Search Results

Search found 53100 results on 2124 pages for 'o7th web design'.

Page 73/2124 | < Previous Page | 69 70 71 72 73 74 75 76 77 78 79 80  | Next Page >

• Database design for credit based purchases

  - by FreshCode

  I need an elegant way to implement credit-based purchases for an online store with a small variety of products which can be purchased using virtual credit or real currency. Alternatively, products could only be priced in credits. Previous work I have implemented credit-based purchasing before using different product types (eg. Credit, Voucher or Music) with post-order processing to assign purchased credit to users in the form of real currency, which could subsequently be used to discount future orders' charge totals. This worked fairly well as a makeshift solution, but did not succeed in disconnecting the virtual currency from the real currency, which is what I'd like to do, since spending credits is psychologically easier for customers than spending real currency. Design I need guidance on designing the database correctly with support for the simultaneous bulk purchase of credits at a discount along with real currency products. Alternatively, should all products be priced in credits and only credit have a real currency value? Existing Database Design Partial Products table: ProductId Title Type UnitPrice SalePrice Partial Orders table: OrderId UserId (related to Users table, not shown) Status Value Total Partial OrderItems table (similar to CartItems table): OrderItemId OrderId (related to Orders table) ProductId (related to Products table) Quantity UnitPrice SalePrice Prospective UserCredits table: CreditId UserId (related to Users table, not shown) Value (+/- value. Summed over time to determine saldo.) Date I'm using ASP.NET MVC and LINQ-to-SQL on a SQL Server database.

  Read the article

• Database design for sharing photos site?

  - by javaLearner.java

  I am using php and mysql. If I want to do a sharing photos website, whats the best database design for upload and display photos. This is what I have in mind: domain: |_> photos |_> user Logged in user will upload photo in [http://www.domain.com/user/upload.php] The photos are stored in filesystems, and the path-to-photos stored in database. So, in my photos folder would be like: photos/userA/subfolders+photos, photos/userB/subfolders+photos, photos/userC/subfolders+photos etc Public/others people may view his photo in: [http://www.domain.com/photos/user/?photoid=123] where 123 is the photoid, from there, I will query from database to fetch the path and display the image. My questions: Whats the best database design for photo-sharing website (like flickr)? Will there be any problems if I keep creating new folder in "photos" folder. What if hundreds of thousands users registered? Whats the best practices What size of photos should I keep? Currently I only stored thumbnail (100x100) and (max) 1600x1200 px photos. What others things I should take note when developing photos-sharing website?

  Read the article

• Android Multiple Handlers Design Question

  - by Soumya Simanta

  This question is related to an existing question I asked. I though I'll ask a new question instead of replying back to the other question. Cannot "comment" on my previous question because of a word limit. Marc wrote - I've more than one Handlers in an Activity." Why? If you do not want a complicated handleMessage() method, then use post() (on Handler or View) to break the logic up into individual Runnables. Multiple Handlers makes me nervous. I'm new to Android. Is having multiple handlers in a single activity a bad design ? I'm new to Android. My question is - is having multiple handlers in a single activity a bad design ? Here is the sketch of my current implementation. I've a mapActivity that creates a data thread (a UDP socket that listens for data). My first handler is responsible for sending data from the data thread to the activity. On the map I've a bunch of "dynamic" markers that are refreshed frequently. Some of these markers are video markers i.e., if the user clicks a video marker, I add a ViewView that extends a android.opengl.GLSurfaceView to my map activity and display video on this new vide. I use my second handler to send information about the marker that the user tapped on ItemizedOverlay onTap(int index) method. The user can close the video view by tapping on the video view. I use my third handler for this. I would appreciate if people can tell me what's wrong with this approach and suggest better ways to implement this. Thanks.

  Read the article

• Movies recommendation engine conceptual database design

  - by Supyxy

  I am working at an movie recommendations engine and i'm facing a DB design issue. My actual database looks like this: MOVIES [ID,TITLE] KEYWORDS_TABLE [ID,KEY_ID] - where ID is Foreign Key for MOVIES.id and KEY_ID is a key for a text keywords table This is not the entire DB, but i showed here what's important for my problem. I have about 50,000 movies and about 1,3 milion keywords correlations, and basically my algorithm consists in extracting all the who have the same keywords with a given movie, then ordering them by the number of keywords correlations. For example i looked for a movie similar to 'Cast away' and it returned 'Six days and six nights' because it had the most keywords correlations (4 keywords): Island Airplane crash Stranded Pilot The algorithm is based on more factors, but this one is the most important and the most difficult for the approach. Basically what i do now is getting all the movies that have at least one keyword similar to the given movie and then ordering them by other factors which are not important for a moment. There wouldn't be any problem if there weren't so many records, a query lasts in many cases up to 10-20 seconds and some of them return even over 5000 movies. Someone already helped me on here (thanks Mark Byers) with optimizing the query but that's not enough because it takes too longer SELECT DISTINCT M.title FROM keywords_table K1 JOIN keywords_table K2 ON K2.key_id = K1.key_id JOIN movies M ON K2.id = M.id WHERE K1.id = 4 So i thought it would be better if i pre-made those lists with movies recommendations for each movie, but i'm not sure how to design the tables.. whatever is it a good idea or how would you take this approach?

  Read the article

• Simplifying Testing through design considerations while utilizing dependency injection

  - by Adam Driscoll

  We are a few months into a green-field project to rework the Logic and Business layers of our product. By utilizing MEF (dependency injection) we have achieved high levels of code coverage and I believe that we have a pretty solid product. As we have been working through some of the more complex logic I have found it increasingly difficult to unit test. We are utilizing the CompositionContainer to query for types required by these complex algorithms. My unit tests are sometimes difficult to follow due to the lengthy mock object setup process that must take place, just right, to allow for certain circumstances to be verified. My unit tests often take me longer to write than the code that I'm trying to test. I realize this is not only an issue with dependency injection but with design as a whole. Is poor method design or lack of composition to blame for my overly complex tests? I've tried base classing tests, creating commonly used mock objects and ensuring that I utilize the container as much as possible to ease this issue but my tests always end up quite complex and hard to debug. What are some tips that you've seen to keep such tests concise, readable, and effective?

  Read the article

• How do you formulate the Domain Model in Domain Driven Design properly (Bounded Contexts, Domains)?

  - by lko

  Say you have a few applications which deal with a few different Core Domains. The examples are made up and it's hard to put a real example with meaningful data together (concisely). In Domain Driven Design (DDD) when you start looking at Bounded Contexts and Domains/Sub Domains, it says that a Bounded Context is a "phase" in a lifecycle. An example of Context here would be within an ecommerce system. Although you could model this as a single system, it would also warrant splitting into separate Contexts. Each of these areas within the application have their own Ubiquitous Language, their own Model, and a way to talk to other Bounded Contexts to obtain the information they need. The Core, Sub, and Generic Domains are the area of expertise and can be numerous in complex applications. Say there is a long process dealing with an Entity for example a Book in a core domain. Now looking at the Bounded Contexts there can be a number of phases in the books life-cycle. Say outline, creation, correction, publish, sale phases. Now imagine a second core domain, perhaps a store domain. The publisher has its own branch of stores to sell books. The store can have a number of Bounded Contexts (life-cycle phases) for example a "Stock" or "Inventory" context. In the first domain there is probably a Book database table with basically just an ID to track the different book Entities in the different life-cycles. Now suppose you have 10+ supporting domains e.g. Users, Catalogs, Inventory, .. (hard to think of relevant examples). For example a DomainModel for the Book Outline phase, the Creation phase, Correction phase, Publish phase, Sale phase. Then for the Store core domain it probably has a number of life-cycle phases. public class BookId : Entity { public long Id { get; set; } } In the creation phase (Bounded Context) the book could be a simple class. public class Book : BookId { public string Title { get; set; } public List<string> Chapters { get; set; } //... } Whereas in the publish phase (Bounded Context) it would have all the text, release date etc. public class Book : BookId { public DateTime ReleaseDate { get; set; } //... } The immediate benefit I can see in separating by "life-cycle phase" is that it's a great way to separate business logic so there aren't mammoth all-encompassing Entities nor Domain Services. A problem I have is figuring out how to concretely define the rules to the physical layout of the Domain Model. A. Does the Domain Model get "modeled" so there are as many bounded contexts (separate projects etc.) as there are life-cycle phases across the core domains in a complex application? Edit: Answer to A. Yes, according to the answer by Alexey Zimarev there should be an entire "Domain" for each bounded context. B. Is the Domain Model typically arranged by Bounded Contexts (or Domains, or both)? Edit: Answer to B. Each Bounded Context should have its own complete "Domain" (Service/Entities/VO's/Repositories) C. Does it mean there can easily be 10's of "segregated" Domain Models and multiple projects can use it (the Entities/Value Objects)? Edit: Answer to C. There is a complete "Domain" for each Bounded Context and the Domain Model (Entity/VO layer/project) isn't "used" by the other Bounded Contexts directly, only via chosen paths (i.e. via Domain Events). The part that I am trying to figure out is how the Domain Model is actually implemented once you start to figure out your Bounded Contexts and Core/Sub Domains, particularly in complex applications. The goal is to establish the definitions which can help to separate Entities between the Bounded Contexts and Domains.

  Read the article

• Which Table Should be Master and Child in Database Design

  - by Jason

  I am quickly learning the ins and outs of database design (something that, as of a week ago, was new to me), but I am running across some questions that don't seem immediately obvious, so I was hoping to get some clarification. The question I have right is about foreign keys. As part of my design, I have a Company table. Originally, I had included address information directly within the table, but, as I was hoping to achieve 3NF, I broke out the address information into its own table, Address. In order to maintain data integrity, I created a row in Company called "addressId" as an INT and the Address table has a corresponding addressId as its primary key. What I'm a little bit confused about (or what I want to make sure I'm doing correctly) is determining which table should be the master (referenced) table and which should be the child (referencing) table. When I originally set this up, I made the Address table the master and the Company the child. However, I now believe this is wrong due to the fact that there should be only one address per Company and, if a Company row is deleted, I would want the corresponding Address to be removed as well (CASCADE deletion). I may be approaching this completely wrong, so I would appreciate any good rules of thumb on how to best think about the relationship between tables when using foreign keys. Thanks!

  Read the article

• Design of std::ifstream class

  - by Nawaz

  Those of us who have seen the beauty of STL try to use it as much as possible, and also encourage others to use it wherever we see them using raw pointers and arrays. Scott Meyers have written a whole book on STL, with title Effective STL. Yet what happened to the developers of ifstream that they preferred char* over std::string. I wonder why the first parameter of ifstream::open() is of type const char*, instead of const std::string &. Please have a look at it's signature: void open(const char * filename, ios_base::openmode mode = ios_base::in ); Why this? Why not this: void open(const string & filename, ios_base::openmode mode = ios_base::in ); Is this a serious mistake with the design? Or this design is deliberate? What could be the reason? I don't see any reason why they have preferred char* over std::string. Note we could still pass char* to the latter function that takes std::string. That's not a problem! By the way, I'm aware that ifstream is a typedef, so no comment on my title.:P. It looks short that is why I used it. The actual class template is : template<class _Elem,class _Traits> class basic_ifstream;

  Read the article

• how to design a schema where the columns of a table are not fixed

  - by hIpPy

  I am trying to design a schema where the columns of a table are not fixed. Ex: I have an Employee table where the columns of the table are not fixed and vary (attributes of Employee are not fixed and vary). Nullable columns in the Employee table itself i.e. no normalization Instead of adding nullable columns, separate those columns out in their individual tables ex: if Address is a column to be added then create table Address[EmployeeId, AddressValue]. Create tables ExtensionColumnName [EmployeeId, ColumnName] and ExtensionColumnValue [EmployeeId, ColumnValue]. ExtensionColumnName would have ColumnName as "Address" and ExtensionColumnValue would have ColumnValue as address value. Employee table EmployeeId Name ExtensionColumnName table ColumnNameId EmployeeId ColumnName ExtensionColumnValue table EmployeeId ColumnNameId ColumnValue There is a drawback is the first two ways as the schema changes with every new attribute. Note that adding a new attribute is frequent. I am not sure if this is the good or bad design. If someone had a similar decision to make, please give an insight on things like foreign keys / data integrity, indexing, performance, reporting etc.

  Read the article

• Node & Redis: Crucial Design Issues in Production Mode

  - by Ali

  This question is a hybrid one, being both technical and system design related. I'm developing the backend of an application that will handle approx. 4K request per second. We are using Node.js being super fast and in terms of our database struction we are using MongoDB, with Redis being a layer between Node and MongoDB handling volatile operations. I'm quite stressed because we are expecting concurrent requests that we need to handle carefully and we are quite close to launch. However I do not believe I've applied the correct approach on redis. I have a class Student, and they constantly change stages(such as 'active', 'doing homework','in lesson' etc. Thus I created a Redis DB for each state. (1 for being 'active', 2 for being 'doing homework'). Above I have the structure of the 'active' students table; xa5p - JSON stringified object #1 pQrW - JSON stringified object #2 active_student_table - {{studentId:'xa5p'}, {studentId:'pQrW'}} Since there is no 'select all keys method' in Redis, I've been suggested to use a set such that when I run command 'smembers' I receive the keys and later on do 'get' for each id in order to find a specific user (lets say that age older than 15). I've been also suggested that in fact I used never use keys in production mode. My question is, no matter how 'conceptual' it is, what specific things I should avoid doing in Node & Redis in production stage?. Are they any issues related to my design? Students must be objects and I sure can list them in a list but I haven't done yet. Is it that crucial in production stage?

  Read the article

• Are Tuples a poor design decision in C#?

  - by Jason Webb

  With the addition of the Tuple class in .net 4, I have been trying to decide if using them in my design is a bad choice or not. The way I see it, a Tuple is a shortcut to writing a result class (I am sure there are other uses too). So this: public class ResultType { public string StringValue { get; set; } public int IntValue { get; set; } } public ResultType GetAClassedValue() { //..Do Some Stuff ResultType result = new ResultType { StringValue = "A String", IntValue = 2 }; return result; } Is equivalent to this: public Tuple<string, int> GetATupledValue() { //...Do Some stuff Tuple<string, int> result = new Tuple<string, int>("A String", 2); return result; } So setting aside the possibility that I am missing the point of Tuples, is the example with a Tuple a bad design choice? To me it seems like less clutter, but not as self documenting and clean. Meaning that with the type ResultType, it is very clear later on what each part of the class means but you have extra code to maintain. With the Tuple<string, int> you will need to look up and figure out what each Item represents, but you write and maintain less code. Any experience you have had with this choice would be greatly appreciated.

  Read the article

• Compromising design & code quality to integrate with existing modules

  - by filip-fku

  Greetings! I inherited a C#.NET application I have been extending and improving for a while now. Overall it was obviously a rush-job (or whoever wrote it was seemingly less competent than myself). The app pulls some data from an embedded device & displays and manipulates it. At the core is a communications thread in the main application form which executes a 600+ lines of code method which calls functions all over the place, implementing a state machine - lots of if-state-then-do type code. Interaction with the device is done by setting the state/mode globally and letting the thread do it's thing. (This is just one example of the badness of the code - overall it is not very OO-like, it reminds of the style of embedded C code the device firmware is written in). My problem is that this piece of code is central to the application. The software, communications protocol or device firmware are not documented at all. Obviously to carry on with my work I have to interact with this code. What I would like some guidance on, is whether it is worth scrapping this code & trying to piece together something more reasonable from the information I can reverse engineer? I can't decide! The reason I don't want to refactor is because the code already works, and changing it will surely be a long, laborious and unpleasant task. On the flip side, not refactoring means I have to sometimes compromise the design of other modules so that I may call my code from this state machine! I've heard of "If it ain't broke don't fix it!", so I am wondering if it should apply when "it" is influencing the design of future code! Any advice would be appreciated! Thanks!

  Read the article

• Importing data from third party datasource (open architecture design )

  - by mare

  How would you design an application (classes, interfaces in class library) in .NET when we have a fixed database design on our side and we need to support imports of data from third party data sources, which will most likely be in XML? For instance, let us say we have a Products table in our DB which has columns Id Title Description TaxLevel Price and on the other side we have for instance Products: ProductId ProdTitle Text BasicPrice Quantity. Currently I do it like this: Have the third party XML convert to classes and XSD's and then deserialize its contents into strong typed objects (what we get as a result of this process is classes like ThirdPartyProduct, ThirdPartyClassification, etc.). Then I have methods like this: InsertProduct(ThirdPartyProduct newproduct) I do not use interfaces at the moment but I would like them to. What I would like is implement something like public class Contoso_ProductSynchronization : ProductSynchronization InsertProduct(ContosoProduct p) where ProductSynchronization will be an interface or abstract class. There will most likely be many implementations of ProductSynchronization. I cannot hardcode the types - classes like ContosoProduct, NorthwindProduct might be created from the third party XML's (so preferably I would continue to use deserialization). Hopefully someone will understand what I'm trying to explain here. Just imagine you are the seller and you have numerous providers and each one uses their own proprietary XML format. I don't mind the development, which will of course be needed everytime new format appears, because it will only require 10-20 methods to be implemented, I just want the architecture to be open and support that.

  Read the article

• In an online questionnaire, what is a best way to design a database for keeping track of users all attempts?

  - by user1990525

  We have a web app where users can take online exams. Exam admin will create a questionnaire. A questionnaire can have many Questions. Each question is a multiple choice question (MCQ). Lets say an admin creates a questionnaire with 10 questions. Users attempt those questions. Now, unlike real exams users can attempt single questionnaire multiple times. And we have to keep track of his all attempts. e.g. User_id Questionnaire_id question_id answer attempt_date attempt_no 1 1 1 a 1 June 2013 1 1 1 2 b 1 June 2013 1 1 1 1 c 2 June 2013 2 1 1 2 d 2 June 2013 2 Now it can also happen that after user has attempted same questionnare twice, admin can delete a question from same questionnaire, but users attempt history should still have reference to that so that user can see his that question in his attempt history in spite of admin deleting that question. If user now attempts this changed questionnaire he should see only 1 question. User_id Questionnaire_id question_id answer attempt_date attempt_no 1 1 1 a 3 June 2013 3 Also, after this user modified some part of question, users attempt history should show question before modification while any new attempt should show modified question. How do we manage this at the database level? My first gut feeling was that, For deletes, do not do physical delete, just make a question inactive so that history can still keep track of users attempt. For modifications, create versions for questions and each new attempt refres to latest version of each question and history keeping reference to version of question at attempt time.

  Read the article

• How to make this design closer to proper DDD?

  - by Seralize

  I've read about DDD for days now and need help with this sample design. All the rules of DDD make me very confused to how I'm supposed to build anything at all when domain objects are not allowed to show methods to the application layer; where else to orchestrate behaviour? Repositories are not allowed to be injected into entities and entities themselves must thus work on state. Then an entity needs to know something else from the domain, but other entity objects are not allowed to be injected either? Some of these things makes sense to me but some don't. I've yet to find good examples of how to build a whole feature as every example is about Orders and Products, repeating the other examples over and over. I learn best by reading examples and have tried to build a feature using the information I've gained about DDD this far. I need your help to point out what I do wrong and how to fix it, most preferably with code as "I would not recomment doing X and Y" is very hard to understand in a context where everything is just vaguely defined already. If I can't inject an entity into another it would be easier to see how to do it properly. In my example there are users and moderators. A moderator can ban users, but with a business rule: only 3 per day. I did an attempt at setting up a class diagram to show the relationships (code below): interface iUser { public function getUserId(); public function getUsername(); } class User implements iUser { protected $_id; protected $_username; public function __construct(UserId $user_id, Username $username) { $this->_id = $user_id; $this->_username = $username; } public function getUserId() { return $this->_id; } public function getUsername() { return $this->_username; } } class Moderator extends User { protected $_ban_count; protected $_last_ban_date; public function __construct(UserBanCount $ban_count, SimpleDate $last_ban_date) { $this->_ban_count = $ban_count; $this->_last_ban_date = $last_ban_date; } public function banUser(iUser &$user, iBannedUser &$banned_user) { if (! $this->_isAllowedToBan()) { throw new DomainException('You are not allowed to ban more users today.'); } if (date('d.m.Y') != $this->_last_ban_date->getValue()) { $this->_ban_count = 0; } $this->_ban_count++; $date_banned = date('d.m.Y'); $expiration_date = date('d.m.Y', strtotime('+1 week')); $banned_user->add($user->getUserId(), new SimpleDate($date_banned), new SimpleDate($expiration_date)); } protected function _isAllowedToBan() { if ($this->_ban_count >= 3 AND date('d.m.Y') == $this->_last_ban_date->getValue()) { return false; } return true; } } interface iBannedUser { public function add(UserId $user_id, SimpleDate $date_banned, SimpleDate $expiration_date); public function remove(); } class BannedUser implements iBannedUser { protected $_user_id; protected $_date_banned; protected $_expiration_date; public function __construct(UserId $user_id, SimpleDate $date_banned, SimpleDate $expiration_date) { $this->_user_id = $user_id; $this->_date_banned = $date_banned; $this->_expiration_date = $expiration_date; } public function add(UserId $user_id, SimpleDate $date_banned, SimpleDate $expiration_date) { $this->_user_id = $user_id; $this->_date_banned = $date_banned; $this->_expiration_date = $expiration_date; } public function remove() { $this->_user_id = ''; $this->_date_banned = ''; $this->_expiration_date = ''; } } // Gathers objects $user_repo = new UserRepository(); $evil_user = $user_repo->findById(123); $moderator_repo = new ModeratorRepository(); $moderator = $moderator_repo->findById(1337); $banned_user_factory = new BannedUserFactory(); $banned_user = $banned_user_factory->build(); // Performs ban $moderator->banUser($evil_user, $banned_user); // Saves objects to database $user_repo->store($evil_user); $moderator_repo->store($moderator); $banned_user_repo = new BannedUserRepository(); $banned_user_repo->store($banned_user); Should the User entitity have a 'is_banned' field which can be checked with $user->isBanned();? How to remove a ban? I have no idea.

  Read the article

• Help with Design for Vacation Tracking System (C#/.NET/Access/WebServices/SOA/Excel) [closed]

  - by Aaronaught

  I have been tasked with developing a system for tracking our company's paid time-off (vacation, sick days, etc.) At the moment we are using an Excel spreadsheet on a shared network drive, and it works pretty well, but we are concerned that we won't be able to "trust" employees forever and sometimes we run into locking issues when two people try to open the spreadsheet at once. So we are trying to build something a little more robust. I would like some input on this design in terms of maintainability, scalability, extensibility, etc. It's a pretty simple workflow we need to represent right now: I started with a basic MS Access schema like this: Employees (EmpID int, EmpName varchar(50), AllowedDays int) Vacations (VacationID int, EmpID int, BeginDate datetime, EndDate datetime) But we don't want to spend a lot of time building a schema and database like this and have to change it later, so I think I am going to go with something that will be easier to expand through configuration. Right now the vacation table has this schema: Vacations (VacationID int, PropName varchar(50), PropValue varchar(50)) And the table will be populated with data like this: VacationID | PropName | PropValue -----------+--------------+------------------ 1 | EmpID | 4 1 | EmpName | James Jones 1 | Reason | Vacation 1 | BeginDate | 2/24/2010 1 | EndDate | 2/30/2010 1 | Destination | Spectate Swamp 2 | ... | ... I think this is a pretty good, extensible design, we can easily add new properties to the vacation like the destination or maybe approval status, etc. I wasn't too sure how to go about managing the database of valid properties, I thought of putting them in a separate PropNames table but it gets complicated to manage all the different data types and people say that you shouldn't put CLR type names into a SQL database, so I decided to use XML instead, here is the schema: <VacationProperties> <PropertyNames>EmpID,EmpName,Reason,BeginDate,EndDate,Destination</PropertyNames> <PropertyTypes>System.Int32,System.String,System.String,System.DateTime,System.DateTime,System.String</PropertyTypes> <PropertiesRequired>true,true,false,true,true,false</PropertiesRequired> </VacationProperties> I might need more fields than that, I'm not completely sure. I'm parsing the XML like this (would like some feedback on the parsing code): string xml = File.ReadAllText("properties.xml"); Match m = Regex.Match(xml, "<(PropertyNames)>(.*?)</PropertyNames>"; string[] pn = m.Value.Split(','); // do the same for PropertyTypes, PropertiesRequired Then I use the following code to persist configuration changes to the database: string sql = "DROP TABLE VacationProperties"; sql = sql + " CREATE TABLE VacationProperties "; sql = sql + "(PropertyName varchar(100), PropertyType varchar(100) "; sql = sql + "IsRequired varchar(100))"; for (int i = 0; i < pn.Length; i++) { sql = sql + " INSERT VacationProperties VALUES (" + pn[i] + "," + pt[i] + "," + pv[i] + ")"; } // GlobalConnection is a singleton new SqlCommand(sql, GlobalConnection.Instance).ExecuteReader(); So far so good, but after a few days of this I then realized that a lot of this was just a more specific kind of a generic workflow which could be further abstracted, and instead of writing all of this boilerplate plumbing code I could just come up with a workflow and plug it into a workflow engine like Windows Workflow Foundation and have the users configure it: In order to support routing these configurations throw the workflow system, it seemed natural to implement generic XML Web Services for this instead of just using an XML file as above. I've used this code to implement the Web Services: public class VacationConfigurationService : WebService { [WebMethod] public void UpdateConfiguration(string xml) { // Above code goes here } } Which was pretty easy, although I'm still working on a way to validate that XML against some kind of schema as there's no error-checking yet. I also created a few different services for other operations like VacationSubmissionService, VacationReportService, VacationDataService, VacationAuthenticationService, etc. The whole Service Oriented Architecture looks like this: And because the workflow itself might change, I have been working on a way to integrate the WF workflow system with MS Visio, which everybody at the office already knows how to use so they could make changes pretty easily. We have a diagram that looks like the following (it's kind of hard to read but the main items are Activities, Authenticators, Validators, Transformers, Processors, and Data Connections, they're all analogous to the services in the SOA diagram above). The requirements for this system are: (Note - I don't control these, they were given to me by management) Main workflow must interface with Excel spreadsheet, probably through VBA macros (to ease the transition to the new system) Alerts should integrate with MS Outlook, Lotus Notes, and SMS (text messages). We also want to interface it with the company Voice Mail system but that is not a "hard" requirement. Performance requirements: Must handle 250,000 Transactions Per Second Should be able to handle up to 20,000 employees (right now we have 3) 99.99% uptime ("four nines") expected Must be secure against outside hacking, but users cannot be required to enter a username/password. Platforms: Must support Windows XP/Vista/7, Linux, iPhone, Blackberry, DOS 2.0, VAX, IRIX, PDP-11, Apple IIc. Time to complete: 6 to 8 weeks. My questions are: Is this a good design for the system so far? Am I using all of the recommended best practices for these technologies? How do I integrate the Visio diagram above with the Windows Workflow Foundation to call the ConfigurationService and persist workflow changes? Am I missing any important components? Will this be extensible enough to support any scenario via end-user configuration? Will the system scale to the above performance requirements? Will we need any expensive hardware to run it? Are there any "gotchas" I should know about with respect to cross-platform compatibility? For example would it be difficult to convert this to an iPhone app? How long would you expect this to take? (We've dedicated 1 week for testing so I'm thinking maybe 5 weeks?) Many thanks for your advices, Aaron

  Read the article

• Design for Vacation Tracking System

  - by Aaronaught

  I have been tasked with developing a system for tracking our company's paid time-off (vacation, sick days, etc.) At the moment we are using an Excel spreadsheet on a shared network drive, and it works pretty well, but we are concerned that we won't be able to "trust" employees forever and sometimes we run into locking issues when two people try to open the spreadsheet at once. So we are trying to build something a little more robust. I would like some input on this design in terms of maintainability, scalability, extensibility, etc. It's a pretty simple workflow we need to represent right now: I started with a basic MS Access schema like this: Employees (EmpID int, EmpName varchar(50), AllowedDays int) Vacations (VacationID int, EmpID int, BeginDate datetime, EndDate datetime) But we don't want to spend a lot of time building a schema and database like this and have to change it later, so I think I am going to go with something that will be easier to expand through configuration. Right now the vacation table has this schema: Vacations (VacationID int, PropName varchar(50), PropValue varchar(50)) And the table will be populated with data like this: VacationID | PropName | PropValue -----------+--------------+------------------ 1 | EmpID | 4 1 | EmpName | James Jones 1 | Reason | Vacation 1 | BeginDate | 2/24/2010 1 | EndDate | 2/30/2010 1 | Destination | Spectate Swamp 2 | ... | ... I think this is a pretty good, extensible design, we can easily add new properties to the vacation like the destination or maybe approval status, etc. I wasn't too sure how to go about managing the database of valid properties, I thought of putting them in a separate PropNames table but it gets complicated to manage all the different data types and people say that you shouldn't put CLR type names into a SQL database, so I decided to use XML instead, here is the schema: <VacationProperties> <PropertyNames>EmpID,EmpName,Reason,BeginDate,EndDate,Destination</PropertyNames> <PropertyTypes>System.Int32,System.String,System.String,System.DateTime,System.DateTime,System.String</PropertyTypes> <PropertiesRequired>true,true,false,true,true,false</PropertiesRequired> </VacationProperties> I might need more fields than that, I'm not completely sure. I'm parsing the XML like this (would like some feedback on the parsing code): string xml = File.ReadAllText("properties.xml"); Match m = Regex.Match(xml, "<(PropertyNames)>(.*?)</PropertyNames>"; string[] pn = m.Value.Split(','); // do the same for PropertyTypes, PropertiesRequired Then I use the following code to persist configuration changes to the database: string sql = "DROP TABLE VacationProperties"; sql = sql + " CREATE TABLE VacationProperties "; sql = sql + "(PropertyName varchar(100), PropertyType varchar(100) "; sql = sql + "IsRequired varchar(100))"; for (int i = 0; i < pn.Length; i++) { sql = sql + " INSERT VacationProperties VALUES (" + pn[i] + "," + pt[i] + "," + pv[i] + ")"; } // GlobalConnection is a singleton new SqlCommand(sql, GlobalConnection.Instance).ExecuteReader(); So far so good, but after a few days of this I then realized that a lot of this was just a more specific kind of a generic workflow which could be further abstracted, and instead of writing all of this boilerplate plumbing code I could just come up with a workflow and plug it into a workflow engine like Windows Workflow Foundation and have the users configure it: In order to support routing these configurations throw the workflow system, it seemed natural to implement generic XML Web Services for this instead of just using an XML file as above. I've used this code to implement the Web Services: public class VacationConfigurationService : WebService { [WebMethod] public void UpdateConfiguration(string xml) { // Above code goes here } } Which was pretty easy, although I'm still working on a way to validate that XML against some kind of schema as there's no error-checking yet. I also created a few different services for other operations like VacationSubmissionService, VacationReportService, VacationDataService, VacationAuthenticationService, etc. The whole Service Oriented Architecture looks like this: And because the workflow itself might change, I have been working on a way to integrate the WF workflow system with MS Visio, which everybody at the office already knows how to use so they could make changes pretty easily. We have a diagram that looks like the following (it's kind of hard to read but the main items are Activities, Authenticators, Validators, Transformers, Processors, and Data Connections, they're all analogous to the services in the SOA diagram above). The requirements for this system are: (Note - I don't control these, they were given to me by management) Main workflow must interface with Excel spreadsheet, probably through VBA macros (to ease the transition to the new system) Alerts should integrate with MS Outlook, Lotus Notes, and SMS (text messages). We also want to interface it with the company Voice Mail system but that is not a "hard" requirement. Performance requirements: Must handle 250,000 Transactions Per Second Should be able to handle up to 20,000 employees (right now we have 3) 99.99% uptime ("four nines") expected Must be secure against outside hacking, but users cannot be required to enter a username/password. Platforms: Must support Windows XP/Vista/7, Linux, iPhone, Blackberry, DOS 2.0, VAX, IRIX, PDP-11, Apple IIc. Time to complete: 6 to 8 weeks. My questions are: Is this a good design for the system so far? Am I using all of the recommended best practices for these technologies? How do I integrate the Visio diagram above with the Windows Workflow Foundation to call the ConfigurationService and persist workflow changes? Am I missing any important components? Will this be extensible enough to support any scenario via end-user configuration? Will the system scale to the above performance requirements? Will we need any expensive hardware to run it? Are there any "gotchas" I should know about with respect to cross-platform compatibility? For example would it be difficult to convert this to an iPhone app? How long would you expect this to take? (We've dedicated 1 week for testing so I'm thinking maybe 5 weeks?)

  Read the article

• Observer pattern and violation of Single Principality Rule

  - by Devil Jin

  I have an applet which repaints itself once the text has changed Design 1: //MyApplet.java public class MyApplet extends Applet implements Listener{ private DynamicText text = null; public void init(){ text = new DynamicText("Welcome"); } public void paint(Graphics g){ g.drawString(text.getText(), 50, 30); } //implement Listener update() method public void update(){ repaint(); } } //DynamicText.java public class DynamicText implements Publisher{ // implements Publisher interface methods //notify listeners whenever text changes } Isn't this a violation of Single Responsibility Principle where my Applet not only acts as Applet but also has to do Listener job. Same way DynamicText class not only generates the dynamic text but updates the registered listeners. Design 2: //MyApplet.java public class MyApplet extends Applet{ private AppletListener appLstnr = null; public void init(){ appLstnr = new AppletListener(this); // applet stuff } } // AppletListener.java public class AppletListener implements Listener{ private Applet applet = null; public AppletListener(Applet applet){ this.applet = applet; } public void update(){ this.applet.repaint(); } } // DynamicText public class DynamicText{ private TextPublisher textPblshr = null; public DynamicText(TextPublisher txtPblshr){ this.textPblshr = txtPblshr; } // call textPblshr.notifyListeners whenever text changes } public class TextPublisher implments Publisher{ // implements publisher interface methods } Q1. Is design 1 a SPR violation? Q2. Is composition a better choice here to remove SPR violation as in design 2.

  Read the article

• Which book should I choose?

  - by sebastianlarsson

  Hi guys, I'm looking for a good read on object oriented design. The two books I'm currently looking Head First Design Patterns and Head First Object object-oriented analysis & design. They seem very similar when looking at the contents and browsing through available sample text. Which one would be the best choice? About myself: I have a bachelor in computer science and I am currently studying Msc. Software Quality Engineering (read Software Engineering with focus on Quality). I am already confident in object-oriented design and have a lot of programming courses in my backpack. I have done games in c++, courses in advanced java programming (I am SCJP certified), but my preferred language is C#. I have also worked with Java for the last 7 months while studying. I am currently also studying for certificates in C# (apart from my usual studies). So I believe I have the prerequisites of actually understanding the contents of both books. Reason: I just want to be better and keep evolving as a programmer. I think it is fun. I believe Bert Bates and Kathy Sierra are involved in both these books and I have previously read their SCJP preparation book in java. I really do enjoy their style of writing. Other books which I am considering are: Clean Code: A Handbook Of Agile Software Craftsmanship Thx in advance Sebastian

  Read the article

• Observer pattern and violation of Single Responsibility Principle

  - by Devil Jin

  I have an applet which repaints itself once the text has changed Design 1: //MyApplet.java public class MyApplet extends Applet implements Listener{ private DynamicText text = null; public void init(){ text = new DynamicText("Welcome"); } public void paint(Graphics g){ g.drawString(text.getText(), 50, 30); } //implement Listener update() method public void update(){ repaint(); } } //DynamicText.java public class DynamicText implements Publisher{ // implements Publisher interface methods //notify listeners whenever text changes } Isn't this a violation of Single Responsibility Principle where my Applet not only acts as Applet but also has to do Listener job. Same way DynamicText class not only generates the dynamic text but updates the registered listeners. Design 2: //MyApplet.java public class MyApplet extends Applet{ private AppletListener appLstnr = null; public void init(){ appLstnr = new AppletListener(this); // applet stuff } } // AppletListener.java public class AppletListener implements Listener{ private Applet applet = null; public AppletListener(Applet applet){ this.applet = applet; } public void update(){ this.applet.repaint(); } } // DynamicText public class DynamicText{ private TextPublisher textPblshr = null; public DynamicText(TextPublisher txtPblshr){ this.textPblshr = txtPblshr; } // call textPblshr.notifyListeners whenever text changes } public class TextPublisher implments Publisher{ // implements publisher interface methods } Q1. Is design 1 a SPR violation? Q2. Is composition a better choice here to remove SPR violation as in design 2.

  Read the article

• Configure Forms based authentication in SharePoint 2010

  - by sreejukg

    Configuring form authentication is a straight forward task in SharePoint. Mostly public facing websites built on SharePoint requires form based authentication. Recently, one of the WCM implementation where I was included in the project team required registration system. Any internet user can register to the site and the site offering them some membership specific functionalities once the user logged in. Since the registration open for all, I don’t want to store all those users in Active Directory. I have decided to use Forms based authentication for those users. This is a typical scenario of form authentication in SharePoint implementation. To implement form authentication you require the following A data store where you are storing the users – technically this can be active directory, SQL server database, LDAP etc. Form authentication will redirect the user to the login page, if the request is not authenticated. In the login page, there will be controls that validate the user inputs against the configured data store. In this article, I am going to use SQL server database with ASP.Net membership API’s to configure form based authentication in SharePoint 2010. This article assumes that you have SQL membership database available. I already configured the membership and roles database using aspnet_regsql command. If you want to know how to configure membership database using aspnet_regsql command, read the below blog post. http://weblogs.asp.net/sreejukg/archive/2011/06/16/usage-of-aspnet-regsql-exe-in-asp-net-4.aspx The snapshot of the database after implementing membership and role manager is as follows. I have used the database name “aspnetdb_claim”. Make sure you have created the database and make sure your database contains tables and stored procedures for membership. Create a web application with claims based authentication. This article assumes you already created a web application using claims based authentication. If you want to enable forms based authentication in SharePoint 2010, you must enable claims based authentication. Read this post for creating a web application using claims based authentication. http://weblogs.asp.net/sreejukg/archive/2011/06/15/create-a-web-application-in-sharepoint-2010-using-claims-based-authentication.aspx  You make sure, you have selected enable form authentication, and then selected Membership provider and Role manager name. To make sure you are done with the configuration, navigate to central administration website, from central administration, navigate to the Web Applications page, select the web application and click on icon, you will see the authentication providers for the current web application. Go to the section Claims authentication types, and make sure you have enabled forms based authentication. As mentioned in the snapshot, I have named the membership provider as SPFormAuthMembership and role manager as SPFormAuthRoleManager. You can choose your own names as you need. Modify the configuration files(Web.Config) to enable form authentication There are three applications that needs to be configured to support form authentication. The following are those applications. Central Administration If you want to assign permissions to web application using the credentials from form authentication, you need to update Central Administration configuration. If you do not want to access form authentication credentials from Central Administration, just leave this step.  STS service application Security Token service is the service application that issues security token when users are logging in. You need to modify the configuration of STS application to make sure users are able to login. To find the STS application, follow the following steps Go to the IIS Manager Expand the sites Node, you will see SharePoint Web Services Expand SharePoint Web Services, you can see SecurityTokenServiceApplication Right click SecuritytokenServiceApplication and click explore, it will open the corresponding file system. By default, the path for STS is C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\WebServices\SecurityToken You need to modify the configuration file available in the mentioned location. The web application that needs to be enabled with form authentication. You need to modify the configuration of your web application to make sure your web application identifies users from the form authentication.   Based on the above, I am going to modify the web configuration. At end of each step, I have mentioned the expected output. I recommend you to go step by step and after each step, make sure the configuration changes are working as expected. If you do everything all together, and test your application at the end, you may face difficulties in troubleshooting the configuration errors. Modifications for Central Administration Web.Config Open the web.config for the Central administration in a text editor. I always prefer Visual Studio, for editing web.config. In most cases, the path of the web.config for the central administration website is as follows C:\inetpub\wwwroot\wss\VirtualDirectories\<port number> Make sure you keep a backup copy of the web.config, before editing it. Let me summarize what we are going to do with Central Administration web.config. First I am going to add a connection string that points to the form authentication database, that I created as mentioned in previous steps. Then I need to add a membership provider and a role manager with the corresponding connectionstring. Then I need to update the peoplepickerwildcards section to make sure the users are appearing in search results. By default there is no connection string available in the web.config of Central Administration. Add a connection string just after the configsections element. The below is the connection string I have used all over the article. <add name="FormAuthConnString" connectionString="Initial Catalog=yourdatabasename;data source=databaseservername;Integrated Security=SSPI;" /> Once you added the connection string, the web.config look similar to Now add membership provider to the code. In web.config for CA, there will be <membership> tag, search for it. You will find membership and role manager under the <system.web> element. Under the membership providers section add the below code… <add name="SPFormAuthMembership" type="System.Web.Security.SqlMembershipProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" applicationName="FormAuthApplication" connectionStringName="FormAuthConnString" /> After adding memberhip element, see the snapshot of the web.config. Now you need to add role manager element to the web.config. Insider providers element under rolemanager, add the below code. <add name="SPFormAuthRoleManager" type="System.Web.Security.SqlRoleProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" applicationName="FormAuthApplication" connectionStringName="FormAuthConnString" /> After adding, your role manager will look similar to the following. As a last step, you need to update the people picker wildcard element in web.config, so that the users from your membership provider are available for browsing in Central Administration. Search for PeoplePickerWildcards in the web.config, add the following inside the <PeoplePickerWildcards> tag. <add key="SPFormAuthMembership" value="%" /> After adding this element, your web.config will look like After completing these steps, you can browse the users available in the SQL server database from central administration website. Go to the site collection administrator’s page from central administration. Select the site collection you have created for form authentication. Click on the people picker icon, choose Forms Auth and click on the search icon, you will see the users listed from the SQL server database. Once you complete these steps, make sure the users are available for browsing from central administration website. If you are unable to find the users, there must be some errors in the configuration, check windows event logs to find related errors and fix them. Change the web.config for STS application Open the web.config for STS application in text editor. By default, STS web.config does not have system.Web or connectionstrings section. Just after the System.Webserver element, add the following code. <connectionStrings> <add name="FormAuthConnString" connectionString="Initial Catalog=aspnetdb_claim;data source=sp2010_db;Integrated Security=SSPI;" /> </connectionStrings> <system.web> <roleManager enabled="true" cacheRolesInCookie="false" cookieName=".ASPXROLES" cookieTimeout="30" cookiePath="/" cookieRequireSSL="false" cookieSlidingExpiration="true" cookieProtection="All" createPersistentCookie="false" maxCachedResults="25"> <providers> <add name="SPFormAuthRoleManager" type="System.Web.Security.SqlRoleProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" applicationName="FormAuthApplication" connectionStringName="FormAuthConnString" /> </providers> </roleManager> <membership userIsOnlineTimeWindow="15" hashAlgorithmType=""> <providers> <add name="SPFormAuthMembership" type="System.Web.Security.SqlMembershipProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" applicationName="FormAuthApplication" connectionStringName="FormAuthConnString" /> </providers> </membership> </system.web> See the snapshot of the web.config after adding the required elements. After adding this, you should be able to login using the credentials from SQL server. Try assigning a user as primary/secondary administrator for your site collection from Central Administration and login to your site using form authentication. If you made everything correct, you should be able to login. This means you have successfully completed configuration of STS Configuration of Web Application for Form Authentication As a last step, you need to modify the web.config of the form authentication web application. Once you have done this, you should be able to grant permissions to users stored in the membership database. Open the Web.config of the web application you created for form authentication. You can find the web.config for the application under the path C:\inetpub\wwwroot\wss\VirtualDirectories\<port number> Basically you need to add connection string, membership provider, role manager and update the people picker wild card configuration. Add the connection string (same as the one you added to the web.config in Central Administration). See the screenshot after the connection string has added. Search for <membership> in the web.config, you will find this inside system.web element. There will be other providers already available there. You add your form authentication membership provider (similar to the one added to Central Administration web.config) to the provider element under membership. Find the snapshot of membership configuration as follows. Search for <roleManager> element in web.config, add the new provider name under providers section of the roleManager element. See the snapshot of web.config after new provider added. Now you need to configure the peoplepickerwildcard configuration in web.config. As I specified earlier, this is to make sure, you can locate the users by entering a part of their username. Add the following line under the <PeoplePickerWildcards> element in web.config. See the screenshot of the peoplePickerWildcards element after the element has been added. Now you have completed all the setup for form authentication. Navigate to the web application. From the site actions -> site settings -> go to peope and groups Click on new -> add users, it will popup the people picker dialog. Click on the icon, select Form Auth, enter a username in the search textbox, and click on search icon. See the screenshot of admin search when I tried searching the users If it displays the user, it means you are done with the configuration. If you add users to the form authentication database, the users will be able to access SharePoint portal as normal.

  Read the article

• How to debug a web service written in PHP?

  - by nightcoder

  Hello, I've got a nice question here :) I need to debug my web service written in PHP. Its client is written in C#. After a couple of days of searching I realized this is not an easy task. At least it seems nobody knows the right solution. What is the problem in, actually? We have 2 popular PHP debugging libraries : PHP Debugger from NuSphere and XDebug extension. The problem is they both are controlled from URL query string or with the help of cookies. For example, to enable debugging with PHP Debugger you need to add ?DBGSESSID=xxx parameter to your URL or to have DBGSESSID cookie. But when your web service is called from the external client, the client doesn't have a cookie and doesn't add DBGSESSID url parameter. So how can we debug in this situation? PS. I don't want to write to log files, see request and response headers/data or something like this. I want normal step-by-step debugging and breakpoints. Anyone?

  Read the article

• What makes good web form styling for business applications?

  - by ProfK

  Styling forms (form elements) is something that even Eric Meyer prefers to avoid. However, most business forms, and that is where styling is at issue; 'contact us' forms are easy to style, put window estate at a premium, with more 'document level' (e.g. invoice) fields, plus 'detail level' (e.g. invoice line) fields. Factors I often find at play are: At my minimum, at least two horizontally adjacent fieldsets are required. In applications vs. public web pages, fixed positioning vs fluid layout is often better. Quantity of content is important, vs. exaggerated readability. Users know the system, and cues etc. take a back seat. In light of factors like these, is there any available guidence for styling web form based applications? Are there any CSS or JavaScript frameworks that would make my quest to style these applications better than Visual Studios still pathetic 'Auto-format' (what drugs were those people on? I will never take them.)

  Read the article

• Any web services with APIs for outsourcing webapp transactional email? [closed]

  - by Tauren

  My webapp needs to send customized messages to members and I'm wondering if there is an inexpensive and easy to use web service that would meet my needs. The types of mail I will be sending include: New account activation email (sent ASAP) Daily status report of user's account (sent anytime) Event reminders (sent at specific time) Specifically, I would like the following features: RESTful API to add an email message into the send queue A way to add a priority to each message (account signup activations should be sent immediately, while a daily status report could be sent anytime each day) They manage the sending of mail and the processing of bounces Possibly, they manage opt-out/opt-in features They offer features such as DKIM, VERP, etc. If their service determines an address is undeliverable (via VERP or other means, a user unsubscribes, etc), they make a RESTful call to my web service to notify me Nice if they had some reporting features, WebBugs, link tracking, etc. What I am NOT looking for is an email marketing service that caters only to sending out copies of the same mail to masses of recipients. I need to send out unique and custom messages to individuals. I had a chat with MailChimp about using their services for sending these types of messages and they said their service does not support customized emails per recipient. Edit: I just discovered a service called JangoSMTP that appears to meet many of my requirements. It provides an API for sending mail, supports DKIM, bounce management, and even feedback loops. Unfortunately, their idea of inexpensive doesn't mesh with mine, as it would cost $180/mo to send a single daily message to my 1000 users.

  Read the article

• Books about Javascript API design best practices

  - by Guilherme Defreitas

  Hi, Anyone can suggest good books about Javascript API design good practices? What are the common practices developed by Google, Twitter, Facebook in their APIs. Code organization, request control etc.

  Read the article

< Previous Page | 69 70 71 72 73 74 75 76 77 78 79 80  | Next Page >