From ee880217bcec34edc42e256ab02f04bcf531d10f Mon Sep 17 00:00:00 2001
From: Remko Popma <remkop@yahoo.com>
Date: Mon, 2 Jul 2018 20:42:34 +0900
Subject: [PATCH] #322 update user manual for `defaultValue` attribute

Closes #322
---
 docs/index.adoc             | 33 ++++++++++++++++++++++++++++++++-
 src/main/java/overview.html |  2 +-
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/docs/index.adoc b/docs/index.adoc
index aa02640a3..cb9cab0b1 100644
--- a/docs/index.adoc
+++ b/docs/index.adoc
@@ -552,6 +552,37 @@ class TypeDemo {
 }
 ----
 
+== Default Values
+It is possible to define a default value for an option or positional parameter, that is assigned when the user did not specify this option or positional parameter on the command line.
+
+For annotated fields, it is simplest to declare the field with a value:
+[source,java]
+----
+@Option(names = "-c", description = "The count (default: ${DEFAULT_VALUE})")
+int count = 123; // default value is 123
+----
+For <<Annotated Methods,annotated methods>>, use the `defaultValue` annotation attribute. For example, for an annotated interface:
+[source,java]
+----
+interface Spec {
+    @Option(names = "-c", defaultValue = "123", description = "... ${DEFAULT_VALUE} ...")
+    int count();
+}
+----
+Or similarly for an annotated concrete class:
+[source,java]
+----
+class Impl {
+    int count;
+
+    @Option(names = "-c", defaultValue = "123", description = "... ${DEFAULT_VALUE} ...")
+    void setCount(int count) {
+        this.count = count;
+    }
+}
+----
+
+Note that you can use the `${DEFAULT_VALUE}` variable in the `description` of the option or positional parameter and picocli will <<Show Default Values,show>> the actual default value.
 
 == Multiple Values
 Multi-valued options and positional parameters are annotated fields that can capture multiple values from the command line.
@@ -1396,7 +1427,7 @@ Usage: <main class> <host> <port> [<files>...]
 
 === Show Default Values
 ==== `${DEFAULT-VALUE}` Variable
-From picocli 3.2, it is possible to embed the default values in the description for an option or positional parameter by
+From picocli 3.2, it is possible to embed the <<Default Values,default values>> in the description for an option or positional parameter by
 specifying the variable `${DEFAULT-VALUE}` in the description text.
 Picocli uses reflection to get the default values from the annotated fields.
 
diff --git a/src/main/java/overview.html b/src/main/java/overview.html
index b2265a936..77a69572a 100644
--- a/src/main/java/overview.html
+++ b/src/main/java/overview.html
@@ -35,7 +35,7 @@
     public static void main(String[] args) throws Exception {
         // CheckSum implements Callable, so parsing, error handling and handling user
         // requests for usage help or version help can be done with one line of code.
-        CommandLine.call(new CheckSum(), System.err, args);
+        CommandLine.call(new CheckSum(), args);
     }
 
     &#064;Override