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• Save Xml in an Excel cell value causes ComException

  - by mas_oz2k1

  I am trying to save an object (Class1) as string in a cell value. My issue is that from time to time I have a ComException: HRESULT: 0x8007000E (E_OUTOFMEMORY) (It is kind of random but I have not identified any particular pattern yet) when I write the value into a cell. Any ideas will be welcome For illustration purposes: Let Class1 be the class to be converted to an Xml string. (Notice that I removed the xml declaration at the start of the string to avoid having the preamble present- non printable character) <Class1 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" <ElementID HL690375</ElementID </Class1" Class1 myClass = new Class1(); this class is converted to a string s. s= ConvertObjectToXmlString(myClass); then s is assigned to a cell Range r = Application.ActiveCell; r.Value2 = s; Note: (1) If the string is too big, I limit it to 32000 chars and split the string in chunks of 32000 chars and save the chunks in multiple cells. (2) I do not to quote the string before adding to a cell. Do I need to? If so how it can be done? (3) All object contents are English. (4) C# code sample will be great but VB.net code is OK.

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• Thread-safety of read-only memory access

  - by Edmund

  I've implemented the Barnes-Hut gravity algorithm in C as follows: Build a tree of clustered stars. For each star, traverse the tree and apply the gravitational forces from each applicable node. Update the star velocities and positions. Stage 2 is the most expensive stage, and so is implemented in parallel by dividing the set of stars. E.g. with 1000 stars and 2 threads, I have one thread processing the first 500 stars and the second thread processing the second 500. In practice this works: it speeds the computation by about 30% with two threads on a two-core machine, compared to the non-threaded version. Additionally, it yields the same numerical results as the original non-threaded version. My concern is that the two threads are accessing the same resource (namely, the tree) simultaneously. I have not added any synchronisation to the thread workers, so it's likely they will attempt to read from the same location at some point. Although access to the tree is strictly read-only I am not 100% sure it's safe. It has worked when I've tested it but I know this is no guarantee of correctness! Questions Do I need to make a private copy of the tree for each thread? Even if it is safe, are there performance problems of accessing the same memory from multiple threads?

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• Insert or Update using Oracle and PL/SQL

  - by Shane

  I have a PL/SQL function that performs an update/insert on an Oracle database that maintains a target total and returns the difference between the existing value and the new value. Here is the code I have so far: FUNCTION calcTargetTotal(accountId varchar2, newTotal numeric ) RETURN number is oldTotal numeric(20,6); difference numeric(20,6); begin difference := 0; begin select value into oldTotal from target_total WHERE account_id = accountId for update of value; if (oldTotal != newTotal) then update target_total set value = newTotal WHERE account_id = accountId difference := newTotal - oldTotal; end if; exception when NO_DATA_FOUND then begin difference := newTotal; insert into target_total ( account_id, value ) values ( accountId, newTotal ); -- sometimes a race condition occurs and this stmt fails -- in those cases try to update again exception when DUP_VAL_ON_INDEX then begin difference := 0; select value into oldTotal from target_total WHERE account_id = accountId for update of value; if (oldTotal != newTotal) then update target_total set value = newTotal WHERE account_id = accountId difference := newTotal - oldTotal; end if; end; end; end; return difference end calcTargetTotal; This works as expected in unit tests with multiple threads never failing. However when loaded on a live system we have seen this fail with a stack trace looking like this: ORA-01403: no data found ORA-00001: unique constraint () violated ORA-01403: no data found The line numbers (which I have removed since they are meaningless out of context) verify that the first update fails due to no data, the insert fail due to uniqueness, and the 2nd update is failing with no data, which should be impossible. From what I have read on other thread a MERGE statement is also not atomic and could suffer similar problems. Does anyone have any ideas how to prevent this from occurring?

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• Host WCF in MVC2 Site

  - by Basiclife

  Hi, We've got a very large, complex MVC2 website. We want to add an API for some internal tools and decided to use WCF. Ideally, we want MVC itself to host the WCF service. Reasons include: Although there's multiple tiers to the application, some functionality we'd like in the API requires the website itself (e.g. formatting emails). We use TFS to auto-build (continuous integration) and deploy - The less we need to modify the build and release mechanism the better We use the Unity container and Inversion of Control throughout the application. Being part of the Website would allow us to re-use configuration classes and other helper methods. I've written a custom ServiceBehavior which in turn has a custom InstanceProvider - This allows me to instantiate and configure a container which is then used to service all requests for class instances from WCF. So my question is; Is it possible to host a WCF service from within MVC itself? I've only had experience in Services / Standard Asp.Net websites before and didn't realise MVC2 might be different until I actually tried to wire it into the config and nothing happened. After some googling, there don't seem to be many references to doing this - so thought I'd ask here.

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• SL3 Grid RowDefinition Height Problem

  - by Chris

  I have a parent grid that contains multiple row definitions, all of which have their height set to 'auto'. Within the parent grid are individual grids - each individual grid contains a custom content control. When the custom content control loads, the height may increase. What I am noticing is that when the height does increase, the content overlaps with the content in other rows. I have specified the horizontal and vertical alignments - am I missing something? Here is an example: <Grid x:Name="LayoutRoot"> <Grid x:Name="ParentGrid>"> <Grid.RowDefinitions> <RowDefinition Height="Auto"/> <RowDefinition Height="Auto"/> <RowDefinition Height="Auto"/> </Grid.RowDefinitions> <Grid Grid.Row="0"> <CustomContentControl/> </Grid> <Grid Grid.Row="1"> <CustomContentControl/> </Grid> <Grid Grid.Row="2"> <CustomContentControl/> </Grid> </Grid> </Grid>

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• Compare values in serialized column in Doctrine with Query Builder

  - by ReynierPM

  I'm building a FormType for a Symfony2 project but I need some Query Builder on the field since I need to compare some values with the one stored on DB and show the results. This is what I have: .... ->add('servicio', 'entity', array( 'mapped' => false, 'class' => 'ComunBundle:TipoServicio', 'property' => 'nombre', 'required' => true, 'label' => false, 'expanded' => true, 'multiple' => true, 'query_builder' => function (EntityRepository $er) { return $er->createQueryBuilder('ts') ->where('ts.tipo_usuario = (:tipo)') ->setParameter('tipo', 1); } )) .... But tipo_usuario at DB table is stored as serialized text for example: record1: value1 | a:1:{i:0;s:1:"1";} record2: value2 | a:4:{i:0;s:1:"1";i:1;s:1:"2";i:2;s:1:"3";i:3;s:1:"4";} I'll have two different forms (I don't know how to pass the Request to a form) in the first one I'll only show the first record and for the second one the first and second record for example: First form will show: checkbox: value1 Second form will show: checkbox: value1 checkbox: value2 I achieve this? Any help?

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• ASP.NET server data persistence

  - by Wayne Werner

  Hi, I'm not really sure exactly how the question should be phrased, so please be patient if I ask the wrong thing. I'm writing an ASP.NET application using VB as the code behind language. I have a data access class that connects to the DB to run the query (parameterized, of course), and another class to perform the validation tasks - I access this class from my aspx page. What I would like is to be able to store the data server side and wait for the user to choose from a few options based on the validity of the data. But unless my understanding is completely off, having persistent data objects on the server will give problems when multiple users connect? My ultimate goal is that once the data has been validated the end user can't modify it. Currently I'm validating the data, but I still have to retrieve it from the web form AFTER the user says OK, which obviously leaves open the possibility of injecting bad data either accidentally (unlikely) or on purpose (also unlikely for the use, but I'd prefer not to take the chance). So am I completely off in my understanding? If so, can someone point me to a resource that provides some instructions on keeping persistent data on the server, or provide instruction? Thanks!

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• How do I switch out Views in a Cocoa application?

  - by David Garcia

  So I'm beginning to learn how to use Cocoa. I think I've pretty much got it but I'm hung up on creating and switching views. I'm rewriting a game I made a little bit ago for practice. All I want is one window (preferably not resizable) and I want to be able to switch out views for different screens in the game. First, I have the main menu (Start Game, High Scores, Exit). Then I need a window for each screen (Gameplay screen, Highscore screen). What I'm getting confused with is how to design this. I looked up NSViewController thinking it manages views but it doesn't. It only manages one view by loading it really. I don't understand why I'd need to use NSViewController then. Couldn't I just have a window class that contains multiple subclasses of NSView and load them like that? I'm not sure I understand the purpose of the ViewController. Does my Window Class really need to subclass NSWindowController? I was trying to follow the example of Apple's ViewController example and it has a window controller class that's a subclass of NSWindowController. I don't see what the purpose was of subclassing that. All NSWindowController seems to add is - initWithPath:(NSString *)newPath but I fail to see the use in that either when I can just edit the plist file to open the window on start up. Apple's example also has an NSView variable and an NSViewController variable. Don't you only need one variable to store the current view? Thanks in advance guys, I'm really confused as to how this works.

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• Updating target workbook - extracting data from source workbook

  - by Allan

  My question is as follows: I have given a workbook to multiple people. They have this workbook in a folder of their choice. The workbook name is the same for all people, but folder locations vary. Let's assume the common file name is MyData-1.xls. Now I have updated the workbook and want to give it to these people. However when they receive the new one (let's call it MyData-2.xls) I want specific parts of their data pulled from their file (MyData-1) and automatically put into the new one provided (MyData-2). The columns and cells to be copied/imported are identical for both workbooks. Let's assume I want to import cell data (values only) from MyData-1.xls, Sheet 1, cells B8 through C25 ... to ... the same location in the MyData-2.xls workbook. How can I specify in code (possibly attached to a macro driven import data now button) that I want this data brought into this new workbook. I have tried it at my own location by opening the two workbooks and using the copy/paste-special with links process. It works really well, but It seems to create a hard link between the two physical workbooks. I changed the name of the source workbook and it still worked. This makes me believe that there is a "hard link" between the tow and that this will not allow me to give the target (MyData-2.xls) workbook to others and have it find their source workbook.

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• setting write permissions on theme subdirectory?

  - by Scott B

  I've a theme which supports multiple templates, each with a header background image whose color can be set by the site owner via a colorpicker widget in my theme's options panel. This has the effect of opening the background image, recoloring it and resaving it back to the server. I've had zero issues with this routine until recently when a customer installed the theme on a web host whose default read/write permissions are apparently much more restrictive than the norm. In this case, the user was unable to alter the colors of the template images because of the permissions settings. I'm looking for a bit of understanding on what the permissions would need to be (assuming I purposefully set them via script) to allow the logged in wordpress user to write to files under my theme's styles directory. The code I'm using to write to the image file is below... $img = imagecreatefromgif("../wp-content/themes/mytheme/styles/".get_option('my_theme')."/image.gif"); $color = imagecolorallocate($img, $info["red"], $info["green"], $info["blue"]); imagecolorset($img, 0, $info["red"], $info["green"], $info["blue"]); imagegif($img, $path);

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• How to generate a monotone MART ROC in R?

  - by user1521587

  I am using R and applying MART (Alg. for multiple additive regression trees) on a training set to build prediction models. When I look at the ROC curve, it is not monotone. I would be grateful if someone can help me with how I should fix this. I am guessing the issue is that initially, MART generates n trees and if these trees are not the same for all the models I am building, the results will not be comparable. Here are the steps I take: 1) Fix the false-negative cost, c_fn. Let cost = c(0, 1, c_fn, 0). 2) use the following line to build the mart model: mart(x, y, lx, martmode='class', niter=2000, cost.mtx=cost) where x is the matrix of training set variables, y is the observation matrix, lx is the matrix which specifies which of the variables in x is numerical, which one categorical. 3) I predict the test set observations using the mart model found in step 2 using this line: y_pred = martpred(x_test, probs=T) 4) I compute the false-positive and false-negative errors as follows: t = 1/(1+c_fn) %threshold based on Bayes optimal rule where c_fp=1 and c_fn. p_0 = length(which(y_test==1))/dim(y_test)[1] p_01 = sum(1*(y_pred[,2]t & y_test==0))/dim(y_test)[1] p_11 = sum(1*(y_pred[,2]t & y_test==1))/dim(y_test)[1] p_fp = p_01/(1-p_0) p_tp = p_11/p_0 5) repeat step 1-4 for a new false-negative cost.

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• Tree deletion with NHibernate

  - by Tigraine

  Hi, I'm struggling with a little problem and starting to arrive at the conclusion it's simply not possible. I have a Table called Group. As with most of these systems Group has a ParentGroup and a Children collection. So the Table Group looks like this: Group -ID (PK) -Name -ParentId (FK) I did my mappings using FNH AutoMappings, but I had to override the defaults for this: p.References(x => x.Parent) .Column("ParentId") .Cascade.All(); p.HasMany(x => x.Children) .KeyColumn("ParentId") .ForeignKeyCascadeOnDelete() .Cascade.AllDeleteOrphan() .Inverse(); Now, the general idea was to be able to delete a node and all of it's children to be deleted too by NH. So deleting the only root node should basically clear the whole table. I tried first with Cascade.AllDeleteOrphan but that works only for deletion of items from the Children collection, not deletion of the parent. Next I tried ForeignKeyCascadeOnDelete so the operation gets delegated to the Database through on delete cascade. But once I do that MSSql2008 does not allow me to create this constraint, failing with : Introducing FOREIGN KEY constraint 'FKBA21C18E87B9D9F7' on table 'Group' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints. Well, and that's it for me. I guess I'll just loop through the children and delete them one by one, thus doing a N+1. If anyone has a suggestion on how do that more elegantly I'd be eager to hear it.

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• Combining two-part SQL query into one query

  - by user332523

  Hello, I have a SQL query that I'm currently solving by doing two queries. I am wondering if there is a way to do it in a single query that makes it more efficient. Consider two tables: Transaction_Entries table and Transactions, each one defined below: Transactions - id - reference_number (varchar) Transaction_Entries - id - account_id - transaction_id (references Transactions table) Notes: There are multiple transaction entries per transaction. Some transactions are related, and will have the same reference_number string. To get all transaction entries for Account X, then I would do SELECT E.*, T.reference_number FROM Transaction_Entries E JOIN Transactions T ON (E.transaction_id=T.id) where E.account_id = X The next part is the hard part. I want to find all related transactions, regardless of the account id. First I make a list of all the unique reference numbers I found in the previous result set. Then for each one, I can query all the transactions that have that reference number. Assume that I hold all the rows from the previous query in PreviousResultSet UniqueReferenceNumbers = GetUniqueReferenceNumbers(PreviousResultSet) // in Java foreach R in UniqueReferenceNumbers // in Java SELECT * FROM Transaction_Entries where transaction_id IN (SELECT * FROM Transactions WHERE reference_number=R Any suggestions how I can put this into a single efficient query?

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• Creating a method for wrapping a loaded image in a UIImageView

  - by eco_bach

  I have the following un my applicationDidFinishLaunching method UIImage *image2 = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"image2.jpg" ofType:nil]]; view2 = [[UIImageView alloc] initWithImage:image2]; view2.hidden = YES; [containerView addSubview:view2]; I'm simply adding an image to a view. But because I need to add 30-40 images I need to wrap the above in a function (which returns a UIImageView) and then call it from a loop. This is my first attempt at creating the function -(UIImageView)wrapImageInView:(NSString *)imagePath { UIImage *image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:imagePath ofType:nil]]; UIImageView *view = [[UIImageView alloc] initWithImage:image]; view.hidden = YES; } And then to invoke it I have the following so far, for simplicity I am only wrapping 3 images //Create an array and add elements to it NSMutableArray *anArray = [[NSMutableArray alloc] init]; [anArray addObject:@"image1.jpg"]; [anArray addObject:@"image2.jpg"]; [anArray addObject:@"image3.jpg"]; //Use a for each loop to iterate through the array for (NSString *s in anArray) { UIImageView *wrappedImgInView=[self wrapImage:s]; [containerView addSubview:wrappedImgInView]; NSLog(s); } //Release the array [anArray release]; I have 2 general questions 1-Is my approach correct?, ie following best practices, for what I am trying to do (load a multiple number of images(jpgs, pngs, etc.) and adding them to a container view) 2-For this to work properly with a large number of images, do I need to keep my array creation separate from my method invocation? Any other suggestions welcome!

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• Java: design for using many executors services and only few threads

  - by Guillaume

  I need to run in parallel multiple threads to perform some tests. My 'test engine' will have n tests to perform, each one doing k sub-tests. Each test result is stored for a later usage. So I have n*k processes that can be ran concurrently. I'm trying to figure how to use the java concurrent tools efficiently. Right now I have an executor service at test level and n executor service at sub test level. I create my list of Callables for the test level. Each test callable will then create another list of callables for the subtest level. When invoked a test callable will subsequently invoke all subtest callables test 1 subtest a1 subtest ...1 subtest k1 test n subtest a2 subtest ...2 subtest k2 call sequence: test manager create test 1 callable test1 callable create subtest a1 to k1 testn callable create subtest an to kn test manager invoke all test callables test1 callable invoke all subtest a1 to k1 testn callable invoke all subtest an to kn This is working fine, but I have a lot of new treads that are created. I can not share executor service since I need to call 'shutdown' on the executors. My idea to fix this problem is to provide the same fixed size thread pool to each executor service. Do you think it is a good design ? Do I miss something more appropriate/simple for doing this ?

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• Web pages that a long time to load keep on reloading, just on vista on my work n/w...

  - by Ralpharama

  I have a curious problem at work which I've been struggling with since the advent of Windows Vista. We send our own email newsletter out to 40,000+ people once a week. The sending code has been in place for years, it's in classic ASP/VBscript called through a browser and simply loops through each email address, sending it to them. The page takes 40 mins or more to run, so has a big timeout value to allow it to do so. All well and good, suddenly, after Windows Vista is installed on the work PCs, the email sending page behaved oddly - after a period of time it seems to reload the page, endlessly, so the first 20% of our users get multiple copies of the newsletter until we kill the process! If we run the code on an XP machine in the on the same office network, it works fine. If we run it on Vista outside the office, so, say, on my own ISP, then it also works fine! Note, same effect in IE and FF... So, something about my office network and Vista is causing this... I recently re-wrote the newsletter code so it would split the task into chunks of 100 users at a time, hoping this would fix it, but my most recent test shows that the office n/w vista machine once again reloads the same page over any over, even though it takes 1/10th of the time to run... Does anyone have any ideas what it might be, how I can prove it, or, better, how I can get round it? Thanks for your advice :)

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• Performance improvement of client server system

  - by Tanuj

  I have a legacy client server system where the server maintains a record of some data stored in a sqlite database. The data is related to monitoring access patterns of files stored on the server. The client application is basically a remote viewer of the data. When the client is launched, it connects to the server and gets the data from the server to display in a grid view. The data gets updated in real time on the server and the view in the client automatically gets refreshed. There are two problems with the current implementation: When the database gets too big, it takes a lot of time to load the client. What are the best ways to deal with this. One option is to maintain a cache at the client side. How to best implement a cache ? How can the server maintain a diff so that it only sends the diff during the refresh cycle. There can be multiple clients and each client needs to display the latest data available on the server. The server is a windows service daemon. Both the client and the server are implemented in C#

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• php convert european datetime to mysql datetime

  - by Mathlight

  I'm really stuck with this problem. I've got an datetime string like this: 28-06-14 11:01:00 I'm trying to convert it to 2014-06-28 11:01:00 so that i can insert it into the database ( with field type datetime. I've tryed multiple things like this: $datumHolder = new DateTime($data['datum'], new DateTimeZone('Europe/Amsterdam')); $datum1 = $datumHolder -> format("Y-m-d H:i:s"); $datum2 = date( 'Y-m-d', strtotime(str_replace('-', '/', $data['datum']) ) ); $datum3 = DateTime::createFromFormat( 'Y-m-d-:Hi:s', $data['datum']); This is the output i get: datum1: 2028-06-14 11:01:00 datum2: 1970-01-01 And i get an error for datum3: echo "datum3: " . $datum3->format( 'Y-m-d H:i:s'); . '<br />'; Call to a member function format() on a non-object So my question is very clear... What am I doing wrong / how to get this working? Thanks in advantage guys! I know that this question is asked many, many times... But whatever i try, i can't get it working...

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• WCF data services (OData), query with inheritance limitation?

  - by Mathieu Hétu

  Project: WCF Data service using internally EF4 CTP5 Code-First approach. I configured entities with inheritance (TPH). See previous question on this topic: Previous question about multiple entities- same table The mapping works well, and unit test over EF4 confirms that queries runs smoothly. My entities looks like this: ContactBase (abstract) Customer (inherits from ContactBase), this entity has also several Navigation properties toward other entities Resource (inherits from ContactBase) I have configured a discriminator, so both Customer and Resource map to the same table. Again, everythings works fine on the Ef4 point of view (unit tests all greens!) However, when exposing this DBContext over WCF Data services, I get: - CustomerBases sets exposed (Customers and Resources sets seems hidden, is it by design?) - When I query over Odata on Customers, I get this error: Navigation Properties are not supported on derived entity types. Entity Set 'ContactBases' has a instance of type 'CodeFirstNamespace.Customer', which is an derived entity type and has navigation properties. Please remove all the navigation properties from type 'CodeFirstNamespace.Customer'. Stacktrace: at System.Data.Services.Serializers.SyndicationSerializer.WriteObjectProperties(IExpandedResult expanded, Object customObject, ResourceType resourceType, Uri absoluteUri, String relativeUri, SyndicationItem item, DictionaryContent content, EpmSourcePathSegment currentSourceRoot) at System.Data.Services.Serializers.SyndicationSerializer.WriteEntryElement(IExpandedResult expanded, Object element, ResourceType expectedType, Uri absoluteUri, String relativeUri, SyndicationItem target) at System.Data.Services.Serializers.SyndicationSerializer.<DeferredFeedItems>d__b.MoveNext() at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteItems(XmlWriter writer, IEnumerable`1 items, Uri feedBaseUri) at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteFeedTo(XmlWriter writer, SyndicationFeed feed, Boolean isSourceFeed) at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteFeed(XmlWriter writer) at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteTo(XmlWriter writer) at System.Data.Services.Serializers.SyndicationSerializer.WriteTopLevelElements(IExpandedResult expanded, IEnumerator elements, Boolean hasMoved) at System.Data.Services.Serializers.Serializer.WriteRequest(IEnumerator queryResults, Boolean hasMoved) at System.Data.Services.ResponseBodyWriter.Write(Stream stream) Seems like a limitation of WCF Data services... is it? Not much documentation can be found on the web about WCF Data services (OData) and inheritance specifications. How can I overpass this exception? I need these navigation properties on derived entities, and inheritance seems the only way to provide mapping of 2 entites on the same table with Ef4 CTP5... Any thoughts?

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• Start with remoting or with WCF

  - by Sheldon

  Hi. I'm just starting with distributed application development. I need to create (all by myself) an enterprise application for document management. That application will run on an intranet (within the firewall, no internet access is required now, BUT is probably that will be later). The application needs to manage images that will be stored within MySQL Server (as blobs) and those images will be then recovered by the app and eventually one or more of them will be converted to PDF. Performance is the most important non-functional requirement. I have a couple of doubts. What do you suggest to use, .NET Remoting or WCF over TCP-IP (I think second one is the best for the moment I need to expose the business logic over internet, changing the protocol). Where do you suggest to make the transformation of the images to pdf files, I'm using iText. (I have thought to have the business logic stored within the IIS and exposed via WCF, and that business logic to be responsible of getting the images and transforming them to PDF, that because the IIS and the MySQL Server are the same physical machine). I ask about where to do the transformation because the app must be accessible from multiple devices, and for example, for mobile devices, the pdf maybe is not necessary. Thank you very much in advance.

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• ZeroMQ REQ/REP on ipc:// and concurrency

  - by Metiu

  I implemented a JSON-RPC server using a REQ/REP 0MQ ipc:// socket and I'm experiencing strange behavior which I suspect is due to the fact that the ipc:// underlying unix socket is not a real socket, but rather a single pipe. From the documentation, one has to enforce strict zmq_send()/zmq_recv() alternation, otherwise the out-of-order zmq_send() will return an error. However, I expected the enforcement to be per-client, not per-socket. Of course with a Unix socket there is just one pipeline from multiple clients to the server, so the server won't know who it is talking with. Two clients could zmq_send() simultaneously and the server would see this as an alternation violation. The sequence could be: ClientA: zmq_send() ClientB: zmq_send() : will it block until the other send/receive completes? will it return -1? (I suspect it will with ipc:// due to inherent low-level problems, but with TCP it could distinguish the two clients) ClientA: zmq_recv() ClientB: zmq_recv() so what about tcp:// sockets? Will it work concurrently? Should I use some other locking mechanism to work around this?

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• .NET TCP Client/Server communication issue

  - by Jamie

  What I'm currently trying to do is make a very basic webchat for irc using silverlight. Basically how I'm trying to do it is have a tcp server listening for connections from silverlight. When a client connects it creates a new connection to irc and data is passed to/from the client/irc via the server application. I've gotten it to work fine for one client connection, but as soon as two (or more) clients connect multiple connections are made to irc but all data passed from the clients just goes through the latest irc connection (if that makes sense). For example Client1, Client2 and Client3 are all connected to irc, but no matter who sends data it all comes through Client3. Between the client and server app it recognizes the data coming in from different clients so i believe the problems lies within the way I've connected to the irc. When the TCP server accepts a new client a new thread is made to listen to incoming data, and from there a new thread is made to connect to irc. I'm sure thats where the problem exists, but I've confused myself a lot now and am wondering if anyone can help me figure out a solution. EDIT: What I think is the problem, is that it can't distinguish which thread the specific client is using, so it just sends it via the latest one. Can this even be done?

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• PHP: how to access variables inside a function that have been declared outside of it?

  - by Chris

  Please, I am very new and have not been confronted with OOP and all this related stuff, which I guess may be related to this issue (public, private, ...). So, any help and suggestions are very appreciated! :) At the very beginning of each page I include a file that starts the SESSION etc, lets call it session.php. In this file session.php, I include a file that contains a function, let's call it function1.php, because I need the function to be available in session.php. However, later in the main page I also include function2.php which needs to access variables set in session.php, so I additionally tried to include session.php in function2.php. The problem is that an error occurs as function1 will be declared multiple times... Fatal error: Cannot redeclare function1() (previously declared in ... So, what would be a more elegant and clean(er) solution for this? How could you solve it? Basically, I'd need to access variables inside a function that have been included in the main page before... Thank you very much in advance!

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• Grails - Removing an item from a hasMany association List on data bind?

  - by ecrane

  Grails offers the ability to automatically create and bind domain objects to a hasMany List, as described in the grails user guide. So, for example, if my domain object "Author" has a List of many "Book" objects, I could create and bind these using the following markup (from the user guide): <g:textField name="books[0].title" value="the Stand" /> <g:textField name="books[1].title" value="the Shining" /> <g:textField name="books[2].title" value="Red Madder" /> In this case, if any of the books specified don't already exist, Grails will create them and set their titles appropriately. If there are already books in the specified indices, their titles will be updated and they will be saved. My question is: is there some easy way to tell Grails to remove one of those books from the 'books' association on data bind? The most obvious way to do this would be to omit the form element that corresponds to the domain instance you want to delete; unfortunately, this does not work, as per the user guide: Then Grails will automatically create a new instance for you at the defined position. If you "skipped" a few elements in the middle ... Then Grails will automatically create instances in between. I realize that a specific solution could be engineered as part of a command object, or as part of a particular controller- however, the need for this functionality appears repeatedly throughout my application, across multiple domain objects and for associations of many different types of objects. A general solution, therefore, would be ideal. Does anyone know if there is something like this included in Grails?

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• PHP question about global variables and form requests

  - by user220201

  Hi, This is probably a stupid question but will ask anyway sine I have no idea. I have written basic php code which serve forms. Say I have a login page and I serve it using the login.php page and it will be called in the login.html page like this - <form action="login.php" method="post"> By this it is also implied that every POST needs its own php file, doesn't it? This kind of feels weird. Is there a way to have a single file, say code.php, and just have each of the forms as functions instead? EDIT: Specifically, say I have 5 forms that are used one after the other in my application. Say after login the user does A, B, C and D tasks each of which are sent to the server as a POST request. So instead of having A.php, B.php, C.php and D.php I would like to have a single code.php and have A(), B(), C() and D() as functions. Is there a way to do this? Also on the same note, how do I deal with say a global array (e.g. an array of currently logged in users) across multiple forms? I want to do this without writing to a DB. I know its probably better to write to a DB and query but is it even possible to do it with a global array? The reason I was thinking about having all the form functions in one file is to use a global array. Thanks, - Pav

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