Search Results

Search found 1555 results on 63 pages for 'mutiple inheritance'.

Page 56/63 | < Previous Page | 52 53 54 55 56 57 58 59 60 61 62 63  | Next Page >

• What is the best practice for using lock within inherited classes

  - by JDMX

  I want to know if one class is inheriting from another, is it better to have the classes share a lock object that is defined at the base class or to have a lock object defined at each inheritance level. A very simple example of a lock object on each level of the class public class Foo { private object thisLock = new object(); private int ivalue; public int Value { get { lock( thisLock ) { return ivalue; } } set { lock( thisLock ) { ivalue= value; } } } } public class Foo2: Foo { private object thisLock2 = new object(); public int DoubleValue { get { lock( thisLock2 ) { return base.Value * 2; } } set { lock( thisLock2 ) { base.Value = value / 2; } } } } public class Foo6: Foo2 { private object thisLock6 = new object(); public int TripleDoubleValue { get { lock( thisLock6 ) { return base.DoubleValue * 3; } } set { lock( thisLock6 ) { base.DoubleValue = value / 3; } } } } A very simple example of a shared lock object public class Foo { protected object thisLock = new object(); private int ivalue; public int Value { get { lock( thisLock ) { return ivalue; } } set { lock( thisLock ) { ivalue= value; } } } } public class Foo2: Foo { public int DoubleValue { get { lock( thisLock ) { return base.Value * 2; } } set { lock( thisLock ) { base.Value = value / 2; } } } } public class Foo6: Foo2 { public int TripleDoubleValue { get { lock( thisLock ) { return base.DoubleValue * 3; } } set { lock( thisLock ) { base.DoubleValue = value / 3; } } } } Which example is the preferred way to manage locking within an inherited class?

  Read the article

• executing stored procedure from Spring-Hibernate using Annotations

  - by HanuAthena

  I'm trying to execute a simple stored procedure with Spring/Hibernate using Annotations. Here are my code snippets: DAO class: public class UserDAO extends HibernateDaoSupport { public List selectUsers(final String eid){ return (List) getHibernateTemplate().execute(new HibernateCallback() { public Object doInHibernate(Session session) throws HibernateException, SQLException { Query q = session.getNamedQuery("SP_APPL_USER"); System.out.println(q); q.setString("eid", eid); return q.list(); } }); } } my entity class: @Entity @Table(name = "APPL_USER") @Inheritance(strategy = InheritanceType.SINGLE_TABLE) @DiscriminatorFormula(value = "SUBSCRIBER_IND") @DiscriminatorValue("N") @NamedQuery(name = "req.all", query = "select n from Requestor n") @org.hibernate.annotations.NamedNativeQuery(name = "SP_APPL_USER", query = "call SP_APPL_USER(?, :eid)", callable = true, readOnly = true, resultClass = Requestor.class) public class Requestor { @Id @Column(name = "EMPL_ID") public String getEmpid() { return empid; } public void setEmpid(String empid) { this.empid = empid; } @Column(name = "EMPL_FRST_NM") public String getFirstname() { return firstname; } ... } public class Test { public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext( "applicationContext.xml"); APFUser user = (APFUser)ctx.getBean("apfUser"); List selectUsers = user.getUserDAO().selectUsers("EMP456"); System.out.println(selectUsers); } } and the stored procedure: create or replace PROCEDURE SP_APPL_USER (p_cursor out sys_refcursor, eid in varchar2) as empId varchar2(8); fname varchar2(50); lname varchar2(50); begin empId := null; fname := null; lname := null; open p_cursor for select l.EMPL_ID, l.EMPL_FRST_NM, l.EMPL_LST_NM into empId, fname, lname from APPL_USER l where l.EMPL_ID = eid; end; If i enter invalid EID, its returning empty list which is OK. But when record is there, following exception is thrown: Exception in thread "main" org.springframework.jdbc.BadSqlGrammarException: Hibernate operation: could not execute query; bad SQL grammar [call SP_APPL_USER(?, ?)]; nested exception is java.sql.SQLException: Invalid column name Do I need to modify the entity(Requestor.class) ? How will the REFCURSOR be converted to the List? The stored procedure is expected to return more than one record.

  Read the article

• Why are all objects in this extension of usercontrol null at runtime?

  - by csciguy

  All, I have a simple class. public class Container : UserControl { public bool IsClickable { get; set; } } I have a class that extends this class. public class ScrollingContainer : Container { public void Draw() { } public void Update() { } } I have a custom class, that then extends ScrollingContainer. public partial class MaskContainer : ScrollingContainer { public MaskContainer() { InitializeComponent(); } } XAML <local:ScrollingContainer x:Class="Test.Types.MaskContainer" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:local="clr-namespace:GameObjects;assembly=GameObjects" mc:Ignorable="d" > </local:ScrollingContainer> In my mainpage.xaml, I have the following. <types:MaskContainer x:Name="maskContainer" Canvas.ZIndex="1" Width="Auto" Height="Auto"> <Canvas x:Name="maskCanvas"> <Button x:Name="button1" Content="test button"/> </Canvas> </types:MaskContainer> Why, at runtime, are both maskCanvas and button1 null? maskContainer is not null. The inheritance should be straightforward here. Container inherits usercontrol. Scrollable container inherits container. Mask Container inherits scrollable container. Why am I losing the fucntionality of the original base class at this level? Is it incorrect to add the element (button1) to the maskcontainer inside of the main.xaml? My end goal is to create a container that is reusable, but inherits all properties/methods that I've specified throughout the chain. Any help is appreciated.

  Read the article

• Can the Diamond Problem be really solved?

  - by Mecki

  A typical problem in OO programming is the diamond problem. I have parent class A with two sub-classes B and C. A has an abstract method, B and C implement it. Now I have a sub-class D, that inherits of B and C. The diamond problem is now, what implementation shall D use, the one of B or the one of C? People claim Java knows no diamond problem. I can only have multiple inheritance with interfaces and since they have no implementation, I have no diamond problem. Is this really true? I don't think so. See below: [removed vehicle example] Is a diamond problem always the cause of bad class design and something neither programmer nor compiler needs to solve, because it shouldn't exist in the first place? Update: Maybe my example was poorly chosen. See this image Of course you can make Person virtual in C++ and thus you will only have one instance of person in memory, but the real problem persists IMHO. How would you implement getDepartment() for GradTeachingFellow? Consider, he might be student in one department and teach in another one. So you can either return one department or the other one; there is no perfect solution to the problem and the fact that no implementation might be inherited (e.g. Student and Teacher could both be interfaces) doesn't seem to solve the problem to me.

  Read the article

• How to implement or emulate an "abstract" OCUnit test class?

  - by Quinn Taylor

  I have a number of Objective-C classes organized in an inheritance hierarchy. They all share a common parent which implements all the behaviors shared among the children. Each child class defines a few methods that make it work, and the parent class raises an exception for the methods designed to be implemented/overridden by its children. This effectively makes the parent a pseudo-abstract class (since it's useless on its own) even though Objective-C doesn't explicitly support abstract classes. The crux of this problem is that I'm unit testing this class hierarchy using OCUnit, and the tests are structured similarly: one test class that exercises the common behavior, with a subclass corresponding to each of the child classes under test. However, running the test cases on the (effectively abstract) parent class is problematic, since the unit tests will fail in spectacular fashion without the key methods. (The alternative of repeating the common tests across 5 test classes is not really an acceptable option.) The non-ideal solution I've been using is to check (in each test method) whether the instance is the parent test class, and bail out if it is. This leads to repeated code in every test method, a problem that becomes increasingly annoying if one's unit tests are highly granular. In addition, all such tests are still executed and reported as successes, skewing the number of meaningful tests that were actually run. What I'd prefer is a way to signal to OCUnit "Don't run any tests in this class, only run them in its child classes." To my knowledge, there isn't (yet) a way to do that, something similar to a +(BOOL)isAbstractTest method I can implement/override. Any ideas on a better way to solve this problem with minimal repetition? Does OCUnit have any ability to flag a test class in this way, or is it time to file a Radar? Edit: Here's a link to the test code in question. Notice the frequent repetition of if (...) return; to start a method, including use of the NonConcreteClass() macro for brevity.

  Read the article

• How to make designer generated .Net application settings portable

  - by Ville Koskinen

  Hello, I've been looking at modifying the source of the Doppler podcast aggregator with the goal of being able to run the program directly from my mp3 player. Doppler stores application settings using a Visual Studio designer generated Settings class, which by default serializes user settings to the user's home directory. I'd like to change this so that all settings would be stored in the same directory as the exe. It seems that this would be possible by creating a custom provider class which inherits the SettingsProvider class. Has anyone created such a provider and would like to share code? Update: I was able to get a custom settings provider nearly working by using this MSDN sample, i.e. with simple inheritance. I was initially confused as Windows Forms designer stopped working until I did this trick suggested at Codeproject: internal sealed partial class Settings { private MySettingsProvider settingsprovider = new MySettingsProvider(); public Settings() { foreach (SettingsProperty property in this.Properties) { property.Provider = settingsprovider; } ... The program still starts with window size 0;0 though. Anyone with any insight to this? Why the need to assing the provider in runtime---instead of using attributes as suggested by MSDN? Why the changes in how the default settings are passed to the application with the default settings provider vs. the custom one?

  Read the article

• How to get around the jslint error 'Don't make functions within a loop.'

  - by Ernelli

  I am working on making all of our JS code pass through jslint, sometimes with a lot of tweaking with the options to get legacy code pass for now on with the intention to fix it properly later. There is one thing that jslint complains about that I do not have a workround for. That is when using constructs like this, we get the error 'Don't make functions within a loop.' for (prop in newObject) { // Check if we're overwriting an existing function if (typeof newObject[prop] === "function" && typeof _super[prop] === "function" && fnTest.test(newObject[prop])) { prototype[prop] = (function (name, func) { return function () { var result, old_super; old_super = this._super; this._super = _super[name]; result = func.apply(this, arguments); this._super = old_super; return result; }; })(prop, newObject[prop]); } This loop is part of a JS implementation of classical inheritance where classes that extend existing classes retain the super property of the extended class when invoking a member of the extended class. Just to clarify, the implementation above is inspired by this blog post by John Resig. But we also have other instances of functions created within a loop. The only workaround so far is to exclude these JS files from jslint, but we would like to use jslint for code validation and syntax checking as part of our continuous integration and build workflow. Is there a better way to implement functionality like this or is there a way to tweak code like this through jslint?

  Read the article

• Entity Framework - Foreign key constraints not added for inherited entity

  - by Tri Q

  Hello, It appears to me that a strange phenomenon is occurring with inherited entities (TPT) in EF4. I have three entities. 1. Asset 2. Property 3. Activity Property is a derived-type of Asset. Property has many activities (many-to-many) When modeling this in my EDMX, everything seems fine until I try to insert a new Property into the database. If the property does not contain any Activity, it works, but all hell breaks loose when I add some new activities to the new Property. As it turns out after 2 days of crawling the web and fiddling around, I noticed that in the EF store (SSDL) some of the constraints between entities were not picked up during the update process. Property_Activity table which links properties and activities show only one constraint FK_Property_Activity_Activity but FK_Property_Activity_Property was missing. I knew this is an Entity Framework anomoly because when I switched the relationship in the database to: Asset <-- Asset_Activity <-- Activity After an update, all foreign key constraints are picked up and the save is successful, with or without activities in the new property. Is this intended or a bug in EF? How do I get around this problem? Should I abandon inheritance altogether?

  Read the article

• Import package problem in GWT

  - by Krt_Malta

  Hi! I'm developing an app using GWT Eclipse plug-in. (I'm also using GWT Designer but I don't think the problem is here). Previously when I wanted to communicate with a web service I created, I produced the "skeleton" classes from the WSDL url using Sun's wsimport tool. Then I would add the classes generated to a class folder in my Eclipse project. All worked well. However this doesn't seem to be working with GWT. I have these: VideoTutorialServiceService service = new VideoTutorialServiceService(); VideoTutorialService port = service.getVideoTutorialServicePort(); and I have VideoTutorialServiceService and VideoTutorialService underlined in red, the error saying videotutorialservice.VideoTutorialServiceService can not be found in source packages. Check the inheritance chain from your module; it may not be inheriting a required module or a module may not be adding its source path entries properly. .... I googled about it but I got confused. I'm a beginnier in GWT. How can I resolve this please? Thanks and regards, Krt_Malta

  Read the article

• Drupal workflow action access integrated with taxonomy access control?

  - by groovehunter

  hi, I am building a DMS for our intranet and use a taxonomy hierarchy because we need access control that way. All company locations manage (upload,edit) their own documents but should be able to access all. This is inherited to the child terms and works fine. Additionally we want simple 3-step workflow (draft,published,archived). So i introduced roles for editor, publisher and docadmin and set permissions for the transitions. Also triggers to effectivly (un)publish documents. But (of course) a user of role publisher can do the transition for ALL documents. But we want publisher for each company location (top taxonomy level, see above). Could this be achieved? Do i have to set it up by myself (i guess "rules" is appropriate to do this) or is there another module helping. role inheritance was a guess, but that is only about roles (naturally). "module grants" i use and checked first option. That way my thoughts are going. I hope you get my idea resp. problem. drupal 6.16 current edit: I reread the docs and found ie. http://drupal.org/node/408018 Revisioning for categorized content. Will reread that.

  Read the article

• testing if constructor in constructor chain

  - by Delan Azabani

  I'm attempting to implement a GTK+ inspired widget toolkit for the web in JavaScript. One of the constructor chains goes gtk.widget => gtk.container => gtk.bin => gtk.window Every gtk.widget has a showAll method, which, if and only if the widget is a gtk.container or derivative (such as gtk.bin or gtk.window), will recursively show the children of that widget. Obviously, if it isn't a gtk.container or derivative, we shouldn't do anything because the widget in question can't contain anything. For reference, here is my inheritance function; it's probably not the best, but it's a start: function inherit(target, parent) { target.prototype = new parent; target.prototype.constructor = target; } I know that I can check for the direct constructor like this: if (this.constructor === gtk.container) ... However, this only tests for direct construction and not, say, if the object is a gtk.bin or gtk.window. How can I test whether gtk.container is somewhere up in the constructor chain?

  Read the article

• Cache Class compilation error using parent-child relationships and cache sql storage

  - by Fred Altman

  I have the global listed below that I'm trying to create a couple of cache classes using sql stoarage for: ^WHEAIPP(1,26,1)=2 ^WHEAIPP(1,26,1,1)="58074^^SMSNARE^58311" 2)="58074^59128^MPHILLIPS^59135" ^WHEAIPP(1,29,1)=2 ^WHEAIPP(1,29,1,1)="58074^^SMSNARE^58311" 2)="58074^59128^MPHILLIPS^59135" ^WHEAIPP(1,93,1)=2 ^WHEAIPP(1,93,1,1)="58884^^SSNARE^58948" 2)="58884^59128^MPHILLIPS^59135" ^WHEAIPP(1,166,1)=2 ^WHEAIPP(1,166,1,1)="58407^^SMSNARE^58420" 2)="58407^59128^MPHILLIPS^59135" ^WHEAIPP(1,324,1)=2 ^WHEAIPP(1,324,1,1)="58884^^SSNARE^58948" 2)="58884^59128^MPHILLIPS^59135" ^WHEAIPP(1,419,1)=3 ^WHEAIPP(1,419,1,1)="59707^^SSNARE^59708" 2)="59707^^MPHILLIPS^59910,58000^^^^" 3)="59707^59981^SSNARE^60117,53241^^^^" The first two subscripts of the global (Hmo and Keen) make a unique entry. The third subscript (Seq) has a property (IppLineCount) which is the number of IppLines in the fourth subscript level (Seq2). I create the class WIppProv below which is the parent class: /// <PRE> /// ============================ /// Generated Class Definition /// Table: WMCA_B_IPP_PROV /// Generated by: FXALTMAN /// Generated on: 05/21/2012 13:46:41 /// Generator: XWESTblClsGenV2 /// ---------------------------- /// </PRE> Class XFXA.MCA.WIppProv Extends (%Persistent, %XML.Adaptor) [ ClassType = persistent, Inheritance = right, ProcedureBlock, StorageStrategy = SQLMapping ] { /// .HMO Property Hmo As %Integer; /// .KEEN Property Keen As %Integer; /// .SEQ Property Seq As %String; Property IppLineCount As %Integer; Index iMaster On (Hmo, Keen, Seq) [ IdKey, Unique ]; Relationship IppLines As XFXA.MCA.WIppProvLine [ Cardinality = many, Inverse = relWIppProv ]; <Storage name="SQLMapping"> <DataLocation>^WHEAIPP</DataLocation> <ExtentSize>1000000</ExtentSize> <SQLMap name="DBMS"> <Data name="IppLineCount"> <Delimiter>"^"</Delimiter> <Node>+0</Node> <Piece>1</Piece> </Data> <Global>^WHEAIPP</Global> <PopulationType>full</PopulationType> <Subscript name="1"> <AccessType>Sub</AccessType> <Expression>{Hmo}</Expression> <LoopInitValue>1</LoopInitValue> </Subscript> <Subscript name="2"> <AccessType>Sub</AccessType> <Expression>{Keen}</Expression> </Subscript> <Subscript name="3"> <AccessType>Sub</AccessType> <LoopInitValue>1</LoopInitValue> <Expression>{Seq}</Expression> </Subscript> <Type>data</Type> </SQLMap> <StreamLocation>^XFXA.MCA.WIppProvS</StreamLocation> <Type>%Library.CacheSQLStorage</Type> </Storage> } This class compiles fine. Next I created the WIppProvLine class listed below and made a parent-child relationship between the two: /// Used to represent a single line of IPP data Class XFXA.MCA.WIppProvLine Extends (%Persistent, %XML.Adaptor) [ ClassType = persistent, Inheritance = right, ProcedureBlock, StorageStrategy = SQLMapping ] { /// .CLM_AMT_ALLOWED node: 0 piece: 6<BR> /// This field should be used in conjunction with the Claim Operator field to /// define a whole claim dollar amount at which a particular claim should be /// flagged with a Pend status. Property ClmAmtAllowed As %String; /// .CLM_LINE_AMT_ALLOWED node: 0 piece: 8<BR> /// This field should be used in conjunction with the Clm Line Operator field to /// define a claim line dollar amount at which a particular claim should be flagged /// with a Pend status. Property ClmLineAmtAllowed As %String; /// .CLM_LINE_OP node: 0 piece: 7<BR> /// A new Table/Column Reference that gives the SIU (Special Investigative Unit) /// the ability to look for claim line dollars above, below, or equal to a set /// amount. Property ClmLineOp As %String; /// .CLM_OP node: 0 piece: 5<BR> /// A new Table/Column Reference that gives the SIU (Special Investigative Unit) /// the ability to look for claim dollars above, below, or equal to a set amount. Property ClmOp As %String; Property EffDt As %Date; Property Hmo As %Integer; /// .IPP_REASON node: 0 piece: 10<BR> /// IPP Reason Code Property IppCode As %Integer; Property Keen As %Integer; /// .LAST_CHG_DT node: 0 piece: 4<BR> /// Last Changed Date Property LastChgDt As %Date; /// .PX_DX_CDE_FLAG node: 0 piece: 9<BR> /// A Flag to indicate whether or not Procedure Codes or Diagnosis Codes are to be /// associated with this SIU Flag Type Entry. If the Flag = Y, then control would /// jump to a new screen where the user can enter the necessary codes. Property PxDxCdeFlag As %String; Property Seq As %String; Property Seq2 As %String; Index iMaster On (Hmo, Keen, Seq, Seq2) [ IdKey, PrimaryKey, Unique ]; /// .TERM_DT node: 0 piece: 2<BR> /// Term Date Property TermDt As %Date; /// .USER_INI node: 0 piece: 3 Property UserIni As %String; Relationship relWIppProv As XFXA.MCA.WIppProv [ Cardinality = one, Inverse = IppLines ]; Index relWIppProvIndex On relWIppProv; //Index NewIndex1 On (RelWIppProv, Seq2) [ IdKey, PrimaryKey, Unique ]; <Storage name="SQLMapping"> <ExtentSize>1000000</ExtentSize> <SQLMap name="DBMS"> <ConditionalWithHostVars></ConditionalWithHostVars> <Data name="ClmAmtAllowed"> <Delimiter>"^"</Delimiter> <Node>+0</Node> <Piece>6</Piece> </Data> <Data name="ClmLineAmtAllowed"> <Delimiter>"^"</Delimiter> <Node>+0</Node> <Piece>8</Piece> </Data> <Data name="ClmLineOp"> <Delimiter>"^"</Delimiter> <Node>+0</Node> <Piece>7</Piece> </Data> <Data name="ClmOp"> <Delimiter>"^"</Delimiter> <Node>+0</Node> <Piece>5</Piece> </Data> <Data name="EffDt"> <Delimiter>"^"</Delimiter> <Node>+0</Node> <Piece>1</Piece> </Data> <Data name="Hmo"> <Delimiter>"^"</Delimiter> <Node>+0</Node> <Piece>11</Piece> </Data> <Data name="IppCode"> <Delimiter>"^"</Delimiter> <Node>+0</Node> <Piece>10</Piece> </Data> <Data name="LastChgDt"> <Delimiter>"^"</Delimiter> <Node>+0</Node> <Piece>4</Piece> </Data> <Data name="PxDxCdeFlag"> <Delimiter>"^"</Delimiter> <Node>+0</Node> <Piece>9</Piece> </Data> <Data name="TermDt"> <Delimiter>"^"</Delimiter> <Node>+0</Node> <Piece>2</Piece> </Data> <Data name="UserIni"> <Delimiter>"^"</Delimiter> <Node>+0</Node> <Piece>3</Piece> </Data> <Global>^WHEAIPP</Global> <Subscript name="1"> <AccessType>Sub</AccessType> <Expression>{Hmo}</Expression> <LoopInitValue>1</LoopInitValue> </Subscript> <Subscript name="2"> <AccessType>Sub</AccessType> <Expression>{Keen}</Expression> <LoopInitValue>1</LoopInitValue> </Subscript> <Subscript name="3"> <AccessType>Sub</AccessType> <Expression>{Seq}</Expression> <LoopInitValue>1</LoopInitValue> </Subscript> <Subscript name="4"> <AccessType>Sub</AccessType> <Expression>{Seq2}</Expression> <LoopInitValue>1</LoopInitValue> </Subscript> <Type>data</Type> </SQLMap> <StreamLocation>^XFXA.MCA.WIppProvLineS</StreamLocation> <Type>%Library.CacheSQLStorage</Type> </Storage> } When I try to compile this one I get the following error: ERROR #5502: Error compiling SQL Table 'XFXA_MCA.WIppProvLine %msg: Table XFXA_MCA.WIppProvLine has the following unmapped (not defined on the data map) fields: relWIppProv' ERROR #5030: An error occurred while compiling class XFXA.MCA.WIppProvLine Detected 1 errors during compilation in 2.745s. What am I doing wrong? Thanks in Advance, Fred

  Read the article

• Beyond core java

  - by Paul

  Coming to the end of the first year of my CS degree, we've done some Java but just the core stuff; manipulating strings and arrays, inheritance, implementing logic etc. I visit this website daily and I see so much stuff that is beyond me; using frameworks; managing databases etc. It makes me feel like I've just learned the syntax of Java, and there is so much more to do with it. My question is though, how do I get there? I don't think I'm advanced enough to join an open source project, which seems to be suggested often (though I'd love to) and I've looked at other similar questions on here (like this one) but even then I don't think that'd work for me.. firstly, could somebody try give me some commonly used frameworks etc and how and what they are used for? Where would be a good place to start? How did you get started in using the things you do? Or perhaps you think I'm going down the wrong route. Should I learn another language, and just wait until the moment occurs where it's clear what I should be doing? I'm only in the first year of my degree, so far we've lightly covered Haskell and Java, and I've done a little HTML and CSS in my free time. I know that next year we cover python, so perhaps I should just wait till then and see if I prefer that? I feel like I also risk learning something in depth and then never using it... I suppose I'm also asking for personal experiences; was there a point where you felt you'd exceeded the basic grasp of a language (does not necessarily have to be Java related) and reach a more "advanced" level? I guess I'll put subjective tag on this, but really I just want to know how to get beyond the basic understanding of a language.

  Read the article

• SO what RDF database do i use for product attribute situation initially i thought about using EAV?

  - by keisimone

  Hi, i have a similar issue as espoused in http://stackoverflow.com/questions/695752/product-table-many-kinds-of-product-each-product-has-many-parameters i am convinced to use RDF now. only because of one of the comments made by Bill Karwin in the answer to the above issue but i already have a database in mysql and the code is in php. 1) So what RDF database should I use? 2) do i combine the approach? meaning i have a class table inheritance in the mysql database and just the weird product attributes in the RDF? I dont think i should move everything to a RDF database since it is only just products and the wide array of possible attributes and value that is giving me the problem. 3) what php resources, articles should i look at that will help me better in the creation of this? 4) more articles or resources that helps me to better understand RDF in the context of the above challenge of building something that will better hold all sorts of products' attributes and values will be greatly appreciated. i tend to work better when i have a conceptual understanding of what is going on. Do bear in mind i am a complete novice to this and my knowledge of programming and database is average at best.

  Read the article

• rails: has_many :through validation?

  - by ramonrails

  Rails 2.1.0 (Cannot upgrade for now due to several constraints) I am trying to achieve this. Any hints? A project has many users through join model A user has many projects through join model Admin class inherits User class. It also has some Admin specific stuff. Admin like inheritance for Supervisor and Operator Project has one Admin, One supervisor and many operators. Now I want to 1. submit data for project, admin, supervisor and operator in a single project form 2. validate all and show errors on the project form. Project has_many :projects_users ; has_many :users, :through => :projects_users User has_many :projects_users ; has_many :projects, :through => :projects_users ProjectsUser = :id integer, :user_id :integer, :project_id :integer, :user_type :string ProjectUser belongs_to :project, belongs_to :user Admin < User # User has 'type:string' column for STI Supervisor < User Operator < User Is the approach correct? Any and all suggestions are welcome.

  Read the article

• Pronunciation of programming structures (particularly in c#)

  - by Andrzej Nosal

  As a non-English speaking person I often have problems pronouncing certain programming structures and abbreviations. I've been watching some video tutorials and listening to podcasts as well, though I couldn't catch them all. My question is what is the common or correct pronunciation of the following code snippets? Generics, like IEnumerable<int> or in a method void Swap<T>(T lhs, T rhs) Collections indexing and indexer access e.g. garage[i], rectangular arrays myArray[2,1] or jagged[1][2][3] Lambda operator =>, e.g. in a where extension method .Where(animal => animal.Color == Color.Brown) or in an anonymous method () => { return false;} Inheritance class Derived : Base (extends?) class SomeClass : IDisposable (implements?) Arithemtic operators += -= *= /= %= ! Are += and -= pronounced the same for events? Collections initializers new int[] { 4, 5, 8, 9, 12, 13, 16, 17 }; Casting MyEnum foo = (MyEnum)(int)yourFloat; (as?) Nullables DateTime? dt = new DateTime?(); I tagged the question with C# as some of them are specific to C# only.

  Read the article

• Django - how to write users and profiles handling in best way?

  - by SpankMe

  Hey, I am writing simple site that requires users and profiles to be handled. The first initial thought is to use django's build in user handling, but then the user model is too narrow and does not contain fields that I need. The documentation mentions user profiles, but user profiles section has been removed from djangobook covering django 1.0 (ideally, the solution should work with django 1.2), and the Internet is full of different solutions, not making the choice easier (like user model inheritance, user profiles and django signals, and so on). I would like to know, how to write this in good, modern, fast and secure way. Should I try to extend django builtin user model, or maybe should I create my own user model wide enough to keep all the information I need? Below you may find some specifications and expectations from the working solution: users should be able to register and authenticate every user should have profile (or model with all required fields) users dont need django builtin admin panel, but they need to edit their profiles/models via simple web form Please, let me know how do you solve those issues in your applications, and what is the best current way to handle users with django. Any links to articles/blogs or code examples are highly appreciated!

  Read the article

• Discriminator based on joined property

  - by Andrew

  Suppose I have this relationship: abstract class Base { int Id; int JoinedId; ... } class Joined { int Id; int Discriminator; ... } class Sub1 : Base { ... } class Sub2 : Base { ... } for the following tables: table Base ( Id int, JoinedId int, ... ) table Joined ( Id int, Discriminator int, ... ) I would like to set up a table-per-hierarchy inheritance mapping for the Base, Sub1, Sub2 relationships, but using the Disciminator property from the Joined class as the discriminator. Here's the general idea for the mapping file: <class name="Base" table="Base"> <id name="Id"><generator class="identity"/></id> <discriminator /> <!-- ??? or <join> or <many-to-one>? --> <subclass name="Sub1" discriminator-value="1">...</subclass> <subclass name="Sub2" discriminator-value="2">...</subclass> </class> Is there any way of accomplishing something like this with the <discriminator>, <join>, or <many-to-one>? NHiberante seems to assume the discriminator is a column on the given table (which makes sense to me.. I know this is unorthodox). Thanks.

  Read the article

• Strategy Pattern with Type Reflection affecting Performances ?

  - by Aurélien Ribon

  Hello ! I am building graphs. A graph consists of nodes linked each other with links (indeed my dear). In order to assign a given behavior to each node, I implemented the strategy pattern. class Node { public BaseNodeBehavior Behavior {get; set;} } As a result, in many parts of the application, I am extensively using type reflection to know which behavior a node is. if (node.Behavior is NodeDataOutputBehavior) workOnOutputNode(node) .... My graph can get thousands of nodes. Is type reflection greatly affecting performances ? Should I use something else than the strategy pattern ? I'm using strategy because I need behavior inheritance. For example, basically, a behavior can be Data or Operator, a Data behavior can IO, Const or Intermediate and finally an IO behavior can be Input or Output. So if I use an enumeration, I wont be able to test for a node behavior to be of data kind, I will need to test it to be [Input, Output, Const or Intermediate]. And if later I want to add another behavior of Data kind, I'm screwed, every data-testing method will need to be changed.

  Read the article

• How to develop modular web UIs with Django?

  - by nh2

  When doing larger sites in "big business", you most probalbly work in a team with several developers. Let's say dev A makes a form to insert new user data, B creates a user list, C makes some privilege administration and D does crazy statistic graphs work with image generation and so on. Each dev begins to develop his own component, creates a view and a template and tests that independently, until each component works. Now, the client wants to have all those components on one bit HTML page. How to achieve this? How to assemble different views/templates in a form of composition so that they remain modular and can be developed and tested independently? It seems inheritance is not the way to go because all of those UI components are equal and there is no hierarchy. The idea of the assembling template is something like <html> <head> // include the css for the components and their assembly </head> <body> // include user data form here <some containers, images, and so on> // show user list // show privilege administration in this part // and finally, the nice statistic graphs // perhaps, we want to display some other components here in future </body> </html> I have not found an answer on the net yet. Most people come up with one big template which just implements all of the UI functionality, removing all modularity. Each component shall have its own template and view dealing only with that component developed by one person each, and they then shall be sticked together just like bricks. I would highly appreciate any hints!

  Read the article

• Is this a good job description? What title would you give this position?

  - by Zack Peterson

  Department: Information Technology Reports To: Chief Information Officer Purpose: Company's ________________ is specifically engaged in the development of World Wide Web applications and distributed network applications. This person is concerned with all facets of the software development process and specializes in software product management. He or she contributes to projects in an application architect role and also performs individual programming tasks. Essential Duties & Responsibilities: This person is involved in all aspects of the software development process such as: Participation in software product definitions, including requirements analysis and specification Development and refinement of simulations or prototypes to confirm requirements Feasibility and cost-benefit analysis, including the choice of architecture and framework Application and database design Implementation (e.g. installation, configuration, customization, integration, data migration) Authoring of documentation needed by users and partners Testing, including defining/supporting acceptance testing and gathering feedback from pre-release testers Participation in software release and post-release activities, including support for product launch evangelism (e.g. developing demonstrations and/or samples) and subsequent product build/release cycles Maintenance Qualifications: Bachelor's degree in computer science or software engineering Several years of professional programming experience Proficiency in the general technology of the World Wide Web: Hypertext Transfer Protocol (HTTP) Hypertext Markup Language (HTML) JavaScript Cascading Style Sheets (CSS) Proficiency in the following principles, practices, and techniques: Accessibility Interoperability Usability Security (especially prevention of SQL injection and cross-site scripting (XSS) attacks) Object-oriented programming (e.g. encapsulation, inheritance, modularity, polymorphism, etc.) Relational database design (e.g. normalization, orthogonality) Search engine optimization (SEO) Asynchronous JavaScript and XML (AJAX) Proficiency in the following specific technologies utilized by Company: C# or Visual Basic .NET ADO.NET (including ADO.NET Entity Framework) ASP.NET (including ASP.NET MVC Framework) Windows Presentation Foundation (WPF) Language Integrated Query (LINQ) Extensible Application Markup Language (XAML) jQuery Transact-SQL (T-SQL) Microsoft Visual Studio Microsoft Internet Information Services (IIS) Microsoft SQL Server Adobe Photoshop

  Read the article

• Correct way of setting a custom FileInfo class to an Iterator

  - by Gordon

  I am trying to set a custom class to an Iterator through the setInfoClass method: Use this method to set a custom class which will be used when getFileInfo and getPathInfo are called. The class name passed to this method must be derived from SplFileInfo. My class is like this (simplified example): class MyFileInfo extends SplFileInfo { public $props = array( 'foo' => '1', 'bar' => '2' ); } The iterator code is this: $rit = new RecursiveIteratorIterator( new RecursiveDirectoryIterator('/some/file/path/'), RecursiveIteratorIterator::SELF_FIRST); Since RecursiveDirectoryIterator is by inheritance through DirectoryIterator also an SplFileInfo object, it provides the setInfoClass method (it's not listed in the manual, but reflection shows it's there). Thus I can do: $rit->getInnerIterator()->setInfoClass('MyFileInfo'); All good up to here, but when iterating over the directory with foreach($rit as $file) { var_dump( $file ); } I get the following weird result object(MyFileInfo)#4 (3) { ["props"]=>UNKNOWN:0 ["pathName":"SplFileInfo":private]=>string(49) "/some/file/path/someFile.txt" ["fileName":"SplFileInfo":private]=>string(25) "someFile.txt" } So while MyFileInfo is picked up, I cannot access it's properties. If I add custom methods, I can invoke them fine, but any properties are UNKNOWN. If I don't set the info class to the iterator, but to the SplFileInfo object (like shown in the example in the manual), it will give the same UNKNOWN result: foreach($rit as $file) { // $file is a SplFileInfo instance $file->setInfoClass('MyFileInfo'); var_dump( $file->getFileInfo() ); } However, it will work when I do foreach($rit as $file) { $file = new MyFileInfo($file); var_dump( $file ); } Unfortunately, the code I a want to use this in is somewhat more complicated and stacks some more iterators. Creating the MyFileInfo class like this is not an option. So, does anyone know how to get this working or why PHP behaves this weird? Thanks.

  Read the article

• Object Oriented Programming in AS3

  - by Jordan

  I'm building a game in as3 that has balls moving and bouncing off the walls. When the user clicks an explosion appears and any ball that hits that explosion explodes too. Any ball that then hits that explosion explodes and so on. My question is what would be the best class structure for the balls. I have a level system to control levels and such and I've already come up with working ways to code the balls. Here's what I've done. My first attempt was to create a class for Movement, Bounce, Explosion and finally Orb. These all extended each other in the order I just named them. I got it working but having Bounce extend Movement and Explosion extend Bounce, it just doesn't seem very object oriented because what if I wanted to add a box class that didn't move, but did explode? I would need a separate class for that explosion. My second attempt was to create Movement, Bounce and Explosion without extending anything. Instead I passed in a reference to the Orb class to each. Then the class stores that reference and does what it needs to do based on events that are dispatched by the Orb such as update, which was broadcast from Orb every enter frame. This would drive the movement and bounce and also the explosion when the time came. This attempt worked as well but it just doesn't seem right. I've also thought about using Interfaces but because they are more of an outline for classes, I feel like code reuse goes out the window as each class would need its own code for a specific task even if that task is exactly the same. I feel as if I'm searching for some form of multiple inheritance for classes that as3 does not support. Can someone explain to me a better way of doing what I'm attempting to do? Am I being to "Object Oriented" by having classed for Movement, Bounce, Explosion and Orb? Are Interfaces the way to go? Any feedback is appreciated!

  Read the article

• MySQL multidimensional arrays...

  - by jay

  What is the best way to store data that is dynamic in nature using MySQL? Let's say I have a table in which one item is "dynamic". For some entries I need to store one value, but for others it could be one hundred values. For example let's say I have the following simple table: CREATE TABLE manager ( name char(50), worker_1_name(50), worker_2_name(50), ... worker_N_name(50) ); Clearly, this is not an ideal way to set up a database. Because I have to accommodate the largest group that a manager could potentially have, I am wasting a lot of space in the database. What I would prefer is to have a table that I can use as a member of another table (like I would do in C++ through inheritance) that can be used by the "manager" table to handle the variable number of employees. It might look something like this. CREATE TABLE manager ( name char(50), underlings WORKERS ); CREATE TABLE WORKERS ( name char(50), ); I would like to be able to add a variable number of workers to each manager. Is this possible or am I constrained to enumerating all the possible number of employees even though I will use the full complement only rarely?

  Read the article

• Am I abusing Policies?

  - by pmr

  I find myself using policies a lot in my code and usually I'm very happy with that. But from time to time I find myself confronted with using that pattern in situations where the Policies are selected and runtime and I have developed habbits to work around such situations. Usually I start with something like that: class DrawArrays { protected: void sendDraw() const; }; class DrawElements { protected: void sendDraw() const; }; template<class Policy> class Vertices : public Policy { using Policy::sendDraw(); public: void render() const; }; When the policy is picked at runtime I have different choices of working around the situation. Different code paths: if(drawElements) { Vertices<DrawElements> vertices; } else { Vertices<DrawArrays> vertices; } Inheritance and virtual calls: class PureVertices { public: void render()=0; }; template<class Policy> class Vertices : public PureVertices, public Policy { //.. }; Both solutions feel wrong to me. The first creates an umaintainable mess and the second introduces the overhead of virtual calls that I tried to avoid by using policies in the first place. Am I missing the proper solutions or do I use the wrong pattern to solve the problem?

  Read the article

< Previous Page | 52 53 54 55 56 57 58 59 60 61 62 63  | Next Page >