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  • How to Bind a Command in WPF

    - by MegaMind
    Sometimes we used complex ways so many times, we forgot the simplest ways to do the task. I know how to do command binding, but i always use same approach. Create a class that implements ICommand interface and from the view model i create new instance of that class and binding works like a charm. This is the code that i used for command binding public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); DataContext = this; testCommand = new MeCommand(processor); } ICommand testCommand; public ICommand test { get { return testCommand; } } public void processor() { MessageBox.Show("hello world"); } } public class MeCommand : ICommand { public delegate void ExecuteMethod(); private ExecuteMethod meth; public MeCommand(ExecuteMethod exec) { meth = exec; } public bool CanExecute(object parameter) { return false; } public event EventHandler CanExecuteChanged; public void Execute(object parameter) { meth(); } } But i want to know the basic way to do this, no third party dll no new class creation. Do this simple command binding using a single class. Actual class implements from ICommand interface and do the work.

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  • WPF validation on Enter Key Up

    - by Martin
    I'm trying to validate a UI change when Enter key is pressed. The UI element is a textbox, which is data binded to a string. My problem is that the data binding hasn't updated TestText when Enter key is Up. It is only updated when I press the button which brings up a message box. /// <summary> /// Interaction logic for Window1.xaml /// </summary> public partial class Window1 : Window, INotifyPropertyChanged { String _testText = new StringBuilder("One").ToString(); public string TestText { get { return _testText; } set { if (value != _testText) { _testText = value; OnPropertyChanged("TestText"); } } } public Window1() { InitializeComponent(); myGrid.DataContext = this; } private void OnPropertyChanged(string property) { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(property)); } } public event PropertyChangedEventHandler PropertyChanged; private void onKeyUp(object sender, KeyEventArgs e) { if (e.Key != System.Windows.Input.Key.Enter) return; System.Diagnostics.Trace.WriteLine(TestText); } private void button1_Click(object sender, RoutedEventArgs e) { MessageBox.Show(TestText); } } Window XAML: Window x:Class="VerificationTest.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="300" Width="300" KeyUp="onKeyUp" TextBox XAML: TextBox Name="myTextBox" Text="{Binding TestText}" Button XAML: Button Name="button1" Click="button1_Click"

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  • How to programmatically create a node in Drupal 8?

    - by chapka
    I'm designing a new module in Drupal 8. It's a long-term project that won't be going public for a few months at least, so I'm using it as a way to figure out what's new. In this module, I want to be able to programmatically create nodes. In Drupal 7, I would do this by creating the object, then calling "node_submit" and "node_save". These functions no longer exist in Drupal 8. Instead, according to the documentation, "Modules and scripts may programmatically submit nodes using the usual form API pattern." I'm at a loss. What does this mean? I've used Form API to create forms in Drupal 7, but I don't get what the docs are saying here. What I'm looking to do is programmatically create at least one and possibly multiple new nodes, based on information not taken directly from a user-presented form. I need to be able to: 1) Specify the content type 2) Specify the URL path 3) Set any other necessary variables that would previously have been handled by the now-obsolete node_object_prepare() 4) Commit the new node object I would prefer to be able to do this in an independent, highly abstracted function not tied to a specific block or form. So what am I missing?

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  • Flash: Closest point to MovieClip

    - by LiraNuna
    I need to constrain a point inside a DisplayObject given to me by the artist. I got it working but only for the occations where the cursor is still inside bounds. The limited object is called limited. function onSqMouseMove(event:MouseEvent) { if(bounds.hitTestPoint(event.stageX, event.stageY, true)) { limited.x = event.stageX; limited.y = event.stageY; } else { /* Find closest point in the Sprite */ } } limited.addEventListener(MouseEvent.MOUSE_DOWN, function(event:MouseEvent) { stage.addEventListener(MouseEvent.MOUSE_MOVE, onSqMouseMove); }); limited.addEventListener(MouseEvent.MOUSE_UP, function(event:MouseEvent) { stage.removeEventListener(MouseEvent.MOUSE_MOVE, onSqMouseMove); }); How do I go about implementing the other half of the function? I am aware Sprite's startDrag accepts arguments, where the second one is the constraint rectangle, but in my case, bounds are an arbitrary shape. When the object is dragged outside the bounds, I want to calculate the closest point from the cursor to bounds' polygon. Just to note that bounds can have 'holes'.

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  • Foreign key relationships in Entity Framework

    - by Anders Svensson
    I'm trying to add an object created from Entity Data Model classes. I have a table called Users, which has turned into a User EDM class. And I also have a table Pages, which has become a Page EDM class. These tables have a foreign key relationship, so that each page is associated with many users. Now I want to be able to add a page, but I can't get how to do it. I get a nullreference exception on Users below. I'm still rather confused by all this, so I'm sure it's a simple error, but I just can't see how to do it. Also, by the way, the compiler requires that I set PageID in the object initializer, even though this field is set to be an automatic id in the table. Am I doing it right just setting it to 0, expecting it to be updated automatically in the table when saved, or how should I do that? Any help appreciated! The method in question: private Page GetPage(User currentUser) { string url = _request.ServerVariables["url"].ToLower(); var userPages = from p in _context.PageSet where p.Users.UserID == currentUser.UserID select p; var existingPage = userPages.FirstOrDefault(e => e.Url == url); //Could be combined with above, but hard to read? if (existingPage != null) return existingPage; Page page = new Page() { Count = 0, Url = _request.ServerVariables["url"].ToLower(), PageID = 0, //Only initial value, changed later? }; _context.AddToPageSet(page); page.Users.UserID = currentUser.UserID; //Here's the problem... return page; }

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  • LINQ Joins - Performance

    - by Meiscooldude
    I am curious on how exactly LINQ (not LINQ to SQL) is performing is joins behind the scenes in relation to how Sql Server performs joins. Sql Server before executing a query, generates an Execution Plan. The Execution Plan is basically an Expression Tree on what it believes is the best way to execute the query. Each node provides information on whether to do a Sort, Scan, Select, Join, ect. On a 'Join' node in our execution plan, we can see three possible algorithms; Hash Join, Merge Join, and Nested Loops Join. Sql Server will choose which algorithm to for each Join operation based on expected number of rows in Inner and Outer tables, what type of join we are doing (some algorithms don't support all types of joins), whether we need data ordered, and probably many other factors. Join Algorithms: Nested Loop Join: Best for small inputs, can be optimized with ordered inner table. Merge Join: Best for medium to large inputs sorted inputs, or an output that needs to be ordered. Hash Join: Best for medium to large inputs, can be parallelized to scale linearly. LINQ Query: DataTable firstTable, secondTable; ... var rows = from firstRow in firstTable.AsEnumerable () join secondRow in secondTable.AsEnumerable () on firstRow.Field<object> (randomObject.Property) equals secondRow.Field<object> (randomObject.Property) select new {firstRow, secondRow}; SQL Query: SELECT * FROM firstTable fT INNER JOIN secondTable sT ON fT.Property = sT.Property Sql Server might use a Nested Loop Join if it knows there are a small number of rows from each table, a merge join if it knows one of the tables has an index, and Hash join if it knows there are a lot of rows on either table and neither has an index. Does Linq choose its algorithm for joins? or does it always use one?

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  • Compound Primary Key in Hibernate using Annotations

    - by Rich
    Hi, I have a table which uses two columns to represent its primary key, a transaction id and then the sequence number. I tried what was recommended http://docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/#entity-mapping in section 2.2.3.2.2, but when I used the Hibernate session to commit this Entity object, it leaves out the TXN_ID field in the insert statement and only includes the BA_SEQ field! What's going wrong? Here's the related code excerpt: @Id @Column(name="TXN_ID") private long txn_id; public long getTxnId(){return txn_id;} public void setTxnId(long t){this.txn_id=t;} @Id @Column(name="BA_SEQ") private int seq; public int getSeq(){return seq;} public void setSeq(int s){this.seq=s;} And here are some log statements to show what exactly happens to fail: In createKeepTxnId of DAO base class: about to commit Transaction :: txn_id->90625 seq->0 ...<Snip>... Hibernate: insert into TBL (BA_ACCT_TXN_ID, BA_AUTH_SRVC_TXN_ID, BILL_SRVC_ID, BA_BILL_SRVC_TXN_ID, BA_CAUSE_TXN_ID, BA_CHANNEL, CUSTOMER_ID, BA_MERCHANT_FREETEXT, MERCHANT_ID, MERCHANT_PARENT_ID, MERCHANT_ROOT_ID, BA_MERCHANT_TXN_ID, BA_PRICE, BA_PRICE_CRNCY, BA_PROP_REQS, BA_PROP_VALS, BA_REFERENCE, RESERVED_1, RESERVED_2, RESERVED_3, SRVC_PROD_ID, BA_STATUS, BA_TAX_NAME, BA_TAX_RATE, BA_TIMESTAMP, BA_SEQ) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?) [WARN] util.JDBCExceptionReporter SQL Error: 1400, SQLState: 23000 [ERROR] util.JDBCExceptionReporter ORA-01400: cannot insert NULL into ("SCHEMA"."TBL"."TXN_ID") The important thing to note is I print out the entity object which has a txn_id set, and then the following insert into statement does not include TXN_ID in the listing and thus the NOT NULL table constraint rejects the query.

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  • Fading in and fading out for a form

    - by karthik
    hi i have a requirement in which my form is transparent,if my mouse enters into it the form should became visible,if my mouse leaves out of the form it becomes transparent, i have three different controls placed in my form , each controls mouse leave and mouse enter is the same that of the form . if my mouse enters into the form and enters into a control form_mouseleaveevent and control_mouseenterd gets fired so iam not able to achieve it,how to overcome this. below is the piece of code for this: private void TransToOpac() { if (!isTransparent) return; if (TtoOON == false ) { TtoOON = true; for (i = this.Opacity; i <= 1; i = i + 0.02) { this.Opacity = i; Thread.Sleep(50); } isTransparent = false; TtoOON = false; } } private void OpacToTrans() { if (isTransparent) return; if (OtoTON == false ) { OtoTON = true; for (i = this.Opacity; i >= 0.5; i = i - 0.02) { this.Opacity = i; Thread.Sleep(50); } isTransparent = true; OtoTON = false; } } private void OnMouseEntered(object sender, EventArgs e) { TransToOpac(); } private void OnMouseLeft(object sender, EventArgs e) { OpacToTrans(); }

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  • Strange behaviour of CheckBox and TwoWay bound property

    - by walkor
    Hello, everyone. I fell in the following situation: I have a main UserControl with a DataGrid (which contains List). I need to show different panels depending on properties of the selected row(object). So i've created 2 controls and included them into this main control. Main control has 2 public properties - public List<ComplexObject> SourceList { get; set; } and public ComplexObject CurrentObject { get; set; } Pseudo-code: <UserControl x:Name="Main"> <DataGrid ItemsSource="{Binding SourceList}" SelectedItem="{Binding CurrentObject, Mode=TwoWay}"/> <Controls:RightPanelFirst Visibility="condition2"/> <Controls:RightPanelSecond Visibility="condition2"/> </UserControl> RightPanelFirst and RightPanelSecond have the following xaml: <UserControl> <... content here...> <CheckBox IsChecked="{Binding CurrentObject.ComplexProperty.SimpleProperty1, Mode=TwoWay}"> <CheckBox IsChecked="{Binding CurrentObject.ComplexProperty.SimpleProperty2, Mode=TwoWay}" x:Name="cbSecond"> <TextBox IsEnabled="{Binding IsChecked, ElementName=cbSecond}"/> </UserControl> So, my actual steps: Check both checkboxes (object values are set to true) Make other actions in code behind which modify CurrentObject. Then i want UI to reflect the changes, so I call NotifyPropertyChanged("CurrentObject"); SimpleProperty1 remains the same, but SimpleProperty2 resets to false I have no idea why this happens, can anyone help me please? Silverlight drives me mad.

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  • changing the serialization procedure for a graph of objects (.net framework)

    - by pierusch
    Hello I'm developing a scientific application using .net framework. The application depends heavily upon a large data structure (a tree like structure) that has been serialized using a standard binaryformatter object. The graph structure looks like this: <serializable()>Public class BigObjet inherits list(of smallObject) end class <serializable()>public class smallObject inherits list(of otherSmallerObjects) end class ... The binaryFormatter object does a nice job but it's not optimized at all and the entire data structure reaches around 100Mb on my filesystem. Deserialization works too but it's pretty slow (around 30seconds on my quad core). I've found a nice .dll on codeproject (see "optimizing serialization...") so I wrote a modified version of the classes above overriding the default serialization/deserialization procedure reaching very good results. The problem is this: I can't lose the data previosly serialized with the old version and I'd like to be able to use the new serialization/deserialization method. I have some ideas but I'm pretty sure someone will be able to give me a proper and better advice ! use an "helper" graph of objects who takes care of the entire serialization/deserialization procedure reading data from the old format and converting them into the classes I nedd. This could work but the binaryformatter "needs" to know the types being serialized so........ :( modify the "old" graph to include a modified version of serialization procedure...so I'll be able to deserialize old file and save them with the new format......this doesn't sound too good imho. well any help will be higly highly appreciated :)

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  • Protecting critical sections based on a condition in C#

    - by NAADEV
    Hello, I'm dealing with a courious scenario. I'm using EntityFramework to save (insert/update) into a SQL database in a multithreaded environment. The problem is i need to access database to see whether a register with a particular key has been already created in order to set a field value (executing) or it's new to set a different value (pending). Those registers are identified by a unique guid. I've solved this problem by setting a lock since i do know entity will not be present in any other process, in other words, i will not have same guid in different processes and it seems to be working fine. It looks something like that: static readonly object LockableObject = new object(); static void SaveElement(Entity e) { lock(LockableObject) { Entity e2 = Repository.FindByKey(e); if (e2 != null) { Repository.Insert(e2); } else { Repository.Update(e2); } } } But this implies when i have a huge ammount of requests to be saved, they will be queued. I wonder if there is something like that (please, take it just as an idea): static void SaveElement(Entity e) { (using ThisWouldBeAClassToProtectBasedOnACondition protector = new ThisWouldBeAClassToProtectBasedOnACondition(e => e.UniqueId) { Entity e2 = Repository.FindByKey(e); if (e2 != null) { Repository.Insert(e2); } else { Repository.Update(e2); } } } The idea would be having a kind of protection that protected based on a condition so each entity e would have its own lock based on e.UniqueId property. Any idea?

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  • How to read an xs:any response using CXF Generated Client?

    - by mfcabrera
    Hi, When consuming a webserice with CXF 2.1.4 (the generated client) I am having problem getting the response based on the following XSD snippet in the WSDL. CXF Generates a List representing it, but when I execute the service, the response comes null. I used wireshark to what I was reciving and indeed the response XMl is coming as expected, but CXF just give me null object. Below the XSD of the response object. And <!--- chunk --> <s:element name="GestionSIIFResponse"> <s:complexType> <s:sequence> <s:element minOccurs="0" maxOccurs="1" name="GestionSIIFResult"> <s:complexType mixed="true"> <s:sequence> <s:any /> </s:sequence> </s:complexType> </s:element> </s:sequence> </s:complexType> </s:element> <!--- chunk --> And this is the response I am getting from the service: <soap:Body> <GestionSIIFResponse xmlns="http://tempuri.org/"> <GestionSIIFResult> <Siif xmlns=""> <Pagina>NUY001B</Pagina> <Exitos> <ExitoRep> <CodExito>SIL0082</CodExito> <DesExito>La transaccion se ha aplicado satisfactoriamente</DesExito> </ExitoRep> </Exitos> <InformacionCab/> <Repeticiones/> </Siif> </GestionSIIFResult> </GestionSIIFResponse>

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  • How can I extend a LINQ-to-SQL class without having to make changes every time the code is generated

    - by csharpnoob
    Hi, Update from comment: I need to extend linq-to-sql classes by own parameters and dont want to touch any generated classes. Any better suggestes are welcome. But I also don't want to do all attributes assignments all time again if the linq-to-sql classes are changing. so if vstudio generates new attribute to a class i have my own extended attributes kept separate, and the new innerited from the class itself Original question: i'm not sure if it's possible. I have a class car and a class mycar extended from class car. Class mycar has also a string list. Only difference. How can i cast now any car object to a mycar object without assigning all attributes each by hand. Like: Car car = new Car(); MyCar mcar = (MyCar) car; or MyCar mcar = new MyCar(car); or however i can extend car with own variables and don't have to do always Car car = new Car(); MyCar mcar = new MyCar(); mcar.name = car.name; mcar.xyz = car.xyz; ... Thanks.

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  • Webinvoke to POST JSON with ajax call

    - by G-Man
    This is my first time that I an using WCF Service with Knockout. I want to POST an entire view model as a JSON object with an ajax call. This is the error message that I get: Endpoints using 'UriTemplate' cannot be used with 'System.ServiceModel.Description.WebScriptEnablingBehavior' I have noticed that some developers send each value as a parameter which I feel is unnecessary especially if you work with a big object. This is my WCF method: [OperationContract] [WebInvoke(UriTemplate = "AddNewEvent?newEvent", Method = "POST", ResponseFormat = WebMessageFormat.Json, RequestFormat = WebMessageFormat.Json)] public bool AddNewEvent(Models.DAL_CRMEvents newEvent) { Entities.CRMEntities dbCRM = new Entities.CRMEntities(); //Models.CRMEvents crmEvent = new Models.CRMEvents(); Entities.Event crmEvent = new Entities.Event(); crmEvent.EventDateCreated = Convert.ToDateTime(newEvent.DateCreated); crmEvent.EventActive = true; crmEvent.EventDescription = newEvent.Description; crmEvent.EventDate = Convert.ToDateTime(newEvent.Date); crmEvent.EventTimeStart = TimeSpan.Parse(newEvent.TimeStart); crmEvent.EventTimeEnd = TimeSpan.Parse(newEvent.TimeEnd); crmEvent.EventAllDay = newEvent.AllDay; dbCRM.AddToEvent(crmEvent); return true; } This is my ajax function function SaveEvent (data) { var s = { newEvent: ko.mapping.toJS(data) } alert(data.AllDay()); $.ajax({ type: "POST", url: "../Services/CRMDataService.svc/AddNewEvent", data: JSON.stringify(s), contentType: "application/json; charset=utf-8", dataType: "JSON", success: function (result) { alert(result); }, error: function (jqXHR, textStatus, errorThrown) { if (textStatus == "error" && errorThrown != "") { var n = noty({ text: errorThrown, type: 'warning', dismissQueue: false, modal: true, layout: 'center', theme: 'defaults', callback: { } }) } } }) }

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  • What to pass parameters to start an workflow through WCF

    - by Rubens Farias
    It's possible to define some start values to an workflow using WorkflowInstance.CreateWorkflow, like this: using(WorkflowRuntime runtime = new WorkflowRuntime()) { Dictionary<string, object> parameters = new Dictionary<string, object>(); parameters.Add("First", "something"); parameters.Add("Second", 42); WorkflowInstance instance = runtime.CreateWorkflow(typeof(MyStateMachineWorkflow), parameters); instance.Start(); waitHandle.WaitOne(); } This way, a MyStateMachineWorkflow instance is created and First and Second public properties gets that dictionary values. But I'm using WCF; so far, I managed to create a Start method which accepts that two arguments and I set that required fields by using bind on my ReceiveActivity: using (WorkflowServiceHost host = new WorkflowServiceHost(typeof(MyStateMachineWorkflow))) { host.Open(); ChannelFactory<IMyStateMachineWorkflow> factory = new ChannelFactory<IMyStateMachineWorkflow>("MyStateMachineWorkflow"); IMyStateMachineWorkflow proxy = factory.CreateChannel(); // set this values through binding on my ReceiveActivity proxy.Start("something", 42); } While this works, that create an anomaly: that method should be called only and exactly once. How can I start an workflow instance through WCF passing those arguments? On my tests, I just actually interact with my workflow through wire after I call that proxy method. Is there other way?

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  • I want just the insert query for a temp table.

    - by John Stephen
    Hi..I am using C#.Net and Sql Server ( Windows Application ). I had created a temporary table. When a button is clicked, temporary table (#tmp_emp_details) is created. I am having another button called "insert Values" and also 5 textboxes. The values that are entered in the textbox are used and whenever com.ExecuteNonQuery(); line comes, it throws an error message Invalid object name '#tbl_emp_answer'.. Below is the set of code.. Please give me a solution. Code for insert (in insert value button): private void btninsertvalues_Click(object sender, EventArgs e) { username = txtusername.Text; examloginid = txtexamloginid.Text; question = txtquestion.Text; answer = txtanswer.Text; useranswer = txtanswer.Text; SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=tempdb;Integrated Security=True;"); SqlCommand com = new SqlCommand("Insert into #tbl_emp_answer values('"+username+"','"+examloginid+"','"+question+"','"+answer+"','"+useranswer+"')", con); con.Open(); com.ExecuteNonQuery(); con.Close(); }

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  • std::vector elements initializing

    - by Chameleon
    std::vector<int> v1(1000); std::vector<std::vector<int>> v2(1000); std::vector<std::vector<int>::const_iterator> v3(1000); How elements of these 3 vectors initialized? About int, I test it and I saw that all elements become 0. Is this standard? I believed that primitives remain undefined. I create a vector with 300000000 elements, give non-zero values, delete it and recreate it, to avoid OS memory clear for data safety. Elements of recreated vector were 0 too. What about iterator? Is there a initial value (0) for default constructor or initial value remains undefined? When I check this, iterators point to 0, but this can be OS When I create a special object to track constructors, I saw that for first object, vector run the default constructor and for all others it run the copy constructor. Is this standard? Is there a way to completely avoid initialization of elements? Or I must create my own vector? (Oh my God, I always say NOT ANOTHER VECTOR IMPLEMENTATION) I ask because I use ultra huge sparse matrices with parallel processing, so I cannot use push_back() and of course I don't want useless initialization, when later I will change the value.

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  • client-side data storage and retrieval with html and javascript

    - by pedalpete
    I'm building what I am hoping to be a fairly simple, quick and dirty demo app. So far, I've managed to build a bunch of components using only html and javascript. I know that eventually I'll hook-up a db, but at this point I'm just trying to show off some functionality. In the page, a user can select a bunch of other users (like friends). Then they go to a separate html page and there is some sorting info based on the selected users. So my first attempt was to put the selected users object into a cookie, and retrieve the cookie on the second page. Unfortunately, if the user changed their selection, the cookie wasn't getting updated, and my searches on StackOverflow seemed to say that deleting and updating cookies is unreliable. I tried function updateCookie(updatedUserList){ jQuery.cookie('userList',null); jQuery.cookie('userList',updatedUserList); } but though it set the cookie to null, it wouldn't update it on the second value. So I decided to put the selected users object into a form. Unfortunately, it looks like I can't retrieve the contents from the form on the client-side, only on the server-side. Is there another way to do this? I've worked in PHP and Rails, but I'm trying to do this quickly and simply before building it out into something larger and am trying to avoid any server-side processing for now, which I have managed to do up to this point.

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  • Get Nhibernate entity and complete it from a web service.

    - by Nour Sabouny
    Hi every one. let's say that i have an order system. each "Order" references a "Customer" Object. when i fill the orders list in Data Access Layer, the customer object should be brought from a Customer Web Service "WCF". so i didn't map the Customer property in the Order mapping class, Id(o => o.OrderID).GeneratedBy.Identity(); //References(o => o.Customer).Not.Nullable().Column("CustomerID"); HasMany(o => o.Details).KeyColumn("OrderID").Cascade.AllDeleteOrphan(); Map(c => c.CustomerID).Not.Nullable(); and asked the nhibernate session to get me the orders list. and tried to loop on every order in the list to fill it's customer property, doe's any body have a good idea for this ???? IList<Order> lst = Session.CreateCriteria<Order>().List<Order>(); foreach (Order order in lst) order.Customer = serviceProxy.GetCustomerByID(order.CustomerID);

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  • Returning pointers in a thread-safe way.

    - by Roddy
    Assume I have a thread-safe collection of Things (call it a ThingList), and I want to add the following function. Thing * ThingList::findByName(string name) { return &item[name]; // or something similar.. } But by doing this, I've delegated the responsibility for thread safety to the calling code, which would have to do something like this: try { list.lock(); // NEEDED FOR THREAD SAFETY Thing *foo = list.findByName("wibble"); foo->Bar = 123; list.unlock(); } catch (...) { list.unlock(); throw; } Obviously a RAII lock/unlock object would simplify/remove the try/catch/unlocks, but it's still easy for the caller to forget. There are a few alternatives I've looked at: Return Thing by value, instead of a pointer - fine unless you need to modify the Thing Add function ThingList::setItemBar(string name, int value) - fine, but these tend to proliferate Return a pointerlike object which locks the list on creation and unlocks it again on destruction. Not sure if this is good/bad practice... What's the right approach to dealing with this?

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  • Checkboxes in ADF are initially null, where I want them to be 0

    - by Mark Tielemans
    I am using ADF in JDeveloper and don´t have any experience with either of the two. Now I´ve run into quite some trouble yet, but for this particular thing I decided to consult the wisom of stackoverflow. The thing is, I have an edit form for an object that contains 3 checkboxes. The checked values are set to 1, unchecked to 0. In my database, the values are NOT NULL, and I want to keep it that way. The thing is, in the edit form, if the user submits the form leaving any boxes unchecked, it will result in an error, because the unchecked box values apparently remain null. Only after checking and then unchecking the boxes again, their values will be '0' rather than null. I've tried some things, including making the attributes mandatory in the domain BCD, but that just gives a bit more neat error message.. Any help would be greatly appreciated!! EDIT I made a little progress thanks to the guide provided by Joe, but still run into problems. I changed the values that should be checkboxes in my model, making them BOOLEANs where the table columns are NUMBERs (All are also mandatory and have a default value of 0). This automatically changed the corresponding View Object too. In the Application module, this now works great. It shows checkboxes, a checked one will return 1, an untouched one will return 0. However, I deleted the old form, and inserted a new one using the corresponding Data Control. I gave these values the checkbox type. I still had to edit the bindings (which I think reflects the problem, as this is not the case with, say, a model-level defined LOV) and gave them 1 for checked and 0 for unchecked. However, now apart from the original problem still occurring, also the checkboxes cannot be unchecked after checking, and return 0 when checked (and null when left untouched). Even though this has created new problems, it works correctly in my AM. Does someone know what I'm doing wrong in my Swing form?

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  • Jquery drag /drop and clone

    - by Sajeev
    Hi I need to achive this .. I have a set of droppable items ( basically I am droping designs on a apparel ) and I am dropping a clone.. If I don't like the dropped object (designs) - I want to delete that by doing something like hidden . But I am unable to do that. Please help me.. here is the code var clone; $(document).ready(function(){ $(".items").draggable({helper: 'clone',cursor: 'hand'}); $(".droparea").droppable({ accept: ".items", hoverClass: 'dropareahover', tolerance: 'pointer', drop: function(ev, ui) { var dropElemId = ui.draggable.attr("id"); var dropElem = ui.draggable.html(); clone = $(dropElem).clone(); // clone it and hold onto the jquery object clone.id="newId"; clone.css("position", "absolute"); clone.css("top", ui.absolutePosition.top); clone.css("left", ui.absolutePosition.left); clone.draggable({ containment: 'parent' ,cursor: 'crosshair'}); $(this).append(clone); alert("done dragging "); /lets assume I have a delete button when I click that clone should dissapear so that I can drop another design - but the following code has no effect //and the item is still visible , how to make it dissapear ? $('#newId').css("visibility","hidden"); } }); });

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  • WP7 BarcodeManager - Invalid cross-thread access

    - by rpf
    I'm trying to use Windows Phone 7 Silverlight ZXing Barcode Scanning Library but I'm having some problems. I'm using a background worker to check the image, but when I do this: WP7BarcodeManager.ScanBarcode(this.Image, BarcodeResults_Finished); The code throws an exception: Invalid cross-thread access. Here is my code... void photoChooserTask_Completed(object sender, PhotoResult e) { if (e.TaskResult == TaskResult.OK) { ShowImage(); System.Windows.Media.Imaging.BitmapImage bmp = new System.Windows.Media.Imaging.BitmapImage(); bmp.SetSource(e.ChosenPhoto); imgCapture.Source = bmp; this.Image = new BitmapImage(); this.Image.SetSource(e.ChosenPhoto); progressBar.Visibility = System.Windows.Visibility.Visible; txtStatus.Visibility = System.Windows.Visibility.Collapsed; worker.RunWorkerAsync(); } else ShowMain(); } void worker_DoWork(object sender, DoWorkEventArgs e) { try { Thread.Sleep(2000); WP7BarcodeManager.ScanMode = com.google.zxing.BarcodeFormat.UPC_EAN; WP7BarcodeManager.ScanBarcode(this.Image, BarcodeResults_Finished); } catch (Exception ex) { Debug.WriteLine("Error processing image.", ex); } } How can I solve this?

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  • Which class should store the lookup table?

    - by max
    The world contains agents at different locations, with only a single agent at any location. Each agent knows where he's at, but I also need to quickly check if there's an agent at a given location. Hence, I also maintain a map from locations to agents. I have a problem deciding where this map belongs to: class World, class Agent (as a class attribute) or elsewhere. In the following I put the lookup table, agent_locations, in class World. But now agents have to call world.update_agent_location every time they move. This is very annoying; what if I decide later to track other things about the agents, apart from their locations - would I need to add calls back to the world object all across the Agent code? class World: def __init__(self, n_agents): # ... self.agents = {} self.agent_locations = {} for id in range(n_agents): x, y = self.find_location() agent = Agent(self,x,y) self.agents.append(agent) self.agent_locations[x,y] = agent def update_agent_location(self, agent, x, y): del self.agent_locations[agent.x, agent.y] self.agent_locations[x, y] = agent def update(self): # next step in the simulation for agent in self.agents: agent.update() # next step for this agent # ... class Agent: def __init__(self, world, x, y): self.world = world self.x, self.y = x, y def move(self, x1, y1): self.world.update_agent_location(self, x1, y1) self.x, self.y = x1, y1 def update(): # find a good location that is not occupied and move there for x, y in self.valid_locations(): if not self.location_is_good(x, y): continue if self.world.agent_locations[x, y]: # location occupied continue self.move(x, y) I can instead put agent_locations in class Agent as a class attribute. But that only works when I have a single World object. If I later decide to instantiate multiple World objects, the lookup tables would need to be world-specific. I am sure there's a better solution... EDIT: I added a few lines to the code to show how agent_locations is used. Note that it's only used from inside Agent objects, but I don't know if that would remain the case forever.

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  • Can I get the item type from a BindingSource?

    - by Preston
    I would like to get the Type of item that a BindingSource is hooked up to or configured for. The BindingSource.DataSource property can be set to an object, list, or type. If it is a Type, it obviously does not have an bound item yet, but I would still like to get the Type. For a List, I need the item Type, not the list type. There is a method BindingSource.GetItemProperties, that accomplishes most of what I need. It gets the PropertyDescriptors for the Type, list item, or object specified by the DataSource and DataMember. The reason I ask, is that I have some components that I would like to re-use, but they are currently setup to work off of an item Type. The Type is mainly used to get PropertyInfos and then build a UI, but PropertyInfo and PropertyDescriptor is not exactly the same, so it is not immediately apparent that they can be reworked to use a PropertyDescriptor collection instead. Then there is cascading refactoring of everything already using these components and that adds up to a lot of work that I would rather not do. I've looked through the API docs for for a good way to do this, but so far I have not had any luck. Am I missing something or is this just something I can not or should not be doing?

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