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  • WebLogic Server 11gR1 Interactive Quick Reference

    - by JuergenKress
    The WebLogic Server 11gR1 Administration interactive quick reference is a multimedia tool for various terms and concepts used in WebLogic Server architecture. This tool is available for administrators for online or offline use. This is built as a multimedia web page which provides descriptions of WebLogic Server Architectural components, and references to relevant documentation. This tool offers valuable reference information for any complex concept or product in an intuitive and useful manner. Each interactive type presents data that may be available in the documentation (in the case of Oracle products), but presents it in a way that is more intuitive and useful to a user of Oracle products because it displays data the way it is used in a real world, best practice scenario. For example, the architectural diagram interactive type provides an image of an architectural diagram that is typically larger than a single slide or paper. The image is scrollable and provides zoom capabilities to easily and clearly view any part of the image. The image itself contains a hotspot map that you can click to get more information about a feature, including reference links to the documentation in question. Linking the visual image of the component and where it fits in the overall architecture of the product, or technology in use, to the technical explanation and how-to materials related to that component is something not offered by the documentation. In a future release, the poster will also enable you to drill down even further into the individual subsystems in nested diagrams to look at the details of that subsystem. In short, the interactive posters are good at showing you the big picture, then quickly and easily getting you to the detailed information you need. In an instant, you can see where a technical component fits into an overall architecture, and zero in on the nitty-gritty details that show you how to do it yourself. Note: This is a first initial release with more features in development. Currently known information: Only Firefox 8.0 and higher is known to work with this product. This product may work with Chrome and Safari browsers, but is known to have issues in Internet Explorer at this time. Smartphones, such as iPads and iPhones, are partially supported WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. BlogTwitterLinkedInMixForumWiki Technorati Tags: WebLogic server quick reference,weblogic overview,weblogic 12c,WebLogic Community,Oracle,OPN,Jürgen Kress

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  • Sortie des spécifications d'OpenCL 1.2 : séparation compilation/linkage, partitionnement et support de nouveaux types de périphériques

    Sortie des spécifications d'OpenCL 1.2 Séparation compilation/linkage, partitionnement et support de nouveaux types de périphérique Le groupe Khronos vient de ratifier et publier les spécifications d'OpenCL 1.2 (Open Computing Language), l'API et extension standardisée du langage C pour supporter le développement sur GPU et la programmation parallèle distribuée sur plusieurs types de processeurs compatibles. Parmi les nouveautés de cette version, citons : Le partitionnement des périphériques permet de diviser un périphérique en plusieurs sous-périphériques pour contrôler directement les tâches assignées à chaque unité de calcul ; Séparation de la compilation et ...

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  • Control of File Types in Ubuntu

    <b>Packt:</b> "In this article by Delan Azabani, you'll learn how Ubuntu identifies file types, how to use Assogiate to control these processes, using Ubuntu Tweak to associate types with applications and use Bless to inspect binary files."

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  • Types in Lisp and Scheme

    - by user2054900
    I see now that Racket has types. At first glance it seems to be almost identical to Haskell typing. But is Lisp's CLOS covering some of the space Haskell types cover? Creating a very strict Haskell type and an object in any OO language seems vaguely similar. It's just that I've drunk some of the Haskell kool-aid and I'm totally paranoid that if I go down the Lisp road, I'll be screwed due to dynamic typing.

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  • How to get around the Circular Reference issue with JSON and Entity

    - by DanScan
    I have been experimenting with creating a website that leverages MVC with JSON for my presentation layer and Entity framework for data model/database. My Issue comes into play with serializing my Model objects into JSON. I am using the code first method to create my database. When doing the code first method a one to many relationship (parent/child) requires the child to have a reference back to the parent. (Example code my be a typo but you get the picture) class parent { public List<child> Children{get;set;} public int Id{get;set;} } class child { public int ParentId{get;set;} [ForeignKey("ParentId")] public parent MyParent{get;set;} public string name{get;set;} } When returning a "parent" object via a JsonResult a circular reference error is thrown because "child" has a property of class parent. I have tried the ScriptIgnore attribute but I lose the ability to look at the child objects. I will need to display information in a parent child view at some point. I have tried to make base classes for both parent and child that do not have a circular reference. Unfortunately when I attempt to send the baseParent and baseChild these are read by the JSON Parser as their derived classes (I am pretty sure this concept is escaping me). Base.baseParent basep = (Base.baseParent)parent; return Json(basep, JsonRequestBehavior.AllowGet); The one solution I have come up with is to create "View" Models. I create simple versions of the database models that do not include the reference to the parent class. These view models each have method to return the Database Version and a constructor that takes the database model as a parameter (viewmodel.name = databasemodel.name). This method seems forced although it works. NOTE:I am posting here because I think this is more discussion worthy. I could leverage a different design pattern to over come this issue or it could be as simple as using a different attribute on my model. In my searching I have not seen a good method to overcome this problem. My end goal would be to have a nice MVC application that heavily leverages JSON for communicating with the server and displaying data. While maintaining a consistant model across layers (or as best as I can come up with).

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  • Return cell reference as result of if statement with vlookups.

    - by EMJ
    I have two sets of data in excel. One contains a set of data which represents the initial step of a process. The other set of data represents the additional steps which take place after the first step is completed. Each of the data records in the "additional step data" has an id in a column. I need to find the identifying codes of the "additional step data" which correspond with the initial step data records. The problem is that I have to match the data in 4 columns between the two data sets and return the id of the "additional step data". I started by doing a combination of an if and vlookup functions, but I got stuck when I tried to figure out how to get the if statement to reference the id of the matching "additional step data". Basically I am trying to avoid having to search by manually filtering between two sets of data and finding corresponding records. Does anyone have any idea about how to do this?

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  • Compiling Ubuntu server: "libQtGui.so: undefined reference to png functions" errors

    - by Kowalikus
    I want to compile wkhtmltopdf on Ubuntu Server, but I have a problem with following errors: /usr/lib/libQtGui.so: undefined reference to `png_read_info@PNG12_0' /usr/lib/libQtGui.so: undefined reference to `png_set_gAMA@PNG12_0' /usr/lib/libQtGui.so: undefined reference to `png_set_PLTE@PNG12_0' ... /usr/lib/libQtGui.so: undefined reference to `png_create_info_struct@PNG12_0' /usr/lib/libQtGui.so: undefined reference to `png_set_bgr@PNG12_0' /usr/lib/libQtGui.so: undefined reference to `png_get_valid@PNG12_0' What can I do? in /usr/lib lrwxrwxrwx 1 17 2010-02-17 15:00 libQtGui.so -> libQtGui.so.4.5.2 lrwxrwxrwx 1 17 2010-02-17 14:59 libQtGui.so.4 -> libQtGui.so.4.5.2 lrwxrwxrwx 1 17 2010-02-17 14:59 libQtGui.so.4.5 -> libQtGui.so.4.5.2 -rw-r--r-- 1 10071604 2009-10-14 23:34 libQtGui.so.4.5.2

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  • Compiling Ubuntu server: "libQtGui.so: undefined reference to png functions" errors

    - by Kowalikus
    I want to compile wkhtmltopdf on Ubuntu Server, but I have a problem with following errors: /usr/lib/libQtGui.so: undefined reference to `png_read_info@PNG12_0' /usr/lib/libQtGui.so: undefined reference to `png_set_gAMA@PNG12_0' /usr/lib/libQtGui.so: undefined reference to `png_set_PLTE@PNG12_0' ... /usr/lib/libQtGui.so: undefined reference to `png_create_info_struct@PNG12_0' /usr/lib/libQtGui.so: undefined reference to `png_set_bgr@PNG12_0' /usr/lib/libQtGui.so: undefined reference to `png_get_valid@PNG12_0' What can I do? in /usr/lib lrwxrwxrwx 1 17 2010-02-17 15:00 libQtGui.so -> libQtGui.so.4.5.2 lrwxrwxrwx 1 17 2010-02-17 14:59 libQtGui.so.4 -> libQtGui.so.4.5.2 lrwxrwxrwx 1 17 2010-02-17 14:59 libQtGui.so.4.5 -> libQtGui.so.4.5.2 -rw-r--r-- 1 10071604 2009-10-14 23:34 libQtGui.so.4.5.2

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  • SQLAuthority News – Fast Track Data Warehouse 3.0 Reference Guide

    - by pinaldave
    http://msdn.microsoft.com/en-us/library/gg605238.aspx I am very excited that Fast Track Data Warehouse 3.0 reference guide has been announced. As a consultant I have always enjoyed working with Fast Track Data Warehouse project as it truly expresses the potential of the SQL Server Engine. Here is few details of the enhancement of the Fast Track Data Warehouse 3.0 reference architecture. The SQL Server Fast Track Data Warehouse initiative provides a basic methodology and concrete examples for the deployment of balanced hardware and database configuration for a data warehousing workload. Balance is measured across the key components of a SQL Server installation; storage, server, application settings, and configuration settings for each component are evaluated. Description Note FTDW 3.0 Architecture Basic component architecture for FT 3.0 based systems. New Memory Guidelines Minimum and maximum tested memory configurations by server socket count. Additional Startup Options Notes for T-834 and setting for Lock Pages in Memory. Storage Configuration RAID1+0 now standard (RAID1 was used in FT 2.0). Evaluating Fragmentation Query provided for evaluating logical fragmentation. Loading Data Additional options for CI table loads. MCR Additional detail and explanation of FTDW MCR Rating. Read white paper on fast track data warehousing. Reference: Pinal Dave (http://blog.SQLAuthority.com)   Filed under: Business Intelligence, Data Warehousing, PostADay, SQL, SQL Authority, SQL Documentation, SQL Download, SQL Query, SQL Server, SQL Tips and Tricks, SQL White Papers, SQLAuthority News, T SQL, Technology

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  • SQLAuthority News – Download SQL Server 2008 R2 Upgrade Technical Reference Guide

    - by pinaldave
    I recently come across very interesting white paper written for Microsoft by Solid Quality Mentors. A successful upgrade to SQL Server 2008 R2 should be smooth and trouble-free. To do that smooth transition, you must plan sufficiently for the upgrade and match the complexity of your database application. Otherwise, you risk costly and stressful errors and upgrade problems. SQL Server 2008 R2 Upgrade Technical Reference Guide is one of the best and comprehensive reference guide I have seen on the subject of SQL Server 2008 R2 upgrade. There are so many various subjects discussed about upgrade which one would always wanted to see. You can find the link of why one has to upgrade to SQL Server 2008 R2 over here: Why upgrade to SQL Server 2008 R2. White paper to upgrade to SQL Server 2008 R2 Upgrade Guide. Here is the quick list of content of the white paper. 1. Upgrade Planning and Deployment 2. Management and Development Tools 3. Relational Databases 4. High Availability 5. Database Security 6. Full-Text Search 7. Service Broker 8. Transact-SQL Queries 9. Notification Services 10. SQL Server Express 11. Analysis Services 12. Data Mining 13. Integration Services 14. Reporting Services 15. Other Microsoft Applications and Platforms Appendix 1: Version and Edition Upgrade Paths Appendix 2: Upgrade Planning Deployment and Tasks Checklist This white paper is indeed huge with 490 pages and 151,956 words.As I said, this is one of the most comprehensive white paper ever published on the subject. Just reading this white paper one can learn a lot about SQL Server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Documentation, SQL Download, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology

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  • LLVM-3.1 libLLVMSupport.a undefined reference to `dladdr'

    - by user91387
    I'm trying to compile using the llvm-3.1 package. I'm running 12.04 x64 (3.2.0-26 kernel) && 12.10 (3.5.0-4) x64 backported llvm-3.1 from quantal, then debian experimental. Next I tried 12.10 with the native ubuntu llvm-3.1 package; this failed as well. user@system:/tmp/llvm-test# make compiling cpp yacc file: decaf-llvm.y output file: decaf-llvm bison -b decaf-llvm -d decaf-llvm.y /bin/mv -f decaf-llvm.tab.c decaf-llvm.tab.cc flex -odecaf-llvm.lex.cc decaf-llvm.lex g++ -o ./decaf-llvm decaf-llvm.tab.cc decaf-llvm.lex.cc decaf-stdlib.c `llvm-config --cppflags --ldflags --libs core jit native` -ly -ll /usr/lib/llvm-3.1/lib/libLLVMSupport.a(Signals.o): In function `PrintStackTrace(void*)': (.text+0x6c): undefined reference to `dladdr' /usr/lib/llvm-3.1/lib/libLLVMSupport.a(Signals.o): In function `PrintStackTrace(void*)': (.text+0x18f): undefined reference to `dladdr' collect2: error: ld returned 1 exit status make: *** [decaf-llvm] Error 1 I know the code works as I've run it in centos fine using llvm-3.1-6.fc18(rpm) Google was a bit helpful with this: "On some systems, incluning Ubuntu 11.10, linking may fail with message that libLLVMSupport.a in function PrintStackTrace(void*) has undefined reference to dladdr." "Workaround is to compile LLVM with cmake specifying the following variable: -DCMAKE_EXE_LINKER_FLAGS=-ldl" http://svn.dsource.org/projects/bindings/trunk/llvm-3.0/Readme I double checked y ldflags and everything seems ok. user@system:/llvm-config --ldflags -L/usr/lib/llvm-3.1/lib -lpthread -lffi -ldl -lm I'm unclear of what to do next; any suggestions?

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  • SQLAuthority News – Presenting at Tech-Ed On Road – Ahmedabad – June 11, 2011 – Wait Types and Queues

    - by pinaldave
    I will be presenting in person on the subject SQL Server Wait Types and Queues at Ahmedabad on June 11, 2011. Here is the quick summary of the session. SQL Server Waits and Queues – Your Gateway to Perf. Troubleshooting Time: 11:15am – 12:15pm – June 11, 2011 Just like a horoscope, SQL Server Waits and Queues can reveal your past, explain your present and predict your future. SQL Server Performance Tuning uses the Waits and Queues as a proven method to identify the best opportunities to improve performance. A glance at Wait Types can tell where there is a bottleneck. Learn how to identify bottlenecks and potential resolutions in this fast paced, advanced performance tuning session. This session is based on my performance tuning Wait Types and Queues series. SQL SERVER – Summary of Month – Wait Type – Day 28 of 28 During the session there will be Quiz and those who gets right answer will get very interesting gifts from me. Do not miss a single minute of the event. We are also going to have two rock star speakers – Harish Vaidyanathan and Jacob Sebastian. Here is the details for the event: SQLAuthority News – Community Tech Days – TechEd on The Road – Ahmedabad – June 11, 2011 Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, T SQL, Technology

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  • What types of programming contest problems are there?

    - by Alex
    Basically, I want to make a great reference for use with programming contests that would have all of the algorithms that I can put together that I would need during a contest as well as sample useage for the code. I'm planning on making this into a sort of book that I could print off and take with me to competitions. I would like to do this rather than simply bringing other books (such as Algorithms books) because I think that I will learn a lot more by going over all of the algorithms myself as well as I would know exactly what I have in the book, making it more efficient to have and use. So, I've been doing research to determine what types of programming problems and algorithms are common on contests, and the only thing I can really find is this (which I have seen referenced a few times): Hal Burch conducted an analysis over spring break of 1999 and made an amazing discovery: there are only 16 types of programming contest problems! Furthermore, the top several comprise almost 80% of the problems seen at the IOI. Here they are: Dynamic Programming Greedy Complete Search Flood Fill Shortest Path Recursive Search Techniques Minimum Spanning Tree Knapsack Computational Geometry Network Flow Eulerian Path Two-Dimensional Convex Hull BigNums Heuristic Search Approximate Search Ad Hoc Problems The most challenging problems are Combination Problems which involve a loop (combinations, subsets, etc.) around one of the above algorithms - or even a loop of one algorithm with another inside it. These seem extraordinarily tricky to get right, even though conceptually they are ``obvious''. Now that's good and all, but that study was conducted in 1999, which was 13 years ago! One thing I know is that there are no BigNums problems any more (as Java has a BigInteger class, they have stopped making those problems). So, I'm wondering if anyone knows of any more recent studies of the types of problems that may be seen in a programming contest? Or what the most helpful algorithms on contests would be?

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  • Handling Types for Real and Complex Matrices in a BLAS Wrapper

    - by mga
    I come from a C background and I'm now learning OOP with C++. As an exercise (so please don't just say "this already exists"), I want to implement a wrapper for BLAS that will let the user write matrix algebra in an intuitive way (e.g. similar to MATLAB) e.g.: A = B*C*D.Inverse() + E.Transpose(); My problem is how to go about dealing with real (R) and complex (C) matrices, because of C++'s "curse" of letting you do the same thing in N different ways. I do have a clear idea of what it should look like to the user: s/he should be able to define the two separately, but operations would return a type depending on the types of the operands (R*R = R, C*C = C, R*C = C*R = C). Additionally R can be cast into C and vice versa (just by setting the imaginary parts to 0). I have considered the following options: As a real number is a special case of a complex number, inherit CMatrix from RMatrix. I quickly dismissed this as the two would have to return different types for the same getter function. Inherit RMatrix and CMatrix from Matrix. However, I can't really think of any common code that would go into Matrix (because of the different return types). Templates. Declare Matrix<T> and declare the getter function as T Get(int i, int j), and operator functions as Matrix *(Matrix RHS). Then specialize Matrix<double> and Matrix<complex>, and overload the functions. Then I couldn't really see what I would gain with templates, so why not just define RMatrix and CMatrix separately from each other, and then overload functions as necessary? Although this last option makes sense to me, there's an annoying voice inside my head saying this is not elegant, because the two are clearly related. Perhaps I'm missing an appropriate design pattern? So I guess what I'm looking for is either absolution for doing this, or advice on how to do better.

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  • Are specific types still necessary?

    - by MKO
    One thing that occurred to me the other day, are specific types still necessary or a legacy that is holding us back. What I mean is: do we really need short, int, long, bigint etc etc. I understand the reasoning, variables/objects are kept in memory, memory needs to be allocated and therefore we need to know how big a variable can be. But really, shouldn't a modern programming language be able to handle "adaptive types", ie, if something is only ever allocated in the shortint range it uses fewer bytes, and if something is suddenly allocated a very big number the memory is allocated accordinly for that particular instance. Float, real and double's are a bit trickier since the type depends on what precision you need. Strings should however be able to take upp less memory in many instances (in .Net) where mostly ascii is used buth strings always take up double the memory because of unicode encoding. One argument for specific types might be that it's part of the specification, ie for example a variable should not be able to be bigger than a certain value so we set it to shortint. But why not have type constraints instead? It would be much more flexible and powerful to be able to set permissible ranges and values on variables (and properties). I realize the immense problem in revamping the type architecture since it's so tightly integrated with underlying hardware and things like serialization might become tricky indeed. But from a programming perspective it should be great no?

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  • Announcing Oracle Retail Reference Model, Version 2.4

    - by Oracle Retail Documentation Team
    The Oracle Retail Reference Model (RRM) collection of established practice business processes has been updated and re-released as RRM, Version 2.4. A permanent link to the My Oracle Support Document ID, 1145264.1, is available on the right side of this blog, in the Bookmarks section. The Oracle Retail Retail Reference Model (RRM) business process designs are intended to support an implementation of the merchandising, stores, and planning products. These designs are a guide for both the business and implementation teams. They explain some scenarios and factors that need to be considered for a successful implementation. The designs are created for a generic retailer, with some considerations made for hardlines, apparel (softlines), grocery, and telecommunications. Oracle Retail Reference Model 2.4 Doc ID 1145264.1This release includes the following: Updates for particular Oracle Retail application releases since August 2011. Updates per feedback received from process users, including Advanced Inventory Planning flow additions. Improvements in the area of standardized role names and organizational units. Please send any questions, comments, and suggestions to [email protected].

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  • SQL SERVER – Summary of Month – Wait Type – Day 28 of 28

    - by pinaldave
    I am glad to announce that the month of Wait Types and Queues very successful. I am glad that it was very well received and there was great amount of participation from community. I am fortunate to have some of the excellent comments throughout the series. I want to dedicate this series to all the guest blogger – Jonathan, Jacob, Glenn, and Feodor for their kindness to take a participation in this series. Here is the complete list of the blog posts in this series. I enjoyed writing the series and I plan to continue writing similar series. Please offer your opinion. SQL SERVER – Introduction to Wait Stats and Wait Types – Wait Type – Day 1 of 28 SQL SERVER – Signal Wait Time Introduction with Simple Example – Wait Type – Day 2 of 28 SQL SERVER – DMV – sys.dm_os_wait_stats Explanation – Wait Type – Day 3 of 28 SQL SERVER – DMV – sys.dm_os_waiting_tasks and sys.dm_exec_requests – Wait Type – Day 4 of 28 SQL SERVER – Capturing Wait Types and Wait Stats Information at Interval – Wait Type – Day 5 of 28 SQL SERVER – CXPACKET – Parallelism – Usual Solution – Wait Type – Day 6 of 28 SQL SERVER – CXPACKET – Parallelism – Advanced Solution – Wait Type – Day 7 of 28 SQL SERVER – SOS_SCHEDULER_YIELD – Wait Type – Day 8 of 28 SQL SERVER – PAGEIOLATCH_DT, PAGEIOLATCH_EX, PAGEIOLATCH_KP, PAGEIOLATCH_SH, PAGEIOLATCH_UP – Wait Type – Day 9 of 28 SQL SERVER – IO_COMPLETION – Wait Type – Day 10 of 28 SQL SERVER – ASYNC_IO_COMPLETION – Wait Type – Day 11 of 28 SQL SERVER – PAGELATCH_DT, PAGELATCH_EX, PAGELATCH_KP, PAGELATCH_SH, PAGELATCH_UP – Wait Type – Day 12 of 28 SQL SERVER – FT_IFTS_SCHEDULER_IDLE_WAIT – Full Text – Wait Type – Day 13 of 28 SQL SERVER – BACKUPIO, BACKUPBUFFER – Wait Type – Day 14 of 28 SQL SERVER – LCK_M_XXX – Wait Type – Day 15 of 28 SQL SERVER – Guest Post – Jonathan Kehayias – Wait Type – Day 16 of 28 SQL SERVER – WRITELOG – Wait Type – Day 17 of 28 SQL SERVER – LOGBUFFER – Wait Type – Day 18 of 28 SQL SERVER – PREEMPTIVE and Non-PREEMPTIVE – Wait Type – Day 19 of 28 SQL SERVER – MSQL_XP – Wait Type – Day 20 of 28 SQL SERVER – Guest Posts – Feodor Georgiev – The Context of Our Database Environment – Going Beyond the Internal SQL Server Waits – Wait Type – Day 21 of 28 SQL SERVER – Guest Post – Jacob Sebastian – Filestream – Wait Types – Wait Queues – Day 22 of 28 SQL SERVER – OLEDB – Link Server – Wait Type – Day 23 of 28 SQL SERVER – 2000 – DBCC SQLPERF(waitstats) – Wait Type – Day 24 of 28 SQL SERVER – 2011 – Wait Type – Day 25 of 28 SQL SERVER – Guest Post – Glenn Berry – Wait Type – Day 26 of 28 SQL SERVER – Best Reference – Wait Type – Day 27 of 28 SQL SERVER – Summary of Month – Wait Type – Day 28 of 28 Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Optimization, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, SQLServer, T SQL, Technology

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  • ActionResult types in MVC2

    - by rajbk
    In ASP.NET MVC, incoming browser requests gets mapped to a controller action method. The action method returns a type of ActionResult in response to the browser request. A basic example is shown below: public class HomeController : Controller { public ActionResult Index() { return View(); } } Here we have an action method called Index that returns an ActionResult. Inside the method we call the View() method on the base Controller. The View() method, as you will see shortly, is a method that returns a ViewResult. The ActionResult class is the base class for different controller results. The following diagram shows the types derived from the ActionResult type. ASP.NET has a description of these methods ContentResult – Represents a text result. EmptyResult – Represents no result. FileContentResult – Represents a downloadable file (with the binary content). FilePathResult – Represents a downloadable file (with a path). FileStreamResult – Represents a downloadable file (with a file stream). JavaScriptResult – Represents a JavaScript script. JsonResult – Represents a JavaScript Object Notation result that can be used in an AJAX application. PartialViewResult – Represents HTML and markup rendered by a partial view. RedirectResult – Represents a redirection to a new URL. RedirectToRouteResult – Represents a result that performs a redirection by using the specified route values dictionary. ViewResult – Represents HTML and markup rendered by a view. To return the types shown above, you call methods that are available in the Controller base class. A list of these methods are shown below.   Methods without an ActionResult return type The MVC framework will translate action methods that do not return an ActionResult into one. Consider the HomeController below which has methods that do not return any ActionResult types. The methods defined return an int, object and void respectfully. public class HomeController : Controller { public int Add(int x, int y) { return x + y; }   public Employee GetEmployee() { return new Employee(); }   public void DoNothing() { } } When a request comes in, the Controller class hands internally uses a ControllerActionInvoker class which inspects the action parameters and invokes the correct action method. The CreateActionResult method in the ControllerActionInvoker class is used to return an ActionResult. This method is shown below. If the result of the action method is null, an EmptyResult instance is returned. If the result is not of type ActionResult, the result is converted to a string and returned as a ContentResult. protected virtual ActionResult CreateActionResult(ControllerContext controllerContext, ActionDescriptor actionDescriptor, object actionReturnValue) { if (actionReturnValue == null) { return new EmptyResult(); }   ActionResult actionResult = (actionReturnValue as ActionResult) ?? new ContentResult { Content = Convert.ToString(actionReturnValue, CultureInfo.InvariantCulture) }; return actionResult; }   In the HomeController class above, the DoNothing method will return an instance of the EmptyResult() Renders an empty webpage the GetEmployee() method will return a ContentResult which contains a string that represents the current object Renders the text “MyNameSpace.Controllers.Employee” without quotes. the Add method for a request of /home/add?x=3&y=5 returns a ContentResult Renders the text “8” without quotes. Unit Testing The nice thing about the ActionResult types is in unit testing the controller. We can, without starting a web server, create an instance of the Controller, call the methods and verify that the type returned is the expected ActionResult type. We can then inspect the returned type properties and confirm that it contains the expected values. Enjoy! Sulley: Hey, Mike, this might sound crazy but I don't think that kid's dangerous. Mike: Really? Well, in that case, let's keep it. I always wanted a pet that could kill me.

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  • WebGrid Helper and Complex Types

    - by imran_ku07
        Introduction:           WebGrid helper makes it very easy to show tabular data. It was originally designed for ASP.NET Web Pages(WebMatrix) to display, edit, page and sort tabular data but you can also use this helper in ASP.NET Web Forms and ASP.NET MVC. When using this helper, sometimes you may run into a problem if you use complex types in this helper. In this article, I will show you how you can use complex types in WebGrid helper.       Description:             Let's say you need to show the employee data and you have the following classes,   public class Employee { public string Name { get; set; } public Address Address { get; set; } public List<string> ContactNumbers { get; set; } } public class Address { public string City { get; set; } }               The Employee class contain a Name, an Address and list of ContactNumbers. You may think that you can easily show City in WebGrid using Address.City, but no. The WebGrid helper will throw an exception at runtime if any Address property is null in the Employee list. Also, you cannot directly show ContactNumbers property. The easiest way to show these properties is to add some additional properties,   public Address NotNullableAddress { get { return Address ?? new Address(); } } public string Contacts { get { return string.Join("; ",ContactNumbers); } }               Now you can easily use these properties in WebGrid. Here is the complete code of this example,  @functions{ public class Employee { public Employee(){ ContactNumbers = new List<string>(); } public string Name { get; set; } public Address Address { get; set; } public List<string> ContactNumbers { get; set; } public Address NotNullableAddress { get { return Address ?? new Address(); } } public string Contacts { get { return string.Join("; ",ContactNumbers); } } } public class Address { public string City { get; set; } } } @{ var myClasses = new List<Employee>{ new Employee { Name="A" , Address = new Address{ City="AA" }, ContactNumbers = new List<string>{"021-216452","9231425651"}}, new Employee { Name="C" , Address = new Address{ City="CC" }}, new Employee { Name="D" , ContactNumbers = new List<string>{"045-14512125","21531212121"}} }; var grid = new WebGrid(source: myClasses); } @grid.GetHtml(columns: grid.Columns( grid.Column("NotNullableAddress.City", header: "City"), grid.Column("Name"), grid.Column("Contacts")))                    Summary:           You can use WebGrid helper to show tabular data in ASP.NET MVC, ASP.NET Web Forms and  ASP.NET Web Pages. Using this helper, you can also show complex types in the grid. In this article, I showed you how you use complex types with WebGrid helper. Hopefully you will enjoy this article too.  

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  • Type checking and recursive types (Writing the Y combinator in Haskell/Ocaml)

    - by beta
    When explaining the Y combinator in the context of Haskell, it's usually noted that the straight-forward implementation won't type-check in Haskell because of its recursive type. For example, from Rosettacode [1]: The obvious definition of the Y combinator in Haskell canot be used because it contains an infinite recursive type (a = a -> b). Defining a data type (Mu) allows this recursion to be broken. newtype Mu a = Roll { unroll :: Mu a -> a } fix :: (a -> a) -> a fix = \f -> (\x -> f (unroll x x)) $ Roll (\x -> f (unroll x x)) And indeed, the “obvious” definition does not type check: ?> let fix f g = (\x -> \a -> f (x x) a) (\x -> \a -> f (x x) a) g <interactive>:10:33: Occurs check: cannot construct the infinite type: t2 = t2 -> t0 -> t1 Expected type: t2 -> t0 -> t1 Actual type: (t2 -> t0 -> t1) -> t0 -> t1 In the first argument of `x', namely `x' In the first argument of `f', namely `(x x)' In the expression: f (x x) a <interactive>:10:57: Occurs check: cannot construct the infinite type: t2 = t2 -> t0 -> t1 In the first argument of `x', namely `x' In the first argument of `f', namely `(x x)' In the expression: f (x x) a (0.01 secs, 1033328 bytes) The same limitation exists in Ocaml: utop # let fix f g = (fun x a -> f (x x) a) (fun x a -> f (x x) a) g;; Error: This expression has type 'a -> 'b but an expression was expected of type 'a The type variable 'a occurs inside 'a -> 'b However, in Ocaml, one can allow recursive types by passing in the -rectypes switch: -rectypes Allow arbitrary recursive types during type-checking. By default, only recursive types where the recursion goes through an object type are supported. By using -rectypes, everything works: utop # let fix f g = (fun x a -> f (x x) a) (fun x a -> f (x x) a) g;; val fix : (('a -> 'b) -> 'a -> 'b) -> 'a -> 'b = <fun> utop # let fact_improver partial n = if n = 0 then 1 else n*partial (n-1);; val fact_improver : (int -> int) -> int -> int = <fun> utop # (fix fact_improver) 5;; - : int = 120 Being curious about type systems and type inference, this raises some questions I'm still not able to answer. First, how does the type checker come up with the type t2 = t2 -> t0 -> t1? Having come up with that type, I guess the problem is that the type (t2) refers to itself on the right side? Second, and perhaps most interesting, what is the reason for the Haskell/Ocaml type systems to disallow this? I guess there is a good reason since Ocaml also will not allow it by default even if it can deal with recursive types if given the -rectypes switch. If these are really big topics, I'd appreciate pointers to relevant literature. [1] http://rosettacode.org/wiki/Y_combinator#Haskell

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  • Magento My Account Layout XML Problem

    - by Remy
    Hi there, I'm having issues getting the customer.xml layout file to work properly for the customer's "my account" pages. The navigation links and the previously ordered items that are usually on the left hand side of the page won't show up on the page, but if I change the reference name to "content" in the xml file, it shows up (except it's obviously then on the right hand side). I've checked the template it's referencing (2columns-left.phtml), and the getChildHtml('left') is there in the correct position. The block that's causing the problem: <customer_account> <!-- Mage_Customer --> <reference name="root"> <action method="setTemplate"><template>page/2columns-left.phtml</template></action> </reference> <reference name="left"> <action method="unsetChild"><name>catalog.navigation.all</name></action> <action method="unsetChild"><name>callout.sendcard</name></action> <action method="unsetChild"><name>callout.specialorder</name></action> <block type="customer/account_navigation" name="customer_account_navigation" before="-" template="customer/account/navigation.phtml"> <action method="addLink" translate="label" module="customer"><name>account</name><path>customer/account/</path><label>Account Dashboard</label></action> <action method="addLink" translate="label" module="customer"><name>account_edit</name><path>customer/account/edit/</path><label>Account Information</label></action> <action method="addLink" translate="label" module="customer"><name>address_book</name><path>customer/address/</path><label>Address Book</label></action> </block> <block type="sales/reorder_sidebar" name="sale.reorder.sidebar" as="reorder" template="sales/reorder/sidebar.phtml"/> <remove name="tags_popular"/> </reference> </customer_account> This was basically copied straight over from another one of our sites where this works 100%. I've tried everything I can think of (changing the name of the reference in both the template and the layout xml, for example) to no avail. The templates that the layout is referencing are obviously working because they do show up when put into the "content" area. This installation of magento is version 1.3.1.1. I appreciate any advice you have to give me... *Update: I tried changing the reference to "global_messages", and it doesn't show there either. It only seems to work in the "content" section.* Update 2: These are the results of using the "showLayout=page" query string on the page when used with Alan Storm's very handy debugging module (which you'll find in his answer below). <?xml version="1.0"?> <layout><block type="page/html" name="root" output="toHtml" template="page/3columns.phtml"> <block type="page/html_head" name="head" as="head"> <action method="addJs"> <script>prototype/prototype.js</script> </action> <action method="addJs"> <script>prototype/validation.js</script> </action> <action method="addJs"> <script>paypoint/validation.js</script> </action> <action method="addJs"> <script>scriptaculous/builder.js</script> </action> <action method="addJs"> <script>scriptaculous/effects.js</script> </action> <action method="addJs"> <script>scriptaculous/dragdrop.js</script> </action> <action method="addJs"> <script>scriptaculous/controls.js</script> </action> <action method="addJs"> <script>scriptaculous/slider.js</script> </action> <action method="addJs"> <script>varien/js.js</script> </action> <action method="addJs"> <script>varien/form.js</script> </action> <action method="addJs"> <script>varien/menu.js</script> </action> <action method="addJs"> <script>mage/translate.js</script> </action> <action method="addJs"> <script>mage/cookies.js</script> </action> <action method="addCss"> <stylesheet>css/reset.css</stylesheet> </action> <action method="addCss"> <stylesheet>css/boxes.css</stylesheet> </action> <action method="addCss"> <stylesheet>css/clears.css</stylesheet> </action> <action method="addCss"> <stylesheet>css/menu.css</stylesheet> </action> <action method="addCss"> <stylesheet>css/calendar-blue.css</stylesheet> </action> <action method="addCss"> <stylesheet>css/styles.css</stylesheet> </action> <action method="addItem"> <type>skin_css</type> <name>css/iestyles.css</name> <params/> <if>IE</if> </action> <action method="addItem"> <type>skin_css</type> <name>css/ie7.css</name> <params/> <if>IE 7</if> </action> <action method="addItem"> <type>skin_css</type> <name>css/ie7minus.css</name> <params/> <if>lt IE 7</if> </action> <action method="addItem"> <type>js</type> <name>lib/ds-sleight.js</name> <params/> <if>lt IE 7</if> </action> <action method="addItem"> <type>js</type> <name>varien/iehover-fix.js</name> <params/> <if>lt IE 7</if> </action> <action method="addCss"> <stylesheet>css/print.css</stylesheet> <params>media="print"</params> </action> </block> <block type="page/html_header" name="header" as="header"> <block type="page/template_links" name="top.links" as="topLinks"/> <block type="page/switch" name="store_language" as="store_language" template="page/switch/languages.phtml"/> <block type="core/template" name="top.nav" template="page/html/top.nav.phtml"/> </block> <block type="core/messages" name="global_messages" as="global_messages"/> <block type="core/messages" name="messages" as="messages"/> <block type="core/text_list" name="content" as="content"/> <block type="core/text_list" name="right" as="right"/> <block type="page/html_footer" name="footer" as="footer" template="page/html/footer.phtml"/> <block type="core/text_list" name="before_body_end" as="before_body_end"/> </block> <block type="core/profiler" output="toHtml"/> <reference name="top.links"> <action method="addLink" translate="label title" module="customer"> <label>My Account</label> <url helper="customer/getAccountUrl"/> <title>My Account</title> <prepare/> <urlParams/> <position>10</position> </action> </reference> <reference name="root"> <action method="setTemplate"> <template>page/2columns-left.phtml</template> </action> </reference> <reference name="top.menu"> <block type="catalog/navigation" name="catalog.topnav" template="catalog/navigation/top.phtml"/> </reference> <reference name="footer_links"> <action method="addLink" translate="label title" module="catalog" ifconfig="catalog/seo/site_map"> <label>Site Map</label> <url helper="catalog/map/getCategoryUrl"/> <title>Site Map</title> </action> </reference> <reference name="footer_links"> <action method="addLink" translate="label title" module="catalogsearch" ifconfig="catalog/seo/search_terms"> <label>Search Terms</label> <url helper="catalogsearch/getSearchTermUrl"/> <title>Search Terms</title> </action> <action method="addLink" translate="label title" module="catalogsearch"> <label>Advanced Search</label> <url helper="catalogsearch/getAdvancedSearchUrl"/> <title>Advanced Search</title> </action> </reference> <reference name="top.links"> <block type="checkout/links" name="checkout_cart_link"> <action method="addCartLink"/> <action method="addCheckoutLink"/> </block> </reference> <reference name="footer"> <block type="cms/block" name="cms_footer_links" before="footer_links"> <action method="setBlockId"> <block_id>footer_links</block_id> </action> </block> </reference> <reference name="left"> <block type="tag/popular" name="tags_popular" template="tag/popular.phtm" ignore="1"> <action method="setTemplate"> <template>tag/popular.phtml</template> </action> </block> </reference> <reference name="left"> </reference> <reference name="before_body_end"> <block type="googleanalytics/ga" name="google_analytics" as="google_analytics"/> </reference> <reference name="footer_links"> <action method="addLink" translate="label title" module="contacts" ifconfig="contacts/contacts/enabled"> <label>Contact Us</label> <url>contact-us</url> <title>Contact Us</title> <prepare>true</prepare> </action> </reference> <reference name="footer_links"> <action method="addLink" translate="label title" module="rss" ifconfig="rss/config/active"> <label>RSS</label> <url>rss</url> <title>RSS testing</title> <prepare>true</prepare> <urlParams/> <position/> <li/> <a>class="link-feed"</a> </action> </reference> <reference name="wishlist_sidebar"> <action method="addPriceBlockType"> <type>bundle</type> <block>bundle/catalog_product_price</block> <template>bundle/catalog/product/price.phtml</template> </action> </reference> <reference name="cart_sidebar"> <action method="addItemRender"> <type>bundle</type> <block>bundle/checkout_cart_item_renderer</block> <template>checkout/cart/sidebar/default.phtml</template> </action> </reference> <reference name="root"> <action method="setTemplate"> <template>page/2columns-left.phtml</template> </action> </reference> <reference name="left"> <action method="unsetChild"> <name>catalog.navigation.all</name> </action> <action method="unsetChild"> <name>callout.sendcard</name> </action> <action method="unsetChild"> <name>callout.specialorder</name> </action> <block type="customer/account_navigation" name="customer_account_navigation" before="-" template="customer/account/navigation.phtml"> <action method="addLink" translate="label" module="customer"> <name>account</name> <path>customer/account/</path> <label>Account Dashboard</label> </action> <action method="addLink" translate="label" module="customer"> <name>account_edit</name> <path>customer/account/edit/</path> <label>Account Information</label> </action> <action method="addLink" translate="label" module="customer"> <name>address_book</name> <path>customer/address/</path> <label>Address Book</label> </action> </block> <block type="sales/reorder_sidebar" name="sale.reorder.sidebar" as="reorder" template="sales/reorder/sidebar.phtml"/> <remove name="tags_popular"/> </reference> <reference name="customer_account_navigation"> <action method="addLink" translate="label" module="sales"> <name>orders</name> <path>sales/order/history/</path> <label>My Orders</label> </action> </reference> <reference name="customer_account_navigation"> <action method="addLink" translate="label" module="tag"> <name>tags</name> <path>tag/customer/</path> <label>My Tags</label> </action> </reference> <reference name="customer_account_navigation"> <action method="addLink" translate="label" module="newsletter"> <name>newsletter</name> <path>newsletter/manage/</path> <label>Newsletter Subscriptions</label> </action> </reference> <reference name="cart_sidebar"> <action method="addItemRender"> <type>bundle</type> <block>bundle/checkout_cart_item_renderer</block> <template>checkout/cart/sidebar/default.phtml</template> </action> </reference> <update handle="customer_account"/> <reference name="content"> <block type="customer/account_dashboard" name="customer_account_dashboard" template="customer/account/dashboard.phtml"> <block type="customer/account_dashboard_hello" name="customer_account_dashboard_hello" as="hello" template="customer/account/dashboard/hello.phtml"/> <block type="core/template" name="customer_account_dashboard_top" as="top"/> <block type="customer/account_dashboard_info" name="customer_account_dashboard_info" as="info" template="customer/account/dashboard/info.phtml"/> <block type="customer/account_dashboard_newsletter" name="customer_account_dashboard_newsletter" as="newsletter" template="customer/account/dashboard/newsletter.phtml"/> <block type="customer/account_dashboard_address" name="customer_account_dashboard_address" as="address" template="customer/account/dashboard/address.phtml"/> <block type="core/template" name="customer_account_dashboard_info1" as="info1"/> <block type="core/template" name="customer_account_dashboard_info2" as="info2"/> </block> </reference> <reference name="right"> <action method="unsetChild"> <name>catalog_compare_sidebar</name> </action> </reference> <reference name="customer_account_dashboard"> <action method="unsetChild"> <name>top</name> </action> <block type="sales/order_recent" name="customer_account_dashboard_top" as="top" template="sales/order/recent.phtml"/> </reference> <reference name="right"> <action method="unsetChild"> <name>right.poll</name> </action> </reference> <reference name="customer_account_dashboard"> <action method="unsetChild"> <name>customer_account_dashboard_info2</name> </action> <block type="tag/customer_recent" name="customer_account_dashboard_info2" as="info2" template="tag/customer/recent.phtml"/> </reference> <reference name="right"> <action method="unsetChild"> <name>right.newsletter</name> </action> </reference> <reference name="top.links"> <action method="addLink" translate="label title" module="customer"> <label>Log Out</label> <url helper="customer/getLogoutUrl"/> <title>Log Out</title> <prepare/> <urlParams/> <position>100</position> </action> </reference></layout>

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  • Dynamic Types and DynamicObject References in C#

    - by Rick Strahl
    I've been working a bit with C# custom dynamic types for several customers recently and I've seen some confusion in understanding how dynamic types are referenced. This discussion specifically centers around types that implement IDynamicMetaObjectProvider or subclass from DynamicObject as opposed to arbitrary type casts of standard .NET types. IDynamicMetaObjectProvider types  are treated special when they are cast to the dynamic type. Assume for a second that I've created my own implementation of a custom dynamic type called DynamicFoo which is about as simple of a dynamic class that I can think of:public class DynamicFoo : DynamicObject { Dictionary<string, object> properties = new Dictionary<string, object>(); public string Bar { get; set; } public DateTime Entered { get; set; } public override bool TryGetMember(GetMemberBinder binder, out object result) { result = null; if (!properties.ContainsKey(binder.Name)) return false; result = properties[binder.Name]; return true; } public override bool TrySetMember(SetMemberBinder binder, object value) { properties[binder.Name] = value; return true; } } This class has an internal dictionary member and I'm exposing this dictionary member through a dynamic by implementing DynamicObject. This implementation exposes the properties dictionary so the dictionary keys can be referenced like properties (foo.NewProperty = "Cool!"). I override TryGetMember() and TrySetMember() which are fired at runtime every time you access a 'property' on a dynamic instance of this DynamicFoo type. Strong Typing and Dynamic Casting I now can instantiate and use DynamicFoo in a couple of different ways: Strong TypingDynamicFoo fooExplicit = new DynamicFoo(); var fooVar = new DynamicFoo(); These two commands are essentially identical and use strong typing. The compiler generates identical code for both of them. The var statement is merely a compiler directive to infer the type of fooVar at compile time and so the type of fooExplicit is DynamicFoo, just like fooExplicit. This is very static - nothing dynamic about it - and it completely ignores the IDynamicMetaObjectProvider implementation of my class above as it's never used. Using either of these I can access the native properties:DynamicFoo fooExplicit = new DynamicFoo();// static typing assignmentsfooVar.Bar = "Barred!"; fooExplicit.Entered = DateTime.Now; // echo back static values Console.WriteLine(fooVar.Bar); Console.WriteLine(fooExplicit.Entered); but I have no access whatsoever to the properties dictionary. Basically this creates a strongly typed instance of the type with access only to the strongly typed interface. You get no dynamic behavior at all. The IDynamicMetaObjectProvider features don't kick in until you cast the type to dynamic. If I try to access a non-existing property on fooExplicit I get a compilation error that tells me that the property doesn't exist. Again, it's clearly and utterly non-dynamic. Dynamicdynamic fooDynamic = new DynamicFoo(); fooDynamic on the other hand is created as a dynamic type and it's a completely different beast. I can also create a dynamic by simply casting any type to dynamic like this:DynamicFoo fooExplicit = new DynamicFoo(); dynamic fooDynamic = fooExplicit; Note that dynamic typically doesn't require an explicit cast as the compiler automatically performs the cast so there's no need to use as dynamic. Dynamic functionality works at runtime and allows for the dynamic wrapper to look up and call members dynamically. A dynamic type will look for members to access or call in two places: Using the strongly typed members of the object Using theIDynamicMetaObjectProvider Interface methods to access members So rather than statically linking and calling a method or retrieving a property, the dynamic type looks up - at runtime  - where the value actually comes from. It's essentially late-binding which allows runtime determination what action to take when a member is accessed at runtime *if* the member you are accessing does not exist on the object. Class members are checked first before IDynamicMetaObjectProvider interface methods are kick in. All of the following works with the dynamic type:dynamic fooDynamic = new DynamicFoo(); // dynamic typing assignments fooDynamic.NewProperty = "Something new!"; fooDynamic.LastAccess = DateTime.Now; // dynamic assigning static properties fooDynamic.Bar = "dynamic barred"; fooDynamic.Entered = DateTime.Now; // echo back dynamic values Console.WriteLine(fooDynamic.NewProperty); Console.WriteLine(fooDynamic.LastAccess); Console.WriteLine(fooDynamic.Bar); Console.WriteLine(fooDynamic.Entered); The dynamic type can access the native class properties (Bar and Entered) and create and read new ones (NewProperty,LastAccess) all using a single type instance which is pretty cool. As you can see it's pretty easy to create an extensible type this way that can dynamically add members at runtime dynamically. The Alter Ego of IDynamicObject The key point here is that all three statements - explicit, var and dynamic - declare a new DynamicFoo(), but the dynamic declaration results in completely different behavior than the first two simply because the type has been cast to dynamic. Dynamic binding means that the type loses its typical strong typing, compile time features. You can see this easily in the Visual Studio code editor. As soon as you assign a value to a dynamic you lose Intellisense and you see which means there's no Intellisense and no compiler type checking on any members you apply to this instance. If you're new to the dynamic type it might seem really confusing that a single type can behave differently depending on how it is cast, but that's exactly what happens when you use a type that implements IDynamicMetaObjectProvider. Declare the type as its strong type name and you only get to access the native instance members of the type. Declare or cast it to dynamic and you get dynamic behavior which accesses native members plus it uses IDynamicMetaObjectProvider implementation to handle any missing member definitions by running custom code. You can easily cast objects back and forth between dynamic and the original type:dynamic fooDynamic = new DynamicFoo(); fooDynamic.NewProperty = "New Property Value"; DynamicFoo foo = fooDynamic; foo.Bar = "Barred"; Here the code starts out with a dynamic cast and a dynamic assignment. The code then casts back the value to the DynamicFoo. Notice that when casting from dynamic to DynamicFoo and back we typically do not have to specify the cast explicitly - the compiler can induce the type so I don't need to specify as dynamic or as DynamicFoo. Moral of the Story This easy interchange between dynamic and the underlying type is actually super useful, because it allows you to create extensible objects that can expose non-member data stores and expose them as an object interface. You can create an object that hosts a number of strongly typed properties and then cast the object to dynamic and add additional dynamic properties to the same type at runtime. You can easily switch back and forth between the strongly typed instance to access the well-known strongly typed properties and to dynamic for the dynamic properties added at runtime. Keep in mind that dynamic object access has quite a bit of overhead and is definitely slower than strongly typed binding, so if you're accessing the strongly typed parts of your objects you definitely want to use a strongly typed reference. Reserve dynamic for the dynamic members to optimize your code. The real beauty of dynamic is that with very little effort you can build expandable objects or objects that expose different data stores to an object interface. I'll have more on this in my next post when I create a customized and extensible Expando object based on DynamicObject.© Rick Strahl, West Wind Technologies, 2005-2012Posted in CSharp  .NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • WCF – interchangeable data-contract types

    - by nmarun
    In a WSDL based environment, unlike a CLR-world, we pass around the ‘state’ of an object and not the reference of an object. Well firstly, what does ‘state’ mean and does this also mean that we can send a struct where a class is expected (or vice-versa) as long as their ‘state’ is one and the same? Let’s see. So I have an operation contract defined as below: 1: [ServiceContract] 2: public interface ILearnWcfServiceExtend : ILearnWcfService 3: { 4: [OperationContract] 5: Employee SaveEmployee(Employee employee); 6: } 7:  8: [ServiceBehavior] 9: public class LearnWcfService : ILearnWcfServiceExtend 10: { 11: public Employee SaveEmployee(Employee employee) 12: { 13: employee.EmployeeId = 123; 14: return employee; 15: } 16: } Quite simplistic operation there (which translates to ‘absolutely no business value’). Now, the data contract Employee mentioned above is a struct. 1: public struct Employee 2: { 3: public int EmployeeId { get; set; } 4:  5: public string FName { get; set; } 6: } After compilation and consumption of this service, my proxy (in the Reference.cs file) looks like below (I’ve ignored the rest of the details just to avoid unwanted confusion): 1: public partial struct Employee : System.Runtime.Serialization.IExtensibleDataObject, System.ComponentModel.INotifyPropertyChanged I call the service with the code below: 1: private static void CallWcfService() 2: { 3: Employee employee = new Employee { FName = "A" }; 4: Console.WriteLine("IsValueType: {0}", employee.GetType().IsValueType); 5: Console.WriteLine("IsClass: {0}", employee.GetType().IsClass); 6: Console.WriteLine("Before calling the service: {0} - {1}", employee.EmployeeId, employee.FName); 7: employee = LearnWcfServiceClient.SaveEmployee(employee); 8: Console.WriteLine("Return from the service: {0} - {1}", employee.EmployeeId, employee.FName); 9: } The output is: I now change my Employee type from a struct to a class in the proxy class and run the application: 1: public partial class Employee : System.Runtime.Serialization.IExtensibleDataObject, System.ComponentModel.INotifyPropertyChanged { The output this time is: The state of an object implies towards its composition, the properties and the values of these properties and not based on whether it is a reference type (class) or a value type (struct). And as shown above, we’re actually passing an object by its state and not by reference. Continuing on the same topic of ‘type-interchangeability’, WCF treats two data contracts as equivalent if they have the same ‘wire-representation’. We can do so using the DataContract and DataMember attributes’ Name property. 1: [DataContract] 2: public struct Person 3: { 4: [DataMember] 5: public int Id { get; set; } 6:  7: [DataMember] 8: public string FirstName { get; set; } 9: } 10:  11: [DataContract(Name="Person")] 12: public class Employee 13: { 14: [DataMember(Name = "Id")] 15: public int EmployeeId { get; set; } 16:  17: [DataMember(Name="FirstName")] 18: public string FName { get; set; } 19: } I’ve created two data contracts with the exact same wire-representation. Just remember that the names and the types of data members need to match to be considered equivalent. The question then arises as to what gets generated in the proxy class. Despite us declaring two data contracts (Person and Employee), only one gets emitted – Person. This is because we’re saying that the Employee type has the same wire-representation as the Person type. Also that the signature of the SaveEmployee operation gets changed on the proxy side: 1: [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "4.0.0.0")] 2: [System.ServiceModel.ServiceContractAttribute(ConfigurationName="ServiceProxy.ILearnWcfServiceExtend")] 3: public interface ILearnWcfServiceExtend 4: { 5: [System.ServiceModel.OperationContractAttribute(Action="http://tempuri.org/ILearnWcfServiceExtend/SaveEmployee", ReplyAction="http://tempuri.org/ILearnWcfServiceExtend/SaveEmployeeResponse")] 6: ClientApplication.ServiceProxy.Person SaveEmployee(ClientApplication.ServiceProxy.Person employee); 7: } But, on the service side, the SaveEmployee still accepts and returns an Employee data contract. 1: [ServiceBehavior] 2: public class LearnWcfService : ILearnWcfServiceExtend 3: { 4: public Employee SaveEmployee(Employee employee) 5: { 6: employee.EmployeeId = 123; 7: return employee; 8: } 9: } Despite all these changes, our output remains the same as the last one: This is type-interchangeability at work! Here’s one more thing to ponder about. Our Person type is a struct and Employee type is a class. Then how is it that the Person type got emitted as a ‘class’ in the proxy? It’s worth mentioning that WSDL describes a type called Employee and does not say whether it is a class or a struct (see the SOAP message below): 1: <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" 2: xmlns:tem="http://tempuri.org/" 3: xmlns:ser="http://schemas.datacontract.org/2004/07/ServiceApplication"> 4: <soapenv:Header/> 5: <soapenv:Body> 6: <tem:SaveEmployee> 7: <!--Optional:--> 8: <tem:employee> 9: <!--Optional:--> 10: <ser:EmployeeId>?</ser:EmployeeId> 11: <!--Optional:--> 12: <ser:FName>?</ser:FName> 13: </tem:employee> 14: </tem:SaveEmployee> 15: </soapenv:Body> 16: </soapenv:Envelope> There are some differences between how ‘Add Service Reference’ and the svcutil.exe generate the proxy class, but turns out both do some kind of reflection and determine the type of the data contract and emit the code accordingly. So since the Employee type is a class, the proxy ‘Person’ type gets generated as a class. In fact, reflecting on svcutil.exe application, you’ll see that there are a couple of places wherein a flag actually determines a type as a class or a struct. One example is in the ExportISerializableDataContract method in the System.Runtime.Serialization.CodeExporter class. Seems like these flags have a say in deciding whether the type gets emitted as a struct or a class. This behavior is different if you use the WSDL tool though. WSDL tool does not do any kind of reflection of the data contract / serialized type, it emits the type as a class by default. You can check this using the two command lines below:   Note to self: Remember ‘state’ and type-interchangeability when traversing through the WSDL planet!

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