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  • Is there a standard mapping between JSON and Protocol Buffers?

    - by Daniel Earwicker
    From a comment on the announcement blog post: Regarding JSON: JSON is structured similarly to Protocol Buffers, but protocol buffer binary format is still smaller and faster to encode. JSON makes a great text encoding for protocol buffers, though -- it's trivial to write an encoder/decoder that converts arbitrary protocol messages to and from JSON, using protobuf reflection. This is a good way to communicate with AJAX apps, since making the user download a full protobuf decoder when they visit your page might be too much. It may be trivial to cook up a mapping, but is there a single "obvious" mapping between the two that any two separate dev teams would naturally settle on? If two products supported PB data and could interoperate because they shared the same .proto spec, I wonder if they would still be able to interoperate if they independently introduced a JSON reflection of the same spec. There might be some arbitrary decisions to be made, e.g. should enum values be represented by a string (to be human-readable a la typical JSON) or by their integer value? So is there an established mapping, and any open source implementations for generating JSON encoder/decoders from .proto specs?

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  • Loading and binding a serialized view model to a WPF window?

    - by generalt
    Hello all. I'm writing a one-window UI for a simple ETL tool. The UI consists of the window, the code behind for the window, a view model for the window, and the business logic. I wanted to provide functionality to the users to save the state of the UI because the content of about 10-12 text boxes will be reused between sessions, but are specific to the user. I figured I could serialize the view model, which contains all the data from the textboxes, and this works fine, but I'm having trouble loading the information in the serialized XML file back into the text boxes. Constructor of window: public ETLWindow() { InitializeComponent(); _viewModel = new ViewModel(); this.DataContext = _viewModel; _viewModel.State = Constants.STATE_IDLE; Loaded += new RoutedEventHandler(MainWindow_Loaded); } XAML: <TextBox x:Name="targetDirectory" IsReadOnly="true" Text="{Binding TargetDatabaseDirectory, UpdateSourceTrigger=PropertyChanged}"/> ViewModel corresponding property: private string _targetDatabaseDirectory; [XmlElement()] public string TargetDatabaseDirectory { get { return _targetDatabaseDirectory; } set { _targetDatabaseDirectory = value; OnPropertyChanged(DataUtilities.General.Utilities.GetPropertyName(() => new ViewModel().TargetDatabaseDirectory)); } Load event in code behind: private void loadState_Click(object sender, RoutedEventArgs e) { string statePath = this.getFilePath(); _viewModel = ViewModel.LoadModel(statePath); } As you can guess, the LoadModel method deserializes the serialized file on the user's drive. I couldn't find much on the web regarding this issue. I know this probably has something to do with my bindings. Is there some way to refresh on the bindings on the XAML after I deserialize the view model? Or perhaps refresh all properties on the view model? Or am I completely insane thinking any of this could be done? Thanks.

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  • Ldap query returns null result when deployed.

    - by Trey Carroll
    I'm using a very simple Ldap query in my asp.net mvc 2.0 site: String ldapPath = ConfigReader.LdapPath; String emailAddress = null; try { DirectorySearcher search = new DirectorySearcher(ConfigReader.LdapPath); search.Filter = String.Format("(&(objectClass=user)(objectCategory=person)(objectSid={0})) ", securityIdentifierValue); // add the mail property to the list of props to retrieve search.PropertiesToLoad.Add("mail"); var result = search.FindOne(); if (result == null) { throw new Exception("Ldap Query with filter:" + search.Filter.ToString() + " returned a null value (no match found)"); } else { emailAddress = result.Properties["mail"][0].ToString(); } } catch (ArgumentOutOfRangeException aoorEx) { throw new Exception( "The query could not find an email for this user."); } catch (Exception ex) { //_log.Error(string.Format("======!!!!!! ERROR ERROR ERROR !!!!! in LdapLookupUtil.cs getEmailFromLdap Exception: {0}", ex)); throw ex; } return emailAddress; It works fine on my localhost machine. It works fine when I run it in VS2010 on the server. It always returns a null result when deployed. Here is my web.config: Asp.Net Configuration option in Visual Studio. A full list of settings and comments can be found in machine.config.comments usually located in \Windows\Microsoft.Net\Framework\v2.x\Config -- section enables configuration of the security authentication mode used by ASP.NET to identify an incoming user. -- <!-- -- section enables configuration of what to do if/when an unhandled error occurs during the execution of a request. Specifically, it enables developers to configure html error pages to be displayed in place of a error stack trace. -- I'm running it under the default app pool. Does anybody see the problem? This is driving me crazy!

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  • Trying to return data asynchronously using jQuery AND jSon in MVC 2.0

    - by Calibre2010
    Hi, I am trying to use Jquerys getJSON method to return data server side to my browser, what happens is the url the getJSON method points to does get reached but upon the postback the result does not get returned to the browser for some odd reason. I wasen't sure if it was because I was using MVC 2.0 and jQuery 1.4.1 and it differs to the MVC 1.0 version and jQuerys 1.3.2 version. . this is the code sections Controller public JsonResult StringReturn() { NameDTO myName = new NameDTO(); myName.nameID = 1; myName.name= "James"; myName.nameDescription = "Jmaes"; return Json(myName); } View with JQuery <script type="text/javascript"> $(document).ready(function () { $("#myButton").click(function () { $.getJSON("Home/StringReturn/", null, function (data) { alert(data.name); $("#show").append($("<div>" + data.name + "</div>")); }); }); }); </script> HTML <input type="button" value="clickMe" id="myButton"/> <div id="show">d</div>

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  • Converting python collaborative filtering code to use Map Reduce

    - by Neil Kodner
    Using Python, I'm computing cosine similarity across items. given event data that represents a purchase (user,item), I have a list of all items 'bought' by my users. Given this input data (user,item) X,1 X,2 Y,1 Y,2 Z,2 Z,3 I build a python dictionary {1: ['X','Y'], 2 : ['X','Y','Z'], 3 : ['Z']} From that dictionary, I generate a bought/not bought matrix, also another dictionary(bnb). {1 : [1,1,0], 2 : [1,1,1], 3 : [0,0,1]} From there, I'm computing similarity between (1,2) by calculating cosine between (1,1,0) and (1,1,1), yielding 0.816496 I'm doing this by: items=[1,2,3] for item in items: for sub in items: if sub >= item: #as to not calculate similarity on the inverse sim = coSim( bnb[item], bnb[sub] ) I think the brute force approach is killing me and it only runs slower as the data gets larger. Using my trusty laptop, this calculation runs for hours when dealing with 8500 users and 3500 items. I'm trying to compute similarity for all items in my dict and it's taking longer than I'd like it to. I think this is a good candidate for MapReduce but I'm having trouble 'thinking' in terms of key/value pairs. Alternatively, is the issue with my approach and not necessarily a candidate for Map Reduce?

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  • Declaring functors for comparison ??

    - by Mr.Gando
    Hello, I have seen other people questions but found none that applied to what I'm trying to achieve here. I'm trying to sort Entities via my EntityManager class using std::sort and a std::vector<Entity *> /*Entity.h*/ class Entity { public: float x,y; }; struct compareByX{ bool operator()(const GameEntity &a, const GameEntity &b) { return (a.x < b.x); } }; /*Class EntityManager that uses Entitiy*/ typedef std::vector<Entity *> ENTITY_VECTOR; //Entity reference vector class EntityManager: public Entity { private: ENTITY_VECTOR managedEntities; public: void sortEntitiesX(); }; void EntityManager::sortEntitiesX() { /*perform sorting of the entitiesList by their X value*/ compareByX comparer; std::sort(entityList.begin(), entityList.end(), comparer); } I'm getting a dozen of errors like : error: no match for call to '(compareByX) (GameEntity* const&, GameEntity* const&)' : note: candidates are: bool compareByX::operator()(const GameEntity&, const GameEntity&) I'm not sure but ENTITY_VECTOR is std::vector<Entity *> , and I don't know if that could be the problem when using the compareByX functor ? I'm pretty new to C++, so any kind of help is welcome.

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  • A function where small changes in input always result in large changes in output

    - by snowlord
    I would like an algorithm for a function that takes n integers and returns one integer. For small changes in the input, the resulting integer should vary greatly. Even though I've taken a number of courses in math, I have not used that knowledge very much and now I need some help... An important property of this function should be that if it is used with coordinate pairs as input and the result is plotted (as a grayscale value for example) on an image, any repeating patterns should only be visible if the image is very big. I have experimented with various algorithms for pseudo-random numbers with little success and finally it struck me that md5 almost meets my criteria, except that it is not for numbers (at least not from what I know). That resulted in something like this Python prototype (for n = 2, it could easily be changed to take a list of integers of course): import hashlib def uniqnum(x, y): return int(hashlib.md5(str(x) + ',' + str(y)).hexdigest()[-6:], 16) But obviously it feels wrong to go over strings when both input and output are integers. What would be a good replacement for this implementation (in pseudo-code, python, or whatever language)?

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  • Understanding evaluation of expressions containing '++' and '->' operators in C.

    - by Leif Ericson
    Consider this example: struct { int num; } s, *ps; s.num = 0; ps = &s; ++ps->num; printf("%d", s.num); /* Prints 1 */ It prints 1. So I understand that it is because according to operators precedence, -> is higher than ++, so the value ps->num (which is 0) is firstly fetched and then the ++ operator operates on it, so it increments it to 1. struct { int num; } s, *ps; s.num = 0; ps = &s; ps++->num; printf("%d", s.num); /* Prints 0 */ In this example I get 0 and I don't understand why; the explanation of the first example should be the same for this example. But it seems that this expression is evaluated as follows: At first, the operator ++ operates, and it operates on ps, so it increments it to the next struct. Only then -> operates and it does nothing because it just fetches the num field of the next struct and does nothing with it. But it contradicts the precedence of operators, which says that -> have higher precedence than ++. Can someone explain this behavior? Edit: After reading two answers which refer to a C++ precedence tables which indicate that a prefix ++/-- operators have lower precedence than ->, I did some googling and came up with this link that states that this rule applies also to C itself. It fits exactly and fully explains this behavior, but I must add that the table in this link contradicts a table in my own copy of K&R ANSI C. So if you have suggestions as to which source is correct I would like to know. Thanks.

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  • CIE XYZ colorspace: is it RGBA or XYZA?

    - by Tronic
    I plan to write a painting program based on linear combinations of xy plane points (0,1), (1,0 ) and (0,0). Such system works identically to RGB, except that the primaries are not within the gamut but at the corners of a triangle that encloses the entire gamut, therefore allowing for all colors to be reproduced. I have seen the three points being referred to as X, Y and Z (upper case) somewhere, but I cannot find the page anymore. My pixel format stores the intensity of each of those three components the same way as RGB does, together with alpha value. This allows using pretty much any image manipulation operation designed for RGBA without modifying the code. What is my format called? Is it XYZA, RGBA or something else? Google doesn't seem to know of XYZA and RGBA will get confused with sRGB + alpha (which I also need to use in the same program). Notice that the primaries X, Y and Z and their intensities have little to do with the x, y and z coordinates (lower case) that are more commonly used.

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  • How to access a method on a generic datacontext which is only created at runtime

    - by Jeremy Holt
    I'm creating my generic DataContext using only the connectionString in the ctor. I have no issues in retrieving the table using DataContext.GetTable(). However, I need to also be able to retrieve entities of inline table functions. The dbml designer generates public IQueryable<testFunctionResult> testFunction() { return this.CreateMethodCallQuery<testFunctionResult>(this, ((MethodInfo)(MethodInfo.GetCurrentMethod()))); } The question is how do I get the MethodInfo.GetCurrentMethod() when the DataContext has no method called "testFunction", i.e.typeof(DataContext).GetMethod("testFunction") returns null? What I'm trying to achieve is something like: public class UnitofWork<T> { public UnitofWork(string connectionString) { this.DataContext = new DataContext(connectionString); } public UnitofWork(IQueryable<T> tableEntity) { _tableEntity = tableEntity; } public IQueryable<T> TableEntity { get { if (DataContext == null) return _tableEntity; var metaType = DataContext.Mapping.GetMetaType(typeof (T)); if (metaType.IsEntity) _tableEntity = DataContext.GetTable<T>(); else { var s = typeof(T).Name; string methodName = s.Substring(0, s.IndexOf("Result")) + "()"; // the designer automatically affixes "Result" to the type name // Make a method from methodName // _tableEntity = DataContext.CreateMethodCallQuery(DataContext, method, new object[]{}); } return _tableEntity; } set { _tableEntity = value; } } ) Thanks in advance for any insight Jeremy

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  • How to get "AuthSub " token in C#? For google APPS Contacts ?

    - by Pari
    Hi, I fount this code on net : HttpWebRequest update = (HttpWebRequest)WebRequest.Create(**editUrl** ); // editUrl is a string containing the contact's edit URL update.Method = "PUT"; update.ContentType = "application/atom+xml"; update.Headers.Add(HttpRequestHeader.Authorization, "GoogleLogin auth=" + **AuthToken**); update.Headers.Add(HttpRequestHeader.IfMatch, **etag**); // etag is a string containing the <entry> element's gd:etag attribute value update.Headers.Add("GData-Version", "3.0"); Stream streamRequest = update.GetRequestStream(); StreamWriter streamWriter = new StreamWriter(streamRequest, Encoding.UTF8); streamWriter.Write(entry); // entry is the string representation of the atom entry to update streamWriter.Close(); WebResponse response = update.GetResponse(); But here i am not getting what to put in " editurl" , "AuthToken" and "Etag". a) I studied abt "AuthToken" from this Link .But not getting how to create it? Can anyone help me out here? b) Also not getting " editurl" and "Etag". I am trying to use this method to Migrate my contacts to Google Apps. Thanx

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  • Checking if an array contains all elements of another array

    - by mozcelikors
    I'm designing an electrical engineering application. However, i'm stuck on this: I have the following array <?php // Static Array $GroupOfEight = array ( array(0,1,3,2,4,5,7,6), array(4,5,6,7,16,12,13,14), array(12,13,15,14,8,9,11,10), array(2,6,14,10,3,7,15,11), array(1,3,5,7,13,15,9,11), array(0,4,12,8,1,5,13,9), array(0,1,3,2,8,9,11,10) ); ?> And I have another array, but this one is one dimensional. <?php $myStack = array(0,1,3,2,4,5,7,6); //Dynamic, gets value by POST method. ?> What I want to do is to check if $myStack is equal to any sub array of $GroupOfEight array. ( Number ordering is not important. The script should just check if every elements contained. It's not important if their order is same or not. ) Here is what I've done to solve the issue so far: <?php //Check if stackArray contains 8group for($i=0; $i<count($GroupOfEight);$i++) for($j=0; $j<count($GroupOfEight[$i]); $j++){ //$containsSearch = count(array_intersect($search_this,$all)) == count($search_this); $containsSearch = count(array_intersect($stackArray,$GroupOfEight[$j])) == count($stackArray); echo $containsSearch; } ?> Please help me correct my code or introduce me the solution of this issue, Thanks.

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  • Multiple Configuration Sources for Enterprise Library 4.1?

    - by Martijn B
    Hi All, We use the caching and logging application blocks from entlib 4.1. We want to keep the configuration of those two in seperate files. How can we achieve this? It looks like entlib is always using the selectedSource as it configuration. I tried the following: <?xml version="1.0" encoding="utf-8" ?> <configuration> <configSections> <section name="enterpriseLibrary.ConfigurationSource" type="Microsoft.Practices.EnterpriseLibrary.Common.Configuration.ConfigurationSourceSection, Microsoft.Practices.EnterpriseLibrary.Common, Version=4.1.0.0, Culture=neutral, PublicKeyToken=9057346a2b2dcfc8" /> </configSections> <enterpriseLibrary.ConfigurationSource selectedSource="messagesCache"> <sources> <add name="messagesCache" filePath="Configuration\\messagesCache.config" type="Microsoft.Practices.EnterpriseLibrary.Common.Configuration.FileConfigurationSource, Microsoft.Practices.EnterpriseLibrary.Common, Version=4.1.0.0, Culture=neutral, PublicKeyToken=9057346a2b2dcfc8" /> <add name="logging" filePath="Configuration\\logging.config" type="Microsoft.Practices.EnterpriseLibrary.Common.Configuration.FileConfigurationSource, Microsoft.Practices.EnterpriseLibrary.Common, Version=4.1.0.0, Culture=neutral, PublicKeyToken=9057346a2b2dcfc8" /> </sources> </enterpriseLibrary.ConfigurationSource> </configuration> But this doesn't work because the application blocks always use the selectedSource attribute value. Any suggestions woulde be welcome! Gr Martijn

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  • How to create a column containing a string of stars to inidcate levels of a factor in a data frame i

    - by PaulHurleyuk
    (second question today - must be a bad day) I have a dataframe with various columns, inculding a concentration column (numeric), a flag highlighting invalid results (boolean) and a description of the problem (character) dput(df) structure(list(x = c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10), rawconc = c(77.4, 52.6, 86.5, 44.5, 167, 16.2, 59.3, 123, 1.95, 181), reason = structure(c(NA, NA, 2L, NA, NA, NA, 2L, 1L, NA, NA), .Label = c("Fails Acceptance Criteria", "Poor Injection"), class = "factor"), flag = c("False", "False", "True", "False", "False", "False", "True", "True", "False", "False" )), .Names = c("x", "rawconc", "reason", "flag"), row.names = c(NA, -10L), class = "data.frame") I can create a column with the numeric level of the reason column df$level<-as.numeric(df$reason) df x rawconc reason flag level 1 1 77.40 <NA> False NA 2 2 52.60 <NA> False NA 3 3 86.50 Poor Injection True 2 4 4 44.50 <NA> False NA 5 5 167.00 <NA> False NA 6 6 16.20 <NA> False NA 7 7 59.30 Poor Injection True 2 8 8 123.00 Fails Acceptance Criteria True 1 9 9 1.95 <NA> False NA 10 10 181.00 <NA> False NA and here's what I want to do to create a column with 'level' many stars, but it fails df$stars<-paste(rep("*",df$level)sep="",collapse="") Error: unexpected symbol in "df$stars<-paste(rep("*",df$level)sep" df$stars<-paste(rep("*",df$level),sep="",collapse="") Error in rep("*", df$level) : invalid 'times' argument rep("*",df$level) Error in rep("*", df$level) : invalid 'times' argument df$stars<-paste(rep("*",pmax(df$level,0,na.rm=TRUE)),sep="",collapse="") Error in rep("*", pmax(df$level, 0, na.rm = TRUE)) : invalid 'times' argument It seems that rep needs to be fed one value at a time. I feel that this should be possible (and my gut says 'use lapply' but my apply fu is v. poor) ANy one want to try ?

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  • NSUserDefaults not saving properly

    - by BWC
    Hey Guys I'm having issues with NSUserDefaults and I don't quite understand what's going on My App has 5 levels and each level does the exact same thing with NSUserDefaults (Retrieves the levels defaults, changes the value as the user plays the level and then sets the defaults and syncronizes at the end of the level) the first 4 levels...work without a hitch but the last level doesn't save the values. The app doesn't crash and the last level isn't the very last thing that happens, And I even have the defaults synchronized when the application terminates. Is there a max size on the NSUserDefaults or is there anything anyone can think of that I haven't, I'll post the code below but like I said the first four levels work perfectly //header NSUserDefaults *userData; @property(nonatomic,retain) NSUserDefaults *userData; //class file //Sets the boolean variables for the class to use userData = [NSUserDefaults standardUserDefaults]; boolOne = [userData boolForKey:@"LevelFiveBoolOne"]; boolTwo = [userData boolForKey:@"LevelFiveBoolTwo"]; boolThree = [userData boolForKey:@"LevelFiveBoolThree"]; boolFour = [userData boolForKey:@"LevelFiveBoolFour"]; boolFive = [userData boolForKey:@"LevelFiveBoolFive"]; boolSix = [userData boolForKey:@"LevelFiveBoolSix"]; boolSeven = [userData boolForKey:@"LevelFiveBoolSeven"]; //End Of Level [userData setBool:boolOne forKey:@"LevelFiveBoolOne"]; [userData setBool:boolTwo forKey:@"LevelFiveBoolTwo"]; [userData setBool:boolThree forKey:@"LevelFiveBoolThree"]; [userData setBool:boolFour forKey:@"LevelFiveBoolFour"]; [userData setBool:boolFive forKey:@"LevelFiveBoolFive"]; [userData setBool:boolSix forKey:@"LevelFiveBoolSix"]; [userData setBool:boolSeven forKey:@"LevelFiveBoolSeven"]; [userData synchronize]; When when I switch to the view that uses these defaults they values are correct but when I terminate the application and restart it, these values aren't saved, every other level does the exact same process this is the only level that doesn't work. I've stared at this for quite awhile and I'm hoping someone out there has run into the same problem and can give me some insight on how they resolved it. Thank you in Advance BWC

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  • NullReferenceException when initializing NServiceBus within web application Application_Start method

    - by SteveBering
    I am running the 2.0 RTM of NServiceBus and am getting a NullReferenceException when my MessageModule binds the CurrentSessionContext to my NHibernate sessionfactory. From within my Application_Start, I call the following method: public static void WithWeb(IUnityContainer container) { log4net.Config.XmlConfigurator.Configure(); var childContainer = container.CreateChildContainer(); childContainer.RegisterInstance<ISessionFactory>(NHibernateSession.SessionFactory); var bus = NServiceBus.Configure.WithWeb() .UnityBuilder(childContainer) .Log4Net() .XmlSerializer() .MsmqTransport() .IsTransactional(true) .PurgeOnStartup(false) .UnicastBus() .ImpersonateSender(false) .LoadMessageHandlers() .CreateBus(); var activeBus = bus.Start(); container.RegisterInstance(typeof(IBus), activeBus); } When the bus is started, my message module starts with the following: public void HandleBeginMessage() { try { CurrentSessionContext.Bind(_sessionFactory.OpenSession()); } catch (Exception e) { _log.Error("Error occurred in HandleBeginMessage of NHibernateMessageModule", e); throw; } } In looking at my log, we are logging the following error when the bind method is called: System.NullReferenceException: Object reference not set to an instance of an object. at NHibernate.Context.WebSessionContext.GetMap() at NHibernate.Context.MapBasedSessionContext.set_Session(ISession value) at NHibernate.Context.CurrentSessionContext.Bind(ISession session) Apparently, there is some issue in getting access to the HttpContext. Should this call to configure NServiceBus occur later in the lifecycle than Application_Start? Or is there another workaround that others have used to get handlers working within an Asp.NET Web application? Thanks, Steve

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  • How to Debug an exception: Type is not marked as serializable... when the type is marked as serializ

    - by rism
    I'm trying to: ((Request.Params["crmid"] != null)) in a web page. But it keeps throwing a serialzation exception: Type 'QC.Security.SL.SiteUser' in assembly 'QC.Security, Version=1.0.0.1, Culture=neutral, PublicKeyToken=null' is not marked as serializable. The type is however marked as serializable as follows: [Serializable()] public class SiteUser : IIdentity { private long _userId; public long UserId { get { return _userId; } set { _userId = value; } } private string _name; public string Name { get { return _name; } } private bool _isAuthenticated; public bool IsAuthenticated { get { return _isAuthenticated; } } private string _authenticationType; public string AuthenticationType { get { return _authenticationType; } } I've no idea how to debug this as I cant step into the serializer code to find out why its falling over. The call stack is only one frame deep before it hits [External Code]. And the error message is next to useless given that type is clearly marked as serializable. It was working fine. But now "all of a sudden" it doesn't which typically means some dumb bug in Visual Studio but rebooting doesn't help "this" time. So now I dont know if it's a stupid VS bug or a completely unrelated error for which Im getting a serialization exception or something I'm doing wrong. The truth is I just dont trust VS anymore given the number of wild goose chases Ive been on over the last several months which were "fixed" by rebooting VS 2008 or some other rediculous workaround.

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  • Managing lots of callback recursion in Nodejs

    - by Maciek
    In Nodejs, there are virtually no blocking I/O operations. This means that almost all nodejs IO code involves many callbacks. This applies to reading and writing to/from databases, files, processes, etc. A typical example of this is the following: var useFile = function(filename,callback){ posix.stat(filename).addCallback(function (stats) { posix.open(filename, process.O_RDONLY, 0666).addCallback(function (fd) { posix.read(fd, stats.size, 0).addCallback(function(contents){ callback(contents); }); }); }); }; ... useFile("test.data",function(data){ // use data.. }); I am anticipating writing code that will make many IO operations, so I expect to be writing many callbacks. I'm quite comfortable with using callbacks, but I'm worried about all the recursion. Am I in danger of running into too much recursion and blowing through a stack somewhere? If I make thousands of individual writes to my key-value store with thousands of callbacks, will my program eventually crash? Am I misunderstanding or underestimating the impact? If not, is there a way to get around this while still using Nodejs' callback coding style?

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  • Using multiple aggregate functions in an (ANSI) SQL statement

    - by morpheous
    I have aggregate functions foo(), foobar(), fredstats(), barneystats() I want to create a domain specific query language (DSQL) above my DB, to facilitate using a domain language to query the DB. The 'language' comprises of algebraic expressions (or more specifically SQL like criteria) which I use to generate (ANSI) SQL statements which are sent to the db engine. The following lines are examples of what the language statements will look like, and hopefully, it will help further clarify the concept: **Example 1** DQL statement: foobar('yellow') between 1 and 3 and fredstats('weight') > 42 Translation: fetch all rows in an underlying table where computed values for aggregate function foobar() is between 1 and 3 AND computed value for AGG FUNC fredstats() is greater than 42 **Example 2** DQL statement: fredstats('weight') < barneystats('weight') AND foo('fighter') in (9,10,11) AND foobar('green') <> 42 Translation: Fetch all rows where the specified criteria matches **Example 3** DQL statement: foobar('green') / foobar('red') <> 42 Translation: Fetch all rows where the specified criteria matches **Example 4** DQL statement: foobar('green') - foobar('red') >= 42 Translation: Fetch all rows where the specified criteria matches Given the following information: The table upon which the queries above are being executed is called 'tbl' table 'tbl' has the following structure (id int, name varchar(32), weight float) The result set returns only the tbl.id, tbl.name and the names of the aggregate functions as columns in the result set - so for example the foobar() AGG FUNC column will be called foobar in the result set. So for example, the first DQL query will return a result set with the following columns: id, name, foobar, fredstats Given the above, my questions then are: What would be the underlying SQL required for Example1 ? What would be the underlying SQL required for Example3 ? Given an algebraic equation comprising of AGGREGATE functions, Is there a way of generalizing the algorithm needed to generate the required ANSI SQL statement(s)? I am using PostgreSQL as the db, but I would prefer to use ANSI SQL wherever possible.

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  • TextBox should display text in hexadecimal in a specific format

    - by Owais Wani
    I have a textbox in my xaml file which is editable. Now according to my project requirements content in textbox should only be 0-9 and a-f (hexadecimal values) and textbox should take the input based on hexadecimal values. Demonstratation: 12 ab 32 a5 64 Now if my cursor is at the end and i go on pressing backspace, it shud remove the values as it happens in a general text box. Now If my cursor is at the beginning of a5, and i press "delete key", the value should become like: 12 ab 32 56 4 If my cursor is at the end of a5 and i press the 'delete key" nothing should happen. I had done this successful in my C++ application as follows: void CMSP430CommPanel::textEditorTextChanged (TextEditor& editor) { if(&editor == m_texti2cWrite) { int count = 0; int location; String text1 = m_texti2cWrite->getText(); String text = m_texti2cWrite->getText().removeCharacters(" "); String hexString = String::empty; int countCaret = m_texti2cWrite->getCaretPosition(); for(int i=0; i < text.length(); i++) { hexString = hexString + String (&text[i], 1); if((i+1) % 2 == 0) { if(i != text.length()-1) { hexString = hexString + T(" "); count ++; } } count ++; } m_texti2cWrite->setText(hexString,false); if(text1.length() == m_texti2cWrite->getCaretPosition()) { m_texti2cWrite->setCaretPosition(count); } else { m_texti2cWrite->setCaretPosition(countCaret); } } } where m_texti2cWrite is the name given to textbox. How can i implement the same case in my wpf application which is MVVM based. I have a textbox which shud take inputs as I said above. please help!!!

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  • How to check name of Domino Server to which lotus notes is configured? using C#

    - by Preeti
    Hi, I am trying to login Domino server. For that i am taking Lotus Notes Password and Domino Server Name from user. if (notesPassword == "" && serverName == "") { MessageBox.Show("Please enter the server name !! "); return; } else { if (connectToDomino(notesPassword, serverName)) { MessageBox.Show("Connection Established Succesfully!!.."); } else { MessageBox.Show("Connection Fail.Please Login Again To Begin"); } }//else and in public bool connectToDomino(string NotesPassword, string strDominoServerName) { try { if (_lotesNotesSession == null) { NotesSession notesSession = new Domino.NotesSessionClass(); notesSession.Initialize(NotesPassword); } return true; } catch(Exception ex) { return false; } } Here i am initializing notes password.So in this case it is just verifying Notes Password. So even if user enters invalid entry of server name above function will return true. I tried : string serverName = notesSession.ServerName; But it is showing null value. :( Regards, Preeti

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  • IIS7 GrantByDefault

    - by jonot
    I have an application (written in c#) that allow me to set IIS to allow or deny access to a website from all ip addresses. The application works fine for IIS6 however it does not work with IIS 7 (even with IIS 6 WMI Compatibility installed). heres the code (basically) Type typ = this.Entry.Properties[IIsWebDirectoryProperty.IPSecurity][0].GetType(); var securityProp = this.Entry.Properties[IIsWebDirectoryProperty.IPSecurity][0]; typ.InvokeMember("GrantByDefault", BindingFlags.DeclaredOnly | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.SetProperty, null, securityProp, new object[] { IPSecurity.GrantByDefault }); this.Entry.CommitChanges(); I have checked the metabase for both IIS6 and IIS7 using the metabase explorer and the only diffecnce I can see is that the "IPSecurity" property does not appear in IIS7 until you also add a an allow or deny IP address, through IIS Manager. Whats really got me stumped is that even when I edit the feature setting to Deny access in the IIS Manager there is no change to the metabase or to the web.config in the site root! So how/where is this property being set and read from? And how can I set and read value of this property programmatically?

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  • Validating User Input? C#

    - by Alex
    Hi, in an assignment, I have designed a input validation loop in C#, and I would like it to be able to check for the correct input format. I'm not for sure, but I think my designed loop is not checking the type of input, just what char is entered. I know I could use a try-catch block, but shouldn't you only use exceptions for exceptional situations? This is not an exceptional situation, because I expect that the user would enter an incorrect value. Input validation is not part of my assignment, so the loop is in a homework assignment, but is not part of the homework assignment. Question: Is there a way I could redesign this loop so that it checks for valid input type as well? Code: do { Console.Write("Do you wish to enter another complex number?: (Y or N)"); response = char.Parse(Console.ReadLine()); response = char.ToUpper(response); if (response != 'Y' && response != 'N') Console.WriteLine("You must respond Y or N!"); } while (response != 'Y' && response != 'N'); Thanks!!

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  • mysql: Average over multiple columns in one row, ignoring nulls

    - by Sai Emrys
    I have a large table (of sites) with several numeric columns - say a through f. (These are site rankings from different organizations, like alexa, google, quantcast, etc. Each has a different range and format; they're straight dumps from the outside DBs.) For many of the records, one or more of these columns is null, because the outside DB doesn't have data for it. They all cover different subsets of my DB. I want column t to be their weighted average (each of a..f have static weights which I assign), ignoring null values (which can occur in any of them), except being null if they're all null. I would prefer to do this with a simple SQL calculation, rather than doing it in app code or using some huge ugly nested if block to handle every permutation of nulls. (Given that I have an increasing number of columns to average over as I add in more outside DB sources, this would be exponentially more ugly and bug-prone.) I'd use AVG but that's only for group by, and this is w/in one record. The data is semantically nullable, and I don't want to average in some "average" value in place of the nulls; I want to only be counting the columns for which data is there. Is there a good way to do this? Ideally, what I want is something like UPDATE sites SET t = AVG(a*a_weight,b*b_weight,...) where any null values are just ignored and no grouping is happening.

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  • viewstack causing error 1065 variable not defined issue?

    - by jason
    I've got an flex application where I have a left side TREE control and a viewstack on the right and when someone selects the tree it loads the named viewstack based on the hidden node value of the XML of the tree. But it's throwing a error 1065 variable not defined on a viewstack which worked on the last browser refresh/reload. It's not related to a particular viewstack from what I can tell it just seems to throw the error on certain render events. I've tried to use creationpolicy="all" on the viewstack but it seems to not be of any help. public function treeChanged(event:Event):void { selectedNode=Tree(event.target).selectedItem as XML; //trace(selectedNode.@hidden); //Alert.show([email protected]() + " *"); if([email protected]() == '' || [email protected]() == null){ //Alert.show("NULL !"); return; } mainviewstack.selectedChild = Container(mainviewstack.getChildByName([email protected]())); //Container(mainviewstack.getChildByName(selectedNode.@hidden)); If I add in an alert box before the getchildbyname option the viewstack has time to render and everything works fine, so it leads me to believe the app is not giving it enough time to load the viewstack?

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