Search Results

Search found 43820 results on 1753 pages for 'web browsing'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 33/1753 | < Previous Page | 29 30 31 32 33 34 35 36 37 38 39 40  | Next Page >

  • Technology/Techniques to prevent offensive images on a website

    - by Andreas Siegers
    I am planing to build a website which one of its main features is the usage of pictures. I was wondering what existing techniques are used to prevent offensive pictures (i.e pornography) to get loaded by users. i.e What does Facebook or Pinterest use? As well I would like to know what your recommendations would be to control offensive pictures to get uploaded to the site (OpenSource tools maybe..) Taking into consideration this is a personal project and will be developed with a very small budget. Thank you

    Read the article

  • Lots of Internet browsing issues, all browsers

    - by dario_ramos
    Before the upgrade, everything was working fine. Now, however, I can connect to the Internet but a lot of stuff fails, and the weirdest thing is that it happens with Firefox, Chromium and Opera. Some of the things that fail: I can't log in to Stack Overflow, after entering user/pass it loads for a long time on Firefox and throws Error 408 (browser request timed out) on Chromium and Opera I can't log in to Hotmail, similar symptoms I can login to Facebook, but when I try to write a comment, or just post something in my wall, it stays loading for a long time, and then fails The first two issues seem to be related to secure pages, and the second one is another issue altogether, I believe. However, they all happen with all browsers, which is really weird. Talking about weird: I connect using a Huawei SmartAX MT 810 USB modem, which cost me blood and tears to get it working under Ubuntu. I ordered an ethernet modem/router with my ISP, and I'm still waiting, but this issue intrigues me anyway. Has anyone experienced this kind of problems? I Googled around, but couldn't find a similar case.

    Read the article

  • I want to create an e-learning website [closed]

    - by Viswa
    I want to create an e-learning website and host it. (Maybe after some time I want to add forms.) These are the things I know: java, jsp, servlet, html (not guru, almost beginner). I don't have experience in creating websites, I did my college project using jsp,servlet and jdbc. What are the things or technology I need to know before creating website. Is it possible to create a website by one person?

    Read the article

  • JS / HTML 5 Compatablity issue on iOS 6

    - by Dhaval
    I'm using HTML 5 to play video and there are some content before the video so I'm using flexroll to scroll that whole window. I'm checking it on iPad, now problem is that in iOS 5 its working fine but when I update to iOS 6 then screen is not scrolling only video is scroll up and down, content is as it is in the position. I can't understand what is the exact problem. Is that js compatibility issue or HTML 5 video compatibility issue. Can anyone please help me to figure out, your help will really be appreciated.

    Read the article

  • Is it legal or good idea to have a backup of all client sites on my own server

    - by mario
    I have seen many times that if we build a website for a client then there is a possibility that this site gets changed over a period of time. I was thinking that from now onwards whichever site I make I will host a copy of the site on a personal server. Like client1.myserver.com so that even if they change it I have the copy of it. So that if I need to show someone or I need to refer myself few things I have the proof there. I will not make them public but will password protect it. I want to know whether this is legal and a good idea or not.

    Read the article

  • Is there any software to clip a website, make changes to the code and republish it?

    - by user1445919
    I am working in the front end of an application and we provide the interface between the customers and several backend services. We have been using Kapow software to clip the html/jsp code we receive from the backend, make the necessary changes and publish them on the main website. I wanted to know if there is any other alternative to this software which suffices our requirement. Also, are any of those open source?

    Read the article

  • How can I get non-programmer colleagues on board with bespoke software rather than Dynamics CRM + Sharepoint?

    - by Bendos
    I am working with a company which designs and builds one-off machines. They have been 'dabbling' with hosted Dynamics CRM and Sharepoint (on different servers!) in an attempt to centralise their data and help colleagues collaborate more effectively across projects. They haven't used either system to their potential. Now we are looking at the engineering department who already use a form of version control software for the various CAD files (Autodesk Vault) however it is becoming increasingly necessary to implement more of a generic file version control system as they use many more files than can be managed in Vault (sometimes just photos or scans of paper documents), hence why they were looking at using Sharepoint. However... as the 'programmer' of the bunch, I can see several scenarios which don't seem to fit well with the Dynamics + Sharepoint approach; simple reports based on cross-table queries, exporting certain metrics as a spreadsheet, defining project hierarchies and many-many relationships, and as such I have been pushing for an in-house developed 'ECM' / 'ERP' software package (perhaps in .NET or php). Some colleagues seem to attach a greater value to the MS software (perhaps becuase it has a logo!) but don't see that it's just a framework, not a solution. Can anyone provide a good example of when custom software would actually be better than using Dynamics + Sharepoint and how do I relate that to non-technical staff?

    Read the article

  • Pending and Approval process

    - by zen
    So let's say I have a DB table with 8 columns, one is a unique auto-incrementing used as ID. So I have a page that pulls in the info for each row based on query string ID. I want to give my users the ability to propose changes. Kinda like a wiki setup. So I was thinking I should just have another duplicate table or maybe database altogether (without the auto-incrementing column and maybe with a date edited column) that keeps all proposed changes in queue and then when I approve them, the script can move the row from the proposed DB to the real DB. Does this sound good or is there a better process for this?

    Read the article

  • Web programming, standard way to deal with a response that takes time to complete

    - by wobbily_col
    With normal form submission I use the pattern Post / Redirect / Get, when processing the forms. I have a database application built with Django. I want to allow the users to select a number of items from the database, then launch a computationally intensive task based on those items. I expect the task to take between 10 minutes and 2 hours to complete. Is there a standard approach to dealing with requests like this (i.e. that don't return immediately)? Ideally there would be some way to display the progress.

    Read the article

  • secure offline PC storage accessible through javascript

    - by turbo2oh
    I'm attempting to build a browser-based HTML5 application that has the ability to store data locally on a PC (not mobile device) when offline. This data is sensitive and must be secure. Of course the trick is trying to find a way to be able to access the secure data with Javascript. I've ruled out browser local storage since its not secure. Could this be accomplished with a local database? If so, where could the DB credentials be stored? Javascript obviously doesn't seem like a good option to store them since its user-readable.

    Read the article

  • Microsoft précise l'avenir de ses technologies de développement Web ASP.NET Web Forms, Web API, MVC et applications Facebook

    Microsoft précise l'avenir de ses technologies de développement Web ASP.NET Web Forms, Web API, MVC et applications Facebook Microsoft précise sa vision pour ASP.NET et publie une feuille de route traçant l'avenir de l'ensemble de ses technologies de développement Web. Les plans prévoient notablement de meilleurs templates et des progrès sur les fonctionnalités OData dans ASP.NET Web API. [IMG]http://ww1.prweb.com/prfiles/2012/03/08/9268042/gI_83262_best-aspnet-web-hosting.png[/IMG] Selon le site du projet CodePlex, ces plans ne seraient en fait que des prévisions que les développeurs de Microsoft aspirent d'atteindre. Ce n'est en aucun cas des spécifications à s...

    Read the article

  • The very beggining research for web developing

    - by stckxchng
    It is a general question to ask what would be the easiest way to start a website, however every one need a little boost up at the begging. There are content management systems, or admin panels, or some people have developed their own systems and many more diffirent things people use at the very beggining. Among others my way was looking for a very lightweight cms and develop a system on to it, unfortunately I couldn't find a good system to develop on, for example I decided to develop on snewscms (the lightest weight cms) but it is really hard to manage since it is not developed with object oriented programming standarts and I thought it would be a mistake to continue developing on to such a system. On the other hand starting to code from the core would be weak about security, and using a massive cms like joomla or drupal will not be good since there will be many things that are unused and moreover I will not feel well when I don't know what I am controlling since it is not easy to know every part of them. What I am asking is what would you do if you had lost all the files you are currently using today, where would you start from? What tool would you use? Or is there a lightweight and well coded tool to get start with?

    Read the article

  • web service host [closed]

    - by elyashiv
    I'm looking for a place to host a cloud service that well manage data from a App I'm developing. The service I need doesn't have any UI (accessed completely through the App software), and well work on only small requests - but hopefully quite a lot of them. I'm looking for something free that well give me the best - in storage and request handling. No specific language, but preferably one of the following: Python, C#, Java. (in this order).

    Read the article

  • ????????WebLogic Server - Web????|WebLogic Channel|??????

    - by ???02
    WebLogic Server????????????????????????????WebLogic Server?Web????????????????Web????????????????????????????????????WebLogic Server???JAX-RPC??????????JAX-WS??????????????????Web??????????WebLogic???????????JAX-WS?????Web?????????????????????????¦Web??????¦Web??????/????/??¦WebLogic Server 10.3.x?Web???????¦JAX-WS Stack ???/JAX-RPC Stack ???¦??????¦JAX-WS??/JAX-WS?JAX-PRC???¦JAX-WS???WebLogic Web ????????????????????????????????????[pdf]WebLogic Server - Web??????

    Read the article

  • Could not load file or assembly 'System.Web.Ajax, Version=3.0.31106.0

    - by Jonesy
    HI folks, I have a .net application (vb.net) and I'm using the ajax control toolkit. It works fine on my production machine but when I upload it to the host (fasthosts) i get this error: Could not load file or assembly 'System.Web.Ajax, Version=3.0.31106.0, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e' or one of its dependencies. The module was expected to contain an assembly manifest. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.BadImageFormatException: Could not load file or assembly 'System.Web.Ajax, Version=3.0.31106.0, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e' or one of its dependencies. The module was expected to contain an assembly manifest. Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Assembly Load Trace: The following information can be helpful to determine why the assembly 'System.Web.Ajax, Version=3.0.31106.0, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e' could not be loaded. WRN: Assembly binding logging is turned OFF. To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1. Note: There is some performance penalty associated with assembly bind failure logging. To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog]. Stack Trace: [BadImageFormatException: Could not load file or assembly 'System.Web.Ajax, Version=3.0.31106.0, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e' or one of its dependencies. The module was expected to contain an assembly manifest.] AjaxControlToolkit.ToolkitScriptManager.ApplyAssembly(ScriptReference script, Boolean isComposite) +0 AjaxControlToolkit.ToolkitScriptManager.OnResolveScriptReference(ScriptReferenceEventArgs e) +167 System.Web.UI.ScriptManager.RegisterScripts() +191 System.Web.UI.ScriptManager.OnPagePreRenderComplete(Object sender, EventArgs e) +113 System.Web.UI.Page.OnPreRenderComplete(EventArgs e) +8698462 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1029 Here is my web.conf file. Its very simple: <system.web> <customErrors mode="Off"/> <compilation debug="true"> <assemblies> <add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add assembly="System.Web.Extensions.Design, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/> <add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/></assemblies></compilation></system.web> Does anyone know whats up? -- Billy

    Read the article

  • Import web.go error after using goinstall

    - by Metropolis
    With halfdans advice, I was successfully able to use goinstall github.com/hoisie/web.go without any errors after installing git first. However, now when I try to compile the sample code given, go is not finding the web package. I get the error, main.go:4: can't find import: web On this code package main import ( "web" ) func hello(val string) string { return "hello " + val } func main() { web.Get("/(.*)", hello) web.Run("0.0.0.0:9999") } Is there something special I need to do in order for it to recognize the package? I found the package source at $GOROOT/src/pkg/github.com/hoisie/web.go/web. I tried github.com/hoisie/web.go/web as the import and it still did not like that.

    Read the article

  • What exception is thrown if a web service i'm using Times Out?

    - by BT
    I'm calling a .NET web service within my existing .NET webservice, i would like to know what exception is thrown from the web method if timeout happens, i have set the web service timeout to some lower value then the default 90 sec. and want to add business logic if time out happens. Is this the exception i should be looking at? System.Net.WebException

    Read the article

  • Silverlight/Web Service Serializing Interface for use Client Side

    - by Steve Brouillard
    I have a Silverlight solution that references a third-party web service. This web service generates XML, which is then processed into objects for use in Silverlight binding. At one point we the processing of XML to objects was done client-side, but we ran into performance issues and decided to move this processing to the proxies in the hosting web project to improve performance (which it did). This is obviously a gross over-simplification, but should work. My basic project structure looks like this. Solution Solution.Web - Holds the web page that hosts Silverlight as well as proxies that access web services and processes as required and obviously the references to those web services). Solution.Infrastructure - Holds references to the proxy web services in the .Web project, all genned code from serialized objects from those proxies and code around those objects that need to be client-side. Solution.Book - The particular project that uses the objects in question after processed down into Infrastructure. I've defined the following Interface and Class in the Web project. They represent the type of objects that the XML from the original third-party gets transformed into and since this is the only project in the Silverlight app that is actually server-side, that was the place to define and use them. //Doesn't get much simpler than this. public interface INavigable { string Description { get; set; } } //Very simple class too public class IndexEntry : INavigable { public List<IndexCM> CMItems { get; set; } public string CPTCode { get; set; } public string DefinitionOfAbbreviations { get; set; } public string Description { get; set; } public string EtiologyCode { get; set; } public bool HighScore { get; set; } public IndexToTabularCommandArguments IndexToTabularCommandArgument { get; set; } public bool IsExpanded { get; set; } public string ManifestationCode { get; set; } public string MorphologyCode { get; set; } public List<TextItem> NonEssentialModifiersAndQualifyingText { get; set; } public string OtherItalics { get; set; } public IndexEntry Parent { get; set; } public int Score { get; set; } public string SeeAlsoReference { get; set; } public string SeeReference { get; set; } public List<IndexEntry> SubEntries { get; set; } public int Words { get; set; } } Again; both of these items are defined in the Web project. Notice that IndexEntry implments INavigable. When the code for IndexEntry is auto-genned in the Infrastructure project, the definition of the class does not include the implmentation of INavigable. After discovering this, I thought "no problem, I'll create another partial class file reiterating the implmentation". Unfortunately (I'm guessing because it isn't being serialized), that interface isn't recognized in the Infrastructure project, so I can't simply do that. Here's where it gets really weird. The BOOK project CAN see the INavigable interface. In fact I use it in Book, though Book has no reference to the Web Service in the Web project where the thing is define, though Infrastructure does. Just as a test, I linked to the INavigable source file from indside the Infrastructure project. That allowed me to reference it in that project and compile, but causes havoc in the Book project, because now there's a conflick between the one define in Infrastructure and the one defined in the Web project's web service. This is behavior I would expect. So, to try and sum up a bit. Web project has a web service that process data from a third-party service and has a class and interface defined in it. The class implements the interface. The Infrastructure project references the web service in the Web Project and the Book project references the Infrastructure project. The implmentation of the interface in the class does NOT serialize down, so the auto-genned code in INfrastructure does not show this relationship, breaking code further down-stream. The Book project, whihc is further down-stream CAN see the interface as defined in the Web Project, even though its only reference is through the Infrastructure project; whihc CAN'T see it. Am I simple missing something easy here? Can I apply an attribute to either the Interface definition or to the its implmentation in the class to ensure its visibility downstream? Anything else I can do here? I know this is a bit convoluted and anyone still with me here, thanks for your patience and any advice you might have. Cheers, Steve

    Read the article

  • What are "web services"?

    - by Kevin
    I'm reading a book about programming ASP.NET in C#. The book makes the following comment: Previous editions of this book tackled web services, a feature that allows you to create code routines that can be called by other applications over the Internet.Web services are more interesting when considering rich client development (because they allow you to give web features to ordinary desktop applications),and they’re in the process of being replaced by a new technology known as WCF (Windows Communication Foundation). For those reasons, web services aren’t covered in this book.However,if you want to branch out and explore the web service world,you can download the web service chapters from the previous edition of this book from the book’s download page.The information in these chapters still applies to ASP.NET 3.5,because the web service feature hasn’t changed. Can someone offer, in "layman's terms" what exactly a web service is and if, indeed, they are being replaced, at least in .Net, with WCF? What would be a practical example of a web service? Are they stand alone programs that run on a web server and are invoked by a client or clients?

    Read the article

  • Is it me or is developing web based data entry GUIs a big pain?

    - by GregH
    Maybe it's me or maybe it isn't. I don't have a huge amount of experience of developing web based data entry software but do have some. I used to do it quite a bit years ago. Used to use Oracle Forms, Visual Studio, various 4th generation languages, and performing the user interface layout used to be a snap. Now doing the user interface for developing web applications seems to be a huge pain in the rear. Just trying to get text entry fields and widgets to go where they are supposed to go on the screen is a total pain. You have to know Javascript, CSS, JQuery, HTML, etc. There must be an easier way to develop data entry forms that produce the needed underlying code for a web page. Maybe I'm just not looking in the right place. There must be some WYSIWYG GUI development tools for the web for developing data entry forms out there. Anybody know of any?

    Read the article

  • best approah (security) to do some admin work through web page in Linux?

    - by Data-Base
    Hello, I want to build a web based admin tools that allow the system admin to run pre-configured commands and scripts through a web page (simple and limited webmin), what is the best approach? I already started with Ubuntu installing LAMP and give the user www-data root's privileges !!! as I learned (please check the link) this is a really bad move !!!, so how to build such web-based system without the security risk? cheers

    Read the article

  • Maven Grails web.xml

    - by dunn less
    Might be a stupid question, but in my current maven project i do not have a web.xml in my /web-app/WEB-INF folder. There is no web-xml in my project and never has been, im trying to add it but my application is non-responsive to anything written in the web.xml. What am i missing?, iv tried specifying the path to it through the config.groovy like: grails.project.web.xml="web-app/WEB-INF/web.xml" Am i missing something? Do i need to specify the web.xml in some other config file in order to make my project utilize it ?

    Read the article

  • 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.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 29 30 31 32 33 34 35 36 37 38 39 40  | Next Page >