Support for IDefaultProvider

4 files changed, 88 insertions, 4 deletions

diff --git a/src/main/java/com/beust/jcommander/IDefaultProvider.java b/src/main/java/com/beust/jcommander/IDefaultProvider.java
new file mode 100644
index 0000000..5ea0bc1
--- /dev/null
+++ b/src/main/java/com/beust/jcommander/IDefaultProvider.java
@@ -0,0 +1,17 @@
+package com.beust.jcommander;
+
+/**
+ * Allows the specification of default values.
+ * 
+ * @author cbeust
+ */
+public interface IDefaultProvider {
+
+  /**
+   * @param optionName The name of the option as specified in the names() attribute
+   * of the @Parameter option (e.g. "-file").
+   * 
+   * @return the default value for this option.
+   */
+  String getDefaultValueFor(String optionName);
+}
diff --git a/src/main/java/com/beust/jcommander/JCommander.java b/src/main/java/com/beust/jcommander/JCommander.java
index b32e293..7c95d32 100644
--- a/src/main/java/com/beust/jcommander/JCommander.java
+++ b/src/main/java/com/beust/jcommander/JCommander.java
@@ -74,6 +74,8 @@ public class JCommander {
 
   private ResourceBundle m_bundle;
 
+  private IDefaultProvider m_defaultProvider;
+
   public JCommander(Object object) {
     init(object, null);
   }
@@ -189,7 +191,7 @@ public class JCommander {
         }
       }
     }
-    throw new ParameterException("Couldn't find a description for " + arg);
+    throw new ParameterException("Unknown parameter: " + arg);
   }
 
   private String getSeparatorFor(String arg) {
@@ -206,7 +208,7 @@ public class JCommander {
    * @param fileName the command line filename
    * @return the file content as a string.
    */
-  public static List<String> readFile(String fileName) {
+  private static List<String> readFile(String fileName) {
     List<String> result = Lists.newArrayList();
 
     try {
@@ -274,6 +276,7 @@ public class JCommander {
               ParameterDescription pd = new ParameterDescription(object, p, f, m_bundle);
               m_fields.put(f, pd);
               m_descriptions.put(name, pd);
+
               if (p.required()) m_requiredFields.put(f, pd);
             }
           }
@@ -282,6 +285,15 @@ public class JCommander {
     }
   }
 
+  private void initializeDefaultValue(ParameterDescription pd) {
+    String optionName = pd.getParameter().names()[0];
+    String def = m_defaultProvider.getDefaultValueFor(optionName);
+    if (def != null) {
+      p("Initializing " + optionName + " with default value:" + def);
+      pd.addValue(def);
+    }
+  }
+
   /**
    * Main method that parses the values and initializes the fields accordingly.
    */
@@ -427,5 +439,17 @@ public class JCommander {
       System.out.println("[JCommander] " + string);
     }
   }
+
+  /**
+   * Define the default provider for this instance.
+   */
+  public void setDefaultProvider(IDefaultProvider defaultProvider) {
+    m_defaultProvider = defaultProvider;
+    if (m_defaultProvider != null) {
+      for (ParameterDescription pd : m_descriptions.values()) {
+        initializeDefaultValue(pd);
+      }
+    }
+  }
 }
 
diff --git a/src/test/java/com/beust/jcommander/ArgsDefault.java b/src/test/java/com/beust/jcommander/ArgsDefault.java
new file mode 100644
index 0000000..60fd553
--- /dev/null
+++ b/src/test/java/com/beust/jcommander/ArgsDefault.java
@@ -0,0 +1,23 @@
+package com.beust.jcommander;
+
+import org.testng.collections.Lists;
+
+import java.util.List;
+
+public class ArgsDefault {
+  @Parameter
+  public List<String> parameters = Lists.newArrayList();
+
+  @Parameter(names = "-log", description = "Level of verbosity")
+  public Integer log = 1;
+
+  @Parameter(names = "-groups", description = "Comma-separated list of group names to be run")
+  public String groups;
+
+  @Parameter(names = "-debug", description = "Debug mode")
+  public boolean debug = false;
+
+  @Parameter(names = "-long", description = "A long number")
+  public long l;
+
+}
diff --git a/src/test/java/com/beust/jcommander/JCommanderTest.java b/src/test/java/com/beust/jcommander/JCommanderTest.java
index 81e53c0..9d6bb83 100644
--- a/src/test/java/com/beust/jcommander/JCommanderTest.java
+++ b/src/test/java/com/beust/jcommander/JCommanderTest.java
@@ -252,13 +252,33 @@ public class JCommanderTest {
     };
   }
 
+  @Test
+  public void defaultProvider1() {
+    ArgsDefault a = new ArgsDefault();
+    JCommander jc = new JCommander(a);
+    jc.setDefaultProvider(new IDefaultProvider() {
+
+      @Override
+      public String getDefaultValueFor(String optionName) {
+        return "-debug".equals(optionName) ? "false" : "42";
+      }
+      
+    });
+
+    jc.parse("f");
+
+    Assert.assertEquals(a.groups, "42");
+    Assert.assertEquals(a.l, 42);
+    Assert.assertEquals(a.log.intValue(), 42);
+  }
+
   public static void main(String[] args) {
 //    for (Object[] p : f()) {
 //      int tc = JCommander.getTabCount((Integer) p[0], (Integer) p[1]);
 //      Assert.assertEquals(tc, ((Integer) p[2]).intValue());
 //    }
-//    new JCommanderTest().formatting();
-    new JCommander(new CommandLineArgs2()).usage();
+    new JCommanderTest().defaultProvider1();
+//    new JCommander(new CommandLineArgs2()).usage();
 //    Separator a = new Separator();
 //    String[] argv = new String[] { "-n", "foo" };
 //    String[] argv = new String[] { "-v", "t" };