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  • returning reference to a vector from a method and using its public members

    - by memC
    dear experts, I have a vector t_vec that stores references to instances of class Too. The code is shown below. In the main , I have a vector t_vec_2 which has the same memory address as B::t_vec. But when I try to access t_vec_2[0].val1 it gives error val1 not declared. Could you please point out what is wrong? Also, if you know of a better way to return a vector from a method, please let me know! Thanks in advance. class Too { public: Too(); ~Too(){}; int val1; }; Too::Too(){ val1 = 10; }; class B { public: vector<Too*> t_vec; Too* t1; vector<Too*>& get_tvec(); B(){t1 = new Too();}; ~B(){delete t1;}; }; vector<Too*>& B::get_tvec(){ t_vec.push_back(t1); return t_vec; } int main(){ B b; b = B(); vector<Too*>& t_vec_2 = b.get_tvec(); // Getting error std::cout << "\n val1 = " << t_vec_2[0].val1; return 0; }

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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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  • How to create conditions in mysql (use of 'if')?

    - by Audel
    This code works fine to find an available room within certain date, but it does not work to show a room that has been booked and canceled The "hotel" has 4 rooms and 1 of them has been booked an canceled So even if I make a cancelation, the select method keeps giving me 3 results. Maybe because the second AND is still running. So basically what I need is check if the room is booked in the selected dates if it has been booked, check if its canceled if it has been canceled, or not booked display it. Otherwise not   SELECT RoomNo, NightCost FROM room, room_types, booking WHERE typeid = fk1_typeid and double_bed=1 and single_bed=0 AND canceled = '1' in (SELECT canceled from booking, room_booking where bookingid = fk2_bookingid) AND RoomNo not in (SELECT fk1_RoomNo FROM room_booking WHERE '2010-04-02' between Check_in and Check_Out or '2010-04-03' between Check_in and Check_Out) ; I tried to be as clear as possible, i will be around to give more details if needed

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  • JavaScript: How is "function x() {}" different from "x = function() {}" ?

    - by jleedev
    In the answers to this question, we read that function f() {} defines the name locally, while [var] f = function() {} defines it globally. That makes perfect sense to me, but there's some strange behavior that's different between the two declarations. I made an HTML page with the script onload = function() { alert("hello"); } and it worked as expected. When I changed it to function onload() { alert("hello"); } nothing happened. (Firefox still fired the event, but WebKit, Opera, and Internet Explorer didn't, although frankly I've no idea which is correct.) In both cases (in all browsers), I could verify that both window.onload and onload were set to the function. In both cases, the global object this is set to the window, and I no matter how I write the declaration, the window object is receiving the property just fine. What's going on here? Why does one declaration work differently from the other? Is this a quirk of the JavaScript language, the DOM, or the interaction between the two?

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  • Adding li element only if it not already there?

    - by Legend
    I am constructing an <li> element like this: var element = $("<li></li>") .html(mHTML) .attr('id', "elemid"); I am trying to add this element to a <ul> element only if it doesn't already exist. Any ideas on how to do this? Am I supposed to use contains() to see if the ul element contain the html and then decide? For instance, <ul id="elemul"> <li id="elemli1">Element 1</li> <li id="elemli2">Element 2</li> <li id="elemli3">Element 3</li> </ul> If I try adding Element 1, it should not add it. What should I do if its a longer string (not really long but about 150 characters). Note: I cannot rely on IDs to determine the uniqueness. i.e. I might end up forming something like: <li id="elemli3">Element 1</li> Do I go about using hashmaps?

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  • JButtons re-enable themselves after being disabled

    - by Anarchist
    I have an array of JButtons which form a keypad interface. After six numbers are entered I want to disable the keypad so that no further numbers can be entered by the user. I have written the code and the buttons do disable until the mouse hovers above any of them, then the buttons seem to re-enable themselves and run actionEvents added to them. The full code is available here. Possible things that I think are wrong. There is some sort of MouseListener which is ignoring when I set button.setEnabled(false); I haven't separated attributes from the buildGUI(); correctly, I only did this anyway so that the inner class could access them. Possibly something to do with the gridLayout as disabling the buttons seems to work for my services JPanel buttons.

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  • Python integer incrementing with ++

    - by Znarkus
    I've always laughed to myself when I looked back at my VB6 days, "What modern language doesn't allow incrementing with double plus signs?": number++ To my surprise I can't find anything about this in the Python docs. Must I really subject myself to number = number + 1? Doesn't people use the ++/-- notation? :-(

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  • Help C++ifying this C style code.

    - by Flamewires
    Hey I'm used to developing in C and I would like to use C++ in a project. Can anyone give me an example of how I would translate this C-style code into C++ code. I know it should compile in a c++ complier but I'm talking using c++ techniques(I.e. classes, RAII) typedef struct Solution Solution; struct Solution { double x[30]; int itt_found; double value; }; Solution *NewSolution() { Solution *S = (Solution *)malloc(sizeof(Solution)); for (int i=0;<=30;i++) { S-x[i] = 0; } S-itt_found = -1; return S; } void FreeSolution(Solution *S) { if (S != NULL) free(S); } int main() { Solution *S = NewSolution(); S-value = eval(S-x);// evals is another function that returns a double S-itt_found = 0; FreeSolution(S); return EXIT_SUCCESS; } Ideally I would like to be able to so something like this in main, but I'm not sure exactly how to create the class, i've read a lot of stuff but incorporating it all together correctly seems a little hard atm. Solution S(30);//constructor that takes as an argument the size of the double array S.eval();//a method that would run eval on S.x[] and store result in S.value cout << S.value << endl; Ask if you need more info, thanks.

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  • Understanding CGI and SQL security from the ground up

    - by Steve
    This question is for learning purposes. Suppose I am writing a simple SQL admin console using CGI and Python. At http://something.com/admin, this admin console should allow me to modify a SQL database (i.e., create and modify tables, and create and modify records) using an ordinary form. In the least secure case, anybody can access http://something.com/admin and modify the database. You can password protect http://something.com/admin. But once you start using the admin console, information is still transmitted in plain text. So then you use HTTPS to secure the transmitted data. Questions: To describe to a learner, how would you incrementally add security to the least secure environment in order to make it most secure? How would you modify/augment my three (possibly erroneous) steps above? What basic tools in Python make your steps possible? Optional: Now that I understand the process, how do sophisticated libraries and frameworks inherently achieve this level of security?

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  • Filter some words

    - by bob
    I want to filter some reserved word on my title form. $adtitle = sanitize($_POST['title']); $ignore = array('sale','buy','rent'); if(in_array($adtitle, $ignore)) { $_SESSION['ignore_error'] = '<strong>'.$adtitle.'</strong> cannot be use as your title'; header('Location:/submit/'); exit; How to make something like this. If user type Car for sale the sale will detected as reserved keyword. Now my current code only detect single keyword only.

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  • Strange Access Denied warning when running the simplest C++ program.

    - by DaveJohnston
    I am just starting to learn C++ (coming from a Java background) and I have come across something that I can't explain. I am working through the C++ Primer book and doing the exercises. Every time I get to a new exercise I create a new .cpp file and set it up with the main method (and any includes I think I will need) e.g.: #include <list> #include <vector> int main(int argc, char **args) { } and just to make sure I go to the command prompt and compile and run: g++ whatever.cpp a.exe Normally this works just fine and I start working on the exercise, but I just did it and got a strange error. It compiles fine, but when I run it it says Access Denied and AVG pops up telling me that a threat has been detected 'Trojan Horse Generic 17.CKZT'. I tried compiling again using the Microsoft Compiler (cl.exe) and it runs fines. So I went back, and added: #include <iostream> compiled using g++ and ran. This time it worked fine. So can anyone tell me why AVG would report an empty main method as a trojan horse but if the iostream header is included it doesn't?

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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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  • What is mod_php...?

    - by SpikETidE
    Hi everybody... First of all, Pardon this complete n00b question... While going through the zend tutorial here i came across the following statement... Note that the php_flag settings in .htaccess only work if you are using mod_php. Can someone explain what that means...??? Thanks and Regards....

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