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• [.NET Remoting] Mixing secure & unsecure channels

  - by user305023

  I am unable to use an unsecure channel once a secure channel has already been registered. The code below works only if on the client side, the unsecured channel is registered before. Is it possible to mix secure and unsecure channels without any contraints on the registration order ? using System; using System.Collections; using System.Runtime.Remoting; using System.Runtime.Remoting.Channels; using System.Runtime.Remoting.Channels.Tcp; public class SampleObject : MarshalByRefObject { public DateTime GetTest() { return DateTime.Now; } } public class SampleObject2 : MarshalByRefObject { public DateTime GetTest2() { return DateTime.Now; } } static class ProgramClient { private static TcpClientChannel RegisterChannel(bool secure, string name, int priority) { IDictionary properties = new Hashtable(); properties.Add("secure", secure); properties.Add("name", name); properties.Add("priority", priority); var clientChannel = new TcpClientChannel(properties, null); ChannelServices.RegisterChannel(clientChannel, false); return clientChannel; } private static void Secure() { RegisterChannel(true, "clientSecure", 2); var testSecure = (SampleObject2)Activator.GetObject(typeof(SampleObject2), "tcp://127.0.0.1:8081/Secured.rem"); Console.WriteLine("secure: " + testSecure.GetTest2().ToLongTimeString()); } private static void Unsecure() { RegisterChannel(false, "clientUnsecure", 1); var test = (SampleObject)Activator.GetObject(typeof(SampleObject), "tcp://127.0.0.1:8080/Unsecured.rem"); Console.WriteLine("unsecure: " + test.GetTest().ToLongTimeString()); } internal static void MainClient() { Console.Write("Press Enter to start."); Console.ReadLine(); // Works only in this order Unsecure(); Secure(); Console.WriteLine("Press ENTER to end"); Console.ReadLine(); } } static class ProgramServer { private static TcpServerChannel RegisterChannel(int port, bool secure, string name) { IDictionary properties = new Hashtable(); properties.Add("port", port); properties.Add("secure", secure); properties.Add("name", name); //properties.Add("impersonate", false); var serverChannel = new TcpServerChannel(properties, null); ChannelServices.RegisterChannel(serverChannel, secure); return serverChannel; } private static void StartUnsecure() { RegisterChannel(8080, false, "unsecure"); RemotingConfiguration.RegisterWellKnownServiceType(typeof(SampleObject), "Unsecured.rem", WellKnownObjectMode.Singleton); } private static void StartSecure() { RegisterChannel(8081, true, "secure"); RemotingConfiguration.RegisterWellKnownServiceType(typeof(SampleObject2), "Secured.rem", WellKnownObjectMode.Singleton); } internal static void MainServer() { StartUnsecure(); StartSecure(); Console.WriteLine("Unsecure: 8080\n Secure: 8081"); Console.WriteLine("Press the enter key to exit..."); Console.ReadLine(); } } class Program { static void Main(string[] args) { if (args.Length == 1 && args[0] == "server") ProgramServer.MainServer(); else ProgramClient.MainClient(); } }

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• Typesafe fire-and-forget asynchronous delegate invocation in C#

  - by LBushkin

  I recently found myself needing a typesafe "fire-and-forget" mechanism for running code asynchronously. Ideally, what I would want to do is something like: var myAction = (Action)(() => Console.WriteLine("yada yada")); myAction.FireAndForget(); // async invocation Unfortunately, the obvious choice of calling BeginInvoke() without a corresponding EndInvoke() does not work - it results in a slow resource leak (since the asyn state is held by the runtime and never released ... it's expecting an eventual call to EndInvoke(). I also can't run the code on the .NET thread pool because it may take a very long time to complete (it's advised to only run relatively short-lived code on the thread pool) - this makes it impossible to use the ThreadPool.QueueUserWorkItem(). Initially, I only needed this behavior for methods whose signature matches Action, Action<...>, or Func<...>. So I put together a set of extension methods (see listing below) that let me do this without running into the resource leak. There are overloads for each version of Action/Func. Unfortunately, I now want to port this code to .NET 4 where the number of generic parameters on Action and Func have been increased substantially. Before I write a T4 script to generate these, I was also hoping to find a simpler more elegant way to do this. Any ideas are welcome. public static class AsyncExt { public static void FireAndForget( this Action action ) { action.BeginInvoke(OnActionCompleted, action); } public static void FireAndForget<T1>( this Action<T1> action, T1 arg1 ) { action.BeginInvoke(arg1, OnActionCompleted<T1>, action); } public static void FireAndForget<T1,T2>( this Action<T1,T2> action, T1 arg1, T2 arg2 ) { action.BeginInvoke(arg1, arg2, OnActionCompleted<T1, T2>, action); } public static void FireAndForget<TResult>(this Func<TResult> func, TResult arg1) { func.BeginInvoke(OnFuncCompleted<TResult>, func); } public static void FireAndForget<T1,TResult>(this Func<T1, TResult> action, T1 arg1) { action.BeginInvoke(arg1, OnFuncCompleted<T1,TResult>, action); } // more overloads of FireAndForget<..>() for Action<..> and Func<..> private static void OnActionCompleted( IAsyncResult result ) { var action = (Action)result.AsyncState; action.EndInvoke(result); } private static void OnActionCompleted<T1>( IAsyncResult result ) { var action = (Action<T1>)result.AsyncState; action.EndInvoke( result ); } private static void OnActionCompleted<T1,T2>(IAsyncResult result) { var action = (Action<T1,T2>)result.AsyncState; action.EndInvoke(result); } private static void OnFuncCompleted<TResult>( IAsyncResult result ) { var func = (Func<TResult>)result.AsyncState; func.EndInvoke( result ); } private static void OnFuncCompleted<T1,TResult>(IAsyncResult result) { var func = (Func<T1, TResult>)result.AsyncState; func.EndInvoke(result); } // more overloads of OnActionCompleted<> and OnFuncCompleted<> }

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• BadPaddingException in Android encrypt

  - by DarthRoman

  Hi everyone, I am making an Android application, and I want to encrypt a String before sending it to a DataBase, and encrytpion is correct. The problem is when I am going to decrypt the String, because I get a BadPaddingException and I have no idea where the problem is. Here is the code: public final static String HEX = "36A52C8FB7DF9A3F"; public static String encrypt(String seed, String cleartext) throws Exception { byte[] rawKey = getRawKey(seed.getBytes()); byte[] result = encrypt(rawKey, cleartext.getBytes()); return toHex(result); } public static String decrypt(String seed, String encrypted) throws Exception { byte[] rawKey = getRawKey(seed.getBytes()); byte[] enc = toByte(encrypted); byte[] result = decrypt(rawKey, enc); return new String(result); } public static String toHex(String txt) { return toHex(txt.getBytes()); } public static String fromHex(String hex) { return new String(toByte(hex)); } public static byte[] toByte(String hexString) { int len = hexString.length()/2; byte[] result = new byte[len]; for (int i = 0; i < len; i++) result[i] = Integer.valueOf(hexString.substring(2*i, 2*i+2), 16).byteValue(); return result; } public static String toHex(byte[] buf) { if (buf == null) return ""; StringBuffer result = new StringBuffer(2*buf.length); for (int i = 0; i < buf.length; i++) { appendHex(result, buf[i]); } return result.toString(); } private static byte[] getRawKey(byte[] seed) throws Exception { KeyGenerator kgen = KeyGenerator.getInstance("AES"); SecureRandom sr = SecureRandom.getInstance("SHA1PRNG"); sr.setSeed(seed); kgen.init(128, sr); // 192 and 256 bits may not be available SecretKey skey = kgen.generateKey(); byte[] raw = skey.getEncoded(); return raw; } private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception { SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES"); Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.ENCRYPT_MODE, skeySpec); byte[] encrypted = cipher.doFinal(clear); return encrypted; } private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception { SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES"); Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.DECRYPT_MODE, skeySpec); byte[] decrypted = cipher.doFinal(encrypted); return decrypted; } private static void appendHex(StringBuffer sb, byte b) { sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f)); } I encrypt and decrypt with this code: String encrypted = encrypt(HEX, "some text"); String decrypted = decrypt(HEX, encrypted); Can anyone help me please? Thank you very much!!

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• Sqlite returns error

  - by ruruma

  I'm trying to implement loading data from database and put it into different views. But log cat returns error, that it cannot find "_id" column. Can somebody help me with this? SqlHelper Code public class FiboSqlHelper extends SQLiteOpenHelper { public static final String TABLE_FILMDB = "FiboFilmTop250"; public static final String COLUMN_ID = "_id"; private static final String DATABASE_NAME = "FiboFilmDb250.sqlite"; private static final int DATABASE_VERSION = 1; public static final String COLUMN_TITLE = "Title"; public static final String COLUMN_RATING = "Rating"; public static final String COLUMN_GENRE = "Genre"; public static final String COLUMN_TIME = "Time"; public static final String COLUMN_PREMDATE = "PremDate"; public static final String COLUMN_PLOT = "Plot"; private static final String DATABASE_CREATE = "create table "+TABLE_FILMDB+"("+COLUMN_ID +" integer primary key autoincrement, " +COLUMN_TITLE+" text not null "+COLUMN_RATING+" text not null "+COLUMN_GENRE+" text not null "+COLUMN_TIME+" text not null "+COLUMN_PREMDATE+" text not null "+COLUMN_PLOT+" "+"text not null)"; public FiboSqlHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); // TODO Auto-generated constructor stub } @Override public void onCreate(SQLiteDatabase db) { // TODO Auto-generated method stub db.execSQL(DATABASE_CREATE); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO Auto-generated method stub Log.w(FiboSqlHelper.class.getName(), "Upgrading database from version " + oldVersion + " to " + newVersion + ", which will destroy all old data"); db.execSQL("DROP TABLE IF EXISTS " + TABLE_FILMDB); onCreate(db); } }` SqlAdapterCode: public class FiboSqlAdapter { private SQLiteDatabase database; private FiboSqlHelper dbHelper; private String[] allColumns = {FiboSqlHelper.COLUMN_ID, FiboSqlHelper.COLUMN_TITLE, FiboSqlHelper.COLUMN_GENRE, FiboSqlHelper.COLUMN_PREMDATE, FiboSqlHelper.COLUMN_TIME, FiboSqlHelper.COLUMN_PLOT}; public FiboSqlAdapter (Context context){ dbHelper = new FiboSqlHelper(context); } public void open() throws SQLException { database = dbHelper.getWritableDatabase(); } public void close(){ dbHelper.close(); } public List<FilmDataEntity> getAllFilmData(){ List<FilmDataEntity> fDatas = new ArrayList<FilmDataEntity>(); Cursor cursor = database.query(FiboSqlHelper.TABLE_FILMDB, allColumns, null,null,null,null,null); cursor.moveToFirst(); while(!cursor.isAfterLast()){ FilmDataEntity fData = cursorToData(cursor); fDatas.add(fData); cursor.moveToNext(); } cursor.close(); return fDatas; } private FilmDataEntity cursorToData(Cursor cursor){ FilmDataEntity fData = new FilmDataEntity(); fData.setId(cursor.getLong(1)); fData.setTitle(cursor.getString(2)); fData.setRating(cursor.getString(6)); fData.setGenre(cursor.getString(4)); fData.setPremDate(cursor.getString(5)); fData.setShortcut(cursor.getString(8)); return fData; }} DataEntity: ` public class FilmDataEntity { private long id; private String title; private String rating; private String genre; private String premDate; private String shortcut; public String getShortcut() { return shortcut; } public void setShortcut(String shortcut) { this.shortcut = shortcut; } public String getGenre() { return genre; } public void setGenre(String genre) { this.genre = genre; } public String getPremDate() { return premDate; } public void setPremDate(String premDate) { this.premDate = premDate; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getRating() { return rating; } public void setRating(String rating) { this.rating = rating; } public long getId() { return id; } public void setId(long id) { this.id = id; } } Part from main activity: `List<FilmDataEntity> fE1; sqA = new FiboSqlAdapter(this); sqA.open(); fE1 = sqA.getAllFilmData(); `

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• What is there so useful in the Decorator Pattern? My example doesn't work

  - by Green

  The book says: The decorator pattern can be used to extend (decorate) the functionality of a certain object I have a rabbit animal. And I want my rabbit to have, for example, reptile skin. Just want to decorate a common rabbit with reptile skin. I have the code. First I have abstract class Animal with everythig that is common to any animal: abstract class Animal { abstract public function setSleep($hours); abstract public function setEat($food); abstract public function getSkinType(); /* and more methods which for sure will be implemented in any concrete animal */ } I create class for my rabbit: class Rabbit extends Animal { private $rest; private $stomach; private $skinType = "hair"; public function setSleep($hours) { $this->rest = $hours; } public function setFood($food) { $this->stomach = $food; } public function getSkinType() { return $this->$skinType; } } Up to now everything is OK. Then I create abstract AnimalDecorator class which extends Animal: abstract class AnimalDecorator extends Animal { protected $animal; public function __construct(Animal $animal) { $this->animal = $animal; } } And here the problem comes. Pay attention that AnimalDecorator also gets all the abstract methods from the Animal class (in this example just two but in real can have many more). Then I create concrete ReptileSkinDecorator class which extends AnimalDecorator. It also has those the same two abstract methods from Animal: class ReptileSkinDecorator extends AnimalDecorator { public function getSkinColor() { $skin = $this->animal->getSkinType(); $skin = "reptile"; return $skin; } } And finaly I want to decorate my rabbit with reptile skin: $reptileSkinRabbit = ReptileSkinDecorator(new Rabbit()); But I can't do this because I have two abstract methods in ReptileSkinDecorator class. They are: abstract public function setSleep($hours); abstract public function setEat($food); So, instead of just re-decorating only skin I also have to re-decorate setSleep() and setEat(); methods. But I don't need to. In all the book examples there is always ONLY ONE abstract method in Animal class. And of course it works then. But here I just made very simple real life example and tried to use the Decorator pattern and it doesn't work without implementing those abstract methods in ReptileSkinDecorator class. It means that if I want to use my example I have to create a brand new rabbit and implement for it its own setSleep() and setEat() methods. OK, let it be. But then this brand new rabbit has the instance of commont Rabbit I passed to ReptileSkinDecorator: $reptileSkinRabbit = ReptileSkinDecorator(new Rabbit()); I have one common rabbit instance with its own methods in the reptileSkinRabbit instance which in its turn has its own reptileSkinRabbit methods. I have rabbit in rabbit. But I think I don't have to have such possibility. I don't understand the Decarator pattern right way. Kindly ask you to point on any mistakes in my example, in my understanding of this pattern. Thank you.

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• C#: Why Decorate When You Can Intercept

  - by James Michael Hare

  We've all heard of the old Decorator Design Pattern (here) or used it at one time or another either directly or indirectly.  A decorator is a class that wraps a given abstract class or interface and presents the same (or a superset) public interface but "decorated" with additional functionality.   As a really simplistic example, consider the System.IO.BufferedStream, it itself is a descendent of System.IO.Stream and wraps the given stream with buffering logic while still presenting System.IO.Stream's public interface:   1: Stream buffStream = new BufferedStream(rawStream); Now, let's take a look at a custom-code example.  Let's say that we have a class in our data access layer that retrieves a list of products from a database:  1: // a class that handles our CRUD operations for products 2: public class ProductDao 3: { 4: ... 5:  6: // a method that would retrieve all available products 7: public IEnumerable<Product> GetAvailableProducts() 8: { 9: var results = new List<Product>(); 10:  11: // must create the connection 12: using (var con = _factory.CreateConnection()) 13: { 14: con.ConnectionString = _productsConnectionString; 15: con.Open(); 16:  17: // create the command 18: using (var cmd = _factory.CreateCommand()) 19: { 20: cmd.Connection = con; 21: cmd.CommandText = _getAllProductsStoredProc; 22: cmd.CommandType = CommandType.StoredProcedure; 23:  24: // get a reader and pass back all results 25: using (var reader = cmd.ExecuteReader()) 26: { 27: while(reader.Read()) 28: { 29: results.Add(new Product 30: { 31: Name = reader["product_name"].ToString(), 32: ... 33: }); 34: } 35: } 36: } 37: }            38:  39: return results; 40: } 41: } Yes, you could use EF or any myriad other choices for this sort of thing, but the germaine point is that you have some operation that takes a non-trivial amount of time.  What if, during the production day I notice that my application is performing slowly and I want to see how much of that slowness is in the query versus my code.  Well, I could easily wrap the logic block in a System.Diagnostics.Stopwatch and log the results to log4net or other logging flavor of choice: 1:     // a class that handles our CRUD operations for products 2:     public class ProductDao 3:     { 4:         private static readonly ILog _log = LogManager.GetLogger(typeof(ProductDao)); 5:         ... 6:         7:         // a method that would retrieve all available products 8:         public IEnumerable<Product> GetAvailableProducts() 9:         { 10:             var results = new List<Product>(); 11:             var timer = Stopwatch.StartNew(); 12:             13:             // must create the connection 14:             using (var con = _factory.CreateConnection()) 15:             { 16:                 con.ConnectionString = _productsConnectionString; 17:                 18:                 // and all that other DB code... 19:                 ... 20:             } 21:             22:             timer.Stop(); 23:             24:             if (timer.ElapsedMilliseconds > 5000) 25:             { 26:                 _log.WarnFormat("Long query in GetAvailableProducts() took {0} ms", 27:                     timer.ElapsedMillseconds); 28:             } 29:             30:             return results; 31:         } 32:     } In my eye, this is very ugly.  It violates Single Responsibility Principle (SRP), which says that a class should only ever have one responsibility, where responsibility is often defined as a reason to change.  This class (and in particular this method) has two reasons to change: If the method of retrieving products changes. If the method of logging changes. Well, we could “simplify” this using the Decorator Design Pattern (here).  If we followed the pattern to the letter, we'd need to create a base decorator that implements the DAOs public interface and forwards to the wrapped instance.  So let's assume we break out the ProductDAO interface into IProductDAO using your refactoring tool of choice (Resharper is great for this). Now, ProductDao will implement IProductDao and get rid of all logging logic: 1:     public class ProductDao : IProductDao 2:     { 3:         // this reverts back to original version except for the interface added 4:     } 5:  And we create the base Decorator that also implements the interface and forwards all calls: 1:     public class ProductDaoDecorator : IProductDao 2:     { 3:         private readonly IProductDao _wrappedDao; 4:         5:         // constructor takes the dao to wrap 6:         public ProductDaoDecorator(IProductDao wrappedDao) 7:         { 8:             _wrappedDao = wrappedDao; 9:         } 10:         11:         ... 12:         13:         // and then all methods just forward their calls 14:         public IEnumerable<Product> GetAvailableProducts() 15:         { 16:             return _wrappedDao.GetAvailableProducts(); 17:         } 18:     } This defines our base decorator, then we can create decorators that add items of interest, and for any methods we don't decorate, we'll get the default behavior which just forwards the call to the wrapper in the base decorator: 1:     public class TimedThresholdProductDaoDecorator : ProductDaoDecorator 2:     { 3:         private static readonly ILog _log = LogManager.GetLogger(typeof(TimedThresholdProductDaoDecorator)); 4:         5:         public TimedThresholdProductDaoDecorator(IProductDao wrappedDao) : 6:             base(wrappedDao) 7:         { 8:         } 9:         10:         ... 11:         12:         public IEnumerable<Product> GetAvailableProducts() 13:         { 14:             var timer = Stopwatch.StartNew(); 15:             16:             var results = _wrapped.GetAvailableProducts(); 17:             18:             timer.Stop(); 19:             20:             if (timer.ElapsedMilliseconds > 5000) 21:             { 22:                 _log.WarnFormat("Long query in GetAvailableProducts() took {0} ms", 23:                     timer.ElapsedMillseconds); 24:             } 25:             26:             return results; 27:         } 28:     } Well, it's a bit better.  Now the logging is in its own class, and the database logic is in its own class.  But we've essentially multiplied the number of classes.  We now have 3 classes and one interface!  Now if you want to do that same logging decorating on all your DAOs, imagine the code bloat!  Sure, you can simplify and avoid creating the base decorator, or chuck it all and just inherit directly.  But regardless all of these have the problem of tying the logging logic into the code itself. Enter the Interceptors.  Things like this to me are a perfect example of when it's good to write an Interceptor using your class library of choice.  Sure, you could design your own perfectly generic decorator with delegates and all that, but personally I'm a big fan of Castle's Dynamic Proxy (here) which is actually used by many projects including Moq. What DynamicProxy allows you to do is intercept calls into any object by wrapping it with a proxy on the fly that intercepts the method and allows you to add functionality.  Essentially, the code would now look like this using DynamicProxy: 1: // Note: I like hiding DynamicProxy behind the scenes so users 2: // don't have to explicitly add reference to Castle's libraries. 3: public static class TimeThresholdInterceptor 4: { 5: // Our logging handle 6: private static readonly ILog _log = LogManager.GetLogger(typeof(TimeThresholdInterceptor)); 7:  8: // Handle to Castle's proxy generator 9: private static readonly ProxyGenerator _generator = new ProxyGenerator(); 10:  11: // generic form for those who prefer it 12: public static object Create<TInterface>(object target, TimeSpan threshold) 13: { 14: return Create(typeof(TInterface), target, threshold); 15: } 16:  17: // Form that uses type instead 18: public static object Create(Type interfaceType, object target, TimeSpan threshold) 19: { 20: return _generator.CreateInterfaceProxyWithTarget(interfaceType, target, 21: new TimedThreshold(threshold, level)); 22: } 23:  24: // The interceptor that is created to intercept the interface calls. 25: // Hidden as a private inner class so not exposing Castle libraries. 26: private class TimedThreshold : IInterceptor 27: { 28: // The threshold as a positive timespan that triggers a log message. 29: private readonly TimeSpan _threshold; 30:  31: // interceptor constructor 32: public TimedThreshold(TimeSpan threshold) 33: { 34: _threshold = threshold; 35: } 36:  37: // Intercept functor for each method invokation 38: public void Intercept(IInvocation invocation) 39: { 40: // time the method invocation 41: var timer = Stopwatch.StartNew(); 42:  43: // the Castle magic that tells the method to go ahead 44: invocation.Proceed(); 45:  46: timer.Stop(); 47:  48: // check if threshold is exceeded 49: if (timer.Elapsed > _threshold) 50: { 51: _log.WarnFormat("Long execution in {0} took {1} ms", 52: invocation.Method.Name, 53: timer.ElapsedMillseconds); 54: } 55: } 56: } 57: } Yes, it's a bit longer, but notice that: This class ONLY deals with logging long method calls, no DAO interface leftovers. This class can be used to time ANY class that has an interface or virtual methods. Personally, I like to wrap and hide the usage of DynamicProxy and IInterceptor so that anyone who uses this class doesn't need to know to add a Castle library reference.  As far as they are concerned, they're using my interceptor.  If I change to a new library if a better one comes along, they're insulated. Now, all we have to do to use this is to tell it to wrap our ProductDao and it does the rest: 1: // wraps a new ProductDao with a timing interceptor with a threshold of 5 seconds 2: IProductDao dao = TimeThresholdInterceptor.Create<IProductDao>(new ProductDao(), 5000); Automatic decoration of all methods!  You can even refine the proxy so that it only intercepts certain methods. This is ideal for so many things.  These are just some of the interceptors we've dreamed up and use: Log parameters and returns of methods to XML for auditing. Block invocations to methods and return default value (stubbing). Throw exception if certain methods are called (good for blocking access to deprecated methods). Log entrance and exit of a method and the duration. Log a message if a method takes more than a given time threshold to execute. Whether you use DynamicProxy or some other technology, I hope you see the benefits this adds.  Does it completely eliminate all need for the Decorator pattern?  No, there may still be cases where you want to decorate a particular class with functionality that doesn't apply to the world at large. But for all those cases where you are using Decorator to add functionality that's truly generic.  I strongly suggest you give this a try!

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• Web API, JavaScript, Chrome &amp; Cross-Origin Resource Sharing

  - by Brian Lanham

  The team spent much of the week working through this issues related to Chrome running on Windows 8 consuming cross-origin resources using Web API.  We thought it was resolved on day 2 but it resurfaced the next day.  We definitely resolved it today though.  I believe I do not fully understand the situation but I am going to explain what I know in an effort to help you avoid and/or resolve a similar issue. References We referenced many sources during our trial-and-error troubleshooting.  These are the links we reference in order of applicability to the solution: Zoiner Tejada JavaScript and other material from -> http://www.devproconnections.com/content1/topic/microsoft-azure-cors-141869/catpath/windows-azure-platform2/page/3 WebDAV Where I learned about “Accept” –>  http://www-jo.se/f.pfleger/cors-and-iis? IT Hit Tells about NOT using ‘*’ –> http://www.webdavsystem.com/ajax/programming/cross_origin_requests Carlos Figueira Sample back-end code (newer) –> http://code.msdn.microsoft.com/windowsdesktop/Implementing-CORS-support-a677ab5d (older version) –> http://code.msdn.microsoft.com/CORS-support-in-ASPNET-Web-01e9980a   Background As a measure of protection, Web designers (W3C) and implementers (Google, Microsoft, Mozilla) made it so that a request, especially a JSON request (but really any URL), sent from one domain to another will only work if the requestee “knows” about the requester and allows requests from it. So, for example, if you write a ASP.NET MVC Web API service and try to consume it from multiple apps, the browsers used may (will?) indicate that you are not allowed by showing an “Access-Control-Allow-Origin” error indicating the requester is not allowed to make requests. Internet Explorer (big surprise) is the odd-hair-colored step-child in this mix. It seems that running locally at least IE allows this for development purposes.  Chrome and Firefox do not.  In fact, Chrome is quite restrictive.  Notice the images below. IE shows data (a tabular view with one row for each day of a week) while Chrome does not (trust me, neither does Firefox).  Further, the Chrome developer console shows an XmlHttpRequest (XHR) error. Screen captures from IE (left) and Chrome (right). Note that Chrome does not display data and the console shows an XHR error. Why does this happen? The Web browser submits these requests and processes the responses and each browser is different. Okay, so, IE is probably the only one that’s truly different.  However, Chrome has a specific process of performing a “pre-flight” check to make sure the service can respond to an “Access-Control-Allow-Origin” or Cross-Origin Resource Sharing (CORS) request.  So basically, the sequence is, if I understand correctly:  1)Page Loads –> 2)JavaScript Request Processed by Browser –> 3)Browsers Prepares to Submit Request –> 4)[Chrome] Browser Submits Pre-Flight Request –> 5)Server Responds with HTTP 200 –> 6)Browser Submits Request –> 7)Server Responds with Data –> 8)Page Shows Data This situation occurs for both GET and POST methods.  Typically, GET methods are called with query string parameters so there is no data posted.  Instead, the requesting domain needs to be permitted to request data but generally nothing more is required.  POSTs on the other hand send form data.  Therefore, more configuration is required (you’ll see the configuration below).  AJAX requests are not friendly with this (POSTs) either because they don’t post in a form. How to fix it. The team went through many iterations of self-hair removal and we think we finally have a working solution.  The trial-and-error approach eventually worked and we referenced many sources for the information.  I indicate those references above.  There are basically three (3) tasks needed to make this work. Assumptions: You are using Visual Studio, Web API, JavaScript, and have Cross-Origin Resource Sharing, and several browsers. 1. Configure the client Joel Cochran centralized our “cors-oriented” JavaScript (from here). There are two calls including one for GET and one for POST function(url, data, callback) {             console.log(data);             $.support.cors = true;             var jqxhr = $.post(url, data, callback, "json")                 .error(function(jqXhHR, status, errorThrown) {                     if ($.browser.msie && window.XDomainRequest) {                         var xdr = new XDomainRequest();                         xdr.open("post", url);                         xdr.onload = function () {                             if (callback) {                                 callback(JSON.parse(this.responseText), 'success');                             }                         };                         xdr.send(data);                     } else {                         console.log(">" + jqXhHR.status);                         alert("corsAjax.post error: " + status + ", " + errorThrown);                     }                 });         }; The GET CORS JavaScript function (credit to Zoiner Tejada) function(url, callback) {             $.support.cors = true;             var jqxhr = $.get(url, null, callback, "json")                 .error(function(jqXhHR, status, errorThrown) {                     if ($.browser.msie && window.XDomainRequest) {                         var xdr = new XDomainRequest();                         xdr.open("get", url);                         xdr.onload = function () {                             if (callback) {                                 callback(JSON.parse(this.responseText), 'success');                             }                         };                         xdr.send();                     } else {                         alert("CORS is not supported in this browser or from this origin.");                     }                 });         }; The POST CORS JavaScript function (credit to Zoiner Tejada) Now you need to call these functions to get and post your data (instead of, say, using $.Ajax). Here is a GET example: corsAjax.get(url, function(data) { if (data !== null && data.length !== undefined) { // do something with data } }); And here is a POST example: corsAjax.post(url, item); Simple…except…you’re not done yet. 2. Change Web API Controllers to Allow CORS There are actually two steps here.  Do you remember above when we mentioned the “pre-flight” check?  Chrome actually asks the server if it is allowed to ask it for cross-origin resource sharing access.  So you need to let the server know it’s okay.  This is a two-part activity.  a) Add the appropriate response header Access-Control-Allow-Origin, and b) permit the API functions to respond to various methods including GET, POST, and OPTIONS.  OPTIONS is the method that Chrome and other browsers use to ask the server if it can ask about permissions.  Here is an example of a Web API controller thus decorated: NOTE: You’ll see a lot of references to using “*” in the header value.  For security reasons, Chrome does NOT recognize this is valid. [HttpHeader("Access-Control-Allow-Origin", "http://localhost:51234")] [HttpHeader("Access-Control-Allow-Credentials", "true")] [HttpHeader("Access-Control-Allow-Methods", "ACCEPT, PROPFIND, PROPPATCH, COPY, MOVE, DELETE, MKCOL, LOCK, UNLOCK, PUT, GETLIB, VERSION-CONTROL, CHECKIN, CHECKOUT, UNCHECKOUT, REPORT, UPDATE, CANCELUPLOAD, HEAD, OPTIONS, GET, POST")] [HttpHeader("Access-Control-Allow-Headers", "Accept, Overwrite, Destination, Content-Type, Depth, User-Agent, X-File-Size, X-Requested-With, If-Modified-Since, X-File-Name, Cache-Control")] [HttpHeader("Access-Control-Max-Age", "3600")] public abstract class BaseApiController : ApiController {     [HttpGet]     [HttpOptions]     public IEnumerable<foo> GetFooItems(int id)     {         return foo.AsEnumerable();     }     [HttpPost]     [HttpOptions]     public void UpdateFooItem(FooItem fooItem)     {         // NOTE: The fooItem object may or may not         // (probably NOT) be set with actual data.         // If not, you need to extract the data from         // the posted form manually.         if (fooItem.Id == 0) // However you check for default...         {             // We use NewtonSoft.Json.             string jsonString = context.Request.Form.GetValues(0)[0].ToString();             Newtonsoft.Json.JsonSerializer js = new Newtonsoft.Json.JsonSerializer();             fooItem = js.Deserialize<FooItem>(new Newtonsoft.Json.JsonTextReader(new System.IO.StringReader(jsonString)));         }         // Update the set fooItem object.     } } Please note a few specific additions here: * The header attributes at the class level are required.  Note all of those methods and headers need to be specified but we find it works this way so we aren’t touching it. * Web API will actually deserialize the posted data into the object parameter of the called method on occasion but so far we don’t know why it does and doesn’t. * [HttpOptions] is, again, required for the pre-flight check. * The “Access-Control-Allow-Origin” response header should NOT NOT NOT contain an ‘*’. 3. Headers and Methods and Such We had most of this code in place but found that Chrome and Firefox still did not render the data.  Interestingly enough, Fiddler showed that the GET calls succeeded and the JSON data is returned properly.  We learned that among the headers set at the class level, we needed to add “ACCEPT”.  Note that I accidentally added it to methods and to headers.  Adding it to methods worked but I don’t know why.  We added it to headers also for good measure. [HttpHeader("Access-Control-Allow-Methods", "ACCEPT, PROPFIND, PROPPA... [HttpHeader("Access-Control-Allow-Headers", "Accept, Overwrite, Destin... Next Steps That should do it.  If it doesn’t let us know.  What to do next?  * Don’t hardcode the allowed domains.  Note that port numbers and other domain name specifics will cause problems and must be specified.  If this changes do you really want to deploy updated software?  Consider Miguel Figueira’s approach in the following link to writing a custom HttpHeaderAttribute class that allows you to specify the domain names and then you can do it dynamically.  There are, of course, other ways to do it dynamically but this is a clean approach. http://code.msdn.microsoft.com/windowsdesktop/Implementing-CORS-support-a677ab5d

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• GZip/Deflate Compression in ASP.NET MVC

  - by Rick Strahl

  A long while back I wrote about GZip compression in ASP.NET. In that article I describe two generic helper methods that I've used in all sorts of ASP.NET application from WebForms apps to HttpModules and HttpHandlers that require gzip or deflate compression. The same static methods also work in ASP.NET MVC. Here are the two routines:/// <summary> /// Determines if GZip is supported /// </summary> /// <returns></returns> public static bool IsGZipSupported() { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (!string.IsNullOrEmpty(AcceptEncoding) && (AcceptEncoding.Contains("gzip") || AcceptEncoding.Contains("deflate"))) return true; return false; } /// <summary> /// Sets up the current page or handler to use GZip through a Response.Filter /// IMPORTANT: /// You have to call this method before any output is generated! /// </summary> public static void GZipEncodePage() { HttpResponse Response = HttpContext.Current.Response; if (IsGZipSupported()) { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (AcceptEncoding.Contains("gzip")) { Response.Filter = new System.IO.Compression.GZipStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); Response.Headers.Remove("Content-Encoding"); Response.AppendHeader("Content-Encoding", "gzip"); } else { Response.Filter = new System.IO.Compression.DeflateStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); Response.Headers.Remove("Content-Encoding"); Response.AppendHeader("Content-Encoding", "deflate"); } } // Allow proxy servers to cache encoded and unencoded versions separately Response.AppendHeader("Vary", "Content-Encoding"); } The first method checks whether the client sending the request includes the accept-encoding for either gzip or deflate, and if if it does it returns true. The second function uses IsGzipSupported() to decide whether it should encode content and uses an Response Filter to do its job. Basically response filters look at the Response output stream as it's written and convert the data flowing through it. Filters are a bit tricky to work with but the two .NET filter streams for GZip and Deflate Compression make this a snap to implement. In my old code and even now in MVC I can always do:public ActionResult List(string keyword=null, int category=0) { WebUtils.GZipEncodePage(); …} to encode my content. And that works just fine. The proper way: Create an ActionFilterAttribute However in MVC this sort of thing is typically better handled by an ActionFilter which can be applied with an attribute. So to be all prim and proper I created an CompressContentAttribute ActionFilter that incorporates those two helper methods and which looks like this:/// <summary> /// Attribute that can be added to controller methods to force content /// to be GZip encoded if the client supports it /// </summary> public class CompressContentAttribute : ActionFilterAttribute { /// <summary> /// Override to compress the content that is generated by /// an action method. /// </summary> /// <param name="filterContext"></param> public override void OnActionExecuting(ActionExecutingContext filterContext) { GZipEncodePage(); } /// <summary> /// Determines if GZip is supported /// </summary> /// <returns></returns> public static bool IsGZipSupported() { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (!string.IsNullOrEmpty(AcceptEncoding) && (AcceptEncoding.Contains("gzip") || AcceptEncoding.Contains("deflate"))) return true; return false; } /// <summary> /// Sets up the current page or handler to use GZip through a Response.Filter /// IMPORTANT: /// You have to call this method before any output is generated! /// </summary> public static void GZipEncodePage() { HttpResponse Response = HttpContext.Current.Response; if (IsGZipSupported()) { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (AcceptEncoding.Contains("gzip")) { Response.Filter = new System.IO.Compression.GZipStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); Response.Headers.Remove("Content-Encoding"); Response.AppendHeader("Content-Encoding", "gzip"); } else { Response.Filter = new System.IO.Compression.DeflateStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); Response.Headers.Remove("Content-Encoding"); Response.AppendHeader("Content-Encoding", "deflate"); } } // Allow proxy servers to cache encoded and unencoded versions separately Response.AppendHeader("Vary", "Content-Encoding"); } } It's basically the same code wrapped into an ActionFilter attribute, which intercepts requests MVC requests to Controller methods and lets you hook up logic before and after the methods have executed. Here I want to override OnActionExecuting() which fires before the Controller action is fired. With the CompressContentAttribute created, it can now be applied to either the controller as a whole:[CompressContent] public class ClassifiedsController : ClassifiedsBaseController { … } or to one of the Action methods:[CompressContent] public ActionResult List(string keyword=null, int category=0) { … } The former applies compression to every action method, while the latter is selective and only applies it to the individual action method. Is the attribute better than the static utility function? Not really, but it is the standard MVC way to hook up 'filter' content and that's where others are likely to expect to set options like this. In fact,  you have a bit more control with the utility function because you can conditionally apply it in code, but this is actually much less likely in MVC applications than old WebForms apps since controller methods tend to be more focused. Compression Caveats Http compression is very cool and pretty easy to implement in ASP.NET but you have to be careful with it - especially if your content might get transformed or redirected inside of ASP.NET. A good example, is if an error occurs and a compression filter is applied. ASP.NET errors don't clear the filter, but clear the Response headers which results in some nasty garbage because the compressed content now no longer matches the headers. Another issue is Caching, which has to account for all possible ways of compression and non-compression that the content is served. Basically compressed content and caching don't mix well. I wrote about several of these issues in an old blog post and I recommend you take a quick peek before diving into making every bit of output Gzip encoded. None of these are show stoppers, but you have to be aware of the issues. Related Posts GZip Compression with ASP.NET Content ASP.NET GZip Encoding Caveats© Rick Strahl, West Wind Technologies, 2005-2012Posted in ASP.NET  MVC   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• How to properly add .NET assemblies to Powershell session?

  - by amandion

  I have a .NET assembly (a dll) which is an API to backup software we use here. It contains some properties and methods I would like to take advantage of in my Powershell script(s). However, I am running into a lot of issues with first loading the assembly, then using any of the types once the assembly is loaded. The complete file path is: C:\rnd\CloudBerry.Backup.API.dll In Powershell I use: $dllpath = "C:\rnd\CloudBerry.Backup.API.dll" Add-Type -Path $dllpath I get the error below: Add-Type : Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information. At line:1 char:9 + Add-Type <<<< -Path $dllpath + CategoryInfo : NotSpecified: (:) [Add-Type], ReflectionTypeLoadException + FullyQualifiedErrorId : System.Reflection.ReflectionTypeLoadException,Microsoft.PowerShell.Commands.AddTypeComma ndAdd-Type : Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information. Using the same cmdlet on another .NET assembly, DotNetZip, which has examples of using the same functionality on the site also does not work for me. I eventually find that I am seemingly able to load the assembly using reflection: [System.Reflection.Assembly]::LoadFrom($dllpath) Although I don't understand the difference between the methods Load, LoadFrom, or LoadFile that last method seems to work. However, I still seem to be unable to create instances or use objects. Each time I try, I get errors that describe that Powershell is unable to find any of the public types. I know the classes are there: $asm = [System.Reflection.Assembly]::LoadFrom($dllpath) $cbbtypes = $asm.GetExportedTypes() $cbbtypes | Get-Member -Static ---- start of excerpt ---- TypeName: CloudBerryLab.Backup.API.BackupProvider Name MemberType Definition ---- ---------- ---------- PlanChanged Event System.EventHandler`1[CloudBerryLab.Backup.API.Utils.ChangedEventArgs] PlanChanged(Sy... PlanRemoved Event System.EventHandler`1[CloudBerryLab.Backup.API.Utils.PlanRemoveEventArgs] PlanRemoved... CalculateFolderSize Method static long CalculateFolderSize() Equals Method static bool Equals(System.Object objA, System.Object objB) GetAccounts Method static CloudBerryLab.Backup.API.Account[], CloudBerry.Backup.API, Version=1.0.0.1, Cu... GetBackupPlans Method static CloudBerryLab.Backup.API.BackupPlan[], CloudBerry.Backup.API, Version=1.0.0.1,... ReferenceEquals Method static bool ReferenceEquals(System.Object objA, System.Object objB) SetProfilePath Method static System.Void SetProfilePath(string profilePath) ----end of excerpt---- Trying to use static methods fail, I don't know why!!! [CloudBerryLab.Backup.API.BackupProvider]::GetAccounts() Unable to find type [CloudBerryLab.Backup.API.BackupProvider]: make sure that the assembly containing this type is load ed. At line:1 char:42 + [CloudBerryLab.Backup.API.BackupProvider] <<<< ::GetAccounts() + CategoryInfo : InvalidOperation: (CloudBerryLab.Backup.API.BackupProvider:String) [], RuntimeException + FullyQualifiedErrorId : TypeNotFound Any guidance appreciated!!

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• VirtualBox 4.1.12 Ubuntu Host Bridged Networking

  - by hidden_premise

  Setup Ubuntu Server 11.10 x64 VirtualBox 4.1.12 One network adapter eth0 with a static IP address My /etc/network/interfaces looks like #Local loopback auto lo iface lo inet loopback #Primary Interface auto eth0 iface eth0 inet static address 10.0.0.6 netmask 255.255.255.0 gateway 10.0.0.1 Need Static IP for Ubuntu Host Static IP for multiple Ubuntu guests My attempt Downloaded the .deb for 64bit virtual box dpkg -i virtualbox.deb Create a VM and install ubuntu server 11.10 x64 from ISO Set the networking mode to bridged and choose 'eth0' as the interface Fail. None of the guides I can find for bridged networking work because everything changed since vbox 2

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• How to configure a hostname of sub-application?

  - by BrunoLM

  I have a structure like this: Website |- Controllers |- Models |- Views |- Content |- Static (APP) Website is an application using an ASP.NET 4.0 pool. Static is a sub-application using a not managed application pool. On Website bindings I've set local.domain.com to have access through port 80. I want to access the Static app using static.domain.com, but I don't find the option to configure the binding. How is it possible to configure like that?

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• ASP.NET webforms + ASP.NET Ajax versus ASP.NET MVC and Ajax framework freedom

  - by public static

  If given the choice, which path would you take? ASP.NET Webforms + ASP.NET AJAX or ASP.NET MVC + JavaScript Framework of your Choice Are there any limitations that ASP.NET Webforms / ASP.NET AJAX has vis-a-vis MVC?

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• Django CMS - not able to upload images through cmsplugin_filer_image

  - by Luke

  i have a problem with a local installation on django cms 2.3.3: i've installed it trough pip, in a separated virtualenv. next i followed the tutorial for settings.py configuration, i started the server. Then in the admin i created an page (home), and i've tried to add an image in the placeholder through the cmsplugin_filer_image, but the upload seems that doesn't work. here's my settings.py: # Django settings for cms1 project. # -*- coding: utf-8 -*- import os gettext = lambda s: s PROJECT_PATH = os.path.abspath(os.path.dirname(__file__)) DEBUG = True TEMPLATE_DEBUG = DEBUG ADMINS = ( # ('Your Name', '[email protected]'), ) MANAGERS = ADMINS DATABASES = { 'default': { 'ENGINE': 'django.db.backends.postgresql_psycopg2', # Add 'postgresql_psycopg2', 'mysql', 'sqlite3' or 'oracle'. 'NAME': 'cms1', # Or path to database file if using sqlite3. 'USER': 'cms', # Not used with sqlite3. 'PASSWORD': 'cms', # Not used with sqlite3. 'HOST': '', # Set to empty string for localhost. Not used with sqlite3. 'PORT': '', # Set to empty string for default. Not used with sqlite3. } } # Local time zone for this installation. Choices can be found here: # http://en.wikipedia.org/wiki/List_of_tz_zones_by_name # although not all choices may be available on all operating systems. # In a Windows environment this must be set to your system time zone. TIME_ZONE = 'Europe/Rome' # Language code for this installation. All choices can be found here: # http://www.i18nguy.com/unicode/language-identifiers.html LANGUAGE_CODE = 'it-it' SITE_ID = 1 # If you set this to False, Django will make some optimizations so as not # to load the internationalization machinery. USE_I18N = True # If you set this to False, Django will not format dates, numbers and # calendars according to the current locale. USE_L10N = True # If you set this to False, Django will not use timezone-aware datetimes. USE_TZ = True # Absolute filesystem path to the directory that will hold user-uploaded files. # Example: "/home/media/media.lawrence.com/media/" MEDIA_ROOT = os.path.join(PROJECT_PATH, "media") # URL that handles the media served from MEDIA_ROOT. Make sure to use a # trailing slash. # Examples: "http://media.lawrence.com/media/", "http://example.com/media/" MEDIA_URL = '/media/' # Absolute path to the directory static files should be collected to. # Don't put anything in this directory yourself; store your static files # in apps' "static/" subdirectories and in STATICFILES_DIRS. # Example: "/home/media/media.lawrence.com/static/" STATIC_ROOT = os.path.join(PROJECT_PATH, "static") STATIC_URL = "/static/" # Additional locations of static files STATICFILES_DIRS = ( os.path.join(PROJECT_PATH, "static_auto"), # Put strings here, like "/home/html/static" or "C:/www/django/static". # Always use forward slashes, even on Windows. # Don't forget to use absolute paths, not relative paths. ) # List of finder classes that know how to find static files in # various locations. STATICFILES_FINDERS = ( 'django.contrib.staticfiles.finders.FileSystemFinder', 'django.contrib.staticfiles.finders.AppDirectoriesFinder', # 'django.contrib.staticfiles.finders.DefaultStorageFinder', ) # Make this unique, and don't share it with anybody. SECRET_KEY = '^c2q3d8w)f#gk%5i)(#i*lwt%lm-!2=(*1d!1cf+rg&amp;-hqi_9u' # List of callables that know how to import templates from various sources. TEMPLATE_LOADERS = ( 'django.template.loaders.filesystem.Loader', 'django.template.loaders.app_directories.Loader', # 'django.template.loaders.eggs.Loader', ) MIDDLEWARE_CLASSES = ( 'django.middleware.common.CommonMiddleware', 'django.contrib.sessions.middleware.SessionMiddleware', 'django.middleware.csrf.CsrfViewMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware', 'django.contrib.messages.middleware.MessageMiddleware', 'cms.middleware.multilingual.MultilingualURLMiddleware', 'cms.middleware.page.CurrentPageMiddleware', 'cms.middleware.user.CurrentUserMiddleware', 'cms.middleware.toolbar.ToolbarMiddleware', # Uncomment the next line for simple clickjacking protection: # 'django.middleware.clickjacking.XFrameOptionsMiddleware', ) ROOT_URLCONF = 'cms1.urls' # Python dotted path to the WSGI application used by Django's runserver. WSGI_APPLICATION = 'cms1.wsgi.application' TEMPLATE_DIRS = ( os.path.join(PROJECT_PATH, "templates"), # Put strings here, like "/home/html/django_templates" or "C:/www/django/templates". # Always use forward slashes, even on Windows. # Don't forget to use absolute paths, not relative paths. ) CMS_TEMPLATES = ( ('template_1.html', 'Template One'), ('template_2.html', 'Template Two'), ) TEMPLATE_CONTEXT_PROCESSORS = ( 'django.contrib.auth.context_processors.auth', 'django.core.context_processors.i18n', 'django.core.context_processors.request', 'django.core.context_processors.media', 'django.core.context_processors.static', 'cms.context_processors.media', 'sekizai.context_processors.sekizai', ) LANGUAGES = [ ('it', 'Italiano'), ('en', 'English'), ] INSTALLED_APPS = ( 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.sites', 'django.contrib.messages', 'django.contrib.staticfiles', 'cms', #django CMS itself 'mptt', #utilities for implementing a modified pre-order traversal tree 'menus', #helper for model independent hierarchical website navigation 'south', #intelligent schema and data migrations 'sekizai', #for javascript and css management #'cms.plugins.file', 'cms.plugins.flash', 'cms.plugins.googlemap', 'cms.plugins.link', #'cms.plugins.picture', 'cms.plugins.snippet', 'cms.plugins.teaser', 'cms.plugins.text', #'cms.plugins.video', 'cms.plugins.twitter', 'filer', 'cmsplugin_filer_file', 'cmsplugin_filer_folder', 'cmsplugin_filer_image', 'cmsplugin_filer_teaser', 'cmsplugin_filer_video', 'easy_thumbnails', 'PIL', # Uncomment the next line to enable the admin: 'django.contrib.admin', # Uncomment the next line to enable admin documentation: # 'django.contrib.admindocs', ) # A sample logging configuration. The only tangible logging # performed by this configuration is to send an email to # the site admins on every HTTP 500 error when DEBUG=False. # See http://docs.djangoproject.com/en/dev/topics/logging for # more details on how to customize your logging configuration. LOGGING = { 'version': 1, 'disable_existing_loggers': False, 'filters': { 'require_debug_false': { '()': 'django.utils.log.RequireDebugFalse' } }, 'handlers': { 'mail_admins': { 'level': 'ERROR', 'filters': ['require_debug_false'], 'class': 'django.utils.log.AdminEmailHandler' } }, 'loggers': { 'django.request': { 'handlers': ['mail_admins'], 'level': 'ERROR', 'propagate': True, }, } } when i try to upload an image, in the clipboard section i don't have the thumbnail, but just an 'undefined' message: and this is the runserver console while trying to upload: [20/Oct/2012 15:15:56] "POST /admin/filer/clipboard/operations/upload/?qqfile=29708_1306856312320_7706073_n.jpg HTTP/1.1" 500 248133 [20/Oct/2012 15:15:56] "GET /it/admin/filer/folder/unfiled_images/undefined HTTP/1.1" 301 0 [20/Oct/2012 15:15:56] "GET /it/admin/filer/folder/unfiled_images/undefined/ HTTP/1.1" 404 1739 Also, this is project filesystem: cms1 +-- cms1 ¦   +-- __init__.py ¦   +-- __init__.pyc ¦   +-- media ¦   ¦   +-- filer_public ¦   ¦   +-- 2012 ¦   ¦   +-- 10 ¦   ¦   +-- 20 ¦   ¦   +-- 29708_1306856312320_7706073_n_1.jpg ¦   ¦   +-- 29708_1306856312320_7706073_n_2.jpg ¦   ¦   +-- 29708_1306856312320_7706073_n_3.jpg ¦   ¦   +-- 29708_1306856312320_7706073_n_4.jpg ¦   ¦   +-- 29708_1306856312320_7706073_n_5.jpg ¦   ¦   +-- 29708_1306856312320_7706073_n_6.jpg ¦   ¦   +-- 29708_1306856312320_7706073_n_7.jpg ¦   ¦   +-- 29708_1306856312320_7706073_n.jpg ¦   ¦   +-- torrent-client-macosx.jpg ¦   +-- settings.py ¦   +-- settings.pyc ¦   +-- static ¦   +-- static_auto ¦   +-- static_manual ¦   +-- templates ¦   ¦   +-- base.html ¦   ¦   +-- template_1.html ¦   ¦   +-- template_2.html ¦   +-- urls.py ¦   +-- urls.pyc ¦   +-- wsgi.py ¦   +-- wsgi.pyc +-- manage.py So files are uploaded, but they are not accessible to cms. there's a similar question here, but doens't help me so much. It would be very helpful any help on this issue to me. Thanks, luke

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• CheckBox Command Behaviors for Silverlight MVVM Pattern

  - by Blake Blackwell

  I am trying to detect when an item is checked, and which item is checked in a ListBox using Silverlight 4 and the Prism framework. I found this example on creating behaviors, and tried to follow it but nothing is happening in the debugger. I have three questions: Why isn't my command executing? How do I determine which item was checked (i.e. pass a command parameter)? How do I debug this? (i.e. where can I put break points to begin stepping into this) Here is my code: View: <ListBox x:Name="MyListBox" ItemsSource="{Binding PanelItems, Mode=TwoWay}"> <ListBox.ItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal"> <CheckBox IsChecked="{Binding Enabled}" my:Checked.Command="{Binding Check}" /> <TextBlock x:Name="DisplayName" Text="{Binding DisplayName}"/> </StackPanel> </DataTemplate> </ListBox.ItemTemplate> </ListBox> ViewModel: public MainPageViewModel() { _panelItems.Add( new PanelItem { Enabled = true, DisplayName = "Test1" } ); Check = new DelegateCommand<object>( itemChecked ); } public void itemChecked( object o ) { //do some stuff } public DelegateCommand<object> Check { get; set; } Behavior Class public class CheckedBehavior : CommandBehaviorBase<CheckBox> { public CheckedBehavior( CheckBox element ) : base( element ) { element.Checked +=new RoutedEventHandler(element_Checked); } void element_Checked( object sender, RoutedEventArgs e ) { base.ExecuteCommand(); } } Command Class public static class Checked { public static ICommand GetCommand( DependencyObject obj ) { return (ICommand) obj.GetValue( CommandProperty ); } public static void SetCommand( DependencyObject obj, ICommand value ) { obj.SetValue( CommandProperty, value ); } public static readonly DependencyProperty CommandProperty = DependencyProperty.RegisterAttached( "Command", typeof( CheckBox ), typeof( Checked ), new PropertyMetadata( OnSetCommandCallback ) ); public static readonly DependencyProperty CheckedCommandBehaviorProperty = DependencyProperty.RegisterAttached( "CheckedCommandBehavior", typeof( CheckedBehavior ), typeof( Checked ), null ); private static void OnSetCommandCallback( DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e ) { CheckBox element = dependencyObject as CheckBox; if( element != null ) { CheckedBehavior behavior = GetOrCreateBehavior( element ); behavior.Command = e.NewValue as ICommand; } } private static CheckedBehavior GetOrCreateBehavior( CheckBox element ) { CheckedBehavior behavior = element.GetValue( CheckedCommandBehaviorProperty ) as CheckedBehavior; if( behavior == null ) { behavior = new CheckedBehavior( element ); element.SetValue( CheckedCommandBehaviorProperty, behavior ); } return behavior; } public static CheckedBehavior GetCheckCommandBehavior( DependencyObject obj ) { return (CheckedBehavior) obj.GetValue( CheckedCommandBehaviorProperty ); } public static void SetCheckCommandBehavior( DependencyObject obj, CheckedBehavior value ) { obj.SetValue( CheckedCommandBehaviorProperty, value ); } } I used this article to get me started, but I'll readily admit this is over my head.

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• Camera Preview App in Android throwing many errors (Nexus 4)

  - by Jagatheesan Jack

  I am trying to develop a camera app that takes a picture and saves it in a SQLite database. I get a lot of errors when executing the application. My code is as below. Any idea? CameraActivity.java private Camera mCamera; private CameraPreview mPreview; private int CAMERA_RETURN_CODE=100; private static final String TAG = "Take_Picture"; public static final int MEDIA_TYPE_IMAGE = 1; public static final int MEDIA_TYPE_VIDEO = 2; private Bitmap cameraBmp; private int MAX_FACES = 1; private Face[] faceList; public RectF[] rects; private Canvas canvas; private Drawable pictureDataDrawable; private MySQLiteHelper database; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.camera_activity); //this.requestWindowFeature(Window.FEATURE_NO_TITLE); //Create an instance of Camera mCamera = getCameraInstance(); setCameraDisplayOrientation(this, 0, mCamera); // Create our Preview view and set it as the content of our activity. mPreview = new CameraPreview(this, mCamera); FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview); preview.addView(mPreview); database = new MySQLiteHelper(getApplicationContext()); Button captureButton = (Button) findViewById(R.id.button_capture); captureButton.setOnClickListener( new View.OnClickListener() { private PictureCallback mPicture; @Override public void onClick(View v) { //mCamera.startPreview(); // get an image from the camera mCamera.takePicture(null, null, mPicture); PictureCallback mPicture = new PictureCallback() { @Override public void onPictureTaken(byte[] data, Camera camera) { try{ if (data != null) database.addEntry(data); //mCamera.startPreview(); } catch(Exception e){ Log.d(TAG, e.getMessage()); } } } ); } /** A safe way to get an instance of the Camera object. */ public static Camera getCameraInstance(){ Camera c = null; try { c = Camera.open(c.getNumberOfCameras()-1); // attempt to get a Camera instance } catch (Exception e){ // Camera is not available (in use or does not exist) } return c; // returns null if camera is unavailable } public static void setCameraDisplayOrientation(Activity activity, int cameraId, android.hardware.Camera camera) { android.hardware.Camera.CameraInfo info = new android.hardware.Camera.CameraInfo(); android.hardware.Camera.getCameraInfo(cameraId, info); int rotation = activity.getWindowManager().getDefaultDisplay() .getRotation(); int degrees = 360; /*switch (rotation) { case Surface.ROTATION_0: degrees = 0; break; case Surface.ROTATION_90: degrees = 90; break; case Surface.ROTATION_180: degrees = 180; break; case Surface.ROTATION_270: degrees = 270; break; }*/ int result; if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) { result = (info.orientation + degrees) % 360; result = (360 - result) % 360; // compensate the mirror } else { // back-facing result = (info.orientation - degrees + 360) % 360; } camera.setDisplayOrientation(result); } @Override protected void onPause() { super.onPause(); //releaseMediaRecorder(); // if you are using MediaRecorder, release it first releaseCamera(); // release the camera immediately on pause event } private void releaseCamera(){ if (mCamera != null){ mCamera.release(); // release the camera for other applications mCamera = null; } } public void startFaceDetection(){ // Try starting Face Detection Camera.Parameters params = mCamera.getParameters(); // start face detection only *after* preview has started if (params.getMaxNumDetectedFaces() > 0){ // camera supports face detection, so can start it: mCamera.startFaceDetection(); } } CameraPreview.java public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback { private SurfaceHolder mHolder; private Camera mCamera; private String TAG; private List<Size> mSupportedPreviewSizes; public CameraPreview(Context context, Camera camera) { super(context); mCamera = camera; // Install a SurfaceHolder.Callback so we get notified when the // underlying surface is created and destroyed. mHolder = getHolder(); mHolder.addCallback(this); // deprecated setting, but required on Android versions prior to 3.0 mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } public void surfaceCreated(SurfaceHolder holder) { // The Surface has been created, now tell the camera where to draw the preview. try { mCamera.setPreviewDisplay(holder); mCamera.setDisplayOrientation(90); mCamera.startPreview(); } catch (IOException e) { Log.d(TAG, "Error setting camera preview: " + e.getMessage()); } } public void surfaceDestroyed(SurfaceHolder holder) { // empty. Take care of releasing the Camera preview in your activity. } public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { // If your preview can change or rotate, take care of those events here. // Make sure to stop the preview before resizing or reformatting it. if (mHolder.getSurface() == null){ // preview surface does not exist return; } // stop preview before making changes try { mCamera.stopPreview(); } catch (Exception e){ // ignore: tried to stop a non-existent preview } try { mCamera.setPreviewDisplay(mHolder); mCamera.startPreview(); } catch (Exception e){ Log.d(TAG, "Error starting camera preview: " + e.getMessage()); } } public void setCamera(Camera camera) { if (mCamera == camera) { return; } mCamera = camera; if (mCamera != null) { List<Size> localSizes = mCamera.getParameters().getSupportedPreviewSizes(); mSupportedPreviewSizes = localSizes; requestLayout(); try { mCamera.setPreviewDisplay(mHolder); } catch (IOException e) { e.printStackTrace(); } /* Important: Call startPreview() to start updating the preview surface. Preview must be started before you can take a picture. */ mCamera.startPreview(); } } MySQLiteHelper.java private static final int count = 0; public static final String TABLE_IMAGE = "images"; public static final String COLUMN_ID = "_id"; public static final String PICTURE_DATA = "picture"; public static final String DATABASE_NAME = "images.db"; public static final int DATABASE_VERSION = 1; public static final String DATABASE_CREATE = "create table " + TABLE_IMAGE + "(" + COLUMN_ID + " integer primary key autoincrement, " + PICTURE_DATA + " blob not null);"; public static SQLiteDatabase database; private static String TAG = "test"; public MySQLiteHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); // TODO Auto-generated constructor stub } public MySQLiteHelper(Context context, String name, CursorFactory factory, int version, DatabaseErrorHandler errorHandler) { super(context, name, factory, version, errorHandler); // TODO Auto-generated constructor stub } @Override public void onCreate(SQLiteDatabase database) { database.execSQL(DATABASE_CREATE); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { Log.w(MySQLiteHelper.class.getName(), "Upgrading database from version " + oldVersion + " to " + newVersion + ", which will destroy all old data"); db.execSQL("DROP TABLE IF EXISTS " + TABLE_IMAGE); onCreate(db); } /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub } public void addEntry(byte [] array) throws SQLiteException{ ContentValues cv = new ContentValues(); //cv.put(KEY_NAME, name); cv.put(PICTURE_DATA, array); database.insert( TABLE_IMAGE, null, cv ); Log.w(TAG , "added " +count+ "images"); database.close(); } Errors 11-07 23:28:39.050: E/mm-libcamera2(176): PROFILE HAL: stopPreview(): E: 1383838119.067589459 11-07 23:28:39.050: E/mm-camera(201): config_MSG_ID_STOP_ACK: streamon_mask is not clear. Should not call PP_Release_HW 11-07 23:28:39.090: E/QCameraHWI(176): android::status_t android::QCameraHardwareInterface::setPreviewWindow(preview_stream_ops_t*):Received Setting NULL preview window 11-07 23:28:39.090: E/QCameraHWI(176): android::status_t android::QCameraHardwareInterface::setPreviewWindow(preview_stream_ops_t*): mPreviewWindow = 0x0x0, mStreamDisplay = 0x0xb8a9df90 11-07 23:28:39.090: E/mm-camera(201): config_shutdown_pp Camera not in streaming mode. Returning. 11-07 23:28:39.090: E/mm-camera(201): vfe_ops_deinit: E 11-07 23:28:39.120: E/qcom_sensors_hal(533): hal_process_report_ind: Bad item quality: 11 11-07 23:28:39.310: E/qcom_sensors_hal(533): hal_process_report_ind: Bad item quality: 11 11-07 23:28:39.330: E/mm-camera(201): sensor_load_chromatix: libchromatix_imx119_preview.so: 30 11-07 23:28:39.340: E/mm-camera(201): vfe_ops_init: E 11-07 23:28:39.360: E/mm-camera(201): vfe_legacy_stats_buffer_init: AEC_STATS_BUFNUM 11-07 23:28:39.360: E/mm-camera(201): vfe_legacy_stats_buffer_init: AEC_STATS_BUFNUM 11-07 23:28:39.360: E/mm-camera(201): mctl_init_stats_proc_info: snap_max_line_cnt =25776 11-07 23:28:39.440: E/QCameraHWI(176): android::status_t android::QCameraHardwareInterface::setPreviewWindow(preview_stream_ops_t*): mPreviewWindow = 0x0xb8aa1780, mStreamDisplay = 0x0xb8a9df90 11-07 23:28:39.440: E/mm-camera(201): config_proc_CAMERA_SET_INFORM_STARTPREVIEW 11-07 23:28:39.450: E/mm-camera(201): config_update_stream_info Storing stream parameters for video inst 1 as : width = 640, height 480, format = 1 inst_handle = 810081 cid = 0 11-07 23:28:39.490: E/mm-camera(201): config_update_stream_info Storing stream parameters for video inst 3 as : width = 640, height 480, format = 1 inst_handle = 830083 cid = 0 11-07 23:28:39.490: E/mm-camera(201): config_update_stream_info Storing stream parameters for video inst 4 as : width = 512, height 384, format = 1 inst_handle = 840084 cid = 0 11-07 23:28:39.500: E/mm-camera(201): config_decide_vfe_outputs: Ports Used 3, Op mode 1 11-07 23:28:39.500: E/mm-camera(201): config_decide_vfe_outputs Current mode 0 Full size streaming : Disabled 11-07 23:28:39.500: E/mm-camera(201): config_decide_vfe_outputs: Primary: 640x480, extra_pad: 0x0, Fmt: 1, Type: 1, Path: 1 11-07 23:28:39.500: E/mm-camera(201): config_decide_vfe_outputs: Secondary: 640x480, extra_pad: 0x0, Fmt: 1, Type: 3, Path: 4 11-07 23:28:39.510: E/mm-camera(201): config_update_inst_handles Updated the inst handles as 810081, 830083, 0, 0 11-07 23:28:39.631: E/mm-camera(201): sensor_load_chromatix: libchromatix_imx119_preview.so: 30 11-07 23:28:39.631: E/mm-camera(201): camif_client_set_params: camif has associated with obj mask 0x1 11-07 23:28:39.631: E/mm-camera(201): config_v2_CAMERA_START_common CAMIF_PARAMS_ADD_OBJ_ID failed -1 11-07 23:28:39.641: E/mm-camera(201): vfe_operation_config: format 3 11-07 23:28:39.641: E/mm-camera(201): vfe_operation_config:vfe_op_mode=5 11-07 23:28:39.641: E/mm-camera(201): Invalid ASD Set Params Type 11-07 23:28:39.641: E/mm-camera(201): vfe_set_bestshot: Bestshot mode not changed

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• Android never receives UDP packet

  - by Quandary

  The below code results in a timeout. It works fine on non-Android Java. What's the matter? //@Override public static void run() { //System.out.println ( "Local Machine IP : "+addrStr.toString ( ) ) ; HelloWorldActivity.tv.setText("Trace 1"); try { // Retrieve the ServerName InetAddress serverAddr; //= InetAddress.getByName(Server.SERVERIP); InetAddress ias[] = InetAddress.getAllByName(Server.SERVERNAME); serverAddr = ias[0]; Log.d("UDP", "C: Connecting..."); /* Create new UDP-Socket */ DatagramSocket socket = new DatagramSocket(); /* Prepare some data to be sent. */ String strQuery="ÿÿÿÿgetservers"+" "+Server.iProtocol+" "+"'all'"; Log.d("UDP", strQuery); //byte[] buf = ("ÿÿÿÿgetservers 68 'all'").getBytes(); byte[] buf = strQuery.getBytes(); /* Create UDP-packet with * data & destination(url+port) */ DatagramPacket packet = new DatagramPacket(buf, buf.length, serverAddr, Server.SERVERPORT); Log.d("UDP", "C: Sending: '" + new String(buf) + "'"); /* Send out the packet */ socket.setSoTimeout(5000); socket.send(packet); Log.d("UDP", "C: Sent."); Log.d("UDP", "C: Done."); // http://code.google.com/p/android/issues/detail?id=2917 byte[] buffer= new byte[1024*100]; DatagramPacket receivePacket = new DatagramPacket(buffer, buffer.length); //, serverAddr, Server.SERVERPORT); socket.receive(receivePacket); HelloWorldActivity.tv.setText("TTT"); String x = new String(receivePacket.getData()); Log.d("UDP", "C: Received: '" + x + "'"); HelloWorldActivity.tv.setText(x); } catch (Exception e) { HelloWorldActivity.tv.setText(e.getMessage()); Log.e("UDP", "C: Error", e); } } public class Server { /* //public static java.lang.string SERVERIP; public static String SERVERNAME = "monster.idsoftware.com"; public static String SERVERIP = "192.246.40.56"; public static int SERVERPORT = 27950; public static int PROTOCOL = 68; */ //public static String SERVERNAME="monster.idsoftware.com"; public static String SERVERNAME="dpmaster.deathmask.net"; public static String SERVERIP="192.246.40.56"; public static int SERVERPORT=27950; //public static int iProtocol= 68; // Quake3 public static int iProtocol=71; // OpenArena } Android manifest: <?xml version="1.0" encoding="utf-8"?> <use-permission id="android.permission.READ_CONTACTS" /> <use-permission android:name="android.permission.WRITE_SETTINGS" /> <uses-permission android:name="android.permission.READ_CONTACTS" /> <uses-permission android:name="android.permission.CALL_PHONE" /> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> <uses-permission android:name="android.permission.ACCESS_GPS" /> <uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" /> <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /> <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> <uses-permission android:name="android.permission.ACCESS_LOCATION" /> <uses-permission android:name="android.permission.ACCESS_ASSISTED_GPS" /> <uses-permission android:name="android.permission.ACCESS_CELL_ID" /> <uses-permission android:name="android.permission.RECEIVE_SMS" /> <uses-permission android:name="android.permission.VIBRATE" /> <uses-permission android:name="android.permission.WAKE_LOCK" /> <application android:icon="@drawable/icon" android:label="AAA New Application" > <activity android:name="HelloWorldActivity"> <intent-filter> <action android:name="android.intent.action.MAIN"/> <category android:name="android.intent.category.LAUNCHER"/> </intent-filter> </activity> </application>

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• Singleton by Jon Skeet clarification

  - by amutha

  public sealed class Singleton { Singleton() { } public static Singleton Instance { get { return Nested.instance; } } class Nested { // Explicit static constructor to tell C# compiler // not to mark type as beforefieldinit static Nested() { } internal static readonly Singleton instance = new Singleton(); } } I wish to implement Jon Skeet's Singleton pattern in my current application in C#. I have two doubts on the code 1) How is it possible to access the outer class inside nested class? I mean internal static readonly Singleton instance = new Singleton(); Is something called closure? 2) I did not get this comment // Explicit static constructor to tell C# compiler // not to mark type as beforefieldinit what does this comment suggest us?

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• threaded serial port IOException when writing

  - by John McDonald

  Hi, I'm trying to write a small application that simply reads data from a socket, extracts some information (two integers) from the data and sends the extracted information off on a serial port. The idea is that it should start and just keep going. In short, it works, but not for long. After a consistently short period I start to receive IOExceptions and socket receive buffer is swamped. The thread framework has been taken from the MSDN serial port example. The delay in send(), readThread.Join(), is an effort to delay read() in order to allow serial port interrupt processing a chance to occur, but I think I've misinterpreted the join function. I either need to sync the processes more effectively or throw some data away as it comes in off the socket, which would be fine. The integer data is controlling a pan tilt unit and I'm sure four times a second would be acceptable, but not sure on how to best acheive either, any ideas would be greatly appreciated, cheers. using System; using System.Collections.Generic; using System.Text; using System.IO.Ports; using System.Threading; using System.Net; using System.Net.Sockets; using System.IO; namespace ConsoleApplication1 { class Program { static bool _continue; static SerialPort _serialPort; static Thread readThread; static Thread sendThread; static String sendString; static Socket s; static int byteCount; static Byte[] bytesReceived; // synchronise send and receive threads static bool dataReceived; const int FIONREAD = 0x4004667F; static void Main(string[] args) { dataReceived = false; readThread = new Thread(Read); sendThread = new Thread(Send); bytesReceived = new Byte[16384]; // Create a new SerialPort object with default settings. _serialPort = new SerialPort("COM4", 38400, Parity.None, 8, StopBits.One); // Set the read/write timeouts _serialPort.WriteTimeout = 500; _serialPort.Open(); string moveMode = "CV "; _serialPort.WriteLine(moveMode); s = null; IPHostEntry hostEntry = Dns.GetHostEntry("localhost"); foreach (IPAddress address in hostEntry.AddressList) { IPEndPoint ipe = new IPEndPoint(address, 10001); Socket tempSocket = new Socket(ipe.AddressFamily, SocketType.Stream, ProtocolType.Tcp); tempSocket.Connect(ipe); if (tempSocket.Connected) { s = tempSocket; s.ReceiveBufferSize = 16384; break; } else { continue; } } readThread.Start(); sendThread.Start(); while (_continue) { Thread.Sleep(10); ;// Console.WriteLine("main..."); } readThread.Join(); _serialPort.Close(); s.Close(); } public static void Read() { while (_continue) { try { //Console.WriteLine("Read"); if (!dataReceived) { byte[] outValue = BitConverter.GetBytes(0); // Check how many bytes have been received. s.IOControl(FIONREAD, null, outValue); uint bytesAvailable = BitConverter.ToUInt32(outValue, 0); if (bytesAvailable > 0) { Console.WriteLine("Read thread..." + bytesAvailable); byteCount = s.Receive(bytesReceived); string str = Encoding.ASCII.GetString(bytesReceived); //str = Encoding::UTF8->GetString( bytesReceived ); string[] split = str.Split(new Char[] { '\t', '\r', '\n' }); string filteredX = (split.GetValue(7)).ToString(); string filteredY = (split.GetValue(8)).ToString(); string[] AzSplit = filteredX.Split(new Char[] { '.' }); filteredX = (AzSplit.GetValue(0)).ToString(); string[] ElSplit = filteredY.Split(new Char[] { '.' }); filteredY = (ElSplit.GetValue(0)).ToString(); // scale values int x = (int)(Convert.ToInt32(filteredX) * 1.9); string scaledAz = x.ToString(); int y = (int)(Convert.ToInt32(filteredY) * 1.9); string scaledEl = y.ToString(); String moveAz = "PS" + scaledAz + " "; String moveEl = "TS" + scaledEl + " "; sendString = moveAz + moveEl; dataReceived = true; } } } catch (TimeoutException) {Console.WriteLine("timeout exception");} catch (NullReferenceException) {Console.WriteLine("Read NULL reference exception");} } } public static void Send() { while (_continue) { try { if (dataReceived) { // sleep Read() thread to allow serial port interrupt processing readThread.Join(100); // send command to PTU dataReceived = false; Console.WriteLine(sendString); _serialPort.WriteLine(sendString); } } catch (TimeoutException) { Console.WriteLine("Timeout exception"); } catch (IOException) { Console.WriteLine("IOException exception"); } catch (NullReferenceException) { Console.WriteLine("Send NULL reference exception"); } } } } }

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• How can I implement an abstract singleton class in Java?

  - by Simon

  Here is my sample abstract singleton class: public abstract class A { protected static A instance; public static A getInstance() { return instance; } //...rest of my abstract methods... } And here is the concrete implementation: public class B extends A { private B() { } static { instance = new B(); } //...implementations of my abstract methods... } Unfortunately I can't get the static code in class B to execute, so the instance variable never gets set. I have tried this: Class c = B.class; A.getInstance() - returns null; and this ClassLoader.getSystemClassLoader().loadClass("B"); A.getInstance() - return null; Running both these in the eclipse debugger the static code never gets executed. The only way I could find to get the static code executed is to change the accessibility on B's constructor to public, and to call it. I'm using sun-java6-jre on Ubuntu 32bit to run these tests.

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• implement N-Tier Entity Framework 4.0 with DTOs

  - by kathy

  Hi, I'm currently building a web based system and trying to implement N-Tier Entity Framework 4.0 with DTOs in a SOA Architecture. I am having a problem understanding how I should implement the Data Access Layer (DAL) , the Business Logic Layer (BLL) and the Presentation Layer. Let’s suppose that I have a “useraccount” entity has the following : Id FirstName LastName AuditFields_InsertDate AuditFields_UpdateDate In the DAL I created a class “UserAccountsData.cs” as the following : using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace OrderSystemDAL { public static class UserAccountsData { public static int Insert(string firstName, string lastName, DateTime insertDate) { using (OrderSystemEntities db = new OrderSystemEntities()) { return Insert(db, firstName, lastName, insertDate); } } public static int Insert(OrderSystemEntities db, string firstName, string lastName, DateTime insertDate) { return db.UserAccounts_Insert(firstName, lastName, insertDate, insertDate).ElementAt(0).Value; } public static void Update(int id, string firstName, string lastName, DateTime updateDate) { using (OrderSystemEntities db = new OrderSystemEntities()) { Update(db, id, firstName, lastName, updateDate); } } public static void Update(OrderSystemEntities db, int id, string firstName, string lastName, DateTime updateDate) { db.UserAccounts_Update(id, firstName, lastName, updateDate); } public static void Delete(int id) { using (OrderSystemEntities db = new OrderSystemEntities()) { Delete(db, id); } } public static void Delete(OrderSystemEntities db, int id) { db.UserAccounts_Delete(id); } public static UserAccount SelectById(int id) { using (OrderSystemEntities db = new OrderSystemEntities()) { return SelectById(db, id); } } public static UserAccount SelectById(OrderSystemEntities db, int id) { return db.UserAccounts_SelectById(id).ElementAtOrDefault(0); } public static List<UserAccount> SelectAll() { using (OrderSystemEntities db = new OrderSystemEntities()) { return SelectAll(db); } } public static List<UserAccount> SelectAll(OrderSystemEntities db) { return db.UserAccounts_SelectAll().ToList(); } } } And in the BLL I created a class “UserAccountEO.cs” as the following : using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Collections; using OrderSystemDAL; namespace OrderSystemBLL { public class UserAccountEO { public int Id { get; set; } public string FirstName { get; set; } public string LastName { get; set; } public DateTime InsertDate { get; set; } public DateTime UpdateDate { get; set; } public string FullName { get { return LastName + ", " + FirstName; } } public bool Save(ref ArrayList validationErrors) { ValidateSave(ref validationErrors); if (validationErrors.Count == 0) { if (Id == 0) { Id = UserAccountsData.Insert(FirstName, LastName, DateTime.Now); } else { UserAccountsData.Update(Id, FirstName, LastName, DateTime.Now); } return true; } else { return false; } } private void ValidateSave(ref ArrayList validationErrors) { if (FirstName.Trim() == "") { validationErrors.Add("The First Name is required."); } if (LastName.Trim() == "") { validationErrors.Add("The Last Name is required."); } } public void Delete(ref ArrayList validationErrors) { ValidateDelete(ref validationErrors); if (validationErrors.Count == 0) { UserAccountsData.Delete(Id); } } private void ValidateDelete(ref ArrayList validationErrors) { //Check for referential integrity. } public bool Select(int id) { UserAccount userAccount = UserAccountsData.SelectById(id); if (userAccount != null) { MapData(userAccount); return true; } else { return false; } } internal void MapData(UserAccount userAccount) { Id = userAccount.Id; FirstName = userAccount.FristName; LastName = userAccount.LastName; InsertDate = userAccount.AuditFields_InsertDate; UpdateDate = userAccount.AuditFields_UpdateDate; } public static List<UserAccountEO> SelectAll() { List<UserAccountEO> userAccounts = new List<UserAccountEO>(); List<UserAccount> userAccountDTOs = UserAccountsData.SelectAll(); foreach (UserAccount userAccountDTO in userAccountDTOs) { UserAccountEO userAccountEO = new UserAccountEO(); userAccountEO.MapData(userAccountDTO); userAccounts.Add(userAccountEO); } return userAccounts; } } } And in the PL I created a webpage as the following : using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using OrderSystemBLL; using System.Collections; namespace OrderSystemUI { public partial class Users : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { LoadUserDropDownList(); } } private void LoadUserDropDownList() { ddlUsers.DataSource = UserAccountEO.SelectAll(); ddlUsers.DataTextField = "FullName"; ddlUsers.DataValueField = "Id"; ddlUsers.DataBind(); } } } Is the above way the right way to Implement the DTOs pattern in n-tier Architecture using EF4 ??? I would appreciate your help Thanks.

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• Rendering HTML in Java

  - by ferronrsmith

  I am trying to create a help panel for an application I am working on. The help file as already been created using html technology and I would like it to be rendered in a pane and shown. All the code I have seen shows how to render a site e.g. "http://google.com". I want to render a file from my pc e.g. "file://c:\tutorial.html" This is the code i have, but it doesn't seem to be working. import javax.swing.JEditorPane; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JScrollPane; import javax.swing.SwingUtilities; import java.awt.Color; import java.awt.Container; import java.io.IOException; import static java.lang.System.err; import static java.lang.System.out; final class TestHTMLRendering { // ------------------------------ CONSTANTS ------------------------------ /** * height of frame in pixels */ private static final int height = 1000; /** * width of frame in pixels */ private static final int width = 1000; private static final String RELEASE_DATE = "2007-10-04"; /** * title for frame */ private static final String TITLE_STRING = "HTML Rendering"; /** * URL of page we want to display */ private static final String URL = "file://C:\\print.html"; /** * program version */ private static final String VERSION_STRING = "1.0"; // --------------------------- main() method --------------------------- /** * Debugging harness for a JFrame * * @param args command line arguments are ignored. */ @SuppressWarnings( { "UnusedParameters" } ) public static void main( String args[] ) { // Invoke the run method on the Swing event dispatch thread // Sun now recommends you call ALL your GUI methods on the Swing // event thread, even the initial setup. // Could also use invokeAndWait and catch exceptions SwingUtilities.invokeLater( new Runnable() { /** * } fire up a JFrame on the Swing thread */ public void run() { out.println( "Starting" ); final JFrame jframe = new JFrame( TITLE_STRING + " " + VERSION_STRING ); Container contentPane = jframe.getContentPane(); jframe.setSize( width, height ); contentPane.setBackground( Color.YELLOW ); contentPane.setForeground( Color.BLUE ); jframe.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); try { out.println( "acquiring URL" ); JEditorPane jep = new JEditorPane( URL ); out.println( "URL acquired" ); JScrollPane jsp = new JScrollPane( jep, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED ); contentPane.add( jsp ); } catch ( IOException e ) { err.println( "can't find URL" ); contentPane.add( new JLabel( "can't find URL" ) ); } jframe.validate(); jframe.setVisible( true ); // Shows page, with HTML comments erroneously displayed. // The links are not clickable. } } ); }// end main }// end TestHTMLRendering

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• GORM ID generation and belongsTo association ?

  - by fabien-barbier

  I have two domains : class CodeSetDetail { String id String codeSummaryId static hasMany = [codes:CodeSummary] static constraints = { id(unique:true,blank:false) } static mapping = { version false id column:'code_set_detail_id', generator: 'assigned' } } and : class CodeSummary { String id String codeClass String name String accession static belongsTo = [codeSetDetail:CodeSetDetail] static constraints = { id(unique:true,blank:false) } static mapping = { version false id column:'code_summary_id', generator: 'assigned' } } I get two tables with columns: code_set_detail: code_set_detail_id code_summary_id and code_summary: code_summary_id code_set_detail_id (should not exist) code_class name accession I would like to link code_set_detail table and code_summary table by 'code_summary_id' (and not by 'code_set_detail_id'). Note : 'code_summary_id' is define as column in code_set_detail table, and define as primary key in code_summary table. To sum-up, I would like define 'code_summary_id' as primary key in code_summary table, and map 'code_summary_id' in code_set_detail table. How to define a primary key in a table, and also map this key to another table ?

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• Python's equivalence?

  - by user304014

  Is there anyway to transform the following code in Java to Python's equivalence? public class Animal{ public enum AnimalBreed{ Dog, Cat, Cow, Chicken, Elephant } private static final int Animals = AnimalBreed.Dog.ordinal(); private static final String[] myAnimal = new String[Animals]; private static Animal[] animal = new Animal[Animals]; public static final Animal DogAnimal = new Animal(AnimalBreed.Dog, "woff"); public static final Animal CatAnimal = new Animal(AnimalBreed.Cat, "meow"); private AnimalBreed breed; public static Animal myDog (String name) { return new Animal(AnimalBreed.Dog, name); } }

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• Breaking through the class sealing

  - by Jason Crease

  Do you understand 'sealing' in C#?  Somewhat?  Anyway, here's the lowdown. I've done this article from a C# perspective, but I've occasionally referenced .NET when appropriate. What is sealing a class? By sealing a class in C#, you ensure that you ensure that no class can be derived from that class.  You do this by simply adding the word 'sealed' to a class definition: public sealed class Dog {} Now writing something like " public sealed class Hamster: Dog {} " you'll get a compile error like this: 'Hamster: cannot derive from sealed type 'Dog' If you look in an IL disassembler, you'll see a definition like this: .class public auto ansi sealed beforefieldinit Dog extends [mscorlib]System.Object Note the addition of the word 'sealed'. What about sealing methods? You can also seal overriding methods.  By adding the word 'sealed', you ensure that the method cannot be overridden in a derived class.  Consider the following code: public class Dog : Mammal { public sealed override void Go() { } } public class Mammal { public virtual void Go() { } } In this code, the method 'Go' in Dog is sealed.  It cannot be overridden in a subclass.  Writing this would cause a compile error: public class Dachshund : Dog { public override void Go() { } } However, we can 'new' a method with the same name.  This is essentially a new method; distinct from the 'Go' in the subclass: public class Terrier : Dog { public new void Go() { } } Sealing properties? You can also seal seal properties.  You add 'sealed' to the property definition, like so: public sealed override string Name {     get { return m_Name; }     set { m_Name = value; } } In C#, you can only seal a property, not the underlying setters/getters.  This is because C# offers no override syntax for setters or getters.  However, in underlying IL you seal the setter and getter methods individually - a property is just metadata. Why bother sealing? There are a few traditional reasons to seal: Invariance. Other people may want to derive from your class, even though your implementation may make successful derivation near-impossible.  There may be twisted, hacky logic that could never be second-guessed by another developer.  By sealing your class, you're protecting them from wasting their time.  The CLR team has sealed most of the framework classes, and I assume they did this for this reason. Security.  By deriving from your type, an attacker may gain access to functionality that enables him to hack your system.  I consider this a very weak security precaution. Speed.  If a class is sealed, then .NET doesn't need to consult the virtual-function-call table to find the actual type, since it knows that no derived type can exist.  Therefore, it could emit a 'call' instead of 'callvirt' or at least optimise the machine code, thus producing a performance benefit.  But I've done trials, and have been unable to demonstrate this If you have an example, please share! All in all, I'm not convinced that sealing is interesting or important.  Anyway, moving-on... What is automatically sealed? Value types and structs.  If they were not always sealed, all sorts of things would go wrong.  For instance, structs are laid-out inline within a class.  But what if you assigned a substruct to a struct field of that class?  There may be too many fields to fit. Static classes.  Static classes exist in C# but not .NET.  The C# compiler compiles a static class into an 'abstract sealed' class.  So static classes are already sealed in C#. Enumerations.  The CLR does not track the types of enumerations - it treats them as simple value types.  Hence, polymorphism would not work. What cannot be sealed? Interfaces.  Interfaces exist to be implemented, so sealing to prevent implementation is dumb.  But what if you could prevent interfaces from being extended (i.e. ban declarations like "public interface IMyInterface : ISealedInterface")?  There is no good reason to seal an interface like this.  Sealing finalizes behaviour, but interfaces have no intrinsic behaviour to finalize Abstract classes.  In IL you can create an abstract sealed class.  But C# syntax for this already exists - declaring a class as a 'static', so it forces you to declare it as such. Non-override methods.  If a method isn't declared as override it cannot be overridden, so sealing would make no difference.  Note this is stated from a C# perspective - the words are opposite in IL.  In IL, you have four choices in total: no declaration (which actually seals the method), 'virtual' (called 'override' in C#), 'sealed virtual' ('sealed override' in C#) and 'newslot virtual' ('new virtual' or 'virtual' in C#, depending on whether the method already exists in a base class). Methods that implement interface methods.  Methods that implement an interface method must be virtual, so cannot be sealed. Fields.  A field cannot be overridden, only hidden (using the 'new' keyword in C#), so sealing would make no sense.

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• Managing of shared resources between classes?

  - by Axarydax

  Imagine that I have a several Viewer component that are used for displaying text and they have few modes that user can switch (different font presets for viewing text/binary/hex). What would be the best approach for managing shared objects - for example fonts, find dialog, etc? I figured that static class with lazily initialized objects would be OK, but this might be the wrong idea. static class ViewerStatic { private static Font monospaceFont; public static Font MonospaceFont { get { if (monospaceFont == null) //TODO read font settings from configuration monospaceFont = new Font(FontFamily.GenericMonospace, 9, FontStyle.Bold); return monospaceFont; } } private static Font sansFont; public static Font SansFont { get { if (sansFont == null) //TODO read font settings from configuration sansFont = new Font(FontFamily.GenericSansSerif, 9, FontStyle.Bold); return sansFont; } } }

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