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  • django hidden field error

    - by dana
    hi, there, i'm building a message system for a virtual community, but i can't take the userprofile id i have in views.py def save_message(request): if request.method == 'POST': form = MessageForm(request.POST) if form.is_valid(): new_obj = form.save(commit=False) new_obj.sender = request.user u = UserProfile.objects.get(request.POST['userprofile_id']) new_obj.owner = u new_obj.save() return HttpResponseRedirect('.') else: form = MessageForm() return render_to_response('messages/messages.html', { 'form': form, }, context_instance=RequestContext(request)) and the template: {% block primary %} <form action="." method="post"> {{ form.as_p }} <p><input type="hidden" value="{{ userprofile.id }}" name = "owner" /></p> <p><input type="submit" value="Send Message!" /></p> </form> {% endblock %} forms.py: class MessageForm(ModelForm): class Meta: model = Messages fields = ['message'] models.py: class Messages(models.Model): message = models.CharField(max_length = 300) read = models.BooleanField(default=False) owner = models.ForeignKey(UserProfile) sender = models.ForeignKey(User) I don't figure out why i get this error,since i'm just trying to get the profileId of a user, using a hiddeen field. the error is: Key 'UserProfile_id' not found in <QueryDict: {u'owner': [u''], u'message': [u'fdghjkl']}> and i'm getting it after i fill out the message text field. Thanks!

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  • Cast errors with IXmlSerializable

    - by Nathan
    I am trying to use the IXmlSerializable interface to deserialize an Object (I am using it because I need specific control over what gets deserialized and what does not. See my previous question for more information). However, I'm stumped as to the error message I get. Below is the error message I get (I have changed some names for clarity): An unhandled exception of type 'System.InvalidCastException' occurred in App.exe Additional information: Unable to cast object of type 'System.Xml.XmlNode[]' to type 'MyObject'. MyObject has all the correct methods defined for the interface, and regardless of what I put in the method body for ReadXml() I still get this error. It doesn't matter if it has my implementation code or if it's just blank. I did some googling and found an error that looks similar to this involving polymorphic objects that implement IXmlSerializable. However, my class does not inherit from any others (besides Object). I suspected this may be an issue because I never reference XmlNode any other time in my code. Microsoft describes a solution to the polymorphism error: https://connect.microsoft.com/VisualStudio/feedback/details/422577/incorrect-deserialization-of-polymorphic-type-that-implements-ixmlserializable?wa=wsignin1.0#details The code the error occurs at is as follows. The object to be read back in is an ArrayList of "MyObjects" IO::FileStream ^fs = gcnew IO::FileStream(filename, IO::FileMode::Open); array<System::Type^>^ extraTypes = gcnew array<System::Type^>(1); extraTypes[0] = MyObject::typeid; XmlSerializer ^xmlser = gcnew XmlSerializer(ArrayList::typeid, extraTypes); System::Object ^obj; obj = xmlser->Deserialize(fs); fs->Close(); ArrayList ^al = safe_cast<ArrayList^>(obj); MyObject ^objs; for each(objs in al) //Error occurs here { //do some processing } Thanks for reading and for any help.

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  • LGPL library with plugins of varied licenses

    - by Chris
    Note: "Plugins" here refers to shared objects that are accessed via dlopen() and friends. I'm writing a library that I'm planning on releasing under the LGPL. Its functionality can be extended (supporting new audio file formats, specifically) through plugins. I'm planning on creating an exception to the LGPL for this library so that plugins can be released under any license. So far so good. I've written a number of plugins already, some of which use LGPL and some of which use GPL libraries. I'm wary of releasing them with the main library, however, due to licensing issues. The LGPL-based ones would generally be fine, but for my "any license" clause. Would distributing these LGPL-based plugins with the library require the consent of the other license holders to create this exception? Along the same lines, would the inclusion of GPL-based plugins with my library force the whole thing to go GPL? I could also release the plugins separately. The advantage, I presume, is that the plugins an d library will now not be distributed together, creating more separation. But this seems to be no different, really, in the end. Boiled down: Can I include, with my LGPL library, plugins of varied licenses? If not, is it really any different releasing them separately? And if so, there's no real need to create an exception for non-LGPL plugins, is there? It's LGPL or nothing. I'd prefer asking a lawyer, of course, but this is just a hobby and I can't afford to hire a lawyer when I don't expect or want monetary compensation. I'm just hoping others have been in similar situations and have insight.

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  • Finding the left-most and right-most points of a list. std::find_if the right way to go?

    - by Tom
    Hi, I have a list of Point objects, (each one with x,y properties) and would like to find the left-most and right-most points. I've been trying to do it with find_if, but i'm not sure its the way to go, because i can't seem to pass a comparator instance. Is find_if the way to go? Seems not. So, is there an algorithm in <algorithm> to achieve this? Thanks in advance. #include <iostream> #include <list> #include <algorithm> using namespace std; typedef struct Point{ float x; float y; } Point; bool left(Point& p1,Point& p2) { return p1.x < p2.x; } int main(){ Point p1 ={-1,0}; Point p2 ={1,0}; Point p3 ={5,0}; Point p4 ={7,0}; list <Point> points; points.push_back(p1); points.push_back(p2); points.push_back(p3); points.push_back(p4); //Should return an interator to p1. find_if(points.begin(),points.end(),left); return 0; }

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  • ConcurrentLinkedQueue$Node remains in heap after remove()

    - by action8
    I have a multithreaded app writing and reading a ConcurrentLinkedQueue, which is conceptually used to back entries in a list/table. I originally used a ConcurrentHashMap for this, which worked well. A new requirement required tracking the order entries came in, so they could be removed in oldest first order, depending on some conditions. ConcurrentLinkedQueue appeared to be a good choice, and functionally it works well. A configurable amount of entries are held in memory, and when a new entry is offered when the limit is reached, the queue is searched in oldest-first order for one that can be removed. Certain entries are not to be removed by the system and wait for client interaction. What appears to be happening is I have an entry at the front of the queue that occurred, say 100K entries ago. The queue appears to have the limited number of configured entries (size() == 100), but when profiling, I found that there were ~100K ConcurrentLinkedQueue$Node objects in memory. This appears to be by design, just glancing at the source for ConcurrentLinkedQueue, a remove merely removes the reference to the object being stored but leaves the linked list in place for iteration. Finally my question: Is there a "better" lazy way to handle a collection of this nature? I love the speed of the ConcurrentLinkedQueue, I just cant afford the unbounded leak that appears to be possible in this case. If not, it seems like I'd have to create a second structure to track order and may have the same issues, plus a synchronization concern.

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  • How can I use Hibernate Criteria's to query nested tables?

    - by cbmeeks
    I've looked all over SO and Google but I guess I'm not using the right search terms or something. Anyway, say I have three tables: Companies ----------------------------------------- id name user_id Users ----------------------------------------- id username usertype_id UserTypes ----------------------------------------- id typeofuser So ACME would be a company, it would have a user Moe and Moe would be a usertype of Stooge. In SQL, I would do something like: select * from companies c join users u on (u.id = c.user_id) join usertypes ut on (ut.id = u.usertype_id) where ut.typeofuser = 'Stooge' But I can't seem to figure out how to do that in a Criteria. I have tried: Criteria crit = io.getSession().createCriteria(Company.class); List<Company> list = crit.createCriteria("users") .createCriteria("usertypes") .add(Restriction.eq("typeofuser", "Stooge").list(); But I get back way too many records. And the results don't even come close to being accurate. I've also tried: Criteria crit = io.getSession().createCriteria(Company.class); List<Company> list = crit.createAlias("users", "u") .createAlias("u.usertypes", "ut") .add(Restriction.eq("ut.typeofuser", "Stooge").list(); Seems to bring back the exact same result set. I actually have read the user manual. And when I nest only one level deep (ie, searching by users is fine) but when I get two layers deep, I can't quite get it. And the manual is no help. I just can't relate cats and kittens to business objects. Maybe they should use cats, kittens and fleas? :-/ Thanks for any suggestions.

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  • wscript.shell running file with space in path with PHP

    - by ermac2014
    I was trying to use wscript.shell through COM objects with php to pass some cmd commands to cURL library (the DOS version). here is what I use to perform this task: function windExec($cmd,$mode=''){ // Setup the command to run from "run" $cmdline = "cmd /C $cmd"; // set-up the output and mode if ($mode=='FG'){ $outputfile = uniqid(time()) . ".txt"; $cmdline .= " > $outputfile"; $m = true; } else $m = false; // Make a new instance of the COM object $WshShell = new COM("WScript.Shell"); // Make the command window but dont show it. $oExec = $WshShell->Run($cmdline, 0, $m); if ($outputfile){ // Read the tmp file. $retStr = file_get_contents($outputfile); // Delete the temp_file. unlink($outputfile); } else $retStr = ""; return $retStr; } now when I run this function like: windExec("\"C:/Documents and Settings/ermac/Desktop/my project/curl\" http://www.google.com/", 'FG'); curl doesn't run because there is a problem with the path. but when I remove the spaces from the path it works great. windExec("\"C:/curl\" http://www.google.com/", 'FG'); so my question is how can I escape these spaces in wscript.shell commands? is there anyway I can fix this? thanks in advance :)

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  • How to use SendMessage to another form in same app

    - by Robert Frank
    I've been trying to get this to work for some time now and can't figure it out. Probably obvious once you know it. I simply want a non-modal form (or perhaps an instantiated non-TForm class) to send a message to the application's main form. I can make the main form send a message to itself and receive (announcing with a beep) But, I can't seem to have other objects send messages to the main form. I'm using WM_MY_MESSAGE = WM_APP + 200; What should the first argument of the SendMessage be to send a message to the main form? Even sending it to Application.MainForm.Handle doesn't seem to work. The reason I need to do this is that the modal form has a slider that another form (#2) needs to know when it changes. Notifying the other form via a callback procedure was making it sluggish as form #2 did some work before returning from the call. Is having a modal form send a windows message to the main form a reasonable way to avoid this?

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  • C# reflection instantiation

    - by NickLarsen
    I am currently trying to create a generic instance factory for which takes an interface as the generic parameter (enforced in the constructor) and then lets you get instantiated objects which implement that interface from all types in all loaded assemblies. The current implementation is as follows:     public class InstantiationFactory     {         protected Type Type { get; set; }         public InstantiationFactory()         {             this.Type = typeof(T);             if (!this.Type.IsInterface)             {                 // is there a more descriptive exception to throw?                 throw new ArgumentException(/* Crafty message */);             }         }         public IEnumerable GetLoadedTypes()         {             // this line of code found in other stack overflow questions             var types = AppDomain.CurrentDomain.GetAssemblies()                 .SelectMany(a = a.GetTypes())                 .Where(/* lambda to identify instantiable types which implement this interface */);             return types;         }         public IEnumerable GetImplementations(IEnumerable types)         {             var implementations = types.Where(/* lambda to identify instantiable types which implement this interface */                 .Select(x = CreateInstance(x));             return implementations;         }         public IEnumerable GetLoadedImplementations()         {             var loadedTypes = GetLoadedTypes();             var implementations = GetImplementations(loadedTypes);             return implementations;         }         private T CreateInstance(Type type)         {             T instance = default(T);             var constructor = type.GetConstructor(Type.EmptyTypes);             if (/* valid to instantiate test */)             {                 object constructed = constructor.Invoke(null);                 instance = (T)constructed;             }             return instance;         }     } It seems useful to me to have my CreateInstance(Type) function implemented as an extension method so I can reuse it later and simplify the code of my factory, but I can't figure out how to return a strongly typed value from that extension method. I realize I could just return an object:     public static class TypeExtensions     {         public object CreateInstance(this Type type)         {             var constructor = type.GetConstructor(Type.EmptyTypes);             return /* valid to instantiate test */ ? constructor.Invoke(null) : null;         }     } Is it possible to have an extension method create a signature per instance of the type it extends? My perfect code would be this, which avoids having to cast the result of the call to CreateInstance():     Type type = typeof(MyParameterlessConstructorImplementingType);     MyParameterlessConstructorImplementingType usable = type.CreateInstance();

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  • Is there a tool I can use to generate interfaces and wrappers for object mocking in c#

    - by fostandy
    Given a class like System.Timers.Timer, or ANY managed class (whether user defined, from the .net framework, or some 3rd party library) is there some program I can use to (a) generate an interface based on this class and (b) generate a wrapper for the given class? for example if I have a public class Foo { public object MyProperty { get { ... } set { ... } } public int SomeMethod(object a) { ... } } it will create an interface interface IFoo { object MyProperty { get; set; } int SomeMethod(object a) { ... } } and maybe even a wrapper class FooWrap { // something for relay constructor here ... Foo _me; public object MyProperty { get { return _me.MyProperty; } set { _me.MyProperty = value; } } public int SomeMethod(object a) { return _me.SomeMethod(); } } Obviously there's stuff I haven't thought about like events, generics etc. I want a DWIMNWIS-PSICHTO(-Plus-Stuff-I-Clearly-Haven't-Thought-Of). I'm aware resharper can be used to extract an interface but I've only been able to use this on my own classes. Aside: Wow, it is amazing how simply becoming accustomed to a previously 'unacceptable' idea eventually gives it legitimacy. A year ago the idea of having to create interfaces for all objects I want to mock and adopting an injection framework would have seemed like the height of madness. It turns out that while it's not quite death and taxes, it is sparta. I am aware of and have used typemock. It certainly is the work of elvish wizards. One day when $800 does not seem like quite so much money I intend to buy it.

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  • Recommendations of a high volume log event viewer in a Java enviroment

    - by Thorbjørn Ravn Andersen
    I am in a situation where I would like to accept a LOT of log events controlled by me - notably the logging agent I am preparing for slf4j - and then analyze them interactively. I am not as such interested in a facility that presents formatted log files, but one that can accept log events as objects and allow me to sort and display on e.g. threads and timelines etc. Chainsaw could maybe be an option but is currently not compatible with logback which I use for technical reasons. Is there any project with stand alone viewers or embedded in an IDE which would be suitable for this kind of log handling. I am aware that I am approaching what might be suitable for a profiler, so if there is a profiler projekt suitable for this kind of data acquisition and display where I can feed the event pipe, I would like to hear about it). Thanks for all feedback Update 2009-03-19: I have found that there is not a log viewer which allows me to see what I would like (a visual display of events with coordinates determined by day and time, etc), so I have decided to create a very terse XML format derived from the log4j XMLLayout adapted to be as readable as possible while still being valid XML-snippets, and then use the Microsoft LogParser to extract the information I need for postprocessing in other tools.

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  • Calculate rotation between two Vector2s around a pivot

    - by Nick
    Hello all. After a good long Sunday google I am going to have to hang my head in shame and ask the question... What I have is a pivot vector2, a "Previous" vector2 and a "Current" vector2. I would like to be able to calculate the rotation in radians between them. A slight complication is the fact that the pivot may moved between previous and current but ill deal with the offsetting as a separate issue if you don't have the time to bring that into the fold. To clarify, an object which has two vectors, a pivot and a base ... the pivot sitting in the centre and the base at the bottom is rotated around an external pivot. I need to work out the rotation of the object itself around its centre using the two mentioned vectors. Very big thanks to anyone that can help. Background to problem I have a game where an object is rotated around an external pivot. By using using two points (one in the centre, one at the base of the object) I am wanting to to work out the rotation that needs to be applied to the objects sprite around its centre to conform to the larger rotation that has been applied.

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  • 3 tier application pattern suggestion

    - by Maxim Gershkovich
    I have attempted to make my first 3 tier application. In the process I have run into one problem I am yet to find an optimal solution for. Basically all my objects use an IFillable interface which forces the implementation of a sub as follows Public Sub Fill(ByVal Datareader As Data.IDataReader) Implements IFillable.Fill This sub then expects the Ids from the datareader will be identical to the properties of the object as such. Me.m_StockID = Datareader.GetGuid(Datareader.GetOrdinal("StockID")) In the end I end up with a datalayer that looks something like this. Public Shared Function GetStockByID(ByVal ConnectionString As String, ByVal StockID As Guid) As Stock Dim res As New Stock Using sqlConn As New SqlConnection(ConnectionString) sqlConn.Open() res.Fill(StockDataLayer.GetStockByIDQuery(sqlConn, StockID)) End Using Return res End Function Mostly this pattern seems to make sense. However my problem is, lets say I want to implement a property for Stock called StockBarcodeList. Under the above mentioned pattern any way I implement this property I will need to pass a connectionstring to it which obviously breaks my attempt at layer separation. Does anyone have any suggestions on how I might be able to solve this problem or am I going about this the completely wrong way? Does anyone have any suggestions on how I might improve my implementation? Please note however I am deliberately trying to avoid using the dataset in any form.

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  • Multiple calls to data service from SL3?

    - by Chris
    I have an SL3 that makes asynchronous calls to a data service. Basically, there is a treeview that is bound to a collection of objects. The idea is that as a user selects a specific treeviewitem, a call is made to the data service, with a parameter specific to the selected treeviewitem being passed to the corresponding web method in the data service. The data service returns data back to the SL3 client, and the client presents the data to the user. This works well. The problem is that when users start to navigate through the treeview using the arrow keys on their keyboard, they could press the down arrow key, for example, 10 times, and 10 calls will be made to the data service, and then each of the 10 items will be displayed to the user momentarily, until finishing with the data for the most recently selected treeview item. So - onto the question. How can I put in some form of delay, to allow someone to navigate quickly through a treeview, then, once then stop at a certain treeviewitem, a call is made to the data service? Thanks for any suggestions. Chris

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  • Get string value of class propery names in Objective-C

    - by Flash84x
    I have the following class definition. Contact.h #import <CoreData/CoreData.h> @interface Contact : NSManagedObject { } @property (nonatomic, retain) NSString * City; @property (nonatomic, retain) NSDate * LastUpdated; @property (nonatomic, retain) NSString * Country; @property (nonatomic, retain) NSString * Email; @property (nonatomic, retain) NSNumber * Id; @property (nonatomic, retain) NSString * ContactNotes; @property (nonatomic, retain) NSString * State; @property (nonatomic, retain) NSString * StreetAddress2; @property (nonatomic, retain) NSDate * DateCreated; @property (nonatomic, retain) NSString * FirstName; @property (nonatomic, retain) NSString * Phone1; @property (nonatomic, retain) NSString * PostalCode; @property (nonatomic, retain) NSString * Website; @property (nonatomic, retain) NSString * StreetAddress1; @property (nonatomic, retain) NSString * LastName; @end Is it possible to obtain an array of NSString objects with all of the properties by name? Array would look like this... [@"City", @"LastUpdated", @"Country", .... ]

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  • Django caching seems to be causing problems

    - by Issy
    Hey guys, i have just implemented the Django Cache Local Memory back end in some my code, however it seems to be causing a problem. I get the following error when trying to view the site (With Debug On): Traceback (most recent call last): File "/usr/lib/python2.6/dist-packages/django/core/servers/basehttp.py", line 279, in run self.result = application(self.environ, self.start_response) File "/usr/lib/python2.6/dist-packages/django/core/servers/basehttp.py", line 651, in __call__ return self.application(environ, start_response) File "/usr/lib/python2.6/dist-packages/django/core/handlers/wsgi.py", line 245, in __call__ response = middleware_method(request, response) File "/usr/lib/python2.6/dist-packages/django/middleware/cache.py", line 91, in process_response patch_response_headers(response, timeout) File "/usr/lib/python2.6/dist-packages/django/utils/cache.py", line 112, in patch_response_headers response['Expires'] = http_date(time.time() + cache_timeout) TypeError: unsupported operand type(s) for +: 'float' and 'str' I have checked my code, for caching everything seems to be ok. For example, i have the following in my middleware. MIDDLEWARE_CLASSES = ( 'django.contrib.sessions.middleware.SessionMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware', 'django.middleware.cache.UpdateCacheMiddleware', 'django.middleware.common.CommonMiddleware', 'django.middleware.cache.FetchFromCacheMiddleware', 'django.contrib.flatpages.middleware.FlatpageFallbackMiddleware', ) My settings for Cache: CACHE_BACKEND = 'locmem://' CACHE_MIDDLEWARE_SECONDS = '3600' CACHE_MIDDLEWARE_KEY_PREFIX = 'za' CACHE_MIDDLEWARE_ANONYMOUS_ONLY = True And some of my code (template tag): def get_featured_images(): """ provides featured images """ cache_key = 'featured_images' images = cache.get(cache_key) if images is None: images = FeaturedImage.objects.all().filter(enabled=True)[:5] cache.set(cache_key, images) return {'images': images} Any idea what could be the problem, from the error message below it looks like there's an issue in django's cache.py?

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  • PHP: MVC and Model

    - by Pirkka
    Hello I`ve been wondering this one thing about creating models. If I make for example Page model. Is it the both: It can retrieve one row from the table or all the rows. Somehow Im mixing the objects and the database. I have thought it like this: I would have to make a Page-class that would represent one row in the table. It also would have all the basic CRUD-methods. Then I would have to do a Pages-class (somekind of collection) that would retrieve rows from the table and instantiate a Page object from each row. Is this kind of weird? If someone could explain to me the idea of model throughout.. Im again confused. Maybe Im thinking the whole OOP too difficult.. And by the way this forum is great. Hopefully people will just understand my problems. Heh. I was a long time procedural style programmer and now in 3 months I have dived into OOP and MVC and PHP frameworks and I just get more excited day by day when I explore this stuff!

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  • constructor function's object literal returns toString() method but no other method

    - by JohnMerlino
    I'm very confused with javascript methods defined in objects and the "this" keyword. In the below example, the toString() method is invoked when Mammal object instantiated: function Mammal(name){ this.name=name; this.toString = function(){ return '[Mammal "'+this.name+'"]'; } } var someAnimal = new Mammal('Mr. Biggles'); alert('someAnimal is '+someAnimal); Despite the fact that the toString() method is not invoked on the object someAnimal like this: alert('someAnimal is '+someAnimal.toString()); It still returns 'someAnimal is [Mammal "Mr. Biggles"]' . That doesn't make sense to me because the toString() function is not being called anywhere. Then to add even more confusion, if I change the toString() method to a method I make up such as random(): function Mammal(name){ this.name=name; this.random = function(){ return Math.floor(Math.random() * 15); } } var someAnimal = new Mammal('Mr. Biggles'); alert(someAnimal); It completely ignores the random method (despite the fact that it is defined the same way was the toString() method was) and returns: [object object] Another issue I'm having trouble understanding with inheritance is the value of "this". For example, in the below example function person(w,h){ width.width = w; width.height = h; } function man(w,h,s) { person.call(this, w, h); this.sex = s; } "this" keyword is being send to the person object clearly. However, does "this" refer to the subclass (man) or the super class (person) when the person object receives it? Thanks for clearing up any of the confusion I have with inheritance and object literals in javascript.

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  • Haskell: "how much" of a type should functions receive? and avoiding complete "reconstruction"

    - by L01man
    I've got these data types: data PointPlus = PointPlus { coords :: Point , velocity :: Vector } deriving (Eq) data BodyGeo = BodyGeo { pointPlus :: PointPlus , size :: Point } deriving (Eq) data Body = Body { geo :: BodyGeo , pict :: Color } deriving (Eq) It's the base datatype for characters, enemies, objects, etc. in my game (well, I just have two rectangles as the player and the ground right now :p). When a key, the characters moves right, left or jumps by changing its velocity. Moving is done by adding the velocity to the coords. Currently, it's written as follows: move (PointPlus (x, y) (xi, yi)) = PointPlus (x + xi, y + yi) (xi, yi) I'm just taking the PointPlus part of my Body and not the entire Body, otherwise it would be: move (Body (BodyGeo (PointPlus (x, y) (xi, yi)) wh) col) = (Body (BodyGeo (PointPlus (x + xi, y + yi) (xi, yi)) wh) col) Is the first version of move better? Anyway, if move only changes PointPlus, there must be another function that calls it inside a new Body. I explain: there's a function update which is called to update the game state; it is passed the current game state, a single Body for now, and returns the updated Body. update (Body (BodyGeo (PointPlus xy (xi, yi)) wh) pict) = (Body (BodyGeo (move (PointPlus xy (xi, yi))) wh) pict) That tickles me. Everything is kept the same within Body except the PointPlus. Is there a way to avoid this complete "reconstruction" by hand? Like in: update body = backInBody $ move $ pointPlus body Without having to define backInBody, of course.

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  • Using ember-resource with couchdb - how can i save my documents?

    - by Thomas Herrmann
    I am implementing an application using ember.js and couchdb. I choose ember-resource as database access layer because it nicely supports nested JSON documents. Since couchdb uses the attribute _rev for optimistic locking in every document, this attribute has to be updated in my application after saving the data to the couchdb. My idea to implement this is to reload the data right after saving to the database and get the new _rev back with the rest of the document. Here is my code for this: // Since we use CouchDB, we have to make sure that we invalidate and re-fetch // every document right after saving it. CouchDB uses an optimistic locking // scheme based on the attribute "_rev" in the documents, so we reload it in // order to have the correct _rev value. didSave: function() { this._super.apply(this, arguments); this.forceReload(); }, // reload resource after save is done, expire to make reload really do something forceReload: function() { this.expire(); // Everything OK up to this location Ember.run.next(this, function() { this.fetch() // Sub-Document is reset here, and *not* refetched! .fail(function(error) { App.displayError(error); }) .done(function() { App.log("App.Resource.forceReload fetch done, got revision " + self.get('_rev')); }); }); } This works for most cases, but if i have a nested model, the sub-model is replaced with the old version of the data just before the fetch is executed! Interestingly enough, the correct (updated) data is stored in the database and the wrong (old) data is in the memory model after the fetch, although the _rev attribut is correct (as well as all attributes of the main object). Here is a part of my object definition: App.TaskDefinition = App.Resource.define({ url: App.dbPrefix + 'courseware', schema: { id: String, _rev: String, type: String, name: String, comment: String, task: { type: 'App.Task', nested: true } } }); App.Task = App.Resource.define({ schema: { id: String, title: String, description: String, startImmediate: Boolean, holdOnComment: Boolean, ..... // other attributes and sub-objects } }); Any ideas where the problem might be? Thank's a lot for any suggestion! Kind regards, Thomas

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  • What are the options for overriding Django's cascading delete behaviour?

    - by Tom
    Django models generally handle the ON DELETE CASCADE behaviour quite adequately (in a way that works on databases that don't support it natively.) However, I'm struggling to discover what is the best way to override this behaviour where it is not appropriate, in the following scenarios for example: ON DELETE RESTRICT (i.e. prevent deleting an object if it has child records) ON DELETE SET NULL (i.e. don't delete a child record, but set it's parent key to NULL instead to break the relationship) Update other related data when a record is deleted (e.g. deleting an uploaded image file) The following are the potential ways to achieve these that I am aware of: Override the model's delete() method. While this sort of works, it is sidestepped when the records are deleted via a QuerySet. Also, every model's delete() must be overridden to make sure Django's code is never called and super() can't be called as it may use a QuerySet to delete child objects. Use signals. This seems to be ideal as they are called when directly deleting the model or deleting via a QuerySet. However, there is no possibility to prevent a child object from being deleted so it is not usable to implement ON CASCADE RESTRICT or SET NULL. Use a database engine that handles this properly (what does Django do in this case?) Wait until Django supports it (and live with bugs until then...) It seems like the first option is the only viable one, but it's ugly, throws the baby out with the bath water, and risks missing something when a new model/relation is added. Am I missing something? Any recommendations?

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  • How to std::find using a Compare object?

    - by dehmann
    I am confused about the interface of std::find. Why doesn't it take a Compare object that tells it how to compare two objects? If I could pass a Compare object I could make the following code work, where I would like to compare by value, instead of just comparing the pointer values directly: typedef std::vector<std::string*> Vec; Vec vec; std::string* s1 = new std::string("foo"); std::string* s2 = new std::string("foo"); vec.push_back(s1); Vec::const_iterator found = std::find(vec.begin(), vec.end(), s2); // not found, obviously, because I can't tell it to compare by value delete s1; delete s2; Is the following the recommended way to do it? template<class T> struct MyEqualsByVal { const T& x_; MyEqualsByVal(const T& x) : x_(x) {} bool operator()(const T& y) const { return *x_ == *y; } }; // ... vec.push_back(s1); Vec::const_iterator found = std::find_if(vec.begin(), vec.end(), MyEqualsByVal<std::string*>(s2)); // OK, will find "foo"

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  • What is the performance penalty of XML data type in SQL Server when compared to NVARCHAR(MAX)?

    - by Piotr Owsiak
    I have a DB that is going to keep log entries. One of the columns in the log table contains serialized (to XML) objects and a guy on my team proposed to go with XML data type rather than NVARCHAR(MAX). This table will have logs kept "forever" (archiving some very old entries may be considered in the future). I'm a little worried about the CPU overhead, but I'm even more worried that DB can grow faster (FoxyBOA from the referenced question got 70% bigger DB when using XML). I have read this question http://stackoverflow.com/questions/514827/microsoft-sql-server-2005-2008-xml-vs-text-varchar-data-type and it gave me some ideas but I am particulairly interrested in clarification on whether the DB size increases or decreases. Can you please share your insight/experiences in that matter. BTW. I don't currently have any need to depend on XML features within SQL Server (there's nearly zero advantage to me in the specific case). Ocasionally log entries will be extracted, but I prefer to handle the XML using .NET (either by writing a small client or using a function defined in a .NET assembly).

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  • Is My DataTable Snippet Written Correctly?

    - by user311509
    public static DataTable GetDataTable(SqlCommand sqlCmd) { DataTable tblMyTable = new DataTable(); DataSet myDataSet = new DataSet(); try { //1. Create connection mSqlConnection = new SqlConnection(mStrConnection); //2. Open connection mSqlConnection.Open(); mSqlCommand = new SqlCommand(); mSqlCommand = sqlCmd; //3. Assign Connection mSqlCommand.Connection = mSqlConnection; //4. Create/Set DataAdapter mSqlDataAdapter = new SqlDataAdapter(); mSqlDataAdapter.SelectCommand = mSqlCommand; //5. Populate DataSet mSqlDataAdapter.Fill(myDataSet, "DataSet"); tblMyTable = myDataSet.Tables[0]; } catch (Exception ex) { } finally { //6. Clear objects if ((mSqlDataAdapter != null)) { mSqlDataAdapter.Dispose(); } if ((mSqlCommand != null)) { mSqlCommand.Dispose(); } if ((mSqlConnection != null)) { mSqlConnection.Close(); mSqlConnection.Dispose(); } } //7. Return DataSet return tblMyTable; } I use the above code to return records from database. The above snippet would run in web application which expected to have around 5000 visitors daily. The records returned reach 20,000 or over. The returned records are viewed (read-only) in paged GridView. Would it be better to use DataReader instead of DataTable? NOTE: two columns in the GridView are hyperlinked.

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  • How do JVM's implicit memory barriers behave when chaining constructors

    - by Joonas Pulakka
    Referring to my earlier question on incompletely constructed objects, I have a second question. As Jon Skeet pointed out, there's an implicit memory barrier in the end of a constructor that makes sure that final fields are visible to all threads. But what if a constructor calls another constructor; is there such a memory barrier in the end of each of them, or only in one being called from outside? That is, when the "wrong" solution is: public class ThisEscape { public ThisEscape(EventSource source) { source.registerListener( new EventListener() { public void onEvent(Event e) { doSomething(e); } }); } } And the correct one would be a factory method version: public class SafeListener { private final EventListener listener; private SafeListener() { listener = new EventListener() { public void onEvent(Event e) { doSomething(e); } } } public static SafeListener newInstance(EventSource source) { SafeListener safe = new SafeListener(); source.registerListener(safe.listener); return safe; } } Would the following work too, or not? public class MyListener { private final EventListener Listener; private MyListener() { listener = new EventListener() { public void onEvent(Event e) { doSomething(e); } } } public MyListener(EventSource source) { this(); source.register(listener); } }

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