Add extendedVariables property

Author: David Nicklin

src/main/java/se/bjurr/gitchangelog/plugin/GitChangelogMojo.java

@@ -7,6 +7,7 @@
 import java.io.File;
 import java.util.Date;
 import java.util.List;
+import java.util.Map;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugins.annotations.Mojo;
@@ -32,6 +33,9 @@ public class GitChangelogMojo extends AbstractMojo {
   @Parameter(property = "settingsFile", required = false)
   private String settingsFile;
 
+  @Parameter(property = "extendedVariables", required = false)
+  private Map extendedVariables;
+
   @Parameter(property = "templateFile", required = false)
   private String templateFile;
 
@@ -135,6 +139,10 @@ public void execute() throws MojoExecutionException {
         builder.withSettings(new File(settingsFile).toURI().toURL());
       }
 
+      if (isSupplied(extendedVariables)) {
+        builder.withExtendedVariables(extendedVariables);
+      }
+
       if (isSupplied(toRef)) {
         builder.withToRef(toRef);
       }
@@ -254,4 +262,8 @@ public void execute() throws MojoExecutionException {
   private boolean isSupplied(String parameter) {
     return !isNullOrEmpty(parameter);
   }
+
+  private boolean isSupplied(final Map<?, ?> parameter) {
+    return parameter != null && !parameter.isEmpty();
+  }
 }