I want to make a class A friend class of class B. I want to do this as these interact very much and A needs to change internals of class B (which I dont want to expose using public). But I want to make sure it has access to only a few selected functions not all the functions. Example: class A { }; class B { private: void setState();...
I have a table that is storing a list of rules. In my code, I need to retrieve those rules and maintain the list of rules (via. the Repository Pattern) so that I can reuse them. I then need to generate(business logic) a list of objects based on the rules for a particular period of time, eg, a list of holiday objects filtered by the rul...
LLVM has it's own hand rolled alternative to RTTI that is a speed improvement over built-in RTTI and allows dynamic casting to classes with no vtable (dyn_cast). However, it can still be used in exactly the way that dynamic_cast<> is used though it does allow it to be used with more classes. dyn_cast<> template documentation LLVM is a ...
I'm looking at programming/design patterns for the model layer of my application, and am wondering which one fits best with the situation where you are doing a retrieval that involves joins across multiple tables. For example, suppose you have the following tables/relations: Customer --> 1..n Accounts --> 0..n Features where a Feature...
Hello, I'm about to program a mutistep form in my MVC App (Self-made MVC framework) in which no data is to be inserted until the last step is finished. I got the following issues/questions I'd really like to find a kind of pattern to solve this problem, is there any? I want it to be easy the perform a go back action, and get the data...
What would you call a class that wraps some external process Worker (starts and stops it, reads stdin, stdout, etc.)? WorkerFacade? WorkerGateway? WorkerWrapper? ...
Hello all, I am trying to determine the best design pattern to use for a business key validation web service. The basic logic flow is coded below. The program will take a parameter and use a field to help determine the path to take in searching multiple systems where this business key can be found. System1 is searched first, if not f...
When designing my application how many controllers should I have? Is it good practice to have one controller for the entire app, the entire window, or for each class? Additionally how many objects are to many created in the doc window in Interface Builder. Tutorials generally have one called AppController. Do full applications typica...
Hi Im building an app that will use a Core Data model. I pretty new at Objective C and my usual design patterns does not really apply on Core Data and Objective C, at least I can't seem to find examples that confirms they will. I have been through the Apple Developer examples and different sources on the intertubes. It seems that to l...
i wanna know if there is any pattern that can overcome this problem: i have a set of properties that needed to be public to serveral classes and to other classes they should be only readonly, the classes must be public. i do not wanna use reflection or any other bad performance makers i know i can make them RO and implement logic insi...
I'm reading the chapter on the Decorator Pattern in Head First Design Patterns. They use a coffee ordering system as an example to teach the pattern. While the Decorator Pattern seems a useful pattern, it does not seem appropriate for a coffee ordering system. Wouldn't it be simpler to just have a table (or list or some such) of ite...
i see this pattern over and over again and wanted to get opinions: Option 1: On the wire object and Business object composition: On the wire object - the data that is serialized and sent back and forth across machines (client / server, etc). This is a POCO object. For example: public class Order { public int Price; publi...
Imagine the typical type of application where you have a list of items with different properties. E.g. a tree-view with 100 items, each having a name, a rating, a rank-within-the-hottest-items-on-the-planet etc. Probably there are also many-to-many relationships between items and item-catalogs, or between items and item-creators etc etc....
To implement application's GUI I would like to have all the logic to go from one form to another centralized. This GUI manager will behave as a finite state machine. Although I think I have seen this kind of implementation somewhere, I can't find a design pattern that matches with this kind of solution. A form will look like this: publ...
For message based passing systems, what are your "message design patterns" e.g. Limit directed messages (i.e. specific destination) Avoid long cascade chains (i.e. react to MsgA with MsgB, MsgC etc.) Have a system "heartbeat" message Other examples? ...
Hello ladies and gentlemen! I'm new to php and zend framework and fill very uncertain about following: For example, I have two tables: table1: box(id, height, width, length, weight) table2: labels(id, boxid, text, position) labels.boxid -> box.id (labels.boxid is a foreign_key for primary_key box.id) I've generated two separate sta...
I am not very sure what design pattern is the most efficent to use when working with ASP.Net MVC and the Entity Framework, so any guidance is much appreciated! Would you store the context in the Controller-class, or is it better to create a repository? If you would recommend the repo-design, is it required to initialize the context in ...
I have a User model that can hold 1-n UserGroup models, each of which holds data about the user's relationship with a specific group (for example, if they're the admin of the group, when they joined the group, etc.). I'd like to provide some helper methods like isGroupUser() and isGroupAdmin() that work on the entire set of UserGroup mo...
When writing a Silverlight app hooked up to a WCF Web Service, the only option we are presented with in using the Web Service is to make asynchronous calls to the WS interface. i.e. WebService client = new WebService(); client.ServiceMethodCompleted += new EventHandler<Args>(client_Handler); client.ServiceMethodAsync(); client.close()...
First of all, I apologise for the vagueness of the question title and if this has been asked elsewhere already. I struggled to find a similar answer due to the amount of other 'what is this pattern called' questions. I've got the following abstract class: public abstract class PositionProvider<T> : DalProvider<T>, IDalProvider whe...