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  • jQuery Form Validation being bypassed

    - by user1953681
    Can someone tell me what is wrong with my jQuery validation? It is not validating my form, rather, just ignoring the code resulting in no check of the inputs. Form: <form class="form" accept-charset="UTF-8" action="URL-to-complete-form" method="POST" onsubmit="return validateForm();"> <input class="form-name" type="text" placeholder="Name"></div> <input class="form-email" type="text"placeholder="Email"></div> <input style="background-color: #fc8f12;" type="submit" value="Subscribe"> </div> </form> Javascript: function validateForm() { // Validate Name var title = $(".form-name").val(); if (title=="" ||title=="Name" || title==null) { } else { alert("Please enter a name!"); } // Validate Email var email = $(".form-email").val(); if ((/(.+)@(.+){2,}\.(.+){2,}/.test(email)) || email=="" || email=="Email" || email==null) { } else { alert("Please enter a valid email"); } return false; } Thank you all for your time and help.

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  • How to get encoding from MAPI message with PR_BODY_A tag (windows mobile)?

    - by SadSido
    Hi, everyone! I am developing a program, that handles incoming e-mail and sms through windows-mobile MAPI. The code basically looks like that: ulBodyProp = PR_BODY_A; hr = piMessage->OpenProperty(ulBodyProp, NULL, STGM_READ, 0, (LPUNKNOWN*)&piStream); if (hr == S_OK) { // ... get body size in bytes ... STATSTG statstg; piStream->Stat(&statstg, 0); ULONG cbBody = statstg.cbSize.LowPart; // ... allocate memory for the buffer ... BYTE* pszBodyInBytes = NULL; boost::scoped_array<BYTE> szBodyInBytesPtr(pszBodyInBytes = new BYTE[cbBody+2]); // ... read body into the pszBodyInBytes ... } That works and I have a message body. The problem is that this body is multibyte encoded and I need to return a Unicode string. I guess, I have to use ::MultiByteToWideChar() function, but how can I guess, what codepage should I apply? Using CP_UTF8 is naive, because it can simply be not in UTF8. Using CP_ACP works, well, sometimes, but sometimes does not. So, my question is: how can I retrieve the information about message codepage. Does MAPI provide any functions for it? Or is there a way to decode multibyte string, other than MultiByteToWideChar()? Thanks!

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  • How to implement a Client-side Ajax Login on Asp.Net MVC (A link to the solution for Asp.Net Webform

    - by Matt
    Hi, I'm trying to implement a client-side ajax login on Asp.Net MVC. I used to have this set up just fine on WebForms, but now that I've moved to MVC it's giving me some troubles. If you'd like a tutorial on Client-side Ajax Login for Asp.Net Webforms, it can be found here -- Easy, A++ Now... for some reason it's not working for Asp.Net MVC. I used the exact same tutorial as for the Webforms, except when it executes the ssa.login() (equivalently: Sys.Services.AuthenticationService.login()) it's not doing anything. I have alerts in both the onLoginComplete() function and the onError() function. As well I have an alert before the ssa.login gets called and right after... function loginHandler() { var username = $("#login_UserName").val(); var password = $("#login_Password").val(); var isPersistent = $("#login_RememberMe").attr("checked"); var customInfo = null; var redirectUrl = null; // Log them in. alert("try login"); ssa.login(username, password, isPersistent, customInfo, redirectUrl, onLoginComplete, onError); alert("made it here"); } The first alert fires but the second one doesn't which means the function is failing. Here's the function I pulled from Asp.Net Ajax to show you: function(c, b, a, h, f, d, e, g) { this._invoke(this._get_path(), "Login", false, { userName: c, password: b, createPersistentCookie: a }, Function.createDelegate(this, this._onLoginComplete), Function.createDelegate(this, this._onLoginFailed), [c, b, a, h, f, d, e, g]); } Anyone have any idea of why it's failing?

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  • Error when linking C executable to OpenCV

    - by Ghilas BELHADJ
    I'm compiling OpenCV under Ubuntu 13.10 using cMake. i've already compiled c++ programs and they works well. now i'm trying to compile a C file using this cMakeLists.txt cmake_minimum_required (VERSION 2.8) project (hello) find_package (OpenCV REQUIRED) add_executable (hello src/test.c) target_link_libraries (hello ${OpenCV_LIBS}) here is the test.c file: #include <stdio.h> #include <stdlib.h> #include <opencv/highgui.h> int main (int argc, char* argv[]) { IplImage* img = NULL; const char* window_title = "Hello, OpenCV!"; if (argc < 2) { fprintf (stderr, "usage: %s IMAGE\n", argv[0]); return EXIT_FAILURE; } img = cvLoadImage(argv[1], CV_LOAD_IMAGE_UNCHANGED); if (img == NULL) { fprintf (stderr, "couldn't open image file: %s\n", argv[1]); return EXIT_FAILURE; } cvNamedWindow (window_title, CV_WINDOW_AUTOSIZE); cvShowImage (window_title, img); cvWaitKey(0); cvDestroyAllWindows(); cvReleaseImage(&img); return EXIT_SUCCESS; } it returns me this error whene running cmake . then make to the project: Linking C executable hello /usr/bin/ld: CMakeFiles/hello.dir/src/test.c.o: undefined reference to symbol «lrint@@GLIBC_2.1» /lib/i386-linux-gnu/libm.so.6: error adding symbols: DSO missing from command line collect2: error: ld returned 1 exit status make[2]: *** [hello] Erreur 1 make[1]: *** [CMakeFiles/hello.dir/all] Erreur 2 make: *** [all] Erreur 2

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  • Is there alternative way to write this query?

    - by Kugel
    I have tables A, B, C, where A represents items which can have zero or more sub-items stored in C. B table only has 2 foreign keys to connect A and C. I have this sql query: select * from A where not exists (select * from B natural join C where B.id = A.id and C.value > 10); Which says: "Give me every item from table A where all sub-items have value less than 10. Is there a way to optimize this? And is there a way to write this not using exists operator?

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  • Reading Unicode files line by line C++

    - by Roger Nelson
    What is the correct way to read Unicode files line by line in C++? I am trying to read a file saved as Unicode (LE) by Windows Notepad. Suppose the file contains simply the characters A and B on separate lines. In reading the file byte by byte, I see the following byte sequence (hex) : FE FF 41 00 0D 00 0A 00 42 00 0D 00 0A 00 So 2 byte BOM, 2 byte 'A', 2byte CR , 2byte LF, 2 byte 'B', 2 byte CR, 2 byte LF . I tried reading the text file using the following code: std::wifstream file("test.txt"); file.seekg(2); // skip BOM std::wstring A_line; std::wstring B_line; getline(file,A_line); // I get "A" getline(file,B_line); // I get "\0B" I get the same results using operator instead of getline file >> A_line; file >> B_line; It appears that the single byte CR character is is being consumed only as the single byte. or CR NULL LF is being consumed but not the high byte NULL. I would expect wifstream in text mode would read the 2byte CR and 2byte LF. What am I doing wrong? It does not seem right that one should have to read a text file byte by byte in binary mode just to parse the new lines.

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  • Visual studio feature - commenting code Ctrl K - Ctrl C

    - by Michael
    I commented on this answer some time ago regarding how visual studio comments out code with // or /* */. I was thinking to revise the answer (to include my findings) but I had to test it first, which kind of confused me. My finding is that depending on where your marker is when you press Ctrl - K, Ctrl - C you will get either // or /* */. So I tried it out on the following code: [1] [2]FD_ZERO(&mFSet); FD_SET(user->mSender, &mFSet); timeval zeroTime = { 0, 0 }; int sel = select(0, NULL, &mFSet, NULL, &zeroTime); [3] if (sel == SOCKET_ERROR){ [5]return false; [4] } if (sel == 0){ [6] return false; [7] } The [x] is markerpositions. All [1] positions give // for all marked lines. However Start position End Position: gives: [2] [3] : /* */ [2] [4] : // [2] [5] : /* */ [2] [more than 5] : // [5] [6] : /* */ [5] [7] : // I guess it has to do with forward indentation (not backwards), that whenever code is indented more than the starting line you get // except when you haven't selected any text on the indented line ([2] [5]). But why the distinction? Why not use /* */ for when you start at [2] and // when you start at [1]?

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  • PHP Overloading, singleton instance

    - by jamalali81
    I've sort of created my own MVC framework and am curious as to how other frameworks can send properties from the "controller" to the "view". Zend does something along the lines of $this->view->name = 'value'; My code is: file: services_hosting.php class services_hosting extends controller { function __construct($sMvcName) { parent::__construct($sMvcName); $this->setViewSettings(); } public function setViewSettings() { $p = new property; $p->banner = '/path/to/banners/home.jpg'; } } file: controller.php class controller { public $sMvcName = "home"; function __construct($sMvcName) { if ($sMvcName) { $this->sMvcName = $sMvcName; } include('path/to/views/view.phtml'); } public function renderContent() { include('path/to/views/'.$this->sMvcName.'.phtml'); } } file: property.php class property { private $data = array(); protected static $_instance = null; public static function getInstance() { if (null === self::$_instance) { self::$_instance = new self(); } return self::$_instance; } public function __set($name, $value) { $this->data[$name] = $value; } public function __get($name) { if (array_key_exists($name, $this->data)) { return $this->data[$name]; } } public function __isset($name) { return isset($this->data[$name]); } public function __unset($name) { unset($this->data[$name]); } } In my services_hosting.phtml "view" file I have: <img src="<?php echo $this->p->banner ?>" /> This just does not work. Am I doing something fundamentally wrong or is my logic incorrect? I seem to be going round in circles at the moment. Any help would be very much appreciated.

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  • Web User Control og Event

    - by Mcoroklo
    I have a web user control, CreateQuestion.ascx, in ASP.NET. I want an event "QuestionAdded" to fire when a specific button is clicked. I don't want to send any data, I just want to know WHEN the button is fired. My implementation: CreateQuestion.ascx: public event EventHandler QuestionAdded; protected virtual void OnQuestionAdded(EventArgs e) { if (QuestionAdded != null) QuestionAdded(this, e); } /// This is the button I want to know when is fired protected void SubmitButton_Click(object sender, EventArgs e) { //question.Save(); this.OnQuestionAdded(new EventArgs()); } On the page AnswerQuestion.aspx, I use this: private void SetupControls(int myId) { CreateQuestionControl.QuestionAdded += new EventHandler(QuestionAdded); } private void QuestionAdded(object sender, EventArgs e) { Response.Write("HEJ KARL?"); } My problem No matter what, the event is never fired. I know that both SetupControls() is being run, and the code behind the button which should fire the event is run. When I debug, I can see the event QuestionAdded always are null. How do I make this work? Thanks a lot

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  • Test MVC using moq

    - by Raminder
    I am new to moq and I was trying to test a controller (MVC) behaviour that when the view raises a certain event, controller calls a certain function on model, here are the classes - public class Model { public void CalculateAverage() { ... } ... } public class View { public event EventHandler CalculateAverage; private void RaiseCalculateAverage() { if (CalculateAverage != null) { CalculateAverage(this, EventArgs.Empty); } } ... } public class Controller { private Model model; private View view; public Controller(Model model, View view) { this.model = model this.view = view; view.CalculaeAverage += view_CalculateAverage; } priavate void view_CalculateAverage(object sender, EventArgs args) { model.CalculateAverage(); } } and the test - [Test] public void ModelCalculateAverageCalled() { Mock<Model> modelMock = new Mock<Model>(); Mock<View> viewMock = new Mock<View>(); Controller controller = new Controller(modelMock.Object, viewMock.Object); viewMock.Raise(x => x.CalculateAverage += null, new EventArgs.Empty); modelMock.Verify(x => x.CalculateAverage()); //never comes here, test fails in above line and exits Assert.True(true); } The issue is that the test is failing in the second last line with "Invocation was not performed on the mock: x = x.CalculateAverage()". Another thing I noticed is that the test terminates on this second last line and the last line is never executed. Am I doing everything correct?

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  • WordPress Get 1 attachment per post from X category outside the loop

    - by davebowker
    Hey, Hope someone can help with this. What I want is to display 5 attachments but only 1 attachment from each post from a specific category in the sidebar, which links to the posts permalink. I'm using the following code so far which gets all attachments from all posts, but some posts have more than 1 attachment and I just want to show the first one, and link it to the permalink of the post. So although the limit is 5 posts, if one post has 4 attachments then currently it will show 4 from one, and 1 from the other totalling 5, when what I want it to do is just show 1 from each of 5 different posts. <?php $args = array( 'post_type' => 'attachment', 'numberposts' => 5, 'post_status' => null, 'post_parent' => null, // any parent 'category_name' => 'work', ); $attachments = get_posts($args); if ($attachments) { foreach ($attachments as $post) { setup_postdata($post); the_title(); the_permalink(); the_attachment_link($post->ID, false); the_excerpt(); } } ?> Cheers. Dave

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  • select failing with C program but not shell

    - by Gary
    So I have a parent and child process, and the parent can read output from the child and send to the input of the child. So far, everything has been working fine with shell scripts, testing commands which input and output data. I just tested with a simple C program and couldn't get it to work. Here's the C program: #include <stdio.h> int main( void ) { char stuff[80]; printf("Enter some stuff:\n"); scanf("%s", stuff); return 0; } The problem with with the C program is that my select fails to read from the child fd and hence the program cannot finish. Here's the bit that does the select.. //wait till child is ready fd_set set; struct timeval timeout; FD_ZERO( &set ); // initialize fd set FD_SET( PARENT_READ, &set ); // add child in to set timeout.tv_sec = 3; timeout.tv_usec = 0; int r = select(FD_SETSIZE, &set, NULL, NULL, &timeout); if( r < 1 ) { // we didn't get any input exit(1); } Does anyone have any idea why this would happen with the C program and not a shell one? Thanks!

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  • Why does first call to java.io.File.createTempFile(String,String,File) take 5 seconds on Citrix?

    - by Ben Roling
    While debugging slow startup of an Eclipse RCP app on a Citrix server, I came to find out that java.io.createTempFile(String,String,File) is taking 5 seconds. It does this only on the first execution and only for certain user accounts. Specifically, I am noticing it Citrix anonymous user accounts. I have not tried many other types of accounts, but this behavior is not exhibited with an administrator account. Also, it does not matter if the user has access to write to the given directory or not. If the user does not have access, the call will take 5 seconds to fail. If they do have access, the call with take 5 seconds to succeed. This is on a Windows 2003 Server. I've tried Sun's 1.6.0_16 and 1.6.0_19 JREs and see the same behavior. I googled a bit expecting this to be some sort of known issue, but didn't find anything. It seems like someone else would have had to have run into this before. The Eclipse Platform uses File.createTempFile() to test various directories to see if they are writeable during initialization and this issue adds 5 seconds to the startup time of our application. I imagine somebody has run into this before and might have some insight. Here is sample code I executed to see that it is indeed this call that is consuming the time. I also tried it with a second call to createTempFile and notice that subsequent calls return nearly instantaneously. public static void main(final String[] args) throws IOException { final File directory = new File(args[0]); final long startTime = System.currentTimeMillis(); File file = null; try { file = File.createTempFile("prefix", "suffix", directory); System.out.println(file.getAbsolutePath()); } finally { System.out.println(System.currentTimeMillis() - startTime); if (file != null) { file.delete(); } } } Sample output of this program is the following: C:\java.exe -jar filetest.jar C:/Temp C:\Temp\prefix8098550723198856667suffix 5093

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  • visual studio intellisense error

    - by rakkarage
    template <typename T> class Test { friend Test<T> & operator * (T lhs, const Test<T> & rhs) { Test<T> r(rhs); // return r *= lhs; } } 4 IntelliSense: identifier "T" is undefined why is T defined on line 3 but not line 4? i mean i guess its not a real error just an intellisense error... it works anyway but is there something wrong? can i fix it? or remove the red squiggles somehow? thanks i am using visual studio 2010... i wonder if this happens in other versions as well?

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  • access settings from whole jquery component

    - by Pacuraru Daniel
    I am trying to develop a jquery component for dialog modals and i dont know how to access the settings from all component functions. I need to access settings,zIndex from open function and it seems to not work. (function($) { var methods = { init: function(options) { var defaults = { bgClass: "fancy-dialog-bg", bgShow: null, zIndex: 100, show: null }; var settings = $.extend(defaults, options); return this.each(function() { var obj = $(this).hide().css("position", "fixed").css("z-index", settings.zIndex).css("left", "300px").css("top", "200px"); }); }, open: function() { // alert(settings.zIndex); not working var tes = $("<div></div>").css("backgroundColor", "#f00").css("position", "fixed").css("z-index", "99").css("width", "50%").css("height", "100%").css("left", "0").css("top", "0"); $('body').append(tes); var obj = $(this); obj.show(); }, close: function() { var obj = $(this); $("#fancy-dialog-bg-" + obj.attr('id')).remove(); obj.hide(); } }; $.fn.fancyDialog = function(method) { if (methods[method]) { return methods[method].apply(this, Array.prototype.slice.call(arguments, 1)); } else if (typeof method === 'object' || !method) { return methods.init.apply(this, arguments); } else { $.error('Method ' + method + ' does not exist.'); } }; })(jQuery);

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  • Short names versus long names in Windows

    - by normski
    I have some code which gets the short name from a file path, using GetShortNameW(), and then later retrieves the long name view GetLongNameA(). The original file is of the form "C:/ProgramData/My Folder/File.ext" However, following conversion to short, then back to long, the filename becomes "C:/Program Files/My Folder/Filename.ext". The short name is of the form "C:/PROGRA~2/MY_FOL~1/FIL~1.EXT" The short name is being incorrectly resolved. The code compiles using VS 2005 on Windows 7 (I cannot upgrade the project to VS2008) Does anybody have any idea why this might be happening? DWORD pathLengthNeeded = ::GetShortPathNameW(aRef->GetFilePath().c_str(), NULL, 0); if(pathLengthNeeded != 0) { WCHAR* shortPath = new WCHAR[pathLengthNeeded]; DWORD newPathNameLength = ::GetShortPathNameW(aRef->GetFilePath().c_str(), shortPath, pathLengthNeeded); if(newPathNameLength != 0) { UI_STRING unicodePath(shortPath); std::string asciiPath = StringFromUserString(unicodePath); pathLengthNeeded = ::GetLongPathNameA(asciiPath.c_str(),NULL, 0); if(pathLengthNeeded != 0) {// convert it back to a long path if possible. For goodness sake can't we use Unicode throughout?F char* longPath = new char[pathLengthNeeded]; DWORD newPathNameLength = ::GetLongPathNameA(asciiPath.c_str(), longPath, pathLengthNeeded); if(newPathNameLength != 0) { std::string longPathString(longPath, newPathNameLength); asciiPath = longPathString; } delete [] longPath; } SetFullPathName(asciiPath); } delete [] shortPath; }

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  • Problem of using cin twice.

    - by gc
    Here is the code: string str; cinstr; cout<<"first input:"<<str<<endl; getline(cin, str); cout<<"line input:"<<str<<endl; The result is that getline never pauses for user input, therefore the second output is always empty. After spending some time on it, I realized after the first call "cinstr", it seems '\n' is still stored in cin (using cin.peek() to check), which ends getline immediately. The solution will be adding one more line between the first usage and the second one: cin.ignore(numeric_limits::max(), '\n'); However, I still don't understand, why is '\n' left there after the first call? What does istream& operator really do?

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  • Html Select tabindex not working correctly in Chrome Browser

    - by Shauni
    Hello there, this is a problem I'm currently facing : I've made a <select id="nationalityArea.id" tabindex="6" name="nationalityArea.id"> <option value="null"></option> <option value="619">Îles Cook</option> <option value="646">Îles Féroé</option> <option value="625">Îles Salomon</option> <option value="598">Îles Vierges Américaines</option> <option value="572">Îles Vierges Britanniques</option> </select> Looks fine right ? The problem is that the tabindex method works perfectly on firefox and internet explorer but not on chrome... I think the problem came from the < g:select name="nationalityAreaId" from="${myValue}" tabindex="6" optionKey="id" value="${user?.profile?.nationalityAreaId}" noSelection="['null': '']"/ But not being a Browser specialist is hurting me on this problem. Has anyone already faced this ? And more importantly, found a solution ? Thanks

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  • caching images that are retrieved

    - by Rahul Varma
    Hi, I am retrieving a list of images and text from a web service. The images are getting displayed in the list view. But the problem is, when i scroll down the list the entire images are getting loaded once again. When i scroll twice or thrice there is a OutofMemory occuring... Can anyone tell me how to cache the images and also to avoid the loading of the images that are already loaded when i scroll down. I have tried to increase inSampleSize but it didnt work... Here's the code.... public static Bitmap loadImageFromUrl(String url) { InputStream inputStream; Bitmap b; try { inputStream = (InputStream) new URL(url).getContent(); BitmapFactory.Options bpo= new BitmapFactory.Options(); b=BitmapFactory.decodeStream(inputStream, null,bpo ); b.recycle(); bpo.inSampleSize=2; return b; } catch (IOException e) { throw new RuntimeException(e); } // return null; }

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  • Unit testing code which uses Umbraco v4 API

    - by Jason Evans
    I'm trying to write a suite of integration tests, where I have custom code which uses the Umbraco API. The Umbraco database lives in a SQL Server CE 4.0 database (*.sdf file) and I've managed to get that association working fine. My problem looks to be dependancies in the Umbraco code. For example, I would like to create a new user for my tests, so I try: var user = User.MakeNew("developer", "developer", "mypassword", "[email protected]", adminUserType); Now as you can see, I have pass a user type which is an object. I've tried two separate ways to create the user type, both of which fail due to a null object exception: var adminUserType = UserType.GetUserType(1); var adminUserType2 = new UserType(1); The problem is that in each case the UserType code calls it's Cache method which uses the HttpRuntime class, which naturally is null. My question is this: Can someone suggest a way of writing integration tests against Umbraco code? Will I have to end up using a mocking framework such as TypeMock or JustMock?

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  • How does Hibernate detect dirty state of an entity object?

    - by ???'Lenik
    Is it using some kind of byte codes modification to the original classes? Or, maybe Hibernate get the dirty state by compare the given object with previously persisted version? I'm having a problem with hashCode() and equals() methods for complicated objects. I feel it would be very slow to compute hash code if the object has collection members, and cyclic references are also a problem. If Hibernate won't use hashCode()/equals() to check the dirty state, I guess I should not use equals()/hashCode() for the entity object (not value object), but I'm also afraid if the same operator (==) is not enough. So, the questions are: How does Hibernate know if a property of an object is changed? Do you suggest to override the hashCode()/equals() methods for complicated objects? What if they contains cyclic references? And, also, Would hashCode()/equals() with only the id field be enough?

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  • C# : Number Conversion Problem

    - by Sayem Ahmed
    Today I faced a strange problem in C#. I have an ASP.NET page where user can enter certain price, quantity etc. I get the price value, convert it to double, then multiply it with 100 and then typecast it to an integer. When the price is "33.30", after converting it to double it remains 33.3 (obviously...), but after multiplying it with 100, it becomes 3329.9999999999995, and when I cast it to integer by applying simple cast operator "(int) (price * 100) ", it becomes 3329. Right now I have no idea why this is happening. So I thought may be you guys can help :) .

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  • Using twig variable to dynamically call an imported macro sub-function

    - by Chausser
    I am attempting if use a variable to call a specific macro name. I have a macros file that is being imported {% import 'form-elements.html.twig' as forms %} Now in that file there are all the form element macros: text, textarea, select, radio etc. I have an array variable that gets passed in that has an elements in it: $elements = array( array( 'type'=>'text, 'value'=>'some value', 'atts'=>null, ), array( 'type'=>'text, 'value'=>'some other value', 'atts'=>null, ), ); {{ elements }} what im trying to do is generate those elements from the macros. they work just fine when called by name: {{ forms.text(element.0.name,element.0.value,element.0.atts) }} However what i want to do is something like this: {% for element in elements %} {{ forms[element.type](element.name,element.value,element.atts) }} {% endfor %} I have tried the following all resulting in the same error: {{ forms["'"..element.type.."'"](element.name,element.value,element.atts) }} {{ forms.(element.type)(element.name,element.value,element.atts) }} {{ forms.{element.type}(element.name,element.value,element.atts) }} This unfortunately throws the following error: Fatal error: Uncaught exception 'LogicException' with message 'Attribute "value" does not exist for Node "Twig_Node_Expression_GetAttr".' in Twig\Environment.php on line 541 Any help or advice on a solution or a better schema to use would be very helpful.

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  • Consing lists with user-defined type in Haskell

    - by user1319603
    I have this type I defined myself: data Item = Book String String String Int -- Title, Author, Year, Qty | Movie String String String Int -- Title, Director, Year, Qty | CD String String String Int deriving Show -- Title, Artist, Year, Qty I've created an empty list all_Items = [] With the following function I am trying to insert a new book of type Item (Book) into the all_Items addBook all_Items = do putStrLn "Enter the title of the book" tit <- getLine putStrLn "Enter the author of the book" aut <- getLine putStrLn "Enter the year this book was published" yr <- getLine putStrLn "Enter quantity of copies for this item in the inventory" qty <- getLine Book tit aut yr (read qty::Int):all_Items return(all_Items) I however am receiving this error: Couldn't match expected type `IO a0' with actual type `[a1]' The error points to the line where I am using the consing operator to add the new book to the list. I can gather that it is a type error but I can't figure out what it is that I am doing wrong and how to fix it. Thanks in Advance!

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  • When does ref($variable) return 'IO'?

    - by Zaid
    Here's the relevant excerpt from the documentation of the ref function: The value returned depends on the type of thing the reference is a reference to. Builtin types include: SCALAR ARRAY HASH CODE REF GLOB LVALUE FORMAT IO VSTRING Regexp Based on this, I imagined that calling ref on a filehandle would return 'IO'. Surprisingly, it doesn't: use strict; use warnings; open my $fileHandle, '<', 'aValidFile'; close $fileHandle; print ref $fileHandle; # prints 'GLOB', not 'IO' perlref tries to explain why: It isn't possible to create a true reference to an IO handle (filehandle or dirhandle) using the backslash operator. The most you can get is a reference to a typeglob, which is actually a complete symbol table entry [...] However, you can still use type globs and globrefs as though they were IO handles. In what circumstances would ref return 'IO' then?

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