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  • [c++] - Help about class and error: C3861

    - by Chelsea_cole
    Can someone help me in this error? in "cDef.h" : #pragma once class cDef { public: static int STATE_LOGO; static int STATE_MENU; static int MESSAGE_ENTER; static int MESSAGE_UPDATE; static int MESSAGE_PAINT; static int MESSAGE_EXIT; }; in "GameState.h": #pragma once #ifndef _GameState_ #define _GameState_ #include "cDef.h" class MainGame; class GameState; class GameState { public: MainGame *mg; int GAME_STATE_DEF; virtual void MessengeEnter(int message) = 0; virtual void MessengeUpdate(int message,int keys) = 0; virtual void MessengePaint(int message,CDC *pDc) = 0; void StateHandler(int message,CDC *pDc,int keys); public: GameState(void); public: ~GameState(void); }; #endif in "GameState.cpp": #include "StdAfx.h" #include "GameState.h" GameState::GameState(void) { GAME_STATE_DEF = -1; } GameState::~GameState(void) { } void GameState::StateHandler(int message,CDC *pDc,int keys) { if(message == cDef.MESSAGE_ENTER) { MessageEnter(message); } if(message == cDef.MESSAGE_UPDATE) { MessageUpdate(message,keys); } if(message == cDef.MESSAGE_PAINT) { MessagePaint(message,pDC); } } error: warning C4832: token '.' is illegal after UDT 'cDef' see declaration of 'cDef' error C3861: 'MessageUpdate': identifier not found error C3861: 'MessageEnter': identifier not found error C3861: 'MessagePaint': identifier not found ..... Thanks in advance!

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  • sum of square of each elements in the vector using for_each

    - by pierr
    Hi, As the function accepted by for_each take only one parameter (the element of the vector), I have to define a static int sum = 0 somewhere so that It can be accessed after calling the for_each . I think this is awkward. Any better way to do this (still use for_each) ? #include <algorithm> #include <vector> #include <iostream> using namespace std; static int sum = 0; void add_f(int i ) { sum += i * i; } void test_using_for_each() { int arr[] = {1,2,3,4}; vector<int> a (arr ,arr + sizeof(arr)/sizeof(arr[0])); for_each( a.begin(),a.end(), add_f); cout << "sum of the square of the element is " << sum << endl; } In Ruby, We can do it this way: sum = 0 [1,2,3,4].each { |i| sum += i*i} #local variable can be used in the callback function puts sum #=> 30 Would you please show more examples how for_each is typically used in practical programming (not just print out each element)? Is it possible use for_each simulate 'programming pattern' like map and inject in Ruby (or map /fold in Haskell). #map in ruby >> [1,2,3,4].map {|i| i*i} => [1, 4, 9, 16] #inject in ruby [1, 4, 9, 16].inject(0) {|aac ,i| aac +=i} #=> 30 EDIT: Thank you all. I have learned so much from your replies. We have so many ways to do the same single thing in C++ , which makes it a little bit difficult to learn. But it's interesting :)

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  • Segmentation Fault when trying to push a string to the back of a list.

    - by user308012
    I am trying to write a logger class for my C++ calculator, but I'm experiencing a problem while trying to push a string into a list. I have tried researching this issue and have found some information on this, but nothing that seems to help with my problem. I am using a rather basic C++ compiler, with little debugging utilities and I've not used C++ in quite some time (even then it was only a small amount). My code: #ifndef _LOGGER_H_ #define _LOGGER_H_ #include <iostream> #include <list> #include <string> using std::cout; using std::cin; using std::endl; using std::list; using std::string; class Logger { private: list<string> *mEntries; public: Logger() { // Initialize the entries list mEntries = new list<string>(); } ~Logger() { // Release the list mEntries->clear(); delete mEntries; } // Public Methods void WriteEntry(string entry) { // *** BELOW LINE IS MARKED WITH THE ERROR *** mEntries->push_back(string(entryData)); } void DisplayEntries() { cout << endl << "**********************" << endl << "* Logger Entries *" << endl << "**********************" << endl << endl; for(list<string>::iterator it = mEntries->begin(); it != mEntries->end(); it++) { cout << *it << endl; } } }; #endif I am calling the WriteEntry method by simply passing in a string, like so: mLogger->WriteEntry("Testing"); Any advice on this would be greatly appreciated.

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  • how to switch views according to command

    - by Veer
    I've a main view and many usercontrols. The main view contains a two column grid, with the first column filled with a listbox whose datatemplate consists of a usercontrol and the second column filled with another usercontrol. These two usercontrols have the same datacontext. MainView: <Grid> //Column defs ... <ListView Grid.Column="0" ItemSource="{Binding Foo}"> ... <DataTemplate> <Views: FooView1 /> </DataTemplate> </ListView> <TextBlock Text="{Binding Foo.Count}" /> <StackPanel Grid.Column="1"> <Views: FooView2 /> </StackPanel> <Grid> FooView1: <UserControl> <TextBlock Text="{Binding Foo.Title}"> </UserControl> FooView2: <UserControl> <TextBlock Text="{Binding Foo.Detail1}"> <TextBlock Text="{Binding Foo.Detail2}"> <TextBlock Text="{Binding Foo.Detail3}"> <TextBlock Text="{Binding Foo.Detail4}"> </UserControl> I've no IDE here. Excuse me if there is any syntax error When the user clicks on a button. These two usercontrols have to be replaced by another two usercontrols, so the datacontext changes, the main ui remaining the same. ie, FooView1 by BarView1 and FooView2 by BarView2 In short i want to bind this view changes in mainview to my command (command from Button) How can i do this? Also tell me if i could merge the usercontrol pairs, so that only one view exists for each viewmodel ie, FooView1 and FooView2 into FooView and so on...

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  • C programming - How to print numbers with a decimal component using only loops?

    - by californiagrown
    I'm currently taking a basic intro to C programming class, and for our current assignment I am to write a program to convert the number of kilometers to miles using loops--no if-else, switch statements, or any other construct we haven't learned yet are allowed. So basically we can only use loops and some operators. The program will generate three identical tables (starting from 1 kilometer through the input value) for one number input using the while loop for the first set of calculations, the for loop for the second, and the do loop for the third. I've written the entire program, however I'm having a bit of a problem with getting it to recognize an input with a decimal component. Here is what I have for the while loop conversions: #include <stdio.h> #define KM_TO_MILE .62 main (void) { double km, mi, count; printf ("This program converts kilometers to miles.\n"); do { printf ("\nEnter a positive non-zero number"); printf (" of kilometers of the race: "); scanf ("%lf", &km); getchar(); }while (km <= 1); printf ("\n KILOMETERS MILES (while loop)\n"); printf (" ========== =====\n"); count = 1; while (count <= km) { mi = KM_TO_MILE * count; printf ("%8.3lf %14.3lf\n", count, mi); ++count; } getchar(); } The code reads in and converts integers fine, but because the increment only increases by 1 it won't print a number with a decimal component (e.g. 3.2, 22.6, etc.). Can someone point me in the right direction on this? I'd really appreciate any help! :)

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  • Rails load path questions

    - by HelpMe
    Say I have some custom classes that don't belong in models, controllers etc, I should put this in /lib correct? In rails < 3 I would add this directory to my loadpath and in rails 3+ I would add this to my autoload_path. Is this correct? Now say I have some classes that extends already defined classes. Where should I put this so its run on startup. Forexample say I want to add the method 'foo' on String. class String def foo 'foo; end end Where should I put this class so it's defined on startup? Another weird bug I have is when I try to namespace classes in lib. module MyProject class Foo end end Now in a console: ruby-1.9.2-p136 :004 Bags::Foo LoadError: Expected /Users/me/workspace/my_project/lib/foo.rb to define Foo from /Users/rob/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:492:in `load_missing_constant' from /Users/rob/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:183:in `block in const_missing' I keep getting this error. How can I load this file? Thanks in advance for any help!

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  • overloading "<<" with a struct (no class) cout style

    - by monkeyking
    I have a struct that I'd like to output using either 'std::cout' or some other output stream. Is this possible without using classes? Thanks #include <iostream> #include <fstream> template <typename T> struct point{ T x; T y; }; template <typename T> std::ostream& dump(std::ostream &o,point<T> p) const{ o<<"x: " << p.x <<"\ty: " << p.y <<std::endl; } template<typename T> std::ostream& operator << (std::ostream &o,const point<T> &a){ return dump(o,a); } int main(){ point<double> p; p.x=0.1; p.y=0.3; dump(std::cout,p); std::cout << p ;//how? return 0; } I tried different syntax' but I cant seem to make it work.

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  • Drools - Doing Complex Stuff inside a Rule Condition or Consequence

    - by mfcabrera
    Hello, In my company we are planning to use Drools a BRE for couple of projects. Now we trying to define some best-practices. My question is what should be and shouldn't be done inside a Rule Condition/Consequence. Given that we can write Java directly or call methods (for example From a Global object in the Working Memory). Example. Given a Rule that evaluates a generic Object (e.g. Person) have property set to true. Now, that specific propertie can only be defined for that Object going to the database and fetching that info. So we have two ways of implementing that: Alternative A: Go to the database and fetch the object property (true/false, a code) Insert the Object in the working memory Evaluate the rule Alternative B: Insert a Global Object that has a method that connects to the database and check for the property for the given object. Insert the Object to eval in Working Memory In the rule, call the Global Object and perform the access to the database Which of those is considered better? I really like A, but sometimes B is more straightforward, however what would happen if something like a Exception from the Database is raised? I have seen the alternative B implemented in the Drools 5.0 Book from Packt Publishing,however they are doing a mocking and they don't talk about the actual implications of going to the database at all. Thank you,

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  • Using static variables for Strings

    - by Vivart
    below content is taken from Best practice: Writing efficient code but i didn't understand why private static String x = "example"; faster than private static final String x ="example"; Can anybody explain this. Using static variables for Strings When you define static fields (also called class fields) of type String, you can increase application speed by using static variables (not final) instead of constants (final). The opposite is true for primitive data types, such as int. For example, you might create a String object as follows: private static final String x = "example"; For this static constant (denoted by the final keyword), each time that you use the constant, a temporary String instance is created. The compiler eliminates "x" and replaces it with the string "example" in the bytecode, so that the BlackBerry® Java® Virtual Machine performs a hash table lookup each time that you reference "x". In contrast, for a static variable (no final keyword), the String is created once. The BlackBerry JVM performs the hash table lookup only when it initializes "x", so access is faster. private static String x = "example"; You can use public constants (that is, final fields), but you must mark variables as private.

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  • Faster quadrature decoder loops with Python code

    - by Kelei
    I'm working with a BeagleBone Black and using Adafruit's IO Python library. Wrote a simple quadrature decoding function and it works perfectly fine when the motor runs at about 1800 RPM. But when the motor runs at higher speeds, the code starts missing some of the interrupts and the encoder counts start to accumulate errors. Do you guys have any suggestions as to how I can make the code more efficient or if there are functions which can cycle the interrupts at a higher frequency. Thanks, Kel Here's the code: # Define encoder count function def encodercount(term): global counts global Encoder_A global Encoder_A_old global Encoder_B global Encoder_B_old global error Encoder_A = GPIO.input('P8_7') # stores the value of the encoders at time of interrupt Encoder_B = GPIO.input('P8_8') if Encoder_A == Encoder_A_old and Encoder_B == Encoder_B_old: # this will be an error error += 1 print 'Error count is %s' %error elif (Encoder_A == 1 and Encoder_B_old == 0) or (Encoder_A == 0 and Encoder_B_old == 1): # this will be clockwise rotation counts += 1 print 'Encoder count is %s' %counts print 'AB is %s %s' % (Encoder_A, Encoder_B) elif (Encoder_A == 1 and Encoder_B_old == 1) or (Encoder_A == 0 and Encoder_B_old == 0): # this will be counter-clockwise rotation counts -= 1 print 'Encoder count is %s' %counts print 'AB is %s %s' % (Encoder_A, Encoder_B) else: #this will be an error as well error += 1 print 'Error count is %s' %error Encoder_A_old = Encoder_A # store the current encoder values as old values to be used as comparison in the next loop Encoder_B_old = Encoder_B # Initialize the interrupts - these trigger on the both the rising and falling GPIO.add_event_detect('P8_7', GPIO.BOTH, callback = encodercount) # Encoder A GPIO.add_event_detect('P8_8', GPIO.BOTH, callback = encodercount) # Encoder B # This is the part of the code which runs normally in the background while True: time.sleep(1)

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  • Getting the full-name of the current user, returns an empty string (C#/C++)

    - by Nir
    I try to get the full-name of the current log-in user (Fullname, not username). The following code C#, C++ works fine but on XP computers not connected to the Net, I get empty string as result if I run it ~20 minutes after login (It runs OK whithin the first ~20 minutes after login) A Win32 API (GetUserNameEx) is used rather that PrincipalContext since it PrincipalContext may takes up to 15 seconds when working offline. Any Help why am I getting an empty string as result though a user full name is specified??? - C# Code public static string CurrentUserFullName { get { const int EXTENDED_NAME_FORMAT_NAME_DISPLAY = 3; StringBuilder userName = new StringBuilder(256); uint length = (uint) userName.Capacity; string ret; if (GetUserNameEx(EXTENDED_NAME_FORMAT_NAME_DISPLAY, userName, ref length)) { ret = userName.ToString(); } else { int errorCode = Marshal.GetLastWin32Error(); throw new Win32Exception("GetUserNameEx Failed. Error code - " + errorCode); } return ret; } } [DllImport("Secur32.dll", CharSet = CharSet.Auto, SetLastError = true)] private static extern bool GetUserNameEx(int nameFormat, StringBuilder lpNameBuffer, ref uint lpnSize); - Code in C++ #include "stdafx.h" #include <windows.h> #define SECURITY_WIN32 #include <Security.h> #pragma comment( lib, "Secur32.lib" ) int _tmain(int argc, _TCHAR* argv[]) { char szName[100]; ULONG nChars = sizeof( szName ); if ( GetUserNameEx( NameDisplay, szName, &nChars ) ) { printf( "Name: %s\n", szName); } else { printf( "Failed to GetUserNameEx\n" ); printf( "%d\n", GetLastError() ); } return 0; }

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  • push(ing)_back objects pointers within a loop

    - by Jose Manuel Albornoz
    Consider the following: I have a class CDevices containing, amongst others, a string member class CDevice { public: CDevice(void); ~CDevice(void); // device name std::string Device_Name; etc... } and somewhere else in my code I define another class that contains a vector of pointers to CDevices class CDevice; class CServers { public: CServers(void); ~CServers(void); // Devices vector vector<CDevice*> Devices; etc... } The problem appears in the following lines in my main.c pDevice = new CDevice; pDevice->Device_Name = "de"; Devices.push_back(pDevice); pDevice->Device_Name = " revolotiunibus"; Devices.push_back(pDevice); pDevice->Device_Name = " orbium"; Devices.push_back(pDevice); pDevice->Device_Name = " coelestium"; Devices.push_back(pDevice); for(int i = 0; i < (int)Devices.size(); ++i) cout << "\nLoad name = " << Devices.at(i)->Device_Name << endl; The output I get is " coelestium" repeated four times: each time I push_back a new element into the vector all of the already existing elements take the value of the one which has just been added. I have also tried using iterators to recover each element in the vector with the same results. Could someone please tell me what's wrong here? Thankx

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  • Building Active Record Conditions in an array - private method 'scan' called error

    - by Nick
    Hi, I'm attempting to build a set of conditions dynamically using an array as suggested in the first answer here: http://stackoverflow.com/questions/1658990/one-or-more-params-in-model-find-conditions-with-ruby-on-rails. However I seem to be doing something incorrectly and I'm not sure if what I'm trying is fundamentally unsound or if I'm simply botching my syntax. I'm simplifying down to a single condition here to try to illustrate the issue as I've tried to built a simple Proof of concept along these lines before layering on the 5 different condition styles I'm contending with. This works: excluded.push 12 excluded.push 30 @allsites = Site.all(:conditions => ["id not in (?)", excluded]) This results in a private method 'scan' called error: excluded.push 12 excluded.push 30 conditionsSet << ["id not in (?)", excluded] @allsites = Site.all(:conditions => conditionsSet) Thanks for any advice. I wasn't sure if the proper thing was to put this as a followup item to the related question/answers I noted at the top. Since I've got a problem not an answer. If there is a better way to post this related to the existing post please let me know.

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  • ASP.NET: Page HTML head rendering

    - by Fabian
    I've been trying to figure out the best way to custom render the <head> element of a pag to get rid of the extra line breaks which is caused by <head runat="server">, so its properly formatted. So far the only thing i've found which works is the following: protected override void Render(HtmlTextWriter writer) { StringWriter stringWriter = new StringWriter(); HtmlTextWriter htmlTextWriter = new HtmlTextWriter(stringWriter); base.Render(htmlTextWriter); htmlTextWriter.Close(); string html = stringWriter.ToString(); string newHTML = html.Replace("\r\n\r\n<!DOCTYPE", "<!DOCTYPE") .Replace("\r\n<html", "<html") .Replace("<title>\r\n\t", "<title>") .Replace("\r\n</title>", "</title>") .Replace("</head>", "\n</head>"); writer.Write(newHTML); } I define my had tag like Now i have 2 questions: How does the above code affect the performance (so is this viable in an production environment)? Is there a better way to do this, for example a method which i can override to just custom render the <head>? Oh yeah ASP.NET MVC is not an option.

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  • c# Why can't open generic types be passed as parameters?

    - by Rich Oliver
    Why can't open generic types be passed as parameters. I frequently have classes like: public class Example<T> where T: BaseClass { public int a {get; set;} public List<T> mylist {get; set;} } Lets say BaseClass is as follows; public BaseClass { public int num; } I then want a method of say: public int MyArbitarySumMethod(Example example)//This won't compile Example not closed { int sum = 0; foreach(BaseClass i in example.myList)//myList being infered as an IEnumerable sum += i.num; sum = sum * example.a; return sum; } I then have to write an interface just to pass this one class as a parameter as follows: public interface IExample { public int a {get; set;} public IEnumerable<BaseClass> myIEnum {get;} } The generic class then has to be modified to: public class Example<T>: IExample where T: BaseClass { public int a {get; set;} public List<T> mylist {get; set;} public IEnumerable<BaseClass> myIEnum {get {return myList;} } } That's a lot of ceremony for what I would have thought the compiler could infer. Even if something can't be changed I find it psychologically very helpful if I know the reasons / justifications for the absence of Syntax short cuts.

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  • getting another website data to manipulate it's value in perl

    - by aun ali
    use CGI qw(:standard); use CGI::Carp qw(fatalsToBrowser warningsToBrowser); our @a=param(src="http://fxrates.forexpros.com/index.php?pairs_ids=1525=last_update"); print header(),start_html('results.pl'); $a=http://fxrates.forexpros.com/index.php?pairs_ids=1525=last_update; '<iframe frameborder="0" scrolling="no" height="95" width="213" allowtransparency="true" marginwidth="0" marginheight="0" src="http://fxrates.forexpros.com/index.php?pairs_ids=1525;&header-text-color=%23FFFFFF&curr-name-color=%230059b0&inner-text-color=%23000000&green-text-color=%232A8215&green-background=%23B7F4C2&red-text-color=%23DC0001&red-background=%23FFE2E2&inner-border-color=%23CBCBCB&border-color=%23cbcbcb&bg1=%23F6F6F6&bg2=%23ffffff&bid=hide&ask=hide&last=hide&high=hide&low=hide&change=hide&change_in_percents=hide&last_update=show"></iframe><br /><div style="width:213"><span style="float:left"><span style="font-size: 11px;color: #333333;text-decoration: none;">The <a href="http://www.forexpros.com/quotes" target="_blank" style="font-size: 11px;color: #06529D; font-weight: bold;" class="underline_link">Forex Quotes</a> are Powered by Forexpros - The Leading Financial Portal.</span></span></div>'; print '<br/>'; print "$a"; print end_html();' getting error: Can't modify constant item in scalar assignment at livedata.pl line 4, near ""http://fxrates.forexpros.com/index.php?pairs_ids=1525=last_update")" syntax error at livedata.pl line 6, near "http:" Execution of livedata.pl aborted due to compilation errors.

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  • How can I concisely copy multiple SQL rows, with minor modifications?

    - by Steve Jessop
    I'm copying a subset of some data, so that the copy will be independently modifiable in future. One of my SQL statements looks something like this (I've changed table and column names): INSERT Product( ProductRangeID, Name, Weight, Price, Color, And, So, On ) SELECT @newrangeid AS ProductRangeID, Name, Weight, Price, Color, And, So, On FROM Product WHERE ProductRangeID = @oldrangeid and Color = 'Blue' That is, we're launching a new product range which initially just consists of all the blue items in some specified current range, under new SKUs. In future we may change the "blue-range" versions of the products independently of the old ones. I'm pretty new at SQL: is there something clever I should do to avoid listing all those columns, or at least avoid listing them twice? I can live with the current code, but I'd rather not have to come back and modify it if new columns are added to Product. In its current form it would just silently fail to copy the new column if I forget to do that, which should show up in testing but isn't great. I am copying every column except for the ProductRangeID (which I modify), the ProductID (incrementing primary key) and two DateCreated and timestamp columns (which take their auto-generated values for the new row). Btw, I suspect I should probably have a separate join table between ProductID and ProductRangeID. I didn't define the tables. This is in a T-SQL stored procedure on SQL Server 2008, if that makes any difference.

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  • Python file iterator over a binary file with newer idiom.

    - by drewk
    In Python, for a binary file, I can write this: buf_size=1024*64 # this is an important size... with open(file, "rb") as f: while True: data=f.read(buf_size) if not data: break # deal with the data.... With a text file that I want to read line-by-line, I can write this: with open(file, "r") as file: for line in file: # deal with each line.... Which is shorthand for: with open(file, "r") as file: for line in iter(file.readline, ""): # deal with each line.... This idiom is documented in PEP 234 but I have failed to locate a similar idiom for binary files. I have tried this: >>> with open('dups.txt','rb') as f: ... for chunk in iter(f.read,''): ... i+=1 >>> i 1 # 30 MB file, i==1 means read in one go... I tried putting iter(f.read(buf_size),'') but that is a syntax error because of the parens after the callable in iter(). I know I could write a function, but is there way with the default idiom of for chunk in file: where I can use a buffer size versus a line oriented? Thanks for putting up with the Python newbie trying to write his first non-trivial and idiomatic Python script.

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  • MySQL Update query with left join and group by

    - by Rob
    I am trying to create an update query and making little progress in getting the right syntax. The following query is working: SELECT t.Index1, t.Index2, COUNT( m.EventType ) FROM Table t LEFT JOIN MEvents m ON (m.Index1 = t.Index1 AND m.Index2 = t.Index2 AND (m.EventType = 'A' OR m.EventType = 'B') ) WHERE (t.SpecialEventCount IS NULL) GROUP BY t.Index1, t.Index2 It creates a list of triplets Index1,Index2,EventCounts. It only does this for case where t.SpecialEventCount is NULL. The update query I am trying to write should set this SpecialEventCount to that count, i.e. COUNT(m.EventType) in the query above. This number could be 0 or any positive number (hence the left join). Index1 and Index2 together are unique in Table t and they are used to identify events in MEvent. How do I have to modify the select query to become an update query? I.e. something like UPDATE Table SET SpecialEventCount=COUNT(m.EventType)..... but I am confused what to put where and have failed with numerous different guesses.

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  • error catching exception while System.out.print

    - by user1702633
    I have 2 classes, one that implements a double lookup( int i); and one where I use that lookup(int i) in solving a question, or in this case printing the lookup values. This case is for an array. So I read the exception documentation or google/textbook and come with the following code: public double lookup(int i) throws Exception { if( i > numItems) throw new Exception("out of bounds"); return items[i]; } and take it over to my class and try to print my set, where set is a name of the object type I define in the class above. public void print() { for (int i = 0; i < set.size() - 1; i++) { System.out.print(set.lookup(i) + ","); } System.out.print(set.lookup(set.size())); } I'm using two print()'s to avoid the last "," in the print, but am getting an unhandled exception Exception (my exception's name was Exception) I think I have to catch my exception in my print() but cannot find the correct formatting online. Do I have to write catch exception Exception? because that gives me a syntax error saying invalid type on catch. Sources like http://docs.oracle.com/javase/tutorial/essential/exceptions/ are of little help to me, I'm can't seem to grasp what the text is telling me. I'm also having trouble finding sources with multiple examples where I can actually understand the coding in the examples. so could anybody give me a source/example for the above catch phrase and perhaps a decent source of examples for new Java programmers? my book is horrendous and I cannot seem to find an understandable example for the above catch phrase online.

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  • How to force my method to accept objects from external software?

    - by Roman
    I have a method which needs to take a callback object as an argument and then (at the moment when it's needed) my method will call a specific method of the callback object. I wrote a class called Manager which has a method called addListener. As the argument for this method I need to use a callback object which is defined by the external software. So, I define the addListener in the following way: public void addListener(Listener listener). Of course Eclipse complains because it does not know what Listener is (because the Listener is defined by the external software). The only think that I know (should know) about the Listener is that it has a method called doSomething. So, to pleasure Eclipse I add an interface before my Manager class: interface Listener { void doSomething(); } public class CTManager { ... The problem seems to be solved but then I try to test my software. So, I create a class called test. In this class I create an instance of the Manager class and try to use addListener method of this instance. I also create a class Listener, instantiate it and give the instance to the addListener. And it's the place where the problem appears. Eclipse writes that addListener is not applicable to the given argument. I think it's because it expect something from my Listenr interface but gets something from the Listener class. How can I solve this problem?

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  • Parsing CSS by regex

    - by Ross
    I'm creating a CSS editor and am trying to create a regular expression that can get data from a CSS document. This regex works if I have one property but I can't get it to work for all properties. I'm using preg/perl syntax in PHP. Regex (?<selector>[A-Za-z]+[\s]*)[\s]*{[\s]*((?<properties>[A-Za-z0-9-_]+)[\s]*:[\s]*(?<values>[A-Za-z0-9#, ]+);[\s]*)*[\s]*} Test case body { background: #f00; font: 12px Arial; } Expected Outcome Array( [0] => Array( [0] => body { background: #f00; font: 12px Arial; } [selector] => Array( [0] => body ) [1] => Array( [0] => body ) [2] => font: 12px Arial; [properties] => Array( [0] => font ) [3] => Array( [0] => font ) [values] => Array( [0] => 12px Arial [1] => background: #f00 ) [4] => Array( [0] => 12px Arial [1] => background: #f00 ) ) ) Real Outcome Array( [0] => Array ( [0] => body { background: #f00; font: 12px Arial; } [selector] => body [1] => body [2] => font: 12px Arial; [properties] => font [3] => font [values] => 12px Arial [4] => 12px Arial ) ) Thanks in advance for any help - this has been confusing me all afternoon!

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  • Rails Functional Test Failing Due to Association

    - by Koby
    I have an accounts model that holds some basic account info (account name, website, etc). I then have a user model that has the following in the app/models/user.rb belongs_to :account I also have the following in my routes.rb map.resources :account, :has_many => [:users, :othermodel] the problem I'm facing is that the following test is failing: test "should create user" do assert_difference('User.count') do post :create, :user => { } #this is the line it's actually failing on end assert_redirected_to user_path(assigns(:user)) #it doesn't get here yet end The error it gives is "Can't find Account without ID" so I kind of understand WHY it's failing, because of the fact that it doesn't have the account object (or account_id as it were) to know under what account to create the user. I have tried variations of the following but I am completely lost: post :create, :user => { accounts(:one) } #I have the 'fixtures :accounts' syntax at the top of the test class post :create, [accounts(:one), :user] => { } post :create, :user => { accounts(:one), #other params for :user } and like I said, just about every variation I could think of. I can't find much documentation on doing this and this might be why people have moved to Factories for doing test data, but I want to understand things that come standard in Rails before moving onto other things. Can anyone help me get this working?

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  • java web templates across multiple WAR files

    - by Casey
    I have a multi WAR web application that was designed badly. There is a single WAR that is responsible for handling some authorization against a database and defines a standard web page using a jsp taglib. The main WAR basically checks the privileges of the user and than based on that, displays links to the context path of the other deployed WARS. Each of the other deployed WARs includes this custom tag lib. I am working on redesigning this application, and one of the nice things that I want to retain is that we have other project teams that have developed these WAR modules that "plug into" our current system to take advantage of other things we have to offer. I am not entirely sure how to handle the page templates though. I need a templating system that would be easy enough to use across multiple wars (I was thinking of jsp fragments??). I really only need to define a consistent header and main navigation section. Whatever else is displayed on the page is up to the individual web project. Any suggestions? I hope that this is clear, if not I can elaborate more.

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  • How do I insert null fields with Perl's DBD::Pg?

    - by User1
    I have a Perl script inserting data into Postgres according to a pipe delimited text file. Sometimes, a field is null (as expected). However, Perl makes this field into an empty string and the Postgres insert statement fails. Here's a snippet of code: use DBI; #Connect to the database. $dbh=DBI-connect('dbi:Pg:dbname=mydb','mydb','mydb',{AutoCommit=1,RaiseError=1,PrintError=1}); #Prepare an insert. $sth=$dbh-prepare("INSERT INTO mytable (field0,field1) SELECT ?,?"); while (<){ #Remove the whitespace chomp; #Parse the fields. @field=split(/\|/,$_); print "$_\n"; #Do the insert. $sth-execute($field[0],$field[1]); } And if the input is: a|1 b| c|3 EDIT: Use this input instead. a|1|x b||x c|3|x It will fail at b|. DBD::Pg::st execute failed: ERROR: invalid input syntax for integer: "" I just want it to insert a null on field1 instead. Any ideas? EDIT: I simplified the input at the last minute. The old input actually made it work for some reason. So now I changed the input to something that will make the program fail. Also note that field1 is a nullable integer datatype.

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