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  • IComparable not included when serializing in WCF

    - by djerry
    Hey guys, I have a list i'm filling at server side. It's a list of "User", which implements IComparable. Now when WCF is serializing the data, i guess it's not including the CompareTo method. This is my Object class : [DataContract] public class User : IComparable { private string e164, cn, h323; private int id; private DateTime lastActive; [DataMember] public DateTime LastActive { get { return lastActive; } set { laatstActief = value; } } [DataMember] public int Id { get { return id; } set { id = value; } } [DataMember] public string H323 { get { return h323; } set { h323 = value; } } [DataMember] public string Cn { get { return cn; } set { cn = value; } } [DataMember] public string E164 { get { return e164; } set { e164 = value; } } public User() { } public User(string e164, string cn, string h323, DateTime lastActive) { this.E164 = e164; this.Cn = cn; this.H323 = h323; this.LastActive= lastActive; } [DataMember] public string ToStringExtra { get { if (h323 != "/" && h323 != "") return h323 + " (" + e164 + ")"; return e164; } set { ;} } public override string ToString() { if (Cn.Equals("Trunk Line") || Cn.Equals("")) if (h323.Equals("")) return E164; else return h323; return Cn; } public int CompareTo(object obj) { User user = (User)obj; return user.LastActive.CompareTo(this.LastActive); } } Is it possible to get the CompareTo method to reach the client? Putting [DataMember] isn't the solution as i tried it ( i know...). Thanks in advance.

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  • Implementing IXmlSerializable on a generated class that has XmlTypeAttribute

    - by Josh
    Basically, the initial problem is I need to make a boolean value serialize as 0 or 1. The solution I found was to implement IXmlSerializable, which I did. Unfortunately the class I'm trying to serialize is generated code off a schema and has an XmlTypeAttribute on it. When I try to (de)serialize the object with the XmlSerializer created in the usual manner ( new XmlSerializer(type)) it throws this exception: System.InvalidOperationException: Only XmlRoot attribute may be specified for the type ______ Please use XmlSchemaProviderAttribute to specify schema type. Two options come to mind immediatly: 1) remove the attribute in the generated code. This change would have to be made every time the code was re-generated. 2) Use an XmlAttributeOverrides object when creating the serializer to remove the attribute. This would require the rest of the code base to "know" that it needs to override that attribute. Also, the exception thrown gives absolutly no clue as to what needs to be done to fix it. Both options kinda stink. Is there a third option?

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  • How to update non-scalar entity properties in EF 4.0?

    - by Mike
    At first I was using this as an extension method to update my detached entities... Public Sub AttachUpdated(ByVal obj As ObjectContext, ByVal objectDetached As EntityObject) If objectDetached.EntityState = EntityState.Detached Then Dim original As Object = Nothing If obj.TryGetObjectByKey(objectDetached.EntityKey, original) Then obj.ApplyCurrentValues(objectDetached.EntityKey.EntitySetName, objectDetached) Else Throw New ObjectNotFoundException() End If End If End Sub Everything has been working great until I had to update non-scalar properties. Correct me if I am wrong but that is because "ApplyCurrentValues" only supports scalars. To get around this I was just saving the FK_ID field instead of the entity object relation. Now I am faced with a many to many relationship so its not that simple. I would like to do something like this... Dim Resource = RelatedResource.GetByID(item.Value) Condition.RelatedResources.Add(Resource) But when I call SaveChanges the added Resources aren't saved. I started to play around with self-tracking entities (not sure if they will help solve my prob) but it seems they cannot be serialized to ViewState and this is a requirement for me. I guess one solution would be to add the xRef table as an entity and add the fks myself but I would rather it just work how I expect it too. I am open to any suggestions on how to either save my many to many relationships or serialize self-tracking entities (if self-trackingwould even solve my problem). Thanks!

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  • XmlSerializer 'forgetting' my namespace

    - by Michel
    Hi, i have to create an XML file with all the elements prefixed, like this: <ps:Request num="123" xmlns:ps="www.ladieda.com"> <ps:ClientId>5566</ps:ClientId> <ps:Request> When i serialize my object, c# is smart and does this: <Request num="123" xmlns="www.ladieda.com"> <ClientId>5566</ClientId> <Request> That is good, because the ps: is not necessary. But is there a way to force C# to serialize all the prefixes? My serialize code is this (for incoming object pObject): String XmlizedString = null; MemoryStream memoryStream = new MemoryStream(); XmlSerializer xs = new XmlSerializer(pObject.GetType()); XmlTextWriter xmlTextWriter = new XmlTextWriter(memoryStream, Encoding.UTF8); xs.Serialize(xmlTextWriter, pObject); memoryStream = (MemoryStream)xmlTextWriter.BaseStream; XmlizedString = UTF8ByteArrayToString(memoryStream.ToArray()); return XmlizedString; private String UTF8ByteArrayToString(Byte[] characters) { UTF8Encoding encoding = new UTF8Encoding(); String constructedString = encoding.GetString(characters); return (constructedString); }

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  • How do I serialise a graph in Java without getting StackOverflowException?

    - by Tim Cooper
    I have a graph structure in java, ("graph" as in "edges and nodes") and I'm attempting to serialise it. However, I get "StackOverflowException", despite significantly increasing the JVM stack size. I did some googling, and apparently this is a well known limitation of java serialisation: that it doesn't work for deeply nested object graphs such as long linked lists - it uses a stack record for each link in the chain, and it doesn't do anything clever such as a breadth-first traversal, and therefore you very quickly get a stack overflow. The recommended solution is to customise the serialisation code by overriding readObject() and writeObject(), however this seems a little complex to me. (It may or may not be relevant, but I'm storing a bunch of fields on each edge in the graph so I have a class JuNode which contains a member ArrayList<JuEdge> links;, i.e. there are 2 classes involved, rather than plain object references from one node to another. It shouldn't matter for the purposes of the question). My question is threefold: (a) why don't the implementors of Java rectify this limitation or are they already working on it? (I can't believe I'm the first person to ever want to serialise a graph in java) (b) is there a better way? Is there some drop-in alternative to the default serialisation classes that does it in a cleverer way? (c) if my best option is to get my hands dirty with low-level code, does someone have an example of graph serialisation java source-code that can use to learn how to do it?

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  • Delphi: Transporting Objects to remote computers

    - by pr0wl
    Hallo. I am writing a tier2 ordering software for network usage. So we have client and server. On the client I create Objects of TBest in which the Product ID, the amount and the user who orders it are saved. (So this is a item of an Order). An order can have multiple items and those are saved in an array to later send the created order to the server. The class that holds the array is called TBestellung. So i created both TBest.toString: string; and TBest.fromString(source: string): TBest; Now, I send the toString result to the server via socket and on the server I create the object using fromString (its parsing the attributes received). This works as intended. Question: Is there a better and more elegant way to do that? Serialisation is a keyword, yes, but isn't that awful / difficult when you serialize an object (TBestellung in this case) that contains an Array of other Objects (TBest in this case)? //Small amendment: Before it gets asked. Yes I should create an extra (static) class for toString and fromString because otherwise the server needs to create an "empty" TBest in order to be able to use fromString.

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  • Avoiding duplicate objects in Java deserialization

    - by YGL
    I have two lists (list1 and list2) containing references to some objects, where some of the list entries may point to the same object. Then, for various reasons, I am serializing these lists to two separate files. Finally, when I deserialize the lists, I would like to ensure that I am not re-creating more objects than needed. In other words, it should still be possible for some entry of List1 to point to the same object as some entry in List2. MyObject obj = new MyObject(); List<MyObject> list1 = new ArrayList<MyObject>(); List<MyObject> list2 = new ArrayList<MyObject>(); list1.add(obj); list2.add(obj); // serialize to file1.ser ObjectOutputStream oos = new ObjectOutputStream(...); oos.writeObject(list1); oos.close(); // serialize to file2.ser oos = new ObjectOutputStream(...); oos.writeObject(list2); oos.close(); I think that sections 3.4 and A.2 of the spec say that deserialization strictly results in the creation of new objects, but I'm not sure. If so, some possible solutions might involve: Implementing equals() and hashCode() and checking references manually. Creating a "container class" to hold everything and then serializing the container class. Is there an easy way to ensure that objects are not duplicated upon deserialization? Thanks.

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  • creating new instance fails PHP

    - by as3isolib
    I am relatively new to PHP and having some decent success however I am running into this issue: If I try to create a new instance of the class GenericEntryVO, I get a 500 error with little to no helpful error information. However, if I use a generic object as the result, I get no errors. I'd like to be able to cast this object as a GenericEntryVO as I am using AMFPHP to communicate serialize data with a Flex client. I've read a few different ways to create constructors in PHP but the typical 'public function Foo()' for a class Foo was recommended for PHP 5.4.4 //in my EntryService.php class public function getEntryByID($id) { $link = mysqli_connect("localhost", "root", "root", "BabyTrackingAppDB"); if (mysqli_connect_errno()) { printf("Connect failed: %s\n", mysqli_connect_error()); exit(); } $query = "SELECT * FROM Entries WHERE id = '$id' LIMIT 1"; if ($result = mysqli_query($link, $query)) { // $entry = new GenericEntryVO(); this is where the problem lies! while ($row = mysqli_fetch_row($result)) { $entry->id = $row[0]; $entry->entryType = $row[1]; $entry->title = $row[2]; $entry->description = $row[3]; $entry->value = $row[4]; $entry->created = $row[5]; $entry->updated = $row[6]; } } mysqli_free_result($result); mysqli_close($link); return $entry; } //my GenericEntryVO.php class <?php class GenericEntryVO { public function __construct() { } public $id; public $title; public $entryType; public $description; public $value; public $created; public $updated; // public $properties; } ?>

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  • WinForm Design View Error

    - by Ramiz Uddin
    I'm getting the following error on form design: Hide Call Stack at EnvDTE80.CodeModel2.DotNetNameFromLanguageSpecific(String LanguageName) at Microsoft.VisualStudio.Design.Serialization.CodeDom.VSCodeDomParser.CodeTypeDeclarationFromCodeClass(CodeClass vsClass) at Microsoft.VisualStudio.Design.Serialization.CodeDom.VSCodeDomParser.OnNamespacePopulateTypes(Object sender, EventArgs e) at System.CodeDom.CodeNamespace.get_Types() at Microsoft.VisualStudio.Design.Serialization.CodeDom.VSCodeDomParser.Parse(TextReader codeStream) at Microsoft.VisualStudio.Design.Serialization.CodeDom.MergedCodeDomParser.System.CodeDom.Compiler.ICodeParser.Parse(TextReader stream) at System.CodeDom.Compiler.CodeDomProvider.Parse(TextReader codeStream) at Microsoft.VisualStudio.Shell.Design.Serialization.CodeDom.CodeDomDocDataAdapter.get_CompileUnit() at Microsoft.VisualStudio.Design.Serialization.CodeDom.VSCodeDomDesignerLoader.PerformLoad(IDesignerSerializationManager serializationManager) at System.ComponentModel.Design.Serialization.BasicDesignerLoader.BeginLoad(IDesignerLoaderHost host) Need help!

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  • xmlns="> was not expected

    - by Anthony Shaw
    OK. I'm trying to work on communicating with the Pivotal Tracker API, which only returns data in an XML format. I have the following XML that I'm trying to deserialize into my domain model. <?xml version="1.0" encoding="UTF-8"? <stories type="array" count="2" total="2" <story <id type="integer"2909137</id <project_id type="integer"68153</project_id <story_typebug</story_type <urlhttp://www.pivotaltracker.com/story/show/2909137</url <current_stateunscheduled</current_state <description</description <nameTest #2</name <requested_byAnthony Shaw</requested_by <created_at type="datetime"2010/03/23 20:05:58 EDT</created_at <updated_at type="datetime"2010/03/23 20:05:58 EDT</updated_at </story <story <id type="integer"2909135</id <project_id type="integer"68153</project_id <story_typefeature</story_type <urlhttp://www.pivotaltracker.com/story/show/2909135</url <estimate type="integer"-1</estimate <current_stateunscheduled</current_state <description</description <nameTest #1</name <requested_byAnthony Shaw</requested_by <created_at type="datetime"2010/03/23 20:05:53 EDT</created_at <updated_at type="datetime"2010/03/23 20:05:53 EDT</updated_at </story </stories My 'story' object is created as follows: public class story { public int id { get; set; } public int estimate { get; set; } public int project_id { get; set; } public string story_type { get; set; } public string url { get; set; } public string current_state { get; set; } public string description { get; set; } public string name { get; set; } public string requested_by { get; set; } public string labels { get; set; } public string lighthouse_id { get; set; } public string lighthouse_url { get; set; } public string owned_by { get; set; } public string accepted_at { get; set; } public string created_at { get; set; } public attachment[] attachments { get; set; } public note[] notes { get; set; } } When I execute my deserialization code, I receive the following exception: Exception: There is an error in XML document (2, 2). Inner Exception: <stories xmlns='' was not expected. I can deserialize the individual stories just fine, I just cannot deserialize this xml into an array of 'story' objects And my serialization code var byteArray = Encoding.ASCII.GetBytes(value); var stream = new MemoryStream(byteArray); var deserializedObject = new XmlSerializer(typeof (story[])).Deserialize(stream) Does anybody have any ideas?

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  • Locking on an object...

    - by Mystere Man
    I often see code like that which is shown here, ie where an object is allocated and then used as a "lock object". It seems to me that you could use any object for this, including the event itself as the lock object. Why allocate a new object that does nothing? My understanding is that calling lock() on an object doesn't actually alter the object itself, nor does it actually lock it from being used, it's simply used as a placeholder for multiple lock statements to anchor on. So my question is, is this really a good thing to do?

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  • How to return radio checked object with jQuery ?

    - by Kim
    HTML <input type="radio" name="rdName" id="uniqueID1" value="1" checked="checked"> <input type="radio" name="rdName" id="uniqueID2" value="2"> <input type="radio" name="rdName" id="uniqueID3" value="3"> jQuery #1 $('input:radio[name=rdName]:checked').val(); jQuery #2 $('input[name=rdName]:checked'); jQuery #1 gets the value of checked radio, but I need to get the whole object to get the ID. jQuery #2 get this (from Chrome Dev console). Object "0" is the actual object I need, but I am unable to just that. 0: HTMLInputElement constructor: function Object() context: HTMLDocument length: 1 prevObject: Object selector: input[name=rdName]:checked __proto__: Object Any ideas how to isolate the needed object ?

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  • using dictionaries with WebServices

    - by umit-alba
    Hi! I tried to pass a dictionary via WebServices. However it is not serializeable. So i wrote an Own Class that makes it serializeable: using System; using System.Net; using System.Windows; using System.Collections.Generic; using System.Xml.Serialization; using System.Xml; using System.Xml.Schema; namespace Platform { public class SaDictionary<TKey, TValue> : Dictionary<TKey, TValue>, IXmlSerializable { #region Constructors public SaDictionary() : base() { } public SaDictionary(IDictionary<TKey, TValue> dictionary) : base(dictionary) { } public SaDictionary(IEqualityComparer<TKey> comparer) : base(comparer) { } public SaDictionary(int capacity) : base(capacity) { } public SaDictionary(IDictionary<TKey, TValue> dictionary, IEqualityComparer<TKey> comparer) : base(dictionary, comparer) { } public SaDictionary(int capacity, IEqualityComparer<TKey> comparer) : base(capacity, comparer) { } //protected SaDictionary(SerializationInfo info, StreamingContext context) // : base(info, context) //{ //} #endregion public XmlSchema GetSchema() { return null; } public void ReadXml(XmlReader reader) { XmlSerializer keySerializer = new XmlSerializer(typeof(TKey)); XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue)); bool wasEmpty = reader.IsEmptyElement; reader.Read(); if (wasEmpty) return; while (reader.NodeType != XmlNodeType.EndElement) { reader.ReadStartElement("item"); reader.ReadStartElement("key"); TKey key = (TKey)keySerializer.Deserialize(reader); reader.ReadEndElement(); //key reader.ReadStartElement("value"); TValue value = (TValue)valueSerializer.Deserialize(reader); reader.ReadEndElement(); //value this.Add(key, value); reader.ReadEndElement(); //item // reader.MoveToContent(); } reader.ReadEndElement(); } public void WriteXml(XmlWriter writer) { XmlSerializer keySerializer = new XmlSerializer(typeof(TKey)); XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue)); foreach (TKey key in this.Keys) { writer.WriteStartElement("item"); writer.WriteStartElement("key"); keySerializer.Serialize(writer, key); writer.WriteEndElement(); //key writer.WriteStartElement("value"); TValue value = this[key]; valueSerializer.Serialize(writer, value); writer.WriteEndElement(); //value writer.WriteEndElement(); //item } } } } However i get an ArrayOfXElement back. Is there a way to cast it back to a Dictionary? greets

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  • Asp.net error object not set to a reference

    - by Frank
    Hi all, Because I rush in development (a lot of whip cracking here) and declare my objects at the top of the function and instantiate inside my try-catch block, I get a lot of the good old "object not set to an instance of an object" errors while doing TDD, and later if I do miss a branch that object was used in (doing VB now, would prefer C#) or just in every day coding, object not set to an instance of an object is a bit vague. Sure the stack trace sends me to the line the error occured at, but it would be nice if I could modify my logging to either name the object or its type because sometimes I have multiple objects on the same line. It's not the end of the world, but in the end it would save me a few minutes each day. Any ideas on how I can pass the info on which object wasn't set? Thanks

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  • What comes first in Ruby's object model?

    - by Timothy
    I've been reading Metaprogramming Ruby and the object model like the chicken or egg dilemma. In Ruby 1.8, the Object class is an instance of Class. Module's superclass is Object and is an instance of Class. Class' superclass is Module, and it is an instance of Class (self-referential). Say class SomeClass; end is defined somewhere; SomeClass is an instance of Class, however its superclass is Object. Why does an instance of Class have Object as the superclass instead of nil? Also, if Object is to exist, then Class has to exist, but then Module has to exist, but for Module to exist Object has to exist. How are these classes created?

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  • xmlns='' was not expected when deserializing nested classes

    - by Mavrik
    I have a problem when attempting to serialize class on a server, send it to the client and deserialize is on the destination. On the server I have the following two classes: [XmlRoot("StatusUpdate")] public class GameStatusUpdate { public GameStatusUpdate() {} public GameStatusUpdate(Player[] players, Command command) { this.Players = players; this.Update = command; } [XmlArray("Players")] public Player[] Players { get; set; } [XmlElement("Command")] public Command Update { get; set; } } and [XmlRoot("Player")] public class Player { public Player() {} public Player(PlayerColors color) { Color = color; ... } [XmlAttribute("Color")] public PlayerColors Color { get; set; } [XmlAttribute("X")] public int X { get; set; } [XmlAttribute("Y")] public int Y { get; set; } } (The missing types are all enums). This generates the following XML on serialization: <?xml version="1.0" encoding="utf-16"?> <StatusUpdate> <Players> <Player Color="Cyan" X="67" Y="32" /> </Players> <Command>StartGame</Command> </StatusUpdate> On the client side, I'm attempting to deserialize that into following classes: [XmlRoot("StatusUpdate")] public class StatusUpdate { public StatusUpdate() { } [XmlArray("Players")] [XmlArrayItem("Player")] public PlayerInfo[] Players { get; set; } [XmlElement("Command")] public Command Update { get; set; } } and [XmlRoot("Player")] public class PlayerInfo { public PlayerInfo() { } [XmlAttribute("X")] public int X { get; set; } [XmlAttribute("Y")] public int Y { get; set; } [XmlAttribute("Color")] public PlayerColor Color { get; set; } } However, the deserializer throws an exception: There is an error in XML document (2, 2). <StatusUpdate xmlns=''> was not expected. What am I missing or doing wrong?

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  • Powershell Select-Object from array not working

    - by Andrew
    I am trying to seperate values in an array so i can pass them to another function. Am using the select-Object function within a for loop to go through each line and separate the timestamp and value fields. However, it doesn't matter what i do the below code only displays the first select-object variable for each line. The second select-object command doesn't seem to work as my output is a blank line for each of the 6 rows. Any ideas on how to get both values $ReportData = $SystemStats.get_performance_graph_csv_statistics( (,$Query) ) ### Allocate a new encoder and turn the byte array into a string $ASCII = New-Object -TypeName System.Text.ASCIIEncoding $csvdata = $ASCII.GetString($ReportData[0].statistic_data) $csv2 = convertFrom-CSV $csvdata $newarray = $csv2 | Where-Object {$_.utilization -ne "0.0000000000e+00" -and $_.utilization -ne "nan" } for ( $n = 0; $n -lt $newarray.Length; $n++) { $nTime = $newarray[$n] $nUtil = $newarray[$n] $util = $nUtil | select-object Utilization $util $tstamp = $nTime | select-object timestamp $tstamp }

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  • Passing an object as a parameter to a windows service

    - by user220723
    Is there some way to pass an object to a windows service? I know the method myServiceController.Star(string[] arg) but i need to pass a more complex object than a string array. Actually, i don't need the object to be passed as a parameter, what i really needs is that the service can use an object created in a windows forms application. I've tried using System.Web.Script.Serialization.JavaScriptSerializer.Serialize method to convert the object into a Json but i couldn't because the object contains a circular reference. I also tried using pointers, but i couldn't becouse it is a managed type object. Any idea what can i do?

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  • How to map a search object to a class with more fields with JPA annotations

    - by Moli
    Hi all, I'm a newbie with JPA. I need to map a search object to a table. The search object has only and id, name. The big object has more fileds id, name, adress and more. I use this as big object view plaincopy to clipboardprint? I use this as big object @Entity @Table(name="users") public class User { @Id @GeneratedValue(strategy = GenerationType.AUTO) private long id; private String name; private String adress; private String keywords; } //this is my search object @XXX public class UserSearch { @Id @GeneratedValue(strategy = GenerationType.AUTO) private long id; private String name; } What annotations I need to use to map the search object to the table users? I'm using spring+struts2+hibernate+JPA. Help is appreciated! Thanks!

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  • jquery integrate form parameter in one object

    - by jesse
    There are many forms in my page. I want to merge them in one object and submit them in one object. But I find serializeArray() or serialize() do not match my request, the serializeArray function will generate a array object and serialize is used by get model, it is not an object. is there a jquery or local function can merge them in one object. I have one solution but it is not perfect, loop the array object generated by serializeArray, use $.extend to merge them in one object. is there a better method? kindly help, thanks.

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  • Register Game Object Components in Game Subsystems? (Component-based Game Object design)

    - by topright
    I'm creating a component-based game object system. Some tips: GameObject is simply a list of Components. There are GameSubsystems. For example, rendering, physics etc. Each GameSubsystem contains pointers to some of Components. GameSubsystem is a very powerful and flexible abstraction: it represents any slice (or aspect) of the game world. There is a need in a mechanism of registering Components in GameSubsystems (when GameObject is created and composed). There are 4 approaches: 1: Chain of responsibility pattern. Every Component is offered to every GameSubsystem. GameSubsystem makes a decision which Components to register (and how to organize them). For example, GameSubsystemRender can register Renderable Components. pro. Components know nothing about how they are used. Low coupling. A. We can add new GameSubsystem. For example, let's add GameSubsystemTitles that registers all ComponentTitle and guarantees that every title is unique and provides interface to quering objects by title. Of course, ComponentTitle should not be rewrited or inherited in this case. B. We can reorganize existing GameSubsystems. For example, GameSubsystemAudio, GameSubsystemRender, GameSubsystemParticleEmmiter can be merged into GameSubsystemSpatial (to place all audio, emmiter, render Components in the same hierarchy and use parent-relative transforms). con. Every-to-every check. Very innefficient. con. Subsystems know about Components. 2: Each Subsystem searches for Components of specific types. pro. Better performance than in Approach 1. con. Subsystems still know about Components. 3: Component registers itself in GameSubsystem(s). We know at compile-time that there is a GameSubsystemRenderer, so let's ComponentImageRender will call something like GameSubsystemRenderer::register(ComponentRenderBase*). pro. Performance. No unnecessary checks as in Approach 1. con. Components are badly coupled with GameSubsystems. 4: Mediator pattern. GameState (that contains GameSubsystems) can implement registerComponent(Component*). pro. Components and GameSubystems know nothing about each other. con. In C++ it would look like ugly and slow typeid-switch. Questions: Which approach is better and mostly used in component-based design? What Practice says? Any suggestions about implementation of Approach 4? Thank you.

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  • Throwing exception from a property when my object state is invalid

    - by Rumi P.
    Microsoft guidelines say: "Avoid throwing exceptions from property getters", and I normally follow that. But my application uses Linq2SQL, and there is the case where my object can be in invalid state because somebody or something wrote nonsense into the database. Consider this toy example: [Table(Name="Rectangle")] public class Rectangle { [Column(Name="ID", IsPrimaryKey = true, IsDbGenerated = true)] public int ID {get; set;} [Column(Name="firstSide")] public double firstSide {get; set;} [Column(Name="secondSide")] public double secondSide {get; set;} public double sideRatio { get { return firstSide/secondSide; } } } Here, I could write code which ensures that my application never writes a Rectangle with a zero-length side into the database. But no matter how bulletproof I make my own code, somebody could open the database with a different application and create an invalid Rectangle, especially one with a 0 for secondSide. (For this example, please forget that it is possible to design the database in a way such that writing a side length of zero into the rectangle table is impossible; my domain model is very complex and there are constraints on model state which cannot be expressed in a relational database). So, the solution I am gravitating to is to change the getter to: get { if(firstSide > 0 && secondSide > 0) return firstSide/secondSide; else throw new System.InvalidOperationException("All rectangle sides should have a positive length"); } The reasoning behind not throwing exceptions from properties is that programmers should be able to use them without having to make precautions about catching and handling them them. But in this case, I think that it is OK to continue to use this property without such precautions: if the exception is thrown because my application wrote a non-zero rectangle side into the database, then this is a serious bug. It cannot and shouldn't be handled in the application, but there should be code which prevents it. It is good that the exception is visibly thrown, because that way the bug is caught. if the exception is thrown because a different application changed the data in the database, then handling it is outside of the scope of my application. So I can't do anything about it if I catch it. Is this a good enough reasoning to get over the "avoid" part of the guideline and throw the exception? Or should I turn it into a method after all? Note that in the real code, the properties which can have an invalid state feel less like the result of a calculation, so they are "natural" properties, not methods.

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  • Storing game objects with generic object information

    - by Mick
    In a simple game object class, you might have something like this: public abstract class GameObject { protected String name; // other properties protected double x, y; public GameObject(String name, double x, double y) { // etc } // setters, getters } I was thinking, since a lot of game objects (ex. generic monsters) will share the same name, movement speed, attack power, etc, it would be better to have all that information shared between all monsters of the same type. So I decided to have an abstract class "ObjectData" to hold all this shared information. So whenever I create a generic monster, I would use the same pre-created "ObjectData" for it. Now the above class becomes more like this: public abstract class GameObject { protected ObjectData data; protected double x, y; public GameObject(ObjectData data, double x, double y) { // etc } // setters, getters public String getName() { return data.getName(); } } So to tailor this specifically for a Monster (could be done in a very similar way for Npcs, etc), I would add 2 classes. Monster which extends GameObject, and MonsterData which extends ObjectData. Now I'll have something like this: public class Monster extends GameObject { public Monster(MonsterData data, double x, double y) { super(data, x, y); } } This is where my design question comes in. Since MonsterData would hold data specific to a generic monster (and would vary with what say NpcData holds), what would be the best way to access this extra information in a system like this? At the moment, since the data variable is of type ObjectData, I'll have to cast data to MonsterData whenever I use it inside the Monster class. One solution I thought of is this, but this might be bad practice: public class Monster extends GameObject { private MonsterData data; // <- this part here public Monster(MonsterData data, double x, double y) { super(data, x, y); this.data = data; // <- this part here } } I've read that for one I should generically avoid overwriting the underlying classes variables. What do you guys think of this solution? Is it bad practice? Do you have any better solutions? Is the design in general bad? How should I redesign this if it is? Thanks in advanced for any replies, and sorry about the long question. Hopefully it all makes sense!

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  • Binary data instead of actual image in C#

    - by acadia
    Hello, I am using the below mentioned library to create a barcode which is storing in a specified location as shown below: My question is, is there a way instead of saving it to a png file I get byte data? thanks Code39 code = new Code39("10090"); code.Paint().Save("c:/NewBARCODE.png", ImageFormat.Png); using System; using System.Collections.Generic; using System.Drawing; using System.Drawing.Imaging; using System.Diagnostics; namespace BarCode39 { public class Code39Settings { private int height = 60; public int BarCodeHeight { get { return height; } set { height = value; } } private bool drawText = true; public bool DrawText { get { return drawText; } set { drawText = value; } } private int leftMargin = 10; public int LeftMargin { get { return leftMargin; } set { leftMargin = value; } } private int rightMargin = 10; public int RightMargin { get { return rightMargin; } set { rightMargin = value; } } private int topMargin = 10; public int TopMargin { get { return topMargin; } set { topMargin = value; } } private int bottomMargin = 10; public int BottomMargin { get { return bottomMargin; } set { bottomMargin = value; } } private int interCharacterGap = 2; public int InterCharacterGap { get { return interCharacterGap; } set { interCharacterGap = value; } } private int wideWidth = 2; public int WideWidth { get { return wideWidth; } set { wideWidth = value; } } private int narrowWidth = 1; public int NarrowWidth { get { return narrowWidth; } set { narrowWidth = value; } } private Font font = new Font(FontFamily.GenericSansSerif, 12); public Font Font { get { return font; } set { font = value; } } private int codeToTextGapHeight = 10; public int BarCodeToTextGapHeight { get { return codeToTextGapHeight; } set { codeToTextGapHeight = value; } } } public class Code39 { #region Static initialization static Dictionary<char, Pattern> codes; static Code39() { object[][] chars = new object[][] { new object[] {'0', "n n n w w n w n n"}, new object[] {'1', "w n n w n n n n w"}, new object[] {'2', "n n w w n n n n w"}, new object[] {'3', "w n w w n n n n n"}, new object[] {'4', "n n n w w n n n w"}, new object[] {'5', "w n n w w n n n n"}, new object[] {'6', "n n w w w n n n n"}, new object[] {'7', "n n n w n n w n w"}, new object[] {'8', "w n n w n n w n n"}, new object[] {'9', "n n w w n n w n n"}, new object[] {'A', "w n n n n w n n w"}, new object[] {'B', "n n w n n w n n w"}, new object[] {'C', "w n w n n w n n n"}, new object[] {'D', "n n n n w w n n w"}, new object[] {'E', "w n n n w w n n n"}, new object[] {'F', "n n w n w w n n n"}, new object[] {'G', "n n n n n w w n w"}, new object[] {'H', "w n n n n w w n n"}, new object[] {'I', "n n w n n w w n n"}, new object[] {'J', "n n n n w w w n n"}, new object[] {'K', "w n n n n n n w w"}, new object[] {'L', "n n w n n n n w w"}, new object[] {'M', "w n w n n n n w n"}, new object[] {'N', "n n n n w n n w w"}, new object[] {'O', "w n n n w n n w n"}, new object[] {'P', "n n w n w n n w n"}, new object[] {'Q', "n n n n n n w w w"}, new object[] {'R', "w n n n n n w w n"}, new object[] {'S', "n n w n n n w w n"}, new object[] {'T', "n n n n w n w w n"}, new object[] {'U', "w w n n n n n n w"}, new object[] {'V', "n w w n n n n n w"}, new object[] {'W', "w w w n n n n n n"}, new object[] {'X', "n w n n w n n n w"}, new object[] {'Y', "w w n n w n n n n"}, new object[] {'Z', "n w w n w n n n n"}, new object[] {'-', "n w n n n n w n w"}, new object[] {'.', "w w n n n n w n n"}, new object[] {' ', "n w w n n n w n n"}, new object[] {'*', "n w n n w n w n n"}, new object[] {'$', "n w n w n w n n n"}, new object[] {'/', "n w n w n n n w n"}, new object[] {'+', "n w n n n w n w n"}, new object[] {'%', "n n n w n w n w n"} }; codes = new Dictionary<char, Pattern>(); foreach (object[] c in chars) codes.Add((char)c[0], Pattern.Parse((string)c[1])); } #endregion private static Pen pen = new Pen(Color.Black); private static Brush brush = Brushes.Black; private string code; private Code39Settings settings; public Code39(string code) : this(code, new Code39Settings()) { } public Code39(string code, Code39Settings settings) { foreach (char c in code) if (!codes.ContainsKey(c)) throw new ArgumentException("Invalid character encountered in specified code."); if (!code.StartsWith("*")) code = "*" + code; if (!code.EndsWith("*")) code = code + "*"; this.code = code; this.settings = settings; } public Bitmap Paint() { string code = this.code.Trim('*'); SizeF sizeCodeText = Graphics.FromImage(new Bitmap(1, 1)).MeasureString(code, settings.Font); int w = settings.LeftMargin + settings.RightMargin; foreach (char c in this.code) w += codes[c].GetWidth(settings) + settings.InterCharacterGap; w -= settings.InterCharacterGap; int h = settings.TopMargin + settings.BottomMargin + settings.BarCodeHeight; if (settings.DrawText) h += settings.BarCodeToTextGapHeight + (int)sizeCodeText.Height; Bitmap bmp = new Bitmap(w, h, PixelFormat.Format32bppArgb); Graphics g = Graphics.FromImage(bmp); int left = settings.LeftMargin; foreach (char c in this.code) left += codes[c].Paint(settings, g, left) + settings.InterCharacterGap; if (settings.DrawText) { int tX = settings.LeftMargin + (w - settings.LeftMargin - settings.RightMargin - (int)sizeCodeText.Width) / 2; if (tX < 0) tX = 0; int tY = settings.TopMargin + settings.BarCodeHeight + settings.BarCodeToTextGapHeight; g.DrawString(code, settings.Font, brush, tX, tY); } return bmp; } private class Pattern { private bool[] nw = new bool[9]; public static Pattern Parse(string s) { Debug.Assert(s != null); s = s.Replace(" ", "").ToLower(); Debug.Assert(s.Length == 9); Debug.Assert(s.Replace("n", "").Replace("w", "").Length == 0); Pattern p = new Pattern(); int i = 0; foreach (char c in s) p.nw[i++] = c == 'w'; return p; } public int GetWidth(Code39Settings settings) { int width = 0; for (int i = 0; i < 9; i++) width += (nw[i] ? settings.WideWidth : settings.NarrowWidth); return width; } public int Paint(Code39Settings settings, Graphics g, int left) { #if DEBUG Rectangle gray = new Rectangle(left, 0, GetWidth(settings), settings.BarCodeHeight + settings.TopMargin + settings.BottomMargin); g.FillRectangle(Brushes.Gray, gray); #endif int x = left; int w = 0; for (int i = 0; i < 9; i++) { int width = (nw[i] ? settings.WideWidth : settings.NarrowWidth); if (i % 2 == 0) { Rectangle r = new Rectangle(x, settings.TopMargin, width, settings.BarCodeHeight); g.FillRectangle(brush, r); } x += width; w += width; } return w; } } } }

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  • Storing Objects in columns using Hibernate JPA

    - by user210791
    Is it possible to store something like the following using only one table? Right now, what hibernate will do is create two tables, one for Families and one for people. I would like for the familymembers object to be serialized into the column in the database. @Entity(name = "family") class Family{ private final List<Person> familyMembers; } class Person{ String firstName, lastName; int age; }

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