Search Results

Search found 31582 results on 1264 pages for 'software design'.

Page 404/1264 | < Previous Page | 400 401 402 403 404 405 406 407 408 409 410 411  | Next Page >

  • What is the definition of a Service object ?

    - by Maskime
    I've been working a lot with PHP. But recently i was sent on a work wich use Java. In PHP i used to do a lot of Singleton object but this pattern has not the same signification in Java that it has in PHP. So i wanted to go for an utility class (a class with static method) but my chief doesn't like this kind of classes and ask me to go for services object. So my guess was that a service object is just a class with a constructor that implement some public methods... Am i right ?

    Read the article

  • Should I use multiple threads in this situation? [Ruby]

    - by mr popo
    I'm opening multiple files and processing them, one line at a time. The files contain tokens separating the data, such that sometimes the processing of one file may have to wait for others to catch up to that same token. I was doing this initially with only one thread and an array indicating with true/false if the file should be read in the current iteration or if it should wait for some of the others to catch up. Would using threads make this simpler? More efficient? Does Ruby have a mechanism for this?

    Read the article

  • correct technical term for this pattern

    - by Oliver A.
    sometimes I use a pattern which is very similar to the singleton pattern: There is one default instance which and a static get method to aces it. But you may create other instances and pass it as optional parameter and if you want to and you can even replace the default instance with a instance from a child class. So it is NO SINGLETON at all but it is used like one singleton in most cases. Anyone got an idea who to call something like this ? Maybe half*** singleton? domiton?

    Read the article

  • Best way to store this data?

    - by Malfist
    I have just been assigned to renovate an old website, and I get to move it from some old archaic system to drupal. The only problem is that it's a real-estate system and a lot of data is stored. Currently all the information is stored in a single table, an id represents the house and then everything else is key/value pairs. There are a possible 243 keys per estate, there are 23840 estates in the system. As you can imagine the system is slow and difficult to query. I don't think a table with 243 rows would be a very good idea, and probably worse than the current situation. I've done some investigating and here's what I've found out: Missing data does not indicate a 0 value, data is merged from two, unique sources/formats. Some guessing is involved. I have no control over the source of the data. There are 4 keys that are common to all estates, all values look like something that is commonly searched for and could be indexed There are 10 keys that are in the [90-100)% range 8 of these are information like who's selling it, and it's address. The other two seem to belong with the below range There are 80 keys that are in the [80-90)% range This range seems to mostly just list room types and how many the house has (e.g. bedrooms_possible, bathrooms, family_room_3rd, etc) This range also includes some minor information like school districts, one or two more pieces of data on the address. The 179 keys that are in the [0-80)% range include all sorts of miscellaneous information about the estate My best idea was a hybrid approach, create a table that stores important, common information and keep a smaller key/value table. How would you store this information?

    Read the article

  • Static and default constuctor

    - by Ram
    A non static class can have static as well as default constructor at the same time. What is the difference between these two constructors? When shall I go for only static or static with default constructor?

    Read the article

  • Setting the type of a field in a superclass from a subclass (Java)

    - by Ibolit
    Hi. I am writing a project on Google App Engine, within it I have a number of abstract classes that I hope I will be able to use in my future projects, and a number of concrete classes inheriting from them. Among other abstract classes I have an abstract servlet that does user management, and I hava an abstract user. The AbstractUser has all the necessary fields and methods for storing it in the datastore and telling whether the user is registered with my service or not. It does not implement any project specific functionality. The abstract servlet that manages users, refers only to the methods declared in the AbstractUser class, which allows it to generate links for logging in, logging out and registering (for unregistered users). In order to implement the project-specific user functionality I need to subclass the Abstract user. The servlets I use in my project are all indirect descendants from that abstract user management servlet, and the user is a protected field in it, so the descendant servlets can use it as their own field. However, whenever i want to access any project specific method of the concrete user, i need to cast it to that type. i.e. (abstract user managing servlet) ... AbstractUser user = getUser(); ... abstract protected AbstractUser getUser(); (project-specific abstract servlet) @Override protected AbstractUser getUser() { return MyUserFactory.getUser(); } any other project specific servlet: int a = ((ConcreteUser) user).getA(); Well, what i'd like to do is to somehow make the type of “user” in the superclass depend on something in the project-specific abstract class. Is it at all possible? And i don't want to move all the user-management stuff into a project-specific layer, for i would like to have it for my future projects already written :) Thank you for your help.

    Read the article

  • Sharing class member data between sub components

    - by Tim Gradwell
    I have an aggregate 'main' class which contains some data which I wish to share. The main class also has other class members. I want to share the data with these other class members. What is the correct / neatest way to do this? The specific example I have is as follows. The main class is a .net Form. I have some controls (actually controls within controls) on the main form which need access to the shared data. Main Form - DataX - DataY - Control1 -- Subcontrol1 - Control2 -- SubControl2 SubControls 1 and 2 both wish to access DataX and DataY. The trouble is, I feel like better practice (to reduce coupling), would be that either subcontrols should not know about Main Form, or Main Form should not know about subcontrols - probably the former. For subcontrols not to know about Main Form, would probably mean Main Form passing references to both Controls 1 and 2, which in turn would pass the references on to SubControls 1 and 2. Lots of lines of code which just forward the references. If I later added DataZ and DataW, and Controls 3 and 4 and SubControls 3 and 4, I'd have to add lots more reference forwarding code. It seems simpler to me to give SubControls 1 and 2 member references to Main Form. That way, any sub control could just ask for MainForm.DataX or MainForm.DataY and if I ever added new data, I could just access it directly from the sub controls with no hassle. But it still involves setting the 'MainForm' member references every time I add a new Control or Subcontrol. And it gives me a gut feeling of 'wrong'. As you might be able to tell I'm not happy with either of my solutions. Is there a better way? Thanks

    Read the article

  • How to store opening weekdays in a database

    - by JoaoPedro
    I have a group of checkboxes where the user selects some of the weekdays (the opening days of a store). How can I save the selected days? Should I save something like 0111111 (zero means closed on sunday) on the same field and split the result when reading the data? Or create a field for each day and store 0 or 1 on each (weird)?

    Read the article

  • What pattern is this? php

    - by user151841
    I have several classes that are basically interfaces to database rows. Since the class assumes that a row already exists ( __construct expects a field value ), there is a public static function that allows creation of the row and returns an instance of the class. Here's an example ( without the actual database inserts ): class selfStarter { public $type; public function __construct( $type ) { $this->type = $type; } public static function create( $type ) { if ( ! empty($type) ) { $starter = & new selfStarter($type); return $starter; } } } $obj1 = selfStarter::create( "apple" ); $obj2 = & new selfStarter( "banana" ); What is this pattern called?

    Read the article

  • guarantee child records either in one table or another, but not both?

    - by user151841
    I have a table with two child tables. For each record in the parent table, I want one and only one record in one of the child tables -- not one in each, not none. How to I define that? Here's the backstory. Feel free to criticize this implementation, but please answer the question above, because this isn't the only time I've encountered it: I have a database that holds data pertaining to user surveys. It was originally designed with one authentication method for starting a survey. Since then, requirements have changed, and now there are two different ways someone could sign on to start a survey. Originally I captured the authentication token in a column in the survey table. Since requirements changed, there are three other bits of data that I want to capture in authentication. So for each record in the survey table, I'm either going to have one token, or a set of three. All four of these are of different types, so my thought was, instead of having four columns where either one is going to be null, or three are going to be null ( or even worse, a bad mashup of either of those scenarios ), I would have two child tables, one for holding the single authentication token, the other for holding the three. Problem is, I don't know offhand how to define that in DDL. I'm using MySQL, so maybe there's a feature that MySQL doesn't implement that lets me do this.

    Read the article

  • Class with proprties that haven't been set

    - by koumides
    Hello there, I am creating a class in C# which eventually will be part of a library that other uses can use. A user of this class has to set some properties and then use a public method to retrieve the results. What shall I do when a user calls the method without setting all the properties? Throw exception and expect the user to catch it? Thanks

    Read the article

  • Constructors + Dependency Injection

    - by Sunny
    If I am writing up a class with more than 1 constructor parameter like: class A{ public A(Dependency1 d1, Dependency2 d2, ...){} } I usually create a "argument holder"-type of class like: class AArgs{ public Dependency1 d1 { get; private set; } public Dependency2 d2 { get; private set; } ... } and then: class A{ public A(AArgs args){} } Typically, using a DI-container I can configure the constructor for dependencies & resolve them & so there is minimum impact when the constructors need to change. Is this considered an anti-pattern and/or any arguments against doing this?

    Read the article

  • C++: Conceptual problem in designing an intepreter

    - by sub
    I'm programming an interpreter for an experimental programming language (educational, fun,...) So far, everything went well (Tokenizer & Parser), but I'm getting a huge problem with some of the data structures in the part that actually runs the tokenized and parsed code. My programming language basically has only two types, int and string, and they are represented as C++ strings (std class) and ints Here is a short version of the data structure that I use to pass values around: enum DataType { Null, Int, String } class Symbol { public: string identifier; DataType type; string stringValue; int intValue; } I can't use union because string doesn't allow me to. This structure above is beginning to give me a headache. I have to scatter code like this everywhere in order to make it work, it is beginning to grow unmaintainable: if( mySymbol.type == Int ) { mySymbol.intValue = 1234; } else { mySymbol.stringValue = "abcde"; } I use the Symbol data structure for variables, return values for functions and general representation of values in the programming language. Is there any better way to solve this? I hope so!

    Read the article

  • In what package should a "Settings" class be placed?

    - by Tom
    I'm in the middle of building an application but found myself too easily creating new packages without keeping the project's structure in mind. Now, I'm trying to redo the whole project structure on paper first. I am using a Settings class with public properties, accessed as settings for several other classes around the project. Now, since this Settings class applies for the whole project, I am unsure if it should be packaged and if so, in what kind of package should it exist? Or should it be in the root (the default package) with the main application class? I've been thinking about putting it in my utils package, then again I don't think it really is an utlity. Any strategies on how to decide on such package structure for example for a Settings class?

    Read the article

  • Interpreted languages: The higher-level the faster?

    - by immersion
    I have designed around 5 experimental languages and interpreters for them so far, for education, as a hobby and for fun. One thing I noticed: The assembly-like language featuring only subroutines and conditional jumps as structures was much slower than the high-level language featuring if, while and so on. I developed them both simultaneously and both were interpreted languages. I wrote the interpreters in C++ and I tried to optimize the code-execution part to be as fast as possible. My hypothesis: In almost all cases, performance of interpreted languages rises with their level (high/low). Am I basically right with this? (If not, why?)

    Read the article

  • STLifying C++ classes

    - by shambulator
    I'm trying to write a class which contains several std::vectors as data members, and provides a subset of vector's interface to access them: class Mesh { public: private: std::vector<Vector3> positions; std::vector<Vector3> normals; // Several other members along the same lines }; The main thing you can do with a mesh is add positions, normals and other stuff to it. In order to allow an STL-like way of accessing a Mesh (add from arrays, other containers, etc.), I'm toying with the idea of adding methods like this: public: template<class InIter> void AddNormals(InIter first, InIter last); Problem is, from what I understand of templates, these methods will have to be defined in the header file (seems to make sense; without a concrete iterator type, the compiler doesn't know how to generate object code for the obvious implementation of this method). Is this actually a problem? My gut reaction is not to go around sticking huge chunks of code in header files, but my C++ is a little rusty with not much STL experience outside toy examples, and I'm not sure what "acceptable" C++ coding practice is on this. Is there a better way to expose this functionality while retaining an STL-like generic programming flavour? One way would be something like this: (end list) class RestrictedVector<T> { public: RestrictedVector(std::vector<T> wrapped) : wrapped(wrapped) {} template <class InIter> void Add(InIter first, InIter last) { std::copy(first, last, std::back_insert_iterator(wrapped)); } private: std::vector<T> wrapped; }; and then expose instances of these on Mesh instead, but that's starting to reek a little of overengineering :P Any advice is greatly appreciated!

    Read the article

  • One database or many?

    - by dsims
    I am developing a website that will manage data for multiple entities. No data is shared between entities, but they may be owned by the same customer. A customer may want to manage all their entities from a single "dashboard". So should I have one database for everything, or keep the data seperated into individual databases? Is there a best-practice? What are the positives/negatives for having a: database for the entire site (entity has a "customerID", data has "entityID") database for each customer (data has "entityID") database for each entity (relation of database to customer is outside of database) Multiple databases seems like it would have better performance (fewer rows and joins) but may eventually become a maintenance nightmare.

    Read the article

  • is Payment table needed when you have an invoice table like this?

    - by EBAGHAKI
    this is my invoice table: Invoice Table: invoice_id creation_date due_date payment_date status enum('not paid','paid','expired') user_id total_price I wonder if it's Useful to have a payment table in order to record user payments for invoices. payment table can be like this: payment_id payment_date invoice_id price_paid status enum('successful', 'not successful')

    Read the article

  • How to set a value from another class

    - by Ram
    Its said that property should not be "Set" only and it should be "Get" as well. What should i do if I need to set value to a variable from some other class? The will keep changing so I cannot pass it through constructor. Shall I create a function for this as shown below? class A { public void SetValue() { b = new B(); b.SetTest(10); } } class B { int test; public void SetTest(int value) { test = value; } } What are the other alternatives?

    Read the article

< Previous Page | 400 401 402 403 404 405 406 407 408 409 410 411  | Next Page >