Search Results

Search found 37966 results on 1519 pages for 'string compare'.

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 251/1519 | < Previous Page | 247 248 249 250 251 252 253 254 255 256 257 258  | Next Page >

  • what is the purpose of numeric/boolean/string objects as opposed to primitive values?

    - by zespri
    In javascript you can call a function as a function or as a constructor. For example you can do : myObject = new Number(13); myPrimitiveValue = Number(13); or simply myPrimitiveValue = 13; I understand the difference between the results. Can you explain me under which reasonable circumstances creating a number, a boolean or a string as an object is desirable? For example, ability to set new properties (this is something you can do on objects but can't really do on primitive values) is almost always a bad idea for objects containing number/boolean/string. Why would I want a numeric/boolean/string object?

    Read the article

  • Easy way to cast an object array into another type in C#

    - by Na7coldwater
    I want to be able to be able to quickly cast an array of objects to a different type, such as String, but the following code doesn't work: String[] a = new String[2]; a[0] = "Hello"; a[1] = "World"; ArrayList b = new ArrayList(a); String[] c = (String[]) b.ToArray(); And I don't want to have to do this: String[] a = new String[2]; a[0] = "Hello"; a[1] = "World"; ArrayList b = new ArrayList(a); Object[] temp = b.ToArray(); Object[] temp = b.ToArray(); String[] c = new String[temp.Length]; for(int i=0;i<temp.Length;i++) { c[i] = (String) temp[i]; } Is there an easy way to do this without using a temporary variable?

    Read the article

  • How do I compare 2 fields and return the lowest value of each record?

    - by BigRob
    I'm slowly learning access to make a database of products and suppliers for my parents' business. What i've got is a table of products indexed by our product reference and 2 more tables for 2 different suppliers that contains the suppliers product reference and price that links with our reference. I've made a query that performs a left outer join such that it returns a table of our products with each supplier's reference and price, i.e: Ref | Product Name | Supplier 1 Ref | Supplier 1 Price | Supplier 2 Ref | Supplier 2 Price Here's the query I used: SELECT Catalog.Ref, Catalog.[Product Name], Catalog.Price, [D Products].[Supplier Ref], [D Products].Cost, [GS Products].[Supplier Ref], [GS Products].Cost FROM ([Catalog] LEFT JOIN [D Products] ON Catalog.Ref = [D Products].Ref) LEFT JOIN [GS Products] ON Catalog.Ref = [GS Products].Ref; Not all products are available from both suppliers, hence the outer join. What I want to do (with a query?) is to take the table produced by the query above and simply show the product reference, cheapest supplier reference and cheapest supplier price, i.e: Ref | Cheapest Suppplier Ref | Cheapest Supplier Price Unfortunately my SQL knowledge isn't quite good enough to figure this out, but if anyone can help i'd really appreciate it. Thanks, Rob

    Read the article

  • How to compare the year with the current year in iphone?

    - by Warrior
    I am new to iphone development.I am parsing a XML URL and display the title ,date and summary in a table view.I noticed some of the date were very old like "Wed, 31 Dec 1969 19:00:00 -0500" ,So i don't want to display the dates which are 1 year older than the current year.How to do that? I used the sample code from this site for parsing and display the details.Please help me out.Thanks.

    Read the article

  • Core Animation cross-dissolve between one string (or image) and another when changing bound value?

    - by danwood
    I have an NSTextView and an NSImageView that is bound to a NSString and an NSImage in my code. I would like to have the displayed string and image cross-dissolve when I change the string and image in code. Any way to do this? Do I need to stop using bindings? (And if I do, is there any trick to getting the string and the image to cross-dissolve when I change the value, or do I have to do something weird like fade it out and fade a new one back in?)

    Read the article

  • Is there a way to create a string that matches a given C# regex?

    - by Chris Phillips
    My application has a feature that parses text using a regular expression to extract special values. I find myself also needing to create strings that follow the same format. Is there a way to use the already defined regular expression to create those strings? For example, assume my regex looks something like this: public static Regex MyRegex = new Regex( @"sometext_(?<group1>\d*)" ); I'd like to be able to use MyRegex to create a new string, something like: var created = MyRegex.ToString( new Dictionary<string, string>() {{ "group1", "data1" }}; Such that created would then have the value "sometextdata1".

    Read the article

  • How do I display/compare a dynamic value of a mysql row in a if statement?

    - by Ralph The Mouf
    I have a checkboxes on my site that when unchecked, update their row in in the db as unchecked, and if checked,update their row in the db as checked. I am creating an ifstatement that will commence with its command if checked, and not if unchecked. I have echoed the variable and it is holding the proper value (checked or unchecked) but not sure if I am syntactically correct on displaying the state of the row in the db. This is what I am trying and will not work. I am new at php still and thank you very much for any help. if($auth->check_prof == 'checked'){// do the stuff in here}

    Read the article

  • Java Error When correct code is put together

    - by Eric
    I have a few string problems that I need to put together for a complete homework assignment. They all work correctly by themselves, but when I put them together in the main function, the last one that finds the smallest word in a string gives an error. Anyone know why? public static void main(String[] args){ Scanner sc = new Scanner(System.in); //Length of Word String word1 = sc.next(); System.out.println(word1.length()); //Evens in one string odds in the other String word2 = sc.next(); StringBuilder even = new StringBuilder(); StringBuilder odd = new StringBuilder(); for(int i = 0; i < word2.length(); i++){ if(i % 2 == 0){ even.append(word2.charAt(i)); } else{ odd.append(word2.charAt(i)); } } System.out.println(even + " " + odd); //Diminishing Suffix String word3 = sc.next(); for(int j = 0; j < word3.length(); j++){ System.out.print(word3.substring(j, word3.length()) + " "); } System.out.printf("\n"); //Letter Replacement String word4 = sc.next(); String word5 = sc.next(); String word6 = sc.next(); String word7 = word4.replace(word5, word6); System.out.println(word7); //How many times x appears in xstring String word8 = sc.next(); String word9 = sc.next(); int index = word8.indexOf(word9); int count = 0; while (index != -1) { count++; word8 = word8.substring(index + 1); index = word8.indexOf(word9); } System.out.println(count); System.out.println(); //Lexicographically smallest word String Sentence = sc.nextLine(); String[] myWords = Sentence.split(" "); int shortestLengths, shortestLocation; shortestLengths=(myWords[1]).length(); shortestLocation=1; for (int i = 1; i <myWords.length; i++) { if ((myWords[i]).length() < shortestLengths) { shortestLengths=(myWords[i]).length(); shortestLocation=i; } } System.out.println(myWords[shortestLocation]); } } Talking about the lexicographically smallest one

    Read the article

  • Yii CGridView: how to add a static WHERE condtion?

    - by realtebo
    I've a standard Gii created admin view, which use a CGridView, and it's showing my user table data. the problem is that user with name 'root' must NOT BE VISIBLE. Is there a way to add a static where condition " ... and username !='root' " ? admin.php [view] 'columns'=>array( 'id', 'username', 'password', 'realname', 'email', ..... user.php [model] public function search() { // Warning: Please modify the following code to remove attributes that // should not be searched. $criteria=new CDbCriteria; $criteria->compare('id',$this->id); $criteria->compare('username',$this->username,true); $criteria->compare('password',$this->password,true); $criteria->compare('realname',$this->realname,true); $criteria->compare('email',$this->email,true); ...... return new CActiveDataProvider($this, array( 'criteria'=>$criteria, )); }

    Read the article

  • How to get radio button's id and convert to string?

    - by user3461659
    I am working in Android Studio and am trying to get the ID of the selected radio button and then store the ID in a string. Is this possible? I have tried replacing the .getText() method below with .getId() but it wont let me store it as a string: RadioGroup radioGroup = (RadioGroup) findViewById(R.id.radioGroup); radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { @Override public void onCheckedChanged(RadioGroup radioGroup, int checkedId) { RadioButton checkedRadioButton = (RadioButton) findViewById(checkedId); String text = checkedRadioButton.getText().toString(); Toast.makeText(getApplicationContext(), text, Toast.LENGTH_SHORT).show(); } });

    Read the article

  • SharePoint threw "Unknown SQL Exception 206 occured." Anyone familiar with this?

    - by dalehhirt
    Our SharePoint instance threw the following errors when attempting to access data through a Content Query Tool: 04/02/2010 10:45:06.12 w3wp.exe (0x062C) 0x1734 Windows SharePoint Services Database 5586 Critical Unknown SQL Exception 206 occured. Additional error information from SQL Server is included below. Operand type clash: uniqueidentifier is incompatible with datetime 04/02/2010 10:45:06.25 w3wp.exe (0x062C) 0x1734 Office Server Office Server General 900n Critical A runtime exception was detected. Details follow. Message: Operand type clash: uniqueidentifier is incompatible with datetime Techinal Details: System.Data.SqlClient.SqlException: Operand type clash: uniqueidentifier is incompatible with datetime at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) at System.Data.SqlClient.SqlDataReader.ConsumeMetaData(... 04/02/2010 10:45:06.25* w3wp.exe (0x062C) 0x1734 Office Server Office Server General 900n Critical ...) at System.Data.SqlClient.SqlDataReader.get_MetaData() at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) at System.Data.SqlClient.SqlC 04/02/2010 10:45:06.25 w3wp.exe (0x062C) 0x1734 CMS Publishing 8vyd Exception (Watson Reporting Cancelled) System.Data.SqlClient.SqlException: Operand type clash: uniqueidentifier is incompatible with datetime at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) at System.Data.SqlClient.SqlDataReader.ConsumeMetaData() at System.Data.SqlClient.SqlDataReader.get_MetaData() at System.Data.SqlClient.SqlCommand.FinishExecuteRead... 04/02/2010 10:45:06.25* w3wp.exe (0x062C) 0x1734 CMS Publishing 8vyd Exception ...er(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior) at Microsoft.SharePoint.Utilities.SqlSession.ExecuteReader(SqlCommand command, ... 04/02/2010 10:45:06.25* w3wp.exe (0x062C) 0x1734 CMS Publishing 8vyd Exception ...CommandBehavior behavior) at Microsoft.SharePoint.SPSqlClient.ExecuteQuery(Boolean& bSucceed) at Microsoft.SharePoint.Library.SPRequestInternalClass.CrossListQuery(String bstrUrl, String bstrXmlWebs, String bstrXmlLists, String bstrXmlQuery, ISP2DSafeArrayWriter pCallback, Object& pvarColumns) at Microsoft.SharePoint.Library.SPRequest.CrossListQuery(String bstrUrl, String bstrXmlWebs, String bstrXmlLists, String bstrXmlQuery, ISP2DSafeArrayWriter pCallback, Object& pvarColumns) at Microsoft.SharePoint.SPWeb.GetSiteData(SPSiteDataQuery query) at Microsoft.SharePoint.Publishing.CachedArea.GetCrossListQuery(SPSiteDataQuery query, SPWeb currentContext) at Microsoft.SharePoint.Publishing.CrossListQueryCache.GetSiteData(CachedArea cachedArea, SPWeb web, SPSiteDataQuery qu... 04/02/2010 10:45:06.25* w3wp.exe (0x062C) 0x1734 CMS Publishing 8vyd Exception ...ery) 04/02/2010 10:45:06.25 w3wp.exe (0x062C) 0x1734 CMS Publishing 78ed Warning Error occured while processing a Content Query Web Part. Performing the following query ' 04/02/2010 10:45:06.25* w3wp.exe (0x062C) 0x1734 CMS Publishing 78ed Warning ...ue" Type="Number"/ The farm is MOSS 2007 with SQL Server 2005 backend. Any ideas are welcomed. Dale

    Read the article

  • Passing multiple POST parameters to Web API Controller Methods

    - by Rick Strahl
    ASP.NET Web API introduces a new API for creating REST APIs and making AJAX callbacks to the server. This new API provides a host of new great functionality that unifies many of the features of many of the various AJAX/REST APIs that Microsoft created before it - ASP.NET AJAX, WCF REST specifically - and combines them into a whole more consistent API. Web API addresses many of the concerns that developers had with these older APIs, namely that it was very difficult to build consistent REST style resource APIs easily. While Web API provides many new features and makes many scenarios much easier, a lot of the focus has been on making it easier to build REST compliant APIs that are focused on resource based solutions and HTTP verbs. But  RPC style calls that are common with AJAX callbacks in Web applications, have gotten a lot less focus and there are a few scenarios that are not that obvious, especially if you're expecting Web API to provide functionality similar to ASP.NET AJAX style AJAX callbacks. RPC vs. 'Proper' REST RPC style HTTP calls mimic calling a method with parameters and returning a result. Rather than mapping explicit server side resources or 'nouns' RPC calls tend simply map a server side operation, passing in parameters and receiving a typed result where parameters and result values are marshaled over HTTP. Typically RPC calls - like SOAP calls - tend to always be POST operations rather than following HTTP conventions and using the GET/POST/PUT/DELETE etc. verbs to implicitly determine what operation needs to be fired. RPC might not be considered 'cool' anymore, but for typical private AJAX backend operations of a Web site I'd wager that a large percentage of use cases of Web API will fall towards RPC style calls rather than 'proper' REST style APIs. Web applications that have needs for things like live validation against data, filling data based on user inputs, handling small UI updates often don't lend themselves very well to limited HTTP verb usage. It might not be what the cool kids do, but I don't see RPC calls getting replaced by proper REST APIs any time soon.  Proper REST has its place - for 'real' API scenarios that manage and publish/share resources, but for more transactional operations RPC seems a better choice and much easier to implement than trying to shoehorn a boatload of endpoint methods into a few HTTP verbs. In any case Web API does a good job of providing both RPC abstraction as well as the HTTP Verb/REST abstraction. RPC works well out of the box, but there are some differences especially if you're coming from ASP.NET AJAX service or WCF Rest when it comes to multiple parameters. Action Routing for RPC Style Calls If you've looked at Web API demos you've probably seen a bunch of examples of how to create HTTP Verb based routing endpoints. Verb based routing essentially maps a controller and then uses HTTP verbs to map the methods that are called in response to HTTP requests. This works great for resource APIs but doesn't work so well when you have many operational methods in a single controller. HTTP Verb routing is limited to the few HTTP verbs available (plus separate method signatures) and - worse than that - you can't easily extend the controller with custom routes or action routing beyond that. Thankfully Web API also supports Action based routing which allows you create RPC style endpoints fairly easily:RouteTable.Routes.MapHttpRoute( name: "AlbumRpcApiAction", routeTemplate: "albums/{action}/{title}", defaults: new { title = RouteParameter.Optional, controller = "AlbumApi", action = "GetAblums" } ); This uses traditional MVC style {action} method routing which is different from the HTTP verb based routing you might have read a bunch about in conjunction with Web API. Action based routing like above lets you specify an end point method in a Web API controller either via the {action} parameter in the route string or via a default value for custom routes. Using routing you can pass multiple parameters either on the route itself or pass parameters on the query string, via ModelBinding or content value binding. For most common scenarios this actually works very well. As long as you are passing either a single complex type via a POST operation, or multiple simple types via query string or POST buffer, there's no issue. But if you need to pass multiple parameters as was easily done with WCF REST or ASP.NET AJAX things are not so obvious. Web API has no issue allowing for single parameter like this:[HttpPost] public string PostAlbum(Album album) { return String.Format("{0} {1:d}", album.AlbumName, album.Entered); } There are actually two ways to call this endpoint: albums/PostAlbum Using the Model Binder with plain POST values In this mechanism you're sending plain urlencoded POST values to the server which the ModelBinder then maps the parameter. Each property value is matched to each matching POST value. This works similar to the way that MVC's  ModelBinder works. Here's how you can POST using the ModelBinder and jQuery:$.ajax( { url: "albums/PostAlbum", type: "POST", data: { AlbumName: "Dirty Deeds", Entered: "5/1/2012" }, success: function (result) { alert(result); }, error: function (xhr, status, p3, p4) { var err = "Error " + " " + status + " " + p3; if (xhr.responseText && xhr.responseText[0] == "{") err = JSON.parse(xhr.responseText).message; alert(err); } }); Here's what the POST data looks like for this request: The model binder and it's straight form based POST mechanism is great for posting data directly from HTML pages to model objects. It avoids having to do manual conversions for many operations and is a great boon for AJAX callback requests. Using Web API JSON Formatter The other option is to post data using a JSON string. The process for this is similar except that you create a JavaScript object and serialize it to JSON first.album = { AlbumName: "PowerAge", Entered: new Date(1977,0,1) } $.ajax( { url: "albums/PostAlbum", type: "POST", contentType: "application/json", data: JSON.stringify(album), success: function (result) { alert(result); } }); Here the data is sent using a JSON object rather than form data and the data is JSON encoded over the wire. The trace reveals that the data is sent using plain JSON (Source above), which is a little more efficient since there's no UrlEncoding that occurs. BTW, notice that WebAPI automatically deals with the date. I provided the date as a plain string, rather than a JavaScript date value and the Formatter and ModelBinder both automatically map the date propertly to the Entered DateTime property of the Album object. Passing multiple Parameters to a Web API Controller Single parameters work fine in either of these RPC scenarios and that's to be expected. ModelBinding always works against a single object because it maps a model. But what happens when you want to pass multiple parameters? Consider an API Controller method that has a signature like the following:[HttpPost] public string PostAlbum(Album album, string userToken) Here I'm asking to pass two objects to an RPC method. Is that possible? This used to be fairly straight forward either with WCF REST and ASP.NET AJAX ASMX services, but as far as I can tell this is not directly possible using a POST operation with WebAPI. There a few workarounds that you can use to make this work: Use both POST *and* QueryString Parameters in Conjunction If you have both complex and simple parameters, you can pass simple parameters on the query string. The above would actually work with: /album/PostAlbum?userToken=sekkritt but that's not always possible. In this example it might not be a good idea to pass a user token on the query string though. It also won't work if you need to pass multiple complex objects, since query string values do not support complex type mapping. They only work with simple types. Use a single Object that wraps the two Parameters If you go by service based architecture guidelines every service method should always pass and return a single value only. The input should wrap potentially multiple input parameters and the output should convey status as well as provide the result value. You typically have a xxxRequest and a xxxResponse class that wraps the inputs and outputs. Here's what this method might look like:public PostAlbumResponse PostAlbum(PostAlbumRequest request) { var album = request.Album; var userToken = request.UserToken; return new PostAlbumResponse() { IsSuccess = true, Result = String.Format("{0} {1:d} {2}", album.AlbumName, album.Entered,userToken) }; } with these support types:public class PostAlbumRequest { public Album Album { get; set; } public User User { get; set; } public string UserToken { get; set; } } public class PostAlbumResponse { public string Result { get; set; } public bool IsSuccess { get; set; } public string ErrorMessage { get; set; } }   To call this method you now have to assemble these objects on the client and send it up as JSON:var album = { AlbumName: "PowerAge", Entered: "1/1/1977" } var user = { Name: "Rick" } var userToken = "sekkritt"; $.ajax( { url: "samples/PostAlbum", type: "POST", contentType: "application/json", data: JSON.stringify({ Album: album, User: user, UserToken: userToken }), success: function (result) { alert(result.Result); } }); I assemble the individual types first and then combine them in the data: property of the $.ajax() call into the actual object passed to the server, that mimics the structure of PostAlbumRequest server class that has Album, User and UserToken properties. This works well enough but it gets tedious if you have to create Request and Response types for each method signature. If you have common parameters that are always passed (like you always pass an album or usertoken) you might be able to abstract this to use a single object that gets reused for all methods, but this gets confusing too: Overload a single 'parameter' too much and it becomes a nightmare to decipher what your method actual can use. Use JObject to parse multiple Property Values out of an Object If you recall, ASP.NET AJAX and WCF REST used a 'wrapper' object to make default AJAX calls. Rather than directly calling a service you always passed an object which contained properties for each parameter: { parm1: Value, parm2: Value2 } WCF REST/ASP.NET AJAX would then parse this top level property values and map them to the parameters of the endpoint method. This automatic type wrapping functionality is no longer available directly in Web API, but since Web API now uses JSON.NET for it's JSON serializer you can actually simulate that behavior with a little extra code. You can use the JObject class to receive a dynamic JSON result and then using the dynamic cast of JObject to walk through the child objects and even parse them into strongly typed objects. Here's how to do this on the API Controller end:[HttpPost] public string PostAlbum(JObject jsonData) { dynamic json = jsonData; JObject jalbum = json.Album; JObject juser = json.User; string token = json.UserToken; var album = jalbum.ToObject<Album>(); var user = juser.ToObject<User>(); return String.Format("{0} {1} {2}", album.AlbumName, user.Name, token); } This is clearly not as nice as having the parameters passed directly, but it works to allow you to pass multiple parameters and access them using Web API. JObject is JSON.NET's generic object container which sports a nice dynamic interface that allows you to walk through the object's properties using standard 'dot' object syntax. All you have to do is cast the object to dynamic to get access to the property interface of the JSON type. Additionally JObject also allows you to parse JObject instances into strongly typed objects, which enables us here to retrieve the two objects passed as parameters from this jquery code:var album = { AlbumName: "PowerAge", Entered: "1/1/1977" } var user = { Name: "Rick" } var userToken = "sekkritt"; $.ajax( { url: "samples/PostAlbum", type: "POST", contentType: "application/json", data: JSON.stringify({ Album: album, User: user, UserToken: userToken }), success: function (result) { alert(result); } }); Summary ASP.NET Web API brings many new features and many advantages over the older Microsoft AJAX and REST APIs, but realize that some things like passing multiple strongly typed object parameters will work a bit differently. It's not insurmountable, but just knowing what options are available to simulate this behavior is good to know. Now let me say here that it's probably not a good practice to pass a bunch of parameters to an API call. Ideally APIs should be closely factored to accept single parameters or a single content parameter at least along with some identifier parameters that can be passed on the querystring. But saying that doesn't mean that occasionally you don't run into a situation where you have the need to pass several objects to the server and all three of the options I mentioned might have merit in different situations. For now I'm sure the question of how to pass multiple parameters will come up quite a bit from people migrating WCF REST or ASP.NET AJAX code to Web API. At least there are options available to make it work.© Rick Strahl, West Wind Technologies, 2005-2012Posted in Web Api   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

    Read the article

  • Why Java servlet can't get Paypal IPN messages everytime ?

    - by Frank
    I have a Java servlet running on my notebook with Windows Vista, I set up a static IP, did port forwarding and registered for a free DDNS service, now my servlet is running, I gave the url to Paypal to send me IPN messages, I went on to it's sandbox site got to the test tools page, tried to send test messages by clicking the "Send IPN" button, most of the time it would fail, the error is : "IPN delivery failed. Unable to connect to the specified URL. Please verify the URL and try again." But maybe 1 in 10 times, it might be successful and my servlet would get the message, and I looked at the messages I got, they are in correct format. So I called Paypal asking why, he said I shouldn't run the servlet on my notebook, in stead I should run it on the web server, but I told him my ISP doesn't support Java on their server, and since I did all the above steps, shouldn't it be the same to run the servlet on my notebook ? He said his test showed he couldn't get to my servlet, but I asked why maybe 1 in 10 times it could get through ? If there is something wrong with running it on my notebook, then 100% times it should fail, am I correct on this point ? But anyway he said that's all he could do, and I should troubleshoot it myself. The servlet looks like this : import java.io.*; import java.net.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; public class PayPal_Servlet extends HttpServlet { static boolean Debug=true; static String PayPal_Url="https://www.paypal.com/cgi-bin/webscr",Sandbox_Url="https://www.sandbox.paypal.com/cgi-bin/webscr", Dir_License_Messages="C:/Dir_License_Messages/"; static TransparencyExample Transparency_Example; static PayPal_Message_To_License_File_Worker PayPal_message_to_license_file_worker; // Initializes the servlet. public void init(ServletConfig config) throws ServletException { super.init(config); if (!new File(Dir_License_Messages).exists()) new File(Dir_License_Messages).mkdirs(); System.gc(); } /** Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods. * @param request servlet request * @param response servlet response */ protected void processRequest(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { // Read post from PayPal system and add 'cmd' Enumeration en=request.getParameterNames(); String str="cmd=_notify-validate"; while (en.hasMoreElements()) { String paramName=(String)en.nextElement(); String paramValue=request.getParameter(paramName); str=str+"&"+paramName+"="+URLEncoder.encode(paramValue); } // Post back to PayPal system to validate // NOTE: change http: to https: in the following URL to verify using SSL (for increased security). // using HTTPS requires either Java 1.4 or greater, or Java Secure Socket Extension (JSSE) and configured for older versions. URL u=new URL(Debug?Sandbox_Url:PayPal_Url); URLConnection uc=u.openConnection(); uc.setDoOutput(true); uc.setRequestProperty("Content-Type","application/x-www-form-urlencoded"); PrintWriter pw=new PrintWriter(uc.getOutputStream()); pw.println(str); pw.close(); BufferedReader in=new BufferedReader(new InputStreamReader(uc.getInputStream())); String res=in.readLine(); in.close(); // Assign posted variables to local variables String itemName=request.getParameter("item_name"); String itemNumber=request.getParameter("item_number"); String paymentStatus=request.getParameter("payment_status"); String paymentAmount=request.getParameter("mc_gross"); String paymentCurrency=request.getParameter("mc_currency"); String txnId=request.getParameter("txn_id"); String receiverEmail=request.getParameter("receiver_email"); String payerEmail=request.getParameter("payer_email"); if (res.equals("VERIFIED")) // Check notification validation { // check that paymentStatus=Completed // check that txnId has not been previously processed // check that receiverEmail is your Primary PayPal email // check that paymentAmount/paymentCurrency are correct // process payment } else if (res.equals("INVALID")) // Log for investigation { } else // Log for error { } // =========================================================================== if (txnId!=null) { Write_File_Safe_Fast(Dir_License_Messages+txnId+".txt",new StringBuffer(str.replace("&","\n")),false); } // =========================================================================== String Message_File_List[]=Tool_Lib.Get_File_List_From_Dir(Dir_License_Messages); response.setContentType("text/html"); PrintWriter out=response.getWriter(); String title="Reading All Request Parameters",Name="",Value; out.println("<Html><Head><Title>"+title+"</Title></Head>\n<Body Bgcolor=\"#FDF5E6\">\n<H1 Align=Center>"+title+"</H1>\n"+ "<Table Border=1 Align=Center>\n"+"<Tr Bgcolor=\"#FFAD00\"><Th>Parameter Name</Th><Th>Parameter Value(s) Messages = "+Message_File_List.length+"</Th></Tr>"); Enumeration paramNames=request.getParameterNames(); while(paramNames.hasMoreElements()) { String paramName=(String)paramNames.nextElement(); out.print("<Tr><Td>"+paramName+"</Td><Td>"); String[] paramValues=request.getParameterValues(paramName); if (paramValues.length == 1) { String paramValue=paramValues[0]; if (paramValue.length() == 0) out.print("<I>No Value</I>"); else { out.println(paramValue+"</Td></Tr>"); // Out("paramName = "+paramName+" paramValue = "+paramValue); // if (paramName.startsWith("Name")) Name=paramValue; // else if (paramName.startsWith("Value")) Write_File_Safe_Fast("C:/Dir_Data/"+Name,new StringBuffer(paramValue),false); } } else { out.println("<Ul>"); for (int i=0;i<paramValues.length;i++) out.println("<Li>"+paramValues[i]); out.println("</Ul></Td</Tr>"); } } out.println("</Table>\n</Body></Html>"); } /** Handles the HTTP <code>GET</code> method. * @param request servlet request * @param response servlet response */ protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { processRequest(request,response); } /** Handles the HTTP <code>POST</code> method. * @param request servlet request * @param response servlet response */ protected void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { processRequest(request,response); } // Returns a short description of the servlet. public String getServletInfo() { return "Short description"; } // Destroys the servlet. public void destroy() { System.gc(); } public static void Write_File_Safe_Fast(String File_Path,StringBuffer Str_Buf,boolean Append) { FileOutputStream fos=null; BufferedOutputStream bos=null; try { fos=new FileOutputStream(File_Path,Append); bos=new BufferedOutputStream(fos); for (int j=0;j<Str_Buf.length();j++) bos.write(Str_Buf.charAt(j)); } catch (Exception e) { e.printStackTrace(); } finally { try { if (bos!=null) { bos.close(); bos=null; } if (fos!=null) { fos.close(); fos=null; } } catch (Exception ex) { ex.printStackTrace(); } } System.gc(); } } I use Netbean6.7 to develop the servlet, and the code was from Paypal's JSP sample code, what can I do to debug the problem ?

    Read the article

  • Need Help Customizing a Grammar Checking Replace Rule in Java

    - by user567785
    Hello, I am currently adding the Khmer (Cambodian) language to LanguageTool, an opensource grammar checker for OpenOffice (http://www.languagetool.org). I don't know enough Java to customize one of the scripts and wanted to make a request here asking if anyone would be willing to customize it for me (I can put link to your website at http://www.sbbic.org/lang/en-us/volunteer/ if you help). Here is the script that needs customization KhmerWordCoherencyRule.java: /* LanguageTool, a natural language style checker * Copyright (C) 2005 Daniel Naber (http://www.danielnaber.de) * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 * USA */ package de.danielnaber.languagetool.rules.km; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.ResourceBundle; import de.danielnaber.languagetool.AnalyzedSentence; import de.danielnaber.languagetool.AnalyzedToken; import de.danielnaber.languagetool.AnalyzedTokenReadings; import de.danielnaber.languagetool.JLanguageTool; import de.danielnaber.languagetool.tools.StringTools; import de.danielnaber.languagetool.rules.Category; import de.danielnaber.languagetool.rules.RuleMatch; /** * A Khmer rule that matches words or phrases which should not be used and suggests * correct ones instead. Loads the relevant words from * <code>rules/km/coherency.txt</code>, where km is a code of the language. * * @author Andriy Rysin */ public abstract class KhmerWordCoherencyRule extends KhmerRule { private static final String FILE_ENCODING = "utf-8"; private Map<String, String> wrongWords; // e.g. "????? -> "?????" private static final String FILE_NAME = "/km/coherency.txt"; public abstract String getFileName(); public String getEncoding() { return FILE_ENCODING; } /** * Indicates if the rule is case-sensitive. Default value is <code>true</code>. * @return true if the rule is case-sensitive, false otherwise. */ //in Khmer there is no case public boolean isCaseSensitive() { return false; } /** * @return the locale used for case conversion when {@link #isCaseSensitive()} is set to <code>false</code>. */ public Locale getLocale() { return Locale.getDefault(); } public KhmerWordCoherencyRule(final ResourceBundle messages) throws IOException { if (messages != null) { super.setCategory(new Category(messages.getString("category_misc"))); } wrongWords = loadWords(JLanguageTool.getDataBroker().getFromRulesDirAsStream(getFileName())); } public String getId() { return "KM_WORD_COHERENCY"; } public String getDescription() { return "Checks for wrong words/phrases"; } public String getSuggestion() { return " does not match your previous spelling of the word, use "; } public String getShort() { return "Use a consistant spelling throughout"; } public final RuleMatch[] match(final AnalyzedSentence text) { final List<RuleMatch> ruleMatches = new ArrayList<RuleMatch>(); final AnalyzedTokenReadings[] tokens = text.getTokensWithoutWhitespace(); for (int i = 1; i < tokens.length; i++) { final String token = tokens[i].getToken(); final String origToken = token; final String replacement = isCaseSensitive()?wrongWords.get(token):wrongWords.get(token.toLowerCase(getLocale())); if (replacement != null) { final String msg = token + getSuggestion() + replacement; final int pos = tokens[i].getStartPos(); final RuleMatch potentialRuleMatch = new RuleMatch(this, pos, pos + origToken.length(), msg, getShort()); if (!isCaseSensitive() && StringTools.startsWithUppercase(token)) { potentialRuleMatch.setSuggestedReplacement(StringTools.uppercaseFirstChar(replacement)); } else { potentialRuleMatch.setSuggestedReplacement(replacement); } ruleMatches.add(potentialRuleMatch); } } return toRuleMatchArray(ruleMatches); } private Map<String, String> loadWords(final InputStream file) throws IOException { final Map<String, String> map = new HashMap<String, String>(); InputStreamReader isr = null; BufferedReader br = null; try { isr = new InputStreamReader(file, getEncoding()); br = new BufferedReader(isr); String line; while ((line = br.readLine()) != null) { line = line.trim(); if (line.length() < 1) { continue; } if (line.charAt(0) == '#') { // ignore comments continue; } final String[] parts = line.split(";"); if (parts.length != 2) { throw new IOException("Format error in file " + JLanguageTool.getDataBroker().getFromRulesDirAsUrl(getFileName()) + ", line: " + line); } map.put(parts[0], parts[1]); } } finally { if (br != null) { br.close(); } if (isr != null) { isr.close(); } } return map; } public void reset() { } } Here is what I need the SimpleReplaceRule.java to do: 1 - Be able to have more than two spelling variations in the coherency.txt file (right now it can only be Word1;Word2). 2 - Find the first use of ANY of the spelling variations in a document that are found in coherency.txt and then make sure only that spelling is used throughout the document (ex. in the coherency.txt I have Word1;Word2;Word3 then in my document on the first line I write Word2. then on next line I write Word1 and Word 3 - then the grammar checker will flag Word1 and Word3 saying that I should use the spelling "Word2" instead...etc.). If anyone can help I would be grateful! Thanks for your time, Nathan

    Read the article

  • Why does C qicksort function implementation works much slower (tape comparations, tape swapping) than bobble sort function?

    - by Artur Mustafin
    I'm going to implement a toy tape "mainframe" for a students, showing the quickness of "quicksort" class functions (recursive or not, does not really matters, due to the slow hardware, and well known stack reversal techniques) comparatively to the "bubblesort" function class, so, while I'm clear about the hardware implementation ans controllers, i guessed that quicksort function is much faster that other ones in terms of sequence, order and comparation distance (it is much faster to rewind the tape from the middle than from the very end, because of different speed of rewind). Unfortunately, this is not the true, this simple "bubble" code shows great improvements comparatively to the "quicksort" functions in terms of comparison distances, direction and number of comparisons and writes. So I have 3 questions: Does I have mistaken in my implememtation of quicksort function? Does I have mistaken in my implememtation of bubblesoft function? If not, why the "bubblesort" function is works much faster in (comparison and write operations) than "quicksort" function? I already have a "quicksort" function: void quicksort(float *a, long l, long r, const compare_function& compare) { long i=l, j=r, temp, m=(l+r)/2; if (l == r) return; if (l == r-1) { if (compare(a, l, r)) { swap(a, l, r); } return; } if (l < r-1) { while (1) { i = l; j = r; while (i < m && !compare(a, i, m)) i++; while (m < j && !compare(a, m, j)) j--; if (i >= j) { break; } swap(a, i, j); } if (l < m) quicksort(a, l, m, compare); if (m < r) quicksort(a, m, r, compare); return; } } and the kind of my own implememtation of the "bubblesort" function: void bubblesort(float *a, long l, long r, const compare_function& compare) { long i, j, k; if (l == r) { return; } if (l == r-1) { if (compare(a, l, r)) { swap(a, l, r); } return; } if (l < r-1) { while(l < r) { i = l; j = l; while (i < r) { i++; if (!compare(a, j, i)) { continue; } j = i; } if (l < j) { swap(a, l, j); } l++; i = r; k = r; while(l < i) { i--; if (!compare(a, i, k)) { continue; } k = i; } if (k < r) { swap(a, k, r); } r--; } return; } } I have used this sort functions in a test sample code, like this: #include <stdio.h> #include <stdlib.h> #include <math.h> #include <conio.h> long swap_count; long compare_count; typedef long (*compare_function)(float *, long, long ); typedef void (*sort_function)(float *, long , long , const compare_function& ); void init(float *, long ); void print(float *, long ); void sort(float *, long, const sort_function& ); void swap(float *a, long l, long r); long less(float *a, long l, long r); long greater(float *a, long l, long r); void bubblesort(float *, long , long , const compare_function& ); void quicksort(float *, long , long , const compare_function& ); void main() { int n; printf("n="); scanf("%d",&n); printf("\r\n"); long i; float *a = (float *)malloc(n*n*sizeof(float)); sort(a, n, &bubblesort); print(a, n); sort(a, n, &quicksort); print(a, n); free(a); } long less(float *a, long l, long r) { compare_count++; return *(a+l) < *(a+r) ? 1 : 0; } long greater(float *a, long l, long r) { compare_count++; return *(a+l) > *(a+r) ? 1 : 0; } void swap(float *a, long l, long r) { swap_count++; float temp; temp = *(a+l); *(a+l) = *(a+r); *(a+r) = temp; } float tg(float x) { return tan(x); } float ctg(float x) { return 1.0/tan(x); } void init(float *m,long n) { long i,j; for (i = 0; i < n; i++) { for (j=0; j< n; j++) { m[i + j*n] = tg(0.2*(i+1)) + ctg(0.3*(j+1)); } } } void print(float *m, long n) { long i, j; for(i = 0; i < n; i++) { for(j = 0; j < n; j++) { printf(" %5.1f", m[i + j*n]); } printf("\r\n"); } printf("\r\n"); } void sort(float *a, long n, const sort_function& sort) { long i, sort_compare = 0, sort_swap = 0; init(a,n); for(i = 0; i < n*n; i+=n) { if (fmod (i / n, 2) == 0) { compare_count = 0; swap_count = 0; sort(a, i, i+n-1, &less); if (swap_count == 0) { compare_count = 0; sort(a, i, i+n-1, &greater); } sort_compare += compare_count; sort_swap += swap_count; } } printf("compare=%ld\r\n", sort_compare); printf("swap=%ld\r\n", sort_swap); printf("\r\n"); }

    Read the article

  • Tuple in C# 4.0

    - by Jalpesh P. Vadgama
    C# 4.0 language includes a new feature called Tuple. Tuple provides us a way of grouping elements of different data type. That enables us to use it a lots places at practical world like we can store a coordinates of graphs etc. In C# 4.0 we can create Tuple with Create method. This Create method offer 8 overload like following. So you can group maximum 8 data types with a Tuple. Followings are overloads of a data type. Create(T1)- Which represents a tuple of size 1 Create(T1,T2)- Which represents a tuple of size 2 Create(T1,T2,T3) – Which represents a tuple of size 3 Create(T1,T2,T3,T4) – Which represents a tuple of size 4 Create(T1,T2,T3,T4,T5) – Which represents a tuple of size 5 Create(T1,T2,T3,T4,T5,T6) – Which represents a tuple of size 6 Create(T1,T2,T3,T4,T5,T6,T7) – Which represents a tuple of size 7 Create(T1,T2,T3,T4,T5,T6,T7,T8) – Which represents a tuple of size 8 Following are some example code for tuple. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TupleExample { class Program { static void Main(string[] args) { var tuple = System.Tuple.Create<string, string, string>("Jalpesh", "P", "Vadgama"); Console.WriteLine(tuple); var t = System.Tuple.Create<int, string>(1, "Jalpesh"); Console.WriteLine(t); } } } Following is a output of above as expected. You can also access values insides Tuple with ItemN property. Where N represents particular number of item in tuple. Following is an example of it. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TupleExample { class Program { static void Main(string[] args) { var tuple = System.Tuple.Create<string, string, string>("Jalpesh", "P", "Vadgama"); Console.WriteLine(tuple.Item1); Console.WriteLine(tuple.Item2); Console.WriteLine(tuple.Item3); } } } Here you can see I have printed items with Item1,Item2 and Item3 . Following is the output of above code.   Even we can create a nested tuple also following is code for nested tuple. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TupleExample { class Program { static void Main(string[] args) { var tuple = System.Tuple.Create(1,"Jalpesh",new Tuple<string,string>("P","Vadgama")); Console.WriteLine(tuple.Item1); Console.WriteLine(tuple.Item2); Console.WriteLine(tuple.Item3); } } } Following is a output above code as expected. As you can see there are unlimited possibilities we can do lots of things with Tuple. Hope you liked it. Stay tuned for more. Till then Happy Programming!!

    Read the article

  • C# Multiple Property Sort

    - by Ben Griswold
    As you can see in the snippet below, sorting is easy with Linq.  Simply provide your OrderBy criteria and you’re done.  If you want a secondary sort field, add a ThenBy expression to the chain.  Want a third level sort?  Just add ThenBy along with another sort expression. var projects = new List<Project>     {         new Project {Description = "A", ProjectStatusTypeId = 1},         new Project {Description = "B", ProjectStatusTypeId = 3},         new Project {Description = "C", ProjectStatusTypeId = 3},         new Project {Description = "C", ProjectStatusTypeId = 2},         new Project {Description = "E", ProjectStatusTypeId = 1},         new Project {Description = "A", ProjectStatusTypeId = 2},         new Project {Description = "C", ProjectStatusTypeId = 4},         new Project {Description = "A", ProjectStatusTypeId = 3}     };   projects = projects     .OrderBy(x => x.Description)     .ThenBy(x => x.ProjectStatusTypeId)     .ToList();   foreach (var project in projects) {     Console.Out.WriteLine("{0} {1}", project.Description,         project.ProjectStatusTypeId); } Linq offers a great sort solution most of the time, but what if you want or need to do it the old fashioned way? projects.Sort ((x, y) =>         Comparer<String>.Default             .Compare(x.Description, y.Description) != 0 ?         Comparer<String>.Default             .Compare(x.Description, y.Description) :         Comparer<Int32>.Default             .Compare(x.ProjectStatusTypeId, y.ProjectStatusTypeId));   foreach (var project in projects) {     Console.Out.WriteLine("{0} {1}", project.Description,         project.ProjectStatusTypeId); } It’s not that bad, right? Just for fun, let add some additional logic to our sort.  Let’s say we wanted our secondary sort to be based on the name associated with the ProjectStatusTypeId.  projects.Sort((x, y) =>        Comparer<String>.Default             .Compare(x.Description, y.Description) != 0 ?        Comparer<String>.Default             .Compare(x.Description, y.Description) :        Comparer<String>.Default             .Compare(GetProjectStatusTypeName(x.ProjectStatusTypeId),                 GetProjectStatusTypeName(y.ProjectStatusTypeId)));   foreach (var project in projects) {     Console.Out.WriteLine("{0} {1}", project.Description,         GetProjectStatusTypeName(project.ProjectStatusTypeId)); } The comparer will now consider the result of the GetProjectStatusTypeName and order the list accordingly.  Of course, you can take this same approach with Linq as well.

    Read the article

  • Personal Technology – Excel Tip: Comparing Excel Files

    - by Pinal Dave
    This guest post is by Vinod Kumar. Vinod Kumar has worked with SQL Server extensively since joining the industry over a decade ago. Working on various versionsfrom SQL Server 7.0, Oracle 7.3 and other database technologies – he now works with the Microsoft Technology Center (MTC) as a Technology Architect. Let us read the blog post in Vinod’s own voice. I have been writing about Excel Tips over my blog and thought it would be great to share one interesting tips here as a guest blog here. Assume a situation where you want to compare multiple excel files. Here is a typical scenario I have encountered as a common activity. Assume you are sending an Excel file with tons of data, formulae and multiple sheets. Now you are requesting your colleague to validate the file and if required change content for correctness. After receiving the file from your colleague, now you want to know what changes were made by this person to your document. Now here is a cool new addition to Excel 2013 that can help you achieve this task. To get to this option, click the INQUIRE Tab. Incase you don’t have the INQUIRE Tab, check Options using INQUIRE blog. In that post, we discuss all the other options of INQUIRE tab. Once you are on the INQUIRE Tab, select “Compare Files” button as shown in the figure above. This brings a dialog as below. If you are on Windows 8 or Windows 7 OS, search for an application called “Spreadsheet Compare 2013”. Ultimately both the options lead us to the same application. If you are using the stand alone app, once the App initializes, click the “Compare files” options from the toolbar. Make sure to give two different Excel files as shown in the figure above. After selecting the Excel Sheets, you can see the Compare tool has a number of other options to play from. We will talk about some of them later in this post. Just below our toolbar is a colorful side-by-side comparison of both our excel sheets. We can also see the various Tab’s from each file. There is a meaning for each of our color coding which will be discussed next. As you saw above, the color coding has a meaning. For example the bottom pane lists each of the color coding and most importantly each of the changes as compared side-by-side. The detailed information shown below can be exported using the “Export Results” options from the toolbar as a separate Excel Workbook or can be copied to clipboard to be used later. The final piece of the puzzle is to show a graphical view of these differences results based on each category. We cannot drill down per se, but this is a great way to know that the maximum changes seem to be based on “Cell Formats” and then few “Calculated Values” have changed. The INQUIRE option and Spreadsheet Compare 2013 tool is part of Excel 2013. So as you explore using the new version of Excel, there are many such hidden features that are worth exploring. Do let us know if you enjoyed learning a new feature today and I hope you will play around with this feature in your day-today challenges when working with Excel files. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology Tagged: Excel, Personal Technology

    Read the article

  • Default Parameters vs Method Overloading

    - by João Angelo
    With default parameters introduced in C# 4.0 one might be tempted to abandon the old approach of providing method overloads to simulate default parameters. However, you must take in consideration that both techniques are not interchangeable since they show different behaviors in certain scenarios. For me the most relevant difference is that default parameters are a compile time feature while method overloading is a runtime feature. To illustrate these concepts let’s take a look at a complete, although a bit long, example. What you need to retain from the example is that static method Foo uses method overloading while static method Bar uses C# 4.0 default parameters. static void CreateCallerAssembly(string name) { // Caller class - Invokes Example.Foo() and Example.Bar() string callerCode = String.Concat( "using System;", "public class Caller", "{", " public void Print()", " {", " Console.WriteLine(Example.Foo());", " Console.WriteLine(Example.Bar());", " }", "}"); var parameters = new CompilerParameters(new[] { "system.dll", "Common.dll" }, name); new CSharpCodeProvider().CompileAssemblyFromSource(parameters, callerCode); } static void Main() { // Example class - Foo uses overloading while Bar uses C# 4.0 default parameters string exampleCode = String.Concat( "using System;", "public class Example", "{{", " public static string Foo() {{ return Foo(\"{0}\"); }}", " public static string Foo(string key) {{ return \"FOO-\" + key; }}", " public static string Bar(string key = \"{0}\") {{ return \"BAR-\" + key; }}", "}}"); var compiler = new CSharpCodeProvider(); var parameters = new CompilerParameters(new[] { "system.dll" }, "Common.dll"); // Build Common.dll with default value of "V1" compiler.CompileAssemblyFromSource(parameters, String.Format(exampleCode, "V1")); // Caller1 built against Common.dll that uses a default of "V1" CreateCallerAssembly("Caller1.dll"); // Rebuild Common.dll with default value of "V2" compiler.CompileAssemblyFromSource(parameters, String.Format(exampleCode, "V2")); // Caller2 built against Common.dll that uses a default of "V2" CreateCallerAssembly("Caller2.dll"); dynamic caller1 = Assembly.LoadFrom("Caller1.dll").CreateInstance("Caller"); dynamic caller2 = Assembly.LoadFrom("Caller2.dll").CreateInstance("Caller"); Console.WriteLine("Caller1.dll:"); caller1.Print(); Console.WriteLine("Caller2.dll:"); caller2.Print(); } And if you run this code you will get the following output: // Caller1.dll: // FOO-V2 // BAR-V1 // Caller2.dll: // FOO-V2 // BAR-V2 You see that even though Caller1.dll runs against the current Common.dll assembly where method Bar defines a default value of “V2″ the output show us the default value defined at the time Caller1.dll compiled against the first version of Common.dll. This happens because the compiler will copy the current default value to each method call, much in the same way a constant value (const keyword) is copied to a calling assembly and changes to it’s value will only be reflected if you rebuild the calling assembly again. The use of default parameters is also discouraged by Microsoft in public API’s as stated in (CA1026: Default parameters should not be used) code analysis rule.

    Read the article

  • C#, Delegates and LINQ

    - by JustinGreenwood
    One of the topics many junior programmers struggle with is delegates. And today, anonymous delegates and lambda expressions are profuse in .net APIs.  To help some VB programmers adapt to C# and the many equivalent flavors of delegates, I walked through some simple samples to show them the different flavors of delegates. using System; using System.Collections.Generic; using System.Linq; namespace DelegateExample { class Program { public delegate string ProcessStringDelegate(string data); public static string ReverseStringStaticMethod(string data) { return new String(data.Reverse().ToArray()); } static void Main(string[] args) { var stringDelegates = new List<ProcessStringDelegate> { //========================================================== // Declare a new delegate instance and pass the name of the method in new ProcessStringDelegate(ReverseStringStaticMethod), //========================================================== // A shortcut is to just and pass the name of the method in ReverseStringStaticMethod, //========================================================== // You can create an anonymous delegate also delegate (string inputString) //Scramble { var outString = inputString; if (!string.IsNullOrWhiteSpace(inputString)) { var rand = new Random(); var chs = inputString.ToCharArray(); for (int i = 0; i < inputString.Length * 3; i++) { int x = rand.Next(chs.Length), y = rand.Next(chs.Length); char c = chs[x]; chs[x] = chs[y]; chs[y] = c; } outString = new string(chs); } return outString; }, //========================================================== // yet another syntax would be the lambda expression syntax inputString => { // ROT13 var array = inputString.ToCharArray(); for (int i = 0; i < array.Length; i++) { int n = (int)array[i]; n += (n >= 'a' && n <= 'z') ? ((n > 'm') ? 13 : -13) : ((n >= 'A' && n <= 'Z') ? ((n > 'M') ? 13 : -13) : 0); array[i] = (char)n; } return new string(array); } //========================================================== }; // Display the results of the delegate calls var stringToTransform = "Welcome to the jungle!"; System.Console.ForegroundColor = ConsoleColor.Cyan; System.Console.Write("String to Process: "); System.Console.ForegroundColor = ConsoleColor.Yellow; System.Console.WriteLine(stringToTransform); stringDelegates.ForEach(delegatePointer => { System.Console.WriteLine(); System.Console.ForegroundColor = ConsoleColor.Cyan; System.Console.Write("Delegate Method Name: "); System.Console.ForegroundColor = ConsoleColor.Magenta; System.Console.WriteLine(delegatePointer.Method.Name); System.Console.ForegroundColor = ConsoleColor.Cyan; System.Console.Write("Delegate Result: "); System.Console.ForegroundColor = ConsoleColor.White; System.Console.WriteLine(delegatePointer(stringToTransform)); }); System.Console.ReadKey(); } } } The output of the program is below: String to Process: Welcome to the jungle! Delegate Method Name: ReverseStringStaticMethod Delegate Result: !elgnuj eht ot emocleW Delegate Method Name: ReverseStringStaticMethod Delegate Result: !elgnuj eht ot emocleW Delegate Method Name: b__1 Delegate Result: cg ljotWotem!le une eh Delegate Method Name: b__2 Delegate Result: dX_V|`X ?| ?[X ]?{Z_X!

    Read the article

  • Where should instantiated classes be stored?

    - by Eric C.
    I'm having a bit of a design dilemma here. I'm writing a library that consists of a bunch of template classes that are designed to be used as a base for creating content. For example: public class Template { public string Name {get; set;} public string Description {get; set;} public string Attribute1 {get; set;} public string Attribute2 {get; set;} public Template() { //constructor } public void DoSomething() { //does something } ... } The problem is, not only is the library providing the templates, it will also supply quite a few predefined templates which are instances of these template classes. The question is, where do I put these instances of the templates? The three solutions I've come up with so far are: 1) Provide serialized instances of the templates as files. On the one hand, this solution would keep the instances separated from the library itself, which is nice, but it would also potentially add complexity for the user. Even if we provided methods for loading/deserializing the files, they'd still have to deal with a bunch of files, and some kind of config file so the app knows where to look for those files. Plus, creating the template files would probably require a separate app, so if the user wanted to stick with the files method of storing templates, we'd have to provide some kind of app for creating the template files. Also, this requires external dependencies for testing the templates in the user's code. 2) Add readonly instances to the template class Example: public class Template { public string Name {get; set;} public string Description {get; set;} public string Attribute1 {get; set;} public string Attribute2 {get; set;} public Template PredefinedTemplate { get { Template templateInstance = new Template(); templateInstance.Name = "Some Name"; templateInstance.Description = "A description"; ... return templateInstance; } } public Template() { //constructor } public void DoSomething() { //does something } ... } This method would be convenient for users, as they would be able to access the predefined templates in code directly, and would be able to unit test code that used them. The drawback here is that the predefined templates pollute the Template type namespace with a bunch of extra stuff. I suppose I could put the predefined templates in a different namespace to get around this drawback. The only other problem with this approach is that I'd have to basically duplicate all the namespaces in the library in the predefined namespace (e.g. Templates.SubTemplates and Predefined.Templates.SubTemplates) which would be a pain, and would also make refactoring more difficult. 3) Make the templates abstract classes and make the predefined templates inherit from those classes. For example: public abstract class Template { public string Name {get; set;} public string Description {get; set;} public string Attribute1 {get; set;} public string Attribute2 {get; set;} public Template() { //constructor } public void DoSomething() { //does something } ... } and public class PredefinedTemplate : Template { public PredefinedTemplate() { this.Name = "Some Name"; this.Description = "A description"; this.Attribute1 = "Some Value"; ... } } This solution is pretty similar to #2, but it ends up creating a lot of classes that don't really do anything (none of our predefined templates are currently overriding behavior), and don't have any methods, so I'm not sure how good a practice this is. Has anyone else had any experience with something like this? Is there a best practice of some kind, or a different/better approach that I haven't thought of? I'm kind of banging my head against a wall trying to figure out the best way to go. Thanks!

    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 | 247 248 249 250 251 252 253 254 255 256 257 258  | Next Page >