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  • Understanding pattern matching with cons operator

    - by Mathias
    In "Programming F#" I came across a pattern-matching like this one (I simplified a bit): let rec len list = match list with | [] -> 0 | [_] -> 1 | head :: tail -> 1 + len tail;; Practically, I understand that the last match recognizes the head and tail of the list. Conceptually, I don't get why it works. As far as I understand, :: is the cons operator, which appends a value in head position of a list, but it doesn't look to me like it is being used as an operator here. Should I understand this as a "special syntax" for lists, where :: is interpreted as an operator or a "match pattern" depending on context? Or can the same idea be extended for types other than lists, with other operators?

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  • Better to use constructor or method factory pattern?

    - by devoured elysium
    I have a wrapper class for the Bitmap .NET class called BitmapZone. Assuming we have a WIDTH x HEIGHT bitmap picture, this wrapper class should serve the purpose of allowing me to send to other methods/classes itself instead of the original bitmap. I can then better control what the user is or not allowed to do with the picture (and I don't have to copy the bitmap lots of times to send for each method/class). My question is: knowing that all BitmapZone's are created from a Bitmap, what do you find preferrable? Constructor syntax: something like BitmapZone bitmapZone = new BitmapZone(originalBitmap, x, y, width, height); Factory Method Pattern: BitmapZone bitmapZone = BitmapZone.From(originalBitmap, x , y, width, height); Factory Method Pattern: BitmapZone bitmapZone = BitmapZone.FromBitmap(originalBitmap, x, y, width, height); Other? Why? Thanks

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  • When to use the Flyweight Pattern

    - by elmt
    So I've just gotten on the boost train and was checking out the flyweight pattern and was interested in implementing it in my project. Obviously, it doesn't make sense to use it on any class that has only has one instance of it. However, say I have 5 instances of an class. Should I be using the flyweight pattern or should it be only used for a class that has at least N instances. I realize that many factors will influence this answer (how many fields there are, the size of the fields, etc.).

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  • Problem with literal arguments in the PATTERN string for a python 2to3 fixer

    - by Zxaos
    Hi folks. I'm writing a fixer for the 2to3 tool in python. In my pattern string, I have a section where I'd like to match an empty string as an argument, or an empty unicode string. The relevant chunk of my pattern looks like: (args='""' | args='u""') My issue is the second option never matches. Even if it's alone, it won't match. However, if I simply say args=any and then output args, I can catch cases where args is exactly equal to the second option. Is there some weird unicode handling thing going on? Why won't the second literal option ever match?

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  • Matching Line Boundaries in a Regular Expression (Pattern.MULTILINE/(?m)) is broken in Java?

    - by Mister M. Bean
    The example on http://www.exampledepot.com/egs/java.util.regex/Line.html gives false for me twice but should'nt! Why? CharSequence inputStr = "abc\ndef"; String patternStr = "abc$"; // Compile with multiline enabled Pattern pattern = Pattern.compile(patternStr, Pattern.MULTILINE); Matcher matcher = pattern.matcher(inputStr); boolean matchFound = matcher.find(); // true // Use an inline modifier to enable multiline mode matchFound = pattern.matches(".*abc$.*", "abc\r\ndef"); // false System.out.println(matchFound); // false matchFound = pattern.matches("(?m).*abc$.*", "abc\r\ndef"); // true System.out.println(matchFound);// false !!!!!

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  • sed find pattern on line with another pattern

    - by user2962390
    I am trying to extract text from a file between a '<' and a '', but only on a line starting with another specific pattern. So in a file that looks like: XXX Something here XXX Something more here XXX <\Lines like this are a problem ZZZ something <\This is the text I need XXX Don't need any of this I would like to print only the "<\This is the text I need". If I do sed -n '/^ZZZ/p' FILENAME it pulls the correct lines I need to look at, but obviously prints the whole line. sed -n '/</,//p' FILENAME prints way too much. I have looked into grouping and tried sed -n '/^ZZZ/{/</,//} FILENAME but this doesn't seem to work at all. Any suggestions? They will be much appreciated. (Apologies for formatting, never posted on here before)

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  • Better Understand the 'Strategy' Design Pattern

    - by Imran Omar Bukhsh
    Greetings Hope you all are doing great. I have been interested in design patterns for a while and started reading 'Head First Design Patterns'. I started with the first pattern called the 'Strategy' pattern. I went through the problem outlined in the images below and first tried to propose a solution myself so I could really grasp the importance of the pattern. So my question is that why is my solution ( below ) to the problem outlined in the images below not good enough. What are the good / bad points of my solution vs the pattern? What makes the pattern clearly the only viable solution ? Thanks for you input, hope it will help me better understand the pattern. MY SOLUTION Parent Class: DUCK <?php class Duck { public $swimmable; public $quackable; public $flyable; function display() { echo "A Duck Looks Like This<BR/>"; } function quack() { if($this->quackable==1) { echo("Quack<BR/>"); } } function swim() { if($this->swimmable==1) { echo("Swim<BR/>"); } } function fly() { if($this->flyable==1) { echo("Fly<BR/>"); } } } ?> INHERITING CLASS: MallardDuck <?php class MallardDuck extends Duck { function MallardDuck() { $this->quackable = 1; $this->swimmable = 1; } function display() { echo "A Mallard Duck Looks Like This<BR/>"; } } ?> INHERITING CLASS: WoddenDecoyDuck <?php class WoddenDecoyDuck extends Duck { function woddendecoyduck() { $this->quackable = 0; $this->swimmable = 0; } function display() { echo "A Wooden Decoy Duck Looks Like This<BR/>"; } } Thanking you for your input. Imran

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  • Data structure for pattern matching.

    - by alvonellos
    Let's say you have an input file with many entries like these: date, ticker, open, high, low, close, <and some other values> And you want to execute a pattern matching routine on the entries(rows) in that file, using a candlestick pattern, for example. (See, Doji) And that pattern can appear on any uniform time interval (let t = 1s, 5s, 10s, 1d, 7d, 2w, 2y, and so on...). Say a pattern matching routine can take an arbitrary number of rows to perform an analysis and contain an arbitrary number of subpatterns. In other words, some patterns may require 4 entries to operate on. Say also that the routine (may) later have to find and classify extrema (local and global maxima and minima as well as inflection points) for the ticker over a closed interval, for example, you could say that a cubic function (x^3) has the extrema on the interval [-1, 1]. (See link) What would be the most natural choice in terms of a data structure? What about an interface that conforms a Ticker object containing one row of data to a collection of Ticker so that an arbitrary pattern can be applied to the data. What's the first thing that comes to mind? I chose a doubly-linked circular linked list that has the following methods: push_front() push_back() pop_front() pop_back() [] //overloaded, can be used with negative parameters But that data structure seems very clumsy, since so much pushing and popping is going on, I have to make a deep copy of the data structure before running an analysis on it. So, I don't know if I made my question very clear -- but the main points are: What kind of data structures should be considered when analyzing sequential data points to conform to a pattern that does NOT require random access? What kind of data structures should be considered when classifying extrema of a set of data points?

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  • Name for Osherove's modified singleton pattern?

    - by Kazark
    I'm pretty well sold on the "singletons are evil" line of thought. Nevertheless, there are limited occurrences when you want to limit the creation of an object. Roy Osherove advises, If you're planning to use a singleton in your design, separate the logic of the singleton class and the logic that makes it a singleton (the part that initializes a static variables, for example) into two separate classes. That way, you can keep the single responsibility principle (SRP) and also have a way to override singleton logic. (The Art of Unit Testing 261-262) This pattern still perpetuates the global state. However, it does result in a testable design, so it seems to me to be a good pattern for mitigating the damage of a singleton. However, Osherove does not give a name to this pattern; but naming a pattern, according to the Gang of Four, is important: Naming a pattern immediately increases our design vocabulary. It lets us design at a higher level of abstraction. (3) Is there a standard name for this pattern? It seems different enough from a standard singleton to deserve a separate name. Decoupled Singleton, perhaps?

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  • LUA: A couple of pattern matching issues

    - by Josh
    I'm fairly new to lua programming, but I'm also a quick study. I've been working on a weather forecaster for a program that I use, and it's working well, for the most part. Here is what I have so far. (Pay no attention to the zs.stuff. That is program specific and has no bearing on the lua coding.) if not http then http = require("socket.http") end local locale = string.gsub(zs.params(1),"%s+","%%20") local page = http.request("http://www.wunderground.com/cgi-bin/findweather/getForecast?query=" .. locale .. "&wuSelect=WEATHER") local location = string.match(page,'title="([%w%s,]+) RSS"') --print("Gathering weather information for " .. location .. ".") --local windspeed = string.match(page,'<span class="nobr"><span class="b">([%d.]+)</span>&nbsp;mph</span>') --print(windspeed) local condition = string.match(page, '<td class="vaM taC"><img src="http://icons-ecast.wxug.com/i/c/a/[%w_]+.gif" width="42" height="42" alt="[%w%s]+" class="condIcon" />') --local image = string.match(page, '<img src="http://icons-ecast.wxug.com/i/c/a/(.+).gif" width="42" height="42" alt="[%w%s]+" class="condIcon" />') local temperature = string.match(page,'pwsvariable="tempf" english="&deg;F" metric="&deg;C" value="([%d.]+)">') local humidity = string.match(page,'pwsvariable="humidity" english="" metric="" value="(%d+)"') zs.say(location) --zs.say("image ./Images/" .. image .. ".gif") zs.say("<color limegreen>Condition:</color> <color white>" .. condition .. "</color>") zs.say("<color limegreen>Temperature: </color><color white>" .. temperature .. "F</color>") zs.say("<color limegreen>Humidity: </color><color white>" .. humidity .. "%</color>") My main issue is this: I changed the 'condition' and added the 'image' variables to what they are now. Even though the line it's supposed to be matching comes directly from the webpage, it fails to match at all. So I'm wondering what it is I'm missing that's preventing this code from working. If I take out the <td class="vaM taC">< img src="http://icons-ecast.wxug.com/i/c/a/[%w_]+.gif" it'll match condition flawlessly. (For whatever reason, I can't get the above line to display correctly, but there is no space between the `< and img) Can anyone point out what is wrong with it? Aside from the pattern matching, I assure you the line is verbatim from the webpage. Another question I had is the ability to match across line breaks. Is there any possible way to do this? The reason why I ask is because on that same page, a few of the things I need to match are broken up on separate lines, and since the actual pattern I'm wanting to match shows up in other places on the page, I need to be able to match across line breaks to get the exact pattern. I appreciate any help in this matter!

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  • Linq to SQL and concurrency with Rob Conery repository pattern

    - by David Hall
    I have implemented a DAL using Rob Conery's spin on the repository pattern (from the MVC Storefront project) where I map database objects to domain objects using Linq and use Linq to SQL to actually get the data. This is all working wonderfully giving me the full control over the shape of my domain objects that I want, but I have hit a problem with concurrency that I thought I'd ask about here. I have concurrency working but the solution feels like it might be wrong (just one of those gitchy feelings). The basic pattern is: private MyDataContext _datacontext private Table _tasks; public Repository(MyDataContext datacontext) { _dataContext = datacontext; } public void GetTasks() { _tasks = from t in _dataContext.Tasks; return from t in _tasks select new Domain.Task { Name = t.Name, Id = t.TaskId, Description = t.Description }; } public void SaveTask(Domain.Task task) { Task dbTask = null; // Logic for new tasks omitted... dbTask = (from t in _tasks where t.TaskId == task.Id select t).SingleOrDefault(); dbTask.Description = task.Description, dbTask.Name = task.Name, _dataContext.SubmitChanges(); } So with that implementation I've lost concurrency tracking because of the mapping to the domain task. I get it back by storing the private Table which is my datacontext list of tasks at the time of getting the original task. I then update the tasks from this stored Table and save what I've updated This is working - I get change conflict exceptions raised when there are concurrency violations, just as I want. However, it just screams to me that I've missed a trick. Is there a better way of doing this? I've looked at the .Attach method on the datacontext but that appears to require storing the original version in a similar way to what I'm already doing. I also know that I could avoid all this by doing away with the domain objects and letting the Linq to SQL generated objects all the way up my stack - but I dislike that just as much as I dislike the way I'm handling concurrency.

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  • preg_match , pattern, php

    - by Michael
    I'm trying to extract some specific pictures from html content . Currently I have the following array [1] = Array ( [0] = BuEZm5g!Wk~$(KGrHqQH-DgEvrb2CLuOBL-vbkHlKw~~_14.JPG#!BuEZm5g!Wk~$(KGrHqQH-DgEvrb2CLuOBL-vbkHlKw~~_12.JPG|1#http://i.ebayimg.com/08#!BuEZqMQBGk~$(KGrHqQH-DoEvrKYSoPiBL-vb)WgLw~~_14.JPG#!BuEZqMQBGk~$(KGrHqQH-DoEvrKYSoPiBL-vb)WgLw~~_12.JPG|2#http://i.ebayimg.com/13#!BuEZtkw!2k~$(KGrHqYH-EYEvsh4EjJSBL-vb-bLow~~_14.JPG#!BuEZtkw!2k~$(KGrHqYH-EYEvsh4EjJSBL-vb-bLow~~_12.JPG|3#http://i.ebayimg.com/03#!BuEZ)!wEGk~$(KGrHqYH-DwEvq8Z1JuQBL-vcMOoFQ~~_14.JPG#!BuEZ)!wEGk~$(KGrHqYH-DwEvq8Z1JuQBL-vcMOoFQ~~_12.JPG|4#http://i.ebayimg.com/09#!BuEZ1IQEGk~$(KGrHqEH-D0EvqwClvviBL-vcclJwg~~_14.JPG#!BuEZ1IQEGk~$(KGrHqEH-D0EvqwClvviBL-vcclJwg~~_12.JPG|5#http://i.ebayimg.com/17#!BuEZ4FQCWk~$(KGrHqUH-DMEvS+,FRj5BL-vco)Qgg~~_14.JPG#!BuEZ4FQCWk~$(KGrHqUH-DMEvS+,FRj5BL-vco)Qgg~~_12.JPG|6#http://i.ebayimg.com/17#!BuEZ7FQEWk~$(KGrHqYH-EYEvsh4EjJSBL-vc1v2Hg~~_14.JPG#!BuEZ7FQEWk~$(KGrHqYH-EYEvsh4EjJSBL-vc1v2Hg~~_12.JPG|7#http://i.ebayimg.com/12#!BuEZ-c!Bmk~$(KGrHqQH-CYEvr5z9)NVBL-vdC,)Mg~~_14.JPG#!BuEZ-c!Bmk~$(KGrHqQH-CYEvr5z9)NVBL-vdC,)Mg~~_12.JPG|8#http://i.ebayimg.com/20#!BuE,CNgCWk~$(KGrHqIH-CIEvqKBurmhBL-vdRBe3!~~_14.JPG#!BuE,CNgCWk~$(KGrHqIH-CIEvqKBurmhBL-vdRBe3!~~_12.JPG|9#http://i.ebayimg.com/24#!BuE,FN!EWk~$(KGrHqUH-C0EvsBdjbv0BL-vdeFkD!~~_14.JPG#!BuE,FN!EWk~$(KGrHqUH-C0EvsBdjbv0BL-vdeFkD!~~_12.JPG|10#http://i.ebayimg.com/16#!BuE,IOgBmk~$(KGrHqEH-EMEvpym7mSLBL-vdqI6nw~~_14.JPG#!BuE,IOgBmk~$(KGrHqEH-EMEvpym7mSLBL-vdqI6nw~~ ) I need to extract only the pictures that start with ! and ends in 12.JPG . An example of expected result is !BuEZm5g!Wk~$(KGrHqQH-DgEvrb2CLuOBL-vbkHlKw~~_12.JPG . I have a pattern but it doesn't work for some reasons that I don't know . It is $pattern = "/#\!(.*)_12.JPG/"; Thank you in advance for any help

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  • Database migration pattern for Java?

    - by Eno
    Im working on some database migration code in Java. Im also using a factory pattern so I can use different kinds of databases. And each kind of database im using implements a common interface. What I would like to do is have a migration check that is internal to the class and runs some database schema update code automatically. The actual update is pretty straight forward (I check schema version in a table and compare against a constant in my app to decide whether to migrate or not and between which versions of schema). To make this automatic I was thinking the test should live inside (or be called from) the constructor. OK, fair enough, that's simple enough. My problem is that I dont want the test to run every single time I instantiate a database object (it runs a query so having it run on every construction is not efficient). So maybe this should be a class static method? I guess my question is, what is a good design pattern for this type of problem? There ought to be a clean way to ensure the migration test runs only once OR is super-efficient.

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  • Need help make these classes use Visitor Pattern and generics

    - by Shervin
    Hi. I need help to generify and implement the visitor pattern. We are using tons of instanceof and it is a pain. I am sure it can be modified, but I am not sure how to do it. Basically we have an interface ProcessData public interface ProcessData { public setDelegate(Object delegate); public Object getDelegate(); //I am sure these delegate methods can use generics somehow } Now we have a class ProcessDataGeneric that implements ProcessData public class ProcessDataGeneric implements ProcessData { private Object delegate; public ProcessDataGeneric(Object delegate) { this.delegate = delegate; } } Now a new interface that retrieves the ProcessData interface ProcessDataWrapper { public ProcessData unwrap(); } Now a common abstract class that implements the wrapper so ProcessData can be retrieved @XmlSeeAlso( { ProcessDataMotorferdsel.class,ProcessDataTilskudd.class }) public abstract class ProcessDataCommon implements ProcessDataWrapper { protected ProcessData unwrapped; public ProcessData unwrap() { return unwrapped; } } Now the implementation public class ProcessDataMotorferdsel extends ProcessDataCommon { public ProcessDataMotorferdsel() { unwrapped = new ProcessDataGeneric(this); } } similarly public class ProcessDataTilskudd extends ProcessDataCommon { public ProcessDataTilskudd() { unwrapped = new ProcessDataGeneric(this); } } Now when I use these classes, I always need to do instanceof ProcessDataCommon pdc = null; if(processData.getDelegate() instanceof ProcessDataMotorferdsel) { pdc = (ProcessDataMotorferdsel) processData.getDelegate(); } else if(processData.getDelegate() instanceof ProcessDataTilskudd) { pdc = (ProcessDataTilskudd) processData.getDelegate(); } I know there is a better way to do this, but I have no idea how I can utilize Generics and the Visitor Pattern. Any help is GREATLY appreciated.

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  • JavaScript Module Pattern - What about using "return this"?

    - by Rob
    After doing some reading about the Module Pattern, I've seen a few ways of returning the properties which you want to be public. One of the most common ways is to declare your public properties and methods right inside of the "return" statement, apart from your private properties and methods. A similar way (the "Revealing" pattern) is to provide simply references to the properties and methods which you want to be public. Lastly, a third technique I saw was to create a new object inside your module function, to which you assign your new properties before returning said object. This was an interesting idea, but requires the creation of a new object. So I was thinking, why not just use "this.propertyName" to assign your public properties and methods, and finally use "return this" at the end? This way seems much simpler to me, as you can create private properties and methods with the usual "var" or "function" syntax, or use the "this.propertyName" syntax to declare your public methods. Here's the method I'm suggesting: (function() { var privateMethod = function () { alert('This is a private method.'); } this.publicMethod = function () { alert('This is a public method.'); } return this; })(); Are there any pros/cons to using the method above? What about the others?

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  • Scheme: Mysterious void in pattern match.

    - by Schemer
    Hi. I am writing a function called annotate that uses match-lambda -- often with recursive calls to annotate. Here is one of the pattern matches: (`(lambda (,<param1> . ,<params>) ,<stmts>) `(CLOSURE ENV (,<param1> . ,<params>) (lambda (ENV) ,(map annotate (map (lambda (x) (append `(,<param1> . ,<params>) (list x))) `(,<stmts>)))))) However, when this pattern is matched this is what returns: '(CLOSURE ENV (x) (lambda (ENV) ((CLOSURE ENV (x y) (lambda (ENV) ((+ x y)))))) #<void>) Specifically I can't figure out where "void" is coming from. In fact, if I include the line: ,(displayln (map annotate (map (lambda (x) (append `(,<param1> . ,<params>) (list x))) `(,<stmts>)))) it prints: ((CLOSURE ENV (x y) (lambda (ENV) ((+ x y))))) notably without "void". If someone could tell me what the problem is it would be greatly appreciated. Thanks.

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  • Repository Pattern Standardization of methods

    - by Nix
    All I am trying to find out the correct definition of the repository pattern. My original understanding was this (extremely dubmed down) Separate your Business Objects from your Data Objects Standardize access methods in data access layer. I have really seen 2 different implementations. Implementation 1 : public Interface IRepository<T>{ List<T> GetAll(); void Create(T p); void Update(T p); } public interface IProductRepository: IRepository<Product> { //Extension methods if needed List<Product> GetProductsByCustomerID(); } Implementation 2 : public interface IProductRepository { List<Product> GetAllProducts(); void CreateProduct(Product p); void UpdateProduct(Product p); List<Product> GetProductsByCustomerID(); } Notice the first is generic Get/Update/GetAll, etc, the second is more of what I would define "DAO" like. Both share an extraction from your data entities. Which I like, but i can do the same with a simple DAO. However the second piece standardize access operations I see value in, if you implement this enterprise wide people would easily know the set of access methods for your repository. Am I wrong to assume that the standardization of access to data is an integral piece of this pattern ? Rhino has a good article on implementation 1, and of course MS has a vague definition and an example of implementation 2 is here.

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  • Creating Entity Framework objects with Unity for Unit of Work/Repository pattern

    - by TobyEvans
    Hi there, I'm trying to implement the Unit of Work/Repository pattern, as described here: http://blogs.msdn.com/adonet/archive/2009/06/16/using-repository-and-unit-of-work-patterns-with-entity-framework-4-0.aspx This requires each Repository to accept an IUnitOfWork implementation, eg an EF datacontext extended with a partial class to add an IUnitOfWork interface. I'm actually using .net 3.5, not 4.0. My basic Data Access constructor looks like this: public DataAccessLayer(IUnitOfWork unitOfWork, IRealtimeRepository realTimeRepository) { this.unitOfWork = unitOfWork; this.realTimeRepository = realTimeRepository; } So far, so good. What I'm trying to do is add Dependency Injection using the Unity Framework. Getting the EF data context to be created with Unity was an adventure, as it had trouble resolving the constructor - what I did in the end was to create another constructor in my partial class with a new overloaded constructor, and marked that with [InjectionConstructor] [InjectionConstructor] public communergyEntities(string connectionString, string containerName) :this() { (I know I need to pass the connection string to the base object, that can wait until once I've got all the objects initialising correctly) So, using this technique, I can happily resolve my entity framework object as an IUnitOfWork instance thus: using (IUnityContainer container = new UnityContainer()) { container.RegisterType<IUnitOfWork, communergyEntities>(); container.Configure<InjectedMembers>() .ConfigureInjectionFor<communergyEntities>( new InjectionConstructor("a", "b")) DataAccessLayer target = container.Resolve<DataAccessLayer>(); Great. What I need to do now is create the reference to the repository object for the DataAccessLayer - the DAL only needs to know the interface, so I'm guessing that I need to instantiate it as part of the Unity Resolve statement, passing it the appropriate IUnitOfWork interface. In the past, I would have just passed the Repository constructor the db connection string, and it would have gone away, created a local Entity Framework object and used that just for the lifetime of the Repository method. This is different, in that I create an Entity Framework instance as an IUnitOfWork implementation during the Unity Resolve statement, and it's that instance I need to pass into the constructor of the Repository - is that possible, and if so, how? I'm wondering if I could make the Repository a property and mark it as a Dependency, but that still wouldn't solve the problem of how to create the Repository with the IUnitOfWork object that the DAL is being Resolved with I'm not sure if I've understood this pattern correctly, and will happily take advice on the best way to implement it - Entity Framework is staying, but Unity can be swapped out if not the best approach. If I've got the whole thing upside down, please tell me thanks

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  • ASP.NET MVC ViewModel Pattern

    - by Omu
    EDIT: I made something much better to fill and read data from a view using ViewModels, called it ValueInjecter. http://valueinjecter.codeplex.com/documentation using the ViewModel to store the mapping logic was not such a good idea because there was repetition and SRP violation, but now with the ValueInjecter I have clean ViewModels and dry mapping code I made a ViewModel pattern for editing stuff in asp.net mvc this pattern is usefull when you have to make a form for editing an entity and you have to put on the form some dropdowns for the user to choose some values public class OrganisationViewModel { //paramterless constructor required, cuz we are gonna get an OrganisationViewModel object from the form in the post save method public OrganisationViewModel() : this(new Organisation()) {} public OrganisationViewModel(Organisation o) { Organisation = o; Country = new SelectList(LookupFacade.Country.GetAll(), "ID", "Description", CountryKey); } //that's the Type for whom i create the viewmodel public Organisation Organisation { get; set; } #region DropDowns //for each dropdown i have a int? Key that stores the selected value public IEnumerable<SelectListItem> Country { get; set; } public int? CountryKey { get { if (Organisation.Country != null) { return Organisation.Country.ID; } return null; } set { if (value.HasValue) { Organisation.Country = LookupFacade.Country.Get(value.Value); } } } #endregion } and that's how i use it public ViewResult Edit(int id) { var model = new OrganisationViewModel(organisationRepository.Get(id)); return View(model); } [AcceptVerbs(HttpVerbs.Post)] public ActionResult Edit(OrganisationViewModel model) { organisationRepository.SaveOrUpdate(model.Organisation); return RedirectToAction("Index"); } and the markup <p> <label for="Name"> Name:</label> <%= Html.Hidden("Organisation.ID", Model.Organisation.ID)%> <%= Html.TextBox("Organisation.Name", Model.Organisation.Name)%> <%= Html.ValidationMessage("Organisation.Name", "*")%> </p> <p> ... <label for="CountryKey"> Country:</label> <%= Html.DropDownList("CountryKey", Model.Country, "please select") %> <%= Html.ValidationMessage("CountryKey", "*") %> </p> so tell me what you think about it

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  • Refactor Regex Pattern - Java

    - by UK
    Hello All, I have the following aaaa_bb_cc string to match and written a regex pattern like \\w{4}+\\_\\w{2}\\_\\w{2} and it works. Is there any simple regex which can do this same ?

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