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  • Could any help me in resource of how to build framework with api like facebook ?

    - by Space Cracker
    we will develop a web site that will have some free services and we want to make it as a framework that can any build application over it or can use its api in their site .. Could any lead me in how to start it , what's the better architecture and design pattern help in that , is there any resources discuss or explain how to do like this ? FYI : we are dot net developers but we can learn any other if its urgently needed in such a solution

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  • In a DDD approach, is this example modelled correctly?

    - by Tag
    Just created an acc on SO to ask this :) Assuming this simplified example: building a web application to manage projects... The application has the following requirements/rules. 1) Users should be able to create projects inserting the project name. 2) Project names cannot be empty. 3) Two projects can't have the same name. I'm using a 4-layered architecture (User Interface, Application, Domain, Infrastructure). On my Application Layer i have the following ProjectService.cs class: public class ProjectService { private IProjectRepository ProjectRepo { get; set; } public ProjectService(IProjectRepository projectRepo) { ProjectRepo = projectRepo; } public void CreateNewProject(string name) { IList<Project> projects = ProjectRepo.GetProjectsByName(name); if (projects.Count > 0) throw new Exception("Project name already exists."); Project project = new Project(name); ProjectRepo.InsertProject(project); } } On my Domain Layer, i have the Project.cs class and the IProjectRepository.cs interface: public class Project { public int ProjectID { get; private set; } public string Name { get; private set; } public Project(string name) { ValidateName(name); Name = name; } private void ValidateName(string name) { if (name == null || name.Equals(string.Empty)) { throw new Exception("Project name cannot be empty or null."); } } } public interface IProjectRepository { void InsertProject(Project project); IList<Project> GetProjectsByName(string projectName); } On my Infrastructure layer, i have the implementation of IProjectRepository which does the actual querying (the code is irrelevant). I don't like two things about this design: 1) I've read that the repository interfaces should be a part of the domain but the implementations should not. That makes no sense to me since i think the domain shouldn't call the repository methods (persistence ignorance), that should be a responsability of the services in the application layer. (Something tells me i'm terribly wrong.) 2) The process of creating a new project involves two validations (not null and not duplicate). In my design above, those two validations are scattered in two different places making it harder (imho) to see whats going on. So, my question is, from a DDD perspective, is this modelled correctly or would you do it in a different way?

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  • Rails Controller

    - by Steve
    Hi...In Rails, is it ok to define logic in a controller with a model. For example, take there is an User Model, which is good design. 1)Leaving the UserModel with the CRUD models and moving all the other User Specific actions to a separate controller or 2)Add the user specific actions to the same UserModels Thanks :)

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  • Why can't my master page be loaded

    - by Irwin
    I've largely ignored this error, but i can do so no more. I'm trying to view a page that inherits from a master page in my solution, but I see this: "The Master Page file 'Site.master' cannot be loaded." The page exists, I can browse to it, view it in design view and do stuff. When the site is loaded in the browser, it works fine. Any ideas?

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  • Dynamic data-entry value store

    - by simendsjo
    I'm creating a data-entry application where users are allowed to create the entry schema. My first version of this just created a single table per entry schema with each entry spanning a single or multiple columns (for complex types) with the appropriate data type. This allowed for "fast" querying (on small datasets as I didn't index all columns) and simple synchronization where the data-entry was distributed on several databases. I'm not quite happy with this solution though; the only positive thing is the simplicity... I can only store a fixed number of columns. I need to create indexes on all columns. I need to recreate the table on schema changes. Some of my key design criterias are: Very fast querying (Using a simple domain specific query language) Writes doesn't have to be fast Many concurrent users Schemas will change often Schemas might contain many thousand columns The data-entries might be distributed and needs syncronization. Preferable MySQL and SQLite - Databases like DB2 and Oracle is out of the question. Using .Net/Mono I've been thinking of a couple of possible designs, but none of them seems like a good choice. Solution 1: Union like table containing a Type column and one nullable column per type. This avoids joins, but will definitly use a lot of space. Solution 2: Key/value store. All values are stored as string and converted when needed. Also use a lot of space, and of course, I hate having to convert everything to string. Solution 3: Use an xml database or store values as xml. Without any experience I would think this is quite slow (at least for the relational model unless there is some very good xpath support). I also would like to avoid an xml database as other parts of the application fits better as a relational model, and being able to join the data is helpful. I cannot help to think that someone has solved (some of) this already, but I'm unable to find anything. Not quite sure what to search for either... I know market research is doing something like this for their questionnaires, but there are few open source implementations, and the ones I've found doesn't quite fit the bill. PSPP has much of the logic I'm thinking of; primitive column types, many columns, many rows, fast querying and merging. Too bad it doesn't work against a database.. And of course... I don't need 99% of the provided functionality, but a lot of stuff not included. I'm not sure this is the right place to ask such a design related question, but I hope someone here has some tips, know of any existing work, or can point me to a better place to ask such a question. Thanks in advance!

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  • Database normalization question

    - by chchrist
    Hi all, I am trying to make a fashion boutique site. In this site each product (t-shirt,jeans etc) belongs to a collection. Each collection has looks (t-shirt,jean,accessories). A product can belong to one collection and to multiple looks. How should I design the database?

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  • What are the benefits of prototypal inheritance over classical?

    - by Pierreten
    So I finally stopped dragging my feet all these years and decided to learn JavaScript "properly". One of the most head-scratching elements of the languages design is it's implementation of inheritance. Having experience in Ruby, I was really happy to see closures and dynamic typing; but for the life of me can't figure out what benefits are to be had from object instances using other instances for inheritance.

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  • Discovering a functional algorithm from a mutable one

    - by Garrett Rowe
    This isn't necessarily a Scala question, it's a design question that has to do with avoiding mutable state, functional thinking and that sort. It just happens that I'm using Scala. Given this set of requirements: Input comes from an essentially infinite stream of random numbers between 1 and 10 Final output is either SUCCEED or FAIL There can be multiple objects 'listening' to the stream at any particular time, and they can begin listening at different times so they all may have a different concept of the 'first' number; therefore listeners to the stream need to be decoupled from the stream itself. Pseudocode: if (first number == 1) SUCCEED else if (first number >= 9) FAIL else { first = first number rest = rest of stream for each (n in rest) { if (n == 1) FAIL else if (n == first) SUCCEED else continue } } Here is a possible mutable implementation: sealed trait Result case object Fail extends Result case object Succeed extends Result case object NoResult extends Result class StreamListener { private var target: Option[Int] = None def evaluate(n: Int): Result = target match { case None => if (n == 1) Succeed else if (n >= 9) Fail else { target = Some(n) NoResult } case Some(t) => if (n == t) Succeed else if (n == 1) Fail else NoResult } } This will work but smells to me. StreamListener.evaluate is not referentially transparent. And the use of the NoResult token just doesn't feel right. It does have the advantage though of being clear and easy to use/code. Besides there has to be a functional solution to this right? I've come up with 2 other possible options: Having evaluate return a (possibly new) StreamListener, but this means I would have to make Result a subtype of StreamListener which doesn't feel right. Letting evaluate take a Stream[Int] as a parameter and letting the StreamListener be in charge of consuming as much of the Stream as it needs to determine failure or success. The problem I see with this approach is that the class that registers the listeners should query each listener after each number is generated and take appropriate action immediately upon failure or success. With this approach, I don't see how that could happen since each listener is forcing evaluation of the Stream until it completes evaluation. There is no concept here of a single number generation. Is there any standard scala/fp idiom I'm overlooking here?

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  • Is Programming or web designing a site harder? [closed]

    - by ggfan
    Given that someone has almost an equal understanding of coding(java, php, etc) and web designing(css, xml, photoshop) and wants to create a functional site. Which generally would be more time-consuming. There is obviously lots of considerations...but in general Just curious, because i am learning everything from books and now putting coding and design into practice and the css is kicking my *.

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  • Returning Json object from controller action to jQuery

    - by PsychoCoder
    I'm attempting to get this working properly (2 days now). I'm working on a log in where I'm calling the controller action from jQuery, passing it a JSON object (utilizing json2.js) and returning a Json object from the controller. I'm able to call the action fine, but instead of being able to put the response where I want it it just opens a new window with this printed on the screen: {"Message":"Invalid username/password combination"} And the URL looks like http://localhost:13719/Account/LogOn so instead of calling the action and not reloading the page it's taking the user to the controller, which isn't good. So now for some code, first the controller code [HttpPost] public ActionResult LogOn(LogOnModel model, string returnUrl = "") { if (ModelState.IsValid) { var login = ObjectFactory.GetInstance<IRepository<PhotographerLogin>>(); var user = login.FindOne(x => x.Login == model.Username && x.Pwd == model.Password); if (user == null) return Json(new FailedLoginViewModel { Message = "Invalid username/password combination" }); else { if (!string.IsNullOrEmpty(returnUrl)) return Redirect(returnUrl); else return RedirectToAction("Index", "Home"); } } return RedirectToAction("Index", "Home"); } And the jQuery code $("#signin_submit").click(function () { var login = getLogin(); $.ajax({ type: "POST", url: "../Account/LogOn", data: JSON.stringify(login), dataType: 'json', contentType: 'application/json; charset=utf-8', error: function (xhr) { $("#message").text(xhr.statusText); }, success: function (result) { } }); }); function getLogin() { var un = $("#username").val(); var pwd = $("#password").val(); var rememberMe = $("#rememberme").val(); return (un == "") ? null : { Username: un, Password: pwd, RememberMe: rememberMe }; } In case you need to see the actual login form here that is as well <fieldset id="signin_menu"> <div> <span id="message"></span> </div> <% Html.EnableClientValidation(); %> <% using (Html.BeginForm("LogOn", "Account", FormMethod.Post, new { @id = "signin" })) {%> <% ViewContext.FormContext.ValidationSummaryId = "valLogOnContainer"; %> <%= Html.LabelFor(m => m.Username) %> <%= Html.TextBoxFor(m => m.Username, new { @class = "inputbox", @tabindex = "4", @id = "username" })%><%= Html.ValidationMessageFor(m => m.Username, "*")%> <p> <%= Html.LabelFor(m=>m.Password) %> <%= Html.PasswordFor(m => m.Password, new { @class = "inputbox", @tabindex = "5", @id = "password" })%><%= Html.ValidationMessageFor(m => m.Password, "*")%> </p> <p class="remember"> <input id="signin_submit" value="Sign in" tabindex="6" type="submit"/> <%= Html.CheckBoxFor(m => m.RememberMe, new { @class = "inputbox", @tabindex = "7", @id = "rememberme" })%> <%= Html.LabelFor(m => m.RememberMe) %> <p class="forgot"> <a href="#" id="forgot_password_link" title="Click here to reset your password.">Forgot your password?</a> </p> <p class="forgot-username"> <a href="#" id="forgot_username_link" title="Fogot your login name? We can help with that">Forgot your username?</a> </p> </p> <%= Html.ValidationSummaryJQuery("Please fix the following errors.", new Dictionary<string, object> { { "id", "valLogOnContainer" } })%> <% } %> </fieldset> The login form is loaded on the main page with <% Html.RenderPartial("LogonControl");%> Not sure if that has any bearing on this or not but thought I'd mention it. EDIT: The login form is loaded similar to the Twitter login, click a link and the form loads with the help of jQuery & CSS

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  • What are the reasons *not* to use a GUID for a primary key?

    - by Yarin
    Whenever I design a database I automatically start with an auto-generating GUID primary key for each of my tables (excepting look-up tables) I know I'll never lose sleep over duplicate keys, merging tables, etc. To me it just makes sense philosophically that any given record should be unique across all domains, and that that uniqueness should be represented in a consistent way from table to table. I realize it will never be the most performant option, but putting performance aside, I'd like to know if there are philosophical arguments against this practice?

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  • Are GUID primary keys bad in theory, or just practice?

    - by Yarin
    Whenever I design a database I automatically start with an auto-generating GUID primary key for each of my tables (excepting look-up tables) I know I'll never lose sleep over duplicate keys, merging tables, etc. To me it just makes sense philosophically that any given record should be unique across all domains, and that that uniqueness should be represented in a consistent way from table to table. I realize it will never be the most performant option, but putting performance aside, I'd like to know if there are philosophical arguments against this practice?

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  • how to develop a program to minimize errors in human transcription of hand written surveys

    - by Alex. S.
    I need to develop custom software to do surveys. Questions may be of multiple choice, or free text in a very few cases. I was asked to design a subsystem to check if there is any error in the manual data entry for the multiple choices part. We're trying to speed up the user data entry process and to minimize human input differences between digital forms and the original questionnaires. The surveys are filled with handwritten marks and text by human interviewers, so it's possible to find hard to read marks, or also the user could accidentally select a different value in some question, and we would like to avoid that. The software must include some automatic control to detect possible typing differences. Each answer of the multiple choice questions has the same probability of being selected. This question has two parts: The GUI. The most simple thing I have in mind is to implement the most usable design of the questions display: use of large and readable fonts and space generously the choices. Is there something else? For faster input, I would like to use drop down lists (favoring keyboard over mouse). Given the questions are grouped in sections, I would like to show the answers selected for the questions of that section, but this could slow down the process. Any other ideas? The error checking subsystem. What else can I do to minimize or to check human typos in the multiple choice questions? Is this a solvable problem? is there some statistical methodology to check values that were entered by the users are the same from the hand filled forms? For example, let's suppose the survey has 5 questions, and each has 4 options. Let's say I have n survey forms filled in paper by interviewers, and they're ready to be entered in the software, then how to minimize the accidental differences that can have the manual transcription of the n surveys, without having to double check everything in the 5 questions of the n surveys? My first suggestion is that at the end of the processing of all the hand filled forms, the software could choose some forms randomly to make a double check of the responses in a few instances, but on what criteria can I make this selection? This validation would be enough to cover everything in a significant way? The actual survey is nation level and it has 56 pages with over 200 questions in total, so it will be a lot of hand written pages by many people, and the intention is to reduce the likelihood of errors and to optimize speed in the data entry process. The surveys must filled in paper first, given the complications of taking laptops or handhelds with the interviewers.

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  • OOP App Architecture: Which layer does a lazy loader sit in?

    - by JW
    I am planning the implemention an Inheritance Mapper pattern for an application component http://martinfowler.com/eaaCatalog/inheritanceMappers.html One feature it needs to have is for a domain object to reference a large list of aggreageted items (10,000 other domain objects) So I need some kind of lazy loading collection to be passed out of the aggregate root domain object to other domain objects. To keep my (php) model scripts organised i am storing them in two folders: MyComponent\ controllers\ models\ domain\ <- domain objects, DDD repository, DDD factory daccess\ <- PoEAA data mappers, SQL queries etc views\ But now I am racking my brains wondering where my lazy loading collection sits. Any suggestions / justifications for putting it in one place over another another? DDD = Domain Driven Design Patterns, Eric Evans - book PoEAA = Patterns of Application Architecture Patterns, Martin Fowler - book

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  • Is it necessary to look, website same in all browser?

    - by metal-gear-solid
    Is it necessary to look, website same in all browser? are some client mad? isn't it need of pixel perfection ( to inch to inch match with Design) a madness? isn't it asking IE6 Pixel perfection, as of now, is a madness? Is it sin to to use JavaScript for visual enhancement, like to enable border radius in IE using Javascript and from CSS in other browsers?

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  • Problems Enforcing Referential Integrity on SQL Server Tables

    - by SidC
    Hello All, I have a SQL Server 2005 database comprised of Customer, Quote, QuoteDetail tables. I want/need to enforce referential integrity such that when an insert is made on quotedetail, the quote and customer tables are also affected. I have tried my best to set up primary/foreign keys on my tables but need some help. Here's the scripts for my tables as they stand now (please don't laugh): Customers: USE [Diel_inventory] GO /****** Object: Table [dbo].[Customers] Script Date: 05/08/2010 03:39:04 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Customers]( [pkCustID] [int] IDENTITY(1,1) NOT NULL, [CompanyName] [nvarchar](50) NULL, [Address] [nvarchar](50) NULL, [City] [nvarchar](50) NULL, [State] [nvarchar](2) NULL, [ZipCode] [nvarchar](5) NULL, [OfficePhone] [nvarchar](12) NULL, [OfficeFAX] [nvarchar](12) NULL, [Email] [nvarchar](50) NULL, [PrimaryContactName] [nvarchar](50) NULL, CONSTRAINT [PK_Customers] PRIMARY KEY CLUSTERED ([pkCustID] ASC)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] Quotes: USE [Diel_inventory] GO /****** Object: Table [dbo].[Quotes] Script Date: 05/08/2010 03:30:46 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Quotes]( [pkQuoteID] [int] IDENTITY(1,1) NOT NULL, [fkCustomerID] [int] NOT NULL, [QuoteDate] [timestamp] NOT NULL, [NeedbyDate] [datetime] NULL, [QuoteAmt] [decimal](6, 2) NOT NULL, [QuoteApproved] [bit] NOT NULL, [fkOrderID] [int] NOT NULL, CONSTRAINT [PK_Bids] PRIMARY KEY CLUSTERED ( [pkQuoteID] ASC)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] GO ALTER TABLE [dbo].[Quotes] WITH CHECK ADD CONSTRAINT [fkCustomerID] FOREIGN KEY([fkCustomerID]) REFERENCES [dbo].[Customers] ([pkCustID]) GO ALTER TABLE [dbo].[Quotes] CHECK CONSTRAINT [fkCustomerID] QuoteDetail: USE [Diel_inventory] GO /****** Object: Table [dbo].[QuoteDetail] Script Date: 05/08/2010 03:31:58 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[QuoteDetail]( [ID] [int] IDENTITY(1,1) NOT NULL, [fkQuoteID] [int] NOT NULL, [fkCustomerID] [int] NOT NULL, [fkPartID] [int] NULL, [PartNumber1] [float] NOT NULL, [Qty1] [int] NOT NULL, [PartNumber2] [float] NULL, [Qty2] [int] NULL, [PartNumber3] [float] NULL, [Qty3] [int] NULL, [PartNumber4] [float] NULL, [Qty4] [int] NULL, [PartNumber5] [float] NULL, [Qty5] [int] NULL, [PartNumber6] [float] NULL, [Qty6] [int] NULL, [PartNumber7] [float] NULL, [Qty7] [int] NULL, [PartNumber8] [float] NULL, [Qty8] [int] NULL, [PartNumber9] [float] NULL, [Qty9] [int] NULL, [PartNumber10] [float] NULL, [Qty10] [int] NULL, [PartNumber11] [float] NULL, [Qty11] [int] NULL, [PartNumber12] [float] NULL, [Qty12] [int] NULL, [PartNumber13] [float] NULL, [Qty13] [int] NULL, [PartNumber14] [float] NULL, [Qty14] [int] NULL, [PartNumber15] [float] NULL, [Qty15] [int] NULL, [PartNumber16] [float] NULL, [Qty16] [int] NULL, [PartNumber17] [float] NULL, [Qty17] [int] NULL, [PartNumber18] [float] NULL, [Qty18] [int] NULL, [PartNumber19] [float] NULL, [Qty19] [int] NULL, [PartNumber20] [float] NULL, [Qty20] [int] NULL, CONSTRAINT [PK_QuoteDetail] PRIMARY KEY CLUSTERED ( [ID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] GO ALTER TABLE [dbo].[QuoteDetail] WITH CHECK ADD CONSTRAINT [FK_QuoteDetail_Customers] FOREIGN KEY ([fkCustomerID]) REFERENCES [dbo].[Customers] ([pkCustID]) GO ALTER TABLE [dbo].[QuoteDetail] CHECK CONSTRAINT [FK_QuoteDetail_Customers] GO ALTER TABLE [dbo].[QuoteDetail] WITH CHECK ADD CONSTRAINT [FK_QuoteDetail_PartList] FOREIGN KEY ([fkPartID]) REFERENCES [dbo].[PartList] ([RecID]) GO ALTER TABLE [dbo].[QuoteDetail] CHECK CONSTRAINT [FK_QuoteDetail_PartList] GO ALTER TABLE [dbo].[QuoteDetail] WITH CHECK ADD CONSTRAINT [FK_QuoteDetail_Quotes] FOREIGN KEY([fkQuoteID]) REFERENCES [dbo].[Quotes] ([pkQuoteID]) GO ALTER TABLE [dbo].[QuoteDetail] CHECK CONSTRAINT [FK_QuoteDetail_Quotes] Your advice/guidance on how to set these up so that customer ID in Customers is the same as in Quotes (referential integrity) and that CustomerID is inserted on Quotes and Customers when an insert is made to QuoteDetial would be much appreciated. Thanks, Sid

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  • Objective C Object Functioning & Passing Arrays

    - by Patrick
    I apologise if this has been asked before but I can't find the info I need. Basically I want a UITableView to be populated using info from a server, similar to the SeismicXML example. I have the parser as a separate object, is it correct to alloc, init an instance of that parser & then tell RootViewController to make it's table data source a copy of the parser's array. I can't include code because I haven't written anything yet, I'm just trying to get the design right before I start. Perhaps something like: xmlParser = [[XMLParser alloc] init]; [xmlParser getXMLData]; // Assuming xmlParser stores results in an array called returnedArray self.tableDataSource = xmlParser.returnedArray Is this the best way of doing it?

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