stockpiles: user friendly error handling

* display errors in the GUI when necessary
* handle older versions of DFHack without the persist module

plugins/lua/stockpiles.lua

@@ -9,12 +9,19 @@ local _ENV = mkmodule('plugins.stockpiles')
  * stockpiles_save(file), with full path
 
 --]]
+--
+function safe_require(module)
+    local status, module = pcall(require, module)
+    return status and module or nil
+end
+
 
 local gui = require 'gui'
 local script = require 'gui.script'
-local persist = require 'persist-table'
+local persist = safe_require('persist-table')
 
 function init()
+    if persist == nil then return end
     if dfhack.isMapLoaded() then
         if persist.GlobalTable.stockpiles == nil then
             persist.GlobalTable.stockpiles = {}
@@ -33,13 +40,21 @@ end
 
 function load_settings()
     init()
+    local path = get_path()
+    local ok, list = pcall(stockpiles_list_settings, path)
+    if not ok then
+        show_message_box("Stockpile Settings", "The stockpile settings folder doesn't exist.", true)
+        return
+    end
+    if #list == 0 then
+        show_message_box("Stockpile Settings", "There are no saved stockpile settings.", true)
+        return
+    end
     script.start(function()
-        local path = persist.GlobalTable.stockpiles['settings_path']
-        local list = stockpiles_list_settings(path)
         local tok,i = script.showListPrompt('Stockpile Settings','Load which stockpile?',COLOR_WHITE,tablify(list))
         if tok then
             local filename = list[i];
-            stockpiles_load(path..'/'..filename);
+            stockpiles_load(path..'/'..filename)
         end
     end)
 end
@@ -47,15 +62,19 @@ end
 function save_settings(stockpile)
     init()
     script.start(function()
-        --local sp = dfhack.gui.geSelectedBuilding(true)
         local suggested = stockpile.name
         if #suggested == 0 then
             suggested = 'Stock1'
         end
-        local path = persist.GlobalTable.stockpiles['settings_path']
+        local path = get_path()
         local sok,filename = script.showInputPrompt('Stockpile Settings', 'Enter stockpile name', COLOR_WHITE, suggested)
         if sok then
-            stockpiles_save(path..'/'..filename);
+            if filename == nil or filename == '' then
+                script.showMessage('Stockpile Settings', 'Invalid File Name', COLOR_RED)
+            else
+                print("saving...", path..'/'..filename)
+                stockpiles_save(path..'/'..filename)
+            end
         end
     end)
 end
@@ -76,6 +95,16 @@ function manage_settings(sp)
     end)
 end
 
+function show_message_box(title, msg, iserror)
+    local color = COLOR_WHITE
+    if iserror then
+        color = COLOR_RED
+    end
+    script.start(function()
+        script.showMessage(title, msg, color)
+    end)
+end
+
 function guard()
     if not string.match(dfhack.gui.getCurFocus(), '^dwarfmode/QueryBuilding/Some/Stockpile') then
         qerror("This script requires a stockpile selected in the 'q' mode")
@@ -86,11 +115,18 @@ end
 
 function set_path(path)
     init()
+    if persist == nil then
+        qerror("This version of DFHack doesn't support setting the stockpile settings path. Sorry.")
+        return
+    end
     persist.GlobalTable.stockpiles['settings_path'] = path
 end
 
 function get_path()
     init()
+    if persist == nil then
+        return "stocksettings"
+    end
     return persist.GlobalTable.stockpiles['settings_path']
 end
 

plugins/stockpiles/StockpileSerializer.cpp

@@ -87,7 +87,7 @@ bool StockpileSerializer::serialize_to_file ( const std::string & file )
     std::fstream output ( file, std::ios::out | std::ios::binary |  std::ios::trunc );
     if ( output.fail()  )
     {
-        *mOut <<  "ERROR: failed to open file for writing: " <<  file <<  endl;
+        debug() <<  "ERROR: failed to open file for writing: " <<  file <<  endl;
         return false;
     }
     return serialize_to_ostream ( &output );
@@ -109,7 +109,7 @@ bool StockpileSerializer::unserialize_from_file ( const std::string & file )
     std::fstream input ( file, std::ios::in | std::ios::binary );
     if ( input.fail()  )
     {
-        *mOut <<  "ERROR: failed to open file for reading: " <<  file <<  endl;
+        debug() <<  "ERROR: failed to open file for reading: " <<  file <<  endl;
         return false;
     }
     return parse_from_istream ( &input );

plugins/stockpiles/stockpiles.cpp

@@ -13,6 +13,7 @@
 #include "StockpileSerializer.h"
 
 
+#include "modules/Filesystem.h"
 #include "modules/Gui.h"
 #include "modules/Filesystem.h"
 
@@ -331,6 +332,30 @@ bool manage_settings ( building_stockpilest *sp )
     return true;
 }
 
+bool show_message_box ( const std::string & title,  const std::string & msg,  bool is_error = false )
+{
+    auto L = Lua::Core::State;
+    color_ostream_proxy out ( Core::getInstance().getConsole() );
+
+    CoreSuspendClaimer suspend;
+    Lua::StackUnwinder top ( L );
+
+    if ( !lua_checkstack ( L, 4 ) )
+        return false;
+
+    if ( !Lua::PushModulePublic ( out, L, "plugins.stockpiles", "show_message_box" ) )
+        return false;
+
+    Lua::Push ( L, title );
+    Lua::Push ( L, msg );
+    Lua::Push ( L, is_error );
+
+    if ( !Lua::SafeCall ( out, L, 3, 0 ) )
+        return false;
+
+    return true;
+}
+
 struct stockpiles_import_hook : public df::viewscreen_dwarfmodest
 {
     typedef df::viewscreen_dwarfmodest interpose_base;
@@ -498,6 +523,8 @@ static void stockpiles_load ( color_ostream &out, std::string filename )
     params.push_back ( filename );
     command_result r = loadstock ( out, params );
     out <<  " result = "<<  r <<  endl;
+    if ( r !=  CR_OK )
+        show_message_box ( "Stockpile Settings Error", "Couldn't load. Does the folder exist?",  true );
 }
 
 
@@ -509,6 +536,8 @@ static void stockpiles_save ( color_ostream &out, std::string filename )
     params.push_back ( filename );
     command_result r = savestock ( out, params );
     out <<  " result = "<<  r <<  endl;
+    if ( r !=  CR_OK )
+        show_message_box ( "Stockpile Settings Error", "Couldn't save. Does the folder exist?",  true );
 }
 
 DFHACK_PLUGIN_LUA_FUNCTIONS
@@ -526,3 +555,4 @@ DFHACK_PLUGIN_LUA_COMMANDS
 
 
 
+