Search Results

Search found 40226 results on 1610 pages for 'object relational model'.

Page 459/1610 | < Previous Page | 455 456 457 458 459 460 461 462 463 464 465 466  | Next Page >

  • How to read from a method that returns a filehandle in perl?

    - by Ryan Thompson
    I have an object with a method that returns a filehandle, and I want to read from that handle. The following doesn't work, because the right angle bracket of the method call is interpreted as the closing angle bracket of the input reader: my $input = <$object->get_handle()>; That gets parsed as: my $input = ( < $object- > ) get_handle() >; which is obviously a syntax error. Is there any way I can perform a method call within an angle operator, or do I need to break it into two steps like this? my $handle = $object->get_handle(); my $input = <$handle>;

    Read the article

  • How can I avoid the overflow when wheel scolling WPF DataGrid

    - by Jan Bannister
    When I use the mouse wheel to scroll the WPF Toolkit DataGrid on a Vista 64 Machine I get a cryptic low level error: at System.IntPtr.op_Explicit(IntPtr value) at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) I logged an issue on CodePlex. But has anyone found a way to resolve this already?

    Read the article

  • Copy constructor with more than one parameter

    - by Ravi Gupta
    I am learning C++ and was reading copy constructor from the C++: The Complete Reference. The books says that It is permissible for a copy constructor to have additional parameters as long as they have default arguments defined for them. However, in all cases the first parameter must be a reference to the object doing the initializing. But I am confused that how we are going to pass those additional parameters? I am sure there should be some way which is not given in the book and which I am unable to figure out. Can anyone help me out? EDIT: Also is it possible to pass these extra parameters in all three cases i.e. ¦ When one object explicitly initializes another, such as in a declaration ¦ When a copy of an object is made to be passed to a function ¦ When a temporary object is generated (most commonly, as a return value)

    Read the article

  • Recycle Freed Objects

    - by uray
    suppose I need to allocate and delete object on heap frequently (of arbitrary size), is there any performance benefit if instead of deleting those objects, I will return it back to some "pool" to be reused later? would it give benefit by reduce heap allocation/deallocation?, or it will be slower compared to memory allocator performance, since the "pool" need to manage a dynamic collection of pointers. my use case: suppose I create a queue container based on linked list, and each node of that list are allocated on the heap, so every call to push() and pop() will allocate and deallocate that node: ` template <typename T> struct QueueNode { QueueNode<T>* next; T object; } template <typename T> class Queue { void push(T object) { QueueNode<T>* newNode = QueueNodePool<T>::get(); //get recycled node if(!newNode) { newNode = new QueueNode<T>(object); } // push newNode routine here.. } T pop() { //pop routine here... QueueNodePool<T>::store(unusedNode); //recycle node return unusedNode->object; } } `

    Read the article

  • LINQ to SQL: On load processing of lazy loaded associations

    - by Matt Holmes
    If I have an object that lazy loads an association with very large objects, is there a way I can do processing at the time the lazy load occurs? I thought I could use AssociateWith or LoadWith from DataLoadOptions, but there are very, very specific restrictions on what you can do in those. Basically I need to be notified when an EntitySet< decides it's time to load the associated object, so I can catch that event and do some processing on the loaded object. I don't want to simply walk through the EntitySet when I load the parent object, because that will force all the lazy loaded items to load (defeating the purpose of lazy loading entirely).

    Read the article

  • NSData release is not reclaiming memory

    - by ctpenrose
    iPhoneOS 3.2 I use NSKeyedUnarchiver's unarchiveObjectWithFile: to load a custom object that contains a single large NSData and another much smaller object. The dealloc method in my custom object gets called, the NSData object is released, its retainCount == 1 just before. Physical memory does not decrement by any amount, let alone a fraction of the NSData size, and with repetition memory warnings are reliably generated: I have test until I actually received level 2 warnings. =( NSString *archivePath = [[[NSBundle mainBundle] pathForResource:@"lingering"] ofType:@"data"] retain]; lingeringDataContainer = [[NSKeyedUnarchiver unarchiveObjectWithFile:archivePath] retain]; [archivePath release]; [lingeringDataContainer release]; and now the dealloc.... - (void) dealloc { [releasingObject release]; [lingeringData release]; [super dealloc]; } Before release: (gdb) p (int) [(NSData *) lingeringData retainCount] $1 = 1 After: (gdb) p (int) [(NSData *) lingeringData retainCount] Target does not respond to this message selector.

    Read the article

  • Django ForeignKey created empty?

    - by Scott Willman
    This seems very basic and I must be missing something, but here goes anyways... With two models like so: class School(models.Model): name = models.CharField("Official School Name", max_length=128) address = models.TextField("Address of the School", max_length=256) mascot = models.CharField("Name of the School Mascot", max_length=128) class StudentProfile(models.Model): name = models.CharField(max_length=128) school = models.ForeignKey(School) If the student gets created before the school, how do I give 'school' a default empty value? Is it blank or null or what? Thanks!

    Read the article

  • How do I get the number of objects per day using django?

    - by Keith
    I have a django model with a DateTimeField. class Point(models.Model): somedata = models.CharField(max_length=256) time = models.DateTimeField() I want to get a count of the number of these objects for each day. I can do this with the following SQL query, but don't know how to do it through django. SELECT DATE(`time`), Count(*) FROM `app_point` GROUP BY DATE(`time`) Being able to restrict the results to a date range would also be good.

    Read the article

  • maths: motion depending on time

    - by clamp
    hello, i have a mathematical problem: i have a function where the only parameter is the current time. the return should be a position which is used to place an object on a certain place. int position(int time) { int x = 0; //TODO implement x depending on time return x; } so basically the function is called every frame to put the object in motion. the motion should look like this (this is the actual question): a linear motion for time A, the object moves at constant speed no motion for time B, the object is stopped repeat at 1. thanks!

    Read the article

  • Findbugs warning: Equals method should not assume anything about the type of its argument

    - by Uri
    When running FindBugs on my project, I got a few instances of the error described above. Namely, my overriding versions of equals cast the RHS object into the same type as the object in which the overriding version is defined. However, I'm not sure whether a better design is possible, since AFAIK Java does not allow variance in method parameters, so it is not possible to define any other type for the equals parameter. Am I doing something very wrong, or is FindBugs too eager? A different way to phrase this question is: what is the correct behavior if the object passed to equals is not the same type as an LHS: Is this a false, or should there be an exception? For example: public boolean equals(Object rhs) { MyType rhsMyType = (MyType)rhs; // Should throw exception if(this.field1().equals(rhsMyType.field1())... // Or whatever }

    Read the article

  • Looking for an elegant way to store one-to-many relationship in coredata when order is important

    - by Eric Schweichler
    I've been trying to come up with a way to solve my problem, but every solution I can think of is messy and makes me want to retch. I have a one-to-many relationship, consisting of a Team object that can have many Member objects. When I built my data model using Xcode, I was given the default NSSet in which to store the member objects, Unfortunately Sets are not ordered and I need to preserve the order of the Member objects and I need to know if there are empty spaces between Members. I thought of Using an NSArray in place of the NSSet and creating a dummy Member object in my data store that I could use to mark vacant a spot between to Member objects, but that solution really feels like too much of a hack to me. Since I'll always have to filter out this dummy Member from any queries. An NSDictionary would be perfect as I could store the Member object references and their positions as Object-Key pairs, (taking care of both order and vacancies) but apparently CoreData does not support NSDictionary. Has anyone had a similar need, and devised a simple solution?

    Read the article

  • weird FileField url in admin site

    - by panchicore
    My model class TheFile(models.Model): document = models.FileField(upload_to="archivos") The weird HTML admin link: <a hacking_google_maps_and_google_earth.pdf="" archivos="" media="" localhost:8000="" http:="" href="" target="_blank">archivos/Hacking_Google_Maps_And_Google_Earth.pdf</a> If I firebug-edit the href="" it works :S

    Read the article

  • Hos to group the complex list objects by using Linq

    - by Daoming Yang
    I want to select and group the products, and rank them by the number of times they occur. For example, I have an OrderList each of order object has a OrderProductVariantList(OrderLineList), and each of OrderProductVariant object has ProductVariant, and then the ProductVariant object will have a Product object which contains product information. A friend helped me with the following code. It could be compiled, but it did not return any value/result. I used the watch window for the query and it gave me "The name 'query' does not exist in the current context". Can anyone help me? Many thanks. var query = orderList.SelectMany( o => o.OrderLineList ) // results in IEnumerable<OrderProductVariant> .Select( opv => opv.ProductVariant ) .Select( pv => p.Product ) .GroupBy( p => p ) .Select( g => new { Product = g.Key, Count = g.Count() });

    Read the article

  • get average from set of objects in django

    - by dotty
    Hay, i have a simple rating system for a property. You give it a mark out of 5 (stars). The models are defined like this def Property(models.Model) # stuff here def Rating(models.Model) property = models.ForeignKey(Property) stars = models.IntegerField() What i want to do is get a property, find all the Rating objects, collect them, then get the average 'stars' from them. any ideas how to do this?

    Read the article

  • In Ruby, how can I initialize instance variables in new objects of core classes created from literal

    - by Ollie Saunders
    class Object attr_reader :foo def initialize @foo = 'bar' end end Object.new.foo # => 'bar' ''.foo # => nil //.foo # => nil [].foo # => nil I want them all to return 'bar' Am aware that you can do this already: class Object def foo 'bar' end end But I specifically want to initialize a state variable. Also note that this doesn't work. class String alias_method :old_init, :initialize def initialize(*args) super old_init(*args) end end class Object attr_reader :foo def initialize @foo = 'bar' super end end ''.foo # => nil Nor does this: class String attr_reader :foo def initialize @foo = 'bar' end end ''.instance_variables # => [] I'm beginning to think that this isn't actually possible.

    Read the article

  • What is the best way get and hold property reference by name in c#

    - by Jeff Weber
    I want to know if there is a better way (than what I'm currently doing) to obtain and hold a reference to a property in another object using only the object and property string names. Particularly, is there a better way to do this with the new dynamic functionality of .Net 4.0? Here is what I have right now. I have a "PropertyReference<T>" object that takes an object name and property name in the constructor. An Initialize() method uses reflection to find the object and property and stores the property Getter as an Action<T> and the property Setter as an Func<T>. When I want to actually call the property I do something like this: int x = _propertyReference.Get(); or _propertyReference.Set(2); Here is my PropertyReference<T> code. Please dissect and make suggestions for improvement. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Reflection; using System.Xml; namespace WindowsFormsApplication2 { public class PropertyReference<T> : IPropertyReference { public string ComponentName { get; set; } public string PropertyName { get; set; } public bool IsInitialized { get { return (_action != null && _func != null); } } Action<T> _action; Func<T> _func; public PropertyReference() { } public PropertyReference(string componentName, string propertyName) { ComponentName = componentName; PropertyName = propertyName; } public void Initialize(IEntity e) { Object component = e.GetByName(ComponentName); if (component == null) return; Type t = e.GetByName(ComponentName).GetType(); PropertyInfo pi = t.GetProperty(PropertyName); _action = (T a) => pi.SetValue(component, a, null); _func = () => (T)pi.GetValue(component, null); } public void Reset() { _action = null; _func = null; } public void Set(T value) { _action.Invoke(value); } public T Get() { return _func(); } } } Note: I can't use the "Emit" functionality as I need this code to work on the new Windows Phone 7 and that does not support Emit.

    Read the article

  • MVC: How do i declare the name value using DropDownListFor

    - by frosty
    I have the following dropdownlist in mvc <%= Html.DropDownListFor(c => c.Address.Id, new SelectList(Model.Addresses, "id", "Name", Model.Address.Id), "-- New Address --", new { @name = "[" + orderItemAddressCount + "].AddressId" })%> I'm trying to overwrite the name value on the dropdownlist. this is the markup i get <select id="Address_Id" name="Address.Id"><option value="">-- New Address --</option> This is the markup i want -- New Address -- How do i declare the name value using DropDownListFor?

    Read the article

  • Best way to code this, string to map conversion in Groovy

    - by Daxon
    I have a string like def data = "session=234567893egshdjchasd&userId=12345673456&timeOut=1800000" I want to convert it to a map ["session", 234567893egshdjchasd] ["userId", 12345673456] ["timeout", 1800000] This is the current way I am doing it, def map = [:] data.splitEachLine("&"){ it.each{ x -> def object = x.split("=") map.put(object[0], object[1]) } } It works, but is there a more efficient way?

    Read the article

  • How do I use Django to insert a Geometry Field into the database?

    - by alex
    class LocationLog(models.Model): user = models.ForeignKey(User) utm = models.GeometryField(spatial_index=True) This is my database model. I would like to insert a row. I want to insert a circle at point -55, 333. With a radius of 10. How can I put this circle into the geometry field? Of course, then I would want to check which circles overlap a given circle. (my select statement)

    Read the article

  • jquery - detect if selector returns null

    - by peirix
    What is the best way to detect if a jQuery-selector returns an empty object. If you do: alert($('#notAnElement')); you get [object Object], so the way I do it now is: alert($('#notAnElement').get(0)); which will write "undefined", and so you can do a check for that. But it seems very bad. What other way is there?

    Read the article

  • MSXML2.ServerXMLHTTP.4.0 Source?

    - by Frank V
    Where does the object "MSXML2.ServerXMLHTTP.4.0" come from? Which install package? I'm attempting to do the following: Set oXMLHTTP = CreateObject("MSXML2.ServerXMLHTTP.4.0") This attempt fails on my development machine (no object is returned) but it is successful on my collage's development machine. Obviously he has something installed that I don't or vice versa but where does this object, dll, etc come from? What would I need to install to get this call to work. For the record, changing the object to a different version isn't an option because code that this depends on was tested for several days against this specific version. We'd have to go back and test again... To expand on this question, how can I tell which version of MS XML is currently installed?

    Read the article

  • Why are virtual methods considered early bound?

    - by AspOnMyNet
    One definition of binding is that it is the act of replacing function names with memory addresses. a) Thus I assume early binding means function calls are replaced with memory addresses during compilation process, while with late binding this replacement happens during runtime? b) Why are virtual methods also considered early bound (thus the target method is found at compile time, and code is created that will call this method)? As far as I know, with virtual methods the call to actual method is resolved only during runtime and not compile time?! thanx EDIT: 1) A a=new A(); a.M(); As far as I know, it is not known at compile time where on the heap (thus at which memory address ) will instance a be created during runtime. Now, with early binding the function calls are replaced with memory addresses during compilation process. But how can compiler replace function call with memory address, if it doesn’t know where on the heap will object a be created during runtime ( here I’m assuming the address of method a.M will also be at same memory location as a )? 2) v-table calls are neither early nor late bound. Instead there's an offset into a table of function pointers. The offset is fixed at compile time, but which table the function pointer is chosen from depends on the runtime type of the object (the object contains a hidden pointer to its v-table), so the final function address is found at runtime. But assuming the object of type T is created via reflection ( thus app doesn’t even know of existence of type T ), then how can at compile time exist an entry point for that type of object?

    Read the article

< Previous Page | 455 456 457 458 459 460 461 462 463 464 465 466  | Next Page >