Search Results

Search found 34668 results on 1387 pages for 'return'.

Page 549/1387 | < Previous Page | 545 546 547 548 549 550 551 552 553 554 555 556  | Next Page >

  • pass Value from class to JFrame

    - by MYE
    Hello everybody! i have problem between pass value from Class to another JFrame my code write follow MVC Model. Therefore i have 1 class is controller , one jframe is view and 1 class is model. i have some handle process on controller to get value on it and i want this value to jframe but not pass by constructor . How can i pass value from class to jframe and when value be pass jframe will use it to handle. Ex: public class A{ private String str; public A(){ } public void handle(){ ViewFrame v = new ViewFrame(); v.setVisible(true); v.pack(). v.setSize(330,600); str = "Hello World"; //init value here v.getString(str);// pass value to jframe here. } } ======================= public class ViewFrame extends JFrame{ private String str; public ViewFrame (){ System.out.println(str); } public String getString(String str){ return this.str = str; } } but it return null??

    Read the article

  • C macro issue: redefinition of functions / structure

    - by Andrei Ciobanu
    Given the following code (it's a macro that generates code for a list data structure, based on the contained type). list.h #ifndef _LIST_H #define _LIST_H #ifdef __cplusplus extern "C" { #endif #define LIST_TEMPLATE_INIT(type) \ typedef struct __list_s_##type { \ struct __list_s_##type *next; \ type value; \ } __list_##type; \ \ __list_##type * __list_##type##_malloc(type value){ \ __list_##type * list = NULL; \ list = malloc(sizeof(*list)); \ list->value = value; \ return list; \ }\ \ void __list_##type##_free(__list_##type *list){\ __list_##type * back = list;\ while(list=list->next){\ free(back);\ back = list;\ }\ } #define LIST_TYPE(type) __list_##type #define LIST_MALLOC(type,value) __list_##type##_malloc(value) #define LIST_FREE(type,list) __list_##type##_free(list) #define LIST_DATA(list) (list->value) #ifdef __cplusplus } #endif #endif /* _LIST_H */ And here is how the above code works: #include <stdio.h> #include <stdlib.h> #include "list.h" /* * */ LIST_TEMPLATE_INIT(int) int main(int argc, char** argv) { LIST_TYPE(int)* list = NULL; list = LIST_MALLOC(int, 5); printf("%d",LIST_DATA(list)); LIST_FREE(int,list); return (0); } My question, is it possible to somehow be able to call : LIST_TEMPLATE_INIT(int), as many times as I want, in a decentralized fashion ? The current issue with this right now is that calling LIST_TEMPLATE_INIT(int) in another file raise compilation errors (because of function redefinition): Example of error: error: redefinition of ‘struct __list_s_int’

    Read the article

  • Dynamic Array of Objects Sans Vector Class

    - by Connor Black
    I am doing a homework assignment for my summer OO class and we need to write two classes. One is called Sale and the other is called Register. I've written my Sale class; here's the .h file: enum ItemType {BOOK, DVD, SOFTWARE, CREDIT}; class Sale { public: Sale(); // default constructor, // sets numerical member data to 0 void MakeSale(ItemType x, double amt); ItemType Item(); // Returns the type of item in the sale double Price(); // Returns the price of the sale double Tax(); // Returns the amount of tax on the sale double Total(); // Returns the total price of the sale void Display(); // outputs sale info private: double price; // price of item or amount of credit double tax; // amount of sales tax double total; // final price once tax is added in. ItemType item; // transaction type }; For the Register class we need to include a dynamic array of Sale objects in our member data. We cannot use the vector class. How is this done? Here's my 'Register' '.h' class Register{ public: Register(int ident, int amount); ~Register(); int GetID(){return identification;} int GetAmount(){return amountMoney;} void RingUpSale(ItemType item, int basePrice); void ShowLast(); void ShowAll(); void Cancel(); int SalesTax(int n); private: int identification; int amountMoney; };

    Read the article

  • iPhone AES encryption issue

    - by Dilshan
    Hi, I use following code to encrypt using AES. - (NSData*)AES256EncryptWithKey:(NSString*)key theMsg:(NSData *)myMessage { // 'key' should be 32 bytes for AES256, will be null-padded otherwise char keyPtr[kCCKeySizeAES256 + 1]; // room for terminator (unused) bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding) // fetch key data [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding]; NSUInteger dataLength = [myMessage length]; //See the doc: For block ciphers, the output size will always be less than or //equal to the input size plus the size of one block. //That's why we need to add the size of one block here size_t bufferSize = dataLength + kCCBlockSizeAES128; void* buffer = malloc(bufferSize); size_t numBytesEncrypted = 0; CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding, keyPtr, kCCKeySizeAES256, NULL /* initialization vector (optional) */, [myMessage bytes], dataLength, /* input */ buffer, bufferSize, /* output */ &numBytesEncrypted); if (cryptStatus == kCCSuccess) { //the returned NSData takes ownership of the buffer and will free it on deallocation return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted]; } free(buffer); //free the buffer; return nil; } However the following code chunk returns null if I tried to print the encryptmessage variable. Same thing applies to decryption as well. What am I doing wrong here? NSData *encrData = [self AES256EncryptWithKey:theKey theMsg:myMessage]; NSString *encryptmessage = [[NSString alloc] initWithData:encrData encoding:NSUTF8StringEncoding]; Thank you

    Read the article

  • Is there a way to receive data as unsigned char over UDP on Qt?

    - by user269037
    I need to send floating point numbers using a UDP connection to a Qt application. Now in Qt the only function available is qint64 readDatagram ( char * data, qint64 maxSize, QHostAddress * address = 0, quint16 * port = 0 ) which accepts data in the form of signed character buffer. I can convert my float into a string and send it but it will obviously not be very efficient converting a 4 byte float into a much longer sized character buffer. I got hold of these 2 functions to convert a 4 byte float into an unsinged 32 bit integer to transfer over network which works fine for a simple C++ UDP program but for Qt I need to receive the data as unsigned char. Is it possible to avoid converting the floatinf point data into a string and then sending it? uint32_t htonf(float f) { uint32_t p; uint32_t sign; if (f < 0) { sign = 1; f = -f; } else { sign = 0; } p = ((((uint32_t)f)&0x7fff)<<16) | (sign<<31); // Whole part and sign. p |= (uint32_t)(((f - (int)f) * 65536.0f))&0xffff; // Fraction. return p; } float ntohf(uint32_t p) { float f = ((p>>16)&0x7fff); // Whole part. f += (p&0xffff) / 65536.0f; // Fraction. if (((p>>31)&0x1) == 0x1) { f = -f; } // Sign bit set. return f; }

    Read the article

  • Mapping many-to-many association table with extra column(s)

    - by user635524
    My database contains 3 tables: User and Service entities have many-to-many relationship and are joined with the SERVICE_USER table as follows: USERS - SERVICE_USER - SERVICES SERVICE_USER table contains additional BLOCKED column. What is the best way to perform such a mapping? These are my Entity classes @Entity @Table(name = "USERS") public class User implements java.io.Serializable { private String userid; private String email; @Id @Column(name = "USERID", unique = true, nullable = false,) public String getUserid() { return this.userid; } .... some get/set methods } @Entity @Table(name = "SERVICES") public class CmsService implements java.io.Serializable { private String serviceCode; @Id @Column(name = "SERVICE_CODE", unique = true, nullable = false, length = 100) public String getServiceCode() { return this.serviceCode; } .... some additional fields and get/set methods } I followed this example http://giannigar.wordpress.com/2009/09/04/m ... using-jpa/ Here is some test code: User user = new User(); user.setEmail("e2"); user.setUserid("ui2"); user.setPassword("p2"); CmsService service= new CmsService("cd2","name2"); List<UserService> userServiceList = new ArrayList<UserService>(); UserService userService = new UserService(); userService.setService(service); userService.setUser(user); userService.setBlocked(true); service.getUserServices().add(userService); userDAO.save(user); The problem is that hibernate persists User object and UserService one. No success with the CmsService object I tried to use EAGER fetch - no progress Is it possible to achieve the behaviour I'm expecting with the mapping provided above? Maybe there is some more elegant way of mapping many to many join table with additional column?

    Read the article

  • SQL - table alias scope.

    - by Support - multilanguage SO
    I've just learned ( yesterday ) to use "exists" instead of "in". BAD select * from table where nameid in ( select nameid from othertable where otherdesc = 'SomeDesc' ) GOOD select * from table t where exists ( select nameid from othertable o where t.nameid = o.nameid and otherdesc = 'SomeDesc' ) And I have some questions about this: 1) The explanation as I understood was: "The reason why this is better is because only the matching values will be returned instead of building a massive list of possible results". Does that mean that while the first subquery might return 900 results the second will return only 1 ( yes or no )? 2) In the past I have had the RDBMS complainin: "only the first 1000 rows might be retrieved", this second approach would solve that problem? 3) What is the scope of the alias in the second subquery?... does the alias only lives in the parenthesis? for example select * from table t where exists ( select nameid from othertable o where t.nameid = o.nameid and otherdesc = 'SomeDesc' ) AND select nameid from othertable o where t.nameid = o.nameid and otherdesc = 'SomeOtherDesc' ) That is, if I use the same alias ( o for table othertable ) In the second "exist" will it present any problem with the first exists? or are they totally independent? Is this something Oracle only related or it is valid for most RDBMS? Thanks a lot

    Read the article

  • wxPython: MainLoop() seems to hang

    - by BandGap
    Hi all, my problem stems from the use of wxApp as far as I can tell. Inside a litte subroutine I call a wx.MessageDialog to ask for a yes or no. I retrieve the answer an process some stuff acordingly. My example code below actually works (though it might be ugly) except that the Dialog box stays open after hitting one of the buttons... import wx from os import path def HasFile(filename): if path.isfile(filename ): app = wx.App() dial = wx.MessageDialog(None, 'Die Datei "'+filename+'" wurde gefunden.\nSoll sie eingelesen werden?', 'Bitte antworten', wx.YES_NO | wx.YES_DEFAULT | wx.ICON_QUESTION) result = dial.ShowModal() dial.EndModal(retCode=0) dial.Destroy() app.MainLoop() return result == wx.ID_YES else: return False So while the rest of the program does whatever is expected, the box just sits there. It also seems like my calls to matplotlib later on are producing errors (a Tkinter error to be precise), maybe because of the wx stuff? Edit: I tried to end the app with a call to app.Destroy(). This doesn't change the fact that the box is still there. When I issue a app.IsActive() afterwards the whole program exits (almost like a sys.exit())! How come? Edit 2: Adding a wxApp like this isn't a good idea since the other scripts get affected as well. Subsequent plotting commands don't get displayed and I don't know how to fix this. Thus I decided to remove the DialogBox alltogether.

    Read the article

  • Why does my code fail to create a directory in "C:\Program Files" under Windows 7?

    - by sunil.nishad87
    I am using Windows 7 and I have to run one program in that windows but that program working in Windows XP. This is a Visual C++ program and I am using Visual Studio 2008 for this. When I am running my application, it does not throw any errors, but it does not create a directory in "c:\program files\". So can anyone help me to create directory and exe file? This is the code I am using: char szAppPath[MAX_PATH]; char szFileName[MAX_PATH]; DWORD dwResult; WIN32_FIND_DATA FindFileData; HANDLE hFind; dwResult = ExpandEnvironmentStrings( NULL, szAppPath, MAX_PATH); // "%ProgramFiles%" // do same for NSim directory strcat(szAppPath,"\\NSim"); hFind = FindFirstFile(szAppPath, &FindFileData); if (hFind == INVALID_HANDLE_VALUE) { //Directory Does't Exists create New if(!CreateDirectory(szAppPath,NULL)) //Throw Error { MessageBox("Unable to Create N-SIM directory","NSim Installer"); return ; } } else { //check if is directory or not if(!(FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) { MessageBox("Can't Create N-SIM directory\n Another file with same name exists","NSim Installer"); return ; } FindClose(hFind); } //***************************************N-SIM Application**************************** strcpy(szFileName, szAppPath); HRSRC hRes; if( bRegister == FALSE) { strcat(szFileName,"\\NSim.exe"); //make same name of the Client & Server in program file hRes = FindResource(NULL, MAKEINTRESOURCE(IDR_LANSIMSERVER),RT_RCDATA); if(flagUpgrade ==0) { CString trial = installationDate(); //----- Detemine Expiry Date ----- setRegistry(trial); } }

    Read the article

  • .htaccess trickery multi-language website

    - by user1658741
    I have a website right now that uses two languages (french and english) The way it works right now is that if someone goes to mysite.com/folder/file.php for example, file.php is simply a script that figures out which language to use, get's it's own path and filename(file.php) and serves up mysite.com/en/folder/file.php (if the language is english). However what shows up in the URL is still mysite.com/folder/file.php. For any folder and any file the same script is used. If I want to add a new file I have to add the file to the folder the user types into the browser as well to the en and fr folders. Could I do some .htaccess trickery so that whatever URL is typed, one .php file gets open that checks the language and what folder/file was requested and then serves up the correct language file? here's the php file that is served up for any files in the URL. <?php // Get current document path which is mirrored in the language folders $docpath = $_SERVER['PHP_SELF']; // Get current document name (Used when switching languages so that the same current page is shown when language is changed) $docname = GetDocName(); //call up lang.php which handles display of appropriate language webpage. //lang.php uses $docpath and $docname to give out the proper $langfile. //$docpath/$docname is mirrored in the /lang/en and /lang/fr folders $langfile = GetDocRoot()."/lang/lang.php"; include("$langfile"); //Call up the proper language file to display function GetDocRoot() { $temp = getenv("SCRIPT_NAME"); $localpath=realpath(basename(getenv("SCRIPT_NAME"))); $localpath=str_replace("\\","/",$localpath); $docroot=substr($localpath,0, strpos($localpath,$temp)); return $docroot; } function GetDocName() { $currentFile = $_SERVER["SCRIPT_NAME"]; $parts = Explode('/', $currentFile); $dn = $parts[count($parts) - 1]; return $dn; } ?>

    Read the article

  • Dependencyproperty doesn't have value on load

    - by Jakob
    My problem is this, I have a UC called profile that contains another UC called FollowImageControl. In my Profile.xaml i declaretively bind a property of FollowImageControl called FollowerId to a CurrentUserId from Profile.xaml.cs. Problem is that I CurrentUserId is assigned in Profile.xaml.cs; the Profile.xaml code-behind. This means that I do not initially get the FollowerId. I have these methods in the FollowImageControl.xaml.cs: public static readonly DependencyProperty _followUserId = DependencyProperty.Register("FollowUserId", typeof(Guid), typeof(FollowImageControl), null); public Guid FollowUserId { get { return (Guid)GetValue(_followUserId); } set { SetValue(_followUserId, value); } } public FollowImageControl() { // Required to initialize variables InitializeComponent(); LoggedInUserId = WebContext.Current.User.UserId; var ctx = new NotesDomainContext(); if (ctx.IsFollowingUser(LoggedInUserId, FollowUserId).Value) SwitchToDelete.Begin(); } private void AddImg_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) { if (LoggedInUserId != FollowUserId) { var ctx = new NotesDomainContext(); ctx.FollowUser(FollowUserId, LoggedInUserId); ctx.SubmitChanges(); } } THE WEIRD THING IS that when i insert breakpoints the FollowerUserId in FollowImageControl() is 0, but it has a value in AddImg_MouseLeftButtonDown, and there is no inbetween logic that sets the value of it. How is this??? Here's a little more code info: This is my binding from profile.xaml <internalCtrl:FollowImageControl FollowUserId="{Binding ElementName=ProfileCtrl, Path=CurrentUserId}" /> this is my constructor in profile.xaml.cs wherein the CurrentUserId is set public static readonly DependencyProperty _CurrentUserId = DependencyProperty.Register("CurrentUserId", typeof(Guid), typeof(Profile), null); public Guid CurrentUserId { get { return (Guid)GetValue(_CurrentUserId); } set { SetValue(_CurrentUserId, value); } } public Profile(Guid UserId) { CurrentUserId = UserId; InitializeComponent(); Loaded += new RoutedEventHandler(Profile_Loaded); } I'm seriously dumbfound that one minute the FollowerId has no value, and the next it holds the right, without me having changed the value in the code-behind.

    Read the article

  • Add new Formelemts and transform it with jqtransform

    - by user545782
    I'm just trying to change my formfields with jqtransform. With the following Javascript Code, i add new formfields: <script type="text/javascript"> $(function() { var scntDiv = $('#p_scents'); var i = $('#p_scents p').size() + 1; $('#addScnt').live('click', function() { if(i < 4){ $('<p>\n\ <label for="p_scnts">\n\ <input type="text" id="p_scnt" size="17" name="fmac' + i +'[]" value="" />\n\ <select name="fmac' + i +'[]" size="1" id="p_scnt_a">\n\ <option selected value="K">KABEL</option>\n\ <option value="W">WLAN</option>\n\ <option value="V">VPN</option>\n\ </select>\n\ </label>\n\ </p>').appendTo(scntDiv); i++; } if(i > 3 ){ $('#showaddmac').hide(); } return false; }); $('#remScnt').live('click', function() { if( i > 2 ) { $(this).parents('p').remove(); i--; } if(i < 4 ){ $('#showaddmac').show(); } return false; }); }); </script> this works with out problemes, but the new fields will be not transformed. Does anyone know a solution to the problem? Sry for my bad english :)

    Read the article

  • Properly obsoleting old members in an XML Serializable class in C# VB .NET

    - by George
    Hi! Some time ago I defined a class that was serialized using XML. That class contained a serializable propertyA of integer type. Now I have extended and updated this class, whereby a new propertyB was added, whose type is another class that also has several serializable properties. The new propertyB is now supposed to play the role of propertyA, that is since type of propertyB is another class, one of its members would contain the value that previously propertyA contained, thus making peroptyA obsolete. What I am trying to figure out is how do I make sure that when I desireliaze the OLD version of this class (without propertyB in it), I make sure that the desreializer would take the value of propertyA from the old calss and set it as a value of one of the members of propertyB in a new class? Private WithEvents _Position As Position = New Position(Alignment.MiddleMiddle, 0, True, 0, True) Public Property Position() As Position 'NEW composite property that holds the value of the obsolted property, i.e. Alignment Get Return _Position End Get Set(ByVal value As Position) _Position = value End Set End Property Private _Alignment As Alignment = Alignment.MiddleMiddle <Xml.Serialization.XmlIgnore(), Obsolete("Use Position property instead.")> _ Public Property Alignment() As Alignment'The old, obsoleted property that I guess must be left for compliance with deserializing the old version of this class Get Return _Alignment End Get Set(ByVal value As Alignment) _Alignment = value End Set End Property Can you help me, please?

    Read the article

  • Asynchronous Controller is blocking requests in ASP.NET MVC through jQuery

    - by Jason
    I have just started using the AsyncController in my project to take care of some long-running reports. Seemed ideal at the time since I could kick off the report and then perform a few other actions while waiting for it to come back and populate elements on the screen. My controller looks a bit like this. I tried to use a thread to perform the long task which I'd hoped would free up the controller to take more requests: public class ReportsController : AsyncController { public void LongRunningActionAsync() { AsyncManager.OutstandingOperations.Increment(); var newThread = new Thread(LongTask); newThread.Start(); } private void LongTask() { // Do something that takes a really long time //....... AsyncManager.OutstandingOperations.Decrement(); } public ActionResult LongRunningActionCompleted(string message) { // Set some data up on the view or something... return View(); } public JsonResult AnotherControllerAction() { // Do a quick task... return Json("..."); } } But what I am finding is that when I call LongRunningAction using the jQuery ajax request, any further requests I make after that back up behind it and are not processed until LongRunningAction completes. For example, call LongRunningAction which takes 10 seconds and then call AnotherControllerAction which is less than a second. AnotherControllerAction simply waits until LongRunningAction completes before returning a result. I've also checked the jQuery code, but this still happens if I specifically set "async: true": $.ajax({ async: true, type: "POST", url: "/Reports.aspx/LongRunningAction", dataType: "html", success: function(data, textStatus, XMLHttpRequest) { // ... }, error: function(XMLHttpRequest, textStatus, errorThrown) { // ... } }); At the moment I just have to assume that I'm using it incorrectly, but I'm hoping one of you guys can clear my mental block!

    Read the article

  • modified closure warning in ReSharper

    - by Sarah Vessels
    I was hoping someone could explain to me what bad thing could happen in this code, which causes ReSharper to give an 'Access to modified closure' warning: bool result = true; foreach (string key in keys.TakeWhile(key => result)) { result = result && ContainsKey(key); } return result; Even if the code above seems safe, what bad things could happen in other 'modified closure' instances? I often see this warning as a result of using LINQ queries, and I tend to ignore it because I don't know what could go wrong. ReSharper tries to fix the problem by making a second variable that seems pointless to me, e.g. it changes the foreach line above to: bool result1 = result; foreach (string key in keys.TakeWhile(key => result1)) Update: on a side note, apparently that whole chunk of code can be converted to the following statement, which causes no modified closure warnings: return keys.Aggregate( true, (current, key) => current && ContainsKey(key) );

    Read the article

  • How to send and retrieve in the controller

    - by user281180
    I have the folowing code in my view, however, I can see that I don`t have the values in the controller. What is wrong? In the view I have, <% using (Html.BeginForm()) {%> <%=Html.TextBox("Addresses[0].Line1") %> <%=Html.TextBox("Addresses[0].Line2")%> <%=Html.TextBox("Addresses[1].Line1")%> <%=Html.TextBox("Addresses[1].Line2")%> <input type="submit" name="submitForm" value="Save products" /> <% } %> My classes are as follows: public class Customer { public string FirstName { get; set; } public string Lastname { get; set; } public List<Address> Addresses { get; set; } public Customer() { Addresses = new List<Address>(); } } public class Address { public int Line1 { get; set; } public int Line2 { get; set; } } My controller as follows: public ActionResult Index() { return View(); } [HttpPost] public ActionResult Index(Customer customer) { return View(); }

    Read the article

  • jquery: How to deal with 'this' in ajax callbacks

    - by Svish
    I currently have code similar to this for a form: $('#some-form') .submit(function() { // Make sure we are not already busy if($(this).data('busy')) return false; $(this).data('busy', true); // Do post $.post("some/url", $(this).serialize(), function(data) { if(data.success) // Success is a boolean I set in the result on the server { // Deal with data } else { // Display error } $('#some-form') .removeData('busy'); }); return false; }); My issue is that I would like to somehow remove the need for knowing the form id in the post callback. In the end where I remove the busy data from the form, I'd like to somehow not have that hard coded. Is there any way I can do this? Is there a way I can hand whatever is in this to the post callback function? Since I know the id right now, I can get around it by doing what I have done, but I'd like to know how to not be dependant on knowing the id, since often I don't have an id. (For example if I have a link in each row in a table and all the rows have the same click handler.

    Read the article

  • Recursive breadth-first travel function in Java or C++?

    - by joejax
    Here is a java code for breadth-first travel: void breadthFirstNonRecursive(){ Queue<Node> queue = new java.util.LinkedList<Node>(); queue.offer(root); while(!queue.isEmpty()){ Node node = queue.poll(); visit(node); if (node.left != null) queue.offer(node.left); if (node.right != null) queue.offer(node.right); } } Is it possible to write a recursive function to do the same? At first, I thought this would be easy, so I came out with this: void breadthFirstRecursive(){ Queue<Node> q = new LinkedList<Node>(); breadthFirst(root, q); } void breadthFirst(Node node, Queue<Node> q){ if (node == null) return; q.offer(node); Node n = q.poll(); visit(n); if (n.left != null) breadthFirst(n.left, q); if (n.right != null) breadthFirst(n.right, q); } Then I found it doesn't work. It is actually does the same thing as this: void preOrder(Node node) { if (node == null) return; visit(node); preOrder(node.left); preOrder(node.right); } Has any one thought about this before?

    Read the article

  • in haskell, why do I need to specify type constraints, why can't the compiler figure them out?

    - by Steve
    Consider the function, add a b = a + b This works: *Main> add 1 2 3 However, if I add a type signature specifying that I want to add things of the same type: add :: a -> a -> a add a b = a + b I get an error: test.hs:3:10: Could not deduce (Num a) from the context () arising from a use of `+' at test.hs:3:10-14 Possible fix: add (Num a) to the context of the type signature for `add' In the expression: a + b In the definition of `add': add a b = a + b So GHC clearly can deduce that I need the Num type constraint, since it just told me: add :: Num a => a -> a -> a add a b = a + b Works. Why does GHC require me to add the type constraint? If I'm doing generic programming, why can't it just work for anything that knows how to use the + operator? In C++ template programming, you can do this easily: #include <string> #include <cstdio> using namespace std; template<typename T> T add(T a, T b) { return a + b; } int main() { printf("%d, %f, %s\n", add(1, 2), add(1.0, 3.4), add(string("foo"), string("bar")).c_str()); return 0; } The compiler figures out the types of the arguments to add and generates a version of the function for that type. There seems to be a fundamental difference in Haskell's approach, can you describe it, and discuss the trade-offs? It seems to me like it would be resolved if GHC simply filled in the type constraint for me, since it obviously decided it was needed. Still, why the type constraint at all? Why not just compile successfully as long as the function is only used in a valid context where the arguments are in Num? Thank you.

    Read the article

  • Why does my plist file exist even when I've uninstalled an app and wiped the simulator?

    - by just_another_coder
    I am trying to detect the existence of a plist file on application start. When my data class (descendant of NSObject) is initialized, it loads the plist file. Before it loads, it checks to see if the file exists, and if it doesn't, it sets the data = nil instead of trying to process the array of data in the plist file. However, every time it starts it indicates the file exists. Even when I uninstall the app in the organizer and when wiping the simulator directory (iPhone Simulator/3.0/Applications). I have the following static method in a library class named FileIO: +(BOOL) fileExists:(NSString *)fileName { NSString *path = [FileIO getPath:fileName]; // gets the path to the docs directory if ([[NSFileManager defaultManager] fileExistsAtPath:path]) return YES; else return NO; } In my data class: //if( [FileIO fileExists:kFavorites_Filename] ) [FileIO deleteFile:kFavorites_Filename]; if ([FileIO fileExists:kFavorites_Filename]) {NSLog(@"exists"); The "exists" is logged every time unless I un-comment the method to delete the file. How can the file exist if I've deleted the app? I've deleted the simulator directory and uninstalled on the device but both say it still exists. What gives???

    Read the article

  • Getting rejected value null spring validation

    - by Shabarinath
    Hi in my project when I am trying to validate my form its not showing any error messages even if validation fails (Event Form is not submitted and enters into validation fail block) Here is my code /****************** Post Method *************/ @RequestMapping(value="/property", method = RequestMethod.POST) public String saveOrUpdateProperty(@ModelAttribute("property") Property property, BindingResult result, Model model, HttpServletRequest request) throws Exception { try { if(validateFormData(property, result)) { model.addAttribute("property", new Property()); return "property/postProperty"; } } /********* Validate Block *************/ private boolean validateFormData(Property property, BindingResult result) throws DaoException { if (property.getPropertyType() == null || property.getPropertyType().equals("")) { result.rejectValue("propertyType", "Cannot Be Empty !", "Cannot Be Empty !"); } if (property.getTitle() == null || property.getTitle().equals("")) { result.rejectValue("title", "Cannot Be Empty !", "Cannot Be Empty !"); } return (result.hasFieldErrors() || result.hasErrors()); } But when i debug i can see below one org.springframework.validation.BeanPropertyBindingResult: 1 errors Field error in object 'property' on field 'title': rejected value [null]; codes [Cannot Be Empty !.property.title,Cannot Be Empty !.title,Cannot Be Empty !.java.lang.String,Cannot Be Empty !]; arguments []; default message [Cannot Be Empty !] and this is how i am displaying in jsp file <div class="control-group"> <div class="controls"> <label class="control-label"><span class="required">* </span>Property Type</label> <div class="controls"> <form:input path="title" placeholder="Pin Code" cssClass="form-control border-radius-4 textField"/> <form:errors path="title" style="color:red;"/> </div> </div> </div> Event though when i see the below one when i debug (1 Error its correct) org.springframework.validation.BeanPropertyBindingResult: 1 errors Why it is not displayed in jsp can any one hep me?

    Read the article

  • Show Color Picker Value Code Within Input Text Field in Wordpress

    - by Shwan Namiq
    Hi i have options page for my theme i used color picker jquery plugin in my options page as show in image below. i want when i change the color from color picker automatically show the color value code within the text field.how can do this? this is the code within my options page related to appearing the color picker and text field function to register the options setting function YPE_register_settings_sections_fields() { register_setting ( 'YPE_header_option_group', 'YPE_header_option_name', 'YPE_sanitize_validate_callback' ); add_settings_section ( 'YPE_header_section', 'Header Section', 'YPE_header_section_callback', 'YPE_menu_page_options' ); add_settings_field ( 'YPE_header_bg', 'Header Background', 'YPE_header_bg_callback', 'YPE_menu_page_options', 'YPE_header_section' ); } add_action('admin_init', 'YPE_register_settings_sections_fields'); function to appear the text field and color picker function YPE_header_bg_callback() { $YPE_options = get_option('YPE_header_option_name'); $YPE_header_bg = isset($YPE_options['YPE_header_bg']) ? $YPE_options['YPE_header_bg'] : ''; ?> <div class="input-group color-picker"> <input class="form-control" style="width:80px;" name="YPE_header_option_name[YPE_header_bg]" id="<?php echo 'YPE_header_bg'; ?>" type="text" value="<?php echo $YPE_header_bg; ?>" /> <span class="input-group-btn"> <div id="colorSelector"> <div nam style="background-color: #0000ff"> </div> </div> </span> </div> <script> $("#colorSelector").ColorPicker({ color: '#0000ff', onShow: function (colpkr) { $(colpkr).fadeIn(500); return false; }, onHide: function (colpkr) { $(colpkr).fadeOut(500); return false; }, onChange: function (hsb, hex, rgb) { $('#colorSelector div').css('backgroundColor', '#' + hex); }); </script> <?php }

    Read the article

  • Optimize jQuery code

    - by Dannemannen
    Greetings, Just built some stuff with jQuery, everything works perfect(!), but I would like it to be as optimzed as possible.. what small changes can I do to my code? $(document).ready(function() { // hide the indicator, we use it later $(".indicator").hide(); // start the animation of the progressbar $(".fill").animate({ width: "50px",}, 4000, function() { $(".indicator").effect("pulsate", { times:999 }, 2000);}); // notify-me ajax function $(".btn-submit").click(function() { // get the variable email and put it in a new variable var email = $("input#mail").val(); var dataString = 'mail='+email; $.ajax({ type: "POST", url: "/mail.php", data: dataString, dataType: "json", success: function(msg){ // JSON return, lets do some magic if(msg.status == "ok") { $("#response-box").fadeIn("slow").delay(2000).fadeOut("slow"); $("#fade").fadeIn("slow").delay(2000).fadeOut("slow"); $("#response-box .inner").html("<h1>Thank you.</h1>We'll keep in touch!"); $("#mail").val("e.g. [email protected]"); } else { $("#response-box").fadeIn("slow").delay(2000).fadeOut("slow"); $("#fade").fadeIn("slow").delay(2000).fadeOut("slow"); $("#response-box .inner").html("<h1>Oops.</h1>Please try again!"); } } }); //make sure the form doesn't post return false; }); });

    Read the article

  • Very simple code for number search gives me infinite loop

    - by Joshua
    Hello, I am a newbie Computer Science high school student and I have trouble with a small snippet of code. Basically, my code should perform a basic CLI search in an array of integers. However, what happens is I get what appears to be an infinite loop (BlueJ, the compiler I'm using, gets stuck and I have to reset the machine). I have set break points but I still don't quite get the problem...(I don't even understand most of the things that it tells me) Here's the offending code (assume that "ArrayUtil" works, because it does): import java.util.Scanner; public class intSearch { public static void main(String[] args) { search(); } public static void search() { int[] randomArray = ArrayUtil.randomIntArray(20, 100); Scanner searchInput = new Scanner(System.in); int searchInt = searchInput.nextInt(); if (findNumber(randomArray, searchInt) == -1) { System.out.println("Error"); }else System.out.println("Searched Number: " + findNumber(randomArray, searchInt)); } private static int findNumber(int[] searchedArray, int searchTerm) { for (int i = 0; searchedArray[i] == searchTerm && i < searchedArray.length; i++) { return i; } return -1; } } This has been bugging me for some time now...please help me identify the problem!

    Read the article

  • WCF consumed as WebService adds a boolean parameter?

    - by Martín Marconcini
    I've created the default WCF Service in VS2008. It's called "Service1" public class Service1 : IService1 { public string GetData( int value ) { return string.Format("You entered: {0}", value); } public CompositeType GetDataUsingDataContract( CompositeType composite ) { if ( composite.BoolValue ) { composite.StringValue += "Suffix"; } return composite; } } It works fine, the interface is IService1: [ServiceContract] public interface IService1 { [OperationContract] string GetData( int value ); [OperationContract] CompositeType GetDataUsingDataContract( CompositeType composite ); // TODO: Add your service operations here } This is all by default; Visual Studio 2008 created all this. I then created a simple Winforms app to "test" this. I added the Service Reference to my the above mentioned service and it all works. I can instanciate and call myservice1.GetData(100); and I get the result. But I was told that this service will have to be consumed by a Winforms .NET 2.0 app via Web Services, so I proceeded to add the reference to a new Winforms .NET 2.0 application created from scratch (only one winform called form1). This time, when adding the "web reference", it added the typical "localhost" one belonging to webservices; the wizard saw the WCF Service (running on background) and added it. When I tried to consume this, I found out that the GetData(int) method, was now GetData(int, bool). Here's the code private void button1_Click( object sender, EventArgs e ) { localhost.Service1 s1 = new WindowsFormsApplication2.localhost.Service1(); Console.WriteLine(s1.GetData(100, false)); } Notice the false in the GetData call? I don't know what that parameter is or where did that come from, it is called "bool valueSpecified". Does anybody know where this is coming from? Anything else I should do to consume a WCF Service as a WebService from .NET 2.0? (winforms).

    Read the article

< Previous Page | 545 546 547 548 549 550 551 552 553 554 555 556  | Next Page >