Search Results

Search found 9353 results on 375 pages for 'implementation phase'.

Page 253/375 | < Previous Page | 249 250 251 252 253 254 255 256 257 258 259 260  | Next Page >

  • Does this singleton pattern make sense?

    - by dontWatchMyProfile
    @implementation MySingletonClass static MySingletonClass *sharedInstance = nil; + (MySingletonClass*)sharedInstance { @synchronized(self) { if (sharedInstance == nil) { sharedInstance = [[self alloc] init]; } } return sharedInstance; } + (id)alloc { @synchronized(self) { if (sharedInstance == nil) { sharedInstance = [super alloc]; return sharedInstance; } } return nil; } + (id)allocWithZone:(NSZone *)zone { @synchronized(self) { if (sharedInstance == nil) { sharedInstance = [super allocWithZone:zone]; return sharedInstance; } } return nil; } -(id)init { self = [super init]; if (self != nil) { // initialize stuff here } return self; } @end Not sure if it's ok to overwrite both alloc and allocWithZone: like this...?

    Read the article

  • User error reporting in ASP.NET.

    - by eugeneK
    I want to build user friendly error reporting. Wrong input, db connection errors and such. Problem is i need the same module be implemented for 3 different systems and to use jQuery UI modal boxes for UI. when i redirect to another page ie. db connection error i redirect to error page when i use return to same page ie. input value 1 bigger than value 2 when it should be other way around ASP.NET Ajax UpdatePanel errors, wrong input for controls within UpdatePanel that doesn't do regular postpacks. thanks for any help with implementation...

    Read the article

  • Friendness and derived class

    - by ereOn
    Hi, Let's say I have the following class hierarchy: class Base { protected: virtual void foo() = 0; friend class Other; }; class Derived : public Base { protected: void foo() { /* Some implementation */ }; }; class Other { public: void bar() { Derived* a = new Derived(); a->foo(); // Compiler error: foo() is protected within this context }; }; I guess I could change it too a->Base::foo() but since foo() is pure virtual in the Base class, the call will result in calling Derived::foo() anyway. However, the compiler seems to refuse a->foo(). I guess it is logical, but I can't really understand why. Am I missing something ? Can't (shouldn't) it handle this special case ? Thank you.

    Read the article

  • Can I add a custom method to Core Data-generated classes?

    - by Andy
    I've got a couple of Core Data-generated class files that I'd like to add custom methods to. I don't need to add any instance variables. How can I do this? I tried adding a category of methods: // ContactMethods.h (my category on Core Data-generated "Contact" class) #import "Contact.h" @interface Contact (ContactMethods) -(NSString*)displayName; @end ... // ContactMethods.m #import "ContactMethods.h" @implementation Contact (ContactMethods) -(NSString*)displayName { return @"Some Name"; // this is test code } @end This doesn't work, though. I get a compiler message that "-NSManagedObject may not respond to 'displayName' " and sure enough, when I run the app, I don't get "Some Name" where I should be seeing it.

    Read the article

  • Extension methods on a static object

    - by Max Malygin
    I know (or so I hear) that writing extension methods for a single stand alone .net class (not an implementation of IEnumerable) is potential code smell. However, for the sake of making the life easier I need to attach a method to the ConfigurationManager class in asp.net. It's a static object so this won't work: public static List<string> GetSupportedDomains(this ConfigurationManager manager) { //the manager needs to be static. } So the question is - is it possible to write an extension method for a static class in .net?

    Read the article

  • How to call a function from a shared library?

    - by Frank
    What is the easiest and safest way to call a function from a shared library / dll? I am mostly interested in doing this on linux, but it would be better if there were a platform-independent way. Could someone provide example code to show how to make the following work, where the user has compiled his own version of foo into a shared library? // function prototype, implementation loaded at runtime: std::string foo(const std::string); int main(int argc, char** argv) { LoadLibrary(argv[1]); // loads library implementing foo std::cout << "Result: " << foo("test"); return 0; } BTW, I know how to compile the shared lib (foo.so), I just need to know an easy way to load it at runtime.

    Read the article

  • Do fields need to be explicitly final to have a "proper" immutable object?

    - by Yishai
    You often read about immutable objects requiring final fields to be immutable in Java. Is this in fact the case, or is it simply enough to have no public mutability and not actually mutate the state? For example, if you have an immutable object built by the builder pattern, you could do it by having the builder assign the individual fields as it builds, or having the builder hold the fields itself and ultimately return the immutable object by passing the values to its (private) constructor. Having the fields final has the obvious advantage of preventing implementation errors (such as allowing code to retain a reference to the builder and "building" the object multiple times while in fact mutating an existing object), but having the Builder store its data inside the object as it is built would seem to be DRYer. So the question is: Assuming the Builder does not leak the Object early and stops itself from modifying the object once built (say by setting its reference to the object as null) is there actually anything gained (such as improved thread safety) in the "immutability" of the object if the object's fields were made final instead?

    Read the article

  • calling resize on std vector of pointers crashed

    - by user11869
    The problem can be reproduced using VS 2013 Express. It crashed when internal vector implementation tried to deallocate the original vector. However, the problem can solved by using 'new' instead of 'malloc'. Anyone can shed some light on this? struct UndirectedGraphNode { int label; vector<UndirectedGraphNode *> neighbors; UndirectedGraphNode(int x) : label(x) {}; }; int main(int argc, char** argv) { UndirectedGraphNode* node1 = (UndirectedGraphNode*)malloc(sizeof(UndirectedGraphNode)); node1->label = 0; node1->neighbors.resize(2); return 0; }

    Read the article

  • WorkFlow and WCF dynamically launching WorkFlows

    - by Raj73
    I have a WF which will be hosted on WCF . The service Contract will contain a single operation containing two parameters. Parameter1 will be a string and will contain the name of the workflow to invoke and parameter two will contain the input for the invoked Work Flow. All operations will take the same parameter. All the operations will return the same return value. I have created the service implementation and I would like to depending on the value of parameter1 start executing the appropriate workflow and return the value (There can be number of workflow classes say Operation1, Operation2...which will be the passed in as the value in Parameter1). How can I instantiate different workflow classes and pass parameters and get the return values from them which I should then pass back to the calling Client. (Also Should I be using ReceiveActivities in all of my Launchable WorkFlow Classes ? ) Any code samples or pointers would help

    Read the article

  • Can a raw Lucene index be loaded by Solr?

    - by wynz
    Some colleagues of mine have a large Java web app that uses a search system built with Lucene Java. What I'd like to do is have a nice HTTP-based API to access those existing search indexes. I've used Nutch before and really liked how simple the OpenSearch implementation made it to grab results as RSS. I've tried setting Solr's dataDir in solrconfig.xml, hoping it would happily pick up the existing index files, but it seems to just ignore them. My main question is: Can Solr be used to access Lucene indexes created elsewhere? Or might there be a better solution?

    Read the article

  • Can I Use EF Across Multiple DBs in One SQLServer Instance?

    - by thomashubschman
    Hello, I have been searching the blogs and articles but I have not found much support for this scenario. I have been poking around EF and realized that I could create views that contained data from multiple databases and then build the EF object model off of those views. Although it works I am not sure about the usual issues of performance, scalability, maintainability. The way I am achieving the connection between databases is by creating associations in the EF model. Does anyone have any information about this type of implementation? Either another solution or commentary on this proposed solution? Thanks, Tom

    Read the article

  • overriding callbacks avoiding attribute pollution

    - by pygabriel
    I've a class that has some callbacks and its own interface, something like: class Service: def __init__(self): connect("service_resolved", self.service_resolved) def service_resolved(self, a,b c): ''' This function is called when it's triggered service resolved signal and has a lot of parameters''' the connect function is for example the gtkwidget.connect, but I want that this connection is something more general, so I've decided to use a "twisted like" approach: class MyService(Service): def my_on_service_resolved(self, little_param): ''' it's a decorated version of srvice_resolved ''' def service_resolved(self,a,b,c): super(MyService,self).service_resolved(a,b,c) little_param = "something that's obtained from a,b,c" self.my_on_service_resolved(little_param) So I can use MyService by overriding my_on_service_resolved. The problem is the "attributes" pollution. In the real implementation, Service has some attributes that can accidentally be overriden in MyService and those who subclass MyService. How can I avoid attribute pollution? What I've thought is a "wrapper" like approach but I don't know if it's a good solution: class WrapperService(): def __init__(self): self._service = service_resolved # how to override self._service.service_resolved callback? def my_on_service_resolved(self,param): ''' '''

    Read the article

  • Can I reproduce Scala's behavior for == ?

    - by JPP
    In Programming in Scala, I can read that the == operator behaves as if it was defined like this: final def == (that: Any): Boolean = if (null eq this) {null eq that} else {this equals that} But there must actually be compiler magic to avoid null pointer exceptions, right? Is there any way for me to replicate this behavior with pure Scala; i.e., have an operator/method return one thing if the receiver is null and another one if it isn't? What I mean is an actual implementation of null eq this. I suppose I can write a "pimp" and then define the method on the wrapper class, but is there a more direct way to do this?

    Read the article

  • UISearchBarDisplayController - Fixed SearchBar

    - by slik
    I've been trying to get UISearchBarDisplayController to not animate, and stay fixed below the navigation bar. Is this even possible, I've been getting some weird results. This is all configured through a storyboard. I am just trying to figure out If I should just create my own implementation of UISearchBarDisplayController since it kinda seems a little impossible to customize it to my need. Clicking the search box When I start searching the top has extra paddding (20pt). It's assuming its on top of the origin y: 0 to prevent overlapping of status bar. I can't click outside or the cancel, x buttons. What happens If I click cancel, before searching

    Read the article

  • Restructured Text - adding title attributes to links

    - by Ant
    Hi all, I am trying to use a jquery lightbox implementation on my website that is generated from Restructured Text. The lightbox takes the title of the link around the images as the caption of the image in the lightbox display. However, I can't seem to find a way in Restructured Text of providing a title attribute on a link - does anyone know of a way of doing so. My Images are defined like so: .. image:: image001.thumb.jpg :alt: Some alt text here :target: image001.jpg So I can add an alt attribute, but not a title. A possible alternative may be to use a target as the reference like so: .. image:: image001.thumb.jpg :alt: Some alt text here :target: image1_ .. _image1: image001.jpg In this latter case, I am not sure how to add attributes to the link defined at the bottom (if it is possible at all)

    Read the article

  • Why can't I register a custom model binder for a List<int>?

    - by quarksoup
    I have an action that looks like public ActionResult GetUsers(List<int> userIds) {//do stuff} The list of userIds can become quite long, so I want to use Json.Net to deserialize it. To do so I created an IModelBinder implementation, which works fine for other objects, but never gets called for a List. The IModelBind looks like this public class JsonBinder : System.Web.Mvc.IModelBinder { public object BindModel(System.Web.Mvc.ControllerContext controllerContext, System.Web.Mvc.ModelBindingContext bindingContext) { //Do model binding stuff using Json.Net } } And I register this model binder with this line ModelBinders.Binders.Add(typeof(List<int>), new JsonBinder()); However the JsonBinder is never called. Why is this? Should I be using a ValueProvider?

    Read the article

  • WCF Client - Best Practise

    - by user1663907
    I just wanted to hear your Opinion about a WCF Client implementation. I have an Server that provides several services like SecurityManager. This service is defined in the Interface ISecurityManager and implemented in the Class SecurityManager. So far everything is fine. On the Client side I want to implement the services calls via a seperated Class. My question is whether I do this also in an SecurityManager Class which implements the same ISecurityManager Interface? What is here the best practise? Thanks.

    Read the article

  • Detecting metadata-only read requests in windows filesystem

    - by HyLian
    Hello, I'm developing a kind of filesystem driver. All of read requests that windows makes to my filesystem goes by the driver implementation. I would like to distinguish between "normal" read requests and those who want to get only the metadata from the file. ( Windows reads first 4K of the file and then stop reading ). Does Windows mark this metadata reads in some way? It would be very useful in order to treat that two kind of operations in a different way. In a typical CreateFile call, we have AccessMode, ShareMode, CreationDisposition and FlagsAndAttributes parameters ( being DWORD ), i'm not sure if it's possible to extract some clue of the operation requested. Thanks for reading :)

    Read the article

  • Is it possible to use AutoMapper to map methods?

    - by Woj
    I have two classes: public class TestClass1 { public int TestInt { get; set; } public void TestMethod() { // Do something } } public class TestClass2 { public int TestInt { get; set; } public void TestMethod() { // Do something } } I want to create interface that I can use for both classes. The easiest solution is to implement the interface on TestClass1 and TestClass2 but I don;t have access to the implementation of these classes (external dll). I was wondering if I can create new interface and use AutoMapper to map TestClass1 and TestClass2 to ITestInterface: public interface ITestInterface { int TestInt { get; set; } void TestMethod(); }

    Read the article

  • Objective C - Custom Getter with inheritance

    - by anhdat
    Recently I have worked with Core Data. When I want to set a default value for some fields, I came up with this problem: So I made a simple represent: We have 2 class Parent and Child, in which Child inherit from Parent. // Parent.h @interface Parent : NSObject @property (strong, nonatomic) NSString *lastName; // Child.h @interface Child : Parent In Parent class, I made a custom getter to set a default value when nothing is set: // Parent.h - (NSString *)lastName { if (_lastName) { return _lastName; } else { return @"Parent Default Name"; } } But I cannot make a custom default value for the field "name" which Child inherits from its Parent. // Child.h @implementation Child - (NSString *)lastname { if (super.lastName) { return super.lastName; } else { return @"Child Default Name"; } } Apparently, this method is never called. So my question here is: How can I set a custom getter for the field the Child class inherits from Parent without define an overriding property?

    Read the article

  • how to select distinct rows for a column

    - by Satoru.Logic
    Hi, all. I have a table x that's like the one bellow: id | name | observed_value | 1 | a | 100 | 2 | b | 200 | 3 | b | 300 | 4 | a | 150 | 5 | c | 300 | I want to make a query so that in the result set I have exactly one record for one name: (1, a, 100) (2, b, 200) (5, c, 300) If there are multiple records corresponding to a name, say 'a' in the table above, I just pick up one of them. In my current implementation, I make a query like this: select x.* from x , (select distinct name, min(observed_value) as minimum_val from x group by name) x1 where x.name = x1.name and x.observed_value = x1.observed_value; But I think there may be some better way around, please tell me if you know, thanks in advance.

    Read the article

  • singleton pattern in java- lazy Intialization

    - by flash
    public static MySingleton getInstance() { if (_instance==null) { synchronized (MySingleton.class) { _instance = new MySingleton(); } } return _instance; } 1.is there a flaw with the above implementation of the getInstance method? 2.What is the difference between the two implementations.? public static synchronized MySingleton getInstance() { if (_instance==null) { _instance = new MySingleton(); } return _instance; } I have seen a lot of answers on the singleton pattern in stackoverflow but the question I have posted is to know mainly difference of 'synchronize' at method and block level in this particular case.

    Read the article

  • Tomcat + Struts + OpenID raising ServletExceptions

    - by Rocjoe
    I am working with Tomcat 5.5.x with Struts 1.2 to run a rather large website (large w.r.t. source code). I'm looking to add OpenID to my website, mostly to access attribute exchange to help accelerate the registration process. Every Java implementation for OpenID I have attempted to use will cause a ServletException. Tracing this has been very difficult, but it seems merely instancing any class that makes use of Apache HttpClient will cause the crash. Is this a configuration problem I can address in the JVM, or is it positively wrong to try to initiate an outbound Http request from within an inbound Http request?

    Read the article

  • Shortest distance between points on a toroidally wrapped (x- and y- wrapping) map?

    - by mstksg
    I have a toroidal-ish Euclidean-ish map. That is the surface is a flat, Euclidean rectangle, but when a point moves to the right boundary, it will appear at the left boundary (at the same y value), given by x_new = x_old % width Basically, points are plotted based on: (x_new, y_new) = ( x_old % width, y_old % height) Think Pac Man -- walking off one edge of the screen will make you appear on the opposite edge. What's the best way to calculate the shortest distance between two points? The typical implementation suggests a large distance for points on opposite corners of the map, when in reality, the real wrapped distance is very close. The best way I can think of is calculating Classical Delta X and Wrapped Delta X, and Classical Delta Y and Wrapped Delta Y, and using the lower of each pair in the Sqrt(x^2+y^2) distance formula. But that would involve many checks, calculations, operations -- some that I feel might be unnecessary. Is there a better way?

    Read the article

  • How to test that invalid arguments raise an ArgumentError exception using RSpec?

    - by John Topley
    I'm writing a RubyGem that can raise an ArgumentError if the arguments supplied to its single method are invalid. How can I write a test for this using RSpec? The example below shows the sort of implementation I have in mind. The bar method expects a single boolean argument (:baz), the type of which is checked to make sure that it actually is a boolean: module Foo def self.bar(options = {}) baz = options.fetch(:baz, true) validate_arguments(baz) end def self.validate_arguments(baz) raise(ArgumentError, ":baz must be a boolean") unless valid_baz?(baz) end def self.valid_baz?(baz) baz.is_a?(TrueClass) || baz.is_a?(FalseClass) end end

    Read the article

< Previous Page | 249 250 251 252 253 254 255 256 257 258 259 260  | Next Page >