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  • In c++ is there any Events/delegates/interfaces/notifications! anything?

    - by Bach
    Say i have these classes ViewA and ViewB In objective C using the delegate pattern I could do @protocol ViewBDelegate{ - (void) doSomething(); } then in ViewB interface: id<ViewBDelegate> delegate; then in ViewA implementation i set the delegate: viewB.delegate = self; and now I can call in doSomething from viewB onto any that unknown type delegate. [delegate doSomething]; "C++ How to Program" has been the worse read an can't find simple examples that demonstrates basic design patterns. What i'm looking for in C++ is: events ActionScript and java either delegates or notifications in Objective C anything that allows class A, Class B and Class C to know that ClassX didSomething()!!! thanks

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  • foo and _foo - about variables inside a class

    - by kame
    class ClassName(object): """ """ def __init__(self, foo, bar): """ """ self.foo = foo # read-write property self.bar = bar # simple attribute def _set_foo(self, value): self._foo = value def _get_foo(self): return self._foo foo = property(_get_foo, _set_foo) a = ClassName(1,2) #a._set_foo(3) print a._get_foo() When I print a._get_foo() the function _get_foo prints the variable self._foo . But where does it come from? self._foo and self.foo are different, aren't they?

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  • Returning currently displayed index of an array Javascript...

    - by Jeff Kindred
    I have a simple array with x number of items. I am displaying them individually via a link click... I want to update a number that say 1 of 10. when the next one is displayed i want it to display 2 of 10 etc... I have looked all around and my brain is fried right now... I know its simple I just cant get it out. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title>Page Title</title> <link rel="stylesheet" href="style.css" type="text/css" media="screen" charset="utf-8"/> <script type="text/javascript"> var quotations = new Array() quotations[0]= "1" quotations[1]= "2" quotations[2]= "3" quotations[3]= "4" quotations[4]= "5" quotations[5]= "6" quotations[6]= "7" numQuotes = quotations.length; curQuote = 1; function move( xflip ) { curQuote = curQuote + xflip; if (curQuote > numQuotes) { curQuote = 1 ; } if (curQuote == 0) { curQuote = numQuotes ; } document.getElementById('quotation').innerHTML=quotations[curQuote - 1]; } var curPage = //this is where the current index should go </script> </head> <body> <div id="quotation"> <script type="text/javascript">document.write(quotations[0]);</script> </div> <div> <p><a href="javascript();" onclick="move(-1)">GO back</a> <script type="text/javascript">document.write(curPage + " of " + numQuotes)</script> <a href="javascript();" onclick="move(1)">GO FORTH</a></p> </div> </body> </html>

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  • What are the books about Open-Source that everyone interested in should read?

    - by Edu Zamora
    Currently I am working and running my first Open-Source project and though I am quite happy how things are working so far, I have the feeling that a lot of things could be done better. So, what books about Open-Source would you recommend me in order to help filling this gap and making things better every day? What are the books that influenced you the most? I am especially interested in: - How to organize and run an Open-Source project - Best practices - Manage and involve users and developers - How to announce and do the releases - Legal issues

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  • Regular Expression Sanitize (PHP)

    - by atif089
    Hello, I would like to sanitize a string in to a URL so this is what I basically need. Everything must be removed except alphanumeric characters and spaces and dashed. Spaces should be converter into dashes. Eg. This, is the URL! must return this-is-the-url Thanks

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  • How to display multiple categories and products underneath each category?

    - by shin
    Generally there is a category menu and each link to a category page where shows all the items under that category. Now I need to show all the categories and products underneath with PHP/MySQL in the same page. So it will be like this. Category 1 description of category 1 item 1 item 2 .. Category 2 description of category 2 item 5 item 6 .. Category 3 description of category 3 item 8 item 9 ... ... I have category and product table in my database. But I am not sure how to proceed. CREATE TABLE IF NOT EXISTS `omc_product` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) NOT NULL, `shortdesc` varchar(255) NOT NULL, `longdesc` text NOT NULL, `thumbnail` varchar(255) NOT NULL, `image` varchar(255) NOT NULL, `product_order` int(11) DEFAULT NULL, `class` varchar(255) DEFAULT NULL, `grouping` varchar(16) DEFAULT NULL, `status` enum('active','inactive') NOT NULL, `category_id` int(11) NOT NULL, `featured` enum('none','front','webshop') NOT NULL, `other_feature` enum('none','most sold','new product') NOT NULL, `price` float(7,2) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ; CREATE TABLE IF NOT EXISTS `omc_category` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) NOT NULL, `shortdesc` varchar(255) NOT NULL, `longdesc` text NOT NULL, `status` enum('active','inactive') NOT NULL, `parentid` int(11) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ; I will appreciate your help. Thanks in advance.

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  • How do Arrays work in C#?

    - by Slateboard
    I know that they are used to store data, but I have a difficult time understanding exactly how to use them in a program. In addition, I found this site with a tetris clone tutorial (the actual tutorial is missing). It uses arrays, but I can't really make sense of how it works. Here's an example of the code - public int[, ,] TShape = new int[4, 4, 2] { {{1, 0}, {0, 1}, {1, 1}, {2, 1}}, {{1, 0}, {0, 1}, {1, 1}, {1, 2}}, {{0, 0}, {1, 0}, {2, 0}, {1, 1}}, {{0, 0}, {0, 1}, {1, 1}, {0, 2}}}; Could it be that I'm looking too hard into this, or perhaps there's something I'm not grasping about it?

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  • Model in sub-directory via app_label?

    - by prometheus
    In order to place my models in sub-folders I tried to use the app_label Meta field as described here. My directory structure looks like this: project apps foo models _init_.py bar_model.py In bar_model.py I define my Model like this: from django.db import models class SomeModel(models.Model): field = models.TextField() class Meta: app_label = "foo" I can successfully import the model like so: from apps.foo.models.bar_model import SomeModel However, running: ./manage.py syncdb does not create the table for the model. In verbose mode I do see, however, that the app "foo" is properly recognized (it's in INSTALLED_APPS in settings.py). Moving the model to models.py under foo does work. Is there some specific convention not documented with app_label or with the whole mechanism that prevents this model structure from being recognized by syncdb?

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  • do the Python libraries have a natural dependence on the global namespace?

    - by msw
    I first ran into this when trying to determine the relative performance of two generators: t = timeit.repeat('g.get()', setup='g = my_generator()') So I dug into the timeit module and found that the setup and statement are evaluated with their own private, initially empty namespaces so naturally the binding of g never becomes accessible to the g.get() statement. The obvious solution is to wrap them into a class, thus adding to the global namespace. I bumped into this again when attempting, in another project, to use the multiprocessing module to divide a task among workers. I even bundled everything nicely into a class but unfortunately the call pool.apply_async(runmc, arg) fails with a PicklingError because buried inside the work object that runmc instantiates is (effectively) an assignment: self.predicate = lambda x, y: x > y so the whole object can't be (understandably) pickled and whereas: def foo(x, y): return x > y pickle.dumps(foo) is fine, the sequence bar = lambda x, y: x > y yields True from callable(bar) and from type(bar), but it Can't pickle <function <lambda> at 0xb759b764>: it's not found as __main__.<lambda>. I've given only code fragments because I can easily fix these cases by merely pulling them out into module or object level defs. The bug here appears to be in my understanding of the semantics of namespace use in general. If the nature of the language requires that I create more def statements I'll happily do so; I fear that I'm missing an essential concept though. Why is there such a strong reliance on the global namespace? Or, what am I failing to understand? Namespaces are one honking great idea -- let's do more of those!

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  • c++ meaning of the use of const in the signature

    - by jbu
    Please help me understand the following signature: err_type funcName(const Type& buffer) const; so for the first const, does that mean the contents of Type cannot change or that the reference cannot change? secondly, what does the second const mean? I don't really even have a hint. Thanks in advance, jbu

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  • C++: Trouble with templates (C2064)

    - by Rosarch
    I'm having compiler errors, and I'm not sure why. What am I doing wrong here: Hangman.cpp: set<char> Hangman::incorrectGuesses() { // Hangman line 103 return Utils::findAll_if<char>(guesses.begin(), guesses.end(), &Hangman::isIncorrectGuess); } bool Hangman::isIncorrectGuess(char c) { return correctAnswer.find(c) == string::npos; } Utils.h: namespace Utils { void PrintLine(const string& line, int tabLevel = 0); string getTabs(int tabLevel); template<class result_t, class Predicate> std::set<result_t> findAll_if(typename std::set<result_t>::iterator begin, typename std::set<result_t>::iterator end, Predicate pred) { std::set<result_t> result; // utils line 16 return detail::findAll_if_rec<result_t>(begin, end, pred, result); } } namespace detail { template<class result_t, class Predicate> std::set<result_t> findAll_if_rec(typename std::set<result_t>::iterator begin, typename std::set<result_t>::iterator end, Predicate pred, std::set<result_t> result) { // utils line 25 typename std::set<result_t>::iterator nextResultElem = find_if(begin, end, pred); if (nextResultElem == end) { return result; } result.insert(*nextResultElem); return findAll_if_rec(++nextResultElem, end, pred, result); } } This produces the following compiler errors: algorithm(83): error C2064: term does not evaluate to a function taking 1 arguments algorithm(95) : see reference to function template instantiation '_InIt std::_Find_if<std::_Tree_unchecked_const_iterator<_Mytree>,_Pr>(_InIt,_InIt,_Pr)' being compiled 1> with 1> [ 1> _InIt=std::_Tree_unchecked_const_iterator<std::_Tree_val<std::_Tset_traits<char,std::less<char>,std::allocator<char>,false>>>, 1> _Mytree=std::_Tree_val<std::_Tset_traits<char,std::less<char>,std::allocator<char>,false>>, 1> _Pr=bool (__thiscall Hangman::* )(char) 1> ] utils.h(25) : see reference to function template instantiation '_InIt std::find_if<std::_Tree_const_iterator<_Mytree>,Predicate>(_InIt,_InIt,_Pr)' being compiled 1> with 1> [ 1> _InIt=std::_Tree_const_iterator<std::_Tree_val<std::_Tset_traits<char,std::less<char>,std::allocator<char>,false>>>, 1> _Mytree=std::_Tree_val<std::_Tset_traits<char,std::less<char>,std::allocator<char>,false>>, 1> Predicate=bool (__thiscall Hangman::* )(char), 1> _Pr=bool (__thiscall Hangman::* )(char) 1> ] utils.h(16) : see reference to function template instantiation 'std::set<_Kty> detail::findAll_if_rec<result_t,Predicate>(std::_Tree_const_iterator<_Mytree>,std::_Tree_const_iterator<_Mytree>,Predicate,std::set<_Kty>)' being compiled 1> with 1> [ 1> _Kty=char, 1> result_t=char, 1> Predicate=bool (__thiscall Hangman::* )(char), 1> _Mytree=std::_Tree_val<std::_Tset_traits<char,std::less<char>,std::allocator<char>,false>> 1> ] hangman.cpp(103) : see reference to function template instantiation 'std::set<_Kty> Utils::findAll_if<char,bool(__thiscall Hangman::* )(char)>(std::_Tree_const_iterator<_Mytree>,std::_Tree_const_iterator<_Mytree>,Predicate)' being compiled 1> with 1> [ 1> _Kty=char, 1> _Mytree=std::_Tree_val<std::_Tset_traits<char,std::less<char>,std::allocator<char>,false>>, 1> Predicate=bool (__thiscall Hangman::* )(char) 1> ]

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  • Assigning a value to a variable gets stored in the wrong spot?

    - by scribbloid
    Hello, I'm relatively new to C, and this is baffling me right now. It's part of a much larger program, but I've written this little program to depict the problem I'm having. #include <stdio.h> int main() { signed int tcodes[3][1]; tcodes[0][0] = 0; tcodes[0][1] = 1000; tcodes[1][0] = 1000; tcodes[1][1] = 0; tcodes[2][0] = 0; tcodes[2][1] = 1000; tcodes[3][0] = 1000; tcodes[3][1] = 0; int x, y, c; for(c = 0; c <= 3; c++) { printf("%d %d %d\r\n", c, tcodes[c][0], tcodes[c][1]); x = 20; y = 30; } } I'd expect this program to output: 0 0 1000 1 1000 0 2 0 1000 3 1000 0 But instead, I get: 0 0 1000 1 1000 0 2 0 20 3 20 30 It does this for any number assigned to x and y. For some reason x and y are overriding parts of the array in memory. Can someone explain what's going on? Thanks!

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  • PHP Using session variables in array(s)

    - by Chris
    Hello, My question is how do i put these session variables into a array? I have tried countless ways but none of them work. Not really sure what to put in a array and what no and how to adress them. Currently when i fill in the form the data gets displayed in a table. Next when i press the hyperlink that takes me back to the same form, i wish to enter data again. This data should be added in a new row in the same display table. Best Regards. The code below (pardon me that it is not english). <?php session_start(); ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-Strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>ExpoFormulier</title> <body> <?php if (!empty($_POST)) { $standnaam = $_POST["standnaam"]; $oppervlakte = $_POST["oppervlakte"]; //value in the form van checkboxes op 1 zetten! $verdieping = isset($_POST["verdieping"]) ? $_POST["verdieping"] : 0; $telefoon = isset($_POST["telefoon"]) ? $_POST["telefoon"] : 0; $netwerk = isset($_POST["netwerk"]) ? $_POST["netwerk"] : 0; if (is_numeric($oppervlakte)) { $_SESSION["standnaam"]=$standnaam; $_SESSION["oppervlakte"]=$oppervlakte; $_SESSION["verdieping"]=$verdieping; $_SESSION["telefoon"]=$telefoon; $_SESSION["netwerk"]=$netwerk; header("Location:ExpoOverzicht.php"); } else { echo "<h1>Foute gegevens, Opnieuw invullen a.u.b</h1>"; } } ?> <form action="<?php echo $_SERVER["PHP_SELF"]; ?>" method="post" id="form1"> <h1>Vul de gegevens in</h1> <table> <tr> <td>Standnaam:</td> <td><input type="text" name="standnaam" size="18"/></td> </tr> <tr> <td>Oppervlakte (in m^2):</td> <td><input type="text" name="oppervlakte" size="6"/></td> </tr> <tr> <td>Verdieping:</td> <td><input type="checkbox" name="verdieping" value="1"/></td> </tr> <tr> <td>Telefoon:</td> <td><input type="checkbox" name="telefoon" value="1"/></td> </tr> <tr> <td>Netwerk:</td> <td><input type="checkbox" name="netwerk" value="1"/></td> </tr> <tr> <td><input type="submit" name="verzenden" value="Verzenden"/></td> </tr> </table> </form> Second File: <?php session_start(); ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-Strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>ExpoOverzicht</title> <meta http-equiv="content-type" content="text/html; charset=utf-8" /> <link href="StyleSheetExpo.css" rel="stylesheet" type="text/css" /> </head> <body> <h1>Overzicht van de ingegeven standen in deze sessie</h1> <?php $standnaam = $_SESSION["standnaam"]; $oppervlakte = $_SESSION["oppervlakte"]; $verdieping = $_SESSION["verdieping"]; $telefoon = $_SESSION["telefoon"]; $netwerk = $_SESSION["netwerk"]; $result1 = 0; $result2 = 0; $result3 = 0; $prijsCom = 0; $prijsVerdieping = 0; for ($i=1; $i <= $oppervlakte; $i++) { if($i <= 10) { $tarief1 = 1 * 100; $result1 += $tarief1; } if($i > 10 && $i <= 30) { $tarief2 = 1 * 90; $result2 += $tarief2; } if($i > 30) { $tarief3 = 1 * 80; $result3 += $tarief3; } } $prijsOpp = $result1 + $result2 + $result3; if($verdieping == 1) { $prijsVerdieping = $oppervlakte * 120; } if(($telefoon == 1) || ($netwerk == 1)) { $prijsCom = 20; } if(($telefoon == 1) && ($netwerk == 1)) { $prijsCom = 30; } $totalePrijs = $prijsOpp + $prijsVerdieping + $prijsCom; echo "<table class=\"tableExpo\">"; echo "<th>Standnaam</th>"; echo "<th>Oppervlakte</th>"; echo "<th>Verdieping</th>"; echo "<th>Telefoon</th>"; echo "<th>Netwerk</th>"; echo "<th>Totale prijs</th>"; echo "<tr>"; echo "<td>".$standnaam."</td>"; echo "<td>".$oppervlakte."</td>"; echo "<td>".$verdieping."</td>"; echo "<td>".$telefoon."</td>"; echo "<td>".$netwerk."</td>"; echo "<td>".$totalePrijs."</td>"; echo "</tr>"; echo "</table>"; ?> <a href="ExpoFormulier.php">Terug naar het formulier</a> </body> </html> </body> </html>

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  • How do I create an NSArray with string literals?

    - by Kyle
    I'm attempting to create an NSArray with a grouping of string literals, however I get the compile error "Initializer element is not constant". NSArray *currencies = [NSArray arrayWithObjects:@"Dollar", @"Euro", @"Pound", nil]; Could someone point out what I'm doing wrong, and possibly explain the error message?

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  • TB3.0.10: Messages being sent back to me

    - by punkinette64
    Hello, I don't know if this will make any sense to you; but here goes. When I send an email and I get a response, more often than not, in the 'to:' is my email address. However, my email address also ends up in the 'from' column.The 'reply-from' address is nowhere to be found;so I don't have any address with which I can send my reply, as both of them have just my email address. What am I doing wrong here? Is there some set-up in my TOOLOPTIONS set-up incorrectly? The set-up in OPTIONS is pretty difficult to understand and it doesn't offer any 'to' or 'reply-from' choices. This is critical because I just cannot answer my emails because there is no one I can send a reply to. Please, please try to help me. If you have the answer, please email me at: [email protected] Thank you. Blessings. Shiloh

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  • passing a class method as opposed to a function in std::sort

    - by memC
    hi, Within a class, I am trying to sort a vector, by passing a method of the same class. But it gives errors at the time of compilation. Can anyone tell what the problem is? Thank you! it gives the following error: argument of type bool (Sorter::)(D&, D&)' does not matchbool (Sorter::*)(D&, D&)' I have also tried using sortBynumber(D const& d1, D const& d2) #include<vector> #include<stdio.h> #include<iostream> #include<algorithm> class D { public: int getNumber(); D(int val); ~D(){}; private: int num; }; D::D(int val){ num = val; }; int D::getNumber(){ return num; }; class Sorter { public: void doSorting(); bool sortByNumber(D& d1, D& d2); std::vector<D> vec_D; Sorter(); ~Sorter(){}; private: int num; }; Sorter::Sorter(){ int i; for ( i = 0; i < 10; i++){ vec_D.push_back(D(i)); } }; bool Sorter::sortByNumber(D& d1, D& d2){ return d1.getNumber() < d2.getNumber(); }; void Sorter::doSorting(){ std::sort(vec_D.begin(), vec_D.end(), this->sortByNumber); }; int main(){ Sorter s; s.doSorting(); std::cout << "\nPress RETURN to continue..."; std::cin.get(); return 0; }

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  • How to get global access to enum types in C#?

    - by lala
    This is probably a stupid question, but I can't seem to do it. I want to set up some enums in one class like this: public enum Direction { north, east, south, west }; Then have that enum type accessible to all classes so that some other class could for instance have: Direction dir = north; and be able to pass the enum type between classes: public void changeDirection(Direction direction) { dir = direction; } I thought that setting the enum to public would make this automatically possible, but it doesn't seem to be visible outside of the class I declared the enum in.

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  • How can I know whether my C++ string variable is a number or not

    - by user342580
    I have a string of class string string str; how can I check if it is a number or not, str can only have 3 possible types described below like abcd or a number like 123.4 or a number with a parenthesis attach to the end it for example 456) note the parenthesis at the end of "str" is the only possible combination of number and none number where the bottom two are considered valid numbers, I know I could use lexical_cast if only the first 2 cases occur, but how about considering all 3 possible cases to occur? I don't need to do anything fancy with str, I just need to know whether it is a valid number as I described

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