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  • ASP.NET MVC: post-redirect-get pattern, with only two overloaded action methods

    - by Rafi
    Is it possible to implement post-redirect-get pattern, with two overloaded action methods(One for GET action and the other for POST action) in ASP.NET MVC. In all of the MVC post-redirect-get pattern samples, I have seen three different action methods for the post-redirect-get process, each having different names. Is this really required? For Eg:(Does the code shown below, follows Post-Redirect-Get pattern?) public class SalaryTransferController : Controller { // // GET: /SalaryTransfer/ [HttpGet] public ActionResult Index(int id) { SalaryTransferIndexViewModel vm = new SalaryTransferIndexViewModel(id) { SelectedDivision = DivisionEnum.Contracting }; //Do some processing here return View(vm); } // // POST: /SalaryTransfer/ [HttpPost] public ActionResult Index(SalaryTransferIndexViewModel vm) { bool validationsuccess = false; //validate if (validationsuccess) return RedirectToAction("Index", new {id=1234 }); else return View(vm); } } Thank you for your responses.

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  • Risking the exception anti-pattern.. with some modifications

    - by Sridhar Iyer
    Lets say that I have a library which runs 24x7 on certain machines. Even if the code is rock solid, a hardware fault can sooner or later trigger an exception. I would like to have some sort of failsafe in position for events like this. One approach would be to write wrapper functions that encapsulate each api a: returnCode=DEFAULT; try { returnCode=libraryAPI1(); } catch(...) { returnCode=BAD; } return returnCode; The caller of the library then restarts the whole thread, reinitializes the module if the returnCode is bad. Things CAN go horribly wrong. E.g. if the try block(or libraryAPI1()) had: func1(); char *x=malloc(1000); func2(); if func2() throws an exception, x will never be freed. On a similar vein, file corruption is a possible outcome. Could you please tell me what other things can possibly go wrong in this scenario?

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  • Do I have to create a static library to test my application?

    - by Christopher Gateley
    I'm just getting started with TDD and am curious as to what approaches others take to run their tests. For reference, I am using the google testing framework, but I believe the question is applicable to most other testing frameworks and to languages other than C/C++. My general approach so far has been to do either one of three things: Write the majority of the application in a static library, then create two executables. One executable is the application itself, while the other is the test runner with all of the tests. Both link to the static library. Embed the testing code directly into the application itself, and enable or disable the testing code using compiler flags. This is probably the best approach I've used so far, but clutters up the code a bit. Embed the testing code directly into the application itself, and, given certain command-line switches either run the application itself or run the tests embedded in the application. None of these solutions are particularly elegant... How do you do it?

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  • What is the best solution to do Reporting on Object data for .NET ?

    - by Peter Fox
    Hi, Our projects are using objects as the data source to reports. Our business layer is returning single objects or IEnumerable. Our reports (quite complex) need to display value-type properties of the object, and its related objects. Typical case would be, from a List, display a master report with category data, then a subreport with data for each Product inside each Category, then a subreport for each Part of each Product, and so on. Reporting from the database is not an option for us. We have tried so far - Reporting Services : works but have to mess around with the XML definition of the report to define the datasource classes, very hard to work with if you use an object datasource, architecturally not too clean - Telerik Reports : quite nice (esp., nice architecture) but seems to have problems with complex reports (master/sub), does not give great paging control, rumored to have performance/crash problems (immature product). Does anyone know a good reporting solution that can be integrated in an ASP.NET application and works well with objects as datasources ?

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  • Delegates in Action -Help

    - by Amutha
    I am learning delegates.I am very curious to apply delegates to the following chain-of-responsibility pattern. Kindly help me the way to apply delegates to the following piece. Thanks in advance.Thanks for your effort. #region Chain of Responsibility Pattern namespace Chain { public class Player { public string Name { get; set; } public int Score { get; set; } } public abstract class PlayerHandler { protected PlayerHandler _Successor = null; public abstract void HandlePlayer(Player _player); public void SetupHandler(PlayerHandler _handler) { _Successor = _handler; } } public class Employee : PlayerHandler { public override void HandlePlayer(Player _player) { if (_player.Score <= 100) { MessageBox.Show(string.Format("{0} is greeted by Employee", _player.Name)); } else { _Successor.HandlePlayer(_player); } } } public class Supervisor : PlayerHandler { public override void HandlePlayer(Player _player) { if (_player.Score >100 && _player.Score<=200) { MessageBox.Show(string.Format("{0} is greeted by Supervisor", _player.Name)); } else { _Successor.HandlePlayer(_player); } } } public class Manager : PlayerHandler { public override void HandlePlayer(Player _player) { if (_player.Score > 200) { MessageBox.Show(string.Format("{0} is greeted by Manager", _player.Name)); } else { MessageBox.Show(string.Format("{0} got low score", _player.Name)); } } } } #endregion #region Main() void Main() { Chain.Player p1 = new Chain.Player(); p1.Name = "Jon"; p1.Score = 100; Chain.Player p2 = new Chain.Player(); p2.Name = "William"; p2.Score = 170; Chain.Player p3 = new Chain.Player(); p3.Name = "Robert"; p3.Score = 300; Chain.Employee emp = new Chain.Employee(); Chain.Manager mgr = new Chain.Manager(); Chain.Supervisor sup = new Chain.Supervisor(); emp.SetupHandler(sup); sup.SetupHandler(mgr); emp.HandlePlayer(p1); emp.HandlePlayer(p2); emp.HandlePlayer(p3); } #endregion

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  • How to decide which colors to use that look most similar across most screens/monitors?

    - by Lyon
    Hi, I'm baffled. I'm trying to find suitable colors for a logo that would look similar across most monitors/screens. I know it's near impossible, but how does one end up with the color palette that new Google logo and Facebook "blue" uses for example? I've a monitor that has been calibrated, and a few laptop screens that have default settings. Yet both the Google logo and facebook's look similar (although they aren't using colors restricted to the web safe 216 palette. Any ideas? thoughts? Thanks

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  • What's an easy way to set up object communication in Obj-C?

    - by seaworthy
    I am trying to send a slider value from a controller object to a method of a model object. The later is implemented in the separate file and I have appropriate headers. I think the problem is that I am not sure how to instantiate the receiver in order to produce a working method for the controller. Here is the controller's method. -(IBAction)setValue:(id)slider {[Model setValue:[slider floatValue]];} @implementation Model -(void)setValue:(float)n{ printf("%f",n); } @end What I get is 'Model' may not respond to '+setValue' warning and no output in my console. Any insight is appreciated.

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  • Meaning of Primary Key to Microsoft SQL Server 2008

    - by usr
    What meaning does the concept of a primary key have to the database engine of SQL Server? I don't mean the clustered/nonclustered index created on the "ID" column, i mean the constraint object "primary key". Does it matter if it exists or not? Alternatives: alter table add primary key clustered alter table create clustered index Does it make a difference?

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  • PHP: Best solution for links breaking in a mod_rewrite app

    - by psil
    I'm using mod rewrite to redirect all requests targeting non-existent files/directories to index.php?url=* This is surely the most common thing you do with mod_rewrite yet I have a problem: Naturally, if the page url is "mydomain.com/blog/view/1", the browser will look for images, stylesheets and relative links in the "virtual" directory "mydomain.com/blog/view/". Problem 1: Is using the base tag the best solution? I see that none of the PHP frameworks out there use the base tag, though. I'm currently having a regex replace all the relative links to point to the right path before output. Is that "okay"? Problem 2: It is possible that the server doesn't support mod_rewrite. However, all public files like images, stylesheets and the requests collector index.php are located in the directory /myapp/public. Normally mod_rewrite points all request to /public so it seems as if public was actually the root directory too all users. However if there is no mod_rewrite, I then have to point the users to /public from the root directory with a header() call. That means, however that all links are broken again because suddenly all images, etc. have to be called via /public/myimage.jpg Additional info: When there is no mod_rewrite the above request would look like this: mydomain.com/public/index.php/blog/view/1 What would be the best solutions for both problems?

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  • C#: How to inherit constructors?

    - by Ian Boyd
    Imagine a base class with many constructors and a virtual method public class Foo { ... public Foo() {...} public Foo(int i) {...} ... public virtual void SomethingElse() {...} ... } and now I want to create a descendant class that overrides the virtual method: public class Bar : Foo { public override void SomethingElse() {...} } And another descendant that does some more stuff: public class Bah : Bar { public void DoMoreStuff() {...} } Do I really have to copy all constructors from Foo into Bar and Bah? And then if I change a constructor signature in Foo, do I have to update it in Bar and Bah? Is there no way to inherit constructors? Is there no way to encourage code reuse?

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  • where does the professional sheen of a GUI application realistically come from?

    - by JW
    I have been playing around with php-gtk recently and in the past I have experimented with Java to make GUI 'hello world' apps. However both these types of applications have had a bit of a clunky (almost childish) look and feel to them. I cannot deny that they are handy for making apps for in-house use (and I totally respect the amount of community effort that goes into these projects). But I would not necessarily be proud to sell it as a commercial application with a price tag of, say, £450 or £1,000. If I wanted to make an application that had the look and feel of, say, Firefox for Windows, or Adobe xyz, what GUI/language should I use? Is the 'professional sheen' or smart look and feel down to the designer or is it the case that, no matter how good a designer is, picking the right GUI framework is essential to get that look?

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  • How to track history of db tables that include many-to-many mapping tables?

    - by chacmool
    I have seen several questions here on tracking db history, but can't seem to find one that matches our situation. We need to track the history of several tables, some of which are many-to-many linking tables. Eg say we have this schema: EntityA id name EntityB id name ABLink A_id B_id So, tracking changes to EntityA or EntityB seems pretty straightforward. We can keep a log table with the same columns plus a date stamp and user. But what about the links? How do we maintain the set of links that are valid for a given version of the data? We need to be able to recreate a history of the data showing changes in chronological order. So if a link added or deleted, we indicate that. Etc.

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  • coding in native language

    - by radi
    is it possible to someone to invent a new programming language in his native language , and if it possible how to do that and what the tools he need to write compiler for it . thanks .

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  • Storing n-grams in database in < n number of tables.

    - by kurige
    If I was writing a piece of software that attempted to predict what word a user was going to type next using the two previous words the user had typed, I would create two tables. Like so: == 1-gram table == Token | NextWord | Frequency ------+----------+----------- "I" | "like" | 15 "I" | "hate" | 20 == 2-gram table == Token | NextWord | Frequency ---------+------------+----------- "I like" | "apples" | 8 "I like" | "tomatoes" | 12 "I hate" | "tomatoes" | 20 "I hate" | "apples" | 2 Following this example implimentation the user types "I" and the software, using the above database, predicts that the next word the user is going to type is "hate". If the user does type "hate" then the software will then predict that the next word the user is going to type is "tomatoes". However, this implimentation would require a table for each additional n-gram that I choose to take into account. If I decided that I wanted to take the 5 or 6 preceding words into account when predicting the next word, then I would need 5-6 tables, and an exponentially increase in space per n-gram. What would be the best way to represent this in only one or two tables, that has no upper-limit on the number of n-grams I can support?

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  • OOP - Handling Automated Instances of a Class - PHP

    - by dscher
    This is a topic that, as a beginner to PHP and programming, sort of perplexes me. I'm building a stockmarket website and want users to add their own stocks. I can clearly see the benefit of having each stock be a class instance with all the methods of a class. What I am stumped on is the best way to give that instance a name when I instantiate it. If I have: class Stock() { ....doing stuff..... } what is the best way to give my instances of it a name. Obviously I can write: $newStock = new Stock(); $newStock.getPrice(); or whatever, but if a user adds a stock via the app, where can the name of that instance come from? I guess that there is little harm in always creating a new child with $newStock = new Stock() and then storing that to the DB which leads me to my next question! What would be the best way to retrieve 20 user stocks(for example) into instances of class Stock()? Do I need to instantiate 20 new instances of class Stock() every time the user logs in or is there something I'm missing? I hope someone answers this and more important hope a bunch of people answer this and it somehow helps someone else who is having a hard time wrapping their head around what probably leads to a really elegant solution. Thanks guys!

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  • Languages and VMs: Features that are hard to optimize and why

    - by mrjoltcola
    I'm doing a survey of features in preparation for a research project. Name a mainstream language or language feature that is hard to optimize, and why the feature is or isn't worth the price paid, or instead, just debunk my theories below with anecdotal evidence. Before anyone flags this as subjective, I am asking for specific examples of languages or features, and ideas for optimization of these features, or important features that I haven't considered. Also, any references to implementations that prove my theories right or wrong. Top on my list of hard to optimize features and my theories (some of my theories are untested and are based on thought experiments): 1) Runtime method overloading (aka multi-method dispatch or signature based dispatch). Is it hard to optimize when combined with features that allow runtime recompilation or method addition. Or is it just hard, anyway? Call site caching is a common optimization for many runtime systems, but multi-methods add additional complexity as well as making it less practical to inline methods. 2) Type morphing / variants (aka value based typing as opposed to variable based) Traditional optimizations simply cannot be applied when you don't know if the type of someting can change in a basic block. Combined with multi-methods, inlining must be done carefully if at all, and probably only for a given threshold of size of the callee. ie. it is easy to consider inlining simple property fetches (getters / setters) but inlining complex methods may result in code bloat. The other issue is I cannot just assign a variant to a register and JIT it to the native instructions because I have to carry around the type info, or every variable needs 2 registers instead of 1. On IA-32 this is inconvenient, even if improved with x64's extra registers. This is probably my favorite feature of dynamic languages, as it simplifies so many things from the programmer's perspective. 3) First class continuations - There are multiple ways to implement them, and I have done so in both of the most common approaches, one being stack copying and the other as implementing the runtime to use continuation passing style, cactus stacks, copy-on-write stack frames, and garbage collection. First class continuations have resource management issues, ie. we must save everything, in case the continuation is resumed, and I'm not aware if any languages support leaving a continuation with "intent" (ie. "I am not coming back here, so you may discard this copy of the world"). Having programmed in the threading model and the contination model, I know both can accomplish the same thing, but continuations' elegance imposes considerable complexity on the runtime and also may affect cache efficienty (locality of stack changes more with use of continuations and co-routines). The other issue is they just don't map to hardware. Optimizing continuations is optimizing for the less-common case, and as we know, the common case should be fast, and the less-common cases should be correct. 4) Pointer arithmetic and ability to mask pointers (storing in integers, etc.) Had to throw this in, but I could actually live without this quite easily. My feelings are that many of the high-level features, particularly in dynamic languages just don't map to hardware. Microprocessor implementations have billions of dollars of research behind the optimizations on the chip, yet the choice of language feature(s) may marginalize many of these features (features like caching, aliasing top of stack to register, instruction parallelism, return address buffers, loop buffers and branch prediction). Macro-applications of micro-features don't necessarily pan out like some developers like to think, and implementing many languages in a VM ends up mapping native ops into function calls (ie. the more dynamic a language is the more we must lookup/cache at runtime, nothing can be assumed, so our instruction mix is made up of a higher percentage of non-local branching than traditional, statically compiled code) and the only thing we can really JIT well is expression evaluation of non-dynamic types and operations on constant or immediate types. It is my gut feeling that bytecode virtual machines and JIT cores are perhaps not always justified for certain languages because of this. I welcome your answers.

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  • Rails Full Engine using a Full Engine

    - by SirLenz0rlot
    I've got this full rails engine Foo with functionality X. I want to make another engine, engine Bar, that is pretty much the same, but override funcitonality x with y. (it basically does the same, but a few controller actions and views are differently implemented). (I might split this later in several mountable engines, but for now, this will be the setup: project Baz, using engine Bar, which uses engine Foo) I would like to know if there are any pitfalls. It doesn't seem like a pattern that is often used? Anybody else using this 'some sort of engine inheritance'?

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  • Using inheritance and polymorphism to solve a common game problem

    - by Barry Brown
    I have two classes; let's call them Ogre and Wizard. (All fields are public to make the example easier to type in.) public class Ogre { int weight; int height; int axeLength; } public class Wizard { int age; int IQ; int height; } In each class I can create a method called, say, battle() that will determine who will win if an Ogre meets and Ogre or a Wizard meets a Wizard. Here's an example. If an Ogre meets an Ogre, the heavier one wins. But if the weight is the same, the one with the longer axe wins. public Ogre battle(Ogre o) { if (this.height > o.height) return this; else if (this.height < o.height) return o; else if (this.axeLength > o.axeLength) return this; else if (this.axeLength < o.axeLength) return o; else return this; // default case } We can make a similar method for Wizards. But what if a Wizard meets an Ogre? We could of course make a method for that, comparing, say, just the heights. public Wizard battle(Ogre o) { if (this.height > o.height) return this; else if (this.height < o.height) return o; else return this; } And we'd make a similar one for Ogres that meet Wizard. But things get out of hand if we have to add more character types to the program. This is where I get stuck. One obvious solution is to create a Character class with the common traits. Ogre and Wizard inherit from the Character and extend it to include the other traits that define each one. public class Character { int height; public Character battle(Character c) { if (this.height > c.height) return this; else if (this.height < c.height) return c; else return this; } } Is there a better way to organize the classes? I've looked at the strategy pattern and the mediator pattern, but I'm not sure how either of them (if any) could help here. My goal is to reach some kind of common battle method, so that if an Ogre meets an Ogre it uses the Ogre-vs-Ogre battle, but if an Ogre meets a Wizard, it uses a more generic one. Further, what if the characters that meet share no common traits? How can we decide who wins a battle?

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  • Interface vs Abstract Class (general OO)

    - by Kave
    Hi, I have had recently two telephone interviews where I've been asked about the differences between an Interface and an Abstract class. I have explained every aspect of them I could think of, but it seems they are waiting for me to mention something specific, and I dont know what it is. From my experience I think the following is true, if i am missing a major point please let me know: Interface: Every single Method declared in an Interface will have to be implemented in the subclass. Only Events, Delegates, Properties (C#) and Methods can exist in a Interface. A class can implement multiple Interfaces. Abstract Class Only Abstract methods have to be implemented by the subclass. An Abstract class can have normal methods with implementations. Abstract class can also have class variables beside Events, Delegates, Properties and Methods. A class can only implement one abstract class only due non-existence of Multi-inheritance in C#. 1) After all that the interviewer came up with the question What if you had an Abstract class with only abstract methods, how would that be different from an interface? I didnt know the answer but I think its the inheritance as mentioned above right? 2) An another interviewer asked me what if you had a Public variable inside the interface, how would that be different than in Abstract Class? I insisted you can't have a public variable inside an interface. I didn't know what he wanted to hear but he wasn't satisfied either. Many Thanks for clarification, Kave See Also: When to use an interface instead of an abstract class and vice versa Interfaces vs. Abstract Classes How do you decide between using an Abstract Class and an Interface?

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  • Oracle - Is there any effects of not having a primary key on a table ?

    - by Sathya
    We use sequence numbers for primary keys on the tables. There are some tables where we dont really use the primary key for any querying purpose. But, we have Indexes on other columns. These are non-unique indexes. The queries use these non-primary key columns in the WHERE conditions. So, I dont really see any benefit of having a primary key on such tables. My experience with SQL 2000 was that, it used to replicate tables which had some primary key. Otherwise it would not. I am using Oracle 10gR2. I would like to know if there are any such side-effects of having tables that dont have primary key.

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  • Is there a way to restrict access to a public method to only a specific class in C#?

    - by Anon
    I have a class A with a public method in C#. I want to allow access to this method to only class B. Is this possible? UPDATE: This is what i'd like to do: public class Category { public int NumberOfInactiveProducts {get;} public IList<Product> Products {get;set;} public void ProcessInactiveProduct() { // do things... NumberOfInactiveProducts++; } } public class Product { public bool Inactive {get;} public Category Category {get;set;} public void SetInactive() { this.Inactive= true; Category.ProcessInactiveProduct(); } } I'd like other programmers to do: var prod = Repository.Get<Product>(id); prod.SetInactive(); I'd like to make sure they don't call ProcessInactiveProduct manually: var prod = Repository.Get<Product>(id); prod.SetInactive(); prod.Category.ProcessInactiveProduct(); I want to allow access of Category.ProcessInactiveProduct to only class Product. Other classes shouldn't be able to call Category.ProcessInactiveProduct.

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