Search Results

Search found 10845 results on 434 pages for 'member variables'.

Page 7/434 | < Previous Page | 3 4 5 6 7 8 9 10 11 12 13 14  | Next Page >

• persist values/variables from page to page

  - by Todd

  Hello, I'm wondering if there's another solution to my problem, that's considered more the Sharepoint way. FIrstly, my site is an Internet site, not Intranet. The problem is, all I'm trying to do is save values/variables from page to page in Sharepoint. I know the issue with Session Variables, but this seems to be the only way I can see to accomplish this. I know there are webparts that can store this value, but am I wrong in thinking this won't be persisted from page to page? Basically, I'll be extending the Content Query Web Part to dynamically filter it's results based off of a variable/value. The user chooses their 'area' from a dropdown, and the CQWP in the site will change and query results based off of this value (It will be a provincial structure as it is a Canadian site, so if someone chooses the province 'Ontario', this value is saved in a global variable, and these extended CQWP that are throughout the site, will get this value, and query lists flagged as Ontario). Is Session variables the only solution? Thanks everyone!

  Read the article

• Algorithm to Sort member into groups

  - by kasmanit

  I'll have to develop an application which the final purpose is to sort all the member into groups. Each group will have the same size. And I had to put the members into the groups several times during the execution of the program. To put the member into the groups, a lot of critria are to be look at, because we do not want that two people are put again together two time in the same execution of the program, of course if it's the only way to find a correct solution, it' fine, and there is a lot of other criteria, like some people can be willing to be always with another member. So to resume, we have n members to put in groups of size 8. After the first "round" we have to do again the algorithm to sort them differently. And a lot of critria may go in the calculation of the priority of each member Do you have any idea?

  Read the article

• what other bash variables are available during execution such as $USER that can assist on my script?

  - by semi-newbie

  This is related to question 19245, in that one of the responders answered the question in an awesome way, and very VERY clear to any newbie. Now here is a question that i can't seem to figure. i wrote a script for starting the vmware firefox plugin (don't worry. i gave that up and now run vBox VERY happily. i left vmware for my servers :) ) I needed to start the plugin as sudo, but i also needed to pass an argument (password) to it, that happen to be the same. So, if my password was Hello123, the command would be: sudo ./myscript.sh hi other Hello123 running from command line, the script would ask for my sudo password and then run. i wanted to capture THAT password and pass it as well. i also wanted to run graphically, so i tried gksudo, and there is an option -p that returns the password for variable assignment. well, that was a nightmare, because i would still get prompted for the original sudo: see below Find UserName vUser=$USER Find password (and hopefully enable sudo) vP=gksudo -p -D somedescriptiontext echo Execute command gksudo ./myscript.sh hi $vUser $vP and i still get prompted twice. so my question is tri-fold: is there a variable i can use for the password, just like there is one for user, $USER? is there a different way i should be assigning the value resulting of the command i have in $vP? i am wondering if executing the way i have it, does it in an uninitiated session and not the current one, since i am getting some addtl warning type errors on some variables blah blah i tried using Zenity to just capture the text, but then of course, i couldn't pass that value to sudo, so i could only use as a parameter, which puts me back in 2 prompts. Thanksssssssssss!

  Read the article

• In Ruby are there any related applications of the syntax: class << self ... end

  - by pez_dispenser

  class << self attr_accessor :n, :totalX, :totalY end The syntax above is used for defining class instance variables. But when I think about what syntax implies, it doesn't make any sense to me, so I'm wondering if this type of syntax is used for any other types of definitions. My point of confusion here is this: class << self The append operator normally means "add what's on the right to the object on the left". But in the context of this block, how does that add up to "put the contents of this block into the definition of the class instance rather than the instance"? For the same reason I'm confused as to why in one context class << self can define class instance variables while in another it seems to create class variables such as here: class Point # Instance methods go here class << self # Class methods go here end end

  Read the article

• C++ wrapper for C library

  - by Maximilien

  Hi, Recently I found a C library that I want to use in my C++ project. This code is configured with global variables and writes it's output to memory pointed by static pointers. When I execute my project I would like 2 instances of the C program to run: one with configuration A and one with configuration B. I can't afford to run my program twice, so I think there are 2 options: Make a C++ wrapper: The problem here is that the wrapper-class should contain all global/static variables the C library has. Since the functions in the C library use those variables I will have to create very big argument-lists for those functions. Copy-paste the C library: Here I'll have to adapt the name of every function and every variable inside the C library. Which one is the fastest solution? Are there other possibilities to run 2 instances of the same C source? Thanks, Max

  Read the article

• Seeking enlightenment - global variables in AppEngine (aeoid.get_current_user())

  - by jerd

  Hello This may be a 'Python Web Programming 101' question, but I'm confused about some code in the aeoid project (http://github.com/Arachnid/aeoid). here's the code: _current_user = None def get_current_user(): """Returns the currently logged in user, or None if no user is logged in.""" global _current_user if not _current_user and 'aeoid.user' in os.environ: _current_user = User(None, _from_model_key=os.environ['aeoid.user']) return _current_user But my understanding was that global variables were, ehm, global! And so different requests from different users could (potentially) access and update the same value, hence the need for sessions, in order to store per-user, non-global variables. So, in the code above, what prevents one request from believing the current user is the user set by another request? Sorry if this is basic, it's just not how i thought things worked. Thanks

  Read the article

• Variables versus constants versus associative arrays in PHP

  - by susmits

  I'm working on a small project, and need to implement internationalization support somehow. I am thinking along the lines of using constants to define a lot of symbols for text in one file, which could be included subsequently. However, I'm not sure if using variables is faster, or if I can get away with using associative arrays without too much of a performance hit. What's better for defining constant values in PHP, performance-wise -- constants defined using define("FOO", "..."), or simple variables like $foo = "...", or associative arrays like $symbols["FOO"]?

  Read the article

• Static Member Variables of the Same Class in C++

  - by helixed

  I'm trying to create a class which contains a static pointer to an instance of itself. Here's an example: A.h: #include <iostream> #ifndef _A_H #define _A_H class A { static A * a; }; A * a = NULL; #endif However, when I include A.h in another file, such as: #include "A.h" class B { }; I get the following error: ld: duplicate symbol _a in /Users/helixed/Desktop/Example/build/Example.build/Debug/Example.build/Objects-normal/x86_64/B.o and /Users/helixed/Desktop/Example/build/Example.build/Debug/Examplebuild/Objects-normal/x86_64/A.o I'm using the Xcode default compiler on Mac OS X Snow Leopard. Thanks, helixed

  Read the article

• Passing Flash variables to PHP.

  - by user340553

  Hi, I have a simple standalone application written in Visual Basic that I'm porting to a browser based application using PHP/javascript. The original VB application has some simple embedded flash games with token and point counters. The token and point values are being passed as variables between the application and the game. I'm trying to achieve the same effect in my PHP port without modifying the actionscript code( using the variables in actionscript that already exist). Below is Visual Basic code that's loading a value from a database and posting that value to flash using FlashVars: Private Sub loadPlayer() Try If CtblPoints.CheckPointsByID(mCard) Then objPoints = CtblPoints.GettblPointsByID(mCard) objPlayerAc = CtblPlayerAccount.GettblPlayerAccountByPlayerID(objPoints.AccountId) objPlayer = CtblPlayer.GettblPlayerByID(objPlayerAc.PlayerID) objPlayerBal = CtblPlayerBalance.GettblPlayerBalanceByID(objPlayerAc.PlayerID) objPlayerAcDetail = CtblPlayerAccountDetail.GettblPlayerAccountDetailByAmount(objPoints.AccountId) strTotalPoints = Convert.ToString(objPlayerAc.Points) strTotalWin = Convert.ToString(objPlayerBal.TokenAmount) 'Dim intTokenAmount As Decimal = Convert.ToDecimal(objPlayerBal.TokenAmount) 'strTotalWin = Convert.ToString(Convert.ToInt64(intTokenAmount * 100)) flashPlayer.Size = panelGame.Size flashPlayer.FlashVars = "totalEntries=" & strTotalPoints & "&credit=" & strTotalWin flashPlayer.LoadMovie(0, strGameFile) flashPlayer.Play() Else Me.Close() Dim frmInvCrd As New frmInvalidCard frmInvCrd.ShowDialog() End If Catch ex As Exception End Try I'm trying to recreate this in PHP, but I'm at a loss as to how to begin implementing it. The variables in flash are declared publicly, and global imports used: import com.atticmedia.console.*; import flash.display.*; import flash.events.*; import flash.geom.*; import flash.media.*; import flash.net.*; import flash.system.*; import flash.utils.*; First declaration of variable 'totalEntries' is: public var totalEntries:int = 0; and this is a snip of totalEntries being used in the actionscript public function notifyServerOfUnwonCredits(param1) { var remainder:* = param1; if (this.useServer) { this.targetWinAmount = 0; this.cancelUpdateOverTime = F9.setEnterFrame(this.updateOverTime); fscommand("OverTime", "" + remainder); this.flashVarsUpdatedAction = function () { originalTotalWin = totalWin; return; }// end function ; } else { this.setTotalEntries(100000); this.setTotalWin(0); } return; }// end function Eventually I'll be passing these values back to a mySQL database. Any insight into this would be extremely helpful, Thanks!

  Read the article

• Static Class Variables in Dynamic Library and Main Program

  - by Paul

  I am working on a project that has a class 'A' that contains a static stl container class. This class is included in both my main program and a .so file. The class uses the default(implicit, not declared) constructor/destructor. The main program loads the .so file using dlopen() and in its destructor, calls dlclose(). The program crashes after main exits when glibc calls the destructor for the static class member variable. The problem appears to be that when dlclose() is called, the destructor for the static variable is called, then when main exits() glibc also calls the destructor, resulting in a double free. I have 2 questions, namely: 1) In this particular case, why are there not two copies of the static variable(yes i know that sounds somewhat ridiculous, but since both the main program and .so file have a separately compiled 'A', shouldn't they each have one?) 2) Is there any way to resolve this issue without re-writing class 'A' to not contain static member variables?

  Read the article

• Defining Makefiles variables from a script

  - by Freddy

  I am creating a Makefile which I want it to be a single file for different architectures, OSes, libraries, etc. To do this I have a build specific XML file which defines the different configuration options for each architecture. The config file is read by Perl (it could be any language) and the Perl output returns something like: var1 := var1_value var2 := var2_value var3 := var3_value What I am trying to do is define this variables in my Makefile. From the makefile I am calling my readconfig script and it is giving the correct output, but I have not been able to get this variables as part of my Makefile. I have tried the use of eval and value, but none of them have work (although it could be an issue of me not knowing how to use them. In overall what I am trying to do is something like: read_config: $(eval (perl '-require "readConfig.pl"')) @echo $(var1) It could be assumed I am using only GNU Make behavior. Things I could not change: Config file is on XML Using Perl as a XML parser

  Read the article

• Problem sending php variables to flash game, on facebook

  - by FlashWars

  When I run the app for the first time in a session it works great i get all data form Database(if i logout, and enter with a diffrent account)the swf does not receive the variables. If i run manually the script typing the url address in the browser (typing: http://myserver.com/app/variables.php), and refresh the facebook app, it receives the data perfectly.How can i fix this?I used the URLVariables, URLRequest and flashvars but still with no succes.I asked for help on many forums but without succes, apparently there are many in my situation.Could this porblem be due the fact tha facebook does not allow flash to talk outside? Any help would be highly apreciated!Thanks!!

  Read the article

• Why are my ActiveRecord class instance variables disappearing after the first request in development

  - by Paul C

  I have a class instance variable on one of my AR classes. I set its value at boot with an initializer and, after that, never touch it again except to read from it. In development mode, this value disappears after the first request to the web server. However, when running tests, using the console or running the production server this does not happen. # The AR class class Group < ActiveRecord::Base class << self attr_accessor :path end end # The initializer Group.path = File.join(RAILS_ROOT, "public", "etc") # First request in a view %p= Group.path #=> "/home/rails/app/public/etc" # Second request in a view %p= Group.path #=> nil Is there something about development mode that nukes instance variables from classes with each request? If so, is there a way to disable this for specific variables or classes?

  Read the article

• Another Call to a member function get_segment() on a non-object question

  - by hogofwar

  I get the above error when calling this code: <? class Test1 extends Core { function home(){ ?> This is the INDEX of test1 <? } function test2(){ echo $this->uri->get_segment(1); //this is where the error comes from ?> This is the test2 of test1 testing URI <? } } ?> I get the error where commentated. This class extends this class: <?php class Core { public function start() { require("funk/funks/libraries/uri.php"); $this->uri = new uri(); require("funk/core/loader.php"); $this->load = new loader(); if($this->uri->get_segment(1) != "" and file_exists("funk/pages/".$this->uri->get_segment(1).".php")){ include("funk/pages/". $this->uri->get_segment(1).".php"); $var = $this->uri->get_segment(2); if ($var != ""){ $home= $this->uri->get_segment(1); $Index= new $home(); $Index->$var(); }else{ $home= $this->uri->get_segment(1); $Index = new $home(); $Index->home(); } }elseif($this->uri->get_segment(1) and ! file_exists("funk/pages/".$this->uri->get_segment(1).".php")){ echo "404 Error"; }else{ include("funk/pages/index.php"); $Index = new Index(); $Index->home(); //$this->Index->index(); echo "<!--This page was created with FunkyPHP!-->"; } } } ?> And here is the contents of uri.php: <?php class uri { private $server_path_info = ''; private $segment = array(); private $segments = 0; public function __construct() { $segment_temp = array(); $this->server_path_info = preg_replace("/\?/", "", $_SERVER["PATH_INFO"]); $segment_temp = explode("/", $this->server_path_info); foreach ($segment_temp as $key => $seg) { if (!preg_match("/([a-zA-Z0-9\.\_\-]+)/", $seg) || empty($seg)) unset($segment_temp[$key]); } foreach ($segment_temp as $k => $value) { $this->segment[] = $value; } unset($segment_temp); $this->segments = count($this->segment); } public function segment_exists($id = 0) { $id = (int)$id; if (isset($this->segment[$id])) return true; else return false; } public function get_segment($id = 0) { $id--; $id = (int)$id; if ($this->segment_exists($id) === true) return $this->segment[$id]; else return false; } } ?> i have asked a similar question to this before but the answer does not apply here. I have rewritten my code 3 times to KILL and Delimb this godforsaken error! but nooooooo....

  Read the article

• Accessing the shadowed field from enclosed member class (Java)

  - by kolm

  Hi there, is it possible to access a shadowed field of an enclosing class from the enclosed one in Java? public class Inherit { public int a = 3; private int b = 5; public class Inheriting { public int a = 23; private int d = 8; public void f() { System.out.println("Here I want to get a = 3"); ... } } } Cheers!

  Read the article

• C++ static variables dynamic

  - by Zibd

  Is it possible or makes sense to have static dynamic variables on a class, initialized with new operator?

  Read the article

• Sending variables in URLs in PHP with echo

  - by alexpelan

  Hi all, I can't really find good guidelines through google searches of the proper way to escape variables in URLs. Basically I am printing out a bunch of results from a mysql query in a table and I want one of the entries in each row to be a link to that result's page. I think this is easy, that I'm just missing a apostrophe or backslash somewhere, but I can't figure it out. Here's the line that's causing the error: echo "<a href = \"movies.php/?movie_id='$row['movie_id']'\"> Who Owns It? </a> "; and this is the error I'm getting: Parse error: syntax error, unexpected T_ENCAPSED_AND_WHITESPACE, expecting T_STRING or T_VARIABLE or T_NUM_STRING If you could elaborate in your answers about general guidelines for working with echo and variables in urls, that would be great. Thanks.

  Read the article

• vc++ - static member is showing error

  - by prabhakaran

  I am using vc++(2010). I am trying to create a class for server side socket. Here is the header file #include<winsock.h> #include<string> #include<iostream> using namespace std; class AcceptSocket { // static SOCKET s; protected: SOCKET acceptSocket; public: AcceptSocket(){}; void setSocket(SOCKET socket); static void EstablishConnection(int portNo,string&); static void closeConnection(); static void StartAccepting(); virtual void threadDeal(); static DWORD WINAPI MyThreadFunction(LPVOID lpParam); }; SOCKET AcceptSocket::s; and the corresponding source file #include<NetWorking.h> #include<string> void AcceptSocket::setSocket(SOCKET s) { acceptSocket=s; } void AcceptSocket::EstablishConnection(int portno,string &failure) { WSAData w; int error = WSAStartup(0x0202,&w); if(error) failure=failure+"\nWSAStartupFailure"; if(w.wVersion != 0x0202) { WSACleanup(); failure=failure+"\nVersion is different"; } SOCKADDR_IN addr; addr.sin_family=AF_INET; addr.sin_port=htons(portno); addr.sin_addr.s_addr=htonl(INADDR_ANY); AcceptSocket::s=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP); if(AcceptSocket::s == INVALID_SOCKET) failure=failure+"\nsocket creating error"; if(bind(AcceptSocket::s,(LPSOCKADDR) &addr,sizeof(addr)) == SOCKET_ERROR) failure=failure+"\nbinding error"; listen(AcceptSocket::s,SOMAXCONN); } void AcceptSocket::closeConnection() { if(AcceptSocket::s) closesocket(AcceptSocket::s); WSACleanup(); } void AcceptSocket::StartAccepting() { sockaddr_in addrNew; int size=sizeof(addrNew); while(1) { SOCKET temp=accept(AcceptSocket::s,(sockaddr *)&addrNew,&size); AcceptSocket * tempAcceptSocket=new AcceptSocket(); tempAcceptSocket->setSocket(temp); DWORD threadId; HANDLE thread=CreateThread(NULL,0,MyThreadFunction,(LPVOID)tempAcceptSocket,0,&threadId); } } DWORD WINAPI AcceptSocket::MyThreadFunction(LPVOID lpParam) { AcceptSocket * acceptsocket=(AcceptSocket *) lpParam; acceptsocket->threadDeal(); return 1; } void AcceptSocket::threadDeal() { "You didn't define threadDeal in the derived class"; } Now the main.cpp is #include<Networking.h> int main() { } When I am compiling The error I got is Error 1 error LNK2005: "private: static unsigned int AcceptSocket::s" (?s@AcceptSocket@@0IA) already defined in NetWorking.obj C:\Documents and Settings\prabhakaran\Desktop\check\check\main.obj check Error 2 error LNK1169: one or more multiply defined symbols found C:\Documents and Settings\prabhakaran\Desktop\check\Debug\check.exe 1 1 check Now anybody please enlighten me about this issue

  Read the article

• Printing out variables in c changes values of variables

  - by George Wilson

  I have an odd problem with some c-programme here. I was getting some wrong values in a matrix I was finding the determinant of and so I started printing variables - yet found that by printing values out the actual values in the code changed. I eventually narrowed it down to one specific printf statement - highlighted in the code below. If I comment out this line then I start getting incorrect values in my determinent calculations, yet by printing it out I get the value out I expect Code below: #include <math.h> #include <stdio.h> #include <stdlib.h> #define NUMBER 15 double determinant_calculation(int size, double array[NUMBER][NUMBER]); int main() { double array[NUMBER][NUMBER], determinant_value; int size; array[0][0]=1; array[0][1]=2; array[0][2]=3; array[1][0]=4; array[1][1]=5; array[1][2]=6; array[2][0]=7; array[2][1]=8; array[2][2]=10; size=3; determinant_value=determinant_calculation(size, array); printf("\n\n\n\n\n\nDeterminant value is %lf \n\n\n\n\n\n", determinant_value); return 0; } double determinant_calculation(int size, double array[NUMBER][NUMBER]) { double determinant_matrix[NUMBER][NUMBER], determinant_value; int x, y, count=0, sign=1, i, j; /*initialises the array*/ for (i=0; i<(NUMBER); i++) { for(j=0; j<(NUMBER); j++) { determinant_matrix[i][j]=0; } } /*does the re-cursion method*/ for (count=0; count<size; count++) { x=0; y=0; for (i=0; i<size; i++) { for(j=0; j<size; j++) { if (i!=0&&j!=count) { determinant_matrix[x][y]=array[i][j]; if (y<(size-2)) { y++; } else { y=0; x++; } } } } //commenting this for loop out changes the values of the code determinent prints -7 when commented out and -3 (expected) when included! for (i=0; i<size; i++) { for(j=0; j<size; j++){ printf("%lf ", determinant_matrix[i][j]); } printf("\n"); } if(size>2) { determinant_value+=sign*(array[0][count]*determinant_calculation(size-1 ,determinant_matrix)); } else { determinant_value+=sign*(array[0][count]*determinant_matrix[0][0]); } sign=-1*sign; } return (determinant_value); } I know its not the prettiest (or best way) of doing what I'm doing with this code but it's what I've been given - so can't make huge changes. I don't suppose anyone could explain why printing out the variables can actually change the values? or how to fix it because ideally i don't want to!!

  Read the article

• Accessing XAML Object Variables in XAML

  - by Asryael

  So, what I'm trying to do is access my Form's width and/or height to use in a storyboard. Essentially, I have a Translate Transform animation to slide what are essentially two pages. The animation works fine with hard coded From/To variables, however I need to use soft variables that enable the animation to start from the left/right of my form no matter what size it is. <Storyboard x:Key="SlideLeftToRight" TargetProperty="RenderTransform.(TranslateTransform.X)" AccelerationRatio=".4" DecelerationRatio=".4"> <DoubleAnimation Storyboard.TargetName="PageViewer" Duration="0:0:0.6" From="WindowWidth" To="0"/> <DoubleAnimation Storyboard.TargetName="BorderVisual" Duration="0:0:0.6" From="0" To="NegativeWindowWidth"/> </Storyboard> However, I have no idea how to do so. Any help is greatly appreciated. EDIT: I'm guessing it has something to do with: From="{Binding Width, Source=MainWindow}" However, when I attempt this, I don't know how to make it negative.

  Read the article

• In game programming are global variables bad?

  - by Joe.F

  I know my gut reaction to global variables is "badd!" but in the two game development courses I've taken at my college globals were used extensively, and now in the DirectX 9 game programming tutorial I am using (www.directxtutorial.com) I'm being told globals are okay in game programming ...? The site also recommends using only structs if you can when doing game programming to help keep things simple. I'm really confused on this issue, and all the research I've been trying to do is very confusing. I realize there are issues when using global variables (threading issues, they make code harder to maintain, the state of them is hard to track etc) but also there is a cost associated with not using globals, I'd have to pass a loooot of information around very often which can be confusing and I imagine time-costing, although I guess pointers would speed the process up (this is my first time writing a game in C++.) Anyway, I realize there is probably no "right" or "wrong" answer here since both ways work, but I want my code to be as proper as I can so any input would be good, thank you very much!

  Read the article

• Generate a List of All Variables used in a Visual Studio Project

  - by Jammie

  Is it possible to generate a list of all the variables used in a visual studio project?

  Read the article

• class member access specifiers

  - by pdehaan

  I understand what the typical access specifiers are, and what they mean. 'public' members are accessible anywhere, 'private' members are accessible only by the same class and friends, etc. What I'm wondering is what, if anything, this equates to in lower-level terms. Are their any post-compilation functional differences between these beyond the high-level restrictions (what can access what) imposed by the language (c++ in this case) they're used in. Another way to put it - if this were a perfect world where programmers always made good choices (like not accessing members that may change later and using only well defined members that should stay the same between implementations), would their be any reason to use these things?

  Read the article

• Trying to instantiate a class member in C++ with a variable name

  - by MarcZero

  Hello. I am writing a program for class that is asking us to create a class of "book". We are then supposed to create new instantiations of that class upon demand from the user. I am new to C++ so I am attempting to code this out but am running into a problem. The main problem is how do I instantiate a class with a variable if I don't know how many I will have to do ahead of time. The user could ask to add 1 book or 1000. I am looking at this basic code: This is the simple code I started with. I wanted to have an index int keep a number and have the book class I create be called by that int (0, 1, 2, etc...) So I attempted to convert the incoming index int into a string, but I'm kind of stuck from here. void addBook(int index){ string bookName; std::stringstream ss; ss << index; book bookName; cout << "Enter the Books Title: "; cin >> bookName.title; } But obviously this doesn't work as "bookName" is a string to the computer and not the class member I tried to create. All of the tutorials I have seen online and in my text show the classes being instantiated with names in the code, but I just don't know how to make it variable so I can create any amount of "books" that the user might want. Any insight on this would be appreciated. Thank you for your time.

  Read the article

• design a model for a system of dependent variables

  - by dbaseman

  I'm dealing with a modeling system (financial) that has dozens of variables. Some of the variables are independent, and function as inputs to the system; most of them are calculated from other variables (independent and calculated) in the system. What I'm looking for is a clean, elegant way to: define the function of each dependent variable in the system trigger a re-calculation, whenever a variable changes, of the variables that depend on it A naive way to do this would be to write a single class that implements INotifyPropertyChanged, and uses a massive case statement that lists out all the variable names x1, x2, ... xn on which others depend, and, whenever a variable xi changes, triggers a recalculation of each of that variable's dependencies. I feel that this naive approach is flawed, and that there must be a cleaner way. I started down the path of defining a CalculationManager<TModel> class, which would be used (in a simple example) something like as follows: public class Model : INotifyPropertyChanged { private CalculationManager<Model> _calculationManager = new CalculationManager<Model>(); // each setter triggers a "PropertyChanged" event public double? Height { get; set; } public double? Weight { get; set; } public double? BMI { get; set; } public Model() { _calculationManager.DefineDependency<double?>( forProperty: model => model.BMI, usingCalculation: (height, weight) => weight / Math.Pow(height, 2), withInputs: model => model.Height, model.Weight); } // INotifyPropertyChanged implementation here } I won't reproduce CalculationManager<TModel> here, but the basic idea is that it sets up a dependency map, listens for PropertyChanged events, and updates dependent properties as needed. I still feel that I'm missing something major here, and that this isn't the right approach: the (mis)use of INotifyPropertyChanged seems to me like a code smell the withInputs parameter is defined as params Expression<Func<TModel, T>>[] args, which means that the argument list of usingCalculation is not checked at compile time the argument list (weight, height) is redundantly defined in both usingCalculation and withInputs I am sure that this kind of system of dependent variables must be common in computational mathematics, physics, finance, and other fields. Does someone know of an established set of ideas that deal with what I'm grasping at here? Would this be a suitable application for a functional language like F#? Edit More context: The model currently exists in an Excel spreadsheet, and is being migrated to a C# application. It is run on-demand, and the variables can be modified by the user from the application's UI. Its purpose is to retrieve variables that the business is interested in, given current inputs from the markets, and model parameters set by the business.

  Read the article

< Previous Page | 3 4 5 6 7 8 9 10 11 12 13 14  | Next Page >