Search Results

Search found 14279 results on 572 pages for 'design choices'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 230/572 | < Previous Page | 226 227 228 229 230 231 232 233 234 235 236 237  | Next Page >

  • Designing a chain of states

    - by devoured elysium
    I want to model a kind of FSM(Finite State Machine). I have a sequence of states (let's say, from StateA to StateZ). This sequence is called a Chain and is implemented internally as a List. I will add states by the order I want them to run. My purpose is to be able to make a sequence of actions in my computer (for example, mouse clicks). (I know this has been done a zillion times). So a state is defined as a: boolean Precondition() <- Checks to see if for this state, some condition is true. For example, if I want to click in the Record button of a program, in this method I would check if the program's process is running or not. If it is, go to the next state in the chain list, otherwise, go to what was defined as the fail state (generally is the first state of them all). IState GetNextState() <- Returns the next state to evaluate. If Precondition() was sucessful, it should yield the next state in the chain otherwise it should yield the fail state. Run() Simply checks the Precondition() and sets the internal data so GetNextState() works as expected. So, a naive approach to this would be something like this: Chain chain = new Chain(); //chain.AddState(new State(Precondition, FailState, NextState) <- Method structure chain.AddState(new State(new WinampIsOpenCondition(), null, new <problem here, I want to referr to a state that still wasn't defined!>); The big problem is that I want to make a reference to a State that at this point still wasn't defined. I could circumvent the problem by using strings when refrering to states and using an internal hashtable, but isn't there a clearer alternative? I could just pass only the pre-condition and failure states in the constructor, having the chain just before execution put in each state the correct next state in a public property but that seems kind of awkward.

    Read the article

  • Best practice for passing configuration to each GUI object

    - by Laimoncijus
    Hi, I am writing an application, where I do have few different windows implemented, where each window is a separate class. Now I need somehow to pass a single configuration object to all of them. My GUI is designed in way, where I have one main window, which may create some child windows of its own, and these child windows can have their own childs (so there is no possibility to create all windows in initialization part and feed the config object to all of them from the very beginning)... What would be best practice for sharing this configuration object between them? Always passing via constructor or maybe making it somewhere as final public static and let each window object to access it when needed? Thanks

    Read the article

  • Re-usable Obj-C classes with custom values: The right way

    - by Prairiedogg
    I'm trying to reuse a group of Obj-C clases between iPhone applications. The values that differ from app to app have been isolated and I'm trying to figure out the best way to apply these custom values to the classes on an app-to-app basis. Should I hold them in code? // I might have 10 customizable values for each class, that's a long signature! CarController *controller = [[CarController alloc] initWithFontName:@"Vroom" engine:@"Diesel" color:@"Red" number:11]; Should I store them in a big settings.plist? // Wasteful! I sometimes only use 2-3 of 50 settings! AllMyAppSettings *settings = [[AllMyAppSettings alloc] initFromDisk:@"settings.plist"]; MyCustomController *controller = [[MyCustomController alloc] initWithSettings:settings]; [settings release]; Should I have little, optional n_settings.plists for each class? // Sometimes I customize CarControllerSettings *carSettings = [[CarControllerSettings alloc] initFromDisk:@"car_settings.plist"]; CarController *controller = [[CarController alloc] initWithSettings:carSettings]; [carSettings release]; // Sometimes I don't, and CarController falls back to internally stored, reasonable defaults. CarController *controller = [[CarController alloc] initWithSettings:nil]; Or is there an OO solution that I'm not thinking of at all that would be better?

    Read the article

  • Bad idea to have the same object, have a different side effect after method call.

    - by Nathan W
    Hi all, I'm having a bit of a gesign issue(again). Say I have this Buttonpad object: now this object is a wrapper object over one in a com object. At the moment it has a method on it called CreateInto(IComObject). Now to make a new button pad in the Com Object. You do: ButtonPad pad = new ButtonPad(); pad.Title = "Hello"; // Set some more properties. pad.CreateInto(Cominstance); The createinfo method will excute the right commands to buid the button pad in the com object. After it has been created it any calls against it are foward to the underlying object for change so: pad.Title = "New title"; will call the com object to set the title and also set the internal title variable. Basically any calls before the CreateInfo method only affect the .NET object anything after has the side effect of calling the com object also. I'm not very good at sequence diagrams but here is my attempt to explain whats going on: This doesn't feel good to me, it feels like I'm lying to the user about what the button pad does. I was going to have a object called WrappedButtonPad, which is returned from CreateInto and the user could make calls against that to make changes to the Com Object, but I feel having two objects that almost do the same thing but only differ by names might be even worse. Are these valid designs, or am I right to be worried? How else would you handle a object the can create and query a com object?

    Read the article

  • What is the standard way to add an icon to a link with CSS?

    - by ewernli
    I'm used to use padding + background-image to place an icon next to a link. There are many example of this approach. Here is one from here: <a class="external" href="http://www.othersite.com/">link</a> a.external { padding-right: 15px; background: transparent url(images/external-link-icon.gif) no-repeat top right; } But most browser don't print background image, which is annoying. What is the standard to place icon next to links which is semantically correct and works in all cases? (I couldn't find an exact similar question. If there is one, just close this one as duplicate)

    Read the article

  • 'Static/Constant' business ojects

    - by UpTheCreek
    I don't quite know how to ask this question, so I'll phase it as an example: Imagine in an application you have a Country object. There are two properties of this object: Name, and a 'Bordering Countries' collection. More properties might be added later, but it will be the kind of information that would change very rarely (e.g. changes of country names/borders) Lets say this application needs to know about all of the countries in the world. Where would you store these object's state? How would you new them up? It seems silly to store all this state in the DB, since it won't change very often. One option might be to have an abstract 'country' base object, and have a class for each country inheriting from this with the details of each country. But this doesn't seem quite right to me. What is the proper way of dealing with these kinds of objects?

    Read the article

  • How many databases to support eCommerce?

    - by Terry Lorber
    I have a system with two databases, one that the customer-facing website uses, the second that is used by the "backroom" order-fulfillment system. I've been asked to run queries from the website to the backroom system. I'd rather not, it seems risky to allow web-based request to run unheeded on the internal system. Additionally, this means opening up routing in the firewall to allow external connections to the internal server. What's the best practice for eCommerce? Run the entire company off of one database? Or individual databases for each system, and middleware to connect them? Sometimes it might be necessary for the web application to pull date from the internal system, but not based on an HTTP request from the internet. I'm sure the best answer is "it depends!" So, if people have a rule of thumb for when to use middleware and when not to, I'd like to here it.

    Read the article

  • Find a regular expression that matches a string?

    - by Mirai
    I need a model for finding all of the regular expressions that would match a particular string. Basically, I need an algorithm for doing what I do to generate a regex search string from some pattern. My purpose for this to create a list of potential regular expressions from a selection of text and order that list from least specific (i.e. string of characters with abitrary length) to most specific (i.e. the string itself) to be used in text editor.

    Read the article

  • Determining Best Table Structure for MySQL Performance

    - by Joe Majewski
    I'm working on a browser-based RPG for one of my websites, and right now I'm trying to determine the best way to organize my SQL tables for performance and maintenance. Here's my question: Does the number of columns in an SQL table affect the speed in which it can be queried? I am not a newbie when it comes to PHP or MySQL. I used to develop things with the common goal of getting them to work, but I've recently advanced to the stage where a functional program is not good enough unless it's fast and reliable. Anyways, right now I have a members table that has around 15 columns. It contains information such as the player's username, password, email, logins, page views, etcetera. It doesn't contain any information on the player's progress in the game, however. If I added columns for things such as army size, gold, turns, and whatnot, then it could easily rise to around 40 or 50 total columns. Oh, and my database structure IS normalized. Will a table with 50 columns that gets constantly queried be a bad idea? Should I split it into two tables; one for the user's general information and one for the user's game statistics? I know I could check the query time myself, but I haven't actually created the tables yet and I think I'd be better off with some professional advice on this important decision for my game. Thank you for your time! :)

    Read the article

  • Connecting data to a GUI - OOP

    - by tau
    I have an application with several graphs and tables on it. I worked fast and just made classes like Graph and Table that each contained a request object (pseudo-code): class Graph { private request; public function setDateRange(dateRange) { request.setDateRange(dateRange); } public function refresh() { request.getData(function() { //refresh the display }); } } Upon a GUI event (say, someone changes the date range dropdown), I'd just call the setters on the Graph instance and then refresh it. Well, when I added other GUI elements like tables and whatnot, they all basically had similar methods (setDateRange and other things common to the request). What are some more elegant OOP ways of doing this? The application is very simple and I don't want to over-architect it, but I also don't want to have a bunch of classes with basically the same methods that are just routing to a request object. I also don't want to set up each GUI class as inheriting from the request class, but I'm open to any ideas really.

    Read the article

  • Does OOP make sense for small scripts?

    - by Fabian
    I mostly write small scripts in python, about 50 - 250 lines of code. I usually don't use any objects, just straightforward procedural programming. I know OOP basics and I have used object in other programming languages before, but for small scripts I don't see how objects would improve them. But maybe that is just my limited experience with OOP. Am I missing something by not trying harder to use objects, or does OOP just not make a lot of sense for small scripts?

    Read the article

  • Why doesn't Java Map extends Collection?

    - by polygenelubricants
    I was surprised by the fact that Map<?,?> is not a Collection<?>. I thought it'd make a LOT of sense if it was declared as such: public interface Map<K,V> extends Collection<Map.Entry<K,V>> After all, a Map<K,V> is a collection of Map.Entry<K,V>, isn't it? So is there a good reason why it's not implemented as such?

    Read the article

  • Searching for the right pattern to handle login data

    - by stevebot
    Hi all, I'm working on a controller that handles logins for a Web app. These logins will come from multiple clients but will all contain the same data. However, depending on the client, this data will be interpreted into common entities for our webapp differently. For instance, we have a user code that gets sent in, and in one case we may use the first four digits of the code, and in another case 12 digits of the code to map to a field on a User entity. Instead of handling this all in the controller and having big nasty if blocks of logic, I would like to use a pattern to handle how this information gets ingested into our application. What are your opinions?

    Read the article

  • Single-Page Web Apps: Client-side datastores & server persistence

    - by fig-gnuton
    How should client-side datastores & persistence be handled in a single-page web application? Global vars vs. DI/IoC: Should datastores be assigned to global variables so any part of the application can access them? Or should they be dependency injected where required? Server persistence: Assuming a datastore's data needn't always be persisted to the server immediately, should the datastore itself handle persistence? If not, then what class should handle persistence and how should the persistence class fit into the client-side architecture overall? Is the datastore considered the model in MVC, or is it something else since it just stores raw data?

    Read the article

  • Better alternative to autonumber primary keys

    - by Comrad_Durandal
    I am looking for a better primary key than the autonumber data type, namely for the reason that it's limited to a long integer, when I really just need the field to reflect a number or text string that will never ever repeat, no matter HOW many records are added or deleted from the table. The problem is I am not sure how to implement something like turning the current date and time into a hexadecimal string and using that as a unique field I can use as a primary key. Am I just being too paranoid about running out of space?

    Read the article

  • What is the best way to store categorical references in SQL tables?

    - by jlafay
    I'm wanting to store a wide array of categorical data in MySQL database tables. Let's say that for instance I want to to information on "widgets" and want to categorize attributes in certain ways, i.e. shape category. For instance, the widgets could be classified as: round, square, triangular, spherical, etc. Should these categories be stored within a table to reference them best from an application? Another possibility, I would imagine, would be to add a column to widgets that contained a shape column that contained a tiny int. That way my application could search shapes by that and then use a coordinating enum type that would map the shape int meanings. Which would be best? Or is there another solution that I'm not thinking of yet?

    Read the article

  • 0/1 Knapsack with irrational weights

    - by user356106
    Consider the 0/1 knapsack problem. The standard Dynamic Programming algorithm applies only when the capacity as well as the weights to fill the knapsack with are integers/ rational numbers. What do you do when the capacity/weights are irrational? The issue is that we can't memoize like we do for integer weights because we may need potentially infinite decimal places for irrational weights - leading to an infinitely large number of columns for the Dynamic Programming Table . Is there any standard method for solving this? Any comments on the complexity of this problem? Any heuristics? What about associated recurrences like (for example): f(x)=1, for x< sqrt(2) f(x)=f(x-sqrt(2))+sqrt(3)

    Read the article

  • application specific seed data population

    - by user339108
    Env: JBoss, (h2, MySQl, postgres), JPA, Hibernate 3.3.x @Id @GeneratedValue(strategy = IDENTITY) private Integer key; Currently our primary keys are created using the above annotation. We expect to support a large number of users (~million users), what key should be used. Should it be Integer or Long or should I use the unsigned versions of the above declarations. We have a j2ee application which needs to be populated with some seed data on installation. On purchase, the customer creates his own data on top of the application. We just want to make sure that there is enough room to ship, modify or add data for future releases. What would be the best mechanism to support this, we had looked at starting all table identifiers from a certain id (say 1000) but this mandates modifying primary key generation to have table or sequence based generators and we have around ~100 tables. We are not sure if this is the right strategy for this. If we use a signed integer approach for the key, would it make sense to have the seed data as everything starting from 0 and below (i.e -ve numbers), so that all customer specific data will be available on 0 and above (i.e. +ve numbers)

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 226 227 228 229 230 231 232 233 234 235 236 237  | Next Page >