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  • iphone: caching and updating xml fields

    - by pJosh
    Thanks for your help. Here I have another question. I get the data through XMLParsing, now I want to store it in iphone's cache, and the XML Fields are updates every 12 hours.how can i check that XML Fields are change or not? and how can I store the data in iphone's cache memory so that evry it does not has to interact with web. Can anybody please help me???

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  • Choosing colour schemes

    - by DanDan
    How do you choose your colour schemes for your applications and/or web designs? Is it a gut instinct thing or can logic be applied here too? I have looked at some colour theory but my combinations seemed wrong. I am looking at a monochrome webpage. Rather than pluck colours out of the air as usual I would like to see if there is a science behind this. Links and opinions welcome.

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  • servlet does not envoke when I call a from method.

    - by saloni
    My web.xml is like <web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> <display-name>sample</display-name> <servlet> <servlet-name>Sampleclass</servlet-name> <servlet-class>sample.SampleClass</servlet-class> </servlet> <servlet-mapping> <servlet-name>Sampleclass</servlet-name> <url-pattern>/SampleClass</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>/page/form.jsp</welcome-file> </welcome-file-list> </web-app> and form.jsp <%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Insert title here</title> </head> <body> <h1>A simple web application</h1> <form method="POST" name="Sampleclass" action="SampleClass"> <label for="name">Enter your name </label> <input type="text" id="name" name="name"/><br><br> <input type="submit" value="Submit Form"/> <input type="reset" value="Reset Form"/> </form> </body> </html> and SampleClass.java is public class SampleClass extends HttpServlet { public void init(ServletConfig config) throws ServletException { super.init(config); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String name = request.getParameter("name"); String age = request.getParameter("age"); PrintWriter out = response.getWriter(); out.write("<html>Hello Your name is "+name +", and your age is "+age+"</html>"); } public void destroy() { } } but I am getting error when I entered to submit button of form.jsp and error is type Status report message HTTP method POST is not supported by this URL description The specified HTTP method is not allowed for the requested resource (HTTP method POST is not supported by this URL). I am not understanding that what is the problem exactly ? Please help..

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  • Text -> Diagram Tool

    - by Jon
    I'm looking for an diagram tool for producing diagrams from text. I only really need sequence and state type diagrams for now, but I'm curious as to what people would recommend? I need something which is standalone, not a web based tool that works on Linux, OSX and Windows.

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  • Understanding colors

    - by Ankur Gupta
    Hello everyone, Kindly point towards theory/material to read for understanding colors and what makes a good color combinations. Mind it that I am not interested in say "Color combinations for web application" etc. More of the lines of say "Colors and humans". Material free to read is what i am looking for. Thanks

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  • Unable to connect SQL Server instance from Visual Studio 2008 Version 9.0

    - by salvationishere
    I am getting the below error from VS on an 32-bit XP Professional server even though I set Tools-Options-Database Tools-Data Connections to "SIDEKICK", which is the name of my computer. In other words SIDEKICK should default to the full SQLSERVER. In other words, I want VS to use SQLSERVER instead of SQLSERVER EXPRESS. And I can clearly see my database both from VS in the Server Explorer and also in SSMS 2008. Furthermore, I can view the tables of this database in Server Explorer from VS. I do not get any build errors. And it looks like all of the naming is consistent in my web.config file. I am developing my website according to a Microsoft tutorial, so I should not be getting an error. Yet I get the following exception when I run this code below: CreateAccounts.aspx.cs file protected void CreateAccountButton_Click(object sender, EventArgs e) { MembershipCreateStatus createStatus; //This line below is where the exception occurs MembershipUser newUser = Membership.CreateUser(Username.Text, Password.Text, Email.Text, passwordQuestion, SecurityAnswer.Text, true, out createStatus); And here is what the exception looks like: System.Web.HttpException was unhandled by user code Message="Unable to connect to SQL Server database." Source="System.Web" ErrorCode=-2147467259 StackTrace: at System.Web.DataAccess.SqlConnectionHelper.CreateMdfFile(String fullFileName, String dataDir, String connectionString) at System.Web.DataAccess.SqlConnectionHelper.EnsureSqlExpressDBFile(String connectionString) at System.Web.DataAccess.SqlConnectionHelper.GetConnection(String connectionString, Boolean revertImpersonation) at System.Web.Security.SqlMembershipProvider.CreateUser(String username, String password, String email, String passwordQuestion, String passwordAnswer, Boolean isApproved, Object providerUserKey, MembershipCreateStatus& status) at System.Web.Security.Membership.CreateUser(String username, String password, String email, String passwordQuestion, String passwordAnswer, Boolean isApproved, Object providerUserKey, MembershipCreateStatus& status) at System.Web.Security.Membership.CreateUser(String username, String password, String email, String passwordQuestion, String passwordAnswer, Boolean isApproved, MembershipCreateStatus& status) at Membership_CreatingUserAccounts.CreateAccountButton_Click(Object sender, EventArgs e) in c:\Documents and Settings\Admin\My Documents\Visual Studio 2008\WebSites\WebSite2\Membership\CreatingUserAccounts.aspx.cs:line 24 at System.Web.UI.WebControls.Button.OnClick(EventArgs e) at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) InnerException: System.Web.HttpException Message="Unable to connect to SQL Server database." Source="System.Web" ErrorCode=-2147467259 StackTrace: at System.Web.Management.SqlServices.GetSqlConnection(String server, String user, String password, Boolean trusted, String connectionString) at System.Web.Management.SqlServices.SetupApplicationServices(String server, String user, String password, Boolean trusted, String connectionString, String database, String dbFileName, SqlFeatures features, Boolean install) at System.Web.Management.SqlServices.Install(String database, String dbFileName, String connectionString) at System.Web.DataAccess.SqlConnectionHelper.CreateMdfFile(String fullFileName, String dataDir, String connectionString) InnerException: System.Data.SqlClient.SqlException Message="The user instance login flag is not supported on this version of SQL Server. The connection will be closed." Source=".Net SqlClient Data Provider" ErrorCode=-2146232060 Class=14 LineNumber=65536 Number=18493 Procedure="" Server="." State=1 StackTrace: at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) at System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK) at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject) at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart) at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.SqlClient.SqlConnection.Open() at System.Web.Management.SqlServices.GetSqlConnection(String server, String user, String password, Boolean trusted, String connectionString) InnerException: The web.config connection string looks like: <connectionStrings> <add name="SecurityTutorialsConnectionString" connectionString="data source=.;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|SecurityTutorialsDatabase3.mdf;User Instance=true" providerName="System.Data.SqlClient"/> </connectionStrings> <system.web> <membership defaultProvider="SecurityTutorialsSqlMembershipProvider"> <providers> <add name="SecurityTutorialsSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="SecurityTutorialsConnectionString" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="true" applicationName="SecurityTutorials" requiresUniqueEmail="true" passwordFormat="Hashed" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="7" minRequiredNonalphanumericCharacters="1" passwordAttemptWindow="10" passwordStrengthRegularExpression=""/> </providers> </membership>

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  • How do I recover from an unchecked exception?

    - by erickson
    Unchecked exceptions are alright if you want to handle every failure the same way, for example by logging it and skipping to the next request, displaying a message to the user and handling the next event, etc. If this is my use case, all I have to do is catch some general exception type at a high level in my system, and handle everything the same way. But I want to recover from specific problems, and I'm not sure the best way to approach it with unchecked exceptions. Here is a concrete example. Suppose I have a web application, built using Struts2 and Hibernate. If an exception bubbles up to my "action", I log it, and display a pretty apology to the user. But one of the functions of my web application is creating new user accounts, that require a unique user name. If a user picks a name that already exists, Hibernate throws an org.hibernate.exception.ConstraintViolationException (an unchecked exception) down in the guts of my system. I'd really like to recover from this particular problem by asking the user to choose another user name, rather than giving them the same "we logged your problem but for now you're hosed" message. Here are a few points to consider: There a lot of people creating accounts simultaneously. I don't want to lock the whole user table between a "SELECT" to see if the name exists and an "INSERT" if it doesn't. In the case of relational databases, there might be some tricks to work around this, but what I'm really interested in is the general case where pre-checking for an exception won't work because of a fundamental race condition. Same thing could apply to looking for a file on the file system, etc. Given my CTO's propensity for drive-by management induced by reading technology columns in "Inc.", I need a layer of indirection around the persistence mechanism so that I can throw out Hibernate and use Kodo, or whatever, without changing anything except the lowest layer of persistence code. As a matter of fact, there are several such layers of abstraction in my system. How can I prevent them from leaking in spite of unchecked exceptions? One of the declaimed weaknesses of checked exceptions is having to "handle" them in every call on the stack—either by declaring that a calling method throws them, or by catching them and handling them. Handling them often means wrapping them in another checked exception of a type appropriate to the level of abstraction. So, for example, in checked-exception land, a file-system–based implementation of my UserRegistry might catch IOException, while a database implementation would catch SQLException, but both would throw a UserNotFoundException that hides the underlying implementation. How do I take advantage of unchecked exceptions, sparing myself of the burden of this wrapping at each layer, without leaking implementation details?

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  • Automatically reporting javascript errors to the developer

    - by Cine
    As most production environments we have setup something to send us a notification if there is an error in our web application. The problem is ofcourse that this only covers errors on the server side. My question to the community is: What are you doing about client side errors, especially in javascript? And what about other quality of service issues, such as slow processing and other things that might be due to the client machine?

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  • How to extend a large website to an iPhone app?

    - by xoail
    I am trying to create an iPhone app for a large website (as big as amazon.com) and it involves using cookies and what not to get authenticated via the Apache intercepter and access the web services exposed by the main website. For that I am looking for strategies to go about developing it. I am new to iPhone development and I am mostly looking for some architectural guidance. Does anyone know how services like eBay and Amazon work seamlessly across the website and iPhone app?

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  • Questions about .NET CollectionEditor type

    - by smwikipedia
    Who can tell me the internal working mechanism of a CollectionEditor in plain English? I have implemented every virtual function and step into each of them. Still got no clue of its intended algorithm. I searched the web and found tons of compaints about the CollectionEditor type, and even bugs. I am kind of thinking of the CollectionEditor as a total mess.

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  • ASCII Diagram Tool

    - by Jon
    I'm looking for an ASCII diagram tool for producing diagrams from text. I only really need sequence and state type diagrams for now, but I'm curious as to what people would recommend? I need something which is standalone, not a web based tool that works on Linux, OSX and Windows.

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  • Photoshop and Saving Quality

    - by ITg
    I'm making a simple image for the web which is a gradient with some text on in Photoshop CS4. The text doesn't seem to be of a great quality. If you look at the logo of stackoverflow you can see that its pretty accurate. Mine don't seem to render properly round the edges. Anyone know how to get the best quality? Photoshop CS4. Thanks.

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  • Web service client receiving generic FaultException rather than FaultException<T>

    - by Junto
    I am connecting to a Java Axis2 web service using a .NET web service client. The client itself targets the .NET 3.5 framework. The application that wraps the client DLL is 2.0. I'm not sure if that has any bearing. I have been given the WSDL and XSDs by email. From those I have built my proxy class using svcutil. Although I am able to successfully send messages, I am unable to pick up the correct faults when something goes wrong. In the example below, errors are always being picked up by the generic FaultException. catch (FaultException<InvoiceErrorType> fex) { OnLog(enLogLevel.ERROR, fex.Detail.ErrorDescription); } catch (FaultException gfex) { OnLog(enLogLevel.ERROR, gfex.Message); } The proxy client appears to have the appropriate attributes for the FaultContract: // CODEGEN: Generating message contract since the operation SendInvoiceProvider_Prod is neither RPC nor document wrapped. [OperationContractAttribute(Action = "https://private/SendInvoiceProvider", ReplyAction = "*")] [FaultContractAttribute(typeof(InvoiceErrorType), Action = "https://private/SendInvoiceProvider", Name = "InvoiceError", Namespace = "urn:company:schema:entities:base")] [XmlSerializerFormatAttribute(SupportFaults = true)] [ServiceKnownTypeAttribute(typeof(ItemDetail))] [ServiceKnownTypeAttribute(typeof(Supplier))] OutboundComponent.SendInvoiceProviderResponse SendInvoiceProvider_Prod(OutboundComponent.SendInvoiceProvider_Request request); I have enabled tracing and I can see the content of the fault coming back, but .NET is not recognizing it as an InvoiceError. The SOAP fault in full is: <soapenv:Fault> <faultcode xmlns="">soapenv:Client</faultcode> <faultstring xmlns="">Message found to be invalid</faultstring> <faultactor xmlns="">urn:SendInvoiceProvider</faultactor> <detail xmlns=""> <InvoiceError xmlns="urn:company:schema:entities:common:invoiceerror:v01"> <ErrorID>100040</ErrorID> <ErrorType>UNEXPECTED</ErrorType> <ErrorDescription>&lt;![CDATA[&lt;error xmlns="urn:company:schema:errordetail:v01"&gt;&lt;errorCode&gt;1000&lt;/errorCode&gt;&lt;highestSeverity&gt;8&lt;/highestSeverity&gt;&lt;errorDetails count="1"&gt;&lt;errorDetail&gt;&lt;errorType&gt;1&lt;/errorType&gt;&lt;errorSeverity&gt;8&lt;/errorSeverity&gt;&lt;errorDescription&gt;cvc-complex-type.2.4.a: Invalid content was found starting with element 'CompanyName'. One of '{"urn:company:schema:sendinvoice:rq:v01":RoleType}' is expected.&lt;/errorDescription&gt;&lt;errorNamespace&gt;urn:company:schema:sendinvoice:rq:v01&lt;/errorNamespace&gt;&lt;errorNode&gt;CompanyName&lt;/errorNode&gt;&lt;errorLine&gt;1&lt;/errorLine&gt;&lt;errorColumn&gt;2556&lt;/errorColumn&gt;&lt;errorXPath/&gt;&lt;errorSource/&gt;&lt;/errorDetail&gt;&lt;/errorDetails&gt;&lt;/error&gt;]]&gt;</ErrorDescription> <TimeStamp>2010-05-04T21:12:10Z</TimeStamp> </InvoiceError> </detail> </soapenv:Fault> I have noticed the namespace defined on the error: <InvoiceError xmlns="urn:company:schema:entities:common:invoiceerror:v01"> This is nowhere to be seen in the generated proxy class, nor in the WSDLs. The interface WSDL defines the error schema namespace as such: <xs:import namespace="urn:company:schema:entities:base" schemaLocation="InvoiceError.xsd"/> Could this be the reason why the .NET client is not able to parse the typed Fault Exception correctly? I have no control over the web service itself. I see no reason why .NET can't talk to a Java Axis2 web service. This user had a similar issue, but the reason for his problem cannot be the same as mine, since I can see the fault detail in the trace: http://stackoverflow.com/questions/864800/does-wcf-faultexceptiont-support-interop-with-a-java-web-service-fault Any help would be gratefully received.

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  • Online graphing and data visualization frameworks

    - by Marques
    I have been looking around at web applications and websites with rich graphs, charts, and data visualization and for the most part have been able to determine which frameworks or tools websites are using. However I was looking over 'resumup.com' and couldn't determine what they are using. Does anyone know off hand or can you tell? It doesn't seem like any javascript framework i've seen unless its custom...is it some sort of flash or flex framework? Any help would be greatly appreciated. Thanks, Marques

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  • Accessing the "super of this" in Java

    - by gerdemb
    This is what I'm doing now. Is there a better way to access the super class? public class SearchWidget { private void addWishlistButton() { final SearchWidget thisWidget = this; button.addClickHandler(new ClickHandler() { public void onClick(ClickEvent event) { // A better way to access the super class? // something like "this.super" ...? workWithWidget(thisWidget); } } } } I'm programming with Google Web Toolkit, but I think this is really a generic Java question.

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  • Session vs singleton pattern

    - by chobo
    Hi, I have a web application where I would like to pull user settings from a database and store them for Global access. Would it make more sense to store the data in a Singleton, or a Session object? What's the difference between the two? Is it better to store the data as an object reference or break it up into value type objects (ints and strings)? Thanks!

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  • How to Link VS2010 Database Project and LINQ to SQL

    - by Jason
    As I am working with the new database projects in VS2010, and as I am learning LINQ to SQL, I am curious as to the best way to link the two groups of information so that when I update one, the other updates along with it. From my research here at SO, as well as in Google, it appears the general rule of thumb is: "Build the database, and then create your LINQ to SQL classes." Of course, if I make a change in my database, the LINQ to SQL doesn't update automatically and I have to do it by hand. This is fairly simple right now as my database is small, but I am curious if there is an easier way for this to happen. In addition, the LINQ to SQL tool is pretty nice. The ability to create tables, add associations, and even create inheritance is very simple. As my second question, I am curious as to whether or not VS2010 can work the other way - I design the database in the DBLM file and then link it back to my database project. I appreciate any help with either of these two questions. I'm really interested in making this as easy as possible to reduce errors during development and improve the speed at which changes can be made.

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  • ReSharper - Possible Null Assignment when using Microsoft.Contracts

    - by HVS
    Is there any way to indicate to ReSharper that a null reference won't occur because of Design-by-Contract Requires checking? For example, the following code will raise the warning (Possible 'null' assignment to entity marked with 'NotNull' attribute) in ReSharper on lines 7 and 8: private Dictionary<string, string> _Lookup = new Dictionary<string, string>(); public void Foo(string s) { Contract.Requires(!String.IsNullOrEmpty(s)); if (_Lookup.ContainsKey(s)) _Lookup.Remove(s); } What is really odd is that if you remove the Contract.Requires(...) line, the ReSharper message goes away. Update I found the solution through ExternalAnnotations which was also mentioned by Mike below. Here's an example of how to do it for a function in Microsoft.Contracts: Create a directory called Microsoft.Contracts under the ExternalAnnotations ReSharper directory. Next, Create a file called Microsoft.Contracts.xml and populate like so: <assembly name="Microsoft.Contracts"> <member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)"> <attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/> <parameter name="condition"> <attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"> <argument>0</argument> </attribute> </parameter> </member> </assembly> Restart Visual Studio, and the message goes away!

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  • Database structure - is mySQL the right choice?

    - by Industrial
    Hi everyone, We are currently planning the database structure of a quite complex e-commerce web app that has flexibility as it's main cornerstone. Our app features a large amount of data (products) and we have run into a slight headache trying to keep performance high without compromizing normalization rules in the database, or leaving our highly beloved flexibility concept behind when integrating product options (also widely known as product attributes or parameters). Based on various references and sources available, we have made up lists on pros and cons of all major and well known database patterns to solve this. After comparing these, we have come up with two final alternatives: EAV (Entity-attribute-value model) : Pros: Database is used for all sorting. Cons: All related queries will include a number of joins between multiple tables in order to complete the collection of data. SLOB (Serialized LOB, also known as Facade?) : Pros: Very flexible. Keeping the number of necessary joins low compared to a EAV design pattern. Easy to update/add/remove data from each product. Cons: All sorting will be done by the application instead of the database. Will use lots of performance (memory?) when big datasets is processed by a large number of users. Our main questions: Which pattern/structure would you use, or maybe even a different solution? Is there better databases besides mySQL available nowadays to accomplish what we want? Thanks a lot! Reference: http://stackoverflow.com/questions/695752/product-table-many-kinds-of-product-each-product-has-many-parameters

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  • Invoice & Invoice lines: How do you store customer address information?

    - by elviejo
    Hi I'm developing an invoicing application. So the general idea is to have two tables: Invoice (ID, Date, CustomerAddress, CustomerState, CustomerCountry, VAT, Total); InvoiceLine (Invoice_ID, ID, Concept, Units, PricePerUnit, Total); As you can see this basic design leads to a lot of repetiton of records where the client will have the same addrres, state and country. So the alternative is to have an address table and then make a relationship Address<-Invoice. However I think that an invoice is immutable document and should be stored just the way it was first made. Sometimes customers change their addresses, or states and if it was coming from an Address catalog that will change all the previously made invoices. So What is your experience? How is the customer address stored in an invoice? In the Invoice table? an Address Table? or something else? Can you provide pointers to a book, article or document where this is discussed in further detail?

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  • DDD: Aggregate Roots

    - by Mosh
    Hello, I need help with finding my aggregate root and boundary. I have 3 Entities: Plan, PlannedRole and PlannedTraining. Each Plan can include many PlannedRoles and PlannedTrainings. Solution 1: At first I thought Plan is the aggregate root because PlannedRole and PlannedTraining do not make sense out of the context of a Plan. They are always within a plan. Also, we have a business rule that says each Plan can have a maximum of 3 PlannedRoles and 5 PlannedTrainings. So I thought by nominating the Plan as the aggregate root, I can enforce this invariant. However, we have a Search page where the user searches for Plans. The results shows a few properties of the Plan itself (and none of its PlannedRoles or PlannedTrainings). I thought if I have to load the entire aggregate, it would have a lot of overhead. There are nearly 3000 plans and each may have a few children. Loading all these objects together and then ignoring PlannedRoles and PlannedTrainings in the search page doesn't make sense to me. Solution 2: I just realized the user wants 2 more search pages where they can search for Planned Roles or Planned Trainings. That made me realize they are trying to access these objects independently and "out of" the context of Plan. So I thought I was wrong about my initial design and that is how I came up with this solution. So, I thought to have 3 aggregates here, 1 for each Entity. This approach enables me to search for each Entity independently and also resolves the performance issue in solution 1. However, using this approach I cannot enforce the invariant I mentioned earlier. There is also another invariant that states a Plan can be changed only if it is of a certain status. So, I shouldn't be able to add any PlannedRoles or PlannedTrainings to a Plan that is not in that status. Again, I can't enforce this invariant with the second approach. Any advice would be greatly appreciated. Cheers, Mosh

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  • Taking the data mapper approach in Zend Framework

    - by Seeker
    Let's assume the following tables setup for a Zend Framework app. user (id) groups (id) groups_users (id, user_id, group_id, join_date) I took the Data Mapper approach to models which basically gives me: Model_User, Model_UsersMapper, Model_DbTable_Users Model_Group, Model_GroupsMapper, Model_DbTable_Groups Model_GroupUser, Model_GroupsUsersMapper, Model_DbTable_GroupsUsers (for holding the relationships which can be seen as aentities; notice the "join_date" property) I'm defining the _referenceMap in Model_DbTable_GroupsUsers: protected $_referenceMap = array ( 'User' => array ( 'columns' => array('user_id'), 'refTableClass' => 'Model_DbTable_Users', 'refColumns' => array('id') ), 'App' => array ( 'columns' => array('group_id'), 'refTableClass' => 'Model_DbTable_Groups', 'refColumns' => array('id') ) ); I'm having these design problems in mind: 1) The Model_Group only mirrors the fields in the groups table. How can I return a collection of groups a user is a member of and also the date the user joined that group for every group? If I just added the property to the domain object, then I'd have to let the group mapper know about it, wouldn't I? 2) Let's say I need to fetch the groups a user belongs to. Where should I put this logic? Model_UsersMapper or Model_GroupsUsersMapper? I also want to make use of the referencing map (dependent tables) mechanism and probably use findManyToManyRowset or findDependentRowset, something like: $result = $this->getDbTable()->find($userId); $row = $result->current(); $groups = $row->findManyToManyRowset( 'Model_DbTable_Groups', 'Model_DbTable_GroupsUsers' ); This would produce two queries when I could have just written it in a single query. I will place this in the Model_GroupsUsersMapper class. An enhancement would be to add a getGroups method to the Model_User domain object which lazily loads the groups when needed by calling the appropriate method in the data mapper, which begs for the second question. Should I allow the domain object know about the data mapper?

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