Search Results

Search found 31554 results on 1263 pages for 'object identity'.

Page 122/1263 | < Previous Page | 118 119 120 121 122 123 124 125 126 127 128 129  | Next Page >

• JavaScript way to tell if an object is an Array

  - by damienmac

  What's the 'right' way to tell if an object is an Array? function isArray(o) { ??? }

  Read the article

• Which is the good way to update object in EF6

  - by TrieuH

  I have searched and find 2 way to update object in EF var attachedEntity = _context.EntityClasses.Local.First(t => t.Id == entity.Id); //We have it in the context, need to update. if (attachedEntity != null) { var attachedEntry = _context.Entry(attachedEntity); attachedEntry.CurrentValues.SetValues(entity); } else { ////If it's not found locally, we can attach it by setting state to modified. ////This would result in a SQL update statement for all fields ////when SaveChanges is called. var entry = _context.Entry(entity); entry.State = EntityState.Modified; } _context.SaveChanges(); And other way is seem more easy var entity = _context.EntityClasses.FirstOrDefault(t => t.Id == entity.Id); _context.Entry(entity ).EntityState.Modified _context.SaveChanges(); What is best way to update object? NOTE: the performence is importance with me

  Read the article

• Java Basics: create class object

  - by user1767853

  In C++: class Rectangle { int x, y; public: void set_values (int,int); int area () {return (x*y);} }; int main () { Rectangle rect; rect.set_values (3,4); } In Java: class Rectangle { int x, y; void set_values (int x,int y); int area () {return (x*y);} } public static void main(String[] args) { Rectangle rect=new Rectangle(3,4); } In C++ compiler will create rect object & reserve memory 4 bytes. I want to know How Java is creating object?

  Read the article

• how to declare object variable name in loop

  - by user3717895

  public class Node{ Node p,l,r; int height; String s; { /** class body**/ } } String[] S=new String[5000]; int i=0; while (i<5000){ Node x=new Node(); x=S[i]; } I want to make 5000 Node object. above code assign same variable name x every time but i want different variable name . then how to declare 5000 class variable name without declaring it manually. is there something by which i can create 5000 Node class object with ease.

  Read the article

• Lessons From OpenId, Cardspace and Facebook Connect

  - by mark.wilcox

  (c) denise carbonell I think Johannes Ernst summarized pretty well what happened in a broad sense in regards to OpenId, Cardspace and Facebook Connect. However, I'm more interested in the lessons we can take away from this. First  - "Apple Lesson" - If user-centric identity is going to happen it's going to require not only technology but also a strong marketing campaign. I'm calling this the "Apple Lesson" because it's very similar to how Apple iPad saw success vs the tablet market. The iPad is not only a very good technology product but it was backed by a very good marketing plan. I know most people do not want to think about marketing here - but the fact is that nobody could really articulate why user-centric identity mattered in a way that the average person cared about. Second - "Facebook Lesson" - Facebook Connect solves a number of interesting problems that is easy for both consumer and service providers. For a consumer it's simple to log-in without any redirects. And while Facebook isn't perfect on privacy - no other major consumer-focused service on the Internet provides as much control about sharing identity information. From a developer perspective it is very easy to implement the SSO and fetch other identity information (if the user has given permission). This could only happen because a major company just decided to make a singular focus to make it happen. Third - "Developers Lesson" -  Facebook Social Graph API is by far the simplest API for accessing identity information which also is another reason why you're seeing such rapid growth in Facebook enabled Websites. By using a combination of URL and Javascript - the power a single HTML page now gives a developer writing Web applications is simply amazing. For example It doesn't get much simpler than this "http://api.facebook.com/mewilcox" for accessing identity. And while I can't yet share too much publicly about the specifics - the social graph API had a profound impact on me in designing our next generation APIs.  Posted via email from Virtual Identity Dialogue

  Read the article

• Banshee crashes consistently - is there a fix?

  - by user36334

  Since updating to ubuntu 11.10 I've had trouble with banshee. In particular when I run it I find that it crashes within an hour without fail. I get the following Unhandled Exception: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object at Mono.Zeroconf.Providers.AvahiDBus.BrowseService.DisposeResolver () [0x00000] in <filename unknown>:0 at Mono.Zeroconf.Providers.AvahiDBus.BrowseService.Dispose () [0x00000] in <filename unknown>:0 at Mono.Zeroconf.Providers.AvahiDBus.ServiceBrowser.OnItemRemove (Int32 interface, Protocol protocol, System.String name, System.String type, System.String domain, LookupResultFlags flags) [0x00000] in <filename unknown>:0 at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,object,object[],System.Exception&) at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0 --- End of inner exception stack trace --- at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0 at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] in <filename unknown>:0 at System.Delegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0 at System.MulticastDelegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0 at System.Delegate.DynamicInvoke (System.Object[] args) [0x00000] in <filename unknown>:0 at NDesk.DBus.Connection.HandleSignal (NDesk.DBus.Message msg) [0x00000] in <filename unknown>:0 at NDesk.DBus.Connection.DispatchSignals () [0x00000] in <filename unknown>:0 at NDesk.DBus.Connection.Iterate () [0x00000] in <filename unknown>:0 at Mono.Zeroconf.Providers.AvahiDBus.DBusManager.IterateThread (System.Object o) [0x00000] in <filename unknown>:0 Does anyone else also have this problem?

  Read the article

• New Online Learning Library (OLL) content

  - by Irina

  Looking to brush up on OAM or OVD skills? Want some help with OIM? Well, have you checked our Online Learning Library (OLL) recently? OLL is a great way to pickup new skills in short blocks of time, and there is an enormous selection, on a diverse set of products. Every month these trainings get hundreds or thousands of hits. It would be worth your while to spend some time just poking around the nooks and crannies for items that interest you.A smattering of new OBEs and other content have recently become available, and if you haven't already, you might want to check them out: Identity Management: Business Scenarios Business and IT – Collaborative Access Review Sign Off and Closed Loop Identity Certification Oracle Identity Governance: End to End integration From Oracle Identity Manager to a Target Webservice Oracle Identity Manager: Configuring SOA Composite Oracle Identity Manager: Web Services Connector - Overview How to do a basic Oracle Virtual Directory (OVD) Setup? How to setup a simple Oracle Virtual Directory (OVD) Join? Installing Oracle Access Manager: Identity Server and WebPass  Also new is an Oracle University 5-day class you might want to investigate: Oracle Access Manager R2: Administration Essentials An OAM Advanced Administration class is in the works and should be available late summer or fall, so keep your calendar clear! Be sure to let us know in the Comments if there is a training you would find useful. Happy Trails :)

  Read the article

• The dynamic Type in C# Simplifies COM Member Access from Visual FoxPro

  - by Rick Strahl

  I’ve written quite a bit about Visual FoxPro interoperating with .NET in the past both for ASP.NET interacting with Visual FoxPro COM objects as well as Visual FoxPro calling into .NET code via COM Interop. COM Interop with Visual FoxPro has a number of problems but one of them at least got a lot easier with the introduction of dynamic type support in .NET. One of the biggest problems with COM interop has been that it’s been really difficult to pass dynamic objects from FoxPro to .NET and get them properly typed. The only way that any strong typing can occur in .NET for FoxPro components is via COM type library exports of Visual FoxPro components. Due to limitations in Visual FoxPro’s type library support as well as the dynamic nature of the Visual FoxPro language where few things are or can be described in the form of a COM type library, a lot of useful interaction between FoxPro and .NET required the use of messy Reflection code in .NET. Reflection is .NET’s base interface to runtime type discovery and dynamic execution of code without requiring strong typing. In FoxPro terms it’s similar to EVALUATE() functionality albeit with a much more complex API and corresponiding syntax. The Reflection APIs are fairly powerful, but they are rather awkward to use and require a lot of code. Even with the creation of wrapper utility classes for common EVAL() style Reflection functionality dynamically access COM objects passed to .NET often is pretty tedious and ugly. Let’s look at a simple example. In the following code I use some FoxPro code to dynamically create an object in code and then pass this object to .NET. An alternative to this might also be to create a new object on the fly by using SCATTER NAME on a database record. How the object is created is inconsequential, other than the fact that it’s not defined as a COM object – it’s a pure FoxPro object that is passed to .NET. Here’s the code: *** Create .NET COM InstanceloNet = CREATEOBJECT('DotNetCom.DotNetComPublisher') *** Create a Customer Object Instance (factory method) loCustomer = GetCustomer() loCustomer.Name = "Rick Strahl" loCustomer.Company = "West Wind Technologies" loCustomer.creditLimit = 9999999999.99 loCustomer.Address.StreetAddress = "32 Kaiea Place" loCustomer.Address.Phone = "808 579-8342" loCustomer.Address.Email = "[email protected]" *** Pass Fox Object and echo back values ? loNet.PassRecordObject(loObject) RETURN FUNCTION GetCustomer LOCAL loCustomer, loAddress loCustomer = CREATEOBJECT("EMPTY") ADDPROPERTY(loCustomer,"Name","") ADDPROPERTY(loCustomer,"Company","") ADDPROPERTY(loCUstomer,"CreditLimit",0.00) ADDPROPERTY(loCustomer,"Entered",DATETIME()) loAddress = CREATEOBJECT("Empty") ADDPROPERTY(loAddress,"StreetAddress","") ADDPROPERTY(loAddress,"Phone","") ADDPROPERTY(loAddress,"Email","") ADDPROPERTY(loCustomer,"Address",loAddress) RETURN loCustomer ENDFUNC Now prior to .NET 4.0 you’d have to access this object passed to .NET via Reflection and the method code to do this would looks something like this in the .NET component: public string PassRecordObject(object FoxObject) { // *** using raw Reflection string Company = (string) FoxObject.GetType().InvokeMember( "Company", BindingFlags.GetProperty,null, FoxObject,null); // using the easier ComUtils wrappers string Name = (string) ComUtils.GetProperty(FoxObject,"Name"); // Getting Address object – then getting child properties object Address = ComUtils.GetProperty(FoxObject,"Address");    string Street = (string) ComUtils.GetProperty(FoxObject,"StreetAddress"); // using ComUtils 'Ex' functions you can use . Syntax     string StreetAddress = (string) ComUtils.GetPropertyEx(FoxObject,"AddressStreetAddress"); return Name + Environment.NewLine + Company + Environment.NewLine + StreetAddress + Environment.NewLine + " FOX"; } Note that the FoxObject is passed in as type object which has no specific type. Since the object doesn’t exist in .NET as a type signature the object is passed without any specific type information as plain non-descript object. To retrieve a property the Reflection APIs like Type.InvokeMember or Type.GetProperty().GetValue() etc. need to be used. I made this code a little simpler by using the Reflection Wrappers I mentioned earlier but even with those ComUtils calls the code is pretty ugly requiring passing the objects for each call and casting each element. Using .NET 4.0 Dynamic Typing makes this Code a lot cleaner Enter .NET 4.0 and the dynamic type. Replacing the input parameter to the .NET method from type object to dynamic makes the code to access the FoxPro component inside of .NET much more natural: public string PassRecordObjectDynamic(dynamic FoxObject) { // *** using raw Reflection string Company = FoxObject.Company; // *** using the easier ComUtils class string Name = FoxObject.Name; // *** using ComUtils 'ex' functions to use . Syntax string Address = FoxObject.Address.StreetAddress; return Name + Environment.NewLine + Company + Environment.NewLine + Address + Environment.NewLine + " FOX"; } As you can see the parameter is of type dynamic which as the name implies performs Reflection lookups and evaluation on the fly so all the Reflection code in the last example goes away. The code can use regular object ‘.’ syntax to reference each of the members of the object. You can access properties and call methods this way using natural object language. Also note that all the type casts that were required in the Reflection code go away – dynamic types like var can infer the type to cast to based on the target assignment. As long as the type can be inferred by the compiler at compile time (ie. the left side of the expression is strongly typed) no explicit casts are required. Note that although you get to use plain object syntax in the code above you don’t get Intellisense in Visual Studio because the type is dynamic and thus has no hard type definition in .NET . The above example calls a .NET Component from VFP, but it also works the other way around. Another frequent scenario is an .NET code calling into a FoxPro COM object that returns a dynamic result. Assume you have a FoxPro COM object returns a FoxPro Cursor Record as an object: DEFINE CLASS FoxData AS SESSION OlePublic cAppStartPath = "" FUNCTION INIT THIS.cAppStartPath = ADDBS( JustPath(Application.ServerName) ) SET PATH TO ( THIS.cAppStartpath ) ENDFUNC FUNCTION GetRecord(lnPk) LOCAL loCustomer SELECT * FROM tt_Cust WHERE pk = lnPk ; INTO CURSOR TCustomer IF _TALLY < 1 RETURN NULL ENDIF SCATTER NAME loCustomer MEMO RETURN loCustomer ENDFUNC ENDDEFINE If you call this from a .NET application you can now retrieve this data via COM Interop and cast the result as dynamic to simplify the data access of the dynamic FoxPro type that was created on the fly: int pk = 0; int.TryParse(Request.QueryString["id"],out pk); // Create Fox COM Object with Com Callable Wrapper FoxData foxData = new FoxData(); dynamic foxRecord = foxData.GetRecord(pk); string company = foxRecord.Company; DateTime entered = foxRecord.Entered; This code looks simple and natural as it should be – heck you could write code like this in days long gone by in scripting languages like ASP classic for example. Compared to the Reflection code that previously was necessary to run similar code this is much easier to write, understand and maintain. For COM interop and Visual FoxPro operation dynamic type support in .NET 4.0 is a huge improvement and certainly makes it much easier to deal with FoxPro code that calls into .NET. Regardless of whether you’re using COM for calling Visual FoxPro objects from .NET (ASP.NET calling a COM component and getting a dynamic result returned) or whether FoxPro code is calling into a .NET COM component from a FoxPro desktop application. At one point or another FoxPro likely ends up passing complex dynamic data to .NET and for this the dynamic typing makes coding much cleaner and more readable without having to create custom Reflection wrappers. As a bonus the dynamic runtime that underlies the dynamic type is fairly efficient in terms of making Reflection calls especially if members are repeatedly accessed. © Rick Strahl, West Wind Technologies, 2005-2010Posted in COM  FoxPro  .NET  CSharp  

  Read the article

• relational data from xml

  - by Beta033

  Our problem is this, we have a relational database to store objects in tables. As any relational database could, several of these tables have multiple foreign keys pointing to other tables (all pretty normal stuff) We've been trying to identify a solution to allow export of this relational data, ideally, only 1 of the objects in the model, to some sort of file (xml, text, ??). So it wouldn't be simple enough to just export 1 table as data stored in other tables would contribute to the complete model of the object. Something like the following picture: Toward this, i've written a routine to export the structure by following the foreign key paths which exports something similar to the following. <Tables> <TableA PK="1", val1, val2, val3> <TableC PK="1", FK_A="1", Val1, val2, val3> <TableC PK="2", FK_A="1", val1, val2, val3> <TableB PK="1", FK_A="1", FK_C="1", val1, val2, val3> <TableB PK="2", FK_A="1", FK_C="2", val1, val2, val3> <TableD PK="1", FK_B="1", FK_C="1", val1> <TableD PK="2", FK_B="2", FK_C="1", val1> </Tables> However, given this structure, it cannot be placed into a heirarchial format (ie D2 is a child of C1 and B2; and B2 is a child of C2) Which in turn, makes my life very difficult when trying to identify a methodology to reimport (and reKey) these objects. Has anybody done anything like this? how do you do it? are there tools or documentation on how this is best accomplished? Thanks for your help.

  Read the article

• Classes, methods, and polymorphism in Python

  - by Morlock

  I made a module prototype for building complex timer schedules in python. The classe prototypes permit to have Timer objects, each with their waiting times, Repeat objects that group Timer and other Repeat objects, and a Schedule class, just for holding a whole construction or Timers and Repeat instances. The construction can be as complex as needed and needs to be flexible. Each of these three classes has a .run() method, permitting to go through the whole schedule. Whatever the Class, the .run() method either runs a timer, a repeat group for a certain number of iterations, or a schedule. Is this polymorphism-oriented approach sound or silly? What are other appropriate approaches I should consider to build such a versatile utility that permits to put all building blocks together in as complex a way as desired with simplicity? Thanks! Here is the module code: ##################### ## Importing modules from time import time, sleep ##################### ## Class definitions class Timer: """ Timer object with duration. """ def __init__(self, duration): self.duration = duration def run(self): print "Waiting for %i seconds" % self.duration wait(self.duration) chime() class Repeat: """ Repeat grouped objects for a certain number of repetitions. """ def __init__(self, objects=[], rep=1): self.rep = rep self.objects = objects def run(self): print "Repeating group for %i times" % self.rep for i in xrange(self.rep): for group in self.objects: group.run() class Schedule: """ Groups of timers and repetitions. Maybe redundant with class Repeat. """ def __init__(self, schedule=[]): self.schedule = schedule def run(self): for group in self.schedule: group.run() ######################## ## Function definitions def wait(duration): """ Wait a certain number of seconds. """ time_end = time() + float(duration) #uncoment for minutes# * 60 time_diff = time_end - time() while time_diff > 0: sleep(1) time_diff = time_end - time() def chime(): print "Ding!"

  Read the article

• AntFarm anti-pattern -- strategies to avoid, antidotes to help heal from

  - by alchemical

  I'm working on a 10 page web site with a database back-end. There are 500+ objects in use, trying to implement the MVP pattern in ASP.Net. I'm tracing the code-execution from a single-page, my finger has been on F-11 in Visual Studio for about 40 minutes, there seems to be no end, possibly 1000+ method calls for one web page! If it was just 50 objects that would be one thing, however, code execution snakes through all these objects just like millions of ants frantically woring in their giant dirt mound house, riddled with object tunnels. Hence, a new anti-pattern is born : AntFarm. AntFarm is also known as "OO-Madnes", "OO-Fever", OO-ADD, or simply design-pattern junkie. This is not the first time I've seen this, nor my associates at other companies. It seems that this style is being actively propogated, or in any case is a misunderstanding of the numerous OO/DP gospels going around... I'd like to introduce an anti-pattern to the anti-pattern: GST or "Get Stuff Done" AKA "Get Sh** done" AKA GRD (GetRDone). This pattern focused on just what it says, getting stuff done, in a simple way. I may try to outline it more in a later post, or please share your ideas on this antidote pattern. Anyway, I'm in the midst of a great example of AntFarm anti-pattern as I write (as a bonus, there is no documentation or comments). Please share you thoughts on how this anti-pattern has become so prevelant, how we can avoid it, and how can one undo or deal with this pattern in a live system one must work with!

  Read the article

• Run unittest in a Class

  - by chrissygormley

  Hello, I have a test suite to perform smoke tests. I have all my script stored in various classes but when I try and run the test suite I can't seem to get it working if it is in a class. The code is below: (a class to call the tests) from alltests import SmokeTests class CallTests(SmokeTests): def integration(self): self.suite() if __name__ == '__main__': run = CallTests() run.integration() And the test suite: class SmokeTests(): def suite(self): #Function stores all the modules to be tested modules_to_test = ('external_sanity', 'internal_sanity') alltests = unittest.TestSuite() for module in map(__import__, modules_to_test): alltests.addTest(unittest.findTestCases(module)) return alltests if __name__ == '__main__': unittest.main(defaultTest='suite') So I can see how to call a normal function defined but I'm finding it difficult calling in the suite. In one of the tests the suite is set up like so: class InternalSanityTestSuite(unittest.TestSuite): # Tests to be tested by test suite def makeInternalSanityTestSuite(): suite = unittest.TestSuite() suite.addTest(TestInternalSanity("BasicInternalSanity")) suite.addTest(TestInternalSanity("VerifyInternalSanityTestFail")) return suite def suite(): return unittest.makeSuite(TestInternalSanity) If I have def suite() inside the class SmokeTests the script executes but the tests don't run but if I remove the class the tests run. I run this as a script and call in variables into the tests. I do not want to have to run the tests by os.system('python tests.py'). I was hoping to call the tests through the class I have like any other function. This need's to be called from a class as the script that I'm calling it from is Object Oriented. If anyone can get the code to be run using Call Tests I would appreciate it alot. Thanks for any help in advance.

  Read the article

• Call bindings for DependencyObject when DependencyProperites are changed

  - by melculetz

  Is there a way to notify a DependencyObject's bindinigs when the inner DependencyProperties have changed? For example, I have this class: public class BackgroundDef : DependencyObject { public static readonly DependencyProperty Color1Property = DependencyProperty.Register("Color1", typeof(Color), typeof(Background), new UIPropertyMetadata(Colors.White)); public static readonly DependencyProperty UseBothColorsProperty = DependencyProperty.Register("UseBothColors", typeof(bool), typeof(Background), new UIPropertyMetadata(false)); public static readonly DependencyProperty Color2Property = DependencyProperty.Register("Color2", typeof(Color), typeof(Background), new UIPropertyMetadata(Colors.White)); public Color Color1 { set { SetValue(Color1Property, value); } get { return (Color)GetValue(Color1Property); } } public bool UseBothColors { set { SetValue(UseBothColorsProperty, value); } get { return (bool)GetValue(UseBothColorsProperty); } } public Color Color2 { set { SetValue(Color2Property, value); } get { return (Color)GetValue(Color2Property); } } } For which I have 3 separate two-way bindings that set the values for Color1, Color2 and UseBothColors. But I also have a binding for a BackgroundDef instance, which should create a Brush and draw the background of a button (either a single color, or two gradient colors). My problem is that the two-way bindings for the DependencyProperties update the properties, but the binding for the class instance is not called, as apparently the entire object does not change. Any idea how I could call the bindings for the DependencyObject when the DependencyProperties are changed?

  Read the article

• Should business objects be able to create their own DTOs?

  - by Sam

  Suppose I have the following class: class Camera { public Camera( double exposure, double brightness, double contrast, RegionOfInterest regionOfInterest) { this.exposure = exposure; this.brightness = brightness; this.contrast = contrast; this.regionOfInterest = regionOfInterest; } public void ConfigureAcquisitionFifo(IAcquisitionFifo acquisitionFifo) { // do stuff to the acquisition FIFO } readonly double exposure; readonly double brightness; readonly double contrast; readonly RegionOfInterest regionOfInterest; } ... and a DTO to transport the camera info across a service boundary (WCF), say, for viewing in a WinForms/WPF/Web app: using System.Runtime.Serialization; [DataContract] public class CameraData { [DataMember] public double Exposure { get; set; } [DataMember] public double Brightness { get; set; } [DataMember] public double Contrast { get; set; } [DataMember] public RegionOfInterestData RegionOfInterest { get; set; } } Now I can add a method to Camera to expose its data: class Camera { // blah blah public CameraData ToData() { var regionOfInterestData = regionOfInterest.ToData(); return new CameraData() { Exposure = exposure, Brightness = brightness, Contrast = contrast, RegionOfInterestData = regionOfInterestData }; } } or, I can create a method that requires a special IReporter to be passed in for the Camera to expose its data to. This removes the dependency on the Contracts layer (Camera no longer has to know about CameraData): class Camera { // beep beep I'm a jeep public void ExposeToReporter(IReporter reporter) { reporter.GetCameraInfo(exposure, brightness, contrast, regionOfInterest); } } So which should I do? I prefer the second, but it requires the IReporter to have a CameraData field (which gets changed by GetCameraInfo()), which feels weird. Also, if there is any even better solution, please share with me! I'm still an object-oriented newb.

  Read the article

• Aren't Information Expert / Tell Don't Ask at odds with Single Responsibility Principle?

  - by moffdub

  It is probably just me, which is why I'm asking the question. Information Expert, Tell Don't Ask, and SRP are often mentioned together as best practices. But I think they are at odds. Here is what I'm talking about: Code that favors SRP but violates Tell Don't Ask, Info Expert: Customer bob = ...; // TransferObjectFactory has to use Customer's accessors to do its work, // violates Tell Don't Ask CustomerDTO dto = TransferObjectFactory.createFrom(bob); Code that favors Tell Don't Ask / Info Expert but violates SRP: Customer bob = ...; // Now Customer is doing more than just representing the domain concept of Customer, // violates SRP CustomerDTO dto = bob.toDTO(); If they are indeed at odds, that's a vindication of my OCD. Otherwise, please fill me in on how these practices can co-exist peacefully. Thank you. Edit: someone wants a definition of the terms - Information Expert: objects that have the data needed for the operation should host the operation Tell Don't Ask: don't ask objects for data in order to do work; tell the objects to do the work Single Responsibility Principle: each object should have a narrowly defined responsibility

  Read the article

• MVC design question for forms

  - by kenny99

  Hi, I'm developing an app which has a large amount of related form data to be handled. I'm using a MVC structure and all of the related data is represented in my models, along with the handling of data validation from form submissions. I'm looking for some advice on a good way to approach laying out my controllers - basically I will have a huge form which will be broken down into manageable categories (similar to a credit card app) where the user progresses through each stage/category filling out the answers. All of these form categories are related to the main relation/object, but not to each other. Does it make more sense to have each subform/category as a method in the main controller class (which will make that one controller fairly massive), or would it be better to break each category into a subclass of the main controller? It may be just for neatness that the second approach is better, but I'm struggling to see much of a difference between either creating a new method for each category (which communicates with the model and outputs errors/success) or creating a new controller to handle the same functionality. Thanks in advance for any guidance!

  Read the article

• Handling incremental Data Modeling Changes in Functional Programming

  - by Adam Gent

  Most of the problems I have to solve in my job as a developer have to do with data modeling. For example in a OOP Web Application world I often have to change the data properties that are in a object to meet new requirements. If I'm lucky I don't even need to programmatically add new "behavior" code (functions,methods). Instead I can declarative add validation and even UI options by annotating the property (Java). In Functional Programming it seems that adding new data properties requires lots of code changes because of pattern matching and data constructors (Haskell, ML). How do I minimize this problem? This seems to be a recognized problem as Xavier Leroy states nicely on page 24 of "Objects and Classes vs. Modules" - To summarize for those that don't have a PostScript viewer it basically says FP languages are better than OOP languages for adding new behavior over data objects but OOP languages are better for adding new data objects/properties. Are there any design pattern used in FP languages to help mitigate this problem? I have read Phillip Wadler's recommendation of using Monads to help this modularity problem but I'm not sure I understand how?

  Read the article

• Spaceship objects

  - by Jam

  I'm trying to make a program which creates a spaceship and I'm using the status() method to display the ship's name and fuel values. However, it doesn't seem to be working. I think I may have messed something up with the status() method. I'm also trying to make it so that I can change the fuel values, but I don't want to create a new method to do so. I think I've taken a horrible wrong turn somewhere in there. Help please! class Ship(object): def __init__(self, name="Enterprise", fuel=0): self.name=name self.fuel=fuel print "The spaceship", name, "has arrived!" def status(): print "Name: ", self.name print "Fuel level: ", self.fuel status=staticmethod(status) def main(): ship1=Ship(raw_input("What would you like to name this ship?")) fuel_level=raw_input("How much fuel does this ship have?") if fuel_level<0: self.fuel=0 else: self.fuel(fuel_level) ship2=Ship(raw_input("What would you like to name this ship?")) fuel_level2=raw_input("How much fuel does this ship have?") if fuel_level2<0: self.fuel=0 else: self.fuel(fuel_level2) ship3=Ship(raw_input("What would you like to name this ship?")) fuel_level3=raw_input("How much fuel does this ship have?") if fuel_level3<0: self.fuel=0 else: self.fuel(fuel_level3) Ship.status() main() raw_input("Press enter to exit.")

  Read the article

• iPhone OS: Why is my managedModelObject not complying with Key Value Coding?

  - by nickthedude

  Ok so I'm trying to build this stat tracker for my app and I have built a data model object called statTracker that keeps track of all the stuff I want it to. I can set and retrieve values using the selectors, but if I try and use KVC (ie setValue: forKey: ) everything goes bad and says my StatTracker class is not KVC compliant: valueForUndefinedKey:]: the entity StatTracker is not key value coding-compliant for the key "timesLauched".' 2010-05-18 15:55:08.573 here's the code that is triggering it: NSArray *statTrackerArray = [[NSArray alloc] init]; statTrackerArray = [[CoreDataSingleton sharedCoreDataSingleton] getStatTracker]; NSNumber *number1 = [[NSNumber alloc] init]; number1 = [NSNumber numberWithInt:(1 + [[(StatTracker *)[statTrackerArray objectAtIndex:0] valueForKey:@"timesLauched"] intValue])]; [(StatTracker *)[statTrackerArray objectAtIndex:0] setValue:number1 forKey:@"timesLaunched" ]; NSError *error; if (![[[CoreDataSingleton sharedCoreDataSingleton] managedObjectContext] save:&error]) { NSLog(@"error writing to db"); } Not sure if this is enough code for you folks let me know what you need if you do need more. This would be so sweet if I could use KVC because I could then abstract all this stat tracking stuff into a single method call with a string argument for the value in question. At least that is what I hope to accomplish here. I'm actually now understanding the power of KVC but now I'm just trying to figure out how to make it work. Thanks! Nick

  Read the article

• Updating join fields in an ORM command

  - by Jono

  I have a question about object relational updates on join fields. I am working on a project using codeigniter with datamapper dmz. But I think my problem is with general understanding of ORMs. So fell free to answer with any ORM you know. I have two tables, Goods and Tags. One good can have many tags. Everything is working, but I am looking for a way to merge tags. Meaning I decide I want to remove tag A and instead have everything that is tagged by it, now be tagged by tag B. I only have models for the goods and the tags. There is no separate model for the join relationship, as I believe these ORMs were designed to work. I know how to delete a tag. But I dont know how to reach into the join table to redirect the references since there is no model for the join table. I would rather use the ORM then issuing a raw SQL command.

  Read the article

• Poor DB4O performance - What am I doing wrong?

  - by Jon

  I read Rob Conery's post about Object databases and thought I'd give it a go. I have a class lets say Book with 15 properties mostly string, some int, one Datetime and 2 decimals. I used Rob's code to open the database file etc to test on a Winforms project not a Web project. So I did the following: for(int i = 0; i < 1000000; i++) { var Book = new Book(); //Assign variables s.Save(Book); } s.CommitChanges(); This took at least a couple of minutes. I then tried to retrieve all data to test speed: var spp = s.All<Passports>(); This one line was quick, however, then doing: sppp.Count() as well as a seperate test doing a foreach loop and incrementing a counter took a couple of minutes. This seems quite slow to me. Am I doing something wrong or am I expecting too much?

  Read the article

• function objects versus function pointers

  - by kumar_m_kiran

  Hi All, I have two questions related to function objects and function pointers, Question : 1 When I read the different uses sort algorithm of STL, I see that the third parameter can be a function objects, below is an example class State { public: //... int population() const; float aveTempF() const; //... }; struct PopLess : public std::binary_function<State,State,bool> { bool operator ()( const State &a, const State &b ) const { return popLess( a, b ); } }; sort( union, union+50, PopLess() ); Question : Now, How does the statement, sort(union, union+50,PopLess()) work? PopLess() must be resolved into something like PopLess tempObject.operator() which would be same as executing the operator () function on a temporary object. I see this as, passing the return value of overloaded operation i.e bool (as in my example) to sort algorithm. So then, How does sort function resolve the third parameter in this case? Question : 2 Question Do we derive any particular advantage of using function objects versus function pointer? If we use below function pointer will it derive any disavantage? inline bool popLess( const State &a, const State &b ) { return a.population() < b.population(); } std::sort( union, union+50, popLess ); // sort by population PS : Both the above references(including example) are from book "C++ Common Knowledge: Essential Intermediate Programming" by "Stephen C. Dewhurst". I was unable to decode the topic content, thus have posted for help. Thanks in advance for your help.

  Read the article

• How do I create efficient instance variable mutators in Matlab?

  - by Trent B

  Previously, I implemented mutators as follows, however it ran spectacularly slowly on a recursive OO algorithm I'm working on, and I suspected it may have been because I was duplicating objects on every function call... is this correct? %% Example Only obj2 = tripleAllPoints(obj1) obj.pts = obj.pts * 3; obj2 = obj1 end I then tried implementing mutators without using the output object... however, it appears that in MATLAB i can't do this - the changes won't "stick" because of a scope issue? %% Example Only tripleAllPoints(obj1) obj1.pts = obj1.pts * 3; end For application purposes, an extremely simplified version of my code (which uses OO and recursion) is below. classdef myslice properties pts % array of pts nROW % number of rows nDIM % number of dimensions subs % sub-slices end % end properties methods function calcSubs(obj) obj.subs = cell(1,obj.nROW); for i=1:obj.nROW obj.subs{i} = myslice; obj.subs{i}.pts = obj.pts(1:i,2:end); end end function vol = calcVol(obj) if obj.nROW == 1 obj.volume = prod(obj.pts); else obj.volume = 0; calcSubs(obj); for i=1:obj.nROW obj.volume = obj.volume + calcVol(obj.subs{i}); end end end end % end methods end % end classdef

  Read the article

• wrapping user controls in a transaction

  - by Hans Gruber

  I'm working on heavily dynamic and configurable CMS system. Therefore, many pages are composed of a dynamically loaded set of user controls. To enable loose coupling between containers (pages) and children (user controls), all user controls are responsible for their own persistence. Each User Control is wired up to its data/service layer dependencies via IoC. They also implement an IPersistable interface, which allows the container .aspx page to issue a Save command to its children without knowledge of the number or exact nature of these user controls. Note: what follows is only pseudo-code: public class MyUserControl : IPersistable, IValidatable { public void Save() { throw new NotImplementedException(); } public bool IsValid() { throw new NotImplementedException(); } } public partial class MyPage { public void btnSave_Click(object sender, EventArgs e) { foreach (IValidatable control in Controls) { if (!control.IsValid) { throw new Exception("error"); } } foreach (IPersistable control in Controls) { if (!control.Save) { throw new Exception("error"); } } } } I'm thinking of using declarative transactions from the System.EnterpriseService namespace to wrap the btnSave_Click in a transaction in case of an exception, but I'm not sure how this might be achieved or any pitfalls to such an approach.

  Read the article

• Avoid loading unnecessary data from db into objects (web pages)

  - by GmGr

  Really newbie question coming up. Is there a standard (or good) way to deal with not needing all of the information that a database table contains loaded into every associated object. I'm thinking in the context of web pages where you're only going to use the objects to build a single page rather than an application with longer lived objects. For example, lets say you have an Article table containing id, title, author, date, summary and fullContents fields. You don't need the fullContents to be loaded into the associated objects if you're just showing a page containing a list of articles with their summaries. On the other hand if you're displaying a specific article you might want every field loaded for that one article and maybe just the titles for the other articles (e.g. for display in a recent articles sidebar). Some techniques I can think of: Don't worry about it, just load everything from the database every time. Have several different, possibly inherited, classes for each table and create the appropriate one for the situation (e.g. SummaryArticle, FullArticle). Use one class but set unused properties to null at creation if that field is not needed and be careful. Give the objects access to the database so they can load some fields on demand. Something else? All of the above seem to have fairly major disadvantages. I'm fairly new to programming, very new to OOP and totally new to databases so I might be completely missing the obvious answer here. :)

  Read the article

< Previous Page | 118 119 120 121 122 123 124 125 126 127 128 129  | Next Page >