--- rat/lonwrapper.pm	2020/01/14 14:26:39	1.70
+++ rat/lonwrapper.pm	2020/01/14 16:48:06	1.71
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Wrapper for external and binary files as standalone resources
 #
-# $Id: lonwrapper.pm,v 1.70 2020/01/14 14:26:39 raeburn Exp $
+# $Id: lonwrapper.pm,v 1.71 2020/01/14 16:48:06 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -427,7 +427,7 @@ described at http://www.lon-capa.org.
 
 =over
 
-=item wrapper($r,$url,$brcrum,$absolute,$is_ext,$is_pdf,$linktext,$explanation,$title,$width,$height)
+=item wrapper($r,$url,$brcrum,$absolute,$is_ext,$is_pdf,$exttool,$linktext,$explanation,$title,$width,$height)
 
 =over
 
@@ -437,8 +437,11 @@ request object
 
 =item $url
 
-url to display by including in an iframe within a
-LON-CAPA page which has a standard LON-CAPA inline menu.
+url to display either by including in an iframe within a
+LON-CAPA page which has a standard LON-CAPA inline menu,
+or in some cases launched in a separate tab or window,
+launched via a link in a LON-CAPA page with standard inline
+menu.
 
 =item $brcrum
 
@@ -473,6 +476,22 @@ true if URL is for an external resource.
 
 true if URL is for a PDF (based on file extension).
 
+=item $exttool
+
+If URL is for an External Tool, will contain the target type: iframe, window or tab.
+
+=item $linktext
+
+optional. If URL is for an External Tool, and target type is window or tab, 
+then the link text may be an option set in the course for each tool instance,
+or may be a default defined in the domain for all instances of the tool.
+
+=item $explanation
+
+optional. If URL is for an External Tool, and target type is window or tab, 
+then the explanation is an option set in the course for each tool instance,
+or may be a default defined in the domain for all instances of the tool.
+
 =item $title
 
 optional. If wrapped item is a PDF, and $env{'browser.mobile'} 
@@ -481,12 +500,45 @@ above the link, but if not provided as a
 will be used, otherwise, the filename will be displayed (unless
 hidden URL set for the resource).
 
+=item $width
+
+optional. If URL is for an External Tool, and target type is window,
+then a default width may have been defined in the domain for all instances of 
+the tool.  If so, that width will be used for the window opened (via a link)
+to launch the external tool.
+
+=item $height
+
+optional. If URL is for an External Tool, and target type is window,
+then a default height may have been defined in the domain for all instances of 
+the tool.  If so, that height will be used for the window opened (via a link)
+to launch the external tool.
+
 =back
 
 Returns markup for the entire page.
 
 =item handler()
 
+Content handler for requests for: /adm/wrapper/...
+used for content to be displayed in an iframe, or launched in a separate tab
+or window via a link.  The target URL is extracted from the requested URL, by
+removing the /adm/wrapper prefix. 
+
+The target URL will typically be a PDF served from the current server, an 
+external resource URL served from a different server, or an external tool
+(from an LTI Provider) launched from LON-CAPA (as LTI Consumer) and launched
+via a link.
+
+If the request included forceedit in the query string, and the requester has
+rights to modify course content, then the editor will be didplayed to allow
+changes to be made to the resource (e.g., change the URL of the external resource,
+or change the setting for the external tool instance.
+
+If not in edit mode, then the wrapper() subroutine will be called to generate the
+standard LON-CAPA inline menu, and then either a link to launch a separate tab or
+window, or an iframe to display the content inline. 
+
 =back
 
 =cut