# HG changeset patch
# User jbe
# Date 1500771073 -7200
# Node ID d89813dd4d922f537520ba46917acf41e37b69e9
# Parent  3b4dbabca31f0f1972550a5390280eeb77a59f50
New function request.add_error_handler(...); Allow layout_ident to be passed directly to slot.render_layout(...)

diff -r 3b4dbabca31f -r d89813dd4d92 framework/env/request/__init.lua
--- a/framework/env/request/__init.lua	Sun Jul 02 04:22:20 2017 +0200
+++ b/framework/env/request/__init.lua	Sun Jul 23 02:51:13 2017 +0200
@@ -32,5 +32,6 @@
   request._forward_processed = false
   request._redirect = nil
   request._csrf_secret = nil
+  request._error_handlers = {}
 
 end)
diff -r 3b4dbabca31f -r d89813dd4d92 framework/env/request/add_error_handler.lua
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/framework/env/request/add_error_handler.lua	Sun Jul 23 02:51:13 2017 +0200
@@ -0,0 +1,17 @@
+--[[--
+request.add_error_handler(
+  function(errobj, stacktrace)
+    ...
+  end
+)
+
+Registers a function to be called after an error occurred during request handling and the error response has been prepared by filling the "trace" and "system_error" slots in request.handler(...). The registered handler may, for example, send an error report to an administrator (utilizing slot.render_layout(...)). The passed handler function gets the error message (or error object) passed as first argument and the stacktrace as second argument.
+
+--]]--
+
+function request.add_error_handler(func)
+  request.configure(function()
+    local handlers = request._error_handlers
+    handlers[#handlers+1] = func
+  end)
+end
diff -r 3b4dbabca31f -r d89813dd4d92 framework/env/request/handler.lua
--- a/framework/env/request/handler.lua	Sun Jul 02 04:22:20 2017 +0200
+++ b/framework/env/request/handler.lua	Sun Jul 23 02:51:13 2017 +0200
@@ -261,6 +261,9 @@
       slot.put(encode.html_newlines(encode.html(stacktrace)))
       slot.put("</p>")
     end)
+    for i, error_handler in ipairs(request._error_handlers) do
+      error_handler(error_info.errobj, error_info.stacktrace)
+    end
   elseif redirect_data then
     if
       redirect_data.include_tempstore == true or (
diff -r 3b4dbabca31f -r d89813dd4d92 framework/env/slot/render_layout.lua
--- a/framework/env/slot/render_layout.lua	Sun Jul 02 04:22:20 2017 +0200
+++ b/framework/env/slot/render_layout.lua	Sun Jul 23 02:51:13 2017 +0200
@@ -1,20 +1,23 @@
 --[[--
-output =              -- document/data to be sent to the web browser
-slot.render_layout()
+output =             -- document/data to be sent to the web browser
+slot.render_layout(
+  layout_ident       -- if set, selects layout to be used; otherwise layout set by slot.set_layout(...) is used
+)
 
 This function returns the selected layout after replacing all slot placeholders with the respective slot contents. If slot.set_layout(...) was called with nil as first argument, then no layout will be used, but only the contents of the slot named "data" are returned.
 
 --]]--
 
-function slot.render_layout()
-  if slot._current_layout then
+function slot.render_layout(layout_ident)
+  local layout_ident = layout_ident or slot._current_layout
+  if layout_ident then
     local layout_file = assert(io.open(
       encode.file_path(
         WEBMCP_BASE_PATH,
         'app',
         WEBMCP_APP_NAME,
         '_layout',
-        slot._current_layout .. '.html'
+        layout_ident .. '.html'
       ),
       'r'
     ))