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  • What is the best book for the preparation of MCPD Exam 70-564 (Designing and Developing ASP.NET 3.5 Applications)?

    - by Steve Johnson
    Hi all, I have seen a couple of questions like this one and scanned through the answers but somehow the replies were not satisfactory or practical. So i wondered maybe people who have gone through it and may suggest a better approach for the preparation of this exam. Goal: My goal is actually NOT merely to pass that exam. I intend to actually master the skill. I have been into asp.net web development for approximately 1.5 years and I want to study something that really improves "Design and Development Skills" in Web Development in general and asp.net to be specific which i can put to use and build upon that. Please suggest a book that teaches professional Asp.Net design and development skills and approaches to quality development by taking through practice design scenarios and their solutions and through various case studies that involve design problems and their implemented solutions. Edit: I have found the Micorosoft training kits to be fairly interesting and helpful as these tend to increase knowledge. I have utilized a lot of things after getting a good explanation of things from the training kits. However, as far as Microsoft Training Kit for 70-564 is concerned, there are not a lot of good reviews about it. What i have read and searched on the net , the reviews on amazon and various forums, stack-exchange and experts-exchange, were more inclined to the conclusion that "Microsoft Training Kit for Exam 70-564 is not good. Its is not good as compared to other kits from Microsoft, like as compared to the training kit of Exam 70-562 or others." So i was looking for a proper book containing examples from practical world scenarios and case studies from which i can not only learn but also master the skills before wasting money of Microsoft Training Kit for Exam 70-564. Waiting for experts to provide a suitable advice.

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  • Any recommended books/resources on component-based design?

    - by user1163640
    I come from a background with heavy use of the classical object-oriented paradigm for software development. The company I am a part of switched to Unity not too long ago, and we're all very excited to get started using it However, one aspect that have sparked my interested, and which I think will become a very important part of our future development, is Unity's approach to component-based design with scripting; with less focus on typical hierarchical aspect. Question I was wondering if anyone could recommend any good books on this subject? I have had trouble finding any books or books with reliable reviews, and was wondering if anyone more experienced here had something to say on the issue? Any other kind of resource would be excellent too, I'm just interested in getting to learn everything I can about it. This is not meant as a discussion about best books or resources on the topic, but simply a question regarding any resources that any of you find useful. Thank you all for your time!

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  • Business Layer Design in J2EE Project

    - by user63157
    Currently the project on which I am working is being developed with Spring, Hibernate and struts. The business layer consists of simple java beans with no behavior in them only properties and getter and setter methods, the services are written on them which operates on them and call DAO layer methods and all. My questions is that is it object oriented way of designing or simply the procedure way in which the data and the functions on which they operate are not together. Please provide your thoughts and inputs on how the business logic is design and implemented in j2ee application, is the domain model contains business methods or are they simply dumb objects which have only data and services written on to them.

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  • How to maintain an ordered table with Core Data (or SQL) with insertions/deletions?

    - by Jean-Denis Muys
    This question is in the context of Core Data, but if I am not mistaken, it applies equally well to a more general SQL case. I want to maintain an ordered table using Core Data, with the possibility for the user to: reorder rows insert new lines anywhere delete any existing line What's the best data model to do that? I can see two ways: 1) Model it as an array: I add an int position property to my entity 2) Model it as a linked list: I add two one-to-one relations, next and previous from my entity to itself 1) makes it easy to sort, but painful to insert or delete as you then have to update the position of all objects that come after 2) makes it easy to insert or delete, but very difficult to sort. In fact, I don't think I know how to express a Sort Descriptor (SQL ORDER BY clause) for that case. Now I can imagine a variation on 1): 3) add an int ordering property to the entity, but instead of having it count one-by-one, have it count 100 by 100 (for example). Then inserting is as simple as finding any number between the ordering of the previous and next existing objects. The expensive renumbering only has to occur when the 100 holes have been filled. Making that property a float rather than an int makes it even better: it's almost always possible to find a new float midway between two floats. Am I on the right track with solution 3), or is there something smarter?

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  • Repository Design Pattern Guidance

    - by thefactor
    Let's say you have an MVVM CRM application. You have a number of customer objects in memory, through a repository. What would be the appropriate place to handle tasks that aren't associated with traditional MVVM tasks from a GUI? For example, let's say every few minutes you want to check to see if their address is valid and pop up a notification if it is not. Or you want to send out an hourly e-mail update. Or you want a window to pop up to remind you to call a customer at a specific time. Where does this logic go? It's not GUI/action-oriented, and it's not logic that would be appropriate for a repository, I think.

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  • Are document-oriented databases any more suitable than relational ones for persisting objects?

    - by Owen Fraser-Green
    In terms of database usage, the last decade was the age of the ORM with hundreds competing to persist our object graphs in plain old-fashioned RMDBS. Now we seem to be witnessing the coming of age of document-oriented databases. These databases are highly optimized for schema-free documents but are also very attractive for their ability to scale out and query a cluster in parallel. Document-oriented databases also hold a couple of advantages over RDBMS's for persisting data models in object-oriented designs. As the tables are schema-free, one can store objects belonging to different classes in an inheritance hierarchy side-by-side. Also, as the domain model changes, so long as the code can cope with getting back objects from an old version of the domain classes, one can avoid having to migrate the whole database at every change. On the other hand, the performance benefits of document-oriented databases mainly appear to come about when storing deeper documents. In object-oriented terms, classes which are composed of other classes, for example, a blog post and its comments. In most of the examples of this I can come up with though, such as the blog one, the gain in read access would appear to be offset by the penalty in having to write the whole blog post "document" every time a new comment is added. It looks to me as though document-oriented databases can bring significant benefits to object-oriented systems if one takes extreme care to organize the objects in deep graphs optimized for the way the data will be read and written but this means knowing the use cases up front. In the real world, we often don't know until we actually have a live implementation we can profile. So is the case of relational vs. document-oriented databases one of swings and roundabouts? I'm interested in people's opinions and advice, in particular if anyone has built any significant applications on a document-oriented database.

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  • How Oracle Data Integration Customers Differentiate Their Business in Competitive Markets

    - by Irem Radzik
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 With data being a central force in driving innovation and competing effectively, data integration has become a key IT approach to remove silos and ensure working with consistent and trusted data. Especially with the release of 12c version, Oracle Data Integrator and Oracle GoldenGate offer easy-to-use and high-performance solutions that help companies with their critical data initiatives, including big data analytics, moving to cloud architectures, modernizing and connecting transactional systems and more. In a recent press release we announced the great momentum and analyst recognition Oracle Data Integration products have achieved in the data integration and replication market. In this press release we described some of the key new features of Oracle Data Integrator 12c and Oracle GoldenGate 12c. In addition, a few from our 4500+ customers explained how Oracle’s data integration platform helped them achieve their business goals. In this blog post I would like to go over what these customers shared about their experience. Land O’Lakes is one of America’s premier member-owned cooperatives, and offers an extensive line of agricultural supplies, as well as production and business services. Rich Bellefeuille, manager, ETL & data warehouse for Land O’Lakes told us how GoldenGate helped them modernize their critical ERP system without impacting service and how they are moving to new projects with Oracle Data Integrator 12c: “With Oracle GoldenGate 11g, we've been able to migrate our enterprise-wide implementation of Oracle’s JD Edwards EnterpriseOne, ERP system, to a new database and application server platform with minimal downtime to our business. Using Oracle GoldenGate 11g we reduced database migration time from nearly 30 hours to less than 30 minutes. Given our quick success, we are considering expansion of our Oracle GoldenGate 12c footprint. We are also in the midst of deploying a solution leveraging Oracle Data Integrator 12c to manage our pricing data to handle orders more effectively and provide a better relationship with our clients. We feel we are gaining higher productivity and flexibility with Oracle's data integration products." ICON, a global provider of outsourced development services to the pharmaceutical, biotechnology and medical device industries, highlighted the competitive advantage that a solid data integration foundation brings. Diarmaid O’Reilly, enterprise data warehouse manager, ICON plc said “Oracle Data Integrator enables us to align clinical trials intelligence with the information needs of our sponsors. It helps differentiate ICON’s services in an increasingly competitive drug-development industry."  You can find more info on ICON's implementation here. A popular use case for Oracle GoldenGate’s real-time data integration is offloading operational reporting from critical transaction processing systems. SolarWorld, one of the world’s largest solar-technology producers and the largest U.S. solar panel manufacturer, implemented Oracle GoldenGate for real-time data integration of manufacturing data for fast analysis. Russ Toyama, U.S. senior database administrator for SolarWorld told us real-time data helps their operations and GoldenGate’s solution supports high performance of their manufacturing systems: “We use Oracle GoldenGate for real-time data integration into our decision support system, which performs real-time analysis for manufacturing operations to continuously improve product quality, yield and efficiency. With reliable and low-impact data movement capabilities, Oracle GoldenGate also helps ensure that our critical manufacturing systems are stable and operate with high performance."  You can watch the full interview with SolarWorld's Russ Toyama here. Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Starwood Hotels and Resorts is one of the many customers that found out how well Oracle Data Integration products work with Oracle Exadata. Gordon Light, senior director of information technology for StarWood Hotels, says they had notable performance gain in loading Oracle Exadata reporting environment: “We leverage Oracle GoldenGate to replicate data from our central reservations systems and other OLTP databases – significantly decreasing the overall ETL duration. Moving forward, we plan to use Oracle GoldenGate to help the company achieve near-real-time reporting.”You can listen about Starwood Hotels' implementation here. Many companies combine the power of Oracle GoldenGate with Oracle Data Integrator to have a single, integrated data integration platform for variety of use cases across the enterprise. Ufone is another good example of that. The leading mobile communications service provider of Pakistan has improved customer service using timely customer data in its data warehouse. Atif Aslam, head of management information systems for Ufone says: “Oracle Data Integrator and Oracle GoldenGate help us integrate information from various systems and provide up-to-date and real-time CRM data updates hourly, rather than daily. The applications have simplified data warehouse operations and allowed business users to make faster and better informed decisions to protect revenue in the fast-moving Pakistani telecommunications market.” You can read more about Ufone's use case here. In our Oracle Data Integration 12c launch webcast back in November we also heard from BT’s CTO Surren Parthab about their use of GoldenGate for moving to private cloud architecture. Surren also shared his perspectives on Oracle Data Integrator 12c and Oracle GoldenGate 12c releases. You can watch the video here. These are only a few examples of leading companies that have made data integration and real-time data access a key part of their data governance and IT modernization initiatives. They have seen real improvements in how their businesses operate and differentiate in today’s competitive markets. You can read about other customer examples in our Ebook: The Path to the Future and access resources including white papers, data sheets, podcasts and more via our Oracle Data Integration resource kit. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • Accommodating hierarchical data in SQL Server 2005 database design

    - by Remnant
    Context I am fairly new to database design (=know the basics) and am grappling with how best to design my database for a project I am currently working on. In short, my database will keep a log of which employees have attended certain health and safety courses throughout the year. There are multiple types of course e.g. moving objects, fire safety, hygiene etc. In terms of my database design I need to accommodate the following: Each location can have multiple divisions Each division can have multiple departments Each department can have multiple functions Each function can have multiple job roles Each job role can have different course requirements Also note that the structure at each location may not be the same e.g. the departments within divisions are not the same across locations and the functions within departments may also differ. Edit - updated to better articulate problem Let's assume I am just looking at Location, Division and Department and I have my database as follows: LocationTable DivisionTable DepartmentTable LocationID(PK) DivisionID(PK) DepartmentID(PK) LocationName DivisionName DepartmentName There is a many-to-many relationship between Locations and Divisions and also between Departments and Divisions. Suppose I set up a 'Junction Table' as follows: Location_Division LocationID(FK) DivisionID(FK) Using Location_Division I could easily pull back the Divisions for any Location. However, suppose I want to pull back all departments for a given Division in a given Location. If I set up another 'Junction Table' for Division and Department then I can't see how I would differentiate Division by Location? Division_Department DivisionID(FK) DepartmentID(FK) Location_Division Division_Department LocationID DivisionID DivisionID DepartmentID 1 1 1 1 1 2 1 2 2 1 2 1 2 2 2 2 Do I need to expand the number of columns in my 'Junction Table' e.g. Location_Division_Department LocationID(FK) DivisionID(FK) DepartmentID(FK) Location_Division_Department LocationID DivisionID DepartmentID 1 1 1 1 1 2 1 1 3 2 1 1 2 1 2 2 1 3

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  • database design - empty fields

    - by imanc
    Hey, I am currently debating an issue with a guy on my dev team. He believes that empty fields are bad news. For instance, if we have a customer details table that stores data for customers from different countries, and each country has a slightly different address configuration - plus 1-2 extra fields, e.g. French customer details may also store details for entry code, and floor/level plus title fields (madamme, etc.). South Africa would have a security number. And so on. Given that we're talking about minor variances my idea is to put all of the fields into the table and use what is needed on each form. My colleague believes we should have a separate table with extra data. E.g. customer_info_fr. But this seams to totally defeat the purpose of a combined table in the first place. His argument is that empty fields / columns is bad - but I'm struggling to find justification in terms of database design principles for or against this argument and preferred solutions. Another option is a separate mini EAV table that stores extra data with parent_id, key, val fields. Or to serialise extra data into an extra_data column in the main customer_data table. I think I am confused because what I'm discussing is not covered by 3NF which is what I would typically use as a reference for how to structure data. So my question specifically: - if you have slight variances in data for each record (1-2 different fields for instance) what is the best way to proceed?

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  • SSIS Design Pattern: Loading Variable-Length Rows

    - by andyleonard
    Introduction I encounter flat file sources with variable-length rows on occassion. Here, I supply one SSIS Design Pattern for loading them. What's a Variable-Length Row Flat File? Great question - let's start with a definition. A variable-length row flat file is a text source of some flavor - comma-separated values (CSV), tab-delimited file (TDF), or even fixed-length, positional-, or ordinal-based (where the location of the data on the row defines its field). The major difference between a "normal"...(read more)

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  • The right way to start out in game development/design [closed]

    - by Marco Sacristão
    Greetings everyone I'm a 19 year old student looking for some help in the field of game development. This question may or may not seem a bit overused, but the fact is that game development has been my life long dream, and after several hours of search I've realized that I've been going in circles for the past three or four months whilst doing such research on how to really get down and dirty with game development, therefor I decided to ask you guys if you could help me out at all. Let me start off with some information about me and things i've already learned about GameDev which might help you out on helping me out (wordplay!): I'm not an expert programmer, but I do have knowledge on how to program in several languages including C and Java (Currently learning Java in my degree in Computer Engineering), but my methodology might not be most correct in terms of syntax (hence my difficulty in starting out, i'm afraid that the starting point might not be the most correct, and it would deploy a wrongful development methodology that would be to corrected later on, in terms of game development or other projects). I have yet to work in a project as large as a game, never in my learning curve of programming I've done a project to the scale of a video game, only very small software (PHP Front-ends and Back-ends, with some basic JQuery and CSS knowledge). I'm not the biggest mathematician or physicist, but I already know that is not a problem, because there are several game engines already available for use and integration with home-made projects (Box2D, etc). I've also learned about some libraries that could be included in said projects, to ease out some process in game development, like SDL for example. I do not know how sprites, states, particles or any specific game-related techniques work. With that being said, you can see that I have some ideas on game development, but I have absolutely no clue on how to design and produce a game, or even how game-like mechanics work. It does not have to be a complex game just to start out, I'd rather learn the basic of game design (Like 2D drawing, tiling, object collision) and test that out in a language that I feel comfortable in which could be later on migrated to other platforms, as long that what I've learned is the correct way to do things, and not just something that I've learned from some guy on Youtube by replicating that code on the video. I'm sorry if my question is not in the best format possible, but I've got so many questions on my mind that are still un-answered that I don't know were to start! Thank you for reading.

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  • 5 Mac Applications For Web And Graphic Design

    - by Jyoti
    In this article free applications useful and effective for the development and creation of websites with your Mac computer. Without further ado, here are 5 Excellent Mac Application for Web and Graphic Design. Fotoflexer : Fotoflexer claims to be “The world’s most advanced online image editor”. It offers completely free access to numerous features such as [...]

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  • how to evaluate own project

    - by gruszczy
    I am working on a open source project in pure C, that I have started some time ago, but only recently found time to add some features. I can clearly some weaknesses of my old design, so I am trying to refactor my old code. I have no idea however, how to evaluate properly my new code. Do you know about any techniques or tools for code evaluation? I am pretty good with object oriented design, but for about three years I had no contact with purely structural one. Therefore I don't have enough experience, to be able to discern between good and bad design choices.

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  • Central Exception Handler

    - by J-unior
    Recently I've been thinking about a general ExceptionHandler, that I could initialize once in my app context and inject it everywhere. The idea that it will have quite simple interface with just public void handle(Exception ex), and then according to exception type it should decide what to do, maybe just log it, or show an alert message to the user, or maybe kill the whole app. The question is, what is the prettiest way to write such handler without lots of instanceofs? Unfortunately googling gives me only the default exception handler for RuntimeException that was introduced in Java 5. My first idea is to create an enum, that will have Class field for exception type and it will return the appropriate execution point, for example a concrete exception handler that also implements the interface public void handle(Exception ex), but with the required casting already.

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  • Rule of thumb for enemy art design in 2D platformer

    - by Terrance
    I'm at the early stages of developing a 2D side scrolling open ended platformer (think Metroidvania) and am having a bit of difficulty at enemy design inspiration for something of a scifi, nature, fantasy setting that isn't overly familar or obvious. I haven't seen too many articles, blogs or books that talk about the subject at great length. Is there a fair rule of thumb when coming up with enemy art with respect to keeping your player engaged?

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  • Why is it a good practice to wrap all primitives and Strings?

    - by Amogh Talpallikar
    According to Jeff Bay's Essay on Object Callisthenics, One of the practices is set to be "Wrap all primitives and Strings" Can anyone elaborate on this ? In languages where we already have wrappers for primitives like C# and Java. and In languages where Collections can have generics where you are sure of what type goes into the collection, do we need to wrap string's inside their own classes ? Does it have any other advantage ?

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  • Wrappers/law of demeter seems to be an anti-pattern...

    - by Robert Fraser
    I've been reading up on this "Law of Demeter" thing, and it (and pure "wrapper" classes in general) seem to generally be anti patterns. Consider an implementation class: class Foo { void doSomething() { /* whatever */ } } Now consider two different implementations of another class: class Bar1 { private static Foo _foo = new Foo(); public static Foo getFoo() { return _foo; } } class Bar2 { private static Foo _foo = new Foo(); public static void doSomething() { _foo.doSomething(); } } And the ways to call said methods: callingMethod() { Bar1.getFoo().doSomething(); // Version 1 Bar2.doSomething(); // Version 2 } At first blush, version 1 seems a bit simpler, and follows the "rule of Demeter", hide Foo's implementation, etc, etc. But this ties any changes in Foo to Bar. For example, if a parameter is added to doSomething, then we have: class Foo { void doSomething(int x) { /* whatever */ } } class Bar1 { private static Foo _foo = new Foo(); public static Foo getFoo() { return _foo; } } class Bar2 { private static Foo _foo = new Foo(); public static void doSomething(int x) { _foo.doSomething(x); } } callingMethod() { Bar1.getFoo().doSomething(5); // Version 1 Bar2.doSomething(5); // Version 2 } In both versions, Foo and callingMethod need to be changed, but in Version 2, Bar also needs to be changed. Can someone explain the advantage of having a wrapper/facade (with the exception of adapters or wrapping an external API or exposing an internal one).

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  • Circular dependency and object creation when attempting DDD

    - by Matthew
    I have a domain where an Organization has People. Organization Entity public class Organization { private readonly List<Person> _people = new List<Person>(); public Person CreatePerson(string name) { var person = new Person(organization, name); _people.Add(person); return person; } public IEnumerable<Person> People { get { return _people; } } } Person Entity public class Person { public Person(Organization organization, string name) { if (organization == null) { throw new ArgumentNullException("organization"); } Organization = organization; Name = name; } public Organization { get; private set; } public Name { get; private set; } } The rule for this relationship is that a Person must belong to exactly one Organization. The invariants I want to guarantee are: A person must have an organization this is enforced via the Person's constuctor An organization must know of its people this is why the Organization has a CreatePerson method A person must belong to only one organization this is why the organization's people list is not publicly mutable (ignoring the casting to List, maybe ToEnumerable can enforce that, not too concerned about it though) What I want out of this is that if a person is created, that the organization knows about its creation. However, the problem with the model currently is that you are able to create a person without ever adding it to the organizations collection. Here's a failing unit-test to describe my problem [Test] public void AnOrganizationMustKnowOfItsPeople() { var organization = new Organization(); var person = new Person(organization, "Steve McQueen"); CollectionAssert.Contains(organization.People, person); } What is the most idiomatic way to enforce the invariants and the circular relationship?

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  • Why is permadeath essential to a roguelike design?

    - by Gregory Weir
    Roguelikes and roguelike-likes (Spelunky, The Binding of Isaac) tend to share a number of game design elements: Procedurally generated worlds Character growth by way of new abilities and powers Permanent death I can understand why starting with permadeath as a premise would lead you to the other ideas: if you're going to be starting over a lot, you'll want variety in your experiences. But why do the first two elements imply a permadeath approach?

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  • Is it a good practice to wrap all primitives and Strings?

    - by Amogh Talpallikar
    According to Jeff Bay's Essay on Object Callisthenics, One of the practices is set to be "Wrap all primitives and Strings" Can anyone elaborate on this ? In languages where we already have wrappers for primitives like C# and Java. and In languages where Collections can have generics where you are sure of what type goes into the collection, do we need to wrap string's inside their own classes ? Does it have any other advantage ?

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  • When should a method of a class return the same instance after modifying itself?

    - by modiX
    I have a class that has three methods A(), B() and C(). Those methods modify the own instance. While the methods have to return an instance when the instance is a separate copy (just as Clone()), I got a free choice to return void or the same instance (return this;) when modifying the same instance in the method and not returning any other value. When deciding for returning the same modified instance, I can do neat method chains like obj.A().B().C();. Would this be the only reason for doing so? Is it even okay to modify the own instance and return it, too? Or should it only return a copy and leave the original object as before? Because when returning the same modified instance the user would maybe admit the returned value is a copy, otherwise it would not be returned? If it's okay, what's the best way to clarify such things on the method?

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  • LSP vs OCP / Liskov Substitution VS Open Close

    - by Kolyunya
    I am trying to understand the SOLID principles of OOP and I've come to the conclusion that LSP and OCP have some similarities (if not to say more). the open/closed principle states "software entities (classes, modules, functions, etc.) should be open for extension, but closed for modification". LSP in simple words states that any instance of Foo can be replaced with any instance of Bar which is derived from Foo and the program will work the same very way. I'm not a pro OOP programmer, but it seems to me that LSP is only possible if Bar, derived from Foo does not change anything in it but only extends it. That means that in particular program LSP is true only when OCP is true and OCP is true only if LSP is true. That means that they are equal. Correct me if I'm wrong. I really want to understand these ideas. Great thanks for an answer.

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  • Removing hard-coded values and defensive design vs YAGNI

    - by Ben Scott
    First a bit of background. I'm coding a lookup from Age - Rate. There are 7 age brackets so the lookup table is 3 columns (From|To|Rate) with 7 rows. The values rarely change - they are legislated rates (first and third columns) that have stayed the same for 3 years. I figured that the easiest way to store this table without hard-coding it is in the database in a global configuration table, as a single text value containing a CSV (so "65,69,0.05,70,74,0.06" is how the 65-69 and 70-74 tiers would be stored). Relatively easy to parse then use. Then I realised that to implement this I would have to create a new table, a repository to wrap around it, data layer tests for the repo, unit tests around the code that unflattens the CSV into the table, and tests around the lookup itself. The only benefit of all this work is avoiding hard-coding the lookup table. When talking to the users (who currently use the lookup table directly - by looking at a hard copy) the opinion is pretty much that "the rates never change." Obviously that isn't actually correct - the rates were only created three years ago and in the past things that "never change" have had a habit of changing - so for me to defensively program this I definitely shouldn't store the lookup table in the application. Except when I think YAGNI. The feature I am implementing doesn't specify that the rates will change. If the rates do change, they will still change so rarely that maintenance isn't even a consideration, and the feature isn't actually critical enough that anything would be affected if there was a delay between the rate change and the updated application. I've pretty much decided that nothing of value will be lost if I hard-code the lookup, and I'm not too concerned about my approach to this particular feature. My question is, as a professional have I properly justified that decision? Hard-coding values is bad design, but going to the trouble of removing the values from the application seems to violate the YAGNI principle. EDIT To clarify the question, I'm not concerned about the actual implementation. I'm concerned that I can either do a quick, bad thing, and justify it by saying YAGNI, or I can take a more defensive, high-effort approach, that even in the best case ultimately has low benefits. As a professional programmer does my decision to implement a design that I know is flawed simply come down to a cost/benefit analysis?

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  • How important is Programming for a Level Designer?

    - by WryGrin
    I'm currently attending school in a Level Design program, and I was wondering how important programming really is in being a Level Designer? I'm apparently incapable of learning programming (despite my best efforts), and tend to do very well in all other courses 3D modelling, story/character design, narrative and dialogue writing, environmental and conceptual design etc. I'm wondering if my strengths in the other areas are enough (with practice) to let me become a Level Designer, or I'm wasting my time if I can't program? I really want to be a Designer, but I just can't seem to wrap my head around the "language" of programming in general (Java kicks my teeth in even with tutoring and additional work on my own).

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  • Design pattern for an ASP.NET project using Entity Framework

    - by MPelletier
    I'm building a website in ASP.NET (Web Forms) on top of an engine with business rules (which basically resides in a separate DLL), connected to a database mapped with Entity Framework (in a 3rd, separate project). I designed the Engine first, which has an Entity Framework context, and then went on to work on the website, which presents various reports. I believe I made a terrible design mistake in that the website has its own context (which sounded normal at first). I present this mockup of the engine and a report page's code behind: Engine (in separate DLL): public Engine { DatabaseEntities _engineContext; public Engine() { // Connection string and procedure managed in DB layer _engineContext = DatabaseEntities.Connect(); } public ChangeSomeEntity(SomeEntity someEntity, int newValue) { //Suppose there's some validation too, non trivial stuff SomeEntity.Value = newValue; _engineContext.SaveChanges(); } } And report: public partial class MyReport : Page { Engine _engine; DatabaseEntities _webpageContext; public MyReport() { _engine = new Engine(); _databaseContext = DatabaseEntities.Connect(); } public void ChangeSomeEntityButton_Clicked(object sender, EventArgs e) { SomeEntity someEntity; //Wrong way: //Get the entity from the webpage context someEntity = _webpageContext.SomeEntities.Single(s => s.Id == SomeEntityId); //Send the entity from _webpageContext to the engine _engine.ChangeSomeEntity(someEntity, SomeEntityNewValue); // <- oops, conflict of context //Right(?) way: //Get the entity from the engine context someEntity = _engine.GetSomeEntity(SomeEntityId); //undefined above //Send the entity from the engine's context to the engine _engine.ChangeSomeEntity(someEntity, SomeEntityNewValue); // <- oops, conflict of context } } Because the webpage has its own context, giving the Engine an entity from a different context will cause an error. I happen to know not to do that, to only give the Engine entities from its own context. But this is a very error-prone design. I see the error of my ways now. I just don't know the right path. I'm considering: Creating the connection in the Engine and passing it off to the webpage. Always instantiate an Engine, make its context accessible from a property, sharing it. Possible problems: other conflicts? Slow? Concurrency issues if I want to expand to AJAX? Creating the connection from the webpage and passing it off to the Engine (I believe that's dependency injection?) Only talking through ID's. Creates redundancy, not always practical, sounds archaic. But at the same time, I already recuperate stuff from the page as ID's that I need to fetch anyways. What would be best compromise here for safety, ease-of-use and understanding, stability, and speed?

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