Support boolean project specific plugin parameters for edit in UI

Change-Id: I2a2955f3e1f158b5aa6d0f45fb5adf5ef7da6e84
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

Documentation/dev-plugins.txt

diff --git a/Documentation/dev-plugins.txt b/Documentation/dev-plugins.txt
index 16e901a..2b07cf7 100644
--- a/Documentation/dev-plugins.txt
+++ b/Documentation/dev-plugins.txt
@@ -688,9 +688,12 @@
 variable name is case-insensitive, allows only alphanumeric characters
 and '-', and must start with an alphabetic character.
 
-The example below shows how the parameter `plugin.helloworld.language`
-is bound to be editable from the WebUI. "Preferred Language" is
-provided as display name and "en" is set as default value.
+The example below shows how the parameters `plugin.helloworld.enabled`
+and `plugin.helloworld.language` are bound to be editable from the
+WebUI. For the parameter `plugin.helloworld.enabled` "Enable Greeting"
+is provided as display name and the default value is set to `true`.
+For the parameter `plugin.helloworld.language` "Preferred Language"
+is provided as display name and "en" is set as default value.
 
 [source,java]
 ----
@@ -698,6 +701,9 @@
   @Override
   protected void configure() {
     bind(ProjectConfigEntry.class)
+        .annotatedWith(Exports.named("enabled"))
+        .toInstance(new ProjectConfigEntry("Enable Greeting", true));
+    bind(ProjectConfigEntry.class)
         .annotatedWith(Exports.named("language"))
         .toInstance(new ProjectConfigEntry("Preferred Language", "en"));
   }