Added required subcommand

CHANGELOG.md

@@ -1,3 +1,7 @@
+## Version 0.5 (in progress)
+
+* Added `require_subcommand` to `App`, to simplify forcing subcommands. Do not "chain" with `add_subcommand`, since that is the subcommand, not the master `App`. Untested.
+
 ## Version 0.4
 
 * Updates to help print

include/CLI/App.hpp

@@ -47,6 +47,7 @@ protected:
     std::vector<App_p> subcommands;
     bool parsed {false};
     App* subcommand {nullptr};
+    bool required_subcommand = false;
     std::string progname {"program"};
     Option* help_flag {nullptr};
 
@@ -117,7 +118,6 @@ public:
         return subcommands.back().get();
     }
 
-
     /// Add an option, will automatically understand the type for common types.
     /** To use, create a variable with the expected type, and pass it in after the name.
      * After start is called, you can use count to see if the value was passed, and
@@ -332,6 +332,7 @@ public:
     }
 
     /// This allows subclasses to inject code before callbacks but after parse
+    /// This does not run if any errors or help is thrown.
     virtual void pre_callback() {}
 
     /// Parses the command line - throws errors
@@ -411,8 +412,12 @@ public:
                     pos=true;
             }
 
-        if(subcommands.size() > 0)
+        if(subcommands.size() > 0) {
-            out << " [SUBCOMMANDS]";
+            if(required_subcommand)
+                out << " SUBCOMMAND";
+            else
+                out << " [SUBCOMMAND]";
+        }
 
         out << std::endl << std::endl;
 
@@ -459,6 +464,10 @@ public:
         return name;
     }
 
+    /// Require a subcommand to be given (does not affect help call)
+    void require_subcommand(bool value = true) {
+        required_subcommand = value;
+    }
 
 protected:
 
@@ -579,6 +588,9 @@ protected:
                     throw ExcludesError(opt->get_name(), opt_ex->get_name());
         }
 
+        if(required_subcommand && subcommand == nullptr)
+            throw RequiredError("Subcommand required");
+
         if(positionals.size()>0)
             throw PositionalError("[" + detail::join(positionals) + "]");