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  • rails restful select_tag with :on_change

    - by Sam
    So I'm finally starting to use rest in rails. I want to have a select_tag with product categories and when one of the categories is selected I want it to update the products on change. I did this before with <% form_for :category, :url => { :action => "show" } do |f| %> <%= select_tag :id, options_from_collection_for_select(Category.find(:all), :id, :name), { :onchange => "this.form.submit();"} %> <% end %> however now it doesn't work because it tries to do the show action. I have two controllers 1) products 2) product_categories products belongs_to product_categories with a has_many How should I do this. Since the products are listed on the products controller and index action should I use the products controller or should I use the product_categories controller to find the category such as in the show action and then render the product/index page. But the real problem I have is how to get this form or any other option to work with restful routes.

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  • How to distinguish between the first and rest for duplicate records using sql ?

    - by Biswanath
    Hi, These are the input table and required output table. Input table ID Name ------------- 1 aaa 1 ababaa 2 bbbbbb 2 bcbcbccbc 2 bcdbcdbbbbb 3 ccccc Output table ID Name Ord ----------------------------- 1 aaa first 1 ababaa rest 2 bbbbbb first 2 bcbcbccbc rest 2 bcdbcdbbbbb rest 3 ccccc first First and Rest is based on the occurrence of an ID field. Is there a way to write a SQL query to achieve this ? P.S. - This question is somewhat similar to what I am looking for.

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  • OpenWorld 2012 : l'architecture multi-tenant au coeur d'Oracle 12c, une version résolument tournée vers le Cloud du célèbre SGBD

    OpenWorld 2012 : l'architecture multi-tenant au coeur d'Oracle 12c Une version résolument tournée vers le Cloud du célèbre SGBD d'entreprise Un C pour le Cloud qui sera au coeur de la prochaine version « 12c » du célèbre système de gestion de base de données d'Oracle. [IMG]http://idelways.developpez.com/news/images/cloud.jpg[/IMG] L'entreprise a annoncé une nouvelle version de son SGBD sous une approche « Multi-Tenant ». Larry Ellison a dévoilé à la conférence OpenWorld le serveur de base de données Oracle 12c, muni d'une nouvelle architecture « Multi-Tenant », basée sur le Cloud et qui sera disponible dès 2013. D'après le célèbre PDG, cette version prom...

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  • WebLogic Server Weekly for March 26th, 2012: WLS 1211 Update, Java 7 Certification, Galleria, WebLogic for DBAs, REST and Enterprise Architecture, Singleton Services

    - by Steve Button
    WebLogic Server 12c Certified with Java 7 for Production Use WebLogic Server 12c (12.1.1) has been certified with JDK 7 for development usage since December and we have now completed JDK 7 certification for use with production systems. In doing so, we have updated the WebLogic Server 12c (12.1.1) distributions incorporating fixes associated with JDK 7 support as well as some bundled patches that address several issues that have been discovered since the initial release. These updated distributions are available for download from OTN and will be beneficial for all WebLogic Server 12c (12.1.1) users in general. What's New Release Notes Download Here! Updated Oracle WebLogic Server 12.1.1.0 distribution Never one to miss a trick, Markus Eisele was one of the first to notice the WebLogic Server 12c update and post a blog about it. Sources told me that as of Friday last week you have an updated version of WebLogic Server 12c on OTN. http://blog.eisele.net/2012/03/updated-oracle-weblogic-server-12110.html Using WebLogic Server 12c with Java 7 - Video To illustrate the use of Java 7 with WebLogic Server 12c, I put together a screen cam showing the creation of a domain using Java 7 and then build and deploy a simple web application that uses Java 7 syntax to show it working. Ireland OUG Presentation: WebLogic for DBAs Simon Haslam posted his slides from a presentation he gave Dublin on 21/3/12 at the OUG Ireland conference. In this presentation, he explains the core concepts and ideas behind WebLogic Server, walks through an installation and offers some tips and common gotcha's to avoid. Simon also covers some aspects of installing and use Enterprise Manager 12c. Note: I usually install the JVM and use the generic .jar installer rather than using an installer bundled with a JVM. http://www.slideshare.net/Veriton/weblogic-for-dbas-10h Slightly Retro: Jeff West on Enterprise Architecure and REST In this weeks flashback, we look at Jeff West's blog from early 2011 where he provides some thoughtful opinions on enterprise architecture and innovation, then jumps into his views on REST. After I progressed in my career and did more team-leading and architecture type roles I was ‘educated’ on what it meant to have Asynchronous and Long-Running processes as part of your Enterprise Application architecture. If I had a synchronous process then I needed a thread available to service the request and then provide the response. https://blogs.oracle.com/jeffwest/entry/weblogic_integration_wli_web_services_and_soap_and_rest_part_1 Starting Managed Servers without an Administration Server using Node Manager and WLST Blogger weblogic-tips shows how to start a managed server without going through the Administration Server, using the Node Manager and WLST. Connect WLST to a Node Manager by entering the nmConnect command. http://www.weblogic-tips.com/2012/02/18/starting-managed-servers-without-an-administration-server-using-node-manager-and-wlst/ Using WebLogic Server Singleton Services WebLogic Server has supported the notion of a Singleton Service for a number of releases, in which WebLogic Server will maintain a single instance of a configured singleton service on one managed server within a cluster. This blog demonstrates how the singleton service can be accessed and used from applications deployed on the cluster. http://buttso.blogspot.com.au/2012/03/weblogic-server-singleton-services.html

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  • What should be included in risk management section of software's architecture documentation?

    - by Limbo Exile
    I am going to develop a Java application (a Spring Web application that will be used to extract data from various data sources) and I want to include risk management of the software in the architecture documentation. By risk management (I am not sure if this is the right name) I mean documenting possibilities of what can go wrong with the software and what to do in those cases. At first I tried to draft some lists, including things like database performance decrease, change of external components that the software interacts with, security breaches etc. But as I am not an experienced developer I cannot rely on those drafts, I don't think they are exhaustive. I searched web hoping to find something similar to the Joel Test or to find any other resource that will cite the most popular causes of problems that should be included and analyzed in risk management documentation, but I haven't found much. Finally, my question is: What should be included in risk management section of software's architecture documentation?

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  • Ubuntu One API Java - how to use REST and AccessToken?

    - by Michael
    I am writing a java app in eclipse that backups data to several consumer-cloud-services encrypted and redundant. So far, I successfully implemented the authentication process, as it is described in the documentation. At this point, I do not know how to proceed. The next step would be implementing the auth with the stored AccessToken and afterwars implementing upload/download/listing functionality through the REST API. I think I have to store the String oauth.getSerialized(). How do I authenticate with this String afterwards? This does not work e.g.: AuthenticateResponse oauth = api.authenticate(serialized); api.setAuthorizer(new OAuthAuthorizer(oauth)); Can someone tell me please, how I can use the REST API with java? There is no explanation or link in the developers area as far as I saw. And btw, I wasted at least one hour trying to fix errors, because some needed libraries are listet after the example code. :/

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  • Organization &amp; Architecture UNISA Studies &ndash; Chap 13

    - by MarkPearl
    Learning Outcomes Explain the advantages of using a large number of registers Discuss the way in which compilers optimize register usage Discuss the evolution of CISC machines Describe the characteristics of RISC architecture Discuss the RISC vs. CISC controversy Describe the way in which RISC and CISC design principles can be combined Instruction Execution Characteristics To understand the the line of reasoning of RISC advocates, we need a brief overview of instruction execution characteristics. These include… Operations Operands Procedure Calls These three sections can be studied in depth in the textbook at pages 503 - 505 A number of groups have come up with the conclusion that the attempt to make the instruction set architecture closer to HLLs (High Level Languages) is not the most effective design strategy. Rather HLL’s can be best supported by optimizing performance of the most time-consuming features of typical HLL programs. Generally 3 main characteristics came up to improve performance… Use a large number of registers or use a compiler to optimize register usage Careful attention needs to be paid to the design of instruction pipelines A simplified (reduced) instruction set is indicated The use of a large register optimization One of the most important design principles of RISC machines is the use of a large number of registers. The concept of register windows and the use of a large register file versus the use of cache memory are discussed. On the face of it, the use of a large set of registers should decrease the need to access memory. The design task is to organize the registers in such a fashion that this goal is realized. Read page 507 – 510 for a detailed explanation. Compiler-based register optimization   Reduced Instructions Set Architecture There are two advantages to smaller programs… Because the program takes up less memory, there is a savings in that resource (this was more compelling when memory was more expensive) Smaller programs should improve performance, and this will happen in two ways – fewer instructions means fewer instruction bytes to be fetched and in a paging environment smaller programs occupy fewer pages, reducing page faults. Certain characteristics are common to RISC processors… One instruction per cycle Register-to-register operations Simple addressing modes Simple instruction formats RISC vs. CISC After initial enthusiasm for RISC machines, there has been a growing realization that RISC designs may benefit from the inclusion of some CISC features CISC designs may benefit from the inclusion of some RISC features

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  • Choices in Architecture, Design, Algorithms, Data Structures for effective RDF Reasoning and Querying in a Big Data Environment [on hold]

    - by user2891213
    As part of my academic project I would like to know what choices in Architecture, Design, Algorithms, Data Structures do we need in order to provide effective and efficient RDF Reasoning and Querying in a Big Data Environment. Basically I want to get info regarding below points: What are the Systems and Software to get appropriate Architecture? What kind of API layer(s) would we need on top of the Big Data stores, to make this possible? The Indexing structures we will need. The appropriate Algorithms, and appropriate Algorithms for Query Planning across Big Data stores. The Performance Analysis and Cost Models we will need to justify the design decisions we have made along the way. Can anyone please provide pointers.. Thanks, David

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  • Sortie de Redmine 1.1.0, le gestionnaire de projet basé sur Ruby on Rails propose une API REST totalement remise à neuf

    Sortie de Redmine 1.1.0 Le gestionnaire de projet basé sur Ruby on Rails propose une API REST totalement remise à neuf Redmine 1.1.0 vient de sortir. Au contraire de la première version de la branche 1.0, cette version n'est pas qualifiée de release candidate (RC). Cette version a vu quelques projets d'ampleur se réaliser. Citons notamment la réécriture du Gantt. Mais surtout : une API REST totalement remise à neuf. La nouvelle implémentation se rapproche des standards du framework Rails, rendant plus aisé l'ajout de nouvelles API. Elle se targue aussi d'être plus complète en ce qui concerne les projets et les dema...

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  • ExpressionEngine 2 module "tag cannot be processed"

    - by Phil Sturgeon
    So I have turned my hand to ExpressionEngine and while the backend crud was easy enough getting the frontend working with template syntax is proving difficult, even at the "hello world" level. expressionengine/third_party/rest/mod.rest.php class Rest { var $return_data = ''; function Rest() { $this->EE =& get_instance(); return $this->return_data = 'HAI'; } } // END REST Class /* End of file REST.php */ /* Location: ./application/libraries/REST.php */ Then im calling it directly in a new empty template: {exp:rest} So I'm expecting to see "HAI" but I get: Error The following tag cannot be processed: {exp:rest} Please check that the ‘rest’ module is installed and that ‘rest’ is an available method of the module Any ideas? The module is installed and the backend is running fine.

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  • Introduction to the ASP.NET Web API

    - by Stephen.Walther
    I am a huge fan of Ajax. If you want to create a great experience for the users of your website – regardless of whether you are building an ASP.NET MVC or an ASP.NET Web Forms site — then you need to use Ajax. Otherwise, you are just being cruel to your customers. We use Ajax extensively in several of the ASP.NET applications that my company, Superexpert.com, builds. We expose data from the server as JSON and use jQuery to retrieve and update that data from the browser. One challenge, when building an ASP.NET website, is deciding on which technology to use to expose JSON data from the server. For example, how do you expose a list of products from the server as JSON so you can retrieve the list of products with jQuery? You have a number of options (too many options) including ASMX Web services, WCF Web Services, ASHX Generic Handlers, WCF Data Services, and MVC controller actions. Fortunately, the world has just been simplified. With the release of ASP.NET 4 Beta, Microsoft has introduced a new technology for exposing JSON from the server named the ASP.NET Web API. You can use the ASP.NET Web API with both ASP.NET MVC and ASP.NET Web Forms applications. The goal of this blog post is to provide you with a brief overview of the features of the new ASP.NET Web API. You learn how to use the ASP.NET Web API to retrieve, insert, update, and delete database records with jQuery. We also discuss how you can perform form validation when using the Web API and use OData when using the Web API. Creating an ASP.NET Web API Controller The ASP.NET Web API exposes JSON data through a new type of controller called an API controller. You can add an API controller to an existing ASP.NET MVC 4 project through the standard Add Controller dialog box. Right-click your Controllers folder and select Add, Controller. In the dialog box, name your controller MovieController and select the Empty API controller template: A brand new API controller looks like this: using System; using System.Collections.Generic; using System.Linq; using System.Net.Http; using System.Web.Http; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { } } An API controller, unlike a standard MVC controller, derives from the base ApiController class instead of the base Controller class. Using jQuery to Retrieve, Insert, Update, and Delete Data Let’s create an Ajaxified Movie Database application. We’ll retrieve, insert, update, and delete movies using jQuery with the MovieController which we just created. Our Movie model class looks like this: namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } public string Title { get; set; } public string Director { get; set; } } } Our application will consist of a single HTML page named Movies.html. We’ll place all of our jQuery code in the Movies.html page. Getting a Single Record with the ASP.NET Web API To support retrieving a single movie from the server, we need to add a Get method to our API controller: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public Movie GetMovie(int id) { // Return movie by id if (id == 1) { return new Movie { Id = 1, Title = "Star Wars", Director = "Lucas" }; } // Otherwise, movie was not found throw new HttpResponseException(HttpStatusCode.NotFound); } } } In the code above, the GetMovie() method accepts the Id of a movie. If the Id has the value 1 then the method returns the movie Star Wars. Otherwise, the method throws an exception and returns 404 Not Found HTTP status code. After building your project, you can invoke the MovieController.GetMovie() method by entering the following URL in your web browser address bar: http://localhost:[port]/api/movie/1 (You’ll need to enter the correct randomly generated port). In the URL api/movie/1, the first “api” segment indicates that this is a Web API route. The “movie” segment indicates that the MovieController should be invoked. You do not specify the name of the action. Instead, the HTTP method used to make the request – GET, POST, PUT, DELETE — is used to identify the action to invoke. The ASP.NET Web API uses different routing conventions than normal ASP.NET MVC controllers. When you make an HTTP GET request then any API controller method with a name that starts with “GET” is invoked. So, we could have called our API controller action GetPopcorn() instead of GetMovie() and it would still be invoked by the URL api/movie/1. The default route for the Web API is defined in the Global.asax file and it looks like this: routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); We can invoke our GetMovie() controller action with the jQuery code in the following HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Get Movie</title> </head> <body> <div> Title: <span id="title"></span> </div> <div> Director: <span id="director"></span> </div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> getMovie(1, function (movie) { $("#title").html(movie.Title); $("#director").html(movie.Director); }); function getMovie(id, callback) { $.ajax({ url: "/api/Movie", data: { id: id }, type: "GET", contentType: "application/json;charset=utf-8", statusCode: { 200: function (movie) { callback(movie); }, 404: function () { alert("Not Found!"); } } }); } </script> </body> </html> In the code above, the jQuery $.ajax() method is used to invoke the GetMovie() method. Notice that the Ajax call handles two HTTP response codes. When the GetMove() method successfully returns a movie, the method returns a 200 status code. In that case, the details of the movie are displayed in the HTML page. Otherwise, if the movie is not found, the GetMovie() method returns a 404 status code. In that case, the page simply displays an alert box indicating that the movie was not found (hopefully, you would implement something more graceful in an actual application). You can use your browser’s Developer Tools to see what is going on in the background when you open the HTML page (hit F12 in the most recent version of most browsers). For example, you can use the Network tab in Google Chrome to see the Ajax request which invokes the GetMovie() method: Getting a Set of Records with the ASP.NET Web API Let’s modify our Movie API controller so that it returns a collection of movies. The following Movie controller has a new ListMovies() method which returns a (hard-coded) collection of movies: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public IEnumerable<Movie> ListMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=1, Title="King Kong", Director="Jackson"}, new Movie {Id=1, Title="Memento", Director="Nolan"} }; } } } Because we named our action ListMovies(), the default Web API route will never match it. Therefore, we need to add the following custom route to our Global.asax file (at the top of the RegisterRoutes() method): routes.MapHttpRoute( name: "ActionApi", routeTemplate: "api/{controller}/{action}/{id}", defaults: new { id = RouteParameter.Optional } ); This route enables us to invoke the ListMovies() method with the URL /api/movie/listmovies. Now that we have exposed our collection of movies from the server, we can retrieve and display the list of movies using jQuery in our HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>List Movies</title> </head> <body> <div id="movies"></div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> listMovies(function (movies) { var strMovies=""; $.each(movies, function (index, movie) { strMovies += "<div>" + movie.Title + "</div>"; }); $("#movies").html(strMovies); }); function listMovies(callback) { $.ajax({ url: "/api/Movie/ListMovies", data: {}, type: "GET", contentType: "application/json;charset=utf-8", }).then(function(movies){ callback(movies); }); } </script> </body> </html>     Inserting a Record with the ASP.NET Web API Now let’s modify our Movie API controller so it supports creating new records: public HttpResponseMessage<Movie> PostMovie(Movie movieToCreate) { // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } The PostMovie() method in the code above accepts a movieToCreate parameter. We don’t actually store the new movie anywhere. In real life, you will want to call a service method to store the new movie in a database. When you create a new resource, such as a new movie, you should return the location of the new resource. In the code above, the URL where the new movie can be retrieved is assigned to the Location header returned in the PostMovie() response. Because the name of our method starts with “Post”, we don’t need to create a custom route. The PostMovie() method can be invoked with the URL /Movie/PostMovie – just as long as the method is invoked within the context of a HTTP POST request. The following HTML page invokes the PostMovie() method. <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "Jackson" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }); function createMovie(movieToCreate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); } </script> </body> </html> This page creates a new movie (the Hobbit) by calling the createMovie() method. The page simply displays the Id of the new movie: The HTTP Post operation is performed with the following call to the jQuery $.ajax() method: $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); Notice that the type of Ajax request is a POST request. This is required to match the PostMovie() method. Notice, furthermore, that the new movie is converted into JSON using JSON.stringify(). The JSON.stringify() method takes a JavaScript object and converts it into a JSON string. Finally, notice that success is represented with a 201 status code. The HttpStatusCode.Created value returned from the PostMovie() method returns a 201 status code. Updating a Record with the ASP.NET Web API Here’s how we can modify the Movie API controller to support updating an existing record. In this case, we need to create a PUT method to handle an HTTP PUT request: public void PutMovie(Movie movieToUpdate) { if (movieToUpdate.Id == 1) { // Update the movie in the database return; } // If you can't find the movie to update throw new HttpResponseException(HttpStatusCode.NotFound); } Unlike our PostMovie() method, the PutMovie() method does not return a result. The action either updates the database or, if the movie cannot be found, returns an HTTP Status code of 404. The following HTML page illustrates how you can invoke the PutMovie() method: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Put Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToUpdate = { id: 1, title: "The Hobbit", director: "Jackson" }; updateMovie(movieToUpdate, function () { alert("Movie updated!"); }); function updateMovie(movieToUpdate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToUpdate), type: "PUT", contentType: "application/json;charset=utf-8", statusCode: { 200: function () { callback(); }, 404: function () { alert("Movie not found!"); } } }); } </script> </body> </html> Deleting a Record with the ASP.NET Web API Here’s the code for deleting a movie: public HttpResponseMessage DeleteMovie(int id) { // Delete the movie from the database // Return status code return new HttpResponseMessage(HttpStatusCode.NoContent); } This method simply deletes the movie (well, not really, but pretend that it does) and returns a No Content status code (204). The following page illustrates how you can invoke the DeleteMovie() action: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Delete Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> deleteMovie(1, function () { alert("Movie deleted!"); }); function deleteMovie(id, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify({id:id}), type: "DELETE", contentType: "application/json;charset=utf-8", statusCode: { 204: function () { callback(); } } }); } </script> </body> </html> Performing Validation How do you perform form validation when using the ASP.NET Web API? Because validation in ASP.NET MVC is driven by the Default Model Binder, and because the Web API uses the Default Model Binder, you get validation for free. Let’s modify our Movie class so it includes some of the standard validation attributes: using System.ComponentModel.DataAnnotations; namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } [Required(ErrorMessage="Title is required!")] [StringLength(5, ErrorMessage="Title cannot be more than 5 characters!")] public string Title { get; set; } [Required(ErrorMessage="Director is required!")] public string Director { get; set; } } } In the code above, the Required validation attribute is used to make both the Title and Director properties required. The StringLength attribute is used to require the length of the movie title to be no more than 5 characters. Now let’s modify our PostMovie() action to validate a movie before adding the movie to the database: public HttpResponseMessage PostMovie(Movie movieToCreate) { // Validate movie if (!ModelState.IsValid) { var errors = new JsonArray(); foreach (var prop in ModelState.Values) { if (prop.Errors.Any()) { errors.Add(prop.Errors.First().ErrorMessage); } } return new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } If ModelState.IsValid has the value false then the errors in model state are copied to a new JSON array. Each property – such as the Title and Director property — can have multiple errors. In the code above, only the first error message is copied over. The JSON array is returned with a Bad Request status code (400 status code). The following HTML page illustrates how you can invoke our modified PostMovie() action and display any error messages: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }, function (errors) { var strErrors = ""; $.each(errors, function(index, err) { strErrors += "*" + err + "\n"; }); alert(strErrors); } ); function createMovie(movieToCreate, success, fail) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToCreate), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { success(newMovie); }, 400: function (xhr) { var errors = JSON.parse(xhr.responseText); fail(errors); } } }); } </script> </body> </html> The createMovie() function performs an Ajax request and handles either a 201 or a 400 status code from the response. If a 201 status code is returned then there were no validation errors and the new movie was created. If, on the other hand, a 400 status code is returned then there was a validation error. The validation errors are retrieved from the XmlHttpRequest responseText property. The error messages are displayed in an alert: (Please don’t use JavaScript alert dialogs to display validation errors, I just did it this way out of pure laziness) This validation code in our PostMovie() method is pretty generic. There is nothing specific about this code to the PostMovie() method. In the following video, Jon Galloway demonstrates how to create a global Validation filter which can be used with any API controller action: http://www.asp.net/web-api/overview/web-api-routing-and-actions/video-custom-validation His validation filter looks like this: using System.Json; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http.Controllers; using System.Web.Http.Filters; namespace MyWebAPIApp.Filters { public class ValidationActionFilter:ActionFilterAttribute { public override void OnActionExecuting(HttpActionContext actionContext) { var modelState = actionContext.ModelState; if (!modelState.IsValid) { dynamic errors = new JsonObject(); foreach (var key in modelState.Keys) { var state = modelState[key]; if (state.Errors.Any()) { errors[key] = state.Errors.First().ErrorMessage; } } actionContext.Response = new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } } } } And you can register the validation filter in the Application_Start() method in the Global.asax file like this: GlobalConfiguration.Configuration.Filters.Add(new ValidationActionFilter()); After you register the Validation filter, validation error messages are returned from any API controller action method automatically when validation fails. You don’t need to add any special logic to any of your API controller actions to take advantage of the filter. Querying using OData The OData protocol is an open protocol created by Microsoft which enables you to perform queries over the web. The official website for OData is located here: http://odata.org For example, here are some of the query options which you can use with OData: · $orderby – Enables you to retrieve results in a certain order. · $top – Enables you to retrieve a certain number of results. · $skip – Enables you to skip over a certain number of results (use with $top for paging). · $filter – Enables you to filter the results returned. The ASP.NET Web API supports a subset of the OData protocol. You can use all of the query options listed above when interacting with an API controller. The only requirement is that the API controller action returns its data as IQueryable. For example, the following Movie controller has an action named GetMovies() which returns an IQueryable of movies: public IQueryable<Movie> GetMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=2, Title="King Kong", Director="Jackson"}, new Movie {Id=3, Title="Willow", Director="Lucas"}, new Movie {Id=4, Title="Shrek", Director="Smith"}, new Movie {Id=5, Title="Memento", Director="Nolan"} }.AsQueryable(); } If you enter the following URL in your browser: /api/movie?$top=2&$orderby=Title Then you will limit the movies returned to the top 2 in order of the movie Title. You will get the following results: By using the $top option in combination with the $skip option, you can enable client-side paging. For example, you can use $top and $skip to page through thousands of products, 10 products at a time. The $filter query option is very powerful. You can use this option to filter the results from a query. Here are some examples: Return every movie directed by Lucas: /api/movie?$filter=Director eq ‘Lucas’ Return every movie which has a title which starts with ‘S’: /api/movie?$filter=startswith(Title,’S') Return every movie which has an Id greater than 2: /api/movie?$filter=Id gt 2 The complete documentation for the $filter option is located here: http://www.odata.org/developers/protocols/uri-conventions#FilterSystemQueryOption Summary The goal of this blog entry was to provide you with an overview of the new ASP.NET Web API introduced with the Beta release of ASP.NET 4. In this post, I discussed how you can retrieve, insert, update, and delete data by using jQuery with the Web API. I also discussed how you can use the standard validation attributes with the Web API. You learned how to return validation error messages to the client and display the error messages using jQuery. Finally, we briefly discussed how the ASP.NET Web API supports the OData protocol. For example, you learned how to filter records returned from an API controller action by using the $filter query option. I’m excited about the new Web API. This is a feature which I expect to use with almost every ASP.NET application which I build in the future.

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  • Introduction to the ASP.NET Web API

    - by Stephen.Walther
    I am a huge fan of Ajax. If you want to create a great experience for the users of your website – regardless of whether you are building an ASP.NET MVC or an ASP.NET Web Forms site — then you need to use Ajax. Otherwise, you are just being cruel to your customers. We use Ajax extensively in several of the ASP.NET applications that my company, Superexpert.com, builds. We expose data from the server as JSON and use jQuery to retrieve and update that data from the browser. One challenge, when building an ASP.NET website, is deciding on which technology to use to expose JSON data from the server. For example, how do you expose a list of products from the server as JSON so you can retrieve the list of products with jQuery? You have a number of options (too many options) including ASMX Web services, WCF Web Services, ASHX Generic Handlers, WCF Data Services, and MVC controller actions. Fortunately, the world has just been simplified. With the release of ASP.NET 4 Beta, Microsoft has introduced a new technology for exposing JSON from the server named the ASP.NET Web API. You can use the ASP.NET Web API with both ASP.NET MVC and ASP.NET Web Forms applications. The goal of this blog post is to provide you with a brief overview of the features of the new ASP.NET Web API. You learn how to use the ASP.NET Web API to retrieve, insert, update, and delete database records with jQuery. We also discuss how you can perform form validation when using the Web API and use OData when using the Web API. Creating an ASP.NET Web API Controller The ASP.NET Web API exposes JSON data through a new type of controller called an API controller. You can add an API controller to an existing ASP.NET MVC 4 project through the standard Add Controller dialog box. Right-click your Controllers folder and select Add, Controller. In the dialog box, name your controller MovieController and select the Empty API controller template: A brand new API controller looks like this: using System; using System.Collections.Generic; using System.Linq; using System.Net.Http; using System.Web.Http; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { } } An API controller, unlike a standard MVC controller, derives from the base ApiController class instead of the base Controller class. Using jQuery to Retrieve, Insert, Update, and Delete Data Let’s create an Ajaxified Movie Database application. We’ll retrieve, insert, update, and delete movies using jQuery with the MovieController which we just created. Our Movie model class looks like this: namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } public string Title { get; set; } public string Director { get; set; } } } Our application will consist of a single HTML page named Movies.html. We’ll place all of our jQuery code in the Movies.html page. Getting a Single Record with the ASP.NET Web API To support retrieving a single movie from the server, we need to add a Get method to our API controller: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public Movie GetMovie(int id) { // Return movie by id if (id == 1) { return new Movie { Id = 1, Title = "Star Wars", Director = "Lucas" }; } // Otherwise, movie was not found throw new HttpResponseException(HttpStatusCode.NotFound); } } } In the code above, the GetMovie() method accepts the Id of a movie. If the Id has the value 1 then the method returns the movie Star Wars. Otherwise, the method throws an exception and returns 404 Not Found HTTP status code. After building your project, you can invoke the MovieController.GetMovie() method by entering the following URL in your web browser address bar: http://localhost:[port]/api/movie/1 (You’ll need to enter the correct randomly generated port). In the URL api/movie/1, the first “api” segment indicates that this is a Web API route. The “movie” segment indicates that the MovieController should be invoked. You do not specify the name of the action. Instead, the HTTP method used to make the request – GET, POST, PUT, DELETE — is used to identify the action to invoke. The ASP.NET Web API uses different routing conventions than normal ASP.NET MVC controllers. When you make an HTTP GET request then any API controller method with a name that starts with “GET” is invoked. So, we could have called our API controller action GetPopcorn() instead of GetMovie() and it would still be invoked by the URL api/movie/1. The default route for the Web API is defined in the Global.asax file and it looks like this: routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); We can invoke our GetMovie() controller action with the jQuery code in the following HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Get Movie</title> </head> <body> <div> Title: <span id="title"></span> </div> <div> Director: <span id="director"></span> </div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> getMovie(1, function (movie) { $("#title").html(movie.Title); $("#director").html(movie.Director); }); function getMovie(id, callback) { $.ajax({ url: "/api/Movie", data: { id: id }, type: "GET", contentType: "application/json;charset=utf-8", statusCode: { 200: function (movie) { callback(movie); }, 404: function () { alert("Not Found!"); } } }); } </script> </body> </html> In the code above, the jQuery $.ajax() method is used to invoke the GetMovie() method. Notice that the Ajax call handles two HTTP response codes. When the GetMove() method successfully returns a movie, the method returns a 200 status code. In that case, the details of the movie are displayed in the HTML page. Otherwise, if the movie is not found, the GetMovie() method returns a 404 status code. In that case, the page simply displays an alert box indicating that the movie was not found (hopefully, you would implement something more graceful in an actual application). You can use your browser’s Developer Tools to see what is going on in the background when you open the HTML page (hit F12 in the most recent version of most browsers). For example, you can use the Network tab in Google Chrome to see the Ajax request which invokes the GetMovie() method: Getting a Set of Records with the ASP.NET Web API Let’s modify our Movie API controller so that it returns a collection of movies. The following Movie controller has a new ListMovies() method which returns a (hard-coded) collection of movies: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public IEnumerable<Movie> ListMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=1, Title="King Kong", Director="Jackson"}, new Movie {Id=1, Title="Memento", Director="Nolan"} }; } } } Because we named our action ListMovies(), the default Web API route will never match it. Therefore, we need to add the following custom route to our Global.asax file (at the top of the RegisterRoutes() method): routes.MapHttpRoute( name: "ActionApi", routeTemplate: "api/{controller}/{action}/{id}", defaults: new { id = RouteParameter.Optional } ); This route enables us to invoke the ListMovies() method with the URL /api/movie/listmovies. Now that we have exposed our collection of movies from the server, we can retrieve and display the list of movies using jQuery in our HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>List Movies</title> </head> <body> <div id="movies"></div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> listMovies(function (movies) { var strMovies=""; $.each(movies, function (index, movie) { strMovies += "<div>" + movie.Title + "</div>"; }); $("#movies").html(strMovies); }); function listMovies(callback) { $.ajax({ url: "/api/Movie/ListMovies", data: {}, type: "GET", contentType: "application/json;charset=utf-8", }).then(function(movies){ callback(movies); }); } </script> </body> </html>     Inserting a Record with the ASP.NET Web API Now let’s modify our Movie API controller so it supports creating new records: public HttpResponseMessage<Movie> PostMovie(Movie movieToCreate) { // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } The PostMovie() method in the code above accepts a movieToCreate parameter. We don’t actually store the new movie anywhere. In real life, you will want to call a service method to store the new movie in a database. When you create a new resource, such as a new movie, you should return the location of the new resource. In the code above, the URL where the new movie can be retrieved is assigned to the Location header returned in the PostMovie() response. Because the name of our method starts with “Post”, we don’t need to create a custom route. The PostMovie() method can be invoked with the URL /Movie/PostMovie – just as long as the method is invoked within the context of a HTTP POST request. The following HTML page invokes the PostMovie() method. <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "Jackson" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }); function createMovie(movieToCreate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); } </script> </body> </html> This page creates a new movie (the Hobbit) by calling the createMovie() method. The page simply displays the Id of the new movie: The HTTP Post operation is performed with the following call to the jQuery $.ajax() method: $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); Notice that the type of Ajax request is a POST request. This is required to match the PostMovie() method. Notice, furthermore, that the new movie is converted into JSON using JSON.stringify(). The JSON.stringify() method takes a JavaScript object and converts it into a JSON string. Finally, notice that success is represented with a 201 status code. The HttpStatusCode.Created value returned from the PostMovie() method returns a 201 status code. Updating a Record with the ASP.NET Web API Here’s how we can modify the Movie API controller to support updating an existing record. In this case, we need to create a PUT method to handle an HTTP PUT request: public void PutMovie(Movie movieToUpdate) { if (movieToUpdate.Id == 1) { // Update the movie in the database return; } // If you can't find the movie to update throw new HttpResponseException(HttpStatusCode.NotFound); } Unlike our PostMovie() method, the PutMovie() method does not return a result. The action either updates the database or, if the movie cannot be found, returns an HTTP Status code of 404. The following HTML page illustrates how you can invoke the PutMovie() method: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Put Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToUpdate = { id: 1, title: "The Hobbit", director: "Jackson" }; updateMovie(movieToUpdate, function () { alert("Movie updated!"); }); function updateMovie(movieToUpdate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToUpdate), type: "PUT", contentType: "application/json;charset=utf-8", statusCode: { 200: function () { callback(); }, 404: function () { alert("Movie not found!"); } } }); } </script> </body> </html> Deleting a Record with the ASP.NET Web API Here’s the code for deleting a movie: public HttpResponseMessage DeleteMovie(int id) { // Delete the movie from the database // Return status code return new HttpResponseMessage(HttpStatusCode.NoContent); } This method simply deletes the movie (well, not really, but pretend that it does) and returns a No Content status code (204). The following page illustrates how you can invoke the DeleteMovie() action: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Delete Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> deleteMovie(1, function () { alert("Movie deleted!"); }); function deleteMovie(id, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify({id:id}), type: "DELETE", contentType: "application/json;charset=utf-8", statusCode: { 204: function () { callback(); } } }); } </script> </body> </html> Performing Validation How do you perform form validation when using the ASP.NET Web API? Because validation in ASP.NET MVC is driven by the Default Model Binder, and because the Web API uses the Default Model Binder, you get validation for free. Let’s modify our Movie class so it includes some of the standard validation attributes: using System.ComponentModel.DataAnnotations; namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } [Required(ErrorMessage="Title is required!")] [StringLength(5, ErrorMessage="Title cannot be more than 5 characters!")] public string Title { get; set; } [Required(ErrorMessage="Director is required!")] public string Director { get; set; } } } In the code above, the Required validation attribute is used to make both the Title and Director properties required. The StringLength attribute is used to require the length of the movie title to be no more than 5 characters. Now let’s modify our PostMovie() action to validate a movie before adding the movie to the database: public HttpResponseMessage PostMovie(Movie movieToCreate) { // Validate movie if (!ModelState.IsValid) { var errors = new JsonArray(); foreach (var prop in ModelState.Values) { if (prop.Errors.Any()) { errors.Add(prop.Errors.First().ErrorMessage); } } return new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } If ModelState.IsValid has the value false then the errors in model state are copied to a new JSON array. Each property – such as the Title and Director property — can have multiple errors. In the code above, only the first error message is copied over. The JSON array is returned with a Bad Request status code (400 status code). The following HTML page illustrates how you can invoke our modified PostMovie() action and display any error messages: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }, function (errors) { var strErrors = ""; $.each(errors, function(index, err) { strErrors += "*" + err + "n"; }); alert(strErrors); } ); function createMovie(movieToCreate, success, fail) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToCreate), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { success(newMovie); }, 400: function (xhr) { var errors = JSON.parse(xhr.responseText); fail(errors); } } }); } </script> </body> </html> The createMovie() function performs an Ajax request and handles either a 201 or a 400 status code from the response. If a 201 status code is returned then there were no validation errors and the new movie was created. If, on the other hand, a 400 status code is returned then there was a validation error. The validation errors are retrieved from the XmlHttpRequest responseText property. The error messages are displayed in an alert: (Please don’t use JavaScript alert dialogs to display validation errors, I just did it this way out of pure laziness) This validation code in our PostMovie() method is pretty generic. There is nothing specific about this code to the PostMovie() method. In the following video, Jon Galloway demonstrates how to create a global Validation filter which can be used with any API controller action: http://www.asp.net/web-api/overview/web-api-routing-and-actions/video-custom-validation His validation filter looks like this: using System.Json; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http.Controllers; using System.Web.Http.Filters; namespace MyWebAPIApp.Filters { public class ValidationActionFilter:ActionFilterAttribute { public override void OnActionExecuting(HttpActionContext actionContext) { var modelState = actionContext.ModelState; if (!modelState.IsValid) { dynamic errors = new JsonObject(); foreach (var key in modelState.Keys) { var state = modelState[key]; if (state.Errors.Any()) { errors[key] = state.Errors.First().ErrorMessage; } } actionContext.Response = new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } } } } And you can register the validation filter in the Application_Start() method in the Global.asax file like this: GlobalConfiguration.Configuration.Filters.Add(new ValidationActionFilter()); After you register the Validation filter, validation error messages are returned from any API controller action method automatically when validation fails. You don’t need to add any special logic to any of your API controller actions to take advantage of the filter. Querying using OData The OData protocol is an open protocol created by Microsoft which enables you to perform queries over the web. The official website for OData is located here: http://odata.org For example, here are some of the query options which you can use with OData: · $orderby – Enables you to retrieve results in a certain order. · $top – Enables you to retrieve a certain number of results. · $skip – Enables you to skip over a certain number of results (use with $top for paging). · $filter – Enables you to filter the results returned. The ASP.NET Web API supports a subset of the OData protocol. You can use all of the query options listed above when interacting with an API controller. The only requirement is that the API controller action returns its data as IQueryable. For example, the following Movie controller has an action named GetMovies() which returns an IQueryable of movies: public IQueryable<Movie> GetMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=2, Title="King Kong", Director="Jackson"}, new Movie {Id=3, Title="Willow", Director="Lucas"}, new Movie {Id=4, Title="Shrek", Director="Smith"}, new Movie {Id=5, Title="Memento", Director="Nolan"} }.AsQueryable(); } If you enter the following URL in your browser: /api/movie?$top=2&$orderby=Title Then you will limit the movies returned to the top 2 in order of the movie Title. You will get the following results: By using the $top option in combination with the $skip option, you can enable client-side paging. For example, you can use $top and $skip to page through thousands of products, 10 products at a time. The $filter query option is very powerful. You can use this option to filter the results from a query. Here are some examples: Return every movie directed by Lucas: /api/movie?$filter=Director eq ‘Lucas’ Return every movie which has a title which starts with ‘S’: /api/movie?$filter=startswith(Title,’S') Return every movie which has an Id greater than 2: /api/movie?$filter=Id gt 2 The complete documentation for the $filter option is located here: http://www.odata.org/developers/protocols/uri-conventions#FilterSystemQueryOption Summary The goal of this blog entry was to provide you with an overview of the new ASP.NET Web API introduced with the Beta release of ASP.NET 4. In this post, I discussed how you can retrieve, insert, update, and delete data by using jQuery with the Web API. I also discussed how you can use the standard validation attributes with the Web API. You learned how to return validation error messages to the client and display the error messages using jQuery. Finally, we briefly discussed how the ASP.NET Web API supports the OData protocol. For example, you learned how to filter records returned from an API controller action by using the $filter query option. I’m excited about the new Web API. This is a feature which I expect to use with almost every ASP.NET application which I build in the future.

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  • Patterns for non-layered applications

    - by Paul Stovell
    In Patterns of Enterprise Application Architecture, Martin Fowler writes: This book is thus about how you decompose an enterprise application into layers and how those layers work together. Most nontrivial enterprise applications use a layered architecture of some form, but in some situations other approaches, such as pipes and filters, are valuable. I don't go into those situations, focussing instead on the context of a layered architecture because it's the most widely useful. What patterns exist for building non-layered applications/parts of an application? Take a statistical modelling engine for a financial institution. There might be a layer for data access, but I expect that most of the code would be in a single layer. Would you still expect to see Gang of Four patterns in such a layer? How about a domain model? Would you use OO at all, or would it be purely functional? The quote mentions pipes and filters as alternate models to layers. I can easily imagine a such an engine using pipes as a way to break down the data processing. What other patterns exist? Are there common patterns for areas like task scheduling, results aggregation, or work distribution? What are some alternatives to MapReduce?

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  • How to understand other people's CSS architectures?

    - by John
    I am reasonably good with CSS. However, when working with someone else's CSS, it's difficult for me to see the "bigger picture" in their architecture (but i have no problem when working with a CSS sheet I wrote myself). For example, I have no problems using Firebug to isolate and fix cross browser compatibility issues, or fixing a floating issue, or changing the height on a particular element. But if I'm asked to do something drastic such as, "I want the right sidebars of pages A, B, C and D to have a red border. I want the right side bars of pages E, F and G to have a blue border if and only if the user mouses over", then it takes me time a long time to map out all the CSS inheritance rules to see the "bigger picture". For some reason, I don't encounter the same difficulty with backend code. After a quick debriefing of how a feature works, and a quick inspection of the controller and model code, I will feel comfortable with the architecture. I will think, "it's reasonable to assume that there will be an Employee class that inherits from the Person Class that's used by a Department controller". If I discover inconvenient details that aren't consistent with overall architectural style, I am confident that I can hammer things back in place. With someone else's CSS work, it's much harder for me to see the "relationships" between different classes, and when and how the classes are used. When there are many inheritance rules, I feel overwhelmed. I'm having trouble articulating my question and issues... All I want to know is, why is it so much harder for me to see the bigger picture in someone else's CSS architecture than compared to someone else's business logic layer? **Does it have any thing to do with CSS being a relatively new technology, and there aren't many popular design patterns?

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  • Block diagram containing computer buses,motherboard..

    - by learnerforever
    Hi all, I am trying to understand computer architecture. In particular: - Physical view i.e. what all is packed inside the motherboard and what all outside - Conceptual view. how processor,memory,peripherals are connected. I am getting confused among various buses like local bus,PCI bus, SCSI bus,ISA bus,USB bus. I am looking for block diagrams. How is the USB port connected to processor ultimately? through PCI bus etc? Why do we have so many buses? What was it like before SCSI/IDE came? Does the diagram at : http://www.vaughns-1-pagers.com/computer/pc-block-diagram.htm look correct? It shows no connection between PCI bus and SCSI bus. Is that correct? I would greatly appreciate any other link especially of block diagrams/anatomy and not just textual writeup. Thanks,

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  • Physically moving a hard drive from older iMac (c2d) to new iMac (i7) ?

    - by Inshim
    Instead of my usual habit of using superduper to mirror my drive to a new computer, I just physically moved the hard drive from an older iMac to a new one. But... it now doesn't boot, getting stuck at the apple logo screen. Since the hard drive that came with the new iMac works well, and my old drive works well when I return it to the older iMac, I conclude that there is some problem at the system/kernel level due to the different hardware. In the past I did similar things (e.g. starting a C2D machine from a Core Duo in target disk mode), so perhaps the change in architecture to the i5/i7 is too problematic? The main point: do you know of any way to get the system to rebuild for itself the proper versions of the system components when booting? Are there certain directories that I can safely delete to make that happen? Thanks

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  • Storage servers architectural solution for backup. What is the best way? (pics inside)

    - by Kirzilla
    Hello, What is the best architecture for storage servers array? Needs... a) easy way to add one more server to array b) we don't have single backup server c) we need to have one backup for each "web" part of each server Group #1 : is cross-server-backuping scheme; the main disadvantage that we can't add one more server, we should add 2 servers in one time. Group #2 : is a Group #1, but with three and more servers. It also have a disadvantage - to add one more server we should move existing backup to it. Any suggestions? Thank you. Thank you.

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  • Fresh install of 64bit Ubuntu needs flash but adobe doesn't have a version for me.

    - by DJTripleThreat
    I need flash to watch YT videos. YT said "You need to upgrade your Adobe Flash Player to watch this video." with a link to download flash. I'm running 10.04 so I see possible choices for myself: 1) a .deb file for Ubuntu 8.04+ or APT (whats this??) for Ubuntu 9.04. I downloaded the deb file and when I opened it in the installer it said that I have the wrong architecture. Anyone have an idea about how to work around this?

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  • What hardware is at physical address 0x80000000 on powerpc New World Macintosh?

    - by tinkerer
    Open Firmware device tree gives no clue what device might decode at physical address 0x80000000 to 0x8008200 on a G4 New World Macintosh. The mmu has three adjacent Virtual=Real translations for that block. They are the only address translations reported between the top or physical dram at 20000000 and the start of the PCI bridges at f0000000. (A possible clue is that frame-buffer-addr is reported as 9c008000 by Open Firmware, and that is not in the reported translation table either). I believe the architecture has been around since about 1999.

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  • What does it mean for a computer to be an "IBM Compatible PC"?

    - by Jon
    A couple questions about this: 1) Is this term even relevant any more? 2) Does this mean anything from a developer's stand point? It is not exactly clear to me if this is a BIOS, architecture, bus or a combination. A piece of software I'm working on expects to see a "Description" of the system and currently windows machines report "AT/AT Compatible". Having been tasked to port this to Mac, I really don't know what a proper "Description" would be - this will most likely be omitted but I was wondering if anyone could provide some insight on the modern usage of this term.

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  • channel factory null on debug?

    - by Garrith
    When I try to invoke a GetData contract using wcf rest in wcf test client mode I get this message: The Address property on ChannelFactory.Endpoint was null. The ChannelFactory's Endpoint must have a valid Address specified. at System.ServiceModel.ChannelFactory.CreateEndpointAddress(ServiceEndpoint endpoint) at System.ServiceModel.ChannelFactory`1.CreateChannel() at System.ServiceModel.ClientBase`1.CreateChannel() at System.ServiceModel.ClientBase`1.CreateChannelInternal() at System.ServiceModel.ClientBase`1.get_Channel() at Service1Client.GetData(String value) This is the config file for the host: <system.serviceModel> <services> <service name="WcfService1.Service1" behaviorConfiguration="WcfService1.Service1Behavior"> <!-- Service Endpoints --> <endpoint address="http://localhost:26535/Service1.svc" binding="webHttpBinding" contract="WcfService1.IService1" behaviorConfiguration="webHttp" > <!-- Upon deployment, the following identity element should be removed or replaced to reflect the identity under which the deployed service runs. If removed, WCF will infer an appropriate identity automatically. --> <identity> <dns value="localhost"/> </identity> </endpoint> <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/> </service> </services> <behaviors> <serviceBehaviors> <behavior name="WcfService1.Service1Behavior"> <!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment --> <serviceMetadata httpGetEnabled="true"/> <!-- To receive exception details in faults for debugging purposes, set the value below to true. Set to false before deployment to avoid disclosing exception information --> <serviceDebug includeExceptionDetailInFaults="false"/> </behavior> </serviceBehaviors> <endpointBehaviors> <behavior name="webHttp"> <webHttp/> </behavior> </endpointBehaviors> </behaviors> </system.serviceModel> </configuration> Code: [ServiceContract(Namespace = "")] public interface IService1 { //[WebInvoke(Method = "POST", UriTemplate = "Data?value={value}")] [OperationContract] [WebGet(UriTemplate = "/{value}")] string GetData(string value); [OperationContract] CompositeType GetDataUsingDataContract(CompositeType composite); // TODO: Add your service operations here } public class Service1 : IService1 { public string GetData(string value) { return string.Format("You entered: {0}", value); }

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  • javascript - multiple dependent/cascading/chained select boxes on same form

    - by Aaron
    I'm populating select box options via jquery and json but I'm not sure how to address multiple instances of the same chained select boxes within my form. Because the select boxes are only rendered when needed some records will have ten sets of chained select boxes and others will only need one. How does one generate unique selects to support the auto population of secondary select options? Here's the code I'm using, and I thank you in advance for any insight you may provide. <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript"> function populateACD() { $.getJSON('/acd/acd2json.php', {acdSelect:$('#acdSelect').val()}, function(data) { var select = $('#acd2'); var options = select.attr('options'); $('option', select).remove(); $.each(data, function(index, array) { options[options.length] = new Option(array['ACD2']); }); }); } $(document).ready(function() { populateACD(); $('#acdSelect').change(function() { populateACD(); }); }); </script> <?php require_once('connectvars.php'); $dbc = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME); $squery = "SELECT ACD1ID, ACD1 from ACD1"; $sdata = mysqli_query($dbc, $squery); // Loop through the array of ACD1s, placing them into an option of a select echo '<select name="acdSelect" id="acdSelect">'; while ($row = mysqli_fetch_array($sdata)) { echo "<option value=" . $row['ACD1ID'] . ">" . $row['ACD1'] . "</option>\n"; } echo '</select><br /><br />'; <select name="acd2" id="acd2"> </select> acd2json.php <?php $dsn = "mysql:host=localhost;dbname=wfn"; $user = "acd"; $pass = "***************"; $pdo = new PDO($dsn, $user, $pass); $rows = array(); if(isset($_GET['acdSelect'])) { $stmt = $pdo->prepare("SELECT ACD2 FROM ACD2 WHERE ACD1ID = ? ORDER BY ACD2"); $stmt->execute(array($_GET['acdSelect'])); $rows = $stmt->fetchAll(PDO::FETCH_ASSOC); } echo json_encode($rows); ?>

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  • Config for WCF with multiple endpoints

    - by vdh_ant
    Hi guys I'm new to WCF and am trying to get some ideas I have off the ground. Basically I have a web WCF Application project with the following in its web.config: <system.serviceModel> <services> <service name="WcfService1.ServiceContract.IDirectorySearchService" behaviorConfiguration="defaultServiceBehavior"> <endpoint name="restxml" address="xml" binding="webHttpBinding" contract="WcfService1.ServiceContract.IDirectorySearchServiceXml" behaviorConfiguration="xmlRestBehavior"/> <endpoint name="restjson" address="json" binding="webHttpBinding" contract="WcfService1.ServiceContract.IDirectorySearchServiceJson" behaviorConfiguration="jsonRestBehavior"/> <endpoint name="soap" address="soap" binding="basicHttpBinding" contract="WcfService1.ServiceContract.IDirectorySearchService"/> <endpoint name="mex" address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/> </service> </services> <behaviors> <serviceBehaviors> <behavior name="defaultServiceBehavior"> <serviceDebug includeExceptionDetailInFaults="true"/> </behavior> </serviceBehaviors> <endpointBehaviors> <behavior name="xmlRestBehavior"> <webHttp/> </behavior> <behavior name="jsonRestBehavior"> <enableWebScript/> </behavior> </endpointBehaviors> </behaviors> </system.serviceModel> My interfaces look like this: [ServiceContract] public interface IDirectorySearchServiceXml { [OperationContract] [WebGet(UriTemplate = "Search/")] SearchResults Search(); } [ServiceContract] public interface IDirectorySearchServiceJson { [OperationContract] [WebGet(UriTemplate = "Search/")] SearchResults Search(); } [ServiceContract] public interface IDirectorySearchService { [OperationContract] SearchResults Search(int? sportId, int? instituteId, DateTime? startDate, DateTime? endDate); } Now the part I am having a little trouble with is what else I need to get this up and running... Like given this what .svc files do I need and do I have the config right... Also what addresses do I need to use to get this running either through the browser or through the WCF test client. Note I am currently using 3.5. Cheers Anthony

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  • jquery ajax, array and json

    - by sea_1987
    I am trying to log some input values into an array via jquery and then use those to run a method server side and get the data returned as JSON. The HTML looks like this, <div class="segment"> <div class="label"> <label>Choose region: </label> </div> <div class="column w190"> <div class="segment"> <div class="input"> <input type="checkbox" class="radio" value="Y" name="area[Nationwide]" id="inp_Nationwide"> </div> <div class="label "> <label for="inp_Nationwide">Nationwide</label> </div> <div class="s">&nbsp;</div> </div> </div> <div class="column w190"> <div class="segment"> <div class="input"> <input type="checkbox" class="radio" value="Y" name="area[Lancashire]" id="inp_Lancashire"> </div> <div class="label "> <label for="inp_Lancashire">Lancashire</label> </div> <div class="s">&nbsp;</div> </div> </div> <div class="column w190"> <div class="segment"> <div class="input"> <input type="checkbox" class="radio" value="Y" name="area[West_Yorkshire]" id="inp_West_Yorkshire"> </div> <div class="label "> <label for="inp_West_Yorkshire">West Yorkshire</label> </div> <div class="s">&nbsp;</div> </div> <div class="s">&nbsp;</div> </div> I have this javascript the detect whether the items are checked are not if($('input.radio:checked')){ } What I dont know is how to get the values of the input into an array so I can then send the information through AJAX to my controller. Can anyone help me?

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