Search Results

Search found 3120 results on 125 pages for 'php5 oop'.

Page 39/125 | < Previous Page | 35 36 37 38 39 40 41 42 43 44 45 46  | Next Page >

  • Calling a subclass method from a superclass

    - by Shaun
    Preface: This is in the context of a Rails application. The question, however, is specific to Ruby. Let's say I have a Media object. class Media < ActiveRecord::Base end I've extended it in a few subclasses: class Image < Media def show # logic end end class Video < Media def show # logic end end From within the Media class, I want to call the implementation of show from the proper subclass. So, from Media, if self is a Video, then it would call Video's show method. If self is instead an Image, it would call Image's show method. Coming from a Java background, the first thing that popped into my head was 'create an abstract method in the superclass'. However, I've read in several places (including Stack Overflow) that abstract methods aren't the best way to deal with this in Ruby. With that in mind, I started researching typecasting and discovered that this is also a relic of Java thinking that I need to banish from my mind when dealing with Ruby. Defeated, I started coding something that looked like this: def superclass_method # logic this_media = self.type.constantize.find(self.id) this_media.show end I've been coding in Ruby/Rails for a while now, but since this was my first time trying out this behavior and existing resources didn't answer my question directly, I wanted to get feedback from more-seasoned developers on how to accomplish my task. So, how can I call a subclass's implementation of a method from the superclass in Rails? Is there a better way than what I ended up (almost) implementing?

    Read the article

  • Overload the equals method in java

    - by fastcodejava
    Does anyone overload the equals method in java? The overloaded method will be public boolean equals(final MyClass myClass) This will have the benefit of having the relevant comparison part (guts of the method) in another method. Details are in this blog.

    Read the article

  • What problems do you find with this view on domain-driven design?

    - by Bozho
    I just wrote a long (and messy) blogpost about my view on domain-driven design at present day, with frameworks like spring and hibernate massively in use. I'd ask you to spot any problems with my views on the matter - why this won't work, why it isn't giving the benefits of DDD, why it is not a good idea in general. The blogpost is here (I don't think I need to copy-paste it on SO - if you think I should, tell me). I know the question is subjective, but it is aimed at gathering the most predominant opinions. (I'm tagging Java, since the frameworks discussed are Java frameworks)

    Read the article

  • Most efficient way to update attribute of one instance

    - by Begbie00
    Hi all - I'm creating an arbitrary number of instances (using for loops and ranges). At some event in the future, I need to change an attribute for only one of the instances. What's the best way to do this? Right now, I'm doing the following: 1) Manage the instances in a list. 2) Iterate through the list to find a key value. 3) Once I find the right object within the list (i.e. key value = value I'm looking for), change whatever attribute I need to change. for Instance within ListofInstances: if Instance.KeyValue == SearchValue: Instance.AttributeToChange = 10 This feels really inefficient: I'm basically iterating over the entire list of instances, even through I only need to change an attribute in one of them. Should I be storing the Instance references in a structure more suitable for random access (e.g. dictionary with KeyValue as the dictionary key?) Is a dictionary any more efficient in this case? Should I be using something else? Thanks, Mike

    Read the article

  • Some specific questions about object oriented and MVC design.

    - by Samn
    I have two objects, Users and Mail. Users create Mail objects and send them to other users. If I wanted to get all mail for a User, I could create a method like GetMail() that would return an array of Mail objects owned by that User. But if I wanted to get all mail across the system, what "type" of object would be responsible for that? To solve this problem, I usually create a Manager, which is an object responsible for dealing with a collection of a particular type of object. MailManager deals with collections of Mail objects. GetMailForUser() is one method, GetAllMail() is another method. The User objects invokes the MailManager and executes GetMailForUser(me). Is this stupid? When a user executes the controller CreateMail, a new instance of the Mail object is created. The Mail object, seeing it is creating a new Mail of type 'sent', decides to go ahead and create a second Mail object for the recipient, of type 'received'. Creating one Mail object triggers the creation of a second Mail object. Is this stupid? Should the controller have created both Mail objects, or just the first 'sent' one? When two Users are friends, the association is stored in a table of Relationships. I use a simple object for Relationships. A RelationshipManager has a method called GetFriendsForUser(). The User object has a method GetFriends(), which invokes the RelationshipManager. Is this stupid?

    Read the article

  • when does static member gets memory.

    - by vaibhav
    I have a class which have a static member. As I understand all static members are common for all instance of the class. So it means static members would get memory only once. Where is this memory is allocated (Stack or Heap) and when this memory get allocated.

    Read the article

  • When exactly does a method have side effects?

    - by Kim
    As I always understood it, any change to the programs state (or anything to do with IO) is a side effect. It does not matter, whether the change occurs in a global variable or in a private field of the object the method is called on. It follows that all methods which do not return anything either do nothing at all or have a side effect. My confusion comes from one of our university's instructors (who is still a student and thus not omniscient yet;) ) telling me setters don't have side effects.

    Read the article

  • List<> of objects, different types, sort and pull out types individually?

    - by Brazos
    I've got a handful of products, any, all, or none of which may be associated with a specific submission. All 7 products are subclasses of the class Product. I need to store all the products associated with a submission, and then retrieve them and their field data on my presentation layer. I've been using a List, and List, but when I use the OfType, I throw an error saying that I can't implicitly convert systems.generic.IEnumerable to type 'Product'. I've tried to cast, but to no avail. When I use prodlist.OfType<EPL>(); there are no errors, but when I try and store that in an instance of EPL "tempEpl", I get the aforementioned cast-related error. What gives? Code below. ProductService pserv = new ProductService(); IList<object> prodlist = pserv.getProductById(x); EPL tempEpl = new EPL(); if ((prodlist.OfType<EPL>()) != null) { tempEpl = prodlist.OfType<EPL>(); // this throws a conversion error. } the Data layer List<object> TempProdList = new List<object>(); conn.Open(); SqlCommand EplCmd = new SqlCommand(EPLQuery, conn); SqlDataReader EplRead = null; EplRead = EplCmd.ExecuteReader(); EPL TempEpl = new EPL(); if (EplRead.Read()) { TempEpl.Entity1 = EplRead.GetString(0); TempEpl.Employees1 = EplRead.GetInt32(1); TempEpl.CA1 = EplRead.GetInt32(2); TempEpl.MI1 = EplRead.GetInt32(3); TempEpl.NY1 = EplRead.GetInt32(4); TempEpl.NJ1 = EplRead.GetInt32(5); TempEpl.PrimEx1 = EplRead.GetInt32(6); TempEpl.EplLim1 = EplRead.GetInt32(7); TempEpl.EplSir1 = EplRead.GetInt32(8); TempEpl.Premium1 = EplRead.GetInt32(9); TempEpl.Wage1 = EplRead.GetInt32(10); TempEpl.Sublim1 = EplRead.GetInt32(11); TempProdList.Add(TempEpl); }

    Read the article

  • Resetting Objects vs. Constructing New Objects

    - by byronh
    Is it considered better practice and/or more efficient to create a 'reset' function for a particular object that clears/defaults all the necessary member variables to allow for further operations, or to simply construct a new object from outside? I've seen both methods employed a lot, but I can't decide which one is better. Of course, for classes that represent database connections, you'd have to use a reset method rather than constructing a new one resulting in needless connecting/disconnecting, but I'm talking more in terms of abstraction classes. Can anyone give me some real-world examples of when to use each method? In my particular case I'm thinking mostly in terms of ORM or the Model in MVC. For example, if I would want to retrieve a bunch of database objects for display and modify them in one operation.

    Read the article

  • PHP Classes: Call method in instance of a class by instance's name

    - by Ursus Russus
    Hi, i have a class of this kind Class Car { private $color; public function __construct($color){ $this->color=$color; } public function get_color(){ return $this->$color; } } Then i create some instances of it: $blue_car = new car('blue'); $green_car = new car('green'); etc. Now i need to call method get_color() on the fly, according to instance's name $instance_name='green_car'; Is there any way to do it?

    Read the article

  • How do I know which Object I clicked?

    - by Nick
    Here's the deal: I'm working on a personal portfolio in AS3 and I've run into a problem which I can't seem to find a logical answer to. I want everything (well, most of it) to be editable with an XML file, including my menu. My menu is just a Sprite with some text on it and a Tweener-tween, no big deal. But, I forgot to think of a way how I can determine which menu-item I have clicked. This is in my Main.as private function xmlLoaded(e:Event):void { xml = e.target.xml; menu = new Menu(xml); menu.x = 0; menu.y = stage.stageHeight / 2 - menu.height / 2; addChild(menu); } In Menu.as public function Menu(xml:XML) { for each (var eachMenuItem:XML in xml.menu.item) { menuItem = new MenuItem(eachMenuItem); menuItem.y += yPos; addChild(menuItem); yPos += menuItem.height + 3; } } and in my MenuItem.as, everything works - I have a fancy tween when I hover over it, but when I click a menu-item, I want something to appear ofcourse. How do I know which one I clicked? I've tried with pushing everything in an array, but that didn't work out well (or maybe I'm doing it wrong). Also tried a global counter, but that's not working either because the value will always be amount of items in my XML file. Also tried e.currentTarget in my click-function, but when I trace that, all of them are "Object Sprite".. I need something so I can give each a unique "name"? Thanks in advance!

    Read the article

  • How can i return dataset perfectly from sql?

    - by Phsika
    i try to write a winform application: i dislike below codes: DataTable dt = new DataTable(); dt.Load(dr); ds = new DataSet(); ds.Tables.Add(dt); Above part of codes looks unsufficient.How can i best loading dataset? public class LoadDataset { public DataSet GetAllData(string sp) { return LoadSQL(sp); } private DataSet LoadSQL(string sp) { SqlConnection con = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"].ToString()); SqlCommand cmd = new SqlCommand(sp, con); DataSet ds; try { con.Open(); cmd.CommandType = CommandType.StoredProcedure; SqlDataReader dr = cmd.ExecuteReader(); DataTable dt = new DataTable(); dt.Load(dr); ds = new DataSet(); ds.Tables.Add(dt); return ds; } finally { con.Dispose(); cmd.Dispose(); } } }

    Read the article

  • Limiting method access in protected section to few classes

    - by Bharat
    Hi, I want to limit the access of protected methods to certain inherited classes only. For example there is a base class like TBase = Class Protected Method1; Method2; Method3; Method4; End; I have two classes derived from TBase TDerived1 = Class(TBase) //Here i must access only Method1 and Method2 End; TDerived2 = Class(TBase) //Here i must access only Method3 and Method4 End; Then is it possible to access only Method1 and Method2 when i use objects of TDerived1 and Method3 and Method4 when i use objects of TDerived2

    Read the article

  • What's wrong with my destructor?

    - by Ahmed Sharara
    // Sparse Array Assignment.cpp : Defines the entry point for the console application. // #include "stdafx.h" #include<iostream> using namespace std; struct node{ int row; int col; int value; node* next_in_row; node* next_in_col; }; class MultiLinkedListSparseArray { private: char *logfile; node** rowPtr; node** colPtr; // used in constructor node* find_node(node* out); node* ins_node(node* ins,int col); node* in_node(node* ins,node* z); node* get(node* in,int row,int col); bool exist(node* so,int row,int col); node* dummy; int rowd,cold; //add anything you need public: MultiLinkedListSparseArray(int rows, int cols); ~MultiLinkedListSparseArray(); void setCell(int row, int col, int value); int getCell(int row, int col); void display(); void log(char *s); void dump(); }; MultiLinkedListSparseArray::MultiLinkedListSparseArray(int rows,int cols){ rowPtr=new node* [rows+1]; colPtr=new node* [cols+1]; for(int n=0;n<=rows;n++) rowPtr[n]=NULL; for(int i=0;i<=cols;i++) colPtr[i]=NULL; rowd=rows;cold=cols; } MultiLinkedListSparseArray::~MultiLinkedListSparseArray(){ cout<<"array is deleted"<<endl; for(int i=rowd;i>=0;i--){ for(int j=cold;j>=0;j--){ if(exist(rowPtr[i],i,j)) delete get(rowPtr[i],i,j); } } // it stops in the last loop & doesnt show the done word cout<<"done"<<endl; delete [] rowPtr; delete [] colPtr; delete dummy; } void MultiLinkedListSparseArray::log(char *s){ logfile=s; } void MultiLinkedListSparseArray::setCell(int row,int col,int value){ if(exist(rowPtr[row],row,col)){ (*get(rowPtr[row],row,col)).value=value; } else{ if(rowPtr[row]==NULL){ rowPtr[row]=new node; (*rowPtr[row]).value=value; (*rowPtr[row]).row=row; (*rowPtr[row]).col=col; (*rowPtr[row]).next_in_row=NULL; (*rowPtr[row]).next_in_col=NULL; } else if((*find_node(rowPtr[row])).col<col){ node* out; out=find_node(rowPtr[row]); (*out).next_in_row=new node; (*((*out).next_in_row)).col=col; (*((*out).next_in_row)).row=row; (*((*out).next_in_row)).value=value; (*((*out).next_in_row)).next_in_row=NULL; } else if((*find_node(rowPtr[row])).col>col){ node* ins; ins=in_node(rowPtr[row],ins_node(rowPtr[row],col)); node* g=(*ins).next_in_row; (*ins).next_in_row=new node; (*((*ins).next_in_row)).col=col; (*(*ins).next_in_row).row=row; (*(*ins).next_in_row).value=value; (*(*ins).next_in_row).next_in_row=g; } } } int MultiLinkedListSparseArray::getCell(int row,int col){ return (*get(rowPtr[row],row,col)).value; } void MultiLinkedListSparseArray::display(){ for(int i=1;i<=5;i++){ for(int j=1;j<=5;j++){ if(exist(rowPtr[i],i,j)) cout<<(*get(rowPtr[i],i,j)).value<<" "; else cout<<"0"<<" "; } cout<<endl; } } node* MultiLinkedListSparseArray::find_node(node* out) { while((*out).next_in_row!=NULL) out=(*out).next_in_row; return out; } node* MultiLinkedListSparseArray::ins_node(node* ins,int col){ while(!((*ins).col>col)) ins=(*ins).next_in_row; return ins; } node* MultiLinkedListSparseArray::in_node(node* ins,node* z){ while((*ins).next_in_row!=z) ins=(*ins).next_in_col; return ins; } node* MultiLinkedListSparseArray::get(node* in,int row,int col){ dummy=new node; dummy->value=0; while((*in).col!=col){ if((*in).next_in_row==NULL){ return dummy; } in=(*in).next_in_row; } return in; } bool MultiLinkedListSparseArray::exist(node* so,int row,int col){ if(so==NULL) return false; else{ while((*so).col!=col){ if((*so).next_in_row==NULL) return false; else so=(*so).next_in_row; } return true; } }

    Read the article

  • HMVC or PAC - how to handle shared abstractions/models?

    - by fig-gnuton
    In HMVC/PAC, what's the recommended way to code if two or more triads/agents share a common model/abstraction? Do you instantiate a new instance of that model wherever needed, and propogate a change in one to all the other instances via the controllers? Or do instantiate one model at some common upper level, and inject that instance wherever needed? (Or neither if I'm missing something fundamental about these patterns?)

    Read the article

  • Example of forum in Object Oriented PHP

    - by Martin Trigaux
    Hello, I'm trying to learn to use PHP with an object oriented scheme. I think I understand the concept but I need real example, a forum exactly (the closest to what I want to do). I know PhpBB but it's maybe too complicated to fully understand it so I'm looking for something simpler but still in object oriented. Do you know any ? Thank you

    Read the article

  • how to return the current object?

    - by ajsie
    in code igniter you can type: $query = $this->db->query("YOUR QUERY"); foreach ($query->result() as $row) { echo $row->title; echo $row->name; echo $row->body; } i guess that the query method returns the object it's part of. am i correct? if i am, how do you type the line where it returns the object? so what i wonder is how it looks like inside the query method for the above code to be functional. public function query($sql) { // some db logic here with the $sql and saves the values to the properties (title, name and body) return X } with other words, what should X be?

    Read the article

  • real time scenario between interface/abstract class ?

    - by JavaUser
    Hi , Please give me a real time simple example for the below questions : Where to use interface rather abstract class Where to use abstract class rather interface I need code snippet for both . Which takes low memory and which performs well . Do I need to consider the design aspect also? What is the conceptual difference not the syntactical difference .

    Read the article

  • An inaccessible class. VS2010.

    - by Mishgun_
    I realy dont know what the problem is with VS2010. I created a class, and when I'm trying create an exemplar of the class I get an error: "Error xxx is inaccessible due to its protection level. Example: public class Person { Person(string name, int age) { this.name = name; this.age = age; } public string name; public int age; } class Program { static void Main(string[] args) { Person ps = new Person("Jack", 19); } }

    Read the article

  • Does Javascript have classes?

    - by Glycerine
    A friend and I had an argument last week. He stated there were no such things as classes in Javascript. I said there was as you can say var object = new Object() he says "as there is no word class used. Its not a class. -- Whats your take on it guys? thanks.

    Read the article

  • C++ overloading virtual = operator

    - by taz
    Hello, here is the code for my question: class ICommon { public: virtual ICommon& operator=(const ICommon & p)const=0; }; class CSpecial : public ICommon { public: CSpecial& operator=(const CSpecial & cs) { //custom operations return *this; } }; CSpecial obj; Basically: I want the interface ICommon to force it's descendants to implement = operator but don't want to have any typecasts in the implementation. The compiler says "can't instantiate an abstract class. Any help/advice will be appreciated.

    Read the article

< Previous Page | 35 36 37 38 39 40 41 42 43 44 45 46  | Next Page >