings;
 
+import javax.inject.Inject;
 import javax.inject.Provider;
 
 /**
  * Injection Provider for the {@link PushStateDispatcher}. The provider will return a {@link ProxyPushStateDispatcher}
  * if the system property {@code PushStateDispatcherProvider#PROPERTY_TARGET} is set to a proxy target url, otherwise
- * a {@link ForwardingPushStateDispatcher} is used.
+ * a {@link TemplatingPushStateDispatcher} is used.
  *
  * @since 2.0.0
  */
@@ -17,11 +18,18 @@ public class PushStateDispatcherProvider implements Provider<PushStateDispatcher
   @VisibleForTesting
   static final String PROPERTY_TARGET = "sonia.scm.ui.proxy";
 
+  private Provider<TemplatingPushStateDispatcher> templatingPushStateDispatcherProvider;
+
+  @Inject
+  public PushStateDispatcherProvider(Provider<TemplatingPushStateDispatcher> templatingPushStateDispatcherProvider) {
+    this.templatingPushStateDispatcherProvider = templatingPushStateDispatcherProvider;
+  }
+
   @Override
   public PushStateDispatcher get() {
     String target = System.getProperty(PROPERTY_TARGET);
     if (Strings.isNullOrEmpty(target)) {
-      return new ForwardingPushStateDispatcher();
+      return templatingPushStateDispatcherProvider.get();
     }
     return new ProxyPushStateDispatcher(target);
   }

scm-webapp/src/main/java/sonia/scm/TemplatingPushStateDispatcher.java

@@ -0,0 +1,61 @@
+package sonia.scm;
+
+import com.google.common.annotations.VisibleForTesting;
+import sonia.scm.template.Template;
+import sonia.scm.template.TemplateEngine;
+import sonia.scm.template.TemplateEngineFactory;
+
+import javax.inject.Inject;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.io.Writer;
+
+/**
+ * This dispatcher renders the /index.mustache template, which is merged in from the scm-ui package.
+ *
+ * @since 2.0.0
+ */
+public class TemplatingPushStateDispatcher implements PushStateDispatcher {
+
+  @VisibleForTesting
+  static final String TEMPLATE = "/index.mustache";
+
+  private final TemplateEngine templateEngine;
+
+  @Inject
+  public TemplatingPushStateDispatcher(TemplateEngineFactory templateEngineFactory) {
+    this(templateEngineFactory.getDefaultEngine());
+  }
+
+  @VisibleForTesting
+  TemplatingPushStateDispatcher(TemplateEngine templateEngine) {
+    this.templateEngine = templateEngine;
+  }
+
+  @Override
+  public void dispatch(HttpServletRequest request, HttpServletResponse response, String uri) throws IOException {
+    response.setContentType("text/html");
+    response.setCharacterEncoding("UTF-8");
+
+    Template template = templateEngine.getTemplate(TEMPLATE);
+    try (Writer writer = response.getWriter()) {
+      template.execute(writer, new IndexHtmlModel(request));
+    }
+  }
+
+  @VisibleForTesting
+  static class IndexHtmlModel {
+
+    private final HttpServletRequest request;
+
+    private IndexHtmlModel(HttpServletRequest request) {
+      this.request = request;
+    }
+
+    public String getContextPath() {
+      return request.getContextPath();
+    }
+
+  }
+}