FlxSave: Allow custom handling of parsing errors

[Geokureli]

Adds a backupParser arg to bind, which is called to handle parsing errors, also adds FlxSaveStatus.LOAD_ERROR which is an error that happened during the bind (load) process, where ERROR happened during the flush (save) process that was not resolved.

Alternative to #3270, any thoughts @EliteMasterEric ?

When the load error is a parsing error, the raw save data and parsing exception are available in the save's state. To repair the save, manually edit and/or unserialize it, wipe the old save and replace it with the new, repaired data

Example

package states;

import flixel.FlxG;
import flixel.util.FlxSave;
import haxe.Exception;
import haxe.Json;
import haxe.Serializer;
import haxe.Unserializer;
import openfl.net.SharedObject;

#if generateData
enum Values { A; B; }
#end

class SaveCrashTestState3270 extends flixel.FlxState
{
    inline static var INVALID_DATA = "oy8:someDatafy5:valuewy13:states.Valuesy1:B:0y9:otherDatay6:stringg";
    
    
    var save:FlxSave;
    
    override function create()
    {
        super.create();
        
        #if generateData
        // Used to get `INVALID_DATA`
        final data = { someData:false, value: Values.B, otherData:"string" };
        trace('serializing data${Json.stringify(data)}');
        final serialized = Serializer.run(data);
        trace('serialized data: ${serialized}');
        trace(Serializer.run({ someData:false, otherData:"string" }));
        #else
        runTest();
        #end
    }
    
    function runTest()
    {
        trace('Saving invalid data: "$INVALID_DATA"');
        saveRawData("test-save", INVALID_DATA);
        trace('loading "test-save"');
        save = new FlxSave();
        save.bind("test-save", resolveParsingError);
        switch save.status
        {
            case BOUND(_,_):
                trace('Bind successful: ${Json.stringify(save.data)}');
                trace('Erasing save');
                save.erase();
            case found:
                trace('Bind failed: $found');
        }
    }
    
    function resolveParsingError(rawData:String, e:Exception)
    {
        trace('Parsing failed, data:"$rawData", error:"$e"');
        
        trace("patching data");
        final reg = ~/y5:valuewy13:states.Valuesy.:.+:0/;
        final patchedData = reg.split(rawData).join("");
        
        trace('Resolving patched data: "$patchedData"');
        final unserializer = new Unserializer(patchedData);
        final resolver = { resolveEnum: Type.resolveEnum, resolveClass: FlxSave.resolveFlixelClasses };
        unserializer.setResolver(cast resolver);
        final parsedData = unserializer.unserialize();
        trace('resolving data: ${Json.stringify(parsedData)}');
        return parsedData;
    }
    
    @:access(openfl.net.SharedObject)
    @:access(flixel.util.FlxSave)
    function saveRawData(name:String, encodedData:String)
    {
        final meta = openfl.Lib.current.stage.application.meta;
        var path = meta["company"];
        if (path == null || path == "")
            path = "HaxeFlixel";
        else
            path = FlxSave.validate(path);
        
        final obj = SharedObject.getLocal(name, path);
        
        // put outdated data in save
        // copied from SharedObject.hx flush
        #if (js && html5)
            var storage = js.Browser.getLocalStorage();
            
            if (storage != null)
            {
                storage.removeItem(obj.__localPath + ":" + obj.__name);
                storage.setItem(obj.__localPath + ":" + obj.__name, encodedData);
            }
        #else
            var path = SharedObject.__getPath(obj.__localPath, obj.__name);
            var directory = haxe.io.Path.directory(path);
            
            if (!sys.FileSystem.exists(directory))
            {
                SharedObject.__mkdir(directory);
            }
            
            var output = sys.io.File.write(path, false);
            output.writeString(encodedData);
            output.close();
        #end
    }
}

[EliteMasterEric]

Reading on my phone, but seems good to me. As long as there's a way to handle errors during parsing.

[Geokureli]

Added an optional backupParser arg to bind. If unserializing fails, the backup parser is used, otherwise, same as my previous version, the save is stuck in an error state until you try binding again