Search Results

Search found 14799 results on 592 pages for 'instance eval'.

Page 479/592 | < Previous Page | 475 476 477 478 479 480 481 482 483 484 485 486  | Next Page >

• Avoiding Duplicate Data in DB (for use with Rails)

  - by ants

  I have five tables that I am trying to get to work nicely together but may need some help. I have three main tables: accounts members and roles. With two join tables account_members and account_member_roles. The accounts and members table are joined by account_members (fk account_id and member_id) table. The other 2 tables are the problem (roles and account_member_roles). A member of an account can have more than one role and I have the account_member_roles (fk account_member_id and role_id) table joining the account_members join table and the roles table. That seems logical but can you have a relationship with a join table? What I'd like to be able to do is when creaeting an account, for instance, I would like @account.save to include the roles and update the account_member_roles table neatly ..... but through the account_members join table. I've tried ..... accept_nested_attributes_for :members, :account_member_roles in the account.rb but I get ..... ActiveRecord::HasManyThroughCantAssociateThroughHasManyReflection (Cannot modify association 'Account#account_member_roles' because the source reflection class 'AccountMemberRole' is associated to 'AccountMember' via :has_many.) upon trying to save a record. Any advice on how I should approach this? CIA -ants

  Read the article

• Repeatedly execute a stored procedure

  - by manivineet

  I have a situation where I need to repeatedly execute a stored procedure Now this procedure (spMAIN) has a cursor inside which looks for a value from a table as T1,which has the following structure ID Status ---- -------- 1 New 2 New 3 success 4 Error now the cursor looks for all rows with a status of 'New' Now while processing , if that instance of the cursor encounters an error, another SP say spError needs to be called, the 'Status' column in T1 needs to be updated to 'Error' and spMAIN needs to be called again which again repeats the process, looking for rows with 'new' how do I do it? Also, also, while we are at it, what if an SP has other SPs inside it and if any of those SP raises an error, same thing needs to be done, the T1 table needs to be updated ('Error') and spMAIN needs to be called again. can you also recommend something ? here's some code ALTER PROC zzSpMain AS BEGIN DECLARE @id INT BEGIN TRY IF EXISTS ( SELECT * FROM dbo.zzTest WHERE istatus = 'new' ) BEGIN DECLARE c CURSOR FOR SELECT id FROM zztest WHERE istatus = 'new' OPEN c FETCH NEXT FROM c INTO @id WHILE @@FETCH_STATUS = 0 BEGIN PRINT @id IF @id = 2 BEGIN UPDATE zztest SET istatus = 'error' WHERE id = @id RAISERROR ( 'Error occured', 16, 1 ) END UPDATE zztest SET istatus = 'processed' WHERE id = @id FETCH NEXT FROM c INTO @id END CLOSE c DEALLOCATE c END END TRY begin CATCH EXEC zzSpError END CATCH END

  Read the article

• Can a standalone ruby script (windows and mac) reload and restart itself?

  - by user30997

  I have a master-workers architecture where the number of workers is growing on a weekly basis. I can no longer be expected to ssh or remote console into each machine to kill the worker, do a source control sync, and restart. I would like to be able to have the master place a message out on the network that tells each machine to sync and restart. That's where I hit a roadblock. If I were using any sane platform, I could just do: exec('ruby', __FILE__) ...and be done. However, I did the following test: p Process.pid sleep 1 exec('ruby', __FILE__) ...and on Windows, I get one ruby instance for each call to exec. None of them die until I hit ^C on the window in question. On every platform I tried this on, it is executing the new version of the file each time, which I have verified this by making simple edits to the test script while the test marched along. The reason I'm printing the pid is to double-check the behavior I'm seeing. On windows, I am getting a different pid with each execution - which I would expect, considering that I am seeing a new process in the task manager for each run. The mac is behaving correctly: the pid is the same for every system call and I have verified with dtrace that each run is trigging a call to the execve syscall. So, in short, is there a way to get a windows ruby script to restart its execution so it will be running any code - including itself - that has changed during its execution? Please note that this is not a rails application, though it does use activerecord.

  Read the article

• ASP.NET MVC UpdateModel doesn't update inherited public properties??

  - by mrjoltcola

  I refactored some common properties into a base class and immediately my model updates started failing. UpdateModel() and TryUpdateModel() do not seem to update inherited public properties. I cannot find detailed info on MSDN nor Google as to the rules or semantics of these methods. The docs are terse (http://msdn.microsoft.com/en-us/library/dd470933.aspx), simply stating: Updates the specified model instance using values from the controller's current value provider. Well that leads us to believe it is as simple as that. It makes no mention of limitations with inheritance. My assumption is the methods are reflecting on the top class only, ignoring base properties, but this seems to be an ugly shortcoming, if so. SOLVED: Eep, this turned out to have nothing to do with inheritance. My base class was implemented with public fields, not properties. Switching them to formal properties (adding {get; set; }) was all I needed. This has bitten me before, I keep wanting to use simple, public fields.

  Read the article

• Java method keyword "final" and its use

  - by Lukas Eder

  When I create complex type hierarchies (several levels, several types per level), I like to use the final keyword on methods implementing some interface declaration. An example: interface Garble { int zork(); } interface Gnarf extends Garble { /** * This is the same as calling {@link #zblah(0)} */ int zblah(); int zblah(int defaultZblah); } And then abstract class AbstractGarble implements Garble { @Override public final int zork() { ... } } abstract class AbstractGnarf extends AbstractGarble implements Gnarf { // Here I absolutely want to fix the default behaviour of zblah // No Gnarf shouldn't be allowed to set 1 as the default, for instance @Override public final int zblah() { return zblah(0); } // This method is not implemented here, but in a subclass @Override public abstract int zblah(int defaultZblah); } I do this for several reasons: It helps me develop the type hierarchy. When I add a class to the hierarchy, it is very clear, what methods I have to implement, and what methods I may not override (in case I forgot the details about the hierarchy) I think overriding concrete stuff is bad according to design principles and patterns, such as the template method pattern. I don't want other developers or my users do it. So the final keyword works perfectly for me. My question is: Why is it used so rarely in the wild? Can you show me some examples / reasons where final (in a similar case to mine) would be very bad?

  Read the article

• Change select's class based on selected option's class

  - by Alasdair

  I have a page that contains numerous <select> elements. What I'm trying to achieve is to ensure that if a <select>'s selected <option> has a class called italic, then the <select> then has the italic class added (i.e. jQuery.addClass('italic')). If it doesn't, then the italic class is removed from the <select> to ensure other <option> elements are displayed correctly (i.e. jQuery.removeClass('italic')). What I'm noticing with most of my attempts is that either all the <select> have the italic class or that the italic class isn't being removed accordingly. Since I'm unsure my choice in selectors and callback logic are particularly sound or good practice in this instance (as I've been frustratingly trying to make it work) I've decided not to include the code I used in previous attempts. Instead, refer to this small HTML & CSS example: .italic { font-style: italic; } <select id="foo" name="foo" size="1" <option value="NA" selected="selected" - Select - </option <option value="1"Bar</option <option value="2"Fu</option <option value="3"Baz</option </select Also, I am aware that not all browsers support CSS styling of <select> and <option>. The related J2EE web application will only ever be accessed via Firefox under a controlled environment.

  Read the article

• Does isEmpty method in Stream evaluate the whole Stream?

  - by abhin4v

  In Scala, does calling isEmtpy method on an instance of Stream class cause the stream to be evaluated completely? My code is like this: import Stream.cons private val odds: Stream[Int] = cons(3, odds.map(_ + 2)) private val primes: Stream[Int] = cons(2, odds filter isPrime) private def isPrime(n: Int): Boolean = n match { case 1 => false case 2 => true case 3 => true case 5 => true case 7 => true case x if n % 3 == 0 => false case x if n % 5 == 0 => false case x if n % 7 == 0 => false case x if (x + 1) % 6 == 0 || (x - 1) % 6 == 0 => true case x => primeDivisors(x) isEmpty } import Math.{sqrt, ceil} private def primeDivisors(n: Int) = primes takeWhile { _ <= ceil(sqrt(n))} filter {n % _ == 0 } So, does the call to isEmpty on the line case x => primeDivisors(x) isEmpty cause all the prime divisors to be evaluated or only the first one?

  Read the article

• jQuery inconsistent .remove by class on element with multiple classes

  - by pedalpete

  I've got a page where messages and associated elements (responses, forwards, etc) all share a class based on the database id of the parent. For example this is a message this is another message this is a comment this is another comment tim posted a new message sara forwarded a message to john at times I need to remove all elements with the same id, so I originally had jQuery('div#'+id).remove(); but that would sometimes not remove all the ids because ids are supposed to be unique. So I added the id as a class. now I use jQuery('div.'+id).remove(); but this seems to be about 80% effective, and sometimes the divs aren't being removed. I'm not sure if the issue is because the div has more than one class, but I need the classes because that is how I refer to the elements when somebody clicks. For instance, jQuery('div.message').click(function(){ get the id, send it to the server and get the message }); is there something wrong I'm doing here? or is there a better way to do this?

  Read the article

• How to work threading with ConcurrentQueue<T>.

  - by dboarman

  I am trying to figure out what the best way of working with a queue will be. I have a process that returns a DataTable. Each DataTable, in turn, is merged with the previous DataTable. There is one problem, too many records to hold until the final BulkCopy (OutOfMemory). So, I have determined that I should process each incoming DataTable immediately. Thinking about the ConcurrentQueue<T>...but I don't see how the WriteQueuedData() method would know to dequeue a table and write it to the database. For instance: public class TableTransporter { private ConcurrentQueue<DataTable> tableQueue = new ConcurrentQueue<DataTable>(); public TableTransporter() { tableQueue.OnItemQueued += new EventHandler(WriteQueuedData); // no events available } public void ExtractData() { DataTable table; // perform data extraction tableQueue.Enqueue(table); } private void WriteQueuedData(object sender, EventArgs e) { BulkCopy(e.Table); } } My first question is, aside from the fact that I don't actually have any events to subscribe to, if I call ExtractData() asynchronously will this be all that I need? Second, is there something I'm missing about the way ConcurrentQueue<T> functions and needing some form of trigger to work asynchronously with the queued objects?

  Read the article

• WPF DataBinding to standard CLR properties in code-behind

  - by nukefusion

  Hi everyone, Just learning WPF databinding and have a gap in my understanding. I've seen a few similar questions on StackOverflow, but I'm still struggling in determining what I have done wrong. I have a simple Person class with a Firstname and Surname property (standard CLR properties). I also have a standard CLR property on my Window class that exposes an instance of Person. I've then got some XAML, with two methods of binding. The first works, the second doesn't. Can anybody help me to understand why the second method fails? There's no binding error message in the Output log. <Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:WpfApplication1" Title="Window1" Height="300" Width="300" DataContext="{Binding RelativeSource={RelativeSource Self}, Path=MyPerson}"> <StackPanel> <Label>My Person</Label> <WrapPanel> <Label>First Name:</Label> <Label Content="{Binding RelativeSource={RelativeSource AncestorType=Window, Mode=FindAncestor}, Path=MyPerson.FirstName}"></Label> </WrapPanel> <WrapPanel> <Label>Last Name:</Label> <Label Content="{Binding MyPerson.Surname}"></Label> </WrapPanel> </StackPanel> Edit: Ok, thanks so far. I've changed the second expression to: <Label Content="{Binding Surname}"></Label> I still can't get it to work though!

  Read the article

• What is optimal hardware configuration for heavy load LAMP application

  - by Piotr Kochanski

  I need to run Linux-Apache-PHP-MySQL application (Moodle e-learning platform) for a large number of concurrent users - I am aiming 5000 users. By concurrent I mean that 5000 people should be able to work with the application at the same time. "Work" means not only do database reads but writes as well. The application is not very typical, since it is doing a lot of inserts/updates on the database, so caching techniques are not helping to much. We are using InnoDB storage engine. In addition application is not written with performance in mind. For instance one Apache thread usually occupies about 30-50 MB of RAM. I would be greatful for information what hardware is needed to build scalable configuration that is able to handle this kind of load. We are using right now two HP DLG 380 with two 4 core processors which are able to handle much lower load (typically 300-500 concurrent users). Is it reasonable to invest in this kind of boxes and build cluster using them or is it better to go with some more high-end hardware? I am particularly curious how many and how powerful servers are needed (number of processors/cores, size of RAM) what network equipment should be used (what kind of switches, network cards) any other hardware, like particular disc storage solutions, etc, that are needed Another thing is how to put together everything, that is what is the most optimal architecture. Clustering with MySQL is rather hard (people are complaining about MySQL Cluster, even here on Stackoverflow).

  Read the article

• Using bitwise operators on > 32 bit integers

  - by dqhendricks

  I am using bitwise operations in order to represent many access control flags within one integer. ADMIN_ACCESS = 1; EDIT_ACCOUNT_ACCESS = 2; EDIT_ORDER_ACCESS = 4; var myAccess = 3; // ie: ( ADMIN_ACCESS | EDIT_ACCOUNT_ACCESS ) if ( myAccess & EDIT_ACCOUNT_ACCESS ) { // check for correct access // allow for editing of account } Most of this is occurring on the PHP side of my project. There is one piece however where Javascript is used to join several access flags using | when saving someone's access level. This works fine to a point. I have found that once an integer (flag) gets too large ( 32bit), it no longer works correctly with bitwise operators in Javascript. For instance: alert( 4294967296 | 1 ); // equals 1, but should equal 4294967297 I am trying to find a workaround for this so that I do not have to limit my number of access control flags to 32. Each access control flag is two times the previous control flag so that each control flag will not interfere with other control flags. dec(4) = bin(100) dec(8) = bin(1000) dec(16) = bin(10000) I have noticed that when adding two of these flags together with a simple +, it seems to come out with the same answer as a bitwise or operation, but am having trouble wrapping my head around whether this is a simple substitution, or if there might be problems with doing this. Can anyone comment on the validity of this workaround? Example: (4294967296 | 262144 | 524288) == (4294967296 + 262144 + 524288)

  Read the article

• FLV performance and garbage collection

  - by justinbach

  I'm building a large flash site (AS3) that uses huge FLVs as transition videos from section to section. The FLVs are 1280x800 and are being scaled to 1680x1050 (much of which is not displayed to users with smaller screens), and are around 5-8 seconds apiece. I'm encoding the videos using On2's hi-def codec, VP6-S, and playback is pretty good with native FLV players, Perian-equipped Quicktime, and simple proof-of-concept FLV playback apps built in AS3. The problem I'm having is that in the context of the actual site, playback isn't as smooth; the framerate isn't quite as good as it should be, and more problematically, there's occasional jerkiness and dropped frames (sometimes pausing the video for as long as a quarter of a second or so). My guess is that this is being caused by garbage collection in the Flash player, which happens nondeterministically and is therefore hard to test and control for. I'm using a single instance of FLVPlayback to play the videos; I originally was using NetStream objects and so forth directly but switched to FLVPlayback for this reason. Has anyone experienced this sort of jerkiness with FLVPlayback (or more generally, with hi-def Flash video)? Am I right about GC being the culprit here, and if so, is there any way to prevent it during playback of these system-intensive transitions?

  Read the article

• VEMap and a GeoRSS feed(hosted separately)

  - by Alexis Abril

  The scenario is as follows: A WCF web service exists that outputs a valid GeoRSS feed. This lives in its own domain as a number of different applications have access to it. A web page(on a different site) has been created with an instance of a VEMap(Bing/Virtual Earth map object). Now, VEMap can accept an input feed in this format via the following: var layer = new VEShapeLayer(); var veLayerSpec = new VEShapeSourceSpecification(VEDataType.GeoRSS, "someurl", layer); map.ImportShapeLayerData(veLayerSpec, onComplete, true); onComplete is a callback function I'm using to replace the default pin graphic with something custom. The question is in regards to "someurl", which is a path to a local xml file containing the geographic information(georss simple format). I've realized this feed and the map must be hosted in the same domain, so I've created a generic handler that reads the remote feed and returns it in the same format. var veLayerSpec = new VEShapeSourceSpecification(VEDataType.GeoRSS, "/somelocalhandler.ashx", layer); When I do this, I get the VEMap error("z is null"). This is the same error one would receive when trying to access a remote feed. When I copy the feed into a local xml file(ie, "feed.xml") there is no error. The order of operations is currently: remote feed - local handler - VEMap import If I'm over complicating this procedure, let me know! I'm a bit new to the Bing Maps API and might have missed something. Any assistance is appreciated.

  Read the article

• Efficient method to calculate the rank vector of a list in Python

  - by Tamás

  I'm looking for an efficient way to calculate the rank vector of a list in Python, similar to R's rank function. In a simple list with no ties between the elements, element i of the rank vector of a list l should be x if and only if l[i] is the x-th element in the sorted list. This is simple so far, the following code snippet does the trick: def rank_simple(vector): return [rank for rank in sorted(range(n), key=vector.__getitem__)] Things get complicated, however, if the original list has ties (i.e. multiple elements with the same value). In that case, all the elements having the same value should have the same rank, which is the average of their ranks obtained using the naive method above. So, for instance, if I have [1, 2, 3, 3, 3, 4, 5], the naive ranking gives me [0, 1, 2, 3, 4, 5, 6], but what I would like to have is [0, 1, 3, 3, 3, 5, 6]. Which one would be the most efficient way to do this in Python? Footnote: I don't know if NumPy already has a method to achieve this or not; if it does, please let me know, but I would be interested in a pure Python solution anyway as I'm developing a tool which should work without NumPy as well.

  Read the article

• Action Filter Dependency Injection in ASP.NET MVC 3 RC2 with StructureMap

  - by Ben

  Hi, I've been playing with the DI support in ASP.NET MVC RC2. I have implemented session per request for NHibernate and need to inject ISession into my "Unit of work" action filter. If I reference the StructureMap container directly (ObjectFactory.GetInstance) or use DependencyResolver to get my session instance, everything works fine: ISession Session { get { return DependencyResolver.Current.GetService<ISession>(); } } However if I attempt to use my StructureMap filter provider (inherits FilterAttributeFilterProvider) I have problems with committing the NHibernate transaction at the end of the request. It is as if ISession objects are being shared between requests. I am seeing this frequently as all my images are loaded via an MVC controller so I get 20 or so NHibernate sessions created on a normal page load. I added the following to my action filter: ISession Session { get { return DependencyResolver.Current.GetService<ISession>(); } } public ISession SessionTest { get; set; } public override void OnResultExecuted(System.Web.Mvc.ResultExecutedContext filterContext) { bool sessionsMatch = (this.Session == this.SessionTest); SessionTest is injected using the StructureMap Filter provider. I found that on a page with 20 images, "sessionsMatch" was false for 2-3 of the requests. My StructureMap configuration for session management is as follows: For<ISessionFactory>().Singleton().Use(new NHibernateSessionFactory().GetSessionFactory()); For<ISession>().HttpContextScoped().Use(ctx => ctx.GetInstance<ISessionFactory>().OpenSession()); In global.asax I call the following at the end of each request: public Global() { EndRequest += (sender, e) => { ObjectFactory.ReleaseAndDisposeAllHttpScopedObjects(); }; } Is this configuration thread safe? Previously I was injecting dependencies into the same filter using a custom IActionInvoker. This worked fine until MVC 3 RC2 when I started experiencing the problem above, which is why I thought I would try using a filter provider instead. Any help would be appreciated Ben P.S. I'm using NHibernate 3 RC and the latest version of StructureMap

  Read the article

• ASP.NET MVC View ReRenders Part of Itself

  - by Jason

  In all my years of .NET programming I have not run across a bug as weird as this one. I discovered the problem because some elements on the page were getting double-bound by jQuery. After some (ridiculous) debugging, I finally discovered that once the view is completely done rendering itself and all its children partial views, it goes back to an arbitrary yet consistent location and re-renders itself. I have been pulling my hair out about this for two days now and I simply cannot get it to render itself only once! For lack of any better debugging idea, I've painstakingly added logging tracers throughout the HTML just so I can pin down what may be causing this. For instance, this code ($log just logs to the console): ... <script type="text/javascript">var x = 0; $log('1');</script> <div id="new-ad-form"> <script type="text/javascript">x++;$log('1.5', x);</script> ... will yield ... <--- this happens before this snippet 1 1.5 1 ... 10 <--- bottom of my form, after snippet 1.5 2 <--- beginning of part that runs again! ... 9 <--- this happens after this snippet I've searched my codebase high and low, but there is NOTHING that says that it should re-render part of a page. I'm wondering if the jQueryUI has anything to do with it, as #new-ad-form is the container for a jQueryUI dialog box. If this is potentially the case, here's my init code for that: $('#new-ad-form').dialog({ autoOpen: false, modal: true, width: 470, title: 'Create A New Ad', position: ['center', 35], close: AdEditor.reset });

  Read the article

• In .NET when Aborting Thread, can this piece of code get corrupted?

  - by bosko

  Little intro: In complex multithreaded aplication (enterprise service bus EBS), I need to use Thread.Abort, because this EBS accepts user written modules which communicates with hardware security modules. So if this module gets deadlocked or hardware stops responding - i need to just unload this module and rest of this server aplication must keep runnnig. So there is abort sync mechanism which ensures that code can be aborted only in user section and this section must be marked as AbortAble. If this happen there is possibility that ThreadAbortException will be thrown in this pieace of code: public void StopAbortSection() { var id = Thread.CurrentThread.ManagedThreadId; lock (threadIdMap[id]) { .... } } If module is on AbortSection and Aplication decides to abort module, but after this decision but before actual Thread.Abort, module enters NonAbortableSection by calling this method, but lock is actualy taken on that locking object. So lock will block until Abort or abort can be executed before reaching this block by this code. But Object with this method is essential and i need to be sure that this pieace of code is safe to abort in any moment. Probably i have to mention that threadIdMap is Dictionary(int,ManualResetEvent), so locking object is instance of ManualResetEvent. I hope you now understad my question. Sorry for its largeness.

  Read the article

• Error with Property Validation in Form Submission in ASP.NET MVC

  - by Maxim Z.

  I have a simple form on an ASP.NET MVC site that I'm building. This form is submitted, and then I validate that the form fields aren't null, empty, or improperly formatted. However, when I use ModelState.AddModelError() to indicate validation errors from my controller code, I get an error when my view is re-rendered. In Visual Studio, I get that the following line is highlighted as being the location of the error: <%=Html.TextBox("Email")%> The error is the following: NullReferenceException was unhandled by user code - object reference not set to an instance of an object. My complete code for that textbox is the following: <p> <label for="Email">Your Email:</label> <%=Html.TextBox("Email")%> <%=Html.ValidationMessage("Email", "*") %> </p> Here's how I'm doing that validation in my controller: try { System.Net.Mail.MailAddress address = new System.Net.Mail.MailAddress(email); } catch { ModelState.AddModelError("Email", "Should not be empty or invalid"); } return View(); Note: this applies to all of my fields, not just my Email field, as long as they are invalid.

  Read the article

• How to remove a status message added by the seam security module?

  - by Joshua

  I would like to show a different status message, when a suspended user tries to login. If the user is active we return true from the authenticate method, if not we add a custom StatusMessage message mentioning that the "User X has been suspended". The underlying Identity authentication also fails and adds a StatusMessage. I tried removing the seam generated statusMessage with the following methods, but it doesn't seem to work and shows me 2 different status messages (my custom message, seam generated). What would be the issue here? StatusMessages statusMessages; statusMessages.clear() statusMessages.clearGlobalMessages() statusMessages.clearKeyedMessages(id) EDIT1: public boolean authenticate() { log.info("Authenticating {0}", identity.getCredentials().getUsername()); String username = identity.getCredentials().getUsername(); String password = identity.getCredentials().getPassword(); // return true if the authentication was // successful, false otherwise try { Query query = entityManager.createNamedQuery("user.by.login.id"); query.setParameter("loginId", username); // only active users can log in query.setParameter("status", "ACTIVE"); currentUser = (User)query.getSingleResult(); } catch (PersistenceException ignore) { // Provide a status message for the locked account statusMessages.clearGlobalMessages(); statusMessages.addFromResourceBundle( "login.account.locked", new Object[] { username }); return false; } IdentityManager identityManager = IdentityManager.instance(); if (!identityManager.authenticate(username, "password")) { return false; } else { log.info("Authenticated user {0} successfully", username); } }

  Read the article

• Setting nested object to null when selected option has empty value

  - by Javi

  Hello, I have a Class which models a User and another which models his country. Something like this: public class User{ private Country country; //other attributes and getter/setters } public class Country{ private Integer id; private String name; //other attributes and getter/setters } I have a Spring form where I have a combobox so the user can select his country or can select the undefined option to indicate he doen't want to provide this information. So I have something like this: <form:select path="country"> <form:option value="">-Select one-</form:option> <form:options items="${countries}" itemLabel="name" itemValue="id"/> </form:select> In my controller I get the autopopulated object with the user information and I want to have country set to null when the "-Select one-" option has been selected. So I have set a initBinder with a custom editor like this: @InitBinder protected void initBinder(WebDataBinder binder) throws ServletException { binder.registerCustomEditor(Country.class, "country", new CustomCountryEditor()); } and my editor do something like this: public class CustomCountryEditor(){ @Override public String getAsText() { //I return the Id of the country } @Override public void setAsText(String str) { //I search in the database for a country with id = new Integer(str) //and set country to that value //or I set country to null in case str == null } } When I submit the form it works because when I have country set to null when I have selected "-Select one-" option or the instance of the country selected. The problem is that when I load the form I have a method like the following one to load the user information. @ModelAttribute("user") public User getUser(){ //loads user from database } The object I get from getUser() has country set to a specific country (not a null value), but in the combobox is not selected any option. I've debugged the application and the CustomCountryEditor works good when setting and getting the text, thoughgetAsText method is called for every item in the list "countries" not only for the "country" field. Any idea? Is there a better way to set null the country object when I select no country option in the combobox? Thanks

  Read the article

• Copy vector of values to vector of pairs in one line

  - by Kirill V. Lyadvinsky

  I have the following types: struct X { int x; X( int val ) : x(val) {} }; struct X2 { int x2; X2() : x2() {} }; typedef std::pair<X, X2> pair_t; typedef std::vector<pair_t> pairs_vec_t; typedef std::vector<X> X_vec_t; I need to initialize instance of pairs_vec_t with values from X_vec_t. I use the following code and it works as expected: int main() { pairs_vec_t ps; X_vec_t xs; // this is not empty in the production code ps.reserve( xs.size() ); { // I want to change this block to one line code. struct get_pair { pair_t operator()( const X& value ) { return std::make_pair( value, X2() ); } }; std::transform( xs.begin(), xs.end(), back_inserter(ps), get_pair() ); } return 0; } What I'm trying to do is to reduce my copying block to one line with using boost::bind. This code is not working: for_each( xs.begin(), xs.end(), boost::bind( &pairs_vec_t::push_back, ps, boost::bind( &std::make_pair, _1, X2() ) ) ); I know why it is not working, but I want to know how to make it working without declaring extra functions and structs?

  Read the article

• Error handling in PHP

  - by Industrial

  Hi guys, We're building a PHP app based on Good old MVC (codeigniter framework) and have run into trouble with a massive chained action that consists of multiple model calls, that together is a part of a big transaction to the database. We want to be able to do a list of actions and get a status report of each one back from the function, whatever the outcome is. Our first initial idea was to utilize the exceptions of PHP5, but since we want to also need status messages that doesnt break the execution of the script, this was our solution that we came up with. It goes a little something like this: $sku = $this->addSku( $name ); if ($sku === false) { $status[] = 'Something gone terrible wrong'; $this->db->trans_rollback(); return $status; } $image= $this->addImage( $filename); if ($image=== false) { $error[] = 'Image could not be uploaded, check filesize'; $this->db->trans_rollback(); return $status; } Our controller looks like this: $var = $this->products->addProductGroup($array); if (is_array($var)) { foreach ($var as $error) { echo $error . '<br />'; } } It appears to be a very fragile solution to do what we need, but it's neither scalable, neither effective when compared to pure PHP exceptions for instance. Is this really the way that this kind of stuff generally is handled in MVC based apps? Thanks!

  Read the article

• Improve Application Performace

  - by Gtest

  Hello, Want To Improvide Performace Of C#.Net Applicaiton.. In My Application I am using Third Party Interop/Dll To Process .doc Files. It's a Simple Operation, Which Pass Input/Output FilePath to Interop dll ...& dll will execute text form input file. To Improve Performace I have Tried, Execute 2 therad to process 32 files.(each Thread process 16 files) Execute application code by creating 2 new AppDomains(each AppDomain Code process 16 files) Execute Code Using TPL(Task Parellel Library) But all options take around same time (32 sec) to process 32 files.Manually process tooks same 32 sec to process 32 files. Just tried one thing ..when i have created sample exe to process 16 files as input & output for refrence PAth given in TextBox. ..I open 2 exe instance to process. 1 exe has differnt 16 input files & output Created with input file path 2 exe has differnt 16 input files & output Created with input file path When i click on start button of both exe ..it use 100% cpu & Utilize both core significantly & Process Completed within 16 sec for 32 files. Can we provide this kind of explicit prallism to Improve my applicaiton Peformace? Thanks.

  Read the article

• How do you read a file line by line in your language of choice?

  - by Jon Ericson

  I got inspired to try out Haskell again based on a recent answer. My big block is that reading a file line by line (a task made simple in languages such as Perl) seems complicated in a functional language. How do you read a file line by line in your favorite language? So that we are comparing apples to other types of apples, please write a program that numbers the lines of the input file. So if your input is: Line the first. Next line. End of communication. The output would look like: 1 Line the first. 2 Next line. 3 End of communication. I will post my Haskell program as an example. Ken commented that this question does not specify how errors should be handled. I'm not overly concerned about it because: Most answers did the obvious thing and read from stdin and wrote to stdout. The nice thing is that it puts the onus on the user to redirect those streams the way they want. So if stdin is redirected from a non-existent file, the shell will take care of reporting the error, for instance. The question is more aimed at how a language does IO than how it handles exceptions. But if necessary error handling is missing in an answer, feel free to either edit the code to fix it or make a note in the comments.

  Read the article

< Previous Page | 475 476 477 478 479 480 481 482 483 484 485 486  | Next Page >