Search Results

Search found 6569 results on 263 pages for 'specification pattern'.

Page 202/263 | < Previous Page | 198 199 200 201 202 203 204 205 206 207 208 209  | Next Page >

  • Interface with inner implementation - good or bad

    - by dermoritz
    I am working on a project with many someInterface - someInterfaceImpl-pairs. Some days ago I got the idea (probably inspired by reading some objective c code) to include the default implementations as an inner class. Now some colleagues (all with much more java experience than me) saw this idea - feedback was between shocked and surprised ("this is working?"). I googled around a bit but didn't find much evidence of usefulness of this "pattern" (personal i like it): pdf-paper and a faq about code style What do you think - especially in those cases where an "default" implementation is tightly coupled to an interface. Update i just found this: Java Interface-Implementation Pair (see accepted answer)

    Read the article

  • Regular Expression; Find whether a line contains any word with more than X characters.

    - by Simpsoid
    Hi, I am trying to use a Validator on a ASP.NET site and need to find whether the Street Address textbox contains a valid entry. Entries with words that are longer than X characters (in this case 25, with no punctuation or spaces) will cause the HTML on a printed A4 page to not wrap properly and therefore not to confrom to certain sizes correctly pushing the margins off. For a street address I want to match that something like "201 Long Road" is valid but "235 ReallyLongAndNarrowWindingRoadBesideTheRiver Street" is invalid. Using a Microsoft .Net Regular Expression Validator I need to know what the RegEx pattern might be. I think if it does find a match the Validator will fire correctly however if there is no match the Validator won't fire and the Update button (in this case) won't fire. Since Street addresses can contain Capital Letters and numbers etc. it will need to accomodate for that and also Spaces, Commas, Semi-Colons and Colons and Hyphens are valid characters too. Any help would be greatly appreciated as I am really stuck with this problem. Thanks, David

    Read the article

  • Teacher confused about MVC?

    - by Gideon
    I have an assignment to create a game in java using MVC as a pattern. The thing is that stuff I read about MVC aren't really what the teacher is telling me. What I read is that the Model are the information objects, they are manipulated by the controllers. So in a game the controller mutates the placement of the objects and check if there is any collision etc. What my teacher told me is that I should put everything that is universal to the platform in the models and the controllers should only tell the model which input is given. That means the game loop will be in a model class, but also collision checks etc. So what I get from his story is that the View is the screen, the Controller is the unput handeler, and the Model is the rest. Can someone point me in the right direction?

    Read the article

  • Rails: Best practice to store user settings?

    - by ole_berlin
    Hi, I'm wondering what the best way is to store user settings? For a web 2.0 app I want users to be able to select certain settings. At the moment is it only when to receive email notifications. The easiest way would be to just create a Model "Settings" and have a column for every setting and then have a 1-1 relationship with users. But is there a pattern to solve this better? Is it maybe better to store the info in the user table itself? Or should I use a table with "settings_name" and "settings_value" to be completely open about the type of settings stored there (without having to run any migrations when adding options)? What is your opinion? Thanks

    Read the article

  • Castle Windsor Weak Typed Factory

    - by JeffN825
    In a very very limited number of scenarios, I need to go from an unknown Type (at compile time) to an instance of the object registered for that type. For the most part, I use typed factories and I know the type I want to resolve at compile time...so I inject a Func<IMyType> into a constructor ...but in these limited number of scenarios, in order to avoid a direct call to the container (and thus having to reference Windsor from the library, which is an anti-pattern I'd like to avoid), I need to inject a Func<Type,object>...which I want to internally container.Resolve(type) for the Type parameter of the Func. Does anyone have some suggestions on the easiest/most straightforward way of setting this up? I tried the following, but with this setup, I end up bypassing the regular TypedFactoryFacility altogether which is definitely not what I want: Kernel.Register(Component.For(typeof (Func<Type, object>)).LifeStyle.Singleton.UsingFactoryMethod( (kernel, componentModel, creationContext) => kernel.Resolve(/* not sure what to put here... */))); Thanks in advance for any assistance.

    Read the article

  • How to map inheritance with property returned other inheritance?

    - by dario-g
    Hi I have abstract class Vehicle and two classes that derive from: Car and ForkLift. public abstract class Vehicle { public EngineBase Engine { get; set; } } public class Car : Vehicle { public GasEngine Engine { get; set; } } public class ForkLift : Vehicle { public ElectricEngine Engine { get; set; } } and Engine clasess: public abstract class Engine { } public class GasEngine : Engine { } public class ElectricEngine : Engine { } Engines are mapped with "table per class hierarchy". With Vehicles I want to use the same pattern. How to map Engine class and derived with that Engine property?

    Read the article

  • Using Regular Expressions

    - by bebeTech
    I am having problems trying to use the regular expression that I used in JavaScript. On a web page, you may have: <b>Renewal Date:</b> 03 May 2010</td> I just want to be able to pull out the 03 May 2010, remembering that a webpage has more than just the above content. The way I currently perform this using JavaScript is: DateStr = /<b>Renewal Date:<\/b>(.+?)<\/td>/.exec(returnedHTMLPage); I tried to follow some tutorials on java.util.regex.Pattern and java.util.regex.Matcher with no luck. I can't seem to be able to translate (.+?) into something they can understand?? thanks, Noeneel

    Read the article

  • Using MySQL as a job queue

    - by user237815
    I'd like to use MySQL as a job queue. Multiple machines will be producing and consuming jobs. Jobs need to be scheduled; some may run every hour, some every day, etc. It seems fairly straightforward: for each job, have a "nextFireTime" column, and have worker machines search for the job with the nextFireTime, change the status of the record to "inProcess", and then update the nextFireTime when the job ends. The problem comes in when a worker dies silently. It won't be able to update the nextFireTime or set the status back to "idle". Unfortunately, jobs can be long-running, so a reaper thread that looks for jobs that have been inProcess too long isn't an option. There's no timeout value that would work. Can anyone suggest a design pattern that would properly handle unreliable worker machines?

    Read the article

  • Where to start with map application

    - by rfders
    Hi there, i'm trying to desing a new application which allow user see he/her current location on a custom map (office, university compus, etc). but actually i have a couple of question in my mind (i haven't designed this kind of application before). i'm wondering: How can i draw my own maps, what is the best option for it? there any format that i have to care of, there are any specification about it ? Once i have my custom map. how can i do to mapping a global position system with the local positions ? What are the tricks behing zoom on maps ? just differents layers with more or less informations and those layers changes on users demand ? If a whant to mark some specific points over the map, like a cafeteria, boss's office etc, how can i do that ? Sorry if my questions are too much generics and dumb, but i really need some clues about this topic because i don't have any idea how to design this kind of application as best as possible. and we don't whant to reinvent the wheel. I will appreciate any help that you can provide me in order to desing this application

    Read the article

  • Javascript object encapsulation that tracks changes

    - by Raynos
    Is it possible to create an object container where changes can be tracked Said object is a complex nested object of data. (compliant with JSON). The wrapper allows you to get the object, and save changes, without specifically stating what the changes are Does there exist a design pattern for this kind of encapsulation Deep cloning is not an option since I'm trying to write a wrapper like this to avoid doing just that. The solution of serialization should only be considered if there are no other solutions. An example of use would be var foo = state.get(); // change state state.update(); // or state.save(); client.tell(state.recentChange()); A jsfiddle snippet might help : http://jsfiddle.net/Raynos/kzKEp/ It seems like implementing an internal hash to keep track of changes is the best option. [Edit] To clarify this is actaully done on node.js on the server. The only thing that changes is that the solution can be specific to the V8 implementation.

    Read the article

  • Prevent Erroneous Property Assignment

    - by Gordon
    Porting android applications to iphone applications always gives me the following pattern that I accidentally create: - (void) myFunc:(id)prop { self.property = property; } Which instead should be: - (void) myFunc:(id)prop { self.property = prop; } This always causes my program to quietly break because property gets reset to its existing value rather than being set to the new value, 'prop'. I cannot name the parameter 'prop' to 'property' since the compile complains that the parameter masks the instance variables visibility. Is there a good way to avoid this situation? There are no compiler warnings. Is there a way to make xcode prevent this? I cannot see very many situations where you would set a property to the value of its underlying instance variable (maybe to trigger a KVO binding?), but I don't see myself doing that in majority of cases. I understand the above code is synthetic and should be done with @synthesize, but I am just using it as a simplified example to illustrate my point.

    Read the article

  • How to encrypt a RSAKey using another RSAKey?

    - by Tom Brito
    I know its not the usual thing to do. But the specification I'm implementing is discribed this way, and I cannot run out. I was trying to encrypt the modulus and exponent of the private key, but the following test code raises an exception because the byte array is 1 byte larger then the maximum allowed by RSA block: import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.NoSuchAlgorithmException; import java.security.NoSuchProviderException; import java.security.interfaces.RSAPrivateKey; import java.security.interfaces.RSAPublicKey; import javax.crypto.Cipher; import org.apache.commons.lang.ArrayUtils; public class TEST { public static KeyPair generateKeyPair() throws NoSuchAlgorithmException, NoSuchProviderException { KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA", "BC"); keyPairGenerator.initialize(1024); return keyPairGenerator.generateKeyPair(); } public static void main(String[] args) throws Exception { KeyPair keyPair = generateKeyPair(); RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); System.out.println("Priv modulus len = " + privateKey.getModulus().bitLength()); System.out.println("Priv exponent len = " + privateKey.getPrivateExponent().bitLength()); System.out.println("Priv modulus toByteArray len = " + privateKey.getModulus().toByteArray().length); byte[] byteArray = privateKey.getModulus().toByteArray(); // the byte at index 0 have no value (in every generation it is always zero) byteArray = ArrayUtils.subarray(byteArray, 1, byteArray.length); System.out.println("byteArray size: " + byteArray.length); RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); Cipher cipher = Cipher.getInstance("RSA", "BC"); cipher.init(Cipher.ENCRYPT_MODE, publicKey); byte[] encryptedBytes = cipher.doFinal(byteArray); System.out.println("Success!"); } } (obs. its just a test, i would never encrypt the private key with its pair public key) The byte array is 128 bytes, the exactly maximum allowed by a RSA block, so why the exception? And how to fix it?

    Read the article

  • Disposing a Bitmap through its Finalizer

    - by devoured elysium
    I have a complex program in which I have to first create, then use wrappers around bitmaps and send them across a lot of different classes. The problem in the end is deciding which classes should dispose the bitmaps. Most of the time the end classes don't know if they can indeed dispose the bitmap as the same bitmap can be used in several places. Also, I can't just copy the bitmaps because this is a kind of resource intensive algorithm and doing it would be dead slow. I looked up on reflector for Image/Bitmap's implementations and they seem to use the Dispose Pattern. So, even if I don't call Dispose(), the CLR will eventually call it some other time. Is it too bad if I just let the bitmaps be as they are, and let the finalizer take care of them?

    Read the article

  • Is it considered bad practice to have ViewModel objects hold the Dispatcher?

    - by stiank81
    My WPF application is structured using the MVVM pattern. The ViewModels will communicate asynchronously with a server, and when the requested data is returned a callback in the ViewModel is triggered, and it will do something with this data. This will run on a thread which is not the UI Thread. Sometimes these callbacks involve work that needs to be done on the UI thread, so I need the Dispatcher. This might be things such as: Adding data to an ObservableCollection Trigger Prism commands that will set something to be displayed in the GUI Creating WPF objects of some kind. I try to avoid the latter, but the two first points here I find to be reasonable things for ViewModels to do. So; is it okay to have ViewModels hold the Dispatcher to be able to Invoke commands for the UI thread? Or is this considered bad practice? And why?

    Read the article

  • Allow a new line anywhere in the regex?

    - by Scott Chamberlain
    I am having a find a replace in a bunch of RTF documents, The basic pattern I need is \{(?:\\\*)?\\field\\fldlock\{\\\*\\fldinst ?MERGEFIELD ?((?:\\.*?)?[\w\[\]]+?)(?:\\.*?)?\}(?:\{\\fldrslt\})?\} However I then found out there could potentialy be a newline before each slash, so it turned in to this. \{(?:\s*\\\*)?\s*\\field\s*\\fldlock\s*\{\s*\\\*\s*\\fldinst\s*MERGEFIELD\s*((?:\\.*?)?[\w\[\]]+?(?:\s*\\.*?)?)?\s*\}(?:\s*\{\s*\\fldrslt\s*\})?\s*\} But then I hit this it fails fees totaling $\protect {\field\fldlock{\*\fldinst MERGEFIELD ENTEROUTSTANDINGVETERINARYF EES}}\plain\f0\fs24\prot Is there way have to have it match a new line anywhere in the search too without adding (?:\r?\n)? everywhere? EDIT To clear up confusion on the new lines. I need to keep the newlines in the document, I only want to remove the newlines if they are inside my match, so in the final example I posted it should replace fees totaling $\protect {\field\fldlock{\*\fldinst MERGEFIELD ENTEROUTSTANDINGVETERINARYF EES}}\plain\f0\fs24\prot with fees totaling $\protect ENTEROUTSTANDINGVETERINARYFEES\plain\f0\fs24\prot

    Read the article

  • Question about regex in linux commands.

    - by smwikipedia
    I ran the following command at linux bash: apt-cache search hex.*(view|edit) My intention was to find any software packages whose name/description contains the pattern 'hex.*(view|edit)'. But among the results I got this: kipi-plugins - image manipulation/handling plugins for KIPI aware programs How could this be in the results list? I didn't see any matching string in this result. Is this a bug of the apt-cache search command? Or do I mis-understand how the regex is used by this command? Many thanks.

    Read the article

  • Java splitting string by custom regex match

    - by slikz
    I am completely new to regular expressions so I'm looking for a bit of help here. I am compiling under JDK 1.5 Take this line as an example that I read from standard input: ab:Some string po:bubblegum What I would like to do is split by the two characters and colon. That is, once the line is split and put into a string array, these should be the terms: ab:Some string po:bubblegum I have this regex right now: String[] split = input.split("[..:]"); This splits at the semicolon; what I would like is for it to match two characters and a semicolon, but split at the space before that starts. Is this even possible? Here is the output from the string array: ab Some String po bubblegum I've read about Pattern.compile() as well. Is this something I should be considering?

    Read the article

  • Are there any XML Editors with FTP and file-tree browsing combined?

    - by JW
    Are there any (free preferably) XML Editors combined with FTP and file-tree browsing Project wide find+Replace I.e A bit like what Dreamweaver MX is but with fancier XML capabilities /XSLT /XSD Perhaps even DW does this...im still on an older version. I'd like to keep a smooth flow between find-edit-view-upload any ideas? Background: I have converted most of the html files of my legacy site into XML (which match the directory structure of my 'public docs' folder). Part of a step towards turning it into completely dynamic data via MVC /Front Controller Pattern.

    Read the article

  • Is there anything wrong with a class with all static methods?

    - by MatthewMartin
    I'm doing code review and came across a class that uses all static methods. The entrance method takes several arguments and then starts calling the other static methods passing along all or some of the arguments the entrance method received. It isn't like a Math class with largely unrelated utility functions. In my own normal programming, I rarely write methods where Resharper pops and says "this could be a static method", when I do, they tend to be mindless utility methods. Is there anything wrong with this pattern? Is this just a matter of personal choice if the state of a class is held in fields and properties or passed around amongst static methods using arguments?

    Read the article

  • Scala's tuple unwrapping nuance

    - by Paul Milovanov
    I've noticed the following behavior in scala when trying to unwrap tuples into vals: scala> val (A, B, C) = (1, 2, 3) <console>:5: error: not found: value A val (A, B, C) = (1, 2, 3) ^ <console>:5: error: not found: value B val (A, B, C) = (1, 2, 3) ^ <console>:5: error: not found: value C val (A, B, C) = (1, 2, 3) ^ scala> val (u, v, w) = (1, 2, 3) u: Int = 1 v: Int = 2 w: Int = 3 Is that because scala's pattern matching mechanism automatically presumes that all identifiers starting with capitals within patterns are constants, or is that due to some other reason? Thanks!

    Read the article

  • Caching result of SELECT statement for reuse in multiple queries

    - by Andrew
    I have a reasonably complex query to extract the Id field of the results I am interested in based on parameters entered by the user. After extracting the relevant Ids I am using the resulting set of Ids several times, in separate queries, to extract the actual output record sets I want (by joining to other tables, using aggregate functions, etc). I would like to avoid running the initial query separately for every set of results I want to return. I imagine my situation is a common pattern so I am interested in what the best approach is. The database is in MS SQL Server and I am using .NET 3.5.

    Read the article

  • are Hierarchical SIngletons in Java possible?

    - by Zach H
    I've been toying with an interesting idea (No idea if I'll include it in any code, but it's fun to think about) Let's say we have a program that requires a large number of classes, all of a certain subclass. And those classes all need to be singletons. Now, we could write the singleton pattern for each of those classes, but it seems wasteful to write the same code over and over, and we already have a common base class. It would be really nice to create a getSingleton method of A that when called from a subclass, returns a singleton of the B class (cast to class A for simplicity) class A{ public A getSingleton(){ //Wizardry } } class B extends A{ } A blargh = B.getSingleton() A gish = B.getSingleton() if(A == B) System.out.println("It works!") It seems to me that the way to do this would be to recognize and call B's default constructor (assuming we don't need to pass anything in.) I know a little of the black magic of reflection in Java, but i'm not sure if this can be done. Anyone interested in puzzling over this?

    Read the article

  • Zend_Form: Is this really the way we should be doing things?

    - by Francis Daigle
    OK. I understand how to use Zend_Form and it's implementation of the decorator pattern. My question is, is this the best way to be going about creating forms? Shouldn't a documents forms be left to to the front-end rather than generating forms programmatically? Doesn't this kinda violate the whole idea of keeping things separate? I mean, really, even providing that you have a good understanding of the methodology being employed, does it really save one that much time? I guess what I'm looking for is some guidance as to what might be considered 'best practice'. I'm not saying that Zend_Form doesn't have it's place, I'm just wondering if it should be used in all cases (or not). And this has nothing to do with validation. I'm just thinking that something more akin to using the 'ViewScript' approach might be more appropriate in most cases. Your thoughts?

    Read the article

  • A window that behaves both modally and non-modally

    - by Chris
    I want to create a WPF window that behaves as a modal dialogue box while at the same time facilitating selected operations on certain other windows of the same application. An example of this behaviour can be seen in Adobe Photoshop, which offers several dialogues that allow the user to use an eyedropper tool to make selections from an image while disabling virtually all other application features. I'm guessing that the way forward is to create a non-modal, always-on-top dialogue and programmatically disable those application features that are not applicable to the dialogue. Is there an easy way to achieve this in WPF? Or perhaps there's a design pattern I could adopt.

    Read the article

  • Is there an ORM that allows a "plugin" to extend the database?

    - by IP
    So, I've been searching for the answer to this, but I can't find anything I have an Entity Framework Model (MyModel1) - for now, we'll say this contains a "Users" table It's part of a big app, that has a references to an "Addresses" project The addresses project contains an Entity Framework Model (MyModel2), this contains a Users table, and an Addresses table (pointing to the same database. The main app has a control that edits the user, and in that control it has an "addresses" control which actually exists in the "Addresses" project. To make this work, the User control passes the User object down to the addresses control, however, as the User that's been passed belongs to MyModel1 and not MyModel2, another User object has to be loaded up, then it can be used. This isn't ideal as I've had to load up the User twice. Is there a way of say, MyModel2 extending MyModel1, which effectively just adds a relationship to "User". Or is there an ORM that would handle this better? Or even a design pattern that would handle this better?

    Read the article

< Previous Page | 198 199 200 201 202 203 204 205 206 207 208 209  | Next Page >