Added multi envvar docs

2 files changed, 38 insertions, 0 deletions

diff --git a/docs/api.rst b/docs/api.rst
index 8e0ee67..dbce2c1 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -104,6 +104,7 @@ Types
 .. autoclass:: IntRange
 
 .. autoclass:: ParamType
+   :members:
 
 Exceptions
 ----------
diff --git a/docs/options.rst b/docs/options.rst
index 0ac6978..5e2d8eb 100644
--- a/docs/options.rst
+++ b/docs/options.rst
@@ -424,6 +424,43 @@ And from the command line:
 In that case it can also be a list of different environment variables
 where the first one is picked.
 
+Multiple Values from Environment Values
+---------------------------------------
+
+As options can accept multiple values pulling in such values from
+environment variables (which are strings) is a bit more complex.  The way
+click solves this is by leaving it up to the type to customize this
+behavior.  For both ``multiple`` and ``nargs`` with other values than
+``1`` click will invoke the :meth:`ParamType.split_envvar_value` method to
+perform the splitting.
+
+The default implementation for all types is to split on whitespace.  The
+exception to this rules are the :class:`File` and :class:`Path` types
+which both split according to the operating system's path splitting rules.
+On UNIX systems like Linux and OS X the splitting happens for those on
+every colon (``:``) and for Windows on a semicolon (``;``).
+
+Example usage:
+
+.. click:example::
+
+    @click.command()
+    @click.option('paths', '--path', envvar='PATHS', multiple=True,
+                  type=click.Path())
+    def perform(paths):
+        for path in paths:
+            click.echo(path)
+
+    if __name__ == '__main__':
+        perform()
+
+And from the command line:
+
+.. click:run::
+
+    import os
+    invoke(perform, env={'PATHS': './foo/bar%s./test' % os.path.pathsep})
+
 Other Prefix Characters
 -----------------------