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  • Record management system java web framework

    - by Kamil Tomšík
    We're currently reconsidering technologies and frameworks to get more agile with "simple" RMS CRUD-based projects. In short, short-living things like this Right now we have a custom extension on top of SmartGWT but after some time it has proven not to be flexible enough. I also personally dislike the java-js compilation process and the whole GWT codebase. Not only is the design ugly, it also makes certain low-level js things very complicated if not completely impossible. So what I'm looking for is: closest to web as possible, like JSF or possibly Tapestry, it is very important to be able get "low" and weave framework if necessary. Happens more often than we thought. datagrid capable - Ext.js & PrimeFaces looks pretty good, Vaadin does too. db-schema generators (optional, no matter in which way) If it were only on me, I'd probably stick to Ext.js + custom rest-based java solution, possibly generated from database schema (not sure about concrete tooling yet). I only have experience with vanilla Ext.js, vanilla GWT and JSF 2.0 / Seam, so it hard for me to judge or even propose other frameworks. What would be your proposition? What are the problems you've faced? What was your solution and how hard do you think it was to deal with them in "big picture"?

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  • Writing a new programming language - when and how to bootstrap datastructures?

    - by OnResolve
    I'm in the process of writing my own programming language which, thus far, has been going great in terms of what I set out to accomplish. However, now, I'd like to bootstrap some pre-existing data structures and/or objects. My problem is that I'm not really sure on how to begin. When the compiler begins do I splice in these add-ins so their part of the scope of the application? If I make these in some core library, my concern is how I distribute the library in addition to the compiler--or are they part of the compiler? I get that there are probably a number of plausible ways to approach this, but I'm having trouble with the setting my direction. If it helps, the language is on top of the .NET core (i.e it compiles to CLR code). Any help or suggestions are very much appreciated!

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  • How to design a scalable notification system?

    - by Trent
    I need to write a notification system manager. Here is my requirements: I need to be able to send a Notification on different platforms, which may be totally different (for exemple, I need to be able to send either an SMS or an E-mail). Sometimes the notification may be the same for all recipients for a given platform, but sometimes it may be a notification per recipients (or several) per platform. Each notification can contain platform specific payload (for exemple an MMS can contains a sound or an image). The system need to be scalable, I need to be able to send a very large amount of notification without crashing either the application or the server. It is a two step process, first a customer may type a message and choose a platform to send to, and the notification(s) should be created to be processed either real-time either later. Then the system needs to send the notification to the platform provider. For now, I end up with some though but I don't know how scalable it will be or if it is a good design. I've though of the following objects (in a pseudo language): a generic Notification object: class Notification { String $message; Payload $payload; Collection<Recipient> $recipients; } The problem with the following objects is what if I've 1.000.000 recipients ? Even if the Recipient object is very small, it'll take too much memory. I could also create one Notification per recipient, but some platform providers requires me to send it in batch, meaning I need to define one Notification with several Recipients. Each created notification could be stored in a persistent storage like a DB or Redis. Would it be a good it to aggregate this later to make sure it is scalable? On the second step, I need to process this notification. But how could I distinguish the notification to the right platform provider? Should I use an object like MMSNotification extending an abstract Notification? or something like Notification.setType('MMS')? To allow to process a lot of notification at the same time, I think a messaging queue system like RabbitMQ may be the right tool. Is it? It would allow me to queue a lot of notification and have several worker to pop notification and process them. But what if I need to batch the recipients as seen above? Then I imagine a NotificationProcessor object for which I could I add NotificationHandler each NotificationHandler would be in charge to connect the platform provider and perform notification. I can also use an EventManager to allow pluggable behavior. Any feedbacks or ideas? Thanks for giving your time. Note: I'm used to work in PHP and it is likely the language of my choice.

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  • Teaching myself, as a physicist, to become a better programmer

    - by user787267
    I've always liked physics, and I've always liked coding, so when I got the offer for a PhD position doing numerical physics (details are not relevant, it's mostly parallel programming for a cluster) at a university, it was a no-brainer for me. However, as most physicists, I'm self taught. I don't have broad background knowledge about how to code in an object oriented way, or the name of that specific algorithm that optimizes the search in some kD tree. Since all my work so far has been more concerned about the physics and the scientific results, I undoubtedly have some bad habits - more so because my coding is my own, and not really teamwork. I have mostly used C since it is very straightforward and "what you write is what you get" - no need for fancy abstractions. However, I have recently switched to C++ since I'd like to learn more about the power that comes with abstraction, and it's pretty C-like (syntax-wise at least). How do I teach myself to code in a good, abstract way like a graduate in computer science? I know my code is efficient, but I want it to be elegant as well, and readable. Keep in mind that I don't have time to read several 1000-page tomes about abstract programming. I need to spend time on actual, physics related research (my supervisor would laugh at me if he knew I spent time thinking about how to program elegantly). How do I assess if my work is also good from a programmer's perspective?

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  • Catering for client's web-hosting needs, minus the headaches ?

    - by julien
    I'll be trying to sell my Ruby on Rails development skills to small local businesses. It seems I'd be shooting myself in the foot if I couldn't manage to put their apps into production, in fact catering for this would be a selling point. However, I do not want to bill every client monthly for the cost of their hosting, they would have to be the contract holders with the hosting service, and I'd only consult if they needed technical help when scaling. I've looked on one hand at cloud platforms, like engine yard, which seem like they would be too costly for the smaller clients, and on the other hand at vps providers which seem they would not be client friendly enough. Has anyone faced the same issue and come up with a decent solution ?

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  • Is commented out code really always bad?

    - by nikie
    Practically every text on code quality I've read agrees that commented out code is a bad thing. The usual example is that someone changed a line of code and left the old line there as a comment, apparently to confuse people who read the code later on. Of course, that's a bad thing. But I often find myself leaving commented out code in another situation: I write a computational-geometry or image processing algorithm. To understand this kind of code, and to find potential bugs in it, it's often very helpful to display intermediate results (e.g. draw a set of points to the screen or save a bitmap file). Looking at these values in the debugger usually means looking at a wall of numbers (coordinates, raw pixel values). Not very helpful. Writing a debugger visualizer every time would be overkill. I don't want to leave the visualization code in the final product (it hurts performance, and usually just confuses the end user), but I don't want to loose it, either. In C++, I can use #ifdef to conditionally compile that code, but I don't see much differnce between this: /* // Debug Visualization: draw set of found interest points for (int i=0; i<count; i++) DrawBox(pts[i].X, pts[i].Y, 5,5); */ and this: #ifdef DEBUG_VISUALIZATION_DRAW_INTEREST_POINTS for (int i=0; i<count; i++) DrawBox(pts[i].X, pts[i].Y, 5,5); #endif So, most of the time, I just leave the visualization code commented out, with a comment saying what is being visualized. When I read the code a year later, I'm usually happy I can just uncomment the visualization code and literally "see what's going on". Should I feel bad about that? Why? Is there a superior solution? Update: S. Lott asks in a comment Are you somehow "over-generalizing" all commented code to include debugging as well as senseless, obsolete code? Why are you making that overly-generalized conclusion? I recently read Robert Glass' "Clean Code", which says: Few practices are as odious as commenting-out code. Don't do this!. I've looked at the paragraph in the book again (p. 68), there's no qualification, no distinction made between different reasons for commenting out code. So I wondered if this rule is over-generalizing (or if I misunderstood the book) or if what I do is bad practice, for some reason I didn't know.

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  • Why are exceptions considered better than explicit error testing?

    - by Richard Keller
    I often come across heated blog posts where the author uses the argument of "exceptions vs explicit error checking" to advocate their preferred language over some other language. The general consensus seems to be that languages which make use of exceptions are inherently better / cleaner than languages which rely heavily on error checking through explicit function calls. Is the use of exceptions considered better programming practice than explicit error checking, and if so, why?

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  • Is there a procedural graphical programming environment?

    - by Marc
    I am searching for a graphical programming environment for procedural programming in which you can integrate some or all of the common sources of calculation procedures, such as Excel sheets, MATLAB scripts or even .NET assemblies. I think of something like a flowchart configurator in which you define the procedures via drag& drop using flow-statements (if-else, loops, etc.). Do you know of any systems heading in this direction?

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  • What have we lost from computers 20 years ago

    - by Martin Beckett
    Following the theme of - I can't believe computers used floppy disks and did you have debuggers 20 years ago - questions (and because even putting my age in hex I don't look young anymore). What have we lost from computers 20years ago? VMS versioning file system. Make a mistake, no problem myprog.cpp;5 is still there. Home computers that powered up to give you a wordprocessor or a basic prompt in <0.5sec User ports, serial ports and ADCs that you could control things with - without an arduino APIs that actually did what they said (even DOS interrupts), without having to guess and experiment your way through layers of frameworks.

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  • MVC Pattern, ViewModels, Location of conversion.

    - by Pino
    I've been working with ASP.Net MVC for around a year now and have created my applications in the following way. X.Web - MVC Application Contains Controller and Views X.Lib - Contains Data Access, Repositories and Services. This allows us to drop the .Lib into any application that requires it. At the moment we are using Entity Framework, the conversion from EntityO to a more specific model is done in the controller. This set-up means if a service method returns an EntityO and then the Controller will do a conversion before the data is passed to a view. I'm interested to know if I should move the conversion to the Service so that the app doesn't have Entity Objects being passed around.

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  • Are there too many qualified software development engineers chasing too few jobs?

    - by T Gregory
    I am trying to write this question in a non-argumentative way, but it is quite emotionally charged for some, so please bear with me. In the U.S., we hear constantly from CEOs that they cannot find enough qualified software engineers. In fact, it is the position of the U.S. government that demand for software engineering talent outpaces supply. This position can be clearly seen in the granting of tens of thousands of H1B visas, but also in the following excerpt from the official 2010-11 Bureau of Labor Statistics Occupational Outlook Handbook: Employment of computer software engineers is expected to increase by 32 percent from 2008-2018, which is much faster than the average for all occupations. In addition, this occupation will see a large number of new jobs, with more than 295,000 created between 2008 and 2018. Demand for computer software engineers will increase as computer networking continues to grow. For example, expanding Internet technologies have spurred demand for computer software engineers who can develop Internet, intranet, and World Wide Web applications. Likewise, electronic data-processing systems in business, telecommunications, healthcare, government, and other settings continue to become more sophisticated and complex. Implementing, safeguarding, and updating computer systems and resolving problems will fuel the demand for growing numbers of systems software engineers. New growth areas will also continue to arise from rapidly evolving technologies. The increasing uses of the Internet, the proliferation of Web sites, and mobile technology such as the wireless Internet have created a demand for a wide variety of new products. As more software is offered over the Internet, and as businesses demand customized software to meet their specific needs, applications and systems software engineers will be needed in greater numbers. In addition, the growing use of handheld computers will create demand for new mobile applications and software systems. As these devices become a larger part of the business environment, it will be necessary to integrate current computer systems with this new, more mobile technology. However, from the the employee side of the equation, we often hear the opposite. Many of the stories of SDEs with graduate degrees and decades of experience on the unemployment line, or the big tech interview war stories, are anecdotal, for sure. But, there is one piece of data that is neither anecdotal nor transitory, and that is the aggregate decisions of millions of undergraduates of what degree to pursue. Here, a different picture emerges from the data, and that picture is not good for the software profession. According the most recent Taulbee Survey from Computer Research Association, undergrad degree production in CS and CE has fallen nearly 60% since 2004. (Undergrad enrollments have ticked up in the past two years, but only modestly). Here we see that a basic disconnect between what corporate CEOs and the US government are saying and what potential employees really think about job prospects in software engineering. So my questions are these. Who are we to believe? Is there an acute talent shortage, or is there a long-term structural oversupply in the SDE labor market? Can anyone provide reliable data on long-term unemployment among SDEs? How many are leaving the profession due to lack of work? Real data is most helpful. Thanks.

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  • JavaScript or PHP based WYSIWYG vector based image editor

    - by Jeroen Pluimers
    For a PHP based site of a client, I'm looking for a vector based image editor that allows: end user creation of vectored images consisting of objects supports upload of bitmap images to be used as objects inside the vector image supports adding text objects to add to the vector image, and change properties (font name, font style, font size) of the text objects preferably supports layering or grouping of objects inside the vector image integrates nicely with a PHP based site (so a PHP or JavaScript library is preferred) can store the vector image in SVG, EPS or PDF Both commercial and FOSS solutions are OK. Any idea where to find such a library? --jeroen

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  • Scrum and Google Docs burndown chart

    - by Michal Minicki
    There is a tutorial on how to create a burndown chart for Scrum in the Google Docs application: http://www.scrumology.net/2011/05/03/how-to-create-a-burndown-chart-in-google-docs/ The problem I see with it though is, it has only a place to update progress once per sprint but the burndown is supposed to be updated with daily progress, right? How can one modify this chart to be able to put daily progress on it?

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  • Use a partial in a partial?

    - by Greg Wallace
    I'm a Rails newbie, so bear with me. I have a few places, some pages, some partials that use: <%= link_to "delete", post, method: :delete, data: { confirm: "You sure?" }, title: post.content %> Would it make sense to make this a partial since it is used repeatedly, sometimes in other partials too? Is it o.k. to put partials in partials?

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  • Different database for Membership and our web data or use just one?

    - by Jesus Rodriguez
    Is better to keep our Membership stuff on the DefaultConnection and create another connection (another database) for our data? Or just one database for all? If I have a MyAppContext and I want migrations for that context, It seems that I cannot have migrations for UserContext (In other words, I can just migrate one context) So, having two different databases I can migrate or the users (maybe membership migration is weird) or the web data. Or, I can mix the UserContext and MyAppContext in one UserAndAppContext and migrate all in one place, but this mixing also seems weird. What's the normal way to do this, one or two databases and what should be migrated?

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  • Is there any way to test how will the site perform under load

    - by Pankaj Upadhyay
    I have made an Asp.net MVC website and hosted it on a shared hosting provider. Since my website surrounds a very generic idea, it might have number of concurrent users sometime in future. So, I was thinking of a way to test my website for on-load performance. Like how will the site perform when 100 or 1000 users are online at the same time and surfing the website. This will also make me understand whether my LINQ queries are well written or not.

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  • Is there a very simple XML Editor/Viewer?

    - by Paul Spangle
    Part of our support job is to look at XML documents sent to our systems by our clients that have failed to load correctly. I do this by pasting the file in to Visual Studio as an XML file and VS colours it and adds line-breaks, indenting, etc. and it's then usually quite simple to spot the error and manually fix it and resubmit the document. Do I really have to use Visual Studio to do this? OK, it does the job quite well, but I'd have thought that something like Notepad++ would do the job just as well with a fraction of the machine resource usage. Is there are plugin for Notepad++ or another bit of freeware that can make XML look pretty and let me make simple edits?

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  • Compatibility of Enum Vs. string constants

    - by Yosi
    I was recently told that using Enum: public enum TaskEndState { Error, Completed, Running } may have compatibility/serialization issues, and thus sometimes it's better to use const string: public const string TASK_END_STATE = "END_STATE"; public const string TASK_END_STATE_ERROR = "TASK_END_STATE_ERROR"; public const string TASK_END_STATE_COMPLETE = "TASK_END_STATE_COMPLETE"; public const string TASK_END_STATE_RUNNING = "TASK_END_STATE_RUNNING"; Can you find practical use case where it may happen, is there any guidelines where Enum's should be avoided? Edit: My production environment has multiple WFC services (different versions of the same product). A later version may/or may not include some new properties as Task end state (this is just an example). If we try to deserialize a new Enum value in an older version of a specific service, it may not work.

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  • How can a large company foster excellence in its engineers?

    - by Joshiatto
    I am tasked with improving the skills (quality & speed) of engineers in my company. Here are some ideas: Pair Programming TDD Automated Check-in Policies Talks given by experts Awards for coding excellence Encourage competition among engineers to contribute to GitHub Publish standards and practices docs on the intranet site "Gamification" of engineering. Somehow make becoming badasses into a game they will enjoy playing Training Showcase github checkins on screens around the office Add an "engineer of the month" to the intranet home page How can I drive traffic to the intranet home page? What crazy futuristic idea would drive engineers to go to the page every day to see who of their peers are making more money than them (inferred via recognition) and then go off and improve their skills and productivity to see their standings improve on the home page??? Or any ideas just to foster collaboration and love for their jobs so they start taking more pride in their work?? Don't take my ideas as symptomatic of our org. I take full responsibility for not knowing the right way to do this.

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  • Codeigniter + JQuery + Processing.js to replace a Delphi App

    - by Peter Turner
    So, I've got a mandate to make our aged trillion lined Delphi app web based and it needs to make heavy use of the <canvas> element (HTML5 compatibility doesn't seem to be a big issue since we can just make our clients use a compatible browser the way we'd make them use a compatible version of Windows in the win32 environment). The Delphi app in question is almost completely database driven and will still pretty much continue to be developed as the main product. What I am tasked with is pretty much recreating a scaled down version of the program that performs the major functions of the whole program. I couldn't find any frameworks that simulate windows forms using the canvas element, I'm assuming this is probably by design since it is easier just to use HTML, well, be that as it may, I still think it would be cool to have a few of my cool controls on the web (TRichView and TVirtualTree, etc...) So my question is, to anyone who has tried this before, A.) What can we use for an IDE to code this web app (I just use emacs, but no one else in my company does)? B.) Is it a good idea to mix PHP and Processing.JS? It seems like I'm using a lot of AJAX to get anything to happen. 3 calls just for one dialog box to pop up, Loads the HTML for the dialog, Loads the XML to populate the database info on the form Loads the processing.js PJS file which draws the database info to the canvas. Is three a lot, do people usually combine all their gets into one?

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  • Best Design Pattern for Coupling User Interface Components and Data Structures

    - by szahn
    I have a windows desktop application with a tree view. Due to lack of a sound data-binding solution for a tree view, I've implemented my own layer of abstraction on it to bind nodes to my own data structure. The requirements are as follows: Populate a tree view with nodes that resemble fields in a data structure. When a node is clicked, display the appropriate control to modify the value of that property in the instance of the data structure. The tree view is populated with instances of custom TreeNode classes that inherit from TreeNode. The responsibility of each custom TreeNode class is to (1) format the node text to represent the name and value of the associated field in my data structure, (2) return the control used to modify the property value, (3) get the value of the field in the control (3) set the field's value from the control. My custom TreeNode implementation has a property called "Control" which retrieves the proper custom control in the form of the base control. The control instance is stored in the custom node and instantiated upon first retrieval. So each, custom node has an associated custom control which extends a base abstract control class. Example TreeNode implementation: //The Tree Node Base Class public abstract class TreeViewNodeBase : TreeNode { public abstract CustomControlBase Control { get; } public TreeViewNodeBase(ExtractionField field) { UpdateControl(field); } public virtual void UpdateControl(ExtractionField field) { Control.UpdateControl(field); UpdateCaption(FormatValueForCaption()); } public virtual void SaveChanges(ExtractionField field) { Control.SaveChanges(field); UpdateCaption(FormatValueForCaption()); } public virtual string FormatValueForCaption() { return Control.FormatValueForCaption(); } public virtual void UpdateCaption(string newValue) { this.Text = Caption; this.LongText = newValue; } } //The tree node implementation class public class ExtractionTypeNode : TreeViewNodeBase { private CustomDropDownControl control; public override CustomControlBase Control { get { if (control == null) { control = new CustomDropDownControl(); control.label1.Text = Caption; control.comboBox1.Items.Clear(); control.comboBox1.Items.AddRange( Enum.GetNames( typeof(ExtractionField.ExtractionType))); } return control; } } public ExtractionTypeNode(ExtractionField field) : base(field) { } } //The custom control base class public abstract class CustomControlBase : UserControl { public abstract void UpdateControl(ExtractionField field); public abstract void SaveChanges(ExtractionField field); public abstract string FormatValueForCaption(); } //The custom control generic implementation (view) public partial class CustomDropDownControl : CustomControlBase { public CustomDropDownControl() { InitializeComponent(); } public override void UpdateControl(ExtractionField field) { //Nothing to do here } public override void SaveChanges(ExtractionField field) { //Nothing to do here } public override string FormatValueForCaption() { //Nothing to do here return string.Empty; } } //The custom control specific implementation public class FieldExtractionTypeControl : CustomDropDownControl { public override void UpdateControl(ExtractionField field) { comboBox1.SelectedIndex = comboBox1.FindStringExact(field.Extraction.ToString()); } public override void SaveChanges(ExtractionField field) { field.Extraction = (ExtractionField.ExtractionType) Enum.Parse(typeof(ExtractionField.ExtractionType), comboBox1.SelectedItem.ToString()); } public override string FormatValueForCaption() { return string.Empty; } The problem is that I have "generic" controls which inherit from CustomControlBase. These are just "views" with no logic. Then I have specific controls that inherit from the generic controls. I don't have any functions or business logic in the generic controls because the specific controls should govern how data is associated with the data structure. What is the best design pattern for this?

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  • Does TDD lead to the good design?

    - by Eugen Martynov
    I'm in transition from "writing unit tests" state to TDD. I saw as Johannes Brodwall creates quite acceptable design from avoiding any of architecture phase before. I'll ask him soon if it was real improvisation or he had some thoughts upfront. I also clearly understand that everyone has experience that prevents to write explicit design bad patterns. But after participating in code retreat I hardly believe that writing test first could save us from mistakes. But I also believe that tests after code will lead to mistakes much faster. So this night question is asking for people who is using TDD for a long time share their experience about results of design without upfront thinking. If they really practice it and get mostly suitable design. Or it's my small understanding about TDD and probably agile.

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  • Is it possible to use RubyGnome2's/QtRuby's HTML renderers to make UI for a Ruby script?

    - by mjr
    I'd like to make a graphical user interface for my script, instead of running it from the console. I'm aware there's a wealth of UI libraries for Ruby, but I'm quite familiar with HTML and CSS and I'd like to use them for building an interface. So the question is: Is it possible to use a HTML rendering library to make such an UI? From what I understand, it's relatively easy to put in a HTML rendered view of something, but is it possible to communicate back with the script? Like when I push that big red button, it actually tells the script to act on it? Obviously it's possible if the script run on the server side, but I'd like to run it as a desktop application.

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  • How accurate is "Business logic should be in a service, not in a model"?

    - by Jeroen Vannevel
    Situation Earlier this evening I gave an answer to a question on StackOverflow. The question: Editing of an existing object should be done in repository layer or in service? For example if I have a User that has debt. I want to change his debt. Should I do it in UserRepository or in service for example BuyingService by getting an object, editing it and saving it ? My answer: You should leave the responsibility of mutating an object to that same object and use the repository to retrieve this object. Example situation: class User { private int debt; // debt in cents private string name; // getters public void makePayment(int cents){ debt -= cents; } } class UserRepository { public User GetUserByName(string name){ // Get appropriate user from database } } A comment I received: Business logic should really be in a service. Not in a model. What does the internet say? So, this got me searching since I've never really (consciously) used a service layer. I started reading up on the Service Layer pattern and the Unit Of Work pattern but so far I can't say I'm convinced a service layer has to be used. Take for example this article by Martin Fowler on the anti-pattern of an Anemic Domain Model: There are objects, many named after the nouns in the domain space, and these objects are connected with the rich relationships and structure that true domain models have. The catch comes when you look at the behavior, and you realize that there is hardly any behavior on these objects, making them little more than bags of getters and setters. Indeed often these models come with design rules that say that you are not to put any domain logic in the the domain objects. Instead there are a set of service objects which capture all the domain logic. These services live on top of the domain model and use the domain model for data. (...) The logic that should be in a domain object is domain logic - validations, calculations, business rules - whatever you like to call it. To me, this seemed exactly what the situation was about: I advocated the manipulation of an object's data by introducing methods inside that class that do just that. However I realize that this should be a given either way, and it probably has more to do with how these methods are invoked (using a repository). I also had the feeling that in that article (see below), a Service Layer is more considered as a façade that delegates work to the underlying model, than an actual work-intensive layer. Application Layer [his name for Service Layer]: Defines the jobs the software is supposed to do and directs the expressive domain objects to work out problems. The tasks this layer is responsible for are meaningful to the business or necessary for interaction with the application layers of other systems. This layer is kept thin. It does not contain business rules or knowledge, but only coordinates tasks and delegates work to collaborations of domain objects in the next layer down. It does not have state reflecting the business situation, but it can have state that reflects the progress of a task for the user or the program. Which is reinforced here: Service interfaces. Services expose a service interface to which all inbound messages are sent. You can think of a service interface as a façade that exposes the business logic implemented in the application (typically, logic in the business layer) to potential consumers. And here: The service layer should be devoid of any application or business logic and should focus primarily on a few concerns. It should wrap Business Layer calls, translate your Domain in a common language that your clients can understand, and handle the communication medium between server and requesting client. This is a serious contrast to other resources that talk about the Service Layer: The service layer should consist of classes with methods that are units of work with actions that belong in the same transaction. Or the second answer to a question I've already linked: At some point, your application will want some business logic. Also, you might want to validate the input to make sure that there isn't something evil or nonperforming being requested. This logic belongs in your service layer. "Solution"? Following the guidelines in this answer, I came up with the following approach that uses a Service Layer: class UserController : Controller { private UserService _userService; public UserController(UserService userService){ _userService = userService; } public ActionResult MakeHimPay(string username, int amount) { _userService.MakeHimPay(username, amount); return RedirectToAction("ShowUserOverview"); } public ActionResult ShowUserOverview() { return View(); } } class UserService { private IUserRepository _userRepository; public UserService(IUserRepository userRepository) { _userRepository = userRepository; } public void MakeHimPay(username, amount) { _userRepository.GetUserByName(username).makePayment(amount); } } class UserRepository { public User GetUserByName(string name){ // Get appropriate user from database } } class User { private int debt; // debt in cents private string name; // getters public void makePayment(int cents){ debt -= cents; } } Conclusion All together not much has changed here: code from the controller has moved to the service layer (which is a good thing, so there is an upside to this approach). However this doesn't look like it had anything to do with my original answer. I realize design patterns are guidelines, not rules set in stone to be implemented whenever possible. Yet I have not found a definitive explanation of the service layer and how it should be regarded. Is it a means to simply extract logic from the controller and put it inside a service instead? Is it supposed to form a contract between the controller and the domain? Should there be a layer between the domain and the service layer? And, last but not least: following the original comment Business logic should really be in a service. Not in a model. Is this correct? How would I introduce my business logic in a service instead of the model?

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  • Java - learning / migrating fast

    - by Yippie-Kai-Yay
    This is not one of those questions like "How do I learn Java extremely fast, I know nothing about programming, but I heard Java is cool, yo". I have an interview for a Java Software Developer in a couple of weeks and the thing is that I think that I know C++ really good and I am somewhat good at C# (like, here I can probably answer on a lot of questions related to these languages), but I have almost zero experience with Java. I have a lot of projects written in both languages, I participiated in several open-source projects (mostly C++, though). Now, what should I do (in your opinion) to prepare myself for this Java interview. I guess migrating from C# to Java should be kind of fast, especially when you know a lot about programming in global, patterns, modern techniques and have a lot of practical experience behind you. But still two weeks is obviously not enough to get Java in-depth - so what should I focus on to have the best chances to pass the interview? Thank you.

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