Help needed with Saving/Loading Data

Comments

• ar2rsawseen Maintainer

  May 2015

  Hello @FaustoM
  so where exactly does it crash? desktop or device?
  And are there any specific errors with crash?
  
  In your code I see settings initialization, but there is no saving part there

  Likes: FaustoM

  http://appcodingeasy.com/Gideros-Mobile

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• FaustoM Member

  May 2015

  My bad. I just noticed that I deleted the problematic code and then uploaded it here without it. I copied everything right from the ebook as I did before expecting the same error (to post it here as I should had before) but everything works fine now 8-|
  
  The code was something similar to this but I must had changed something without noticing because it is working now...
  
  OptionsScene.lua

  OptionsScene = Core.class(Sprite)   function OptionsScene:init() local optionsbg = Bitmap.new(Texture.new("images/cartoon_cat-800x600.jpg", true)) optionsbg:setAnchorPoint(0.5, 0.5) optionsbg:setPosition(conf.width/2, conf.height/2) self:addChild(optionsbg)   local optionsHeading = TextField.new(conf.fontMedium, "Options") optionsHeading:setPosition((conf.width - optionsHeading:getWidth())/2, 100) optionsHeading:setTextColor(0xffff00) self:addChild(optionsHeading)   local backText = TextField.new(conf.fontMedium, "Back") backText:setTextColor(0xffff00) local backButton = Button.new(backText) backButton:setPosition((conf.width - backButton:getWidth())/2, conf.height - 50) backButton:addEventListener("click", function() sceneManager1:changeScene("start", conf.transitionTime, conf.transition, conf.easing) end) self:addChild(backButton)     self:addEventListener(Event.KEY_DOWN, function(event) if event.KeyCode == KeyCode.BACK then sceneManager1:changeScene("start", conf.transitionTime, conf.transition, conf.easing) end end)   local usernameText = TextField.new(conf.fontSmall, "Your usarname is: "..sets:get("username")) usernameText:setPosition(100, 200) usernameText:setTextColor(0xffff00) self:addChild(usernameText)   local changeText = TextField.new(conf.fontSmall, "Change it") changeText:setTextColor(0x00ff00) local changeButton = Button.new(changeText) changeButton:setPosition(conf.width - changeButton:getWidth() - 100, 200) self:addChild(changeButton)   changeButton:addEventListener("click", function() local textinputDialog = TextInputDialog.new("Change your username", "Enter your new username", sets:get("username"), "Cancel", "Save") textinputDialog:addEventListener(Event.COMPLETE, function(event) if event.buttonIndex ~= nil then sets:set("username", event.text, true) usernameText:setText("Your username is: "..sets:get("username")) end end) textinputDialog:show() end) end

  Settings.lua

  Settings = Core.class()   function Settings:init()   --our Initial Settings local settings = { username = "Player", }   --Check if Settings changed self.isChanged = false   --loading if exist self.sets = dataSaver.load("|D|settings") if (not self.sets) then self.sets = {} end   for key, val in pairs(settings) do if self.sets[key] == nil then self.sets[key] = val self.isChanged = true end end   --save settings function Settings:save() --check if anything changed if(self.isChanged) then self.isChanged = false dataSaver.save("|D|setttings", self.sets) end end   --get value function Settings:get(key) return self.sets[key] end   --set new value function Settings:set(key, value, autosave) if(self.sets[key] == nil or self.sets[key] ~= value) then self.sets[key] = value self.isChanged = true end if autosave then self:save() end end   end

  I guess I will never know what was wrong with my previous code... Is there any detailed tutorial on saving and loading? I always find the same structure with no explanation whatsoever. Until now I found Lua very easy to understand and simple to code but this saving/loading method escapes my understanding.
  
  I am testing with Gideros Player. Should the username remain when I restart or open a new Gideros Player windows? The username is always "Player". It retains the changes from scene to scene but when I restart or open it again it is gone
  
  Thanks a lot in advance. I really appreciate the time you are taking to read this wall of text and reply.

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• pie Member

  May 2015 Accepted Answer

  Hi, this should help:
  
  http://appcodingeasy.com/Gideros-Mobile/Save-and-load-data-module-for-Gideros-Mobile
  
  About the player name not updating between restarts, I think you have a typo:
  you're saving changes on "|D|setttings" but loading "|D|settings".
  

  Likes: Holonist

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• Holonist Member

  May 2015 edited May 2015 Accepted Answer

  variant without dataSaver:

  require "json"   player = {} player.name ="holo" player.str = 2   --json.encode() converts your table to a string local serialPlayer = json.encode(player)   --serialPlayer looks like this: ["name":"holo","str":2]   --save your json string to a file local file = io.open("|D|player.txt", "w") file:write(serialPlayer) file:close()   --load the json string from your file local file = io.open("|D|player.txt", "r") local serialPlayer = file:read("*all") file:close()   --convert the string back to a table with json.decode() player = json.decode(serialPlayer)

  In reality, you will want to load your data on game start, and save them in the end.
  Here you will have to check if the file exists first

  --if player.txt exists, load player. else create empty player table/object if isFile("|D|player.txt") then local file = io.open("|D|player.txt", "r") local serialPlayer = file:read("*all") file:close()   player = json.decode(serialPlayer) else player = {} player.name = "" player.str = 0 end   --the function we use above to check if our save file exists function isFile(fileName) local file = io.open(fileName) if file then file:close() return true else return false end end

  That's basically how you save and load stuff.
  
  Unlike datasaver, here everytime we attempt to save/load something, the complete object gets read/overwritten, instead of single attributes. So here you have to decide between simplicity and speed. Though in my opinion, dataSaver never makes a noteable difference, unless you're working with HUGE tables (10k+ entries). And in the end, even datasaver has to rewrite the whole txt file anyway.
  
  If you want to encrypt your savegames with the same method, have a look at
  http://giderosmobile.com/forum/discussion/5625/simple-savegame-encryption#Item_1
  
  You can add me on Skype (theholonist) if you like

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• FaustoM Member

  May 2015

  Hi @pie and @Holonist. After correcting that typo @pie mentioned everything works as it should. Thanks a lot. @Holonist, I will mess around with that other way of saving you posted, it looks cleaner in some parts. The encryption is also welcomed. Thanks a lot for both of your time. I really appreciate the help.

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