Display plugin version on home page (#369)

Co-authored-by: Jan Faracik <[email protected]>

src/main/java/io/jenkins/plugins/designlibrary/Home.java

@@ -1,9 +1,11 @@
 package io.jenkins.plugins.designlibrary;
 
 import hudson.Extension;
+import hudson.PluginWrapper;
 import hudson.model.RootAction;
 import java.util.List;
 import java.util.Map;
+import jenkins.model.Jenkins;
 
 /**
  * Entry point to all the UI samples.
@@ -45,4 +47,13 @@ public UISample getDynamic(String name) {
         }
         return null;
     }
+
+    public String getPluginVersion() {
+        Jenkins jenkins = Jenkins.get();
+        PluginWrapper plugin = jenkins.getPluginManager().getPlugin("design-library");
+        if (plugin != null) {
+            return plugin.getVersion();
+        }
+        return "Version not available";
+    }
 }

src/main/resources/lib/samples/previous-next-controls.jelly

@@ -20,6 +20,14 @@
           <span>${%Home}</span>
         </a>
       </j:if>
+      <j:if test="${attrs.previousPage == null and isHome}">
+        <a href="https://github.com/jenkinsci/design-library-plugin/releases/tag/${it.pluginVersion}"
+          target="_blank"
+          class="jenkins-button jenkins-button--tertiary">
+          <l:icon src="symbol-design-library plugin-design-library" />
+          ${it.pluginVersion}
+        </a>
+      </j:if>
     </div>
     <div class="jenkins-mobile-hide">
       <j:if test="${!isHome}">