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  • What design considerations should one take to receive text and multiple attachments via web?

    - by ramesh.nagul
    I am developing a web application to accept a bunch of text and attachments (1 or more) via email, web and other methods. I am planning to build a single interface, mostly a web service to accept this content. What design considerations should I make? I am building the app using ASP.NET MVC 2. Should the attachments be saved to disk or in the database? Should the unified single interface be a web service? Pros and cons to using web services to upload files

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  • Do you know of a free .Net component for visual flow model graph design and editing?

    - by Ivan
    An app (C#4, WinForms, Entity Framework, SQL Server 2008) of mine maintains a graph of interconnected objects, each having some simple member fields and a set of many directed (in and out) one-to-one links to other objects. I'd like to offer a user an ability to view and edit this graph visually some way, creating and removing connections, modifying objects attributes values and introducing/dropping objects. I suppose there has to be a framework (at list a primitive kind of) for this as visual model design tools are pretty common to meet. Do you know one?

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  • What is the best tool to achieve this API design?

    - by Jose Fernandez
    Our web app offers a service that allows a "Publisher" to create a website (we give them a CMS system) that is ready to provide this service to "Members" (think Shopify). We have some possible clients that wish to become "Publishers" but they already have existing websites (vbulletin, word press blog, etc) with their own user base. We wish to develop an API that would allow these "Publishers" to keep using their own websites, and embed our services into them. Our main business requirement is that once "Members" are logged into the "Publishers" existing system, they should be able to also access our website without having to log-in again OR have to create another account there. The process should be seamless to the "Member" and "Publishers" should not have to sync their user base with our system. We also want to use an existing API authentication/authorization system instead of creating our own (OAuth, OpenID, etc) What would be the best way to use OAuth to achieve this sigle-sign on design? If OAuth is not the best tool, is there any other one out there that fits our requirements?

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  • iPhone interface design considerations: checkbox and drop-down menu ?

    - by Jesse Armand
    This may not be a programming question, but I don't know where to ask for this and it's still related. We all know that the checkbox and drop-down menu is a UI paradigm brought in from HTML or web interface. I'm not asking for code implementations here. A google search had produced many results. Although if anyone is willing to share that's great. So the question is: Is this a good design approach if we just want to provide a checkbox or drop-down functionality? (e.g. for quizzes, or forms)

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  • Big table or multiple separate tables? (database design question)

    - by Khou
    This is a database design question. I want to build an invoice web application, an invoice can have many items, and each user can have an inventory list of product items that they can store and choose to add to an invoice item. My questions are: 1. Should I store all product inventory for all users using my application under one single table? Or have a separate product inventory table created for each user? 2. Is this even possible? 1 table is easier, but what if this single table grows too big, will I have a problem? (primary key INT).

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  • Custom components vs default components in GUI Design. Which is more practical? (.NET)

    - by AlexRednic
    Ok, so is it better to create my own components (Either inherit them from existing ones or creating them from scratch) or to use the ones that come by default? I'm asking this under the umbrella of scalability, overhead and other factors that my contribute on each of the choices. UPDATE: Sorry if I'm to vague. I don't really know how to explain myself better. Isn't it a good idea to inherit each default component? For example what if I'm to design a rather large application and for example i need to change the display format on a DateTimePicker. Wouldn't it better to think ahead and inherit it and use the inherited component instead of the defaults? But, wouldn't it add a lot of overhead in small applications?

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  • How do I design a .NET (C#) for a program that needs to run as a Windows service but also have a web

    - by hjoelr
    I am designing a piece of software that needs to operate different pieces of hardware based mainly on a schedule but it also needs to have a web interface for configuring settings, configuring the schedule, and possibly even manually controlling the hardware. I'm not sure how to design the architecture of software like this. One thought that I have had was to create a Windows service that does the communication with the hardware as well as "publishing" web services through WCF and then having an ASP.NET application that then controls the Windows service through WCF. This approach seems to be a lot of work for what I'm trying to accomplish. Could someone please give me some direction whether or not this is a good approach, and even give me a better way to do it if one exists? Thanks! Joel

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  • How do I design a web service (microsoft) that can be consumed by multiple end points?

    - by Ben McCormack
    My company is planning to implement a solution in multiple applications that will help to validate mailing addresses at the point of data entry. We're using UPS's Extended Address Validation (XAV) web service API to validate the addresses. Our current plan is to build a .NET web service that can be used to communicate between our applications and the UPS API. We have applications in VB6, classic ASP, and .NET 2.0, so we'd like to implement a solution that can be easily consumed by each of these programming environments. What are our (Microsoft) options for designing a web service that can be consumed by multiple clients? In particular, is there a way to design a single web service that can respond with JSON (in case we want to validate our web page using javascript) in addition to XML? I'm new to designing web services and want to make sure we consider all of our options. I've heard terms like asmx, WCF, OData, etc., but I don't know which frameworks will support what we're trying to do and where to start.

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  • Does XAML design mode support more color than code view?

    - by Rahul Soni
    While working with SilverLight using Visual Studio 10, I found that in design mode XAML allows a wide plethora of colors. For ex. Lime is a valid color in XAML. <LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5"> <GradientStop Color="Yellow" Offset="0" /> <GradientStop Color="Lime" Offset="1" /> While working with code though, I found that Lime and many other colors are missing... GradientStop blueGS = new GradientStop(); blueGS.Color = Colors.Lime; What am I missing? Both of these colors belong to System.Windows.Media.Colors.

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  • Background Image displaying in Design view but not in browser? (Visual Studio 2008)

    - by Tom Hutchinson
    I'm new to CSS and this issue in Visual Studio is driving me mad! I have a background image defined within a simple style sheet... body { background-image: url(Images\Greenhouse.jpg); background-position: center; } My style sheet is referenced within the HTML code... <head runat="server"> <title></title> <link rel="Stylesheet" type="text/css" href="Stylesheet.css"/> </head> The background image shows in design view but in the browser, nothing! I've tried changing position etc and refreshed the browser, cleared the cache etc. This happens with all my images. Images are within the project folder (\Images) and added to the solution explorer in VS. Tried "", changing image file names etc, nothing is working!

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  • How to design service that can provide interface as JAX-WS web service, or via JMS, or as local meth

    - by kevinegham
    Using a typical JEE framework, how do I develop and deploy a service that can be called as a web service (with a WSDL interface), be invoked via JMS messages, or called directly from another service in the same container? Here's some more context: Currently I am responsible for a service (let's call it Service X) with the following properties: Interface definition is a human readable document kept up-to-date manually. Accepts HTTP form-encoded requests to a single URL. Sends plain old XML responses (no schema). Uses Apache to accept requests + a proprietary application server (not servlet or EJB based) containing all logic which runs in a seperate tier. Makes heavy use of a relational database. Called both by internal applications written in a variety of languages and also by a small number of third-parties. I want to (or at least, have been told to!): Switch to a well-known (pref. open source) JEE stack such as JBoss, Glassfish, etc. Split Service X into Service A and Service B so that we can take Service B down for maintenance without affecting Service A. Note that Service B will depend on (i.e. need to make requests to) Service A. Make both services easier for third parties to integrate with by providing at least a WS-I style interface (WSDL + SOAP + XML + HTTP) and probably a JMS interface too. In future we might consider a more lightweight API too (REST + JSON? Google Protocol Buffers?) but that's a nice to have. Additional consideration are: On a smaller deployment, Service A and Service B will likely to running on the same machine and it would seem rather silly for them to use HTTP or a message bus to communicate; better if they could run in the same container and make method calls to each other. Backwards compatibility with the existing ad-hoc Service X interface is not required, and we're not planning on re-using too much of the existing code for the new services. I'm happy with either contract-first (WSDL I guess) or (annotated) code-first development. Apologies if my terminology is a bit hazy - I'm pretty experienced with Java and web programming in general, but am finding it quite hard to get up to speed with all this enterprise / SOA stuff - it seems I have a lot to learn! I'm also not very used to using a framework rather than simply writing code that calls some packages to do things. I've got as far as downloading Glassfish, knocking up a simple WSDL file and using wsimport + a little dummy code to turn that into a WAR file which I've deployed.

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  • XAML : How to change background color only in Design mode?

    - by Kave
    I have a control with white text foreground color and transparent background color. Later on this usercontrol will be added into a different control that carries the real background color. However during designing this, control due white foreground on white background in VS 2010, I can't obviously see anything. In there anyway to define a different color for just the design time? I have tried this: if (System.ComponentModel.DesignerProperties.IsInDesignTool) { LayoutRoot.Background = new SolidColorBrush(Colors.Blue); } But this doesn't work. Any tips? Thanks, Kave

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  • Is there any project estimator tool to give estimate for web design/ developemnt work?

    - by jitendra
    Is there any project estimator tool to give estimate for web design/ development work? I don't have to calculate Price jusr want to calculate estimated time. for things like Just for example Page creation (layout in XHTML) CSS creation Content creation (Word to HTML including images in some pages) Bulk PDF upload PHP Script for Form Testing all pages I need like Items Quantity Time for each task(min.) Estimated total (in hour) PDF upload x 30 = 2 min = 60 Min pages with images x 30 = 15 min for each = 60 Min is there any simple jquery calculator power with jquery . Where we can add add remove custom thing to calculate time.? or any other free online/offline tool

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  • mysql database design: thread and reply of a reply?

    - by ajsie
    in my forum i have threads and replies. one thread has multiple replies. but then, a reply can be a reply of an reply (like google wave). because of that a reply has to have a column "reply_id" so it can point to the parent reply. but then, the "top-level" replies (the replies directly under the thread) will have no parent reply. so how can i fix this? how should the columns be in the reply table (and thread table). at the moment it looks like this: threads: id title body replies: id thread_id (all replies will belong to a thread) reply_id (here lies the problem. the top-level replies wont have a parent reply) body what could a smart design look like to enable reply a reply?

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  • Creating a form with floats, what is the general design when you need 2 columns, p and label?

    - by Blankman
    I want to design a form. The form has 3 sections: user info, shipping and billing. Each section will have 2 columns, so form fields and their labels with be on both the left and right side. What technique should I use? How does this look? <div id="forms"> <div id=contact> <div class=left> <p><label>Firstname<label><input type=text /></p> </div> <div class=right></div> </div> <div id=shipping></div> <div id=billing></div> </div> Any tricks with the css i should know about?

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  • Software Architecture: Quality Attributes

    Quality is what all software engineers should strive for when building a new system or adding new functionality. Dictonary.com ambiguously defines quality as a grade of excellence. Unfortunately, quality must be defined within the context of a situation in that each engineer must extract quality attributes from a project’s requirements. Because quality is defined by project requirements the meaning of quality is constantly changing base on the project. Software architecture factors that indicate the relevance and effectiveness The relevance and effectiveness of architecture can vary based on the context in which it was conceived and the quality attributes that are required to meet. Typically when evaluating architecture for a specific system regarding relevance and effectiveness the following questions should be asked.   Architectural relevance and effectiveness questions: Does the architectural concept meet the needs of the system for which it was designed? Out of the competing architectures for a system, which one is the most suitable? If we look at the first question regarding meeting the needs of a system for which it was designed. A system that answers yes to this question must meet all of its quality goals. This means that it consistently meets or exceeds performance goals for the system. In addition, the system meets all the other required system attributers based on the systems requirements. The suitability of a system is based on several factors. In order for a project to be suitable the necessary resources must be available to complete the task. Standard Project Resources: Money Trained Staff Time Life cycle factors that affect the system and design The development life cycle used on a project can drastically affect how a system’s architecture is created as well as influence its design. In the case of using the software development life cycle (SDLC) each phase must be completed before the next can begin.  This waterfall approach does not allow for changes in a system’s architecture after that phase is completed. This can lead to major system issues when the architecture for the system is not as optimal because of missed quality attributes. This can occur when a project has poor requirements and makes misguided architectural decisions to name a few examples. Once the architectural phase is complete the concepts established in this phase must move on to the design phase that is bound to use the concepts and guidelines defined in the previous phase regardless of any missing quality attributes needed for the project. If any issues arise during this phase regarding the selected architectural concepts they cannot be corrected during the current project. This directly has an effect on the design of a system because the proper qualities required for the project where not used when the architectural concepts were approved. When this is identified nothing can be done to fix the architectural issues and system design must use the existing architectural concepts regardless of its missing quality properties because the architectural concepts for the project cannot be altered. The decisions made in the design phase then preceded to fall down to the implementation phase where the actual system is coded based on the approved architectural concepts established in the architecture phase regardless of its architectural quality. Conversely projects using more of an iterative or agile methodology to implement a system has more flexibility to correct architectural decisions based on missing quality attributes. This is due to each phase of the SDLC is executed more than once so any issues identified in architecture of a system can be corrected in the next architectural phase. Subsequently the corresponding changes will then be adjusted in the following design phase so that when the project is completed the optimal architectural and design decision are applied to the solution. Architecture factors that indicate functional suitability Systems that have function shortcomings do not have the proper functionality based on the project’s driving quality attributes. What this means in English is that the system does not live up to what is required of it by the stakeholders as identified by the missing quality attributes and requirements. One way to prevent functional shortcomings is to test the project’s architecture, design, and implementation against the project’s driving quality attributes to ensure that none of the attributes were missed in any of the phases. Another way to ensure a system has functional suitability is to certify that all its requirements are fully articulated so that there is no chance for misconceptions or misinterpretations by all stakeholders. This will help prevent any issues regarding interpreting the system requirements during the initial architectural concept phase, design phase and implementation phase. Consider the applicability of other architectural models When considering an architectural model for a project is also important to consider other alternative architectural models to ensure that the model that is selected will meet the systems required functionality and high quality attributes. Recently I can remember talking about a project that I was working on and a coworker suggested a different architectural approach that I had never considered. This new model will allow for the same functionally that is offered by the existing model but will allow for a higher quality project because it fulfills more quality attributes. It is always important to seek alternatives prior to committing to an architectural model. Factors used to identify high-risk components A high risk component can be defined as a component that fulfills 2 or more quality attributes for a system. An example of this can be seen in a web application that utilizes a remote database. One high-risk component in this system is the TCIP component because it allows for HTTP connections to handle by a web server and as well as allows for the server to also connect to a remote database server so that it can import data into the system. This component allows for the assurance of data quality attribute and the accessibility quality attribute because the system is available on the network. If for some reason the TCIP component was to fail the web application would fail on two quality attributes accessibility and data assurance in that the web site is not accessible and data cannot be update as needed. Summary As stated previously, quality is what all software engineers should strive for when building a new system or adding new functionality. The quality of a system can be directly determined by how closely it is implemented when compared to its desired quality attributes. One way to insure a higher quality system is to enforce that all project requirements are fully articulated so that no assumptions or misunderstandings can be made by any of the stakeholders. By doing this a system has a better chance of becoming a high quality system based on its quality attributes

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  • Design patter to keep track UITableView rows correspondance to underlying data in constant time.

    - by DenNukem
    When my model changes I want to animate changes in UITableView by inserting/deleting rows. For that I need to know the ordinal of the given row (so I can construct NSIndexPath), which I find hard to do in better-than-linear time. For example, consider that I have a list of addressbook entries which are manualy sorted by the user, i.e. there is no ordering "key" that represents the sort order. There is also a corresponding UITableView that shows one row per addressbook entry. When UITableView queries the datasource I query the NSMUtableArray populated with my entries and return required data in constant time for each row. However, if there is a change in underlying model I am getting a notification "Joe Smith, id#123 has been removed". Now I have a dilemma. A naive approach would be to scan the array, determine the index at which Joe Smith is and then ask UITableView to remove that precise row from the view, also removing it form the array. However, the scan will take linear time to finish. Now I could have an NSDictionary which allows me to find Joe Smith in constant time, but that doesn't do me a lot of good because I still need to find his ordinal index within the array in order to instruct UITableView to remove that row, which is again a linear search. I could further decide to store each object's ordinal inside the object itself to make it constant, but it will become outdated after first such update as all subsequent index values will have changed due to removal of an object. So what is the correct design pattern to accurately reflect model changes in the UITableView in costant (or at least logarithmic) time?

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  • "Illegal characters in path." Visual Studio WinForm Design View

    - by jacksonakj
    I am putting together a lightweight MVP pattern for a WinForms project. Everything compiles and runs fine. However when I attempt to open the WinForm in design mode in Visual Studio I get a "Illegal characters in path" error. My WinForm is using generics and inheriting from a base Form class. Is there a problem with using generics in a WinForm? Here is the WinForm and base Form class. public partial class TapsForm : MvpForm<TapsPresenter, TapsFormModel>, ITapsView { public TapsForm() { InitializeComponent(); } public TapsForm(TapsPresenter presenter) :base(presenter) { InitializeComponent(); UpdateModel(); } public IList<Taps> Taps { set { gridTaps.DataSource = value; } } private void UpdateModel() { Model.RideId = Int32.Parse(cboRide.Text); Model.Latitude = Double.Parse(txtLatitude.Text); Model.Longitude = Double.Parse(txtLongitude.Text); } } Base form MvpForm: public class MvpForm<TPresenter, TModel> : Form, IView where TPresenter : class, IPresenter where TModel : class, new() { private readonly TPresenter presenter; private TModel model; public MvpForm() { } public MvpForm(TPresenter presenter) { this.presenter = presenter; this.presenter.RegisterView(this); } protected override void OnLoad(EventArgs e) { base.OnLoad(e); if (presenter != null) presenter.IntializeView(); } public TModel Model { get { if (model == null) throw new InvalidOperationException("The Model property is currently null, however it should have been automatically initialized by the presenter. This most likely indicates that no presenter was bound to the control. Check your presenter bindings."); return model; } set { model = value;} } }

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  • How to Set Customer Table with Multiple Phone Numbers? - Relational Database Design

    - by user311509
    CREATE TABLE Phone ( phoneID - PK . . . ); CREATE TABLE PhoneDetail ( phoneDetailID - PK phoneID - FK points to Phone phoneTypeID ... phoneNumber ... . . . ); CREATE TABLE Customer ( customerID - PK firstName phoneID - Unique FK points to Phone . . . ); A customer can have multiple phone numbers e.g. Cell, Work, etc. phoneID in Customer table is unique and points to PhoneID in Phone table. If customer record is deleted, phoneID in Phone table should also be deleted. Do you have any concerns on my design? Is this designed properly? My problem is phoneID in Customer table is a child and if child record is deleted then i can not delete the parent (Phone) record automatically.

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  • Design pattern to keep track UITableView rows correspondance to underlying data in constant time.

    - by DenNukem
    When my model changes I want to animate changes in UITableView by inserting/deleting rows. For that I need to know the ordinal of the given row (so I can construct NSIndexPath), which I find hard to do in better-than-linear time. For example, consider that I have a list of addressbook entries which are manualy sorted by the user, i.e. there is no ordering "key" that represents the sort order. There is also a corresponding UITableView that shows one row per addressbook entry. When UITableView queries the datasource I query the NSMUtableArray populated with my entries and return required data in constant time for each row. However, if there is a change in underlying model I am getting a notification "Joe Smith, id#123 has been removed". Now I have a dilemma. A naive approach would be to scan the array, determine the index at which Joe Smith is and then ask UITableView to remove that precise row from the view, also removing it form the array. However, the scan will take linear time to finish. Now I could have an NSDictionary which allows me to find Joe Smith in constant time, but that doesn't do me a lot of good because I still need to find his ordinal index within the array in order to instruct UITableView to remove that row, which is again a linear search. I could further decide to store each object's ordinal inside the object itself to make it constant, but it will become outdated after first such update as all subsequent index values will have changed due to removal of an object. So what is the correct design pattern to accurately reflect model changes in the UITableView in costant (or at least logarithmic) time?

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  • RESTful design, how to name pages outside CRUD et al?

    - by sscirrus
    Hi all, I'm working on a site that has quite a few pages that fall outside my limited understanding of RESTful design, which is essentially: Create, Read, Update, Delete, Show, List Here's the question: what is a good system for labeling actions/routes when a page doesn't neatly fall into CRUD/show/list? Some of my pages have info about multiple tables at once. I am building a site that gives some customers a 'home base' after they log on. It does NOT give them any information about themselves so it shouldn't be, for example, /customers/show/1. It does have information about companies, but there are other pages on the site that do that differently. What do you do when you have these situations? This 'home-base' is shown to customers and it mainly has info about companies (but not uniquely so). Second case: I have a table called 'Matchings' in between customers and companies. These matchings are accessed in completely different ways on different parts of the site (different layouts, different CSS sheets, different types of users accessing them, etc. They can't ALL be matchings/show. What's the best way to label the others? Thanks very much. =)

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  • How to design Models the correct way: Object-oriented or "Package"-oriented?

    - by ajsie
    I know that in OOP you want every object (from a class) to be a "thing", eg. user, validator etc. I know the basics about MVC, how they different parts interact with each other. However, i wonder if the models in MVC should be designed according to the traditional OOP design, that is to say, should every model be a database/table/row (solution 2)? Or is the intention more like to collect methods that are affecting the same table or a bunch of related tables (solution 1). example for an Address book module in CodeIgniter, where i want be able to "CRUD" a Contact and add/remove it to/from a CRUD-able Contact Group. Models solution 1: bunching all related methods together (not real object, rather a "package") class Contacts extends Model { function create_contact() {) function read_contact() {} function update_contact() {} function delete_contact() {} function add_contact_to_group() {} function delete_contact_from_group() {} function create_group() {} function read_group() {} function update_group() {} function delete_group() {} } Models solution 2: the OOP way (one class per file) class Contact extends Model { private $name = ''; private $id = ''; function create_contact() {) function read_contact() {} function update_contact() {} function delete_contact() {} } class ContactGroup extends Model { private $name = ''; private $id = ''; function add_contact_to_group() {} function delete_contact_from_group() {} function create_group() {} function read_group() {} function update_group() {} function delete_group() {} } i dont know how to think when i want to create the models. and the above examples are my real tasks for creating an Address book. Should i just bunch all functions together in one class. then the class contains different logic (contact and group), so it can not hold properties that are specific for either one of them. the solution 2 works according to the OOP. but i dont know why i should make such a dividing. what would the benefits be to have a Contact object for example. Its surely not a User object, so why should a Contact "live" with its own state (properties and methods). you experienced guys with OOP/MVC, please shed a light on how one should think here in this very concrete task.

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  • Design PDF template and populate data at runtime using java,xml etc..

    - by Samant
    well i have been looking for a java based PDF solutions...we dont have a clean way i guess-still.. all solutions are primitive and kind of workarounds... No easy solution for this requirement - 1. Designing a PDF template using a IDE (eg. Livecycle designer ..which is not free) 2. Then at runtime using java, populate data into this PDF template...either using xml or other datasources... such a simple requirement and NONE has a good "open-source and free" solution yet ! Is anyone aware of any ? I have been searching for since 3-4 years now..for a clean way out... Eclipse BIRT comes close.. but does not handle Barcode elements ..OOB. Jasper - ireport is also good but that tool does not have a table concept and is kind of annoying ! Also barcode support is not good. XSL-FO has not free IDE for design . Looking for a better answer .. got one ?

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  • How to simplify this code or a better design?

    - by Tattat
    I am developing a game, the game have different mode. Easy, Normal, and Difficult. So, I'm thinking about how to store the game mode. My first idea is using number to represent the difficulty. Easy = 0 Normal = 1 Difficult = 2 So, my code will have something like this: switch(gameMode){ case 0: //easy break; case 1: //normal break; case 3: //difficult break; } But I think it have some problems, if I add a new mode, for example, "Extreme", I need to add case 4... ... it seems not a gd design. So, I am thinking making a gameMode object, and different gameMode is sub class of the super class gameMode. The gameMode object is something like this: class GameMode{ int maxEnemyNumber; int maxWeaponNumber; public static GameMode init(){ GameMode gm = GameMode(); gm.maxEnemyNumber = 0; gm.maxWeaponNumber = 0; return gm; } } class EasyMode extends GameMode{ public static GameMode init(){ GameMode gm = super.init(); gm.maxEnemyNumber = 10; gm.maxWeaponNumber = 100; return gm; } } class NormalMode extends GameMode{ public static GameMode init(){ GameMode gm = super.init(); gm.maxEnemyNumber = 20; gm.maxWeaponNumber = 80; return gm; } } But I think it seems too "bulky" to create an object to store gameMode, my "gameMode" only store different variables for game settings.... Is that any simple way to store data only instead of making an Object? thz u.

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  • Java OO design confusion: how to handle actions modified by states modified by actions...

    - by Arvanem
    Hi folks, Given an entity, whose action is potentially modified by states (of the entity and other entities) in turn potentially modified by other actions (of the entity and other entities) , what is the best way to code or design to handle the potential existence of the modifiers? Speaking metaphorically, I am coding a Java application representing a piano. As you know a piano has keys (which, when pressed, emit sound) and pedals (which, when pressed, modify the keys' sounds). My base class structure is as follows: Entity (for keys and pedals) State (this holds each entity's states, e.g. name such as "soft pedal", and boolean "Pressed"), Action (this holds each entity's actions, e.g. play sound when pressed, or modify others sounds). By composition, the Entity class has a copy of each of State and Action inside it. e.g.: public class Entity { State entityState = new State(); Action entityAction = new Action(); Thus I have coded a "C-Sharp" key Entity. When I "press" that entity (set its "Pressed" state to true), its action plays a "C-Sharp" sound and then sets its "Pressed" state to false. At the same time, if the "C-Sharp" key entity is not "tuned", its sound deviates from "C-Sharp". Meanwhile I have coded a "soft pedal" Entity. When that entity is "pressed", no sound plays but its action is to make softer the sound of the "C-Sharp" and other key entities. I have also coded a "sustain pedal" Entity. When that entity is "pressed", no sound plays but its action is to enable reverberation of the sound of the "C-Sharp" and other key entities. Both the "soft" and "sustain pedals" can be pressed at the same time with the result that keys entities become both softened and reverberating. In short, I do not understand how to make this simultaneous series of states and actions modify each other in a sensible OO way. I am wary of coding a massive series of "if" statements or "switches". Thanks in advance for any help or links you can offer.

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