Search Results

Search found 30072 results on 1203 pages for 'website design'.

Page 22/1203 | < Previous Page | 18 19 20 21 22 23 24 25 26 27 28 29  | Next Page >

  • USE case to Class Diagram - How do I?

    - by 01010011
    Hi, I would like your guidance on how to create classes and their relationships (generalization, association, aggregation and composition) accurately from my USE case diagram (please see below). I am trying to create this class diagram so I can use it to create a simple online PHP application that allows the user to register an account, login and logout, and store, search and retrieve data from a MySQL database. Are my classes correct? Or should I create more classes? And if so, what classes are missing? What relationships should I use when connecting the register, login, logout, search_database and add_to_database to the users? I'm new to design patterns and UML class diagrams but from my understanding, the association relationship relates one object with another object; the aggregation relationship is a special kind of association that allows "a part" to belong to more than one "whole" (e.g. a credit card and its PIN - the PIN class can also be used in a debit card class); and a composition relationship is a special form of aggregation that allows each part to belong to only one whole at a time. I feel like I have left out some classes or something because I just can't seem to find the relationships from my understanding of relationships. Any assistance will be really appreciated. Thanks in advance. USE CASE DIAGRAM CLASS DIAGRAM

    Read the article

  • Separation of domain and ui layer in a composite

    - by hansmaad
    Hi all, i'm wondering if there is a pattern how to separate the domain logic of a class from the ui responsibilities of the objects in the domain layer. Example: // Domain classes interface MachinePart { CalculateX(in, out) // Where do we put these: // Draw(Screen) ?? // ShowProperties(View) ?? // ... } class Assembly : MachinePart { CalculateX(in, out) subParts } class Pipe : MachinePart { CalculateX(in, out) length, diamater... } There is an application that calculates the value X for machines assembled from many machine parts. The assembly is loaded from a file representation and is designed as a composite. Each concrete part class stores some data to implement the CalculateX(in,out) method to simulate behaviour of the whole assembly. The application runs well but without GUI. To increase the usability a GUi should be developed on top of the existing implementation (changes to the existing code are allowed). The GUI should show a schematic graphical representation of the assembly and provide part specific dialogs to edit several parameters. To achieve these goals the application needs new functionality for each machine part to draw a schematic representation on the screen, show a property dialog and other things not related to the domain of machine simulation. I can think of some different solutions to implement a Draw(Screen) functionality for each part but i am not happy with each of them. First i could add a Draw(Screen) method to the MachinePart interface but this would mix-up domain code with ui code and i had to add a lot of functionality to each machine part class what makes my domain model hard to read and hard to understand. Another "simple" solution is to make all parts visitable and implement ui code in visitors but Visitor does not belong to my favorite patterns. I could derive UI variants from each machine part class to add the UI implementation there but i had to check if each part class is suited for inheritance and had to be careful on changes to the base classes. My currently favorite design is to create a parallel composite hierarchy where each component stores data to define a machine part, has implementation for UI methods and a factory method which creates instances of the corresponding domain classes, so that i can "convert" a UI assembly to a domain assembly. But there are problems to go back from the created domain hierarchy to the UI hierarchy for showing calculation results in the drawing for example (imagine some parts store some values during the calculation i want to show in the schematic representation after the simluation). Maybe there are some proven patterns for such problems?

    Read the article

  • Website Upgrade - Avoid Downtime

    - by nolan.sipos
    I have been requested to investigate how I can reduce the downtime of our website upgrades. We maintain a DNN site with both public facing pages and member only pages. The member only pages are directly linked to our core application database while the public pages are not. Our current process is to redirect website users as soon as the upgrade process begins, which includes Backup of the Prod DB Update Prod DB Update Executables (Application) Upgrade Website Application (If this requires an update) Install Dependencies Upgrade sub systems like communication engine and payment broker Update various configuration files Perform testing of systems Restart all services Allow access to site This process can take from 2 to 8 hours depending on upgrade required, scripts to be run, size of database and number or portals. My initial thoughts are to restrict users to read only pages and any update pages would be unavailable. Could anyone please offer suggestions as to the best practices for what I would think to be a common problem so that we can reduce this down time and if we need infrastructure changes, I can put this to our technical department.

    Read the article

  • What is the greatest design flaw you have faced in any programming language?

    - by Anto
    All programming languages are having their design flaws simply because not a single language can be perfect, just as with most (all?) other things. That aside, which design fault in a programming language has annoyed you the most through your history as a programmer? Note that if a language is "bad" just because it isn't designed for a specific thing isn't a design flaw, but a feature of design, so don't list such annoyances of languages. If a language is illsuited for what it is designed for, that is of course a flaw in the design. Implementation specific things and under the hood things do not count either.

    Read the article

  • Development: SDK for Social Net

    - by loldop
    I have a task: development sdk for social networking service like facebook, twitter and etc. At now i'm developing facebook-extension-sdk which based on facebook-ios-sdk 3.0. But not all social networking services have good sdks. And all time i improved my facebook-extension-sdk, when i see ugly code :( Please, advise me good techniques to development these sdks (like design-patterns or your own experience or good books/sites). Thanks!

    Read the article

  • How do I write code that doesn't suck? [closed]

    - by Afnan
    My friends and I would like to write a C# desktop application, and would like some guidance on how to make sure the code base is professional and well-kept. Should we use classes or interfaces for our inheritance patterns (which is better)? What are the best practices for professional applications? How do we know what sloppy code looks like, and how do we avoid creating sloppy code? Are there any best practices regarding the design of Winforms applications?

    Read the article

  • What is a useful pattern to maintaining an object state in a one to many relationship?

    - by ahenderson
    I am looking for a design for my application, here are the players(classes) involved. struct Transform { // Uses a matrix to transform the position. // Also acts acts as the state of a Dialog. Position transform(Position p); //other methods. }; struct Dialog { // There are multiple dialog for the user to transform the output. Transform& t; void ChangeTranformation(){t.rotate(360);} } struct Algorithm { //gives us a position based on an implementation. For example this can return points on a circle or line. Transform& t; Position m_p; Dialog& d; Position GetCurrentPosition(){ return t.transform(m_p);} //other methods. } Properties I need: Each algorithms has one dialog and each dialog can have many algorithms associated with it. When the user selects an algorithm a dialog associated with that algorithm is displayed. If the user selects a different algorithm then re-selects back the state is restored in the dialog. Basically I want a good design pattern to maintain the state of the dialog given that many algorithms use it and they can be switched back and forth. Does anyone have any suggestions? Here is a use case: Dialog1 has a single edit box to control the radius. Algorithm1 generates points on a unit circle. Algorithm2 is the same as Algorithm1. The user has selected Algorithm1 and entered 2 into the edit box. This will generate points on a circle of radius 2. The user then selects Algorithm2 and enters 10 into the edit box of Dialog1. This will generate points on a circle of radius 10. Finally Algorithm1 is selected again. The edit box of Dialog1 should show 2 and points on a circle of radius 2 should be generated.

    Read the article

  • How can you tell whether to use Composite Pattern or a Tree Structure, or a third implementation?

    - by Aske B.
    I have two client types, an "Observer"-type and a "Subject"-type. They're both associated with a hierarchy of groups. The Observer will receive (calendar) data from the groups it is associated with throughout the different hierarchies. This data is calculated by combining data from 'parent' groups of the group trying to collect data (each group can have only one parent). The Subject will be able to create the data (that the Observers will receive) in the groups they're associated with. When data is created in a group, all 'children' of the group will have the data as well, and they will be able to make their own version of a specific area of the data, but still linked to the original data created (in my specific implementation, the original data will contain time-period(s) and headline, while the subgroups specify the rest of the data for the receivers directly linked to their respective groups). However, when the Subject creates data, it has to check if all affected Observers have any data that conflicts with this, which means a huge recursive function, as far as I can understand. So I think this can be summed up to the fact that I need to be able to have a hierarchy that you can go up and down in, and some places be able to treat them as a whole (recursion, basically). Also, I'm not just aiming at a solution that works. I'm hoping to find a solution that is relatively easy to understand (architecture-wise at least) and also flexible enough to be able to easily receive additional functionality in the future. Is there a design pattern, or a good practice to go by, to solve this problem or similar hierarchy problems? EDIT: Here's the design I have: The "Phoenix"-class is named that way because I didn't think of an appropriate name yet. But besides this I need to be able to hide specific activities for specific observers, even though they are attached to them through the groups. A little Off-topic: Personally, I feel that I should be able to chop this problem down to smaller problems, but it escapes me how. I think it's because it involves multiple recursive functionalities that aren't associated with each other and different client types that needs to get information in different ways. I can't really wrap my head around it. If anyone can guide me in a direction of how to become better at encapsulating hierarchy problems, I'd be very glad to receive that as well.

    Read the article

  • Flags with deferred use

    - by Trenton Maki
    Let's say I have a system. In this system I have a number of operations I can do but all of these operations have to happen as a batch at a certain time, while calls to activate and deactivate these operations can come in at any time. To implement this, I could use flags like doOperation1 and doOperation2 but this seems like it would become difficult to maintain. Is there a design pattern, or something similar, that addresses this situation?

    Read the article

  • Associating an Object with other Objects and Properties of those Objects

    - by alzoid
    I am looking for some help with designing some functionality in my application. I already have something similar designed but this problem is a little different. Background: In my application we have different Modules. Data in each module can be associated to other modules. Each Module is represented by an Object in our application. Module 1 can be associated with Module 2 and Module 3. Currently I use a factory to provide the proper DAO for getting and saving this data. It looks something like this: class Module1Factory { public static Module1BridgeDAO createModule1BridgeDAO(int moduleid) { switch (moduleId) { case Module.Module2Id: return new Module1_Module2DAO(); case Module.Module3Id: return new Module1_Module3DAO(); default: return null; } } } Module1_Module2 and Module1_Module3 implement the same BridgeModule interface. In the database I have a Table for every module (Module1, Module2, Module3). I also have a bridge table for each module (they are many to many) Module1_Module2, Module1_Module3 etc. The DAO basically handles all code needed to manage the association and retrieve its own instance data for the calling module. Now when we add new modules that associate with Module1 we simply implement the ModuleBridge interface and provide the common functionality. New Development We are adding a new module that will have the ability to be associated with other Modules as well as specific properties of that module. The module is basically providing the user the ability to add their custom forms to our other modules. That way they can collect additional information along with what we provide. I want to start associating my Form module with other modules and their properties. Ie if Module1 has a property Category, I want to associate an instance From data with that property. There are many Forms. If a users creates an instance of Module2, they may always want to also have certain form(s) attached to that Module2 instance. If they create an instance of Module2 and select Category 1, then I may want additional Form(s) created. I prototyped something like this: Form FormLayout (contains the labels and gui controls) FormModule (associates a form with all instances of a module) Form Instance (create an instance of a form to be filled out) As I thought about it I was thinking about making a new FormModule table/class/dao for each Module and Property that I add. So I might have: FormModule1 FormModule1Property1 FormModule1Property2 FormModule1Property3 FormModule1Property4 FormModule2 FormModule3 FormModule3Property1 Then as I did previously, I would use a factory to get the proper DAO for dealing with all of these. I would hand it an array of ids representing different modules and properties and it would return all of the DAOs that I need to call getForms(). Which in turn would return all of the forms for that particular bridge. Some points This will be for a new module so I dont need to expand on the factory code I provided. I just wanted to show an example of what I have done in the past. The new module can be associated with: Other Modules (ie globally for any instance of that module data), Other module properties (ie only if the Module instance has a certian value in one of its properties) I want to make it easy for developers to add associations with other modules and properties easily Can any one suggest any design patterns or strategy's for achieving this? If anything is unclear please let me know. Thank you, Al

    Read the article

  • Design Question - how do you break the dependency between classes using an interface?

    - by Seth Spearman
    Hello, I apologize in advance but this will be a long question. I'm stuck. I am trying to learn unit testing, C#, and design patterns - all at once. (Maybe that's my problem.) As such I am reading the Art of Unit Testing (Osherove), and Clean Code (Martin), and Head First Design Patterns (O'Reilly). I am just now beginning to understand delegates and events (which you would see if you were to troll my SO questions of recent). I still don't quite get lambdas. To contextualize all of this I have given myself a learning project I am calling goAlarms. I have an Alarm class with members you'd expect (NextAlarmTime, Name, AlarmGroup, Event Trigger etc.) I wanted the "Timer" of the alarm to be extensible so I created an IAlarmScheduler interface as follows... public interface AlarmScheduler { Dictionary<string,Alarm> AlarmList { get; } void Startup(); void Shutdown(); void AddTrigger(string triggerName, string groupName, Alarm alarm); void RemoveTrigger(string triggerName); void PauseTrigger(string triggerName); void ResumeTrigger(string triggerName); void PauseTriggerGroup(string groupName); void ResumeTriggerGroup(string groupName); void SetSnoozeTrigger(string triggerName, int duration); void SetNextOccurrence (string triggerName, DateTime nextOccurrence); } This IAlarmScheduler interface define a component that will RAISE an alarm (Trigger) which will bubble up to my Alarm class and raise the Trigger Event of the alarm itself. It is essentially the "Timer" component. I have found that the Quartz.net component is perfectly suited for this so I have created a QuartzAlarmScheduler class which implements IAlarmScheduler. All that is fine. My problem is that the Alarm class is abstract and I want to create a lot of different KINDS of alarm. For example, I already have a Heartbeat alarm (triggered every (int) interval of minutes), AppointmentAlarm (triggered on set date and time), Daily Alarm (triggered every day at X) and perhaps others. And Quartz.NET is perfectly suited to handle this. My problem is a design problem. I want to be able to instantiate an alarm of any kind without my Alarm class (or any derived classes) knowing anything about Quartz. The problem is that Quartz has awesome factories that return just the right setup for the Triggers that will be needed by my Alarm classes. So, for example, I can get a Quartz trigger by using TriggerUtils.MakeMinutelyTrigger to create a trigger for the heartbeat alarm described above. Or TriggerUtils.MakeDailyTrigger for the daily alarm. I guess I could sum it up this way. Indirectly or directly I want my alarm classes to be able to consume the TriggerUtils.Make* classes without knowing anything about them. I know that is a contradiction, but that is why I am asking the question. I thought about putting a delegate field into the alarm which would be assigned one of these Make method but by doing that I am creating a hard dependency between alarm and Quartz which I want to avoid for both unit testing purposes and design purposes. I thought of using a switch for the type in QuartzAlarmScheduler per here but I know it is bad design and I am trying to learn good design. If I may editorialize a bit. I've decided that coding (predefined) classes is easy. Design is HARD...in fact, really hard and I am really fighting feeling stupid right now. I guess I want to know if you really smart people took a while to really understand and master this stuff or should I feel stupid (as I do) because I haven't grasped it better in the couple of weeks/months I have been studying. You guys are awesome and thanks in advance for your answers. Seth

    Read the article

  • DB Design Pattern - Many to many classification / categorised tagging.

    - by Robin Day
    I have an existing database design that stores Job Vacancies. The "Vacancy" table has a number of fixed fields across all clients, such as "Title", "Description", "Salary range". There is an EAV design for "Custom" fields that the Clients can setup themselves, such as, "Manager Name", "Working Hours". The field names are stored in a "ClientText" table and the data stored in a "VacancyClientText" table with VacancyId, ClientTextId and Value. Lastly there is a many to many EAV design for custom tagging / categorising the vacancies with things such as Locations/Offices the vacancy is in, a list of skills required. This is stored as a "ClientCategory" table listing the types of tag, "Locations, Skills", a "ClientCategoryItem" table listing the valid values for each Category, e.g., "London,Paris,New York,Rome", "C#,VB,PHP,Python". Finally there is a "VacancyClientCategoryItem" table with VacancyId and ClientCategoryItemId for each of the selected items for the vacancy. There are no limits to the number of custom fields or custom categories that the client can add. I am now designing a new system that is very similar to the existing system, however, I have the ability to restrict the number of custom fields a Client can have and it's being built from scratch so I have no legacy issues to deal with. For the Custom Fields my solution is simple, I have 5 additional columns on the Vacancy Table called CustomField1-5. This removes one of the EAV designs. It is with the tagging / categorising design that I am struggling. If I limit a client to having 5 categories / types of tag. Should I create 5 tables listing the possible values "CustomCategoryItems1-5" and then an additional 5 many to many tables "VacancyCustomCategoryItem1-5" This would result in 10 tables performing the same storage as the three tables in the existing system. Also, should (heaven forbid) the requirements change in that I need 6 custom categories rather than 5 then this will result in a lot of code change. Therefore, can anyone suggest any DB Design Patterns that would be more suitable to storing such data. I'm happy to stick with the EAV approach, however, the existing system has come across all the usual performance issues and complex queries associated with such a design. Any advice / suggestions are much appreciated. The DBMS system used is SQL Server 2005, however, 2008 is an option if required for any particular pattern.

    Read the article

  • Why is good UI design so hard for some Developers?

    - by Chris Ballance
    Some of us just have a hard time with the softer aspects of UI design (myself especially). Are "back-end coders" doomed to only design business logic and data layers? Is there something we can do to retrain our brain to be more effective at designing pleasing and useful presentation layers? Colleagues have recommended a few books me including The Design of Sites, Don't make me think and Why Software sucks , but I am wondering what others have done to remove their deficiencies in this area?

    Read the article

  • how good should a developer be in design and animation?

    - by scatman
    how good should a developer (especially web developer) be in design and animation? should he know how to create flash animations? how to use image processing programs like photoshop.... i am asking this question because i am a computer science student, and all my courses are programming related (no courses about design). when i develop a web application i usually use "wizards" for animation coz i suck at design...

    Read the article

  • What design patters are the worst or most narrowly defined?

    - by Akku
    For every programming project, Managers with past programming experience try to shine when they recommend some design patterns for your project. I like design patterns when they make sense or if you need a scalbale solution. I've used Proxies, Observers and Command patterns in a positive way for example, and do so every day. But I'm really hesitant to use say a Factory pattern if there's only one way to create an object, as a factory might make it all easier in the future, but complicates the code and is pure overhead. So, my question is in respect to my future career and my answer to manager types throwing random pattern-names around: Which design patterns did you use, that threw you back overall? Which are the worst design patterns, that you shouldn't have a look at if it's not that only single situation where it makes sense (read: which design patterns are very narrowly defined)? (It's like I was looking for the negative reviews of an overall good product of amazon to see what bugged people most in using design patterns). And I'm not talking about Anti-Patterns here, but about Patterns that are usually thought of as "good" patterns.

    Read the article

  • What design patterns are the worst or most narrowly defined?

    - by Akku
    For every programming project, Managers with past programming experience try to shine when they recommend some design patterns for your project. I like design patterns when they make sense or if you need a scalbale solution. I've used Proxies, Observers and Command patterns in a positive way for example, and do so every day. But I'm really hesitant to use say a Factory pattern if there's only one way to create an object, as a factory might make it all easier in the future, but complicates the code and is pure overhead. So, my question is in respect to my future career and my answer to manager types throwing random pattern-names around: Which design patterns did you use, that threw you back overall? Which are the worst design patterns, that you shouldn't have a look at if it's not that only single situation where it makes sense (read: which design patterns are very narrowly defined)? (It's like I was looking for the negative reviews of an overall good product of amazon to see what bugged people most in using design patterns). And I'm not talking about Anti-Patterns here, but about Patterns that are usually thought of as "good" patterns. Edit: As some answered, the problem is most often that patterns are not "bad" but "used wrong". If you know patterns, that are often misused or even difficult to use, they would also fit as an answer.

    Read the article

  • Has the emerging generation of programmers got the wrong idea about design patterns? [closed]

    - by MattDavey
    Over the years I've noticed a shift in attitude towards design patterns, particularly amongst the emerging generation of developers. There seems to be a notion these days that design patterns are silver bullets that instantly cure any problem, a proliferating idea that advancing as a software engineer simply means learning and applying more and more patterns. When confronted with a problem, developers no longer strive to truly understand the issue and design a solution - instead they simply pick a design pattern which seems to be a close fit, and try to brute-force it. You can see evidence of this by the many, many questions on Stack Overflow that begin with the phrase "what pattern should I use to...". I fall into a slightly more mature category of developers (5-10 years experience) and I have a very different viewpoint on patterns - simply as a communication tool to enhance clarity. I find this perspective of design patterns being lego bricks (collected like pokemon cards) a little disconcerting. Will developers lose this attitude as they gain more experience in software engineering? Or could these notions perhaps steer the direction of our craft in years to come? Did the older generation of developers have any similar concerns about us? (perhaps about OO design or similar...). if so, how did we turn out?

    Read the article

  • Download all the links from a website at once [closed]

    - by user216112
    Possible Duplicate: How can I download an entire website Is there any software that allows you to download all the links of a website at once? E.g.: I'm using the w3school.com site and want to download all the PHP tutorials at once. Someone told me "tglepote".bt I have no idea what it is and Google returns me with nothing.

    Read the article

  • How to register rss for a website?

    - by domainking
    I am not sure if I ask this question in the right place, because I am new to it. What I want to ask is, do I need to register/create RSS for my website? I have a website, lets say: [http://blog.domain.com] = its a 2.9.2 wordpress blog So, if I want to display the latest content in another subdomain, for example: [news.domain.com], how do I do that? I know a little bit of php and mysql.

    Read the article

  • Should pathfinder in A* hold closedSet and openedSet or each object should hold its sets?

    - by Patryk
    I am about to implement A* pathfinding algorithm and I wonder how should I implement this - from the point of view of architecture. I have the pathfinder as a class - I think I will instantiate only one object of this class (or maybe make it a Singleton - this is not so important). The hardest part for me is whether the closedSet and openedSet should be attached to objects that can find the path for them or should be stored in pathfinder class ? I am opened to any hints and critique whatsoever. What is the best practice considering pathfinding in terms of design ?

    Read the article

  • When should we use weak entities when modelling a database?

    - by Songo
    This is basically a question about what are weak entities? When should we use them? How should they be modeled? What is the main difference between normal entities and weak entities? Does weak entities correspond to value objects when doing Domain Driven Design? To help keep the question on topic here is an example taken from Wikipedia that people can use to answer these question: In this example OrderItem was modeled as a weak entity, but I can't understand why it can't be modeled as a normal entity. Another question is what if I want to track the order history (i.e. the changes in it status) would that be a normal or weak entity?

    Read the article

  • What is a best practice tier structure of a Java EE 6/7 application?

    - by James Drinkard
    I was attempting to find a best practice for modeling the tiers in a Java EE application yesterday and couldn't come up with anything current. In the past, say java 1.4, it was four tiers: Presentation Tier Web Tier Business Logic Tier DAL (Data Access Layer ) which I always considered a tier and not a layer. After working with Web Services and SOA I thought to add in a services tier, but that may fall under 3. the business logic tier. I did searches for quite a while and reading articles. It seems like Domain Driven Design is becoming more popular, but I couldn't find a diagram on it's tier structure. Anyone have ideas or diagrams on what the proper tier structure is for newer Java EE applications or is it really the same, but more items are ranked under the four I've mentioned?

    Read the article

  • Customizing configuration with Dependency Injection

    - by mathieu
    I'm designing a small application infrastructure library, aiming to simplify development of ASP.NET MVC based applications. Main goal is to enforce convention over configuration. Hovewer, I still want to make some parts "configurable" by developpers. I'm leaning towards the following design: public interface IConfiguration { SomeType SomeValue; } // this one won't get registered in container protected class DefaultConfiguration : IConfiguration { public SomeType SomeValue { get { return SomeType.Default; } } } // declared inside 3rd party library, will get registered in container protected class CustomConfiguration : IConfiguration { public SomeType SomeValue { get { return SomeType.Custom; } } } And the "service" class : public class Service { private IConfiguration conf = new DefaultConfiguration(); // optional dependency, if found, will be set to CustomConfiguration by DI container public IConfiguration Conf { get { return conf; } set { conf = value; } } public void Configure() { DoSomethingWith( Conf ); } } There, the "configuration" part is clearly a dependency of the service class, but it this an "overuse" of DI ?

    Read the article

  • How does a search functionality fit in DDD with CQRS?

    - by Songo
    In Vaughn Vernon's book Implementing domain driven design and the accompanying sample application I found that he implemented a CQRS approach to the iddd_collaboration bounded context. He presents the following classes in the application service layer: CalendarApplicationService.java CalendarEntryApplicationService.java CalendarEntryQueryService.java CalendarQueryService.java I'm interested to know if an application will have a search page that feature numerous drop downs and check boxes with a smart text box to match different search patterns; How will you structure all that search logic? In a command service or a query service? Taking a look at the CalendarQueryService.java I can see that it has 2 methods for a huge query, but no logic at all to mix and match any search filters for example. I've heard that the application layer shouldn't have any business logic, so where will I construct my dynamic query? or maybe just clutter everything in the Query service?

    Read the article

< Previous Page | 18 19 20 21 22 23 24 25 26 27 28 29  | Next Page >