Search Results

Search found 69357 results on 2775 pages for 'data oriented design'.

Page 1/2775 | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

• Data Quality and Master Data Management Resources

  - by Dejan Sarka

  Many companies or organizations do regular data cleansing. When you cleanse the data, the data quality goes up to some higher level. The data quality level is determined by the amount of work invested in the cleansing. As time passes, the data quality deteriorates, and you need to repeat the cleansing process. If you spend an equal amount of effort as you did with the previous cleansing, you can expect the same level of data quality as you had after the previous cleansing. And then the data quality deteriorates over time again, and the cleansing process starts over and over again. The idea of Data Quality Services is to mitigate the cleansing process. While the amount of time you need to spend on cleansing decreases, you will achieve higher and higher levels of data quality. While cleansing, you learn what types of errors to expect, discover error patterns, find domains of correct values, etc. You don’t throw away this knowledge. You store it and use it to find and correct the same issues automatically during your next cleansing process. The following figure shows this graphically. The idea of master data management, which you can perform with Master Data Services (MDS), is to prevent data quality from deteriorating. Once you reach a particular quality level, the MDS application—together with the defined policies, people, and master data management processes—allow you to maintain this level permanently. This idea is shown in the following picture. OK, now you know what DQS and MDS are about. You can imagine the importance on maintaining the data quality. Here are some resources that help you preparing and executing the data quality (DQ) and master data management (MDM) activities. Books Dejan Sarka and Davide Mauri: Data Quality and Master Data Management with Microsoft SQL Server 2008 R2 – a general introduction to MDM, MDS, and data profiling. Matching explained in depth. Dejan Sarka, Matija Lah and Grega Jerkic: MCTS Self-Paced Training Kit (Exam 70-463): Building Data Warehouses with Microsoft SQL Server 2012 – I wrote quite a few chapters about DQ and MDM, and introduced also SQL Server 2012 DQS. Thomas Redman: Data Quality: The Field Guide – you should start with this book. Thomas Redman is the father of DQ and MDM. Tyler Graham: Microsoft SQL Server 2012 Master Data Services – MDS in depth from a product team mate. Arkady Maydanchik: Data Quality Assessment – data profiling in depth. Tamraparni Dasu, Theodore Johnson: Exploratory Data Mining and Data Cleaning – advanced data profiling with data mining. Forthcoming presentations I am presenting a DQS and MDM seminar at PASS SQL Rally Amsterdam 2013: Wednesday, November 6th, 2013: Enterprise Information Management with SQL Server 2012 – a good kick start to your first DQ and / or MDM project. Courses Data Quality and Master Data Management with SQL Server 2012 – I wrote a 2-day course for SolidQ. If you are interested in this course, which I could also deliver in a shorter seminar way, you can contact your closes SolidQ subsidiary, or, of course, me directly on addresses [email protected] or [email protected]. This course could also complement the existing courseware portfolio of training providers, which are welcome to contact me as well. Start improving the quality of your data now!

  Read the article

• Duplication in parallel inheritance hierarchies

  - by flamingpenguin

  Using an OO language with static typing (like Java), what are good ways to represent the following model invariant without large amounts of duplication. I have two (actually multiple) flavours of the same structure. Each flavour requires its own (unique to that flavour data) on each of the objects within that structure as well as some shared data. But within each instance of the aggregation only objects of one (the same) flavour are allowed. FooContainer can contain FooSources and FooDestinations and associations between the "Foo" objects BarContainer can contain BarSources and BarDestinations and associations between the "Bar" objects interface Container() { List<? extends Source> sources(); List<? extends Destination> destinations(); List<? extends Associations> associations(); } interface FooContainer() extends Container { List<? extends FooSource> sources(); List<? extends FooDestination> destinations(); List<? extends FooAssociations> associations(); } interface BarContainer() extends Container { List<? extends BarSource> sources(); List<? extends BarDestination> destinations(); List<? extends BarAssociations> associations(); } interface Source { String getSourceDetail1(); } interface FooSource extends Source { String getSourceDetail2(); } interface BarSource extends Source { String getSourceDetail3(); } interface Destination { String getDestinationDetail1(); } interface FooDestination extends Destination { String getDestinationDetail2(); } interface BarDestination extends Destination { String getDestinationDetail3(); } interface Association { Source getSource(); Destination getDestination(); } interface FooAssociation extends Association { FooSource getSource(); FooDestination getDestination(); String getFooAssociationDetail(); } interface BarAssociation extends Association { BarSource getSource(); BarDestination getDestination(); String getBarAssociationDetail(); }

  Read the article

• design pattern advice: graph -> computation

  - by csetzkorn

  I have a domain model, persisted in a database, which represents a graph. A graph consists of nodes (e.g. NodeTypeA, NodeTypeB) which are connected via branches. The two generic elements (nodes and branches will have properties). A graph will be sent to a computation engine. To perform computations the engine has to be initialised like so (simplified pseudo code): Engine Engine = new Engine() ; Object ID1 = Engine.AddNodeTypeA(TypeA.Property1, TypeA.Property2, …, TypeA.Propertyn); Object ID2 = Engine.AddNodeTypeB(TypeB.Property1, TypeB.Property2, …, TypeB.Propertyn); Engine.AddBranch(ID1,ID2); Finally the computation is performed like this: Engine.DoSomeComputation(); I am just wondering, if there are any relevant design patterns out there, which help to achieve the above using good design principles. I hope this makes sense. Any feedback would be very much appreciated.

  Read the article

• Good design cannot be over-design

  - by ??? Shengyuan Lu

  Many engineers intend to design software to build "flexible" system in which many design patterns and interfaces there. Eventually too many interfaces and complex inheritances mess up the system. In most cases I think the improper design caused the mess, rather than not over-design. If design is reasonable, it's hard to be over. Alternatively, If we don't have enough skill to achieve flexible design, we choose to plain and practical design. What's your opinion about my understanding?

  Read the article

• What is difference between Interaction design, Visual Design, Web design, UX design, UI design, UI d

  - by rajakvk

  What is difference between Interaction design, Visual Design, Web design, UX design, UI design, UI development? BTB, link found below answered for UI Vs UX. http://stackoverflow.com/questions/1334496/difference-between-ui-and-ux

  Read the article

• Requesting feedback on my OO design

  - by Prog

  I'm working on an application that creates music by itself. I'm seeking feedback for my OO design so far. This question will focus on one part of the program. The application produces Tune objects, that are the final musical products. Tune is an abstract class with an abstract method play. It has two subclasses: SimpleTune and StructuredTune. SimpleTune owns a Melody and a Progression (chord sequence). It's play implementation plays these two objects simultaneously. StructuredTune owns two Tune instances. It's own play plays the two Tunes one after the other according to a pattern (currently only ABAB). Melody is an abstract class with an abstract play method. It has two subclasses: SimpleMelody and StructuredMelody. SimpleMelody is composed of an array of notes. Invoking play on it plays these notes one after the other. StructuredMelody is composed of an array of Melody objects. Invoking play on it plays these Melodyies one after the other. I think you're starting to see the pattern. Progression is also an abstract class with a play method and two subclasses: SimpleProgression and StructuredProgression, each composed differently and played differently. SimpleProgression owns an array of chords and plays them sequentially. StructuredProgression owns an array of Progressions and it's play implementation plays them sequentially. Every class has a corresponding Generator class. Tune, Melody and Progression are matched with corresponding abstract TuneGenerator, MelodyGenerator and ProgressionGenerator classes, each with an abstract generate method. For example MelodyGenerator defines an abstract Melody generate method. Each of the generators has two subclasses, Simple and Structured. So for example MelodyGenerator has a subclasses SimpleMelodyGenerator, with an implementation of generate that returns a SimpleMelody. (It's important to note that the generate methods encapsulate complex algorithms. They are more than mere factory method. For example SimpleProgressionGenerator.generate() implements an algorithm to compose a series of Chord objects, which are used to instantiate the returned SimpleProgression). Every Structured generator uses another generator internally. It is a Simple generator be default, but in special cases may be a Structured generator. Parts of this design are meant to allow the end-user through the GUI to choose what kind of music is to be created. For example the user can choose between a "simple tune" (SimpleTuneGenerator) and a "full tune" (StructuredTuneGenerator). Other parts of the system aren't subject to direct user-control. What do you think of this design from an OOD perspective? What potential problems do you see with this design? Please share with me your criticism, I'm here to learn. Apart from this, a more specific question: the "every class has a corresponding Generator class" part feels very wrong. However I'm not sure how I could design this differently and achieve the same flexibility. Any ideas?

  Read the article

• Is this proper OO design for C++?

  - by user121917

  I recently took a software processes course and this is my first time attempting OO design on my own. I am trying to follow OO design principles and C++ conventions. I attempted and gave up on MVC for this application, but I am trying to "decouple" my classes such that they can be easily unit-tested and so that I can easily change the GUI library used and/or the target OS. At this time, I have finished designing classes but have not yet started implementing methods. The function of the software is to log all packets sent and received, and display them on the screen (like WireShark, but for one local process only). The software accomplishes this by hooking the send() and recv() functions in winsock32.dll, or some other pair of analogous functions depending on what the intended Target is. The hooks add packets to SendPacketList/RecvPacketList. The GuiLogic class starts a thread which checks for new packets. When new packets are found, it utilizes the PacketFilter class to determine the formatting for the new packet, and then sends it to MainWindow, a native win32 window (with intent to later port to Qt).1 Full size image of UML class diagram Here are my classes in skeleton/header form (this is my actual code): class PacketModel { protected: std::vector<byte> data; int id; public: PacketModel(); PacketModel(byte* data, unsigned int size); PacketModel(int id, byte* data, unsigned int size); int GetLen(); bool IsValid(); //len >= sizeof(opcode_t) opcode_t GetOpcode(); byte* GetData(); //returns &(data[0]) bool GetData(byte* outdata, int maxlen); void SetData(byte* pdata, int len); int GetId(); void SetId(int id); bool ParseData(char* instr); bool StringRepr(char* outstr); byte& operator[] (const int index); }; class SendPacket : public PacketModel { protected: byte* returnAddy; public: byte* GetReturnAddy(); void SetReturnAddy(byte* addy); }; class RecvPacket : public PacketModel { protected: byte* callAddy; public: byte* GetCallAddy(); void SetCallAddy(byte* addy); }; //problem: packets may be added to list at any time by any number of threads //solution: critical section associated with each packet list class Synch { public: void Enter(); void Leave(); }; template<class PacketType> class PacketList { private: static const int MAX_STORED_PACKETS = 1000; public: static const int DEFAULT_SHOWN_PACKETS = 100; private: vector<PacketType> list; Synch synch; //wrapper for critical section public: void AddPacket(PacketType* packet); PacketType* GetPacket(int id); int TotalPackets(); }; class SendPacketList : PacketList<SendPacket> { }; class RecvPacketList : PacketList<RecvPacket> { }; class Target //one socket { bool Send(SendPacket* packet); bool Inject(RecvPacket* packet); bool InitSendHook(SendPacketList* sendList); bool InitRecvHook(RecvPacketList* recvList); }; class FilterModel { private: opcode_t opcode; int colorID; bool bFilter; char name[41]; }; class FilterFile { private: FilterModel filter; public: void Save(); void Load(); FilterModel* GetFilter(opcode_t opcode); }; class PacketFilter { private: FilterFile filters; public: bool IsFiltered(opcode_t opcode); bool GetName(opcode_t opcode, char* namestr); //return false if name does not exist COLORREF GetColor(opcode_t opcode); //return default color if no custom color }; class GuiLogic { private: SendPacketList sendList; RecvPacketList recvList; PacketFilter packetFilter; void GetPacketRepr(PacketModel* packet); void ReadNew(); void AddToWindow(); public: void Refresh(); //called from thread void GetPacketInfo(int id); //called from MainWindow }; I'm looking for a general review of my OO design, use of UML, and use of C++ features. I especially just want to know if I'm doing anything considerably wrong. From what I've read, design review is on-topic for this site (and off-topic for the Code Review site). Any sort of feedback is greatly appreciated. Thanks for reading this.

  Read the article

• Object oriented wrapper around a dll

  - by Tom Davies

  So, I'm writing a C# managed wrapper around a native dll. The dll contains several hundred functions. In most cases, the first argument to each function is an opaque handle to a type internal to the dll. So, an obvious starting point for defining some classes in the wrapper would be to define classes corresponding to each of these opaque types, with each instance holding and managing the opaque handle (passed to its constructor) Things are a little awkward when dealing with callbacks from the dll. Naturally, the callback handlers in my wrapper have to be static, but the callbacks arguments invariable contain an opaque handle. In order to get from the static callback back to an object instance, I've created a static dictionary in each class, associating handles with class instances. In the constructor of each class, an entry is put into the dictionary, and this entry is then removed in the Destructors. When I receive a callback, I can then consult the dictionary to retrieve the class instance corresponding to the opaque reference. Are there any obvious flaws to this? Something that seems to be a problem is that the existence static dictionary means that the garbage collector will not act on my class instances that are otherwise unreachable. As they are never garbage collected, they never get removed from the dictionary, so the dictionary grows. It seems I might have to manually dispose of my objects, which is something absolutely would like to avoid. Can anyone suggest a good design that allows me to avoid having to do this?

  Read the article

• Loose Coupling in Object Oriented Design

  - by m3th0dman

  I am trying to learn GRASP and I found this explained (here on page 3) about Low Coupling and I was very surprised when I found this: Consider the method addTrack for an Album class, two possible methods are: addTrack( Track t ) and addTrack( int no, String title, double duration ) Which method reduces coupling? The second one does, since the class using the Album class does not have to know a Track class. In general, parameters to methods should use base types (int, char ...) and classes from the java.* packages. I tend to diasgree with this; I believe addTrack(Track t) is better than addTrack(int no, String title, double duration) due to various reasons: It is always better for a method to as fewer parameters as possible (according to Uncle Bob's Clean Code none or one preferably, 2 in some cases and 3 in special cases; more than 3 needs refactoring - these are of course recommendations not holly rules). If addTrack is a method of an interface, and the requirements need that a Track should have more information (say year or genre) then the interface needs to be changed and so that the method should supports another parameter. Encapsulation is broke; if addTrack is in an interface, then it should not know the internals of the Track. It is actually more coupled in the second way, with many parameters. Suppose the no parameter needs to be changed from int to long because there are more than MAX_INT tracks (or for whatever reason); then both the Track and the method need to be changed while if the method would be addTrack(Track track) only the Track would be changed. All the 4 arguments are actually connected with each other, and some of them are consequences from others. Which approach is better?

  Read the article

• Refactoring in domain driven design

  - by Andrew Whitaker

  I've just started working on a project and we're using domain-driven design (as defined by Eric Evans in Domain-Driven Design: Tackling Complexity in the Heart of Software. I believe that our project is certainly a candidate for this design pattern as Evans describes it in his book. I'm struggling with the idea of constantly refactoring. I know refactoring is a necessity in any project and will happen inevitably as the software changes. However, in my experience, refactoring occurs when the needs of the development team change, not as understanding of the domain changes ("refactoring to greater insight" as Evans calls it). I'm most concerned with breakthroughs in understanding of the domain model. I understand making small changes, but what if a large change in the model is necessary? What's an effective way of convincing yourself (and others) you should refactor after you obtain a clearer domain model? After all, refactoring to improve code organization or performance could be completely separate from how expressive in terms of the ubiquitous language code is. Sometimes it just seems like there's not enough time to refactor. Luckily, SCRUM lends it self to refactoring. The iterative nature of SCRUM makes it easy to build a small piece and change and it. But over time that piece will get larger and what if you have a breakthrough after that piece is so large that it will be too difficult to change? Has anyone worked on a project employing domain-driven design? If so, it would be great to get some insight on this one. I'd especially like to hear some success stories, since DDD seems very difficult to get right. Thanks!

  Read the article

• Document-oriented vs Column-oriented database fit

  - by user1007922

  I have a data-intensive application that desperately needs a database make-over. The general data model: There are records with RIDs, grouped together by group IDs (GID). The records have arbitrary data fields, (maybe 5-15) with a few of them mandatory and the rest optional, and thus sparse. The general use model: There are LOTS and LOTS of Writes. Millions to Billions of records are stored. Very often, they are associated with new GIDs, but sometimes, they are associated with existing GIDs. There aren't as many reads, but when they happen, they need to be pretty fast or at least constant speed regardless of the database size. And when the reads happen, it will need to retrieve all the records/RIDs with a certain GID. I don't have a need to search by the record field values. Primarily, I will need to query by the GID and maybe RID. What database implementation should I use? I did some initial research between document-oriented and column-oriented databases and it seems the document-oriented ones are a good fit, model-wise. I could store all the records together under the same document key using the GID. But I don't really have any use for their ability to search the document contents itself. I like the simplicity and scalability of column-oriented databases like Cassandra, but how should I model my data in this paradigm for optimal performance? Should my key be the GID and should I create a column for each record/RID? (there maybe thousands or hundreds of thousands of records in a group/GID). Or should my key be the RID and ensure each row has a column for the GID value? What results in faster writes and reads under this model?

  Read the article

• How do we keep dependent data structures up to date?

  - by Geo

  Suppose you have a parse tree, an abstract syntax tree, and a control flow graph, each one logically derived from the one before. In principle it is easy to construct each graph given the parse tree, but how can we manage the complexity of updating the graphs when the parse tree is modified? We know exactly how the tree has been modified, but how can the change be propagated to the other trees in a way that doesn't become difficult to manage? Naturally the dependent graph can be updated by simply reconstructing it from scratch every time the first graph changes, but then there would be no way of knowing the details of the changes in the dependent graph. I currently have four ways to attempt to solve this problem, but each one has difficulties. Nodes of the dependent tree each observe the relevant nodes of the original tree, updating themselves and the observer lists of original tree nodes as necessary. The conceptual complexity of this can become daunting. Each node of the original tree has a list of the dependent tree nodes that specifically depend upon it, and when the node changes it sets a flag on the dependent nodes to mark them as dirty, including the parents of the dependent nodes all the way down to the root. After each change we run an algorithm that is much like the algorithm for constructing the dependent graph from scratch, but it skips over any clean node and reconstructs each dirty node, keeping track of whether the reconstructed node is actually different from the dirty node. This can also get tricky. We can represent the logical connection between the original graph and the dependent graph as a data structure, like a list of constraints, perhaps designed using a declarative language. When the original graph changes we need only scan the list to discover which constraints are violated and how the dependent tree needs to change to correct the violation, all encoded as data. We can reconstruct the dependent graph from scratch as though there were no existing dependent graph, and then compare the existing graph and the new graph to discover how it has changed. I'm sure this is the easiest way because I know there are algorithms available for detecting differences, but they are all quite computationally expensive and in principle it seems unnecessary so I'm deliberately avoiding this option. What is the right way to deal with these sorts of problems? Surely there must be a design pattern that makes this whole thing almost easy. It would be nice to have a good solution for every problem of this general description. Does this class of problem have a name?

  Read the article

• Object oriented design importance

  - by user5507

  I started studying Object Oriented Design and Modelling using the this book by James Rumbaugh. It uses a tool called Object Modeling Technique (OMT). I have certain newbie questions. I searched the net, but couldn't get answers The book is pretty old. Don't know why the school told me to learn this. I know OMT is a predecessor of the Unified Modeling Language (UML). So its a waste? Whether the concepts change very much when we move from OMT to UML? I know OMT has Object, Dynamic and Functional Model. Wikipedia says UML is compatible with OMT and UML is a model too. As per wikipedia the UML models are Static and Dynamic and they are represented by different diagrams like class, object, activity, sequence..... I couldn't find the equivalence of this in OMT. I read that there are many object oriented development methods like OMT, Booch,.... Which one is used by Industry ? Where could I get a comparison of different Object oriented development methods?

  Read the article

• Recommened design pattern to handle multiple compression algorithms for a class hierarchy

  - by sgorozco

  For all you OOD experts. What would be the recommended way to model the following scenario? I have a certain class hierarchy similar to the following one: class Base { ... } class Derived1 : Base { ... } class Derived2 : Base { ... } ... Next, I would like to implement different compression/decompression engines for this hierarchy. (I already have code for several strategies that best handle different cases, like file compression, network stream compression, legacy system compression, etc.) I would like the compression strategy to be pluggable and chosen at runtime, however I'm not sure how to handle the class hierarchy. Currently I have a tighly-coupled design that looks like this: interface ICompressor { byte[] Compress(Base instance); } class Strategy1Compressor : ICompressor { byte[] Compress(Base instance) { // Common compression guts for Base class ... // if( instance is Derived1 ) { // Compression guts for Derived1 class } if( instance is Derived2 ) { // Compression guts for Derived2 class } // Additional compression logic to handle other class derivations ... } } As it is, whenever I add a new derived class inheriting from Base, I would have to modify all compression strategies to take into account this new class. Is there a design pattern that allows me to decouple this, and allow me to easily introduce more classes to the Base hierarchy and/or additional compression strategies?

  Read the article

• How do I handle priority and propagation in an event system?

  - by Peeter

  Lets say I have a simple event system with the following syntax: object = new Object(); object.bind("my_trigger", function() { print "hello"; }); object.bind("my_trigger", function() { print "hello2"; }); object.trigger("my_trigger"); How could I make sure hello2 is printed out first (I do not want my code to depend on which order the events are binded). Ontop of that, how would I prevent my events from propagating (e.g. I want to stop every other event from being executed)

  Read the article

• Taking Object Oriented development to the next level

  - by Songo

  Can you mention some advanced OO topics or concepts that one should be aware of? I have been a developer for 2 years now and currently aiming for a certain company that requires a web developer with a minimum experience of 3 years. I imagine the interview will have the basic object oriented topics like (Abstraction, Polymorphism, Inheritance, Design patterns, UML, Databases and ORMs, SOLID principles, DRY principle, ...etc) I have these topics covered, but what I'm looking forward to is bringing up topics such as Efferent Coupling, Afferent Coupling, Instability, The law of Demeter, ...etc. Till few days ago I never knew such concepts existed (maybe because I'm a communication engineer basically not a CS graduate.) Can you please recommend some more advanced topics concerning object oriented programming?

  Read the article

• Looking for some OO design advice

  - by Andrew Stephens

  I'm developing an app that will be used to open and close valves in an industrial environment, and was thinking of something simple like this:- public static void ValveController { public static void OpenValve(string valveName) { // Implementation to open the valve } public static void CloseValve(string valveName) { // Implementation to close the valve } } (The implementation would write a few bytes of data to the serial port to control the valve - an "address" derived from the valve name, and either a "1" or "0" to open or close the valve). Another dev asked whether we should instead create a separate class for each physical valve, of which there are dozens. I agree it would be nicer to write code like PlasmaValve.Open() rather than ValveController.OpenValve("plasma"), but is this overkill? Also, I was wondering how best to tackle the design with a couple of hypothetical future requirements in mind:- We are asked to support a new type of valve requiring different values to open and close it (not 0 and 1). We are asked to support a valve that can be set to any position from 0-100, rather than simply "open" or "closed". Normally I would use inheritance for this kind of thing, but I've recently started to get my head around "composition over inheritance" and wonder if there is a slicker solution to be had using composition?

  Read the article

• C# vector class - Interpolation design decision

  - by Benjamin

  Currently I'm working on a vector class in C# and now I'm coming to the point, where I've to figure out, how i want to implement the functions for interpolation between two vectors. At first I came up with implementing the functions directly into the vector class... public class Vector3D { public static Vector3D LinearInterpolate(Vector3D vector1, Vector3D vector2, double factor) { ... } public Vector3D LinearInterpolate(Vector3D other, double factor { ... } } (I always offer both: a static method with two vectors as parameters and one non-static, with only one vector as parameter) ...but then I got the idea to use extension methods (defined in a seperate class called "Interpolation" for example), since interpolation isn't really a thing only available for vectors. So this could be another solution: public class Vector3D { ... } public static class Interpolation { public static Vector3D LinearInterpolate(this Vector3D vector, Vector3D other, double factor) { ... } } So here an example how you'd use the different possibilities: { var vec1 = new Vector3D(5, 3, 1); var vec2 = new Vector3D(4, 2, 0); Vector3D vec3; vec3 = vec1.LinearInterpolate(vec2, 0.5); //1 vec3 = Vector3D.LinearInterpolate(vec1, vec2, 0.5); //2 //or with extension-methods vec3 = vec1.LinearInterpolate(vec2, 0.5); //3 (same as 1) vec3 = Interpolation.LinearInterpolation(vec1, vec2, 0.5); //4 } So I really don't know which design is better. Also I don't know if there's an ultimate rule for things like this or if it's just about what someone personally prefers. But I really would like to hear your opinions, what's better (and if possible why ).

  Read the article

• design for supporting entities with images

  - by brainydexter

  I have multiple entities like Hotels, Destination Cities etc which can contain images. The way I have my system setup right now is, I think of all the images belonging to this universal set (a table in the DB contains filePaths to all the images). When I have to add an image to an entity, I see if the entity exists in this universal set of images. If it exists, attach the reference to this image, else create a new image. E.g.: class ImageEntityHibernateDAO { public void addImageToEntity(IContainImage entity, String filePath, String title, String altText) { ImageEntity image = this.getImage(filePath); if (image == null) image = new ImageEntity(filePath, title, altText); getSession().beginTransaction(); entity.getImages().add(image); getSession().getTransaction().commit(); } } My question is: Earlier I had to write this code for each entity (and each entity would have a Set collection). So, instead of re-writing the same code, I created the following interface: public interface IContainImage { Set<ImageEntity> getImages(); } Entities which have image collections also implements IContainImage interface. Now, for any entity that needs to support adding Image functionality, all I have to invoke from the DAO looks something like this: // in DestinationDAO::addImageToDestination { imageDao.addImageToEntity(destination, imageFileName, imageTitle, imageAltText); // in HotelDAO::addImageToHotel { imageDao.addImageToEntity(hotel, imageFileName, imageTitle, imageAltText); It'd be great help if someone can provide me some critique on this design ? Are there any serious flaws that I'm not seeing right away ?

  Read the article

• PHP Aspect Oriented Design

  - by Devin Dixon

  This is a continuation of this Code Review question. What was taken away from that post, and other aspect oriented design is it is hard to debug. To counter that, I implemented the ability to turn tracing of the design patterns on. Turning trace on works like: //This can be added anywhere in the code Run::setAdapterTrace(true); Run::setFilterTrace(true); Run::setObserverTrace(true); //Execute the functon echo Run::goForARun(8); In the actual log with the trace turned on, it outputs like so: adapter 2012-02-12 21:46:19 {"type":"closure","object":"static","call_class":"\/public_html\/examples\/design\/ClosureDesigns.php","class":"Run","method":"goForARun","call_method":"goForARun","trace":"Run::goForARun","start_line":68,"end_line":70} filter 2012-02-12 22:05:15 {"type":"closure","event":"return","object":"static","class":"run_filter","method":"\/home\/prodigyview\/public_html\/examples\/design\/ClosureDesigns.php","trace":"Run::goForARun","start_line":51,"end_line":58} observer 2012-02-12 22:05:15 {"type":"closure","object":"static","class":"run_observer","method":"\/home\/prodigyview\/public_html\/public\/examples\/design\/ClosureDesigns.php","trace":"Run::goForARun","start_line":61,"end_line":63} When the information is broken down, the data translates to: Called by an adapter or filter or observer The function called was a closure The location of the closure Class:method the adapter was implemented on The Trace of where the method was called from Start Line and End Line The code has been proven to work in production environments and features various examples of to implement, so the proof of concept is there. It is not DI and accomplishes things that DI cannot. I wouldn't call the code boilerplate but I would call it bloated. In summary, the weaknesses are bloated code and a learning curve in exchange for aspect oriented functionality. Beyond the normal fear of something new and different, what are other weakness in this implementation of aspect oriented design, if any? PS: More examples of AOP here: https://github.com/ProdigyView/ProdigyView/tree/master/examples/design

  Read the article

• Data classes: getters and setters or different method design

  - by Frog

  I've been trying to design an interface for a data class I'm writing. This class stores styles for characters, for example whether the character is bold, italic or underlined. But also the font-size and the font-family. So it has different types of member variables. The easiest way to implement this would be to add getters and setters for every member variable, but this just feels wrong to me. It feels way more logical (and more OOP) to call style.format(BOLD, true) instead of style.setBold(true). So to use logical methods insteads of getters/setters. But I am facing two problems while implementing these methods: I would need a big switch statement with all member variables, since you can't access a variable by the contents of a string in C++. Moreover, you can't overload by return type, which means you can't write one getter like style.getFormatting(BOLD) (I know there are some tricks to do this, but these don't allow for parameters, which I would obviously need). However, if I would implement getters and setters, there are also issues. I would have to duplicate quite some code because styles can also have a parent styles, which means the getters have to look not only at the member variables of this style, but also at the variables of the parent styles. Because I wasn't able to figure out how to do this, I decided to ask a question a couple of weeks ago. See Object Oriented Programming: getters/setters or logical names. But in that question I didn't stress it would be just a data object and that I'm not making a text rendering engine, which was the reason one of the people that answered suggested I ask another question while making that clear (because his solution, the decorator pattern, isn't suitable for my problem). So please note that I'm not creating my own text rendering engine, I just use these classes to store data. Because I still haven't been able to find a solution to this problem I'd like to ask this question again: how would you design a styles class like this? And why would you do that? Thanks on forehand!

  Read the article

• Learning how to design knowledge and data flow [closed]

  - by max

  In designing software, I spend a lot of time deciding how the knowledge (algorithms / business logic) and data should be allocated between different entities; that is, which object should know what. I am asking for advice about books, articles, presentations, classes, or other resources that would help me learn how to do it better. I code primarily in Python, but my question is not really language-specific; even if some of the insights I learn don't work in Python, that's fine. I'll give a couple examples to clarify what I mean. Example 1 I want to perform some computation. As a user, I will need to provide parameters to do the computation. I can have all those parameters sent to the "main" object, which then uses them to create other objects as needed. Or I can create one "main" object, as well as several additional objects; the additional objects would then be sent to the "main" object as parameters. What factors should I consider to make this choice? Example 2 Let's say I have a few objects of type A that can perform a certain computation. The main computation often involves using an object of type B that performs some interim computation. I can either "teach" A instances what exact parameters to pass to B instances (i.e., make B "dumb"); or I can "teach" B instances to figure out what needs to be done when looking at an A instance (i.e., make B "smart"). What should I think about when I'm making this choice?

  Read the article

• Design suggestions needed to create a MathBuilder framework

  - by Darf Zon

  Let explain what I'm trying to create. I'm creating a framework, the idea is to provide base classes to generate a math problem. Why do I need this framework? Because at first time, I realized when I create a new math problem I always do the same steps. Configuration settings such range numbers. For example if I'm developing multiplications, in beginner level only generate the first number between 2-5 or in advanced level, the first number will be between 6- 9, for example. Generate problem method. All the time I need to invoke a method like this to generate the problem. This one receives the configuration settings and generate the number according to them. And generate the object with the respective data. Validate the problem. Sometimes the problem generated is not valid. For example, supposed I'm creating fractions in most simplified, if I receive 2/4, the program should detect that this is not valid and must generate another like this one, 1/4. Load the view. All of them, have a custom view (please watch below the images). All of the problems must know how to CHECK if the user result is correct. All of this problems has answers. Some of them just require one answer, anothers may require more than one, so I guess a way to maintain flexibility to the developer has all the answers he wanna used. At the beginning I started using PRISM. Generate modules for each math problem was the idea and load it in the main system. I guess are the most important things of this idea. Let me showing some problems which I create in a WPF standalone program. Here I have a math problem about areas. When I generate the problem a set to the view the object and it draw it. In beginner level, I set in the configuration settings that just load square types. But in advance level, can load triangles and squares randomly. In this another, generate a binary problem like addition, subtraction, multiplication or division. Above just generate a single problem. The idea of this is to show a test o quiz, I mean get a worksheet (this I call as a collection of problems) where the user can answer it. I hope gets the idea with my ugly drawing. How to load this math problems? As I said above, I started using PRISM, and each module contains a math problem kind. This is a snapshot of my first demo. Below show the modules loaded, and center the respective configurations or levels. Until momment, I have no idea to start creating this software. I just know that I need a question | problem class, response class, user class. But I get lost about what properties should have to contain in it. Please give a little hand of this framework. I put much effort on this question, so if any isn't clear, let me know to clarify it.

  Read the article

• Starting to create a MathBuilder framework, help to start creating the design

  - by Darf Zon

  Let explain what I'm trying to create. I'm creating a framework, the idea is to provide base classes to generate a math problem. Why do I need this framework? Because at first time, I realized when I create a new math problem I always do the same steps. Configuration settings such range numbers. For example if I'm developing multiplications, in beginner level only generate the first number between 2-5 or in advanced level, the first number will be between 6- 9, for example. Generate problem method. All the time I need to invoke a method like this to generate the problem. This one receives the configuration settings and generate the number according to them. And generate the object with the respective data. Validate the problem. Sometimes the problem generated is not valid. For example, supposed I'm creating fractions in most simplified, if I receive 2/4, the program should detect that this is not valid and must generate another like this one, 1/4. Load the view. All of them, have a custom view (please watch below the images). All of the problems must know how to CHECK if the user result is correct. All of this problems has answers. Some of them just require one answer, anothers may require more than one, so I guess a way to maintain flexibility to the developer has all the answers he wanna used. At the beginning I started using PRISM. Generate modules for each math problem was the idea and load it in the main system. I guess are the most important things of this idea. Let me showing some problems which I create in a WPF standalone program. Here I have a math problem about areas. When I generate the problem a set to the view the object and it draw it. In beginner level, I set in the configuration settings that just load square types. But in advance level, can load triangles and squares randomly. In this another, generate a binary problem like addition, subtraction, multiplication or division. Above just generate a single problem. The idea of this is to show a test o quiz, I mean get a worksheet (this I call as a collection of problems) where the user can answer it. I hope gets the idea with my ugly drawing. How to load this math problems? As I said above, I started using PRISM, and each module contains a math problem kind. This is a snapshot of my first demo. Below show the modules loaded, and center the respective configurations or levels. Until momment, I have no idea to start creating this software. I just know that I need a question | problem class, response class, user class. But I get lost about what properties should have to contain in it. Please give a little hand of this framework. I put much effort on this question, so if any isn't clear, let me know to clarify it.

  Read the article

• High-Level Application Architecture Question

  - by Jesse Bunch

  So I'm really wanting to improve how I architect the software I code. I want to focus on maintainability and clean code. As you might guess, I've been reading a lot of resources on this topic and all it's doing is making it harder for me to settle on an architecture because I can never tell if my design is the one that the more experienced programmer would've chosen. So I have these requirements: I should connect to one vendor and download form submissions from their API. We'll call them the CompanyA. I should then map those submissions to a schema fit for submitting to another vendor for integration with the email service provider. We'll call them the CompanyB. I should then submit those responses to the ESP (CompanyB) and then instruct the ESP to send that submitter an email. So basically, I'm copying data from one web service to another and then performing an action at the latter web service. I've identified a couple high-level services: The service that downloads data from CompanyA. I called this the CompanyAIntegrator. The service that submits the data to CompanyB. I called this CompanyBIntegrator. So my questions are these: Is this a good design? I've tried to separate the concerns and am planning to use the facade pattern to make the integrators interchangeable if the vendors change in the future. Are my naming conventions accurate and meaningful to you (who knows nothing specific of the project)? Now that I have these services, where should I do the work of taking output from the CompanyAIntegrator and getting it in the format for input to the CompanyBIntegrator? Is this OK to be done in main()? Do you have any general pointers on how you'd code something like this? I imagine this scenario is common to us engineers---especially those working in agencies. Thanks for any help you can give. Learning how to architect well is really mind-cluttering.

  Read the article

1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >