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  • Is ASP.NET MVC is really MVC? Or how to separate model from controller?

    - by Andrey
    Hi all, This question is a bit rhetorical. At some point i got a feeling that ASP.NET MVC is not that authentic implementation of MVC pattern. Or i didn't understood it. Consider following domain: electric bulb, switch and motion detector. They are connected together and when you enter the room motion detector switches on the bulb. If i want to represent them as MVC: switch is model, because it holds the state and contains logic bulb is view, because it presents the state of model to human motion detector is controller, because it converts user actions to generic model commands Switch has one private field (On/Off) as a State and two methods (PressOn, PressOff). If you call PressOn when it is Off it goes to On, if you call it again state doesn't change. Bulb can be replaced with buzzer, motion detector with timer or button, but the model still represent the same logic. Eventually system will have same behavior. This is how i understand classical MVC decomposition, please correct me if i am wrong. Now let's decompose it in ASP.Net MVC way. Bulb is still a view Controller will be switch + motion detector Model is some object that will just pass state to bulb. So the logic that defines behavior moves to controller. Question 1: Is my understanding of MVC and ASP.NET MVC correct? Question 2: If yes, do you agree that ASP.NET MVC is not 100% accurate implementation? And back to life. The final question is how to separate model from controller in case of ASP.NET MVC. There can be two extremes. Controller does basic stuff and call model to do all the logic. Another is controller does all the logic and model is just something like class with properties that is mapped to DB. Question 3: Where should i draw the line between this extremes? How to balance? Thanks, Andrey

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  • Interface Design Problem: Storing Result of Transactions

    - by jboyd
    Requirements: multiple sources of input (social media content) into a system multiple destinations of output (social media api's) sources and destinations WILL be added some pseudo: IContentProvider contentProvider = context.getBean("contentProvider"); List<Content> toPost = contentProvider.getContent(); for (Content c : toPost) { SocialMediaPresence smPresence = socialMediaService.getSMPresenceBySomeId(c.getDestId()); smPresence.hasTwitter(); smPresence.hasFacebook(); //just to show what this is smPresence.postContent(c); //post content could fail for some SM platforms, but shoulnd't be lost forever } So now I run out of steam, I need to know what content has been successfully posted, and if it hasn't gone too all platforms, or if another platform were added in the future that content needs to go out for it as well (therefore my content provider will need to not only know if content has gone out, but for what platforms). I'm not looking for code, although sample/pseudo is fine... I'm looking for an approach to this problem that I can implement

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  • How to change easily between ajax-based website and basic HTML website?

    - by A.S al-shammari
    Hi, I have a website ( based on JSP/Servlets ,using MVC pattern), and I want to support AJAX-based website and basic HTML-based website. website visitors should be able to change the surfing mode from Ajax to basic HTML and vise versa, - as it applies in Google-mail. The Questions : What is the best way to achieve this goal easily? Should I design two views for each page? I use JQuery and JSON as the result of this answer.

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  • How to avoid using this in a constructor

    - by Paralife
    I have this situation: interface MessageListener { void onMessageReceipt(Message message); } class MessageReceiver { MessageListener listener; public MessageReceiver(MessageListener listener, other arguments...) { this.listener = listener; } loop() { Message message = nextMessage(); listener.onMessageReceipt(message); } } and I want to avoid the following pattern: (Using the this in the Client constructor) class Client implements MessageListener { MessageReceiver receiver; MessageSender sender; public Client(...) { receiver = new MessageReceiver(this, other arguments...); sender = new Sender(...); } . . . @Override public void onMessageReceipt(Message message) { if(Message.isGood()) sender.send("Congrtulations"); else sender.send("Boooooooo"); } } The reason why i need the above functionality is because i want to call the sender inside the onMessageReceipt() function, for example to send a reply. But I dont want to pass the sender into a listener, so the only way I can think of is containing the sender in a class that implements the listener, hence the above resulting Client implementation. Is there a way to achive this without the use of 'this' in the constructor? It feels bizare and i dont like it, since i am passing myself to an object(MessageReceiver) before I am fully constructed. On the other hand, the MessageReceiver is not passed from outside, it is constructed inside, but does this 'purifies' the bizarre pattern? I am seeking for an alternative or an assurance of some kind that this is safe, or situations on which it might backfire on me.

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  • Can you find a pattern to sync files knowing only dates and filenames?

    - by Robert MacLean
    Imagine if you will a operating system that had the following methods for files Create File: Creates (writes) a new file to disk. Calling this if a file exists causes a fault. Update File: Updates an existing file. Call this if a file doesn't exist causes a fault. Read File: Reads data from a file. Enumerate files: Gets all files in a folder. Files themselves in this operating system only have the following meta data: Created Time: The original date and time the file was created, by the Create File method. Modified Time: The date and time the file was last modified by the Update File method. If the file has never been modified, this will equal the Create Time. You have been given the task of writing an application which will sync the files between two directories (lets call them bill and ted) on a machine. However it is not that simple, the client has required that The application never faults (see methods above). That while the application is running the users can add and update files and those will be sync'd next time the application runs. Files can be added to either the ted or bill directories. File names cannot be altered. The application will perform one sync per time it is run. The application must be almost entirely in memory, in other words you cannot create a log of filenames and write that to disk and then check that the next time. The exception to point 6 is that you can store date and times between runs. Each date/time is associated with a key labeled A through J (so you have 10 to use) so you can compare keys between runs. There is no way to catch exceptions in the application. Answer will be accepted based on the following conditions: First answer to meet all requirements will be accepted. If there is no way to meet all requirements, the answer which ensures the smallest amount of missed changes per sync will be accepted. A bounty will be created (100 points) as soon as possible for the prize. The winner will be selected one day before the bounty ends. Please ask questions in the comments and I will gladly update and refine the question on those.

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  • Which Code Should Go Where in MVC Structure

    - by Oguz
    My problem is in somewhere between model and controller.Everything works perfect for me when I use MVC just for crud (create, read, update, delete).I have separate models for each database table .I access these models from controller , to crud them . For example , in contacts application,I have actions (create, read, update, delete) in controller(contact) to use model's (contact) methods (create, read, update, delete). The problem starts when I try to do something more complicated. There are some complex processes which I do not know where should I put them. For example , in registering user process. I can not just finish this process in user model because , I have to use other models too (sending mails , creating other records for user via other models) and do lots of complex validations via other models. For example , in some complex searching processes , I have to access lots of models (articles, videos, images etc.) Or, sometimes , I have to use apis to decide what I will do next or which database model I will use to record data So where is the place to do this complicated processes. I do not want to do them in controllers , Because sometimes I should use these processes in other controllers too. And I do not want to put these process in models because , I use models as database access layers .May be I am wrong,I want to know . Thank you for your answer .

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  • Observer pattern and violation of Single Principality Rule

    - by Devil Jin
    I have an applet which repaints itself once the text has changed Design 1: //MyApplet.java public class MyApplet extends Applet implements Listener{ private DynamicText text = null; public void init(){ text = new DynamicText("Welcome"); } public void paint(Graphics g){ g.drawString(text.getText(), 50, 30); } //implement Listener update() method public void update(){ repaint(); } } //DynamicText.java public class DynamicText implements Publisher{ // implements Publisher interface methods //notify listeners whenever text changes } Isn't this a violation of Single Responsibility Principle where my Applet not only acts as Applet but also has to do Listener job. Same way DynamicText class not only generates the dynamic text but updates the registered listeners. Design 2: //MyApplet.java public class MyApplet extends Applet{ private AppletListener appLstnr = null; public void init(){ appLstnr = new AppletListener(this); // applet stuff } } // AppletListener.java public class AppletListener implements Listener{ private Applet applet = null; public AppletListener(Applet applet){ this.applet = applet; } public void update(){ this.applet.repaint(); } } // DynamicText public class DynamicText{ private TextPublisher textPblshr = null; public DynamicText(TextPublisher txtPblshr){ this.textPblshr = txtPblshr; } // call textPblshr.notifyListeners whenever text changes } public class TextPublisher implments Publisher{ // implements publisher interface methods } Q1. Is design 1 a SPR violation? Q2. Is composition a better choice here to remove SPR violation as in design 2.

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  • Singleton class design in C#, are these two classes equivalent?

    - by Oskar
    I was reading up on singleton class design in C# on this great resource and decided to go with alternative 4: public sealed class Singleton1 { static readonly Singleton1 _instance = new Singleton1(); static Singleton1() { } Singleton1() { } public static Singleton1 Instance { get { return _instance; } } } Now I wonder if this can be rewritten using auto properties like this? public sealed class Singleton2 { static Singleton2() { Instance = new Singleton2(); } Singleton2() { } public static Singleton2 Instance { get; private set; } } If its only a matter of readability I definitely prefer the second version, but I want to get it right.

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  • Tracking the user function that threw the exception

    - by makerofthings7
    I've been given a large application with only one try..catch at the outer most level. This application also throws exceptions all the time, and is poorly documented. Is there any pattern I can implement that will tell me what user method is being called, the exception being thrown, and also the count of exceptions? I'm thinking of using a dictionary with reflection to get the needed information, but I'm not sure if this will work. What do you think?

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  • How to perform a literal match with regex using wildcard

    - by kashif4u
    I am trying to perform literal match with regular expression using wildcard. string utterance = "Show me customer id 19"; string pattern 1 = "*tom*"; string patter 2 = "*customer id [0-9]*"; Desired results: if (Regex.IsMatch(utterance, pattern 1 )) { MATCH NOT FOUND } if (Regex.IsMatch(utterance, pattern 2 )) { MATCH FOUND } I have tried looking for literal match solution/syntax in wildcard but having difficulty. Could you also enlighten me with with an example on possible Pattern Matching Strength algorithm i.e. if code match 90 select? Note: I have table with 100000 records to perform literal matches from user utterances. Thanks in advance.

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  • Refactoring a C# derived class with method dependancies

    - by drelihan
    Hi Folks, I want to get your opinion on this. I have a class which is derived from a base class. I don't have control over the code in the base class and it is critical to the system that I derive from it. In my class I inherite two methods that are critical to the system and are used in pretty much every function, many times. I intend to refactor this derived class and extract some classes from it - this won't be a problem. What I'm not sure about is, is it worth extracting class if I have to constantly make call backs to my main class to access the two methods (or public wrappers to the methods)??? Thanks

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  • What software design pattern is best for the following scenario (C#)

    - by askjdh
    I have a gps device that records data e.g. datetime, latitude, longitude I have an sdk that reads the data from the device. The way the data is read: A command packet (basically a combination of int values in a struct) is sent to the device. The device responds with the data in fixed size chunks e.g. 64bytes Depending on the command issued I will get back differect data structs e.g. sending command 1 to the device returns a struct like struct x { id int, name char[20] } command 2 returns a collection of the following structs (basically it boils down to an array of the structs - y[12]) struct y { date datetime, lat decimal, lon decimal } I would then want to convert the struct to a class and save the data to a database. What would be the best way to encapsulate the entire process, preferably using some established design pattern? Many thanks M

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  • Factory Method Implementation

    - by cedar715
    I was going through the 'Factory method' pages in SO and had come across this link. And this comment. The example looked as a variant and thought to implement in its original way: to defer instantiation to subclasses... Here is my attempt. Does the following code implements the Factory pattern of the example specified in the link? Please validate and suggest if this has to undergo any re-factoring. public class ScheduleTypeFactoryImpl implements ScheduleTypeFactory { @Override public IScheduleItem createLinearScheduleItem() { return new LinearScheduleItem(); } @Override public IScheduleItem createVODScheduleItem() { return new VODScheduleItem(); } } public class UseScheduleTypeFactory { public enum ScheduleTypeEnum { CableOnDemandScheduleTypeID, BroadbandScheduleTypeID, LinearCableScheduleTypeID, MobileLinearScheduleTypeID } public static IScheduleItem getScheduleItem(ScheduleTypeEnum scheduleType) { IScheduleItem scheduleItem = null; ScheduleTypeFactory scheduleTypeFactory = new ScheduleTypeFactoryImpl(); switch (scheduleType) { case CableOnDemandScheduleTypeID: scheduleItem = scheduleTypeFactory.createVODScheduleItem(); break; case BroadbandScheduleTypeID: scheduleItem = scheduleTypeFactory.createVODScheduleItem(); break; case LinearCableScheduleTypeID: scheduleItem = scheduleTypeFactory.createLinearScheduleItem(); break; case MobileLinearScheduleTypeID: scheduleItem = scheduleTypeFactory.createLinearScheduleItem(); break; default: break; } return scheduleItem; } }

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  • Best Design pattern for social media file transfer

    - by Onema
    Our system would like our clients to link their accounts with different social media sites like youtube, vimeo, facebook, myspace and so on. One of the benefits we would like to give to the user is to transfer, update and delete files they have uploaded to our sites and transfer them to the social media sites mentioned above. this files could be videos, images or audio. We started thinking about using a strategy pattern, as all of these sites share a common process ( authentication, connection, use the API to transfer/edit/delete the file ), but we soon realized that it may not work as me may want to use some of the extended functionality that is specific to each service (eg: associate a youtube video with a channel, or upload images to a specific album on facebook, and much, much more...) My question is, what would be the best Structural Design Patter to use for this scenario?

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  • How to avoid injecting dependencies into an object so that it can pass them on?

    - by Pheter
    I am interested in applying dependency injection to my current project, which makes use of the MVC pattern. My controllers will call the models and therefore will need to inject the dependencies into the models. To do this, the controller must have the dependencies (such as a database object) in the first place. The controller doesn't need to make use of some of these dependencies (such as the database object), so I feel that it shouldn't be given this dependency. However, it has to have these dependencies if it is to inject them into the model objects. How can I avoid having dependencies injected into an object just so that it can pass them on? Doing so feels wrong and can result in many dependencies being injected into an object. Edit: I am using PHP.

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  • Gmail-like labelling system

    - by Dimitris
    Hi I am looking into a number of ways to implement a labelling system similar to the one in Gmail. Basically I have a Resource at the lowest level and I would like to provide a number of organisational groupings for that resource in the form of labels. If anyone has implemented something like that I would like to hear your views. My idea is to have within the Resource instance a List<Label>. I need to have an efficient mechanism in order to do very fast searches based on the labels or based on the resources. Thanks Dimitris

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  • IoC, Containers, and NServiceBus confusion

    - by andy
    Hey guys, here's my setup Castle Windsor is my container NServiceBus is itself using it's own container internally, Spring by default I'm implementing the PubSub config. Ok, if I have my Bus.Publish happening within my IWantToRunAtStartup class, then everything is fine. As a test for example on Run() we can start a timer and it'll go into a Service style loop. However, what if I want to abstract NServiceBus from my app, and have my app go: new CustomPulisherClass().Notify(ISomeMessage msg); In this situation, how do I implement CustomPublisherClass. My confusion is coming from the fact that NServiceBus is already running as a Service, it's already been "Started". How to I get at the correct instance of the Bus object? cheers andy

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  • Validation with State Pattern for Multi-Page Forms in ASP.NET

    - by philrabin
    I'm trying to implement the state pattern for a multi-page registration form. The data on each page will be accumulated and stored in a session object. Should validation (including service layer calls to the DB) occur on the page level or inside each state class? In other words, should the concrete implementation of IState be concerned with the validation or should it be given a fully populated and valid object? See "EmptyFormState" class below: namespace Example { public class Registrar { private readonly IState formEmptyState; private readonly IState baseInformationComplete; public RegistrarSessionData RegistrarSessionData { get; set;} public Registrar() { RegistrarSessionData = new RegistrarSessionData(); formEmptyState = new EmptyFormState(this); baseInformationComplete = new BasicInfoCompleteState(this); State = formEmptyState; } public IState State { get; set; } public void SubmitData(RegistrarSessionData data) { State.SubmitData(data); } public void ProceedToNextStep() { State.ProceedToNextStep(); } } //actual data stored in the session //to be populated by page public class RegistrarSessionData { public string FirstName { get; set; } public string LastName { get; set; } //will include values of all 4 forms } //State Interface public interface IState { void SubmitData(RegistrarSessionData data); void ProceedToNextStep(); } //Concrete implementation of IState //Beginning state - no data public class EmptyFormState : IState { private readonly Registrar registrar; public EmptyFormState(Registrar registrar) { this.registrar = registrar; } public void SubmitData(RegistrarSessionData data) { //Should Validation occur here? //Should each state object contain a validation class? (IValidator ?) //Should this throw an exception? } public void ProceedToNextStep() { registrar.State = new BasicInfoCompleteState(registrar); } } //Next step, will have 4 in total public class BasicInfoCompleteState : IState { private readonly Registrar registrar; public BasicInfoCompleteState(Registrar registrar) { this.registrar = registrar; } public void SubmitData(RegistrarSessionData data) { //etc } public void ProceedToNextStep() { //etc } } }

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  • UML Class Relationships

    - by 01010011
    Hi, I would like to confirm whether I am on the right track when identifying common UML class relationships. For example, is the relationship between: 1 a stackoverflow member and his/her stackoverflow user account categorized as a composition relationship or an aggregation relationship? At first I thought it was an association because this member "has a" account. However on second thought, I am thinking its composition because each "part" (user account) belongs to only one whole (user) at a time, meaning for as long as I am logged into stackoverflow, I have to use this one and only account until I log off. If I log back onto stackoverflow with a different account then its composition again. Do you agree? 2 a database and a person's user account an aggregation relationship? I think so because 1 database (the whole) can store 0...* number of user accounts (the parts) but another database can store the same user accounts. Finally, can anyone recommend a website that specializes in designing code using UML? Thanks in advance

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  • How would you organize this Javascript?

    - by Anurag
    How do you usually organize complex web applications that are extremely rich on the client side. I have created a contrived example to indicate the kind of mess it's easy to get into if things are not managed well for big apps. Feel free to modify/extend this example as you wish - http://jsfiddle.net/NHyLC/1/ The example basically mirrors part of the comment posting on SO, and follows the following rules: Must have 15 characters minimum, after multiple spaces are trimmed out to one. If Add Comment is clicked, but the size is less than 15 after removing multiple spaces, then show a popup with the error. Indicate amount of characters remaining and summarize with color coding. Gray indicates a small comment, brown indicates a medium comment, orange a large comment, and red a comment overflow. One comment can only be submitted every 15 seconds. If comment is submitted too soon, show a popup with appropriate error message. A couple of issues I noticed with this example. This should ideally be a widget or some sort of packaged functionality. Things like a comment per 15 seconds, and minimum 15 character comment belong to some application wide policies rather than being embedded inside each widget. Too many hard-coded values. No code organization. Model, Views, Controllers are all bundled together. Not that MVC is the only approach for organizing rich client side web applications, but there is none in this example. How would you go about cleaning this up? Applying a little MVC/MVP along the way? Here's some of the relevant functions, but it will make more sense if you saw the entire code on jsfiddle: /** * Handle comment change. * Update character count. * Indicate progress */ function handleCommentUpdate(comment) { var status = $('.comment-status'); status.text(getStatusText(comment)); status.removeClass('mild spicy hot sizzling'); status.addClass(getStatusClass(comment)); } /** * Is the comment valid for submission */ function commentSubmittable(comment) { var notTooSoon = !isTooSoon(); var notEmpty = !isEmpty(comment); var hasEnoughCharacters = !isTooShort(comment); return notTooSoon && notEmpty && hasEnoughCharacters; } // submit comment $('.add-comment').click(function() { var comment = $('.comment-box').val(); // submit comment, fake ajax call if(commentSubmittable(comment)) { .. } // show a popup if comment is mostly spaces if(isTooShort(comment)) { if(comment.length < 15) { // blink status message } else { popup("Comment must be at least 15 characters in length."); } } // show a popup is comment submitted too soon else if(isTooSoon()) { popup("Only 1 comment allowed per 15 seconds."); } });

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  • What is the best software design to use in this scenario

    - by domdefelice
    I need to generate HTML snippets using jQuery. The creation of those snippets depends on some data. The data is stored server-side, in session (where PHP is used). At the moment I achieved this - retrieving the data from the server via AJAX in form of JSON - and building the snippets via specific javascript functions that read those data The problem is that the complexity of the data is getting bigger and hence the serialization into JSON is getting even more difficult since I can't do it automatically. I can't do it automatically because some information are sensible so I generate a "stripped" version to send to the client. I know it is difficult to understand without any code to read, but I am hoping this is a common scenario and would be glad for any tip, suggestion or even design-pattern you can give me. Should I store both a complete and a stripped data on the server and then use some library to automatically generate the JSON from the stripped data? But this also means I have to get the two data synchronized. Or maybe I could move the logic server-side, this way avoiding sending the data. But this means sending javascript code (since I rely on jQuery). Maybe not a good idea. Feel free to ask me more details if this is not clear. Thank you for any help

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  • Design pattern question: encapsulation or inheritance

    - by Matt
    Hey all, I have a question I have been toiling over for quite a while. I am building a templating engine with two main classes Template.php and Tag.php, with a bunch of extension classes like Img.php and String.php. The program works like this: A Template object creates a Tag objects. Each tag object determines which extension class (img, string, etc.) to implement. The point of the Tag class is to provide helper functions for each extension class such as wrap('div'), addClass('slideshow'), etc. Each Img or String class is used to render code specific to what is required, so $Img->render() would give something like <img src='blah.jpg' /> My Question is: Should I encapsulate all extension functionality within the Tag object like so: Tag.php function __construct($namespace, $args) { // Sort out namespace to determine which extension to call $this->extension = new $namespace($this); // Pass in Tag object so it can be used within extension return $this; // Tag object } function render() { return $this->extension->render(); } Img.php function __construct(Tag $T) { $args = $T->getArgs(); $T->addClass('img'); } function render() { return '<img src="blah.jpg" />'; } Usage: $T = new Tag("img", array(...); $T->render(); .... or should I create more of an inheritance structure because "Img is a Tag" Tag.php public static create($namespace, $args) { // Sort out namespace to determine which extension to call return new $namespace($args); } Img.php class Img extends Tag { function __construct($args) { // Determine namespace then call create tag $T = parent::__construct($namespace, $args); } function render() { return '<img src="blah.jpg" />'; } } Usage: $Img = Tag::create('img', array(...)); $Img->render(); One thing I do need is a common interface for creating custom tags, ie I can instantiate Img(...) then instantiate String(...), I do need to instantiate each extension using Tag. I know this is somewhat vague of a question, I'm hoping some of you have dealt with this in the past and can foresee certain issues with choosing each design pattern. If you have any other suggestions I would love to hear them. Thanks! Matt Mueller

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