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  • Using Doctrine to abstract CRUD operations

    - by TomWilsonFL
    This has bothered me for quite a while, but now it is necessity that I find the answer. We are working on quite a large project using CodeIgniter plus Doctrine. Our application has a front end and also an admin area for the company to check/change/delete data. When we designed the front end, we simply consumed most of the Doctrine code right in the controller: //In semi-pseudocode function register() { $data = get_post_data(); if (count($data) && isValid($data)) { $U = new User(); $U->fromArray($data); $U->save(); $C = new Customer(); $C->fromArray($data); $C->user_id = $U->id; $C->save(); redirect_to_next_step(); } } Obviously when we went to do the admin views code duplication began and considering we were in a "get it DONE" mode so it now stinks with code bloat. I have moved a lot of functionality (business logic) into the model using model methods, but the basic CRUD does not fit there. I was going to attempt to place the CRUD into static methods, i.e. Customer::save($array) [would perform both insert and update depending on if prikey is present in array], Customer::delete($id), Customer::getObj($id = false) [if false, get all data]. This is going to become painful though for 32 model objects (and growing). Also, at times models need to interact (as the interaction above between user data and customer data), which can't be done in a static method without breaking encapsulation. I envision adding another layer to this (exposing web services), so knowing there are going to be 3 "controllers" at some point I need to encapsulate this CRUD somewhere (obviously), but are static methods the way to go, or is there another road? Your input is much appreciated.

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  • Generic Abstract Singleton with Custom Constructor in C#

    - by Heka
    I want to write a generic singleton with an external constructor. In other words the constructor can be modified. I have 2 designs in my mind but I don't know whether they are practical or not. First one is to enforce derived class' constructor to be non-public but I do not know if there is a way of it? Second one is to use a delegate and call it inside the constructor? It isn't necessarily to be a constructor. The reason I chose custom constructor is doing some custom initializations. Any suggestions would be appreciated :)

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  • C++ abstract class template + type-specific subclass = trouble with linker

    - by user333279
    Hi there, The project in question is about different endpoints communicating with each other. An endpoint sends events (beyond the scope of the current problem) and can process incoming events. Each event is represented in a generic object as follows: #pragma interface ... // some includes template<typename T> class Event { public: Event(int senderId, Type type, T payload); // Type is an enum Event(int senderId, Type type, int priority, T payload); virtual ~Event(); virtual int getSenderId(); virtual int getPriority(); virtual T getPayload(); void setPriority(const int priority); protected: const int senderId; const Type type; const T payload; int priority; }; It has its implementing class with #pragma implementation tag. An endpoint is defined as follows: #pragma interface #include "Event.h" template<typename T> class AbstractEndPoint { public: AbstractEndPoint(int id); virtual ~AbstractEndPoint(); virtual int getId(); virtual void processEvent(Event<T> event) = 0; protected: const int id; }; It has its implementing class too, but only the constructor, destructor and getId() are defined. The idea is to create concrete endpoints for each different payload type. Therefore I have different payload objects and specific event classes for each type, e.g. Event<TelegramFormatA>, Event<TelegramFormatB> and ConcreteEndPoint for TelegramFormatA, ConcreteEndPoint for TelegramFormatB respectively. The latter classes are defined as class ConcreteEndPoint : AbstractEndPoint<TelegramFormatA> { ... } I'm using g++ 4.4.3 and ld 2.19. Everything compiles nicely, but the linker complaints about undefined references to type-specific event classes, like Event<TelegramFormatA>::Event(....) . I tried explicit instantiation using template class AbstractEndPoint<TelegramFormatA>; but couldn't get past the aforementioned linker errors. Any ideas would be appreciated.

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  • Identifying a class which is extending an abstract class

    - by Simon A. Eugster
    Good Evening, I'm doing a major refactoring of http://wiki2xhtml.sourceforge.net/ to finally get better overview and maintainability. (I started the project when I decided to start programming, so – you get it, right? ;)) At the moment I wonder how to solve the problem I'll describe now: Every file will be put through several parsers (like one for links, one for tables, one for images, etc.): public class WikiLinks extends WikiTask { ... } public class WikiTables extends WikiTask { ... } The files will then be parsed about this way: public void parse() { if (!parse) return; WikiTask task = new WikiLinks(); do { task.parse(this); } while ((task = task.nextTask()) != null); } Sometimes I may want to use no parser at all (for files that only need to be copied), or only a chosen one (e.g. for testing purposes). So before running task.parse() I need to check whether this certain parser is actually necessary/desired. (Perhaps via Blacklist or Whitelist.) What would you suggest for comparing? An ID for each WikiTask (how to do?)? Comparing the task Object itself against a new instance of a WikiTask (overhead)?

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  • Abstract over X

    - by Bruno Bieth
    Sorry for this english related question but I only came across that expression in the context of IT. What does abstracting over something mean ? For example abstracting over objects or abstracting over classes. Thanks

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  • Compiler error when using abstract types

    - by Dylan
    I'm trying to implement a "protocol helper" trait that is responsible for matching up Prompts and Responses. The eventual goal is to have an object that defines the various Prompt and Response classes as subclasses of a sealed trait, then have a class that mixes in the ProtocolSupport trait for that Protocol object. The problem is that my current approach won't compile, even though I'm fairly sure it should. Here's a distilled version of what I've got: trait Protocol { type Response type Prompt <: BasePrompt trait BasePrompt { type Data def validate(response: Response): Validated[Data] } } trait ProtocolSupport[P <: Protocol] { def foo(prompt: P#Prompt, response: P#Response) = { // compiler error prompt.validate(response) } } The compiler doesn't like the response as an argument to prompt.validate: [error] found : response.type (with underlying type P#Response) [error] required: _4.Response where val _4: P [error] prompt.validate(response) [error] ^ This isn't very helpful.. it seems to say that it wants a P.Response but that's exactly what I'm giving it, so what's the problem?

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  • This is more a matlab/math brain teaser than a question

    - by gd047
    Here is the setup. No assumptions for the values I am using. n=2; % dimension of vectors x and (square) matrix P r=2; % number of x vectors and P matrices x1 = [3;5] x2 = [9;6] x = cat(2,x1,x2) P1 = [6,11;15,-1] P2 = [2,21;-2,3] P(:,1)=P1(:) P(:,2)=P2(:) modePr = [-.4;16] TransPr=[5.9,0.1;20.2,-4.8] pred_modePr = TransPr'*modePr MixPr = TransPr.*(modePr*(pred_modePr.^(-1))') x0 = x*MixPr Then it was time to apply the following formula to get myP , where µij is MixPr. I used this code to get it: myP=zeros(n*n,r); Ptables(:,:,1)=P1; Ptables(:,:,2)=P2; for j=1:r for i = 1:r; temp = MixPr(i,j)*(Ptables(:,:,i) + ... (x(:,i)-x0(:,j))*(x(:,i)-x0(:,j))'); myP(:,j)= myP(:,j) + temp(:); end end Some brilliant guy proposed this formula as another way to produce myP for j=1:r xk1=x(:,j); PP=xk1*xk1'; PP0(:,j)=PP(:); xk1=x0(:,j); PP=xk1*xk1'; PP1(:,j)=PP(:); end myP = (P+PP0)*MixPr-PP1 I tried to formulate the equality between the two methods and seems to be this one. To make things easier, I ignored from both methods the summation of matrix P. where the first part denotes the formula that I used, while the second comes from his code snippet. Do you think this is an obvious equality? If yes, ignore all the above and just try to explain why. I could only start from the LHS, and after some algebra I think I proved it equals to the RHS. However I can't see how did he (or she) think of it in the first place.

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  • Best design for generating code from an AST?

    - by Sam Washburn
    I'm working on a pretty complex DSL that I want to compile down into a few high level languages. The whole process has been a learning experience. The compiler is written in java. I was wondering if anyone knew a best practice for the design of the code generator portion. I currently have everything parsed into an abstract syntax tree. I was thinking of using a template system, but I haven't researched that direction too far yet as I would like to hear some wisdom first from stack overflow. Thanks!

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  • django modeling

    - by SledgehammerPL
    Concept: Drinks are made of components. E.g. 10ml of Vodka. In some receipt the component is very particular (10ml of Finlandia Vodka), some not (10 ml of ANY Vodka). I wonder how to model a component to solve this problem - on stock I have particular product, which can satisfy more requirements. The model for now is: class Receipt(models.Model): name = models.CharField(max_length=128) (...) components = models.ManyToManyField(Product, through='ReceiptComponent') def __unicode__(self): return self.name class ReceiptComponent(models.Model): product = models.ForeignKey(Product) receipt = models.ForeignKey(Receipt) quantity = models.FloatField(max_length=9) unit = models.ForeignKey(Unit) class Admin: pass def __unicode__(self): return unicode(self.quantity!=0 and self.quantity or '') + ' ' + unicode(self.unit) + ' ' + self.product.genitive class Product(models.Model): name = models.CharField(max_length = 128) (...) class Admin: pass def __unicode__(self): return self.name class Stock(Store): products = models.ManyToManyField(Product) class Admin: pass def __unicode__(self): return self.name I think about making some table which joins real product (on stock) with abstract product (receiptcomponent). But maybe there's easy solution?

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  • A problem with .NET 2.0 project, using a 3.0 DLL which implements WCF services.

    - by avance70
    I made a client for accessing my WCF services in one project, and all classes that work with services inherit from this class: public abstract class ServiceClient<TServiceClient> : IDisposable where TServiceClient : ICommunicationObject This class is where I do stuff like disposing, logging when the client was called, etc. some common stuff which all service classes would normally do. Everything worked fine, until I got the task to implement this on an old system. I got into a problem when I used this project (DLL) in an other project which cannot reference System.ServiceModel (since it's an old .NET 2.0 software that I still maintain, and upgrading it to 3.0 is out of the question). Here, if I omit where TServiceClient : ICommunicationObject then the project can build, but the ServiceClient cannot use, for example, client.Close() or client.State So, is my only solution to drop the where statement, and rewrite the service classes?

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  • Vector of objects

    - by Paul
    I've got a abstract class class A { public: virtual void somefunction() = ; }; and some different classes that inherit this class: class Ab { public: void somefunction(); }; etc. I want to make a vector containing some objects of these classes (how many depends on input parameters) so I can access these easily later. However I'm a bit lost on how to do this. My best idea is vector<A> *objectsVector; Ab AbObject; objectsVector.push_back(AbObject); However this gives me a huge amout of errors from various .h files in /usr/include/c++ How should i solve this?

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  • @MustOverride annotation?

    - by Harrypotter2k5
    In .NET, one can specify a "mustoverride" attribute to a method in a particular superclass to ensure that subclasses override that particular method. I was wondering whether anybody has a custom java annotation that could achieve the same effect. Essentially what i want is to push for subclasses to override a method in a superclass that itself has some logic that must be run-through. I dont want to use abstract methods or interfaces, because i want some common functionality to be run in the super method, but more-or-less produce a compiler warning/error denoting that derivative classes should override a given method.

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  • When should one use the Abstract, Implements, or extends keywords?

    - by kdavis8
    I'm just now moving from a beginner to intermediate level android programmer in the java language. i can successfully write a game framework of classes that work together to accomplish a task beyond basic things, like hello world. but i'm having issues with some pretty basic OOP concepts; When should i derive from an abstract class? When is it more efficient to use an Interface instead of simply sub classing a parent? Basically, between extends, implements, and the abstract keywords, which keywords should be used instead of the others? i'm not looking for a basic definition, as i know them. i need to no when and why i should apply them to my code? what advantages does one have over the other? which is best for game development?

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  • Is it okay to have many Abstract classes in your application?

    - by JoseK
    We initially wanted to implement a Strategy pattern with varying implementations of the methods in a commmon interface. These will get picked up at runtime based on user inputs. As it's turned out, we're having Abstract classes implementing 3 - 5 common methods and only one method left for a varying implementation i.e. the Strategy. Update: By many abstract classes I mean there are 6 different high level functionalities i.e. 6 packages , and each has it's Interface + AbstractImpl + (series of Actual Impl). Is this a bad design in any way? Any negative views in terms of later extensibility - I'm preparing for a code/design review with seniors.

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  • I am getting this error on each machine after installing ruby and rails, I created one web site and

    - by Santodsh
    D:\PROJECTS\RubyOnRail\webapp\Welcome>ruby script\server => Booting WEBrick => Rails 2.3.4 application starting on http://0.0.0.0:3000 => Call with -d to detach => Ctrl-C to shutdown server [2010-01-31 21:19:34] INFO WEBrick 1.3.1 [2010-01-31 21:19:34] INFO ruby 1.8.6 (2007-09-24) [i386-mswin32] [2010-01-31 21:19:34] INFO WEBrick::HTTPServer#start: pid=6576 port=3000 /!\ FAILSAFE /!\ Sun Jan 31 21:19:38 +0530 2010 Status: 500 Internal Server Error uninitialized constant Encoding c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/depend encies.rb:443:in `load_missing_constant' c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/depend encies.rb:80:in `const_missing' c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/depend encies.rb:92:in `const_missing' c:/ruby/lib/ruby/gems/1.8/gems/sqlite3-0.0.6/lib/sqlite3/encoding.rb:9:in `f ind' c:/ruby/lib/ruby/gems/1.8/gems/sqlite3-0.0.6/lib/sqlite3/database.rb:69:in ` initialize' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/sqlite3_adapter.rb:13:in `new' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/sqlite3_adapter.rb:13:in `sqlite3_connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:223:in `send' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:223:in `new_connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:245:in `checkout_new_connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:188:in `checkout' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:184:in `loop' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:184:in `checkout' c:/ruby/lib/ruby/1.8/monitor.rb:242:in `synchronize' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:183:in `checkout' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:98:in `connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:326:in `retrieve_connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_specification.rb:123:in `retrieve_connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_specification.rb:115:in `connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/query_ca che.rb:9:in `cache' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/query_ca che.rb:28:in `call' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:361:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/head.rb:9:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/methodoverride.rb:24:in ` call' c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/params _parser.rb:15:in `call' c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/sessio n/cookie_store.rb:93:in `call' c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/failsa fe.rb:26:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in `synchroniz e' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in `call' c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/dispat cher.rb:114:in `call' c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/reload er.rb:34:in `run' c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/dispat cher.rb:108:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/rails/rack/static.rb:31:in `c all' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:46:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in `each' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/rails/rack/log_tailer.rb:17:i n `call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/content_length.rb:13:in ` call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/handler/webrick.rb:50:in `service' c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:104:in `service' c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:65:in `run' c:/ruby/lib/ruby/1.8/webrick/server.rb:173:in `start_thread' c:/ruby/lib/ruby/1.8/webrick/server.rb:162:in `start' c:/ruby/lib/ruby/1.8/webrick/server.rb:162:in `start_thread' c:/ruby/lib/ruby/1.8/webrick/server.rb:95:in `start' c:/ruby/lib/ruby/1.8/webrick/server.rb:92:in `each' c:/ruby/lib/ruby/1.8/webrick/server.rb:92:in `start' c:/ruby/lib/ruby/1.8/webrick/server.rb:23:in `start' c:/ruby/lib/ruby/1.8/webrick/server.rb:82:in `start' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/handler/webrick.rb:14:in `run' c:/ruby/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/commands/server.rb:111 c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_origina l_require' c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require' script/server:3 /!\ FAILSAFE /!\ Sun Jan 31 21:19:39 +0530 2010 Status: 500 Internal Server Error uninitialized constant Encoding c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/depend encies.rb:443:in `load_missing_constant' c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/depend encies.rb:80:in `const_missing' c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/depend encies.rb:92:in `const_missing' c:/ruby/lib/ruby/gems/1.8/gems/sqlite3-0.0.6/lib/sqlite3/encoding.rb:9:in `f ind' c:/ruby/lib/ruby/gems/1.8/gems/sqlite3-0.0.6/lib/sqlite3/database.rb:69:in ` initialize' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/sqlite3_adapter.rb:13:in `new' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/sqlite3_adapter.rb:13:in `sqlite3_connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:223:in `send' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:223:in `new_connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:245:in `checkout_new_connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:188:in `checkout' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:184:in `loop' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:184:in `checkout' c:/ruby/lib/ruby/1.8/monitor.rb:242:in `synchronize' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:183:in `checkout' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:98:in `connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:326:in `retrieve_connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_specification.rb:123:in `retrieve_connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_specification.rb:115:in `connection' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/query_ca che.rb:9:in `cache' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/query_ca che.rb:28:in `call' c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/connecti on_adapters/abstract/connection_pool.rb:361:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/head.rb:9:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/methodoverride.rb:24:in ` call' c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/params _parser.rb:15:in `call' c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/sessio n/cookie_store.rb:93:in `call' c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/failsa fe.rb:26:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in `synchroniz e' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in `call' c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/dispat cher.rb:114:in `call' c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/reload er.rb:34:in `run' c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/dispat cher.rb:108:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/rails/rack/static.rb:31:in `c all' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:46:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in `each' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in `call' c:/ruby/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/rails/rack/log_tailer.rb:17:i n `call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/content_length.rb:13:in ` call' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/handler/webrick.rb:50:in `service' c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:104:in `service' c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:65:in `run' c:/ruby/lib/ruby/1.8/webrick/server.rb:173:in `start_thread' c:/ruby/lib/ruby/1.8/webrick/server.rb:162:in `start' c:/ruby/lib/ruby/1.8/webrick/server.rb:162:in `start_thread' c:/ruby/lib/ruby/1.8/webrick/server.rb:95:in `start' c:/ruby/lib/ruby/1.8/webrick/server.rb:92:in `each' c:/ruby/lib/ruby/1.8/webrick/server.rb:92:in `start' c:/ruby/lib/ruby/1.8/webrick/server.rb:23:in `start' c:/ruby/lib/ruby/1.8/webrick/server.rb:82:in `start' c:/ruby/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/handler/webrick.rb:14:in `run' c:/ruby/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/commands/server.rb:111 c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_origina l_require' c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require' script/server:3

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  • Should I use a collection here?

    - by Eva
    So I have code set up like this: public interface IInterface { public void setField(Object field); } public abstract class AbstractClass extends JPanel implements IInterface { private Object field_; public void setField(Object field) { field_ = field; } } public class ClassA extends AbstractClass { public ClassA() { // unique ClassA constructor stuff } public Dimension getPreferredSize() { return new Dimension(1, 1); } } public class ClassB extends AbstractClass { public ClassB() { // unique ClassB constructor stuff } public Dimension getPreferredSize() { return new Dimension(42, 42); } } public class ConsumerA { public ConsumerA(Collection<AbstractClass> collection) { for (AbstractClass abstractClass : collection) { abstractClass.setField(this); abstractClass.repaint(); } } } All hunky-dory so far, until public class ConsumerB { // Option 1 public ConsumerB(ClassA a, ClassB b) { methodThatOnlyTakesA(a); methodThatOnlyTakesB(b); } // Option 2 public ConsumerB(Collection<AbstractClass> collection) { for (IInterface i : collection) { if (i instanceof ClassA) { methodThatOnlyTakesA((ClassA) i); else if (i instanceof ClassB) { methodThatOnlyTakesB((ClassB) i); } } } } public class UsingOption1 { public static void main(String[] args) { ClassA a = new ClassA(); ClassB b = new ClassB(); Collection<AbstractClass> collection = Arrays.asList(a, b); ConsumerA consumerA = new ConsumerA(collection); ConsumerB consumerB = new ConsumerB(a, b); } } public class UsingOption2 { public static void main(String[] args) { Collection<AbstractClass> collection = Arrays.asList(new ClassA(), new ClassB()); ConsumerA = new ConsumerA(collection); ConsumerB = new ConsumerB(collection); } } With a lot more classes extending AbstractClass, both options get unwieldly. Option1 would make the constructor of ConsumerB really long. Also UsingOption1 would get long too. Option2 would have way more if statements than I feel comfortable with. Is there a viable Option3? If it helps, ClassA and ClassB have all the same methods, they're just implemented differently. Thanks for slogging through my code!

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  • How to easily substitute a Base class

    - by JTom
    Hi, I have the following hierarchy of classes class classOne { virtual void abstractMethod() = 0; }; class classTwo : public classOne { }; class classThree : public classTwo { }; All classOne, classTwo and classThree are abstract classes, and I have another class that is defining the pure virtual methods class classNonAbstract : public classThree { void abstractMethod(); // Couple of new methods void doIt(); void doItToo(); }; And right now I need it differently...I need it like class classNonAbstractOne : public classOne { void abstractMethod(); // Couple of new methods void doIt(); void doItToo(); }; class classNonAbstractTwo : public classTwo { void abstractMethod(); // Couple of new methods void doIt(); void doItToo(); }; and class classNonAbstractThree : public classThree { void abstractMethod(); // Couple of new methods void doIt(); void doItToo(); }; But all the nonAbstract classes have the same new methods, with the same code...and I would like to avoid copying all the methods and it's code to every nonAbstract class. How could I accomplish that? Hopefully it's understandable...

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  • Email function using templates. Includes via ob_start and global vars

    - by Geo
    I have a simple Email() class. It's used to send out emails from my website. <? Email::send($to, $subj, $msg, $options); ?> I also have a bunch of email templates written in plain HTML pierced with a few PHP variables. E.g. /inc/email/templates/account_created.php: <p>Dear <?=$name?>,</p> <p>Thank you for creating an account at <?=$SITE_NAME?>. To login use the link below:</p> <p><a href="https://<?=$SITE_URL?>/account" target="_blank"><?=$SITE_NAME?>/account</a></p> In order to have the PHP vars rendered I had to include the template into my function. But since include does not return the contents but rather just sends it directly to the output, I had to wrap it with the buffer functions: <? abstract class Email { public static function send($to, $subj, $msg, $options = array()) { /* ... */ ob_start(); include '/inc/email/templates/account_created.php'; $msg = ob_get_clean(); /* ... */ } } After that I realized that the PHP vars are not rendered as they are being inside of the function scope, so I had to globalize the variables inside of the template: <? global $SITE_NAME, $SITE_URL, $name; ?> <p>Dear <?=$name?>,</p> ... So the question is whether there is a more elegant solution to this? Mainly I am concerned about my workarounds using ob_start() and global. For some reason that seems to me odd. Or this is pretty much the common practice?

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  • When do instance variables get initialized and values assigned?

    - by AKh
    When doees the instance variable get initialized? Is it after the constructor block is done or before it? Consider this example: public abstract class Parent { public Parent(){ System.out.println("Parent Constructor"); init(); } public void init(){ System.out.println("parent Init()"); } } public class Child extends Parent { private Integer attribute1; private Integer attribute2 = null; public Child(){ super(); System.out.println("Child Constructor"); } public void init(){ System.out.println("Child init()"); super.init(); attribute1 = new Integer(100); attribute2 = new Integer(200); } public void print(){ System.out.println("attribute 1 : " +attribute1); System.out.println("attribute 2 : " +attribute2); } } public class Tester { public static void main(String[] args) { Parent c = new Child(); ((Child)c).print(); } } OUTPUT: Parent Constructor Child init() parent Init() Child Constructor attribute 1 : 100 attribute 2 : null When the memory for the atribute 1 & 2 are allocated in the heap ? Curious to know why is attribute 2 is NULL ? Are there any design flaws?

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  • linear combinations in python/numpy

    - by nmaxwell
    greetings, I'm not sure if this is a dumb question or not. Lets say I have 3 numpy arrays, A1,A2,A3, and 3 floats, c1,c2,c3 and I'd like to evaluate B = A1*c1+ A2*c2+ A3*c3 will numpy compute this as for example, E1 = A1*c1 E2 = A2*c2 E3 = A3*c3 D1 = E1+E2 B = D1+E3 or is it more clever than that? In c++ I had a neat way to abstract this kind of operation. I defined series of general 'LC' template functions, LC for linear combination like: template<class T,class D> void LC( T & R, T & L0,D C0, T & L1,D C1, T & L2,D C2) { R = L0*C0 +L1*C1 +L2*C2; } and then specialized this for various types, so for instance, for an array the code looked like for (int i=0; i<L0.length; i++) R.array[i] = L0.array[i]*C0 + L1.array[i]*C1 + L2.array[i]*C2; thus avoiding having to create new intermediate arrays. This may look messy but it worked really well. I could do something similar in python, but I'm not sure if its nescesary. Thanks in advance for any insight. -nick

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  • Linking a template class using another template class (error LNK2001)

    - by Luís Guilherme
    I implemented the "Strategy" design pattern using an Abstract template class, and two subclasses. Goes like this: template <class T> class Neighbourhood { public: virtual void alter(std::vector<T>& array, int i1, int i2) = 0; }; and template <class T> class Swap : public Neighbourhood<T> { public: virtual void alter(std::vector<T>& array, int i1, int i2); }; There's another subclass, just like this one, and alter is implemented in the cpp file. Ok, fine! Now I declare another method, in another class (including neighbourhood header file, of course), like this: void lSearch(/*parameters*/, Neighbourhood<LotSolutionInformation> nhood); It compiles fine and cleanly. When starting to link, I get the following error: 1>SolverFV.obj : error LNK2001: unresolved external symbol "public: virtual void __thiscall lsc::Neighbourhood<class LotSolutionInformation>::alter(class std::vector<class LotSolutionInformation,class std::allocator<class LotSolutionInformation> > &,int,int)" (?alter@?$Neighbourhood@VLotSolutionInformation@@@lsc@@UAEXAAV?$vector@VLotSolutionInformation@@V?$allocator@VLotSolutionInformation@@@std@@@std@@HH@Z)

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  • Injecting correct object graph using StructureMap in Queue of different Objects

    - by davy
    I have a queuing service that has to inject a different dependency graph depending on the type of object in the queue. I'm using Structure Map. So, if the object in the queue is TypeA the concrete classes for TypeA are used and if it's TypeB, the concrete classes for TypeB are used. I'd like to avoid code in the queue like: if (typeA) { // setup TypeA graph } else if (typeB) { // setup TypeB graph } Within the graph, I also have a generic classes such as an IReader(ISomething, ISpomethingElse) where IReader is generic but needs to inject the correct ISomething and ISomethingElse for the type. ISomething will also have dependencies and so on. Currently I create a TypeA or TypeB object and inject a generic Processor class using StructureMap into it and then pass a factory manually inject a TypeA or TypeB factory into a method like: Processor.Process(new TypeAFactory) // perhaps I should have an abstract factory... However, because the factory then creates the generic IReader mentioned above, I end up manually injecting all the TypeA or TypeB classes fro there on. I hope enough of this makes sense. I am new to StructureMap and was hoping somebody could point me in the right direction here for a flexible and elegant solution. Thanks

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