Search Results

Search found 26869 results on 1075 pages for 'library design'.

Page 255/1075 | < Previous Page | 251 252 253 254 255 256 257 258 259 260 261 262  | Next Page >

• Inheritance vs specific types in Financial Modelling for cashflows

  - by BlueTrin

  Hello, I have to program some financial applications where I have to represent a schedule of flows. The flows can be of 3 types: - fee flow (just a lump payment at some date) - floating rate flow (the flow is dependant of an interest rate to be determined at a later date) - fixed rate flow (the flow is dependant of an interest rate determined when the deal is done) I need to keep the whole information and I need to represent a schedule of these flows. Originally I wanted to use inheritance and create three classes FeeFlow, FloatingFlow, FixedFlow all inheriting from ICashFlow and implement some method GetFlowType() returning an enum then I could dynamic_cast the object to the correct type. That would allow me to have only one vector to represent my schedule. What do you think of this design, should I rather use three vectors vector, vector and vector to avoid the dynamic casts ?

  Read the article

• XCode : linking different libraries depending on architecture (cpu type)

  - by kudorgyozo

  I'm developing an iPhone app which needed voip support so i added the ARM version of pjsip libraries. But if I'm using the iPhone simulator i want to link the i386 version of the libraries. How can i do that?

  Read the article

• How can I merge two Linq IEnumerable<T> queries without running them?

  - by makerofthings7

  How do I merge a List<T> of TPL-based tasks for later execution? public async IEnumerable<Task<string>> CreateTasks(){ /* stuff*/ } My assumption is .Concat() but that doesn't seem to work: void MainTestApp() // Full sample available upon request. { List<string> nothingList = new List<string>(); nothingList.Add("whatever"); cts = new CancellationTokenSource(); delayedExecution = from str in nothingList select AccessTheWebAsync("", cts.Token); delayedExecution2 = from str in nothingList select AccessTheWebAsync("1", cts.Token); delayedExecution = delayedExecution.Concat(delayedExecution2); } /// SNIP async Task AccessTheWebAsync(string nothing, CancellationToken ct) { // return a Task } I want to make sure that this won't spawn any task or evaluate anything. In fact, I suppose I'm asking "what logically executes an IQueryable to something that returns data"? Background Since I'm doing recursion and I don't want to execute this until the correct time, what is the correct way to merge the results if called multiple times? If it matters I'm thinking of running this command to launch all the tasks var AllRunningDataTasks = results.ToList(); followed by this code: while (AllRunningDataTasks.Count > 0) { // Identify the first task that completes. Task<TableResult> firstFinishedTask = await Task.WhenAny(AllRunningDataTasks); // ***Remove the selected task from the list so that you don't // process it more than once. AllRunningDataTasks.Remove(firstFinishedTask); // TODO: Await the completed task. var taskOfTableResult = await firstFinishedTask; // Todo: (doen't work) TrustState thisState = (TrustState)firstFinishedTask.AsyncState; // TODO: Update the concurrent dictionary with data // thisState.QueryStartPoint + thisState.ThingToSearchFor Interlocked.Decrement(ref thisState.RunningDirectQueries); Interlocked.Increment(ref thisState.CompletedDirectQueries); if (thisState.RunningDirectQueries == 0) { thisState.TimeCompleted = DateTime.UtcNow; } }

  Read the article

• Why should I use PropertyProxyValidator? ASP.NET

  - by user102533

  I understand thatthe PropertyProxyValidator integrates with the ASP.NET UI. But, it cannot do client side validation. How would it be any different from throwing in a label in the UI and populating the errors on the server side? Also, If I am using Validation Application Block, what approaches do you suggest for client side validation if I don't want to duplicate rules on server and client side?

  Read the article

• Java Double entry table

  - by Tom

  Hi, Does anyone know a double entry table implementation in java I can download ? I need to do something like this 1 2 3 _______ a| x y z b| h l m c| o a k table.get(a,1) would return x Of course, it should use any Object as key, value, etc Thanks in advance

  Read the article

• Lazy loading? Better avoiding it?

  - by Charlie Pigarelli

  I just read about this design pattern: Lazy Load. And, since in the application i'm working on i have all the classes in one folder, i was wondering if this pattern could just make me avoiding the include() function for every class. I mean: It's nice to know that if i forgot to include a class, PHP, before falling into an error, trough an __autoload() function try to get it. But is it fine enough to just don't care about including classes and let PHP do it by your own every time? Or we should write __autoload() just in case it is needed?

  Read the article

• Makefile option/rule to handle missing/removed source files

  - by b3nj1

  http://stackoverflow.com/questions/239004/need-a-makefile-dependency-rule-that-can-handle-missing-files gives some pointers on how to handle removed source files for generating .o files. I'm using gcc/g++, so adding the -MP option when generating dependencies works great for me, until I get to the link stage with my .a file... What about updating archives/libraries when input sources go away? This works OK for me, but is there a cleaner way (ie, something as straightforward as the g++ -MP option)? #BUILD_DIR is my target directory (includes Debug/Release and target arch) #SRC_OUTS are my .o files LIBATLS_HAS = $(shell nm ${BUILD_DIR}/libatls.a | grep ${BUILD_DIR} | sed -e 's/.*(//' -e 's/).*://') LIBATLS_REMOVE = $(filter-out $(notdir ${SRC_OUTS}), ${LIBATLS_HAS}) ${BUILD_DIR}/libatls.a: ${BUILD_DIR}/libatls.a(${SRC_OUTS}) ifneq ($(strip ${LIBATLS_REMOVE}),) $(AR) -d $@ ${LIBATLS_REMOVE} endif

  Read the article

• What tag libraries you know for J2EE JSP, something like displaytag ?

  - by DFG

  What tag libraries you know for J2EE - JSP, something like displaytag ?

  Read the article

• Using Remote Web Server to Initialize iPhone App

  - by Chris_K

  My iPhone app relies on a vendor's XML feed to provide data. But that feed is not locked down. The vendor could change the format of the XML at any time, although so far they've promised not to. Since I might want to tell my app to use a different URL for its data source, I'd like to set up a single "Command Central" Web page, on my own server, to direct the app to the correct data source. In other words, each time my app starts, in the background and unseen by the user, it would visit "http://www.myserver.com/iphoneapp_data_sources.xml" to retrieve the URL for retrieving data from my vendor. That way, if my vendor suddenly changes the exact URL or the XML feed that the app needs, I can update that Web page and ensure that all installations of the app are using the correct XML feed. Does anyone have any advice or examples showing this kind of approach? It seems as if this must be a common problem, but so far I haven't found a well-established design pattern that fits it.

  Read the article

• MooTools Problem in IE with Request

  - by trobrock

  I have this class method in a mootools class: getData : function(){ var r = new Request.JSON({ url : this.container.getAttribute('data-url'), method : 'post', onSuccess : function(j){ this.cards = j; this.prepareQuiz(); }.bind(this) }).send(); }, In any browser aside from IE this works fine, but in IE I get a this.cards is not defined in a method that occurs after the this.prepareQuiz method does it's stuff. I narrowed the problem to this section by adding an if ($defined(this.cards)) before the this.prepareQuiz call and if I just keep refreshing the page 1 out of every 5 or so times it will work. So the this.cards variable is not being set some of the time for some reason. Why would this happen?

  Read the article

• Lexer written in Javascript?

  - by Phobis

  I have a project where a user needs to define a set of instructions for a ui that is completely written in javascript. I need to have the ability to parse a string of instructions and then translate them into instructions. Is there any libraries out there for parsing that are 100% javascript? Or a generator that will generate in javascript? Thanks!

  Read the article

• Validate DateTime in Validation Application Block

  - by Wilson

  Hello All! How to validate DateTime by Validation Application Block, to not be more than DateTime.Now? thanks.

  Read the article

• What library can I use to do simple, lightweight message passing?

  - by Mike

  I will be starting a project which requires communication between distributed nodes(the project is in C++). I need a lightweight message passing library to pass very simple messages(basically just strings of text) between nodes. The library must have the following characteristics: No external setup required. I need to be able to get everything up-and-running in my code - I don't want to require the user to install any packages or edit any configuration files(other than a list of IP addresses and ports to connect to). The underlying protocol which the library uses must be TCP(or if it is UDP, the library must guarantee the eventual receipt of the message). The library must be able to send and receive arbitrarily large strings(think up to 3GB+). The library needn't support any security mechanisms, fault tolerance, or encryption - I just need it to be fast, simple, and easy to use. I've considered MPI, but concluded it would require too much setup on the user's machine for my project. What library would you recommend for such a project? I would roll my own, but due to time constraints, I don't think that will be feasible.

  Read the article

• Does .dll and .lib differ by programming language?

  - by user198729

  Say,if the .dll or .lib is written in C,can it be used by other languages like PHP/Python?

  Read the article

• Is it okay if my ViewModel 'creates' bindable user controls for my View?

  - by j0rd4n

  I have an entry-point View with a tab control. Each tab is going to have a user control embedded within it. Each embedded view inherits from the same base class and will need to be updated as a key field on the entry-point view is updated. I'm thinking the easiest way to design this page is to have the entry-point ViewModel create and expose a collection of the tabbed views so the entry-point View can just bind to the user control elements using a DataTemplate on the tab control. Is it okay for a ViewModel to instantiate and provide UI elements for its View?

  Read the article

• Have to put files in static_dir but need to read them afterwards

  - by SanjamX

  I just started using google app engine. In order to use templates, I'm using jinja2. I want to add images dynamically after I set the width and height of the img tag. I used PIL in order to read the image size and put the one I want. However when I open the image with PIL, I need it not to be in a static_dir and to put the image in the img tag, I need it to be in the static_dir. As a testing solution I've copied the folder to see if I get results and I did. But as you can see having each image saved twice is kind of bad.

  Read the article

• Is foreign key reference from two different primary key from two different tables valid?

  - by arundex

  I have a foreign key that has to refer primary keys of two different tables. Table 1: animal animal_ id (primary key) Table 2: bird bird_ id (primary key) Table 3: Pet_info pet_id, type ENUM ('bird', 'animal') foreign key (pet_ id) references animal(animal_id), bird(bird_id) So, I need to check for pet_id either from animal or bird table depending on the need. Is this valid? Or should I go for some restructuring . . . NOTE: I referred this . . but I'm not sure whether I have to change my existing design

  Read the article

• C# DDD Populate Immutable Objects

  - by Russel

  Hi I have a immutable Customer class in my domain assembly. It contains the following GET properties : id, firstname and lastname. I have a CustomerRepository class in my persistence assembly. In turn, this CustomerRepository class should populate and return a Customer object using a remote web-serivce. My Customer class contains no setter properties and it contains a private constructor. The reason - I dont want the UI developer to get the wrong idea - He should not be able to create or change a Customer object. My question: How do I get my CustomerRepository to populate my Customer object. Reflection? Or should I sacrifice my design and enable a public constructor for constructing the customer object?

  Read the article

• Java: 3rd libraries Fast from some package management thing?

  - by HH

  Frustrated in finding the .jar -balls like google collections or "package org.apache.commons.io;". Is there some utility to get them fast like the style-"apt-get source app"? "get-java-jar-ball-3rd source apache commons"?

  Read the article

• Should I consider memmove() O(n) or O(1) ?

  - by Andrei Ciobanu

  Hello, this may be a silly question, but I want to calculate the complexity of one of my algorithms, and I am not sure what complexity to consider for the memmove() function. Can you please help / explain ? void * memmove ( void * destination, const void * source, size_t num ); So is the complexity O(num) or O(1). I suppose it's O(num), but I am not sure as I lack for now the understanding of what's going on under the hood.

  Read the article

• Stuck with the math in a Flash project, would parsing engine help?

  - by VideoDnd

  I've been stuck with the math in a Flash project? It's a loose design pattern my director formulated. My goal is to keep the project object oriented, and get 'non Flash obstacles' off my plate. Do you recommend using parsing engines for processing math? XML values going to AS3, updating a changing acceleration formula. I don't hate math, but it just doesn't seem OOP or good project planning to have the math stuck in Flash. Your comments are welcome.

  Read the article

• System("pause"); - Why is it wrong?

  - by Faken

  Here's a question that I don't quite understand: The command, System("pause"); is taught to new programmers as a way to pause a program and wait for a keyboard input to continue. However, it seems to be frowned on by many veteran programmers as something that should not be done in varying degrees. Some people say it is fine to use. Some say it is only to be used when you are locked in your room and no one is watching. Some say that they will personally come to your house and kill you if you use it. I, myself am a new programmer with no formal programming training. I use it because I was taught to use it. What I don't understand is that if it is not something to be used, then why was I taught to use it? Or, on the flip side, is it really not that bad after all? What are your thoughts on this subject?

  Read the article

• Session State Anti-Pattern

  - by Curiosity

  I know the SOLID principles and other design patterns fairly well and have been programming for some time now - seeing many a bit of code throughout the years. Having said that, I'm having trouble coming up with a name to give the pattern, or lack thereof, to bits of code I've been dealing with at a current engagement. The application is an ASP.NET C# WebForms application, backed by a SQL Server/Mainframe backend (more mainframe than backend) and it's riddled with Session State properties being accessed/mutated from multiple pages/classes. Accessing/mutating global variables/application state was usually shunned upon while I was in school. Apparently the creators of this magnificent application didn't think it was such a bad idea. Question: Is there a name for such a pattern/anti-pattern that relies so heavily on Session State? I'd like to call the pig by its name ...

  Read the article

• Stored Procedure or calculations via IQueryable?

  - by Shawn Mclean

  This is a question that is based on choosing performance over design practices. If I have a method that will be executed many times a second; public static IQueryable<IPerson> InRadius(this IQueryable<IPerson> query, Coordinate center, double radius) { return (from u in query where CallHeavyMathFormula(u, center, radius) select u); } This extension method for IQueryable generates a SQL that does some heavy maths calculation (Cosine, Sine, etc). This would mean the application sends 1-2KB of sql to the server per call. I've heard of placing all application logic, in your application. I also would like to change to a database such as azure or one of those scalable databases in the future. How do I handle something like this? Should I leave it as it is now or write stored procedures? How do applications like twitter or facebook do it?

  Read the article

• using asp.net membership provider in a dll

  - by Keith Barrows

  I've used Membership Providers in web apps over the last several years. I now have a new "request" for an internal project at work. They would like a service (not a web service) to do a quick authenticate against. Basically, exposing the ValidateUser(UserName, Password) method... I am building this in a DLL that will sit with our internal web site. What is the best approach to make this work? The DLL will not reference the web app and the web app will reference the DLL. How do I make the DLL aware of the Membership Provider? TIA PS: If this has been answered elsewhere please direct me to that... EDIT: I found an article on using ASP.NET Membership with WinForms and/or WPF applications. Unfortunately, these depend on an app.config file. A DLL appears to not use the app.config once published. If I am wrong, please set me straight! The article is here: http://aspalliance.com/1595_Client_Application_Services__Part_1.all

  Read the article

< Previous Page | 251 252 253 254 255 256 257 258 259 260 261 262  | Next Page >