Search Results

Search found 43540 results on 1742 pages for 'method missing'.

Page 403/1742 | < Previous Page | 399 400 401 402 403 404 405 406 407 408 409 410  | Next Page >

  • Passing the Class<T> in java of a generic list?

    - by Rob Stevenson-Leggett
    I have a method for reading JSON from a service, I'm using Gson to do my serialization and have written the following method using type parameters. public T getDeserializedJSON(Class<T> aClass,String url) { Reader r = getJSONDataAsReader(url); Gson gson = new Gson(); return gson.fromJson(r, aClass); } I'm consuming json which returns just an array of a type e.g. [ { "prop":"value" } { "prop":"value" } ] I have a java class which maps to this object let's call it MyClass. However to use my method I need to do this: RestClient<ArrayList<MyClass>> restClient = new RestClient<ArrayList<MyClass>>(); ArrayList<MyClass> results = restClient.getDeserializedJSON(ArrayList<MyClass>.class, url); However, I can't figure out the syntax to do it. Passing just ArrayList.class doesn't work. So is there a way I can get rid of the Class parameter or how do I get the class of the ArrayList of MyClass?

    Read the article

  • Does jQuery have an equivalent to Prototype's Element.identify?

    - by Alan Storm
    Is there a built in method or defacto default plugin that will let you automatically assign an unique ID to an element in jQuery, or do you need to implement something like this yourself? I'm looking for the jQuery equivalent to Prototype's identify method Here's an example. I have some HTML structure on a page that looks like this <span id="prefix_1">foo bar</span> ... <div id="foo"> <span></span> <span></span> <span></span> </div> I want to assign each of the spans an ID that will be unique to the page. So after calling something like this $('#foo span').identify('prefix'); //fake code, no such method The rendered DOM would look something like this <span id="prefix_1">foo bar</span> ... <div id="foo"> <span id="prefix_2"></span> <span id="prefix_3"></span> <span id="prefix_4"></span> </div> Is there anything official-ish/robust for jQuery, or is this something most jQuery developers roll on their own?

    Read the article

  • Recover lost code from compiled apk

    - by AlexRamallo
    I have an issue here..and its making me really nervous. I was working on this game, and it was going great, so I took a copy of it on my laptop to work do some work while away from my computer. long story short, hard-drive failure + poor back ups led to me losing a very important class. Is there a way to decompile the apk to retrieve the bit of code that was lost? It isn't overly complicated or sophisticated, its just that its impossible to re-write it without reading every. single. line. of. code. in the entire application since it initializes a LOT of classes and loads a bunch of stuff in a specific way. With a quick google search I was able to find apktool, which decompiles it into a bunch of .smali files, which I don't think were designed for human reading. All I need to recover is one very big method in the class. I found the smali file that contains it and I think I found the line where it starts. something like .method public declared-synchronized load(Lcom/X/X/game/X;)I Anyone help would be appreciated since I would have to scrap the entire game without this method.

    Read the article

  • Common methods/implementation across multiple WCF Services

    - by Rob
    I'm looking at implementing some WCF Services as part of an API for 3rd parties to access data within a product I work on. There are currently a set of services exposed as "classic" .net Web Services and I need to emulate the behaviour of these, at least in part. The existing services all have an AcquireAuthenticationToken method that takes a set of parameters (username, password, etc) and return a session token (represented as a GUID), which is then passed in on calls to any other method (There's also a ReleaseAuthenticationToken method, no guesses needed as to what that does!). What I want to do is implement multiple WCF services, such as: ProductData UserData and have both of these services share a common implementation of Acquire/Release. From the base project that is created by VS2k8, it would appear I will start with, per service: public class ServiceName : IServiceName { } public interface IServiceName { } Therefore my questions would be: Will WCF tolerate me adding a base class to this, public class ServiceName : ServiceBase, IServiceName, or does the fact that there's an interface involved mean that won't work? If "No it won't work" to Question 1, could I change IServiceName so it extends another interface, IServiceBase, thus forcing the presence of Acquire/Release methods, but then having to supply the implementation in each service. Are 1 and 2 both really bad ideas and there's actually a much better solution that, knowing next to nothing about WCF, I just haven't thought of?

    Read the article

  • My partial is not where rails expects it to be (nested partials)

    - by new2ruby
    I have a model Submissions which has many Performers. I have a partial for showing an individual submissions (app/views/submissions/_submission.html.erb): <div> Show stuff relating to @submission ... <%= render @performers %> </div> and a partial for showing performers (app/views/performers/_performer.html.erb): <%= div_for performer do %> <%= performer.name %> <% end %> This works fine from (app/views/submissions/show.html.erb): <%= render @submission %> But I want to use this from a different namespace too (app/views/curator/submissions/show.html.erb). But I get this error: Missing partial curator/submissions/submission with {:locale=>[:en], :formats=>[:html], :handlers=>[:erb, :builder, :coffee]}. Searched in: * "/Users/ircmullaney/RubyCode/cif/app/views" * "/Users/ircmullaney/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/devise-2.1.2/app/views" I can fix this by changing the render to this: <%= render 'submissions/submission' %> But, then the nested partial fails: Missing partial curator/performers/performer with {:locale=>[:en], :formats=>[:html], :handlers=>[:erb, :builder, :coffee]}. Searched in: * "/Users/ircmullaney/RubyCode/cif/app/views" * "/Users/ircmullaney/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/devise-2.1.2/app/views" This doesn't work: <%= render 'performers/performer' %> because of the div_for: undefined method `model_name' for NilClass:Class Any ideas how I should do this?

    Read the article

  • Matching Class arrays

    - by frinkz
    I'm writing a routine to invoke methods, found by a name and an array of parameter Class values Matching the Method by getName works, but when trying to match the given Class[] for parameters, and Method.getParameterTypes(), I'm having trouble. I assumed that this would work: Class[] searchParams = new Class[] { float.class, String.class }; Class[] methodParams = m.getParameterTypes(); if(methodParams == searchParams) { m.invoke(this, paramValues); } But apparantly not - m.invoke is never reached. I've checked, and methodParams gives the same classes as searchParams. The code below works, and picks the right method, but it seems like a very dirty way of doing things, I'm sure I'm missing something obvious. Class[] searchParams = new Class[] { float.class, String.class }; Class[] methodParams = m.getParameterTypes(); boolean isMatch = true; for(int i = 0; i < searchParams.length; i++) { if(!searchParams.getClass().equals(methodParams.getClass())) { isMatch = false; } } if(isMatch) { m.invoke(this, paramValues); }

    Read the article

  • Basic user authentication with records in AngularFire

    - by ajkochanowicz
    Having spent literally days trying the different, various recommended ways to do this, I've landed on what I think is the most simple and promising. Also thanks to the kind gents from this SO question: Get the index ID of an item in Firebase AngularFire Curent setup Users can log in with email and social networks, so when they create a record, it saves the userId as a sort of foreign key. Good so far. But I want to create a rule so twitter2934392 cannot read facebook63203497's records. Off to the security panel Match the IDs on the backend Unfortunately, the docs are inconsistent with the method from is firebase user id unique per provider (facebook, twitter, password) which suggest appending the social network to the ID. The docs expect you to create a different rule for each of the login method's ids. Why anyone using 1 login method would want to do that is beyond me. (From: https://www.firebase.com/docs/security/rule-expressions/auth.html) So I'll try to match the concatenated auth.provider with auth.id to the record in userId for the respective registry item. According to the API, this should be as easy as In my case using $registry instead of $user of course. { "rules": { ".read": true, ".write": true, "registry": { "$registry": { ".read": "$registry == auth.id" } } } } But that won't work, because (see the first image above), AngularFire sets each record under an index value. In the image above, it's 0. Here's where things get complicated. Also, I can't test anything in the simulator, as I cannot edit {some: 'json'} To even authenticate. The input box rejects any input. My best guess is the following. { "rules": { ".write": true, "registry": { "$registry": { ".read": "data.child('userId').val() == (auth.provider + auth.id)" } } } } Which both throws authentication errors and simultaneously grants full read access to all users. I'm losing my mind. What am I supposed to do here?

    Read the article

  • Minimizing server load in case of many XMLHttpRequest calls

    - by user1888975
    I am making a website where users are to like some articles. Whenever the like button is clicked I am sending a XMLHttpRequest to the server to run a file called like_clicked.php along with the get data of article id and user id. This file takes article id and user id and updates the sql database and also adds a node in an xml file related to the user. This is the first time I am doing something for mass usage. I am worried about the server load when too many users call the like_clicked.php file. Please help me, if this method is ok. I am also thinking of an alternative in case the above method fails. I am thinking of making many like_clicked files (namely like_clicked1.php, like_clicked2.php ... ) to minimize load on a single i-node. Is there a method to detect that it is better to call the next like_clicked file. Here we would need to detect how many calls per unit time are coming for the particular file. How do we handle this? Thanks in advance.

    Read the article

  • NSString , EXC_BAD_ACCESS and stringByAppendingString

    - by amnon
    Hi, i wrote the following code : NSString *table = [[NSString alloc]initWithString:@"<table>"] ; for (NSDictionary *row in rows) { table = [table stringByAppendingString:@"<tr>"]; NSArray *cells = [row objectForKey:@"cells"]; for (NSString *cell in cells){ table = [table stringByAppendingString:@"<td>"]; table = [table stringByAppendingString:cell]; table = [table stringByAppendingString:@"</td>"]; } table = [table stringByAppendingString:@"</tr>"]; index++; } table = [table stringByAppendingString:@"</table>"]; return [table autorelease]; the rows are json response parsed by jsonlib this string is returned to a viewcontroller that loads it into a webview ,but i keep getting exc_bad_access for this code on completion of the method that calls it , i don't even have to load it to the webview just calling this method and not using the nsstring causes the error on completion of the calling method... any help will be apperciated thanks .

    Read the article

  • displaying a WPF Window from a System.Configuration.Install.Installer class

    - by cbeuker
    Greetings all, I have a question. I have created a WPF application. So, I naturally created an installer (Visual Studio Install project) for it. In the Commit section of the installer I want to launch a WPF window which is my configuration wizard. So I created a Installer class, overrode the Commit method and put the following in method: Application theApp = new Application; theApp.Run (new MyWPFWizardWindow()); I keep getting the error: The calling thread must be STA, because many UI components require this. No problems, this makes as it is a GUI application. But I can't, for the life of me, get the installer to fire up my window. I have tried putting [STAThread] on the method. I have tried firing up a thread and setting the ApartmentState to STA. I am guessing it's something really simple that I am over looking. Anyone have any thoughts? Thanks in advance.. cmb..

    Read the article

  • Function returning pointer to struct

    - by GammaGuy
    I am having some issues with code that is returning a pointer to a struct declared inside a class. Here is my code so far: SortedList.h #ifndef SORTEDLIST_H #define SORTEDLIST_H class SortedList{ public: SortedList(); ... private: struct Listnode { Student *student; Listnode *next; }; static Listnode *copyList (Listnode *L); }; #endif SortedList.cpp #include "SortedList.h" ... // Here is where the problem lies Listnode SortedList::*copyList(Listnode *L) { return 0; // for NULL } Apparently, the copy list method wont compile. I am using Microsoft Visual Studio and the compiler tells me that "Listnode" is unidentified. When I try to compile, here is whhat I get: 1>------ Build started: Project: Program3, Configuration: Debug Win32 ------ 1> SortedList.cpp 1>c:\users\owner\documents\college\fall 2012\cs 368 - learn c++\program3\program3\sortedlist.cpp(159): error C2657: 'SortedList::*' found at the start of a statement (did you forget to specify a type?) 1>c:\users\owner\documents\college\fall 2012\cs 368 - learn c++\program3\program3\sortedlist.cpp(159): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\users\owner\documents\college\fall 2012\cs 368 - learn c++\program3\program3\sortedlist.cpp(159): error C2065: 'L' : undeclared identifier 1>c:\users\owner\documents\college\fall 2012\cs 368 - learn c++\program3\program3\sortedlist.cpp(159): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\users\owner\documents\college\fall 2012\cs 368 - learn c++\program3\program3\sortedlist.cpp(159): fatal error C1903: unable to recover from previous error(s); stopping compilation ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== Help would be greatly appreciated...ASAP

    Read the article

  • How can I get 100% test coverage in a Perl module that uses DBI?

    - by BrianH
    I am a bit new to the Devel::Cover module, but have found it very useful in making sure I am not missing tests. A problem I am running into is understanding the report from Devel::Cover. I've looked at the documentation, but can't figure out what I need to test to get 100% coverage. Here is the output from the cover report: line err stmt bran cond sub pod time code ... 36 sub connect_database { 37 3 3 1 1126 my $self = shift; 38 3 100 24 if ( !$self->{dsn} ) { 39 1 7 croak 'dsn not supplied - cannot connect'; 40 } 41 *** 2 33 21 $self->{dbh} = DBI->connect( $self->{dsn}, q{}, q{} ) 42 || croak "$DBI::errstr"; 43 1 11 return $self; 44 } ... line err % l !l&&r !l&&!r expr ----- --- ------ ------ ------ ------ ---- 41 *** 33 1 0 0 'DBI'->connect($$self{'dsn'}, '', '') || croak("$DBI::errstr") And here is and example of my code that tests this specific line: my $database = MyModule::Database->new( { dsn => 'Invalid DSN' }); throws_ok( sub { $database->connect_database() }, qr/Can't connect to data source/, 'Test connection exception (invalid dsn)' ); This test passes - the connect does throw an error and fulfills my "throws_ok" test. I do have some tests that test for a successful connection, which is why I think I have 33% coverage, but if I'm reading it correctly, cover thinks I am not testing the "|| croak" part of the statement. I thought I was, with the "throws_ok" test, but obviously I am missing something. Does anyone have advice on how I can test my DBI-connect line successfully? Thanks!

    Read the article

  • Visual studio 2008 unit test keeps failing

    - by Gerbrand
    I've create a method that calculates the harmonic mean based on a list of doubles. But when I'm running the test it keeps failing even thou the output result are the same. My harmonic mean method: public static double GetHarmonicMean(List<double> parameters) { var cumReciprocal = 0.0d; var countN = parameters.Count; foreach( var param in parameters) { cumReciprocal += 1.0d/param; } return 1.0d/(cumReciprocal/countN); } My test method: [TestMethod()] public void GetHarmonicMeanTest() { var parameters = new List<double> { 1.5d, 2.3d, 2.9d, 1.9d, 5.6d }; const double expected = 2.32432293165495; var actual = OwnFunctions.GetHarmonicMean(parameters); Assert.AreEqual(expected, actual); } After running the test the following message is showing: Assert.AreEqual failed. Expected:<2.32432293165495. Actual:<2.32432293165495. For me that are both the same values. Can somebody explain this? Or am I doing something wrong?

    Read the article

  • Load Empty Database table

    - by john White
    I am using SQLexpress and VS2008. I have a DB with a table named "A", which has an IdentitySpecification column named ID. The ID is auto-incremented. Even if the row is deleted, the ID still increases. After several data manipulation, the current ID has reached 15, for example. When I run the application if there's at least 1 row: if I add a new row, the new ID is 16. Everything is fine. If the table is empty (no row): if I add a new row, the new ID is 0, which is an error (I think). And further data manipulation (eg. delete or update) will result in an unhandled exception. Has anyone encountered this? PS. In my table definition, the ID has been selected as follow: Identity Increment = 1; Identity Seed =1; The DB load code is: dataSet = gcnew DataSet(); dataAdapter->Fill(dataSet,"A"); dataTable=dataSet->Tables["A"]; dbConnection->Open(); The Update button method dataAdapter->Update(dataSet,"tblInFlow"); dataSet->AcceptChanges(); dataTable=dataSet->Tables["tblInFlow"]; dataGrid->DataSource=dataTable; If I press Update: if there's at least a row: the datagrid view updates and shows the table correctly. if there's nothing in the table (no data row), the Add method will add a new row, but from ID 0. If I close the program and restart it again: the ID would be 16, which is correct. This is the add method row=dataTable->NewRow(); row["column1"]="something"; dataTable->Rows->Add(row); dataAdapter->Update(dataSet,"A"); dataSet->AcceptChanges(); dataTable=dataSet->Tables["A"];

    Read the article

  • Spring Controller redirect to another page

    - by user1386375
    Hey I got the following problem. This is the content of the jspx file: function postSMTH() { $.ajax({ type: "POST", url: document.getElementById("urltxt").value, data: parameters, }); } <input type="hidden" value="${pageContext.request.contextPath}/foo/foo2/foodat" name="urltxt" id="urltxt"/> <div class="foodat"><a href="javascript:postSMTH();"><spring:message code="foo_foo2_foodat_text" text="FOODAT"/></a></div> So if I push the submit button, the postSMTH function is called and the ajax object is paste to the Controller which look like this: @Controller @RequestMapping(value="/foo") public class FooController { .............. @RequestMapping(value="/foo2", method=RequestMethod.POST) public String homePOST(HttpServletRequest request) { ........ } @RequestMapping(value="/foo2", method=RequestMethod.GET) public String homeGET(HttpServletRequest request) { ........ } @RequestMapping(value="/foo2/foodat", method=RequestMethod.POST) public String doTHAT(HttpServletRequest request) { // check authorization Map fooMap = request.getParameterMap(); // do something in the Database, depending on the paramMap return "redirect:/foo/foo1"; } } Everything is working fine regarding the Database, but the Problem is, that the redirect at the end DOESN'T work. It just stays at the page foo2. I'm new to Spring, maybe its a little mistake somewhere. I just cant make it out by myself. Would be nice if someone would have some hint. Thanks

    Read the article

  • Prolog Beginner: How to unify with arithmentic cmparison operators or how to get a set var to range

    - by sixtyfootersdude
    I am new to prolog. I need to write an integer adder that will add numbers between 0-9 to other numbers 0-9 and produce a solution 0-18. This is what I want to do: add(in1, in2, out) :- in1 < 10, in2 < 10, out < 18. I would like to be able to call it like this: To Check if it is a valid addition: ?- add(1,2,3). true ?- add(1,2,4). false With one missing variable: ?- add(X,2,3). 1 ?- add(1,4,X). 5 With multiple missing variables: ?-add(X,Y,Z). % Some output that would make sense. Some examples could be: X=1, Y=1, Z=2 ; X=2, Y=1, Z=3 ...... I realize that this is probably a pretty simplistic question and it is probably very straightforward. However cording to the prolog tutorial I am using: "Unlike unification Arithmetic Comparison Operators operators cannot be used to give values to a variable. The can only be evaluated when every term on each side have been instantiated."

    Read the article

  • Android: How to declare global variables?

    - by niko
    Hi, I am creating an application which requires login. I created the main and the login activity. In the main activity onCreate method I added the following condition: public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); ... loadSettings(); if(strSessionString == null) { login(); } ... } The onActivityResult method which is executed when the login form terminates looks like this: @Override public void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); switch(requestCode) { case(SHOW_SUBACTICITY_LOGIN): { if(resultCode == Activity.RESULT_OK) { strSessionString = data.getStringExtra(Login.SESSIONSTRING); connectionAvailable = true; strUsername = data.getStringExtra(Login.USERNAME); } } } The problem is the login form sometimes appears twice (the login() method is called twice) and also when the phone keyboard slides the login form appears again and I guess the problem is the variable strSessionString. Does anyone know how to set the variable global in order to avoid login form appearing after the user already successfully authenticates? Thanks!

    Read the article

  • Sharepoint page menu items gone?

    - by Richard
    I'm running MOSS 2007 and have created a new site under an existing one using sitemanager.aspx. I've done this on two machines. on one of those everything works correctly, while on the other some of the menu items for pages in the site seem to be gone. Also on the faulty site I get "Access denied" when I click "Version history". The permissions on both sites should be the same. I attach a screenshot of how the menus differ from each other. The one to the right (the faulty one) is unfortunately not in English but the items appearing on it are "Open link in a new window", "Copy", "Edit page settings" and "Version history". "View properties" and some more items are missing! What could have caused this? Screenshot: I'm running MOSS 2007 and have created a new site under an existing one using sitemanager.aspx. I've done this on two machines. on one of those everything works correctly, while on the other some of the menu items for pages in the site seem to be gone. Also on the faulty site I get "Access denied" when I click "Version history". The permissions on both sites should be the same. I attach a screenshot of how the menus differ from each other. The one to the right (the faulty one) is unfortunately not in English but the items appearing on it are "Open link in a new window", "Copy", "Edit page settings" and "Version history". "View properties" and some more items are missing! What could have caused this? Screenshot: hxxp://i40.tinypic.com/302naxx.jpg

    Read the article

  • Encode_JSON Errors in Lasso 8.6.2 After Period of Time

    - by ATP_JD
    We are in the process of converting apps from Lasso 8 to Lasso 9, and as an intermediate step, have upgraded from 8.5.5 to 8.6.2 (which runs alongside 9 on our new box, in different virtual hosts). I am finding that with 8.6.2 we are getting a slew of errors on pages that call encode_json. The weird thing with these errors is that they don't start happening until some period of time after the site starts. Then, some hours later, all encode_json calls begin to fail with error messages like this: An error occurred while processing your request. Error Information Error Message: No tag, type or constant was defined under the name "?????????????????" with arguments: array: (pair: (-find)=([\x{0020}-\x{21}\x{23}-\x{5b}\x{5d}-\x{10fff}])), (r) at: onCompare with params: 'r' at: JSON with params: 'reload', -Options=array: (-Internal) at: JSON with params: @map: (reload)=(false), (tcstring)=(LZU), (timestring)=(10:42 AM&nbsp;&nbsp;&nbsp;1442Z) at: [...].lasso with params: 'pageloadtime'='1383038310' on line: 31 at position: 1 Error Code: -9948 (Yes, those Chinese(?) characters are in the error message.) I have removed the 8.5.5 encode_json tag from LassoStartup, so we are using the correct built-in method. The encode_json method fails for any and all parameters I throw at it from simple strings to arrays of maps. Upon restarting the site, encode_json resumes working for an hour or two, seemingly depending on load. On 8.5.5, we don't have this problem. Does anyone have experience with this issue? Any advice regarding trying the 8.5.5 tag swap encode_json to see if I can override the built-in method? Maybe it will work better? Thanks in advance for your time and assistance. -Justin

    Read the article

  • Design pattern for loading multiple message types

    - by lukem00
    As I was looking through SO I came across a question about handling multiple message types. My concern is - how do I load such a message in a neat way? I decided to have a separate class with a method which loads one message each time it's invoked. This method should create a new instance of a concrete message type (say AlphaMessage, BetaMessage, GammaMessage, etc.) and return it as a Message. class MessageLoader { public Message Load() { // ... } } The code inside the method is something which looks really awful to me and I would very much like to refactor it/get rid of it: Message msg = Message.Load(...); // load yourself from whatever source if (msg.Type == MessageType.Alpha) return new AlphaMessage(msg); if (msg.Type == MessageType.Beta) return new BetaMessage(msg); // ... In fact, if the whole design looks just too messy and you guys have a better solution, I'm ready to restructure the whole thing. If my description is too chaotic, please let me know what it's missing and I shall edit the question. Thank you all.

    Read the article

  • Mono Develop 2.4.1 + linq error.

    - by Nev_Rahd
    I just started to learn Mono Develop Installed Mono Develop 2.4.1 and trial version of Mono Touch. my Code: using System; using System.Xml.Linq; using System.Collections.Generic; namespace RSSReader { public static class RSSRepository { public static IList<FeedItem> GetFeeds(string url) { XDocument rssFeed = XDocument.Load(url); Console.Write(rssFeed.ToString()); var feeds = new List<FeedItem>(); try { var query = from item in rssFeed.Descendants("item") select new FeedItem { Title = item.Element("title").Value, Published = DateTime.Parse(item.Element("pubDate").Value), Url = item.Element("link").Value }; feeds = query.ToList(); } catch (Exception ex){ Console.WriteLine(ex.Message); } return feeds; } } } This is throwing an error: An implementation of 'select' query expression pattern could not be found. Are you missing 'System.linq' using directive or 'System.Core.dll' assembly reference? I got both references to System.Xml.Linq and System.Core What am i missing ?

    Read the article

  • Extensions methods and forward compatibilty of source code.

    - by TcKs
    Hi, I would like solve the problem (now hypothetical but propably real in future) of using extension methods and maginification of class interface in future development. Example: /* the code written in 17. March 2010 */ public class MySpecialList : IList<MySpecialClass> { // ... implementation } // ... somewhere elsewhere ... MySpecialList list = GetMySpecialList(); // returns list of special classes var reversedList = list.Reverse().ToList(); // .Reverse() is extension method /* now the "list" is unchanged and "reveresedList" has same items in reversed order */ /* --- in future the interface of MySpecialList will be changed because of reason XYZ*/ /* the code written in some future */ public class MySpecialList : IList<MySpecialClass> { // ... implementation public MySpecialList Reverse() { // reverse order of items in this collection return this; } } // ... somewhere elsewhere ... MySpecialList list = GetMySpecialList(); // returns list of special classes var reversedList = list.Reverse().ToList(); // .Reverse() was extension method but now is instance method and do something else ! /* now the "list" is reversed order of items and "reveresedList" has same items lake in "list" */ My question is: Is there some way how to prevent this case (I didn't find them)? If is now way how to prevent it, is there some way how to find possible issues like this? If is now way how to find possible issues, should I forbid usage of extension methods? Thanks.

    Read the article

  • How do I form a Rails link_to with custom field value as parameter

    - by rwheadon
    I have an invoice form where I'm giving the user opportunity to apply coupons to the invoice total. These coupons are held in another Model and I am going to do a lookup on the Coupon code (something like "20OFFONFRIDAY") which I will use to find what the restrictions and benefits of the coupon. (and to see if it even exists at all) The invoice does not have "coupon_code" on it so I hand forged the field onto my form with html: <% if (@invoice.status == 'new') %> <input id="coupon_code" name="coupon_code" type="text"/> <% end %> and I am calling a controller method with link_to and would like something like the following jquery enhanced link_to to work: <%= link_to "Apply Coupon", { :controller=>"invoices", :id=>@invoice.id, :coupon_code=>$('.coupon_code').val(), :action=>"apply_coupon_code" }, :method=>"post" %> ^formatted for easier reading Then inside my "apply_coupon_code" method I will go off to a couple other models and perform business logic before returning the updated invoice page. ...but maybe it's a pipe dream. I guess if push came to shove I could add the "coupon_code" field to my invoice model (even though it's persisted elsewhere.) so it's part of the entity and thus easily available on my form to send back into a controller, but I just hate adding a column to make a coupon validation easier. I figured I'd ping stackoverflow before taking that path.

    Read the article

  • C++: Vector of objects vs. vector of pointers to new objects?

    - by metamemetics
    Hello, I am seeking to improve my C++ skills by writing a sample software renderer. It takes objects consisting of points in a 3d space and maps them to a 2d viewport and draws circles of varying size for each point in view. Which is better: class World{ vector<ObjectBaseClass> object_list; public: void generate(){ object_list.clear(); object_list.push_back(DerivedClass1()); object_list.push_back(DerivedClass2()); or... class World{ vector<ObjectBaseClass*> object_list; public: void generate(){ object_list.clear(); object_list.push_back(new DerivedClass1()); object_list.push_back(new DerivedClass2()); ?? Would be using pointers in the 2nd example to create new objects defeat the point of using vectors, because vectors automatically call the DerivedClass destructors in the first example but not in the 2nd? Are pointers to new objects necessary when using vectors because they handle memory management themselves as long as you use their access methods? Now let's say I have another method in world: void drawfrom(Viewport& view){ for (unsigned int i=0;i<object_list.size();++i){ object_list.at(i).draw(view); } } When called this will run the draw method for every object in the world list. Let's say I want derived classes to be able to have their own versions of draw(). Would the list need to be of pointers then in order to use the method selector (-) ?

    Read the article

  • Writing a generic function that can take a Writer as well as an OutputStream

    - by ebruchez
    I wrote a couple of functions that look like this: def myWrite(os: OutputStream) = {} def myWrite(w: Writer) = {} Now both are very similar and I thought I would try to write a single parametrized version of the function. I started with a type with the two methods that are common in the Java OutputStream and Writer: type Writable[T] = { def close() : Unit def write(cbuf: Array[T], off: Int, len: Int): Unit } One issue is that OutputStream writes Byte and Writer writes Char, so I parametrized the type with T. Then I write my function: def myWrite[T, A[T] <: Writable[T]](out: A[T]) = {} and try to use it: val w = new java.io.StringWriter() myWrite(w) Result: <console>:9: error: type mismatch; found : java.io.StringWriter required: ?A[ ?T ] Note that implicit conversions are not applicable because they are ambiguous: both method any2ArrowAssoc in object Predef of type [A](x: A)ArrowAssoc[A] and method any2Ensuring in object Predef of type [A](x: A)Ensuring[A] are possible conversion functions from java.io.StringWriter to ?A[ ?T ] myWrite(w) I tried a few other combinations of types and parameters, to no avail so far. My question is whether there is a way of achieving this at all, and if so how. (Note that the implementation of myWrite will need, internally, to know the type T that parametrizes the write() method, because it needs to create a buffer as in new ArrayT.)

    Read the article

< Previous Page | 399 400 401 402 403 404 405 406 407 408 409 410  | Next Page >