Search Results

Search found 13829 results on 554 pages for 'temporary objects'.

Page 488/554 | < Previous Page | 484 485 486 487 488 489 490 491 492 493 494 495  | Next Page >

  • Enterprise Platform in Python, Design Advice

    - by Jason Miesionczek
    I am starting the design of a somewhat large enterprise platform in Python, and was wondering if you guys can give me some advice as to how to organize the various components and which packages would help achieve the goals of scalability, maintainability, and reliability. The system is basically a service that collects data from various outside sources, with each outside source having its own separate application. These applications would poll a central database and get any requests that have been submitted to perform on the external source. There will be a main website and REST/SOAP API that should also have access to the central data service. My initial thought was to use Django for the web site, web service and data access layer (using its built-in ORM), and then the outside source applications can use the web service(s) to get the information they need to process the request and save the results. Using this method would allow me to have multiple instances of the service applications running on the same or different machines to balance out the load. Are there more elegant means of accomplishing this? i've heard of messaging systems such as MQ, would something like that be beneficial in this scenario? My other thought was to use a completely separate data service not based on Django, and use some kind of remoting or remote objects (in they exist in Python) to interact with the data model. The downside here would be with the website which would become much slower if it had to push all of its data requests through a second layer. I would love to hear what other developers have come up with to achieve these goals in the most flexible way possible.

    Read the article

  • Flex + PHP + ValueObjects

    - by Tempname
    I have a php/flex value object that I am using to transmit data to/from in my application. Everything works great php-flex, but I am having an issue with flex-php. In my MergeTemplateService.php service I have the following code. This is the method that flex hits directly: function updateTemplate($valueObject){ $object = DAOFactory::getMergeTemplateDAO()->update($valueObject); return $object; } I am passing a value object that from flex looks like this: (com.rottmanj.vo::MergeTemplateVO)#0 communityID = 0 creationDate = (null) enterpriseID = 0 lastModifyDate = (null) templateID = 2 templateName = "My New Test Template" userID = 0 The issue I am having is that my updateTemplate method sees the value object as an array and not an object. In my amfphp globals.php I have set my voPath as: $voPath = "services/class/dto/"; Any help with this is greatly appreciated Here are my two value objects: AS3 VO: package com.rottmanj.vo { [RemoteClass(alias="MergeTemplate")] public class MergeTemplateVO { public var templateID:int; public var templateName:String; public var communityID:int; public var enterpriseID:int; public var userID:int; public var creationDate:String; public var lastModifyDate:String public function MergeTemplateVO(data:Object = null):void { if(data != null) { templateID = data.templateID; templateName = data.templateName; communityID = data.communityID; enterpriseID = data.enterpriseID; userID = data.userID; creationDate = data.creationDate; lastModifyDate = data.lastModifyDate; } } } } PHPVO: <?php class MergeTemplate{ var $templateID; var $templateName; var $communityID; var $enterpriseID; var $userID; var $creationDate; var $lastModifyDate; var $_explictType = 'MergeTemplate'; } ?>

    Read the article

  • How long is the time frame between context switches on Windows?

    - by mattcodes
    Reading CLR via C# 2.0 (I dont have 3.0 with me at the moment) Is this still the case: If there is only one CPU in a computer, only one thread can run at any one time. Windows has to keep track of the thread objects, and every so often, Windows has to decide which thread to schedule next to go to the CPU. This is additional code that has to execute once every 20 milliseconds or so. When Windows makes a CPU stop executing one thread's code and start executing another thread's code, we call this a context switch. A context switch is fairly expensive because the operating system has to: So circa CLR via C# 2.0 lets say we are on Pentium 4 2.4ghz 1 core non-HT, XP. Every 20 milliseconds? Where a CLR thread or Java thread is mapped to an OS thread only a maximum of 50 threads per second may get a chance to to run? I've read that context switching is very fast in mircoseconds here on SO, but how often roughly (magnitude style guesses) will say a modest 5 year old server Windows 2003 Pentium Xeon single core give the OS the opportunity to context switch? 20ms in the right area? I dont need exact figures I just want to be sure that's in the right area, seems rather long to me.

    Read the article

  • What is the best way to remove flickering from a fast series of image loads in Flash?

    - by msandbot
    Hi, working on making a flash program that loads about 1000 jpegs and then plays them like a movie. Have all the buttons and stuff working but the time it takes for an image to load is so high that the movie can't be played at 30 fps. I've tried multiple ways of fixing this using 1 scrollpane and changing its source ever 30 ms. This one is the worst but simplest. Flickers cause strobing and it is unwatchable. used 2 scrollpanes that were duplicates of each other until I had to load. I would then make that one invisible, load it , then make it visible. Then load the background one. Works but same problem as the first at high speeds, just less severe. used 1 scrollpane per image . This works great, except that it fails miserably on any more than 100 of them due to the number of objects. Has anyone else experienced/solved/wants to help me solve this? None of my fixes have worked. Currently using action script 3, but will change if its not possible in that. Also, I want to be able to zoom in and then scroll around the window hence the scrollpanes, but if that's not possible its a sacrifice I'm willing to make

    Read the article

  • C#: Non-constructed generics as properties (eg. List<T>)

    - by Dav
    The Problem It's something I came across a while back and was able to work around it somehow. But now it came back, feeding on my curiosity - and I'd love to have a definite answer. Basically, I have a generic dgv BaseGridView<T> : DataGridView where T : class. Constructed types based on the BaseGridView (such as InvoiceGridView : BaseGridView<Invoice>) are later used in the application to display different business objects using the shared functionality provided by BaseGridView (like virtual mode, buttons, etc.). It now became necessary to create a user control that references those constructed types to control some of the shared functionality (eg. filtering) from BaseGridView. I was therefore hoping to create a public property on the user control that would enable me to attach it to any BaseGridView in Designer/code: public BaseGridView<T> MyGridView { get; set; }. The trouble is, it doesn't work :-) When compiled, I get the following message: The type or namespace name 'T' could not be found (are you missing a using directive or an assembly reference?) Solutions? I realise I could extract the shared functionality to an interface, mark BaseGridView as implementing that interface, and then refer to the created interface in my uesr control. But I'm curious if there exists some arcane C# command/syntax that would help me achieve what I want - without polluting my solution with an interface I don't really need :-)

    Read the article

  • Automatically creating DynaActionForms in Mockrunner via struts-config.xml

    - by T Reddy
    I'm switching from MockStrutsTestCase to Mockrunner and I'm finding that having to manually re-create all of my DynaActionForms in Mockrunner is a pain...there has to be an easier way?! Can somebody offer a tip to simplify this process? For instance, this form bean definition in struts-config.xml: <form-bean name="myForm" type="org.apache.struts.action.DynaActionForm"> <form-property name="property" type="java.lang.String"/> </form-bean> results in this code in Mockrunner: //define form config FormBeanConfig config = new FormBeanConfig(); config.setName("myForm"); config.setType(DynaActionForm.class.getName()); FormPropertyConfig property = new FormPropertyConfig(); property.setName("property"); property.setType("java.lang.String"); config.addFormPropertyConfig(property); //create mockrunner objects ActionMockObjectFactory factory = new ActionMockObjectFactory(); ActionTestModule module = new ActionTestModule(factory); DynaActionForm form = module.createDynaActionForm(config); Now imagine that I have dozens of DynaActionForms with dozens of attributes...that stinks!

    Read the article

  • best web database solution for scala for a high traffic site?

    - by egervari
    I am in charge of a rebuilding a website that gets about 250,000 visitors a day. We'd like to use Scala, but it does not work very well with Spring (in some minor cases) and Hibernate (there is a major and very annoying mismatch here if you want to use scala collections, which we do). The application itself is going to have about 40-50 tables. Other than Hibernate, is there an ORM that works awesome with Scala and is as performant and reliable as Hibernate? Does it also have the same capabilities, or are we going to run into leaky-abstractions if we don't use Hibernate? It would be a big risk for us to go with a framework that is newer and doesn't seem to have a lot of industry backing... and at the same time, Hibernate is a real pain to program against when using Scala. 1) The Java Collection <- Scala Collection is absolutely painful. There is a lot more boilerplate and crap to write. 2) The IDE doesn't import JavaConversions and java interfaces automatically... so we this needs to be done manually. Optimizing Imports in IDEA is going to destroy all the manual work. 3) There is also a performance cost to converting back and forth all the time in your domain objects and your dao classes. 4) Not to mention there needs to be a lot of casting, which produces code ugly as sin. I actually would love to write my own orm that is 100% tailored to scala, but obviously this is really outside of the scope of our project for now. So what is the best approach?

    Read the article

  • assembling an object graph without an ORM -- in the service layer or data layer?

    - by Hans Gruber
    At my current gig, our persistence layer uses IBatis going against SQL Server stored procedures (puke). IMHO, this approach has many disadvantages over the use of a "true" ORM such NHibernate or EF, but the one I'm trying to address here revolves around all the boilerplate code needed to map data from a result set into an object graph. Say I have the following DTO object graph I want to return to my presentation layer: IEnumerable<CustomerDTO> |--> IEnumerable<AddressDTO> |--> LatestOrderDTO The way I've implemented this is to have a discrete method in my DAO class to return each IEnumerable<*DTO>, and then have my service class be responsible for orchestrating the calls to the DAO. It then returns the fully assembled object graph to the client: public class SomeService(){ public SomeService(IDao someDao){ this._someDao = someDao; } public IEnumerable<CustomerDTO> ListCustomersForHistory(int brokerId){ var customers = _someDao.ListCustomersForBroker(brokerId); foreach (customer in customers){ customer.Addresses = someDao.ListCustomersAddresses(brokerId); customer.LatestOrder = someDao.GetCustomerLatestOrder(brokerId); } } return customers; } My question is should this logic belong in the service layer or the should I make my DAO such that it instead returns the assembled object graph. If I was using NHibernate, I assume that this kind of relationship association between objects comes for "free"?

    Read the article

  • How much is too much memory allocation in NDK?

    - by Maximus
    The NDK download page notes that, "Typical good candidates for the NDK are self-contained, CPU-intensive operations that don't allocate much memory, such as signal processing, physics simulation, and so on." I came from a C background and was excited to try to use the NDK to operate most of my OpenGL ES functions and any native functions related to physics, animation of vertices, etc... I'm finding that I'm relying quite a bit on Native code and wondering if I may be making some mistakes. I've had no trouble with testing at this point, but I'm curious if I may run into problems in the future. For example, I have game struct defined (somewhat like is seen in the San-Angeles example). I'm loading vertex information for objects dynamically (just what is needed for an active game area) so there's quite a bit of memory allocation happening for vertices, normals, texture coordinates, indices and texture graphic data... just to name the essentials. I'm quite careful about freeing what is allocated between game areas. Would I be safer setting some caps on array sizes or should I charge bravely forward as I'm going now?

    Read the article

  • Scalability 101: How can I design a scalable web application using PHP?

    - by Legend
    I am building a web-application and have a couple of quick questions. From what I learnt, one should not worry about scalability when initially building the app and should only start worrying when the traffic increases. However, this being my first web-application, I am not quite sure if I should take an approach where I design things in an ad-hoc manner and later "fix" them. I have been reading stories about how people start off with an app that gets millions of users in a week or two. Not that I will face the same situation but I can't help but wonder, how do these people do it? Currently, I bought a shared hosting account on Lunarpages and that got me started in building and testing the application. However, I am interested in learning how to build the same application in a scalable-manner using the cloud, for instance, Amazon's EC2. From my understanding, I can see a couple of components: There is a load balancer that first receives requests and then decides where to route each request This request is then handled by a server replica that then processes the request and updates (if required) the database and sends back the response to the client If a similar request comes in, then a caching mechanism like memcached kicks into picture and returns objects from the cache A blackbox that handles database replication Specifically, I am trying to do the following: Setting up a load balancer (my homework revealed that HAProxy is one such load balancer) Setting up replication so that databases can be synchronized Using memcached Configuring Apache to work with multiple web servers Partitioning application to use Amazon EC2 and Amazon S3 (my application is something that will need great deal of storage) Finally, how can I avoid burning myself when using Amazon services? Because this is just a learning phase, I can probably do with 2-3 servers with a simple load balancer and replication but until I want to avoid paying loads of money accidentally. I am able to find resources on individual topics but am unable to find something that starts off from the big picture. Can someone please help me get started?

    Read the article

  • After calling a COM-dll component, C# exceptions are not caught by the debugger

    - by shlomil
    I'm using a COM dll provided to me by 3rd-party software company (I don't have the source code). I do know for sure they used Java to implement it because their objects contain property names like 'JvmVersion'. After I instantiated an object introduced by the provided COM dll, all exceptions in my C# program cannot be caught by the VS debugger and every time an exception occurs I get the default Windows Debugger Selection dialog (And that's while executing my program in debug mode under a full VisualStudio debugging environment). To illustrate: throw new Exception("exception 1"); m_moo = new moo(); // Component taken from the COM-dll throw new Exception("exception 2"); Exception 1 will be caught by VS and show the "yellow exception window". Exception 2 will open a dialog titled "Visual Studio Just-In-Time Debugger" containing the text "An unhandled win32 exception occurred in myfile.vshost.exe[1348]." followed by a list of the existing VS instances on my system to select from. I guess the instantiation of "moo" object overrides C#'s exception handler or something like that. Am I correct and is there a way to preserve C#'s exception handler?

    Read the article

  • Create a variable which is named depending on an ID number?

    - by gray
    Is there any way to create a variable, and add an ID to the end of the actual variable name? I have a variable called 'gauge', used to create a new Gauge object: var gauge = new Gauge(target).setOptions(opts); I want to add an ID to the variable, so something like: var gauge+id = new Gauge(target).setOptions(opts); It's because I'm creating a number of these objects, and have a specific ID already for each one, which I want to attach to the gauge object if possible? All my code for this function is below, if it gives you a better idea of what i need to do: function go(id, votes) { var val = $('#votes_'+id).text(); var target = document.getElementById('foo_'+id); // your canvas element var gauge = new Gauge(target).setOptions(opts); // create sexy gauge! gauge.maxValue = 100; // set max gauge value gauge.animationSpeed = 20; // set animation speed (32 is default value) var a=votes+0.5; gauge.set(val); // set actual value } My main problem arises on the last line. It says gauge.set(val), and it only sets the last object, ignoring all the other ones...

    Read the article

  • Move to php in windows? Concern, hints, "please don't do!"?

    - by Daniel
    I am considering to move frome Microsoft languages to PHP (just for web dev) which has quite an interesting syntax, a perlish look (but a wider programmer base) and it allows me to reuse the web without reinventing it. I have some concerns too. I would be more than happy to gather some wisdom from stackoverflow community, (challenge to my opinions warmly welcome). Here are my doubts. Efficiency. Cgi are slow, what I am supposed to use? Fastcgi? Or what else? Efficiency + stability. Is PHP on windows really stable and a good choice in terms of performances? Database. I use very often MSSQL (I regret, i like it). Could I widely and efficiently interface PHP with MSSQL (using smartly stored pro, for example). XSLT + XML performance. I work quite a lot with XML and XSLT and I really find the MS xml parser a great software component. Are parser used in PHP fast, reliable and efficient (I am interested mainly in DOM, not SAX)? Objects. Is the PHP object programming model valid end efficient? 6 Regex. How efficient is PHP processing regexp? Many thanks for your advices.

    Read the article

  • Linq - reuse expression on child property

    - by user175528
    Not sure if what I am trying is possible or not, but I'd like to reuse a linq expression on an objects parent property. With the given classes: class Parent { int Id { get; set; } IList<Child> Children { get; set; } string Name { get; set; } } class Child{ int Id { get; set; } Parent Dad { get; set; } string Name { get; set; } } If i then have a helper Expression<Func<Parent,bool> ParentQuery() { Expression<Func<Parent,bool> q = p => p.Name=="foo"; } I then want to use this when querying data out for a child, along the lines of: using(var context=new Entities.Context) { var data=context.Child.Where(c => c.Name=="bar" && c.Dad.Where(ParentQuery)); } I know I can do that on child collections: using(var context=new Entities.Context) { var data=context.Parent.Where(p => p.Name=="foo" && p.Childen.Where(childQuery)); } but cant see any way to do this on a property that isnt a collection. This is just a simplified example, actually the ParentQuery will be more complex and I want to avoid having this repeated in multiple places as rather than just having 2 layers I'll have closer to 5 or 6, but all of them will need to reference the parent query to ensure security.

    Read the article

  • Which is the correct design pattern for my PHP application?

    - by user1487141
    I've been struggling to find good way to implement my system which essentially matches the season and episode number of a show from a string, you can see the current working code here: https://github.com/huddy/tvfilename I'm currently rewriting this library and want a nicer way to implement how the the match happens, currently essentially the way it works is: There's a folder with classes in it (called handlers), every handler is a class that implements an interface to ensure a method called match(); exists, this match method uses the regex stored in a property of that handler class (of which there are many) to try and match a season and episode. The class loads all of these handlers by instantiating each one into a array stored in a property, when I want to try and match some strings the method iterates over these objects calling match(); and the first one that returns true is then returned in a result set with the season and episode it matched. I don't really like this way of doing it, it's kind of hacky to me, and I'm hoping a design pattern can help, my ultimate goal is to do this using best practices and I wondered which one I should use? The other problems that exist are: More than one handler could match a string, so they have to be in an order to prevent the more greedy ones matching first, not sure if this is solvable as some of the regex patterns have to be greedy, but possibly a score system, something that shows a percentage of how likely the match is correct, i'd have no idea how to actually implement this though. I'm not if instantiating all those handlers is a good way of doing it, speed is important, but using best practices and sticking to design patterns to create good, extensible and maintainable code is my ultimate priority. It's worth noting the handler classes sometimes do other things than just regex matching, they sometimes prep the string to be matched by removing common words etc. Cheers for any help Billy

    Read the article

  • Effective communication in a component-based system

    - by Tesserex
    Yes, this is another question about my game engine, which is coming along very nicely, with much thanks to you guys. So, if you watched the video (or didn't), the objects in the game are composed of various components for things like position, sprites, movement, collision, sounds, health, etc. I have several message types defined for "tell" type communication between entities and components, but this only goes so far. There are plenty of times when I just need to ask for something, for example an entity's position. There are dozens of lines in my code that look like this: SomeComponent comp = (SomeComponent)entity.GetComponent(typeof(SomeComponent)); if (comp != null) comp.GetSomething(); I know this is very ugly, and I know that casting smells of improper OO design. But as complex as things are, there doesn't seem to be a better way. I could of course "hard-code" my component types and just have SomeComponent comp = entity.GetSomeComponent(); but that seems like a cop-out, and a bad one. I literally JUST REALIZED, while writing this, after having my code this way for months with no solution, that a generic will help me. SomeComponent comp = entity.GetComponent<SomeComponent>(); Amazing how that works. Anyway, this is still only a semantic improvement. My questions remain. Is this actually that bad? What's a better alternative?

    Read the article

  • Java reflection appropriateness

    - by jsn
    This may be a fairly subjective question, but maybe not. My application contains a bunch of forms that are displayed to the user at different times. Each form is a class of its own. Typically the user clicks a button, which launches a new form. I have a convenience function that builds these buttons, you call it like this: buildButton( "button text", new SelectionAdapter() { @Override public void widgetSelected( SelectionEvent e ) { showForm( new TasksForm( args... ) ); } } ); I do this dozens of times, and it's really cumbersome having to make a SelectionAdapter every time. Really all I need for the button to know is what class to instantiate when it's clicked and what arguments to give the constructor, so I built a function that I call like this instead: buildButton( "button text", TasksForm.class, args... ); Where args is an arbitrary list of objects that you could use to instantiate TasksForm normally. It uses reflection to get a constructor from the class, match the argument list, and build an instance when it needs to. Most of the time I don't have to pass any arguments to the constructor at all. The downside is obviously that if I'm passing a bad set of arguments, it can't detect that at compilation time, so if it fails, a dialog is displayed at runtime. But it won't normally fail, and it'll be easy to debug if it does. I think this is much cleaner because I come from languages where the use of function and class literals is pretty common. But if you're a normal Java programmer, would seeing this freak you out, or would you appreciate not having to scan a zillion SelectionAdapters?

    Read the article

  • Android - Memory leak when dynamically building UI with image resource backgrounds

    - by Rich
    I have an Activity that I swear is leaking memory. The app I'm working on does a lot with images, so I've had to be pretty stingy with memory when working directly with Bitmaps. I added an Activity, and now if you use this new Activity it basically puts me over the edge with mem usage and I end up throwing the "Bitmap exceeds VM budget" exception. If you never launch this Activity, everything is smooth as it was previously. I started reading about memory leaks, and I think that I have a similar situation to what is described in the article in the Android docs. I'm dynamically creating a bunch of image views and adding a BackgroundDrawable from the resources and adding an OnClickListener as well. I imagine I have to do some cleanup when the Activity hits onPause in its life cycle, but I'd like to know specifically what is the correct way. Here is the code that should demonstrate the objects I'm working with... LinearLayout templateContainer; . . . ImageView imgTemplatePreview = (ImageView) item.findViewById(R.id.imgTemplatePreview); . . . imgTemplatePreview.setBackgroundDrawable(getResources().getDrawable(previewId)); imgTemplatePreview.setOnClickListener(imgClick); templateContainer.addView(item);

    Read the article

  • object.valid? returns false but object.errors.full_messages is empty

    - by user549563
    Hello I'm confuse about objects that I can't save, simplified model is class Subscription < ActiveRecord::base belongs_to :user, :class_name => "User", :foreign_key => "user_id" has_many :transactions, :class_name => "SubscriptionTransaction" validates_presence_of :first_name, :message => "ne peut être vide" validates_presence_of :last_name, :message => "ne peut être vide" validates_presence_of :card_number, :message => "ne peut être vide" validates_presence_of :card_verification, :message => "ne peut être vide" validates_presence_of :card_type, :message => "ne peut être vide" validates_presence_of :card_expires_on, :message => "ne peut être vide" attr_accessor :card_number, :card_verification validate_on_create :validate_card def validate_card unless credit_card.valid? credit_card.errors.full_messages.each do |message| errors.add_to_base message end end end def credit_card @credit_card ||= ActiveMerchant::Billing::CreditCard.new( :type => card_type, :number => card_number, :verification_value => card_verification, :month => card_expires_on.month, :year => card_expires_on.year, :first_name => first_name, :last_name => last_name ) end end and in my subscription_controller if subscription.save # do something else debugger # means breakpoint where i try subscription.errors.full_messages # do something else end I tried to use ruby-debug for this adding a breakpoint before. And subscription.valid? return false which explains that ActiveRecord doesn't allow the save method. Unfortunately i can't know why the object is invalid. subscription.errors.full_messages # => [] I'm stucked, if you have any idea, thank you.

    Read the article

  • FileConnection Blackberry memory usage

    - by Dean
    Hello, I'm writing a blackberry application that reads ints and strings out of a database. This is my first time dealing with reading/writing on the blackberry, so forgive me if this is a dumb question. The database file I'm reading is only about 4kB I open the file with the following code fconn = (FileConnection) Connector.open("file_path_here", Connector.READ); if(fconn.exists()==false){fconn.close();return;} is = fconn.openDataInputStream(); while(!eof){ //etc... } is.close(); fconn.close(); The problem is, this code appears to be eating a LOT of memory. Using breakpoints and the "Memory Statistics" view, I determined the following: calling "Connector.open" creates 71 objects and changes "RAM Bytes in use" by 5376 calling "fconn.openDataInputStream();" increases RAM usage by a whopping 75920 Is this normal? Or am I doing something wrong? And how can I fix this? 75MB of RAM is a LOT of memory to waste on a handheld device, especially when the file I'm reading is only 4kB and I haven't even begun reading any data! How is this even possible?

    Read the article

  • How to manage large amounts of delegates and usercallbacks in C# async http library

    - by Tyler
    I'm coding a .NET library in C# for communicating with XBMC via its JSON RPC interface using HTTP. I coded and released a preliminary version but everything is done synchronously. I then recoded the library to be asynchronous for my own purposes as I was/am building an XBMC remote for WP7. I now want to release the new async library but want to make sure it's nice and tidy before I do. Due to the async nature a user initiates a request, supplies a callback method that matches my delegate and then handles the response once it's been received. The problem I have is that within the library I track a RequestState object for the lifetime of the request, it contains the http request/response as well as the user callback etc. as member variables, this would be fine if only one type of object was coming back but depending on what the user calls they may be returned a list of songs or a list of movies etc. My implementation at the moment uses a single delegate ResponseDataRecieved which has a single parameter which is a simple Object - As this has only be used by me I know which methods return what and when I handle the response I cast said object to the type I know it really is - List, List etc. A third party shouldn't have to do this though - The delegate signature should contain the correct type of object. So then I need a delegate for every type of response data that can be returned to the third party - The specific problem is, how do I handle this gracefully internally - Do I have a bunch of different RequestState objects that each have a different member variable for the different delegates? That doesn't "feel" right. I just don't know how to do this gracefully and cleanly.

    Read the article

  • Issue with class design to model user preferences for different classes

    - by Mulone
    Hi all, I'm not sure how to design a couple of classes in my app. Basically that's a situation: each user can have many preferences each preference can be referred to an object of different classes (e.g. album, film, book etc) the preference is expressed as a set of values (e.g. score, etc). The problem is that many users can have preferences on the same objects, e.g.: John: score=5 for filmid=apocalypsenow Paul: score=3 for filmid=apocalypsenow And naturally I don't want to duplicate the object film in each user. So I could create a class called "preference" holding a score and then a target object, something like: User{ hasMany preferences } Preference{ belongsTo User double score Film target Album target //etc } and then define just one target. Then I would create an interface for the target Classes (album, film etc): Interface canBePreferred{ hasMany preferences } And implement all of those classes. This could work, but it looks pretty ugly and it would requires a lot of joins to work. Do you have some patterns I could use to model this nicely? Cheers, Mulone

    Read the article

  • Flex Tree with infinite parents and children

    - by Tempname
    I am working on a tree component and I am having a bit of the issue with populating the data-provider for this tree. The data that I get back from my database is a simple array of value objects. Each value object has 2 properties. ObjectID and ParentID. For parents the ParentID is null and for children the ParentID is the ObjectID of the parent. Any help with this is greatly appreciated. Essentially the tree should look something like this: Parent1 Child1 Child1 Child2 Child1 Child2 Parent2 Child1 Child2 Child3 Child1 This is the current code that I am testing with: public function setDataProvider(data:Array):void { var tree:Array = new Array(); for(var i:Number = 0; i < data.length; i++) { // do the top level array if(!data[i].parentID) { tree.push(data[i], getChildren(data[i].objectID, data)); } } function getChildren(objectID:Number, data:Array):Array { var childArr:Array = new Array(); for(var k:Number = 0; k < data.length; k++) { if(data[k].parentID == objectID) { childArr.push(data[k]); //getChildren(data[k].objectID, data); } } return childArr; } trace(ObjectUtil.toString(tree)); } Here is a cross section of my data: ObjectID ParentID 1 NULL 10 NULL 8 NULL 6 NULL 4 6 3 6 9 6 2 6 11 7 7 8 5 8

    Read the article

  • Can Haskell's monads be thought of as using and returning a hidden state parameter?

    - by AJM
    I don't understand the exact algebra and theory behind Haskell's monads. However, when I think about functional programming in general I get the impression that state would be modelled by taking an initial state and generating a copy of it to represent the next state. This is like when one list is appended to another; neither list gets modified, but a third list is created and returned. Is it therefore valid to think of monadic operations as implicitly taking an initial state object as a parameter and implicitly returning a final state object? These state objects would be hidden so that the programmer doesn't have to worry about them and to control how they gets accessed. So, the programmer would not try to copy the object representing the IO stream as it was ten minutes ago. In other words, if we have this code: main = do putStrLn "Enter your name:" name <- getLine putStrLn ( "Hello " ++ name ) ...is it OK to think of the IO monad and the "do" syntax as representing this style of code? putStrLn :: IOState -> String -> IOState getLine :: IOState -> (IOState, String) main :: IOState -> IOState -- main returns an IOState we can call "state3" main state0 = putStrLn state2 ("Hello " ++ name) where (state2, name) = getLine state1 state1 = putStrLn state0 "Enter your name:"

    Read the article

  • JavaScript onClick() Display

    - by junaidkaps
    I have an array consisting of several objects containing Strings. I am successfully able to display the array by using: <td><p onclick="theMiddle(this)">The Middle</td> As you see from the td tag this is part of a table. Issue is that the browser opens up a new page to display my text. I have been trying to display the array above my table in a p tag. //JavaScript var arrayTheMiddle = new Array (showName.theMiddle, beginingTime.theMiddle, network.abc, duration.thirty, rating.general, description.theMiddle, showImage.theMiddle); function theMiddle(obj){ for(i=0; i < arrayTheMiddle.length; i++) { document.write(arrayTheMiddle[i] + "<br>"); } } //HTML File <p>Would like the array/function displayed here while the user clicks within the table below (entire table has not been listed)</p> <td><p onclick="theMiddle(this)">The Middle</td> Unfortunately I am constantly failing at utilizing get element by id to call my function which consists of an array. I have searched for all sorts of stuff, yet frankly I'm lost. Not even sure if my approach is correct at this point. I'm sure this is one of those simple things that are blowing over my head!

    Read the article

< Previous Page | 484 485 486 487 488 489 490 491 492 493 494 495  | Next Page >