Search Results

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

Page 203/263 | < Previous Page | 199 200 201 202 203 204 205 206 207 208 209 210  | Next Page >

• 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

• Generic object load function for scala

  - by Isaac Oates

  I'm starting on a Scala application which uses Hibernate (JPA) on the back end. In order to load an object, I use this line of code: val addr = s.load(classOf[Address], addr_id).asInstanceOf[Address]; Needless to say, that's a little painful. I wrote a helper class which looks like this: import org.hibernate.Session class DataLoader(s: Session) { def loadAddress(id: Long): Address = { return s.load(classOf[Address], id).asInstanceOf[Address]; } ... } So, now I can do this: val dl = new DataLoader(s) val addr = dl loadAddress(addr_id) Here's the question: How do I write a generic parametrized method which can load any object using this same pattern? i.e val addr = dl load[Address](addr_id) (or something along those lines.) I'm new to Scala so please forgive anything here that's especially hideous.

  Read the article

• Customer provider Password Reset client.

  - by ProfK

  I'm looking for guidence on writing a custom password reset UI, but it must fit the Provider 'Pattern', or degrade silently to built-in defaults. E.g. my Reset Control must collect extra information, and perform differently to the standard Password Recovery Control. It must close as possible use the standard MembershipProvider interface for standard functions, and only use an extended interface for the non-standard stuff. I'd like some reading on issues such as, what must I ask the Membership Provider for, and what must I do myself. What must I tell the provider (service?) about what I do? Etc.

  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

• 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

• Class design question (Disposable and singleton behavior)

  - by user137348

  The Repository class has singleton behavior and the _db implements the disposable pattern. As excepted the _db object gets disposed after the first call and because of the singleton behavior any other call of _db will crash. [ServiceBehavior(InstanceContextMode=InstanceContextMode.Single)] public class Repository : IRepository { private readonly DataBase _db; public Repository(DataBase db) { _db = db; } public int GetCount() { using(_db) { return _db.Menus.Count(); } } public Item GetItem(int id) { using(_db) { return _db.Menus.FirstOrDefault(x=>x.Id == id); } } } My question is, is there any way to design this class to work properly without removing the singleton behavior? The Repositoryclass will be serving big amount of requests.

  Read the article

• Static assembly initialization

  - by ph0enix

  I'm attempting to develop an Interceptor framework (in C#) where I can simply implement some interfaces, and through the use of some static initialization, register all my Interceptors with a common Dispatcher to be invoked at a later time. The problem lies in the fact that my Interceptor implementations are never actually referenced by my application so the static constructors never get called, and as a result, the Interceptors are never registered. If possible, I would like to keep all references to my Interceptor libraries out of my application, as this is my way of (hopefully) enforcing loose coupling across different modules. Hopefully this makes some sense. Let me know if there's anything I can clarify... Does anyone have any ideas, or perhaps a better way to go about implementing my Interceptor pattern? TIA, Jeremy

  Read the article

• DTOs Collections mapping Problem

  - by the_knight5000

  I'm working now on a multi-tier project which has layers as following : DAL BLL GUI Layer and Shared DTOs between BLL and GUI layers. I'm facing a problem in mapping the Objects from DAO To DTO, No problem in the simple objects. The problem is in the Objects who have child collections of another objects. ex: Author Category --Categories --Authors the execution goes in an infinite loop of mapping and it get more complex when I want model Self-join tables ex: Safe Safe --TransferSafe(Collection<Safe>) --TransferSafe(Collection<Safe>) the execution goes in an infinite loop of mapping any suggestions about a good solution or a practical mapping pattern?

  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

• MVC: Structuring Feed Output

  - by Brian Wigginton

  The framework I'm using on my project follows the MVC Pattern. I"M building JSON feeds and need to structure them in a different way then what the system gives me by default from the ORM. Where should I be handling the task of mangling and shaping my data that I'll serve up, in the model, view or controller? Right now I'm doing it in my controller, then passing that data to the view. I can see this fitting better under the Model or the View but not sure which one.

  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

• Error " Index exceeds Matrix dimensions"

  - by Mola

  Hi experts, I am trying to read an excel 2003 file which consist of 62 columns and 2000 rows and then draw 2d dendrogram from 2000 pattern of 2 categories of a data as my plot in matlab. When i run the script, it gives me the above error. I don't know why. Anybody has any idea why i have the above error? My data is here: http://rapidshare.com/files/383549074/data.xls Please delete the 2001 column if you want to use the data for testing. and my code is here: % Script file: cluster_2d_data.m d=2000; n1=22; n2=40; N=62 Data=xlsread('data.xls','A1:BJ2000'); X=Data'; R=1:2000; C=1:2; clustergram(X,'Pdist','euclidean','Linkage','complete','Dimension',2,... 'ROWLABELS',R,'COLUMNLABELS',C,'Dendrogram',{'color',5})

  Read the article

• With vim, how can I use autocmd's for files in subdirectories of a specific path?

  - by René Nyffenegger

  I am trying to figure out how I can define an autocmd that influences all files under a specific path. The autocmd I have tried is something like autocmd BufNewFile,BufRead /specificPath/** imap <buffer> .... Now, I'd expect this autocmd to be used if I edited, say, /foo/bar/specificPath/baz/something/bla.txt, but not if I edited /foo/bar/here/and/there/moreBla.txt If I start vim being in a directory 'above' specificPath, this works as I want it. But it doesn't if I am below that directory. Obviously, the autocmd's pattern is matched against the relative file name, not the absolute one.

  Read the article

• Why is there "data" and "newtype" in Haskell?

  - by martingw

  To me it seems that a newtype definition is just a data definition that obeys some restrictions (only one constructor and such), and that due to these restrictions the runtime system can handle newtypes more efficiently. Ok, and the handling of pattern matching for undefined values is slightly different. But suppose Haskell would only knew data definitions, no newtypes: Couldn't the compiler find out for himself whether a given data definition obeys these restrictions, and automatically treat it more efficiently? I'm sure I'm missing out on something, these Haskell designers are so clever, there must be some deeper reason for this...

  Read the article

• Sequencing ajax requests

  - by Scott Evernden

  I find I sometimes need to iterate some collection and make an ajax call for each element. I want each call to return before moving to the next element so that I don't blast the server with requests - which often leads to other issues. And I don't want to set async to false and freeze the browser. Usually this involves setting up some kind of iterator context that i step thru upon each success callback. I think there must be a cleaner simpler way? Does anyone have a clever design pattern for how to neatly work thru a collection making ajax calls for each item?

  Read the article

• Disable globbing in PHP exec()

  - by wxs

  I have a PHP script which calls another script in order to add IP addresses to a whitelist. I sometimes want to whitelist all addresses, in which case I have it call exec("otherscript *.*.*.*", output, retval); This worked fine, adding the string "*.*.*.*" to the whitelist until I happened to have another file in the directory of the php script that matched that pattern ("foo.1.tar.gz"), at which point the wildcards were expanded, and I ended up with the filename in my whitelist. Is there some way to disable globbing in php's exec? It isn't mentioned in the PHP docs as far as I can tell.

  Read the article

• What are good examples of perfectly acceptable approaches to development that are NOT test driven development (TDD)?

  - by markbruns

  The TDD cycle is test, code, refactor, (repeat) and then ship. TDD implies development that is driven by testing, specifically that means understanding requirements and then writing tests first before developing or writing code. My natural inclination is a philosophical bias in favor of TDD; I would like to be convinced that there are other approaches that now work well or even better than TDD so I have asked this question. What are examples of perfectly acceptable approaches that NOT test driven development? I can think of plenty approaches that are not TDD but could be a lot more trouble than what they are worth ... it's not moral judgement, it's just that they are cost more than they are worth ... the following are simply examples of things that might be ok as learning exercises, but approaches I'd find to be NOT acceptable in serious production and NOT TDD might include: Inspecting quality into your product -- Focusing efforts on developing a proficiency in testing/QA can be problematic, especially if you don't work on the requirements and development side first ... symptom of this include bug triaging where the developers have so many different bugs to deal with it, it is necessary to employ a form of triage -- each development cycle gets worse and worse, programmers work more and more hours, sleep less and less, struggle to keep going in death march until they are consumed. Superstition ... believing in things that you don't understand -- this would involve borrowing code that you believe has been proven or tested from somewhere, e.g. legacy code, a magic code starter wizard or an open source project, and you go forward hacking up a storm of modifications, sliding FaceBook Connect into your the user interface, inventing some new magic features on the fly (e.g. a mashup using the Twitter API, GoogleMaps API and maybe Zappos API), showing off your cool new "product" to a few people and then writing up a simple "specification" and list of "test cases" and turning that over to Mechanical Turk for testing.

  Read the article

• titleForHeaderInSection is not updating Section Header information correctly

  - by Jim

  I have two tableviews where one navigates to the next. Both use more or less the same code and use the managedObjectContext and FetchedResultsController design pattern to provide the relevant data for both tables. My problem happens when I navigate from the first to the second tableview and the data has only one Section Header / Row in the tableview. The data will then not update Section Header information. It does when there is more than one row but not if there is only one row. It leaves the information from the first attempt in place. I can confirm the row data is correct so the relevant data should be being passed to the Section Header correctly but it isn't. Has anyone else come across this problem?

  Read the article

• Should member variables of global objects be made global as well?

  - by David Wong

  I'm developing plugins in Eclipse which mandates the use of singleton pattern for the Plugin class in order to access the runtime plugin. The class holds references to objects such as Configuration and Resources. In Eclipse 3.0 plug-in runtime objects are not globally managed and so are not generically accessible. Rather, each plug-in is free to declare API which exposes the plug-in runtime object (e.g., MyPlugin.getInstance() In order for the other components of my system to access these objects, I have to do the following: MyPlugin.getInstance().getConfig().getValue(MyPlugin.CONFIGKEY_SOMEPARAMETER); , which is overly verbose IMO. Since MyPlugin provides global access, wouldn't it be easier for me to just provide global access to the objects it manages as well? MyConfig.getValue(MyPlugin.CONFIGKEY_SOMEPARAMETER); Any thoughts? (I'm actually asking because I was reading about the whole "Global variable access and singletons are evil" debates)

  Read the article

• How do you extend a Ruby module with macro-like metaprogramming methods?

  - by Ian Terrell

  Consider the following extension (the pattern popularized by several Rails plugins over the years): module Extension def self.included(recipient) recipient.extend ClassMethods recipient.class_eval { include InstanceMethods } end module ClassMethods def macro_method puts "Called macro_method within #{self.name}" end end module InstanceMethods def instance_method puts "Called instance_method within #{self.object_id}" end end end If you wished to expose this to every class, you can do the following: Object.send :include, Extension Now you can define any class and use the macro method: class FooClass macro_method end #=> Called macro_method within FooClass And instances can use the instance methods: FooClass.new.instance_method #=> Called instance_method within 2148182320 But even though Module.is_a?(Object), you cannot use the macro method in a module: module FooModule macro_method end #=> undefined local variable or method `macro_method' for FooModule:Module (NameError) This is true even if you explicitly include the original Extension into Module with Module.send(:include, Extension). How do you add macro like methods to Ruby modules?

  Read the article

• Date or String declaration in a javabean

  - by Jeff

  Should I declare an attribute in a javabean that holds a date value a user types in on an HTML form as a String or Date? I feel I should declare as a Date, however, since I do server validation on all form data, if the date doesn't validate, when I pass the form bean back to the jsp view for correcting, I lose the date value that the user tried to type in. If I declare as a String, if the date doesn't validate, I'm able to set the string value in the bean and pass the bean back to the view and the user can see what they incorrectly typed. But with a String declaration for Date inputs I forsee problems down the road with my DAO. I want to be able to use a DAO utility which generates a prepare statement using setObject. In my html form I request dates to be mm/dd/yyyy and in DAO i'm using Oracle Date. I can not use hibernate or such, since this is a corporate intranet. What is the best practice "pattern" I should be following??

  Read the article

• I'd want a method to be called only by objects of a specific class

  - by mp

  Suppose you have this class: public class A { private int number; public setNumber(int n){ number = n; } } I'd like the method setNumber could be called only by objects of a specific class. Does it make sense? I know it is not possible, is it? Which are the design alternatives? Some well known design pattern? Sorry for the silly question, but I'm a bit rusty in OO design.

  Read the article

• Why are configuration arrays acceptible parameters in PHP and Javascript?

  - by RenderIn

  In most other OO languages it would be sacrilege to have each function receive a single associative array of Objects rather than enumerating each in the method signature. Why is it acceptable and commonly used in most popular frameworks for both of these languages to do this? Is there some justification beyond wishing to have concise method signatures? I do see a benefit in this -- that the API could remain unchanged as new, optional parameters are added. But Javascript and PHP already allow for optional parameters in their method signatures. If anything, it seems like Java or another OO language would benefit from this more... and yet I rarely see this pattern there. What gives?

  Read the article

• Should i use partial classes as business layer when using entity framework?

  - by samsur

  I am working on a project using entity framework. Is it okay to use partial classes of the EF generated classes as the business layer. I am begining to think that this is how EF is intended to be used. I have attempted to use a DTO pattern and soon realized that i am just creating a bunch of mapping classes that is duplicating my effort and also a cause for more maintenance work and an additional layer. I want to use self-tracking-entities and pass the EF entities to all the layers. Please share your thoughts and ideas. Thanks

  Read the article

• c# EnumerateFiles wildcard returning non matches?

  - by Sam Underhill

  As a simplified example I am executing the following IEnumerable<string> files = Directory.EnumerateFiles(path, @"2010*.xml", SearchOption.TopDirectoryOnly).ToList(); In my results set I am getting a few files which do no match the file pattern. According to msdn searchPattern wildcard is "Zero or more characters" and not a reg ex. An example is that I am getting a file name back as "2004_someothername.xml". For information there are in excess of 25,000 files in the folder. Does anyone have any idea what is going on?

  Read the article

< Previous Page | 199 200 201 202 203 204 205 206 207 208 209 210  | Next Page >