Among\u00a0the advanced features provided in the SmartFoxServer SDK is the ability to exchange any class instance between client and server with minimal coding intervention. This is particularly useful for statically typed languages such as Java, C# and Actionscript, while dynamic languages such as Javascript are not directly supported.<\/p>\n
In this article we’re going to\u00a0discuss\u00a0an alternative way to implement custom serialization for classes that are needed from both client and server side to implement our game logic.<\/p>\n
If you’re not entirely familiar with the topic of class serialization in SFS2X we recommend reading this article from our documentation<\/a><\/p>\n SmartFoxServer\u00a0provides\u00a0two fundamental classes, SFSObject<\/strong> and SFSArray<\/strong>, on both client and server side that are\u00a0used to exchange data between the two end points.<\/p>\n SFSObject<\/strong> and SFSArray<\/strong> represent platform-neutral, high level objects that abstract the data transport between client and server. They\u00a0can be used to represent data in form of a Map\/Dictionary or List\/Array respectively,\u00a0supporting multiple\u00a0data types\u00a0and nested objects to create complex data structures.<\/p>\n Both classes also support two generic getClass()<\/strong>\/putClass()<\/strong> methods that allow to serialize custom class instances provided they implement a specific interface. This is particularly useful when we need to exchange specific game entities such as characters, NPCs, weapons etc. between client and server (if you need more info on this please refer to the documentation here<\/a>).<\/p>\n As alluded in this article intro, not all languages are supported: for example Javascript<\/strong>\u00a0with its dynamic structure and classless OOP foundations doesn’t work well\u00a0with class serialization. One simple and elegant solution is to add a couple of specialized methods to our game entities, to serialize\/deserialize them before we send them over the network.<\/p>\n To demonstrate this approach we can jump straight into an example: imagine we have a weapon entity that we need to send from server to client and viceversa.<\/p>\n This is the server side implementation in Java. The toSFSObject()<\/strong> method\u00a0wraps the properties we need to exchange with the client in an SFSObject ready to be sent alongside other data, if needed. The fromSFSObject()<\/strong> works in the opposite direction, by taking an entity’s serialized data and rebuilding the original object. <\/p>\n Now we can take a look at the relative implementation in Javascript:<\/p>\n\u00bb The Basics<\/h2>\n
\nSo what options do we have if we need to exchange custom objects between client and servers?<\/p>\n\u00bb\u00a0Custom serialization<\/h2>\n
\r\npublic class GammaRayGun\r\n{\r\n\tprivate int reloadTime;\r\n\tprivate int magazineSize;\r\n\tprivate double damagePerSecond;\r\n\tprivate double accuracy;\r\n\t\r\n\tpublic GammaRayGun()\r\n\t{\r\n\t\r\n\t}\r\n\t\r\n\t\/\/ ...\r\n\t\/\/ getters and setters\r\n\t\/\/ ...\r\n\t\r\n\tpublic ISFSObject toSFSObject()\r\n\t{\r\n\t\tISFSObject sfso = new SFSObject();\r\n\t\tsfso.putInt("rt", reloadTime);\r\n\t\tsfso.putInt("ms", magazineSize);\r\n\t\tsfso.putDouble("ds", damagePerSecond);\r\n\t\tsfso.putDouble("ac", accuracy);\r\n\t\t\r\n\t\treturn sfso;\r\n\t}\r\n\t\r\n\tpublic static GammaRayGun fromSFSObject(ISFSObject sfso)\r\n\t{\r\n\t\tGammaRayGun gun = new GammaRayGun();\r\n\t\t\r\n\t\tgun.setReloadTime( sfso.getInt("rt") );\r\n\t\tgun.setMagazineSize( sfso.getInt("ms") );\r\n\t\tgun.setDamagePerSecond( sfso.getDouble("ds") );\r\n\t\tgun.setAccuracy( sfso.getDouble("ac") );\t\t\r\n\t\t\r\n\t\treturn gun;\r\n\t}\r\n}\r\n<\/pre>\n\r\nvar GammaRayGun = function() \r\n{\r\n\tthis.reloadTime = 0\r\n\tthis.magazineSize = 0\r\n\tthis.damagePerSecond = 0\r\n\tthis.accuracy = 0\r\n}\r\n\r\nGammaRayGun.prototype.toSFSObject = function()\r\n{\r\n\tvar sfso = new SFS2X.SFSObject()\r\n\tsfso.putInt("rt", this.reloadTime)\r\n\tsfso.putInt("ms", this.magazineSize)\r\n\tsfso.putDouble("ds", this.damagePerSecond)\r\n\tsfso.putDouble("ac", this.accuracy)\r\n\t\r\n\treturn sfso\r\n}\r\n\r\nGammaRayGun.fromSFSObject = function(sfso)\r\n{\r\n\tvar gun = new GammaRayGun()\r\n\r\n\tgun.reloadTime = sfso.getInt("rt")\r\n\tgun.magazineSize = sfso.getInt("ms")\r\n\tgun.damagePerSecond = sfso.getDouble("ds")\r\n\tgun.accuracy = sfso.getDouble("ac")\r\n\r\n\treturn gun\r\n}\r\n<\/pre>\n