Search Results

Search found 1591 results on 64 pages for 'oop criticism'.

Page 23/64 | < Previous Page | 19 20 21 22 23 24 25 26 27 28 29 30  | Next Page >

  • Loose Coupling of Components

    - by David
    I have created a class library (assembly) that provides messaging, email and sms. This class library defines an interface IMessenger which the classes EmailMessage and SmsMessage both implement. I see this is a general library that would be part of my infrastructure layer and would / can be used across any development. Now, in my application layer I have a class that requires to use a messaging component, I obviously want to use the messaging library that I have created. Additionally, I will be using an IoC container (Spring.net) to allow me to inject my implementation i.e. either email or sms. Therefore, I want to program against an interface in my application layer class, do I then need to reference my message class library from my application layer class? Is this tightly coupling my application layer class to my message class library? Should I be defining the interface - IMessenger in a seperate library? Or should I be doing something else?

    Read the article

  • Question about decorator pattern and the abstract decorator class?

    - by es11
    This question was asked already here, but rather than answering the specific question, descriptions of how the decorator pattern works were given instead. I'd like to ask it again because the answer is not immediately evident to me just by reading how the decorator pattern works (I've read the wikipedia article and the section in the book Head First Design Patterns). Basically, I want to know why an abstract decorator class must be created which implements (or extends) some interface (or abstract class). Why can't all the new "decorated classes" simply implement (or extend) the base abstract object themselves (instead of extending the abstract decorator class)? To make this more concrete I'll use the example from the design patterns book dealing with coffee beverages: There is an abstract component class called Beverage Simple beverage types such as HouseBlend simply extend Beverage To decorate beverage, an abstract CondimentDecorator class is created which extends Beverage and has an instance of Beverage Say we want to add a "milk" condiment, a class Milk is created which extends CondimentDecorator I'd like to understand why we needed the CondimentDecorator class and why the class Milk couldn't have simply extended the Beverage class itself and been passed an instance of Beverage in its constructor. Hopefully this is clear...if not I'd simply like to know why is the abstract decorator class necessary for this pattern? Thanks. Edit: I tried to implement this, omitting the abstract decorator class, and it seems to still work. Is this abstract class present in all descriptions of this pattern simply because it provides a standard interface for all of the new decorated classes?

    Read the article

  • Use string value to create new instance

    - by Brian David Berman
    I have a few classes: SomeClass1, SomeClass2. How can I create a new instance of one of these classes by using the class name from a string? Normally, I would do: var someClass1 = new SomeClass1(); How can I create this instance from the following: var className = "SomeClass1"; I am assuming I should use Type.GetType() or something but I can't figure it out. Thanks.

    Read the article

  • Auto-implemented getters and setters vs. public fields

    - by tclem
    I see a lot of example code for C# classes that does this: public class Point { public int x { get; set; } public int y { get; set; } } Or, in older code, the same with an explicit private backing value and without the new auto-implemented properties: public class Point { private int _x; private int _y; public int x { get { return _x; } set { _x = value; } } public int y { get { return _y; } set { _y = value; } } } My question is why. Is there any functional difference between doing the above and just making these members public fields, like below? public class Point { public int x; public int y; } To be clear, I understand the value of getters and setters when you need to do some translation of the underlying data. But in cases where you're just passing the values through, it seems needlessly verbose.

    Read the article

  • wrapping aspx user controls commands in a transaction

    - by Hans Gruber
    I'm working on heavily dynamic and configurable CMS system. Therefore, many pages are composed of a dynamically loaded set of user controls. To enable loose coupling between containers (pages) and children (user controls), all user controls are responsible for their own persistence. Each User Control is wired up to its data/service layer dependencies via IoC. They also implement an IPersistable interface, which allows the container .aspx page to issue a Save command to its children without knowledge of the number or exact nature of these user controls. Note: what follows is only pseudo-code: public class MyUserControl : IPersistable, IValidatable { public void Save() { throw new NotImplementedException(); } public bool IsValid() { throw new NotImplementedException(); } } public partial class MyPage { public void btnSave_Click(object sender, EventArgs e) { foreach (IValidatable control in Controls) { if (!control.IsValid) { throw new Exception("error"); } } foreach (IPersistable control in Controls) { if (!control.Save) { throw new Exception("error"); } } } } I'm thinking of using declarative transactions from the System.EnterpriseService namespace to wrap the btnSave_Click in a transaction in case of an exception, but I'm not sure how this might be achieved or any pitfalls to such an approach.

    Read the article

  • Turning PHP page calling Zend functions procedurally into Zend Framework MVC-help!

    - by Joel
    Hi guys, I posted much of this question, but if didn't include all the Zend stuff because I thought it'd be overkill, but now I'm thinking it's not easy to figure out an OO way of doing this without that code... So with that said, please forgive the verbose code. I'm learning how to use MVC and OO in general, and I have a website that is all in PHP but most of the pages are basic static pages. I have already converted them all to views in Zend Framework, and have the Controller and layout set. All is good there. The one remaining page I have is the main reason I did this...it in fact uses Zend library (for gData connection and pulling info from a Google Calendar and displaying it on the page. I don't know enough about this to know where to begin to refactor the code to fit in the Zend Framework MVC model. Any help would be greatly appreciated!! .phtml view page: <div id="dhtmltooltip" align="left"></div> <script src="../js/tooltip.js" type="text/javascript"> </script> <div id="container"> <div id="conten"> <a name="C4"></a> <?php function get_desc_second_part(&$value) { list(,$val_b) = explode('==',$value); $value = trim($val_b); } function filterEventDetails($contentText) { $data = array(); foreach($contentText as $row) { if(strstr($row, 'When: ')) { ##cleaning "when" string to get date in the format "May 28, 2009"## $data['duration'] = str_replace('When: ','',$row); list($when, ) = explode(' to ',$data['duration']); $data['when'] = substr($when,4); if(strlen($data['when'])>13) $data['when'] = trim(str_replace(strrchr($data['when'], ' '),'',$data['when'])); $data['duration'] = substr($data['duration'], 0, strlen($data['duration'])-4); //trimming time zone identifier (UTC etc.) } if(strstr($row, 'Where: ')) { $data['where'] = str_replace('Where: ','',$row); //pr($row); //$where = strstr($row, 'Where: '); //pr($where); } if(strstr($row, 'Event Description: ')) { $event_desc = str_replace('Event Description: ','',$row); //$event_desc = strstr($row, 'Event Description: '); ## Filtering event description and extracting venue, ticket urls etc from it. //$event_desc = str_replace('Event Description: ','',$contentText[3]); $event_desc_array = explode('|',$event_desc); array_walk($event_desc_array,'get_desc_second_part'); //pr($event_desc_array); $data['venue_url'] = $event_desc_array[0]; $data['details'] = $event_desc_array[1]; $data['tickets_url'] = $event_desc_array[2]; $data['tickets_button'] = $event_desc_array[3]; $data['facebook_url'] = $event_desc_array[4]; $data['facebook_icon'] = $event_desc_array[5]; } } return $data; } // load library require_once 'Zend/Loader.php'; Zend_Loader::loadClass('Zend_Gdata'); Zend_Loader::loadClass('Zend_Gdata_ClientLogin'); Zend_Loader::loadClass('Zend_Gdata_Calendar'); Zend_Loader::loadClass('Zend_Http_Client'); // create authenticated HTTP client for Calendar service $gcal = Zend_Gdata_Calendar::AUTH_SERVICE_NAME; $user = "[email protected]"; $pass = "xxxxxxxx"; $client = Zend_Gdata_ClientLogin::getHttpClient($user, $pass, $gcal); $gcal = new Zend_Gdata_Calendar($client); $query = $gcal->newEventQuery(); $query->setUser('[email protected]'); $secondary=true; $query->setVisibility('private'); $query->setProjection('basic'); $query->setOrderby('starttime'); $query->setSortOrder('ascending'); //$query->setFutureevents('true'); $startDate=date('Y-m-d h:i:s'); $endDate="2015-12-31"; $query->setStartMin($startDate); $query->setStartMax($endDate); $query->setMaxResults(30); try { $feed = $gcal->getCalendarEventFeed($query); } catch (Zend_Gdata_App_Exception $e) { echo "Error: " . $e->getResponse(); } ?> <h1><?php echo $feed->title; ?></h1> <?php echo $feed->totalResults; ?> event(s) found. <table width="90%" border="3" align="center"> <tr> <td width="20%" align="center" valign="middle"><b>;DATE</b></td> <td width="25%" align="center" valign="middle"><b>VENUE</b></td> <td width="20%" align="center" valign="middle"><b>CITY</b></td> <td width="20%" align="center" valign="middle"><b>DETAILS</b></td> <td width="15%" align="center" valign="middle"><b>LINKS</b></td> </tr> <?php if((int)$feed->totalResults>0) { //checking if at least one event is there in this date range foreach ($feed as $event) { //iterating through all events //pr($event);die; $contentText = stripslashes($event->content->text); //striping any escape character $contentText = preg_replace('/\<br \/\>[\n\t\s]{1,}\<br \/\>/','<br />',stripslashes($event->content->text)); //replacing multiple breaks with a single break //die(); $contentText = explode('<br />',$contentText); //splitting data by break tag $eventData = filterEventDetails($contentText); $when = $eventData['when']; $where = $eventData['where']; $duration = $eventData['duration']; $venue_url = $eventData['venue_url']; $details = $eventData['details']; $tickets_url = $eventData['tickets_url']; $tickets_button = $eventData['tickets_button']; $facebook_url = $eventData['facebook_url']; $facebook_icon = $eventData['facebook_icon']; $title = stripslashes($event->title); echo '<tr>'; echo '<td width="20%" align="center" valign="middle" nowrap="nowrap">'; echo $when; echo '</td>'; echo '<td width="20%" align="center" valign="middle">'; if($venue_url!='') { echo '<a href="'.$venue_url.'" target="_blank">'.$title.'</a>'; } else { echo $title; } echo '</td>'; echo '<td width="20%" align="center" valign="middle">'; echo $where; echo '</td>'; echo '<td width="20%" align="center" valign="middle">'; $details = str_replace("\n","<br>",htmlentities($details)); $duration = str_replace("\n","<br>",$duration); $detailed_description = "<b>When</b>: <br>".$duration."<br><br>"; $detailed_description .= "<b>Description</b>: <br>".$details; echo '<a href="javascript:void(0);" onmouseover="ddrivetip(\''.$detailed_description.'\')" onmouseout="hideddrivetip()" onclick="return false">View Details</a>'; echo '</td>'; echo '<td width="20%" valign="middle">'; if(trim($tickets_url) !='' && trim($tickets_button)!='') { echo '<a href="'.$tickets_url.'" target="_blank"><img src="'.$tickets_button.'" border="0" ></a>'; } if(trim($facebook_url) !='' && trim($facebook_icon)!='') { echo '<a href="'.$facebook_url.'" target="_blank"><img src="'.$facebook_icon.'" border="0" ></a>'; } else { echo '......'; } echo '</td>'; echo '</tr>'; } } else { //else show 'no event found' message echo '<tr>'; echo '<td width="100%" align="center" valign="middle" colspan="5">'; echo "No event found"; echo '</td>'; } ?> </table> <h3><a href="#pastevents">Scroll down for a list of past shows.</a></h3> <br /> <a name="pastevents"></a> <ul class="pastShows"> <?php $startDate='2005-01-01'; $endDate=date('Y-m-d'); /*$gcal = Zend_Gdata_Calendar::AUTH_SERVICE_NAME; $user = "[email protected]"; $pass = "silverroof10"; $client = Zend_Gdata_ClientLogin::getHttpClient($user, $pass, $gcal); $gcal = new Zend_Gdata_Calendar($client); $query = $gcal->newEventQuery(); $query->setUser('[email protected]'); $query->setVisibility('private'); $query->setProjection('basic');*/ $query->setOrderby('starttime'); $query->setSortOrder('descending'); $query->setFutureevents('false'); $query->setStartMin($startDate); $query->setStartMax($endDate); $query->setMaxResults(1000); try { $feed = $gcal->getCalendarEventFeed($query); } catch (Zend_Gdata_App_Exception $e) { echo "Error: " . $e->getResponse(); } if((int)$feed->totalResults>0) { //checking if at least one event is there in this date range foreach ($feed as $event) { //iterating through all events $contentText = stripslashes($event->content->text); //striping any escape character $contentText = preg_replace('/\<br \/\>[\n\t\s]{1,}\<br \/\>/','<br />',stripslashes($event->content->text)); //replacing multiple breaks with a single break $contentText = explode('<br />',$contentText); //splitting data by break tag $eventData = filterEventDetails($contentText); $when = $eventData['when']; $where = $eventData['where']; $duration = $eventData['duration']; $title = stripslashes($event->title); echo '<li class="pastShows">' . $when . " - " . $title . ", " . $where . '</li>'; } } ?> </div> </div>

    Read the article

  • Lightweight PHP library alternative to common MVC frameworks

    - by artarad
    Hi hi, I'm looking for a easy to learn php library to use for my coming web app project. I've recently finished a web app with fully handwritten raw php code and it's absolutely hard to be done again for another project. even though I have the recent project code snippets to be used again, but due to their non-structural arrangement (not object oriented), i have no passion to use 'em again. I have no experience with common frameworks like ZF, CakePhp, CodeIgniter, so I think to get my hands on a multipurpose OO library for my web app and the framework learning will be the next step! any suggestion? UPDATE: Many thanks guys, I have not enough time to get through the depth of every lib or framework you have kindly introduced. Since I'm going one step further I'm going to use ZF as famous framework which could provide me more job opportunities perhaps. thankssss :)

    Read the article

  • Placement of a call to the parent method

    - by Alejandro
    I have a class that has a method. That class has a child class that overrides that method. The child's method has to call the parent's method. In all OO that I've seen or written calls to the parent's version of the same method were on the first line of the method. On a project that I am working on circumstances call for placing that method call at the end of a method. Should I be worried? Is that a code smell? Is this code inherently bad? class Parent { function work() { // stuff } } class Child { function work() { // do thing 1 // do thing 2 parent::work(); // is this a bad practice? // should I call the parent's work() method before // I do anything in this method? } }

    Read the article

  • My first c# app and first null object exception

    - by Fresheyeball
    Total noob here. This is my first c# attempt, its a console application that simulates a drinking game called 'Left Right Center'. In the console I receive the following: CONSOLE Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object at LeftRightCenter.MainClass.Main (System.String[] args) [0x00038] in /Users/apple/Projects/LearningC/LearningC/Main.cs:80 [ERROR] FATAL UNHANDLED EXCEPTION: System.NullReferenceException: Object reference not set to an instance of an object at LeftRightCenter.MainClass.Main (System.String[] args) [0x00038] in /Users/apple/Projects/LearningC/LearningC/Main.cs:80 C# using System; namespace LeftRightCenter { class Player { //fields private int _quarters = 4; public int Quarters { get{ return _quarters; } set{ _quarters += value; } } public Player (string name) { } } class Dice { Random random = new Random(); public int Roll () { random = new Random (); int diceSide; diceSide = random.Next (0, 6); diceSide = (diceSide > 2) ? 3 : diceSide; return diceSide; } } class MainClass { static int activePlayer = 0; static int theCup = 0; static Player[] thePlayers = { new Player ("Jessica"), new Player ("Isaac"), new Player ("Ed"), new Player ("Bella"), new Player ("Elisa"), new Player ("Fake RedHead"), new Player ("Linda"), new Player ("MJ"), new Player ("Irene"), new Player("Devin") }; static Dice[] theDice = new Dice[2]; private static void MoveQuarter (int direction) { int numberOfPlayers = thePlayers.Length - 1; switch (direction) { case 0: thePlayers [activePlayer].Quarters = -1; theCup++; break; case 1: thePlayers [activePlayer].Quarters = -1; int leftPlayer = (activePlayer == 0) ? numberOfPlayers : activePlayer - 1; thePlayers [leftPlayer].Quarters = +1; break; case 2: thePlayers [activePlayer].Quarters = -1; int rightPlayer = (activePlayer == numberOfPlayers) ? 0 : activePlayer + 1; thePlayers [rightPlayer].Quarters = +1; break; } } public static void Main (string[] args) { int cupEndPoint = thePlayers.Length * 4 - 1; while (theCup < cupEndPoint) { foreach (Dice rattle in theDice) { if (thePlayers [activePlayer].Quarters > 0) { MoveQuarter (rattle.Roll ()); // this line seems to be the problem } } Console.WriteLine ("{0} Quarters In the Cup", theCup); } } } } I have no idea what the problem is or why, and my googling have proven more use confusing than helpful.

    Read the article

  • GUI system architecture?

    - by topright
    I'm designing GUI (graphical user interface) system for a game engine (C++). Idea is to create a heirarchy of GUI controllers like Focusable, Hoverable, Dragable etc. Every GUI component can attach multiple controllers, they modify component's behaviour. I think it gives flexible system and protects from code duplication. Different instances of the same GUI class can have different complex behaviours (may be, even change it dynamically), so this approach looks practical. The other choice is to add focused, hovered, dragged etc. flags in the base GUI component class. It looks like overhead and not that flexible. Another solution is to use Decorator pattern and wrap objects with FocusDecorator, HoverDecorator etc. Maintaining such system looks a bit harder. Question: What are pitfalls in my solution? May be you have seen a better approaches in GUI systems? What are the best ways of implementing such flexible complex system?

    Read the article

  • A Question on Encapsulation.

    - by Bragaadeesh
    Hi, I know that encapsulation is binding the members and its behavior in one single entity. And it has made me think that the members have to be private. Does this mean if a class having public members is not following 100% Encapsulation rule? Thanks

    Read the article

  • Modelling multiple simultaneous states

    - by James P.
    How can you go about modelling an object that can have multiple simultaneous states? For example, you could have a person that's waiting for a bus. That's one state. But they could also be reading a newspaper while waiting for the bus. Furthermore, they could be thinking about something while reading the newspaper. They could also be sniffing their nose because they have a cold. That's a four states in all taking place at the same time. Obviously using booleans would be tedious and unflexible. Also, a conventional state pattern would mean that states are exclusive and can't be simultaneous in nature. The only thing I can think of is a State pattern combined with a Composite. Would this do or is there a way of taking things further?

    Read the article

  • How to make some functions of a class as private for third level of inheritance.

    - by Shantanu Gupta
    I have created a class say A which has some functions defined as protected. Now Class B inherits A and class C inherits B. Class A has private default constructor and protected parameterized constructor. I want Class B to be able to access all the protected functions defined in Class A but class C can have access on some of the functions only not all the functions and class C is inheriting class B. How can I restrict access to some of the functions of Class A from Class C ? Class A { private A(){} protected A(int ){} protected calc(){} protected allow(){} } Class B : A {} // calc() and allow() should be accessible here CLass C:B { // calc() should not be accessible here but allow() should be accessible here. }

    Read the article

  • Properly design a code editor application

    - by Hemaulo
    I'm working on personal project which is basically a code editor. Imagine standard File menu with menu items New, Open, Save, Save As, Save All, Close, Close All. I'm stuck with proper design. Currently I have: A Document class which represents a document - code editing control, respective tab in tab bar and various properties such as Caption, Filename, IsModified etc. A Documents class which represents all open documents. Contains methods like New, Open(FileName), ... The problem is that I can't figure out which class / menu command is responsible for which tasks. For example, with File-New menu command is simple - call Documents.New and that's it. But what for File-Open? The Documents.Open method expects filename as a parameter. So before calling this method I need to open an file selection dialog, let user select files and for each file call Documents.Open(FileName). Where is best place for this supporting code, in menu command, rewrite Documents.Open and put it there? The same with Save actions. Which is responsible for saving? Is it Documents class which uses Document.Editor.SaveToFile(FileName) or better create Save method in Document class? Somewhere in the middle also need to ask user if he wants to save current document... I'm stuck. Any ideas? Edited: The programming language is Delphi.

    Read the article

  • How to get associated URLRequest from Event.COMPLETE fired by URLLoader

    - by matt lohkamp
    So let's say we want to load some XML - var xmlURL:String = 'content.xml'; var xmlURLRequest:URLRequest = new URLRequest(xmlURL); var xmlURLLoader:URLLoader = new URLLoader(xmlURLRequest); xmlURLLoader.addEventListener(Event.COMPLETE, function(e:Event):void{ trace('loaded',xmlURL); trace(XML(e.target.data)); }); If we need to know the source URL for that particular XML doc, we've got that variable to tell us, right? Now let's imagine that the xmlURL variable isn't around to help us - maybe we want to load 3 XML docs, named in sequence, and we want to use throwaway variables inside of a for-loop: for(var i:uint = 3; i > 0; i--){ var xmlURLLoader:URLLoader = new URLLoader(new URLRequest('content'+i+'.xml')); xmlURLLoader.addEventListener(Event.COMPLETE, function(e:Event):void{ trace(e.target.src); // I wish this worked... trace(XML(e.target.data)); }); } Suddenly it's not so easy, right? I hate that you can't just say e.target.src or whatever - is there a good way to associate URLLoaders with the URL they loaded data from? Am I missing something? It feels unintuitive to me.

    Read the article

  • strategy for observer pattern?

    - by fayer
    I want to use observer pattern for a logging system. We have got logObservers and logObservables. The class that will have to log something will implement iLogObservable and include these methods: private $logObservers = array(); public function addLogObserver($logObserver) { $this->logObservers[] = $logObserver; } public function removeLogObserver($logObserver) { $this->logObservers[] = $logObserver; } public function write($type, $message) { foreach($this->logObservers as $logObserver) { $logObserver->log($level, $message); ; } } Then I noticed, that a lot of classes that will use logging will have these methods and I have to copy paste. So isn't it better to have these methods in a class I call LogObservable or just Log and then use strategy (instantiate this class inside all classes that will have to log). When I change the methods in Log, all logObservables will be affected. However, I have not seen anyone use observer pattern with strategy pattern yet, but it seems to be very efficient and remove the duplications. What do you think?

    Read the article

  • Workaround for abstract attributes in Java

    - by deamon
    In Scala I would write an abstract class with an abstract attribute path: abstract class Base { val path: String } class Sub extends Base { override val path = "/demo/" } Java doesn't know abstract attributes and I wonder what would be the best way to work around this limitation. My ideas: a) constructor parameter abstract class Base { protected String path; protected Base(String path) { this.path = path; } } class Sub extends Base { public Sub() { super("/demo/"); } } b) abstract method abstract class Base { // could be an interface too abstract String getPath(); } class Sub extends Base { public String getPath() { return "/demo/"; } } Which one do you like better? Other ideas? I tend to use the constructor since the path value should not be computed at runtime.

    Read the article

  • PHP 'instanceof' failing with class constant

    - by Nathan Loding
    I'm working on a framework that I'm trying to type as strongly as I possibly can. (I'm working within PHP and taking some of the ideas that I like from C# and trying to utilize them within this framework.) I'm creating a Collection class that is a collection of domain entities/objects. It's kinda modeled after the List<T> object in .Net. I've run into an obstacle that is preventing me from typing this class. If I have a UserCollection, it should only allow User objects into it. If I have a PostCollection, it should only allow Post objects. All Collections in this framework need to have certain basic functions, such as add, remove, iterate. I created an interface, but found that I couldn't do the following: interface ICollection { public function add($obj) } class PostCollection implements ICollection { public function add(Post $obj) {} } This broke it's compliance with the interface. But I can't have the interface strongly typed because then all Collections are of the same type. So I attempted the following: interface ICollection { public function add($obj) } abstract class Collection implements ICollection { const type = 'null'; } class PostCollection { const type = 'Post'; public function add($obj) { if(!($obj instanceof self::type)) { throw new UhOhException(); } } } When I attempt to run this code, I get syntax error, unexpected T_STRING, expecting T_VARIABLE or '$' on the instanceof statement. A little research into the issue and it looks like the root of the cause is that $obj instanceof self is valid to test against the class. It appears that PHP doesn't process the entire self::type constant statement in the expression. Adding parentheses around the self::type variable threw an error regarding an unexpected '('. An obvious workaround is to not make the type variable a constant. The expression $obj instanceof $this->type works just fine (if $type is declared as a variable, of course). I'm hoping that there's a way to avoid that, as I'd like to define the value as a constant to avoid any possible change in the variable later. Any thoughts on how I can achieve this, or have I take PHP to it's limit in this regard? Is there a way of "escaping" or encapsulating self::this so that PHP won't die when processing it?

    Read the article

  • In PHP, is it possible to create an instance of an class without calling class's constructor ?

    - by Rachel
    By any means, is it possible to create an instance of an php class without calling its constructor ? I have Class A and while creating an instance of it am passing file and in constructor of Class A am opening the file. Now in Class A, there is function which I need to call but am not required to pass file and so there is not need to use constructor functionality of opening file as am not passing file. So my question is, Is it possible by any means to create an instance of an PHP class without calling its constructor ?

    Read the article

  • Object-oriented GUI development in python

    - by ptabatt
    Hey guys, new programmer here. I have an assignment for class and I'm stuck... What I need to do is a create a GUI that gives someone a basic arithmetic problem in one box, asks the person to answer it, evaluates it, and tells you if you're right or wrong... Basically, what I have is this: [code] class Lesson(Frame): def init (self, parent=None): Frame.init(self, parent) self.pack() Lesson.make_widgets(self) def make_widgets(self): Label(self, text="").pack(side=TOP) ent = Entry(self) self.a = randrange(1,10) self.b = randrange(1,10) self.expr = choice(["+","-"]) ent.insert(END, str(self.a) + str(self.expr) + str(self.a)) [/code] I've broken this down into many little steps and basically, what I'm trying to do right now is insert a default random expression into the first entry widget. When I run this code, I just get a blank Label. Why is that? How can I put a something like "7+7" into the box? If you absolutely need background to the problem, it's question #3 on this link. http://reed.cs.depaul.edu/lperkovic/csc242/homeworks/Homework8.html -Thanks for all help in advance.

    Read the article

  • Placement of service methods

    - by mhp
    Let's assume I have two service classes with the following methods: GroupService createGroup() deleteGroup() updateGroup() findGroup() UserService createUser() deleteUser() updateUser() findUser() Now, I am thinking about the aesthetics of theses classes. Imagine we want to implement a method which search for all user of a specific group. Which service class is responsible for such a method? I mean, the return value is a user (or maybe a collection of users) but the parameter (which means the name of the group) is a group. So which service class is the better place to put this method in?

    Read the article

  • javascript constructor reset: What is it ?

    - by Sake
    I came across this slide: http://www.slideshare.net/stoyan/javascript-patterns#postComment at page 35: Option 5 + super + constructor reset function inherit(C, P) { var F = function(){}; F.prototype = P.prototype; C.prototype = new F(); C.uber = P.prototype; C.prototype.constructor = C; // WHY ??? } I don't get it. Can anybody please explain what the last line for ? C.prototype.constructor = C; // WHY ??? Thanks

    Read the article

< Previous Page | 19 20 21 22 23 24 25 26 27 28 29 30  | Next Page >