Updated documentation

1 files changed, 14 insertions, 0 deletions

diff --git a/cmd2/argparse_custom.py b/cmd2/argparse_custom.py
index 5071989d..59a00f4c 100644
--- a/cmd2/argparse_custom.py
+++ b/cmd2/argparse_custom.py
@@ -102,6 +102,20 @@ Tab Completion:
         set_completer_function(action, func)
         set_completer_method(action, method)
 
+    There are times when what's being tab completed is determined by a previous argument on the command line.
+    In theses cases, Autocompleter can pass an argparse Namespace that maps the command line tokens up through the
+    one being completed to their argparse argument. To receive this Namespace, your choices/completer function
+    should have an argument called arg_tokens.
+
+        Example:
+            def my_choices_method(self, arg_tokens)
+            def my_completer_method(self, text, line, begidx, endidx, arg_tokens)
+
+    All members of the arg_tokens Namespace are lists, even if a particular argument expects only 1 token. Since
+    AutoCompleter is for tab completion, it does not convert the tokens to their actual argument types or validate
+    their values. All tokens are stored in the Namespace as the raw strings provided on the command line. It is up to
+    the developer to determine if the user entered the correct argument type (e.g. int) and validate their values.
+
 CompletionItem Class:
     This class was added to help in cases where uninformative data is being tab completed. For instance,
     tab completing ID numbers isn't very helpful to a user without context. Returning a list of CompletionItems