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  • Append an onClick event to an anchor tag using jquery?

    - by M.Woodard
    I am trying to add an onClick event to an anchor tag ... Previously i had ... <a href="somlink.html" onClick="pageTracker._link(this.href); return false;"> But i am trying to avoid the inline onClick event because it interferes with another script.. So using jQuery i am trying the following code ... <script> $(document).ready(function() { $('a#tracked').attr('onClick').click(function() {window.onbeforeunload = null; pageTracker._link(this.href); return false; }); }); </script> with the html like so <a id="tracked" href="something.html"> So my question is should this be working, and if not what would be the best solution?

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  • nested has_many

    - by Nick Vanderbilt
    I am using Rails 2.3.5. Class User < ActiveRecord::Base has_many :phones end class Phone < ActiveRecord::Base has_many :frequency_bands end I want to get all the frequency_bands for a user. I know I can write a method def freq_bands for User but I would like to know if it is possible to have has_many freq_bands for a User. In this way I can chain the call. What I would like to have is class User < ActiveRecor::Base has_many :frequence_bands, :through => phones end I think it is possible to have nested has_many using this plugin http://github.com/ianwhite/nested_has_many_through However if possible I would like to avoid using another plugin and rely solely on rails.

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  • Header files in C++

    - by user269037
    Hi, I am making a simulator and have written lots of files and headers. The problem is whenever I include a file I give the relative path of the particular file. For example a typical code in my application would begin like ifndef AI_H define AI_H include include "../world/world.h" include "pathPlan.h" include "skills/tryskill.h" include "../info/condition.h" include "dataStructures/destination.h" include "../params/gamePlay.h" include "../modules/controlModule.h" class ai { public: etc etc I want to avoid using the relative paths. For example I want to directly include "tryskill.h" and "destination.h" without giving the absolute paths. That way I wont need to bother if I change the location of any particular file. I am using Ubuntu 9.10. Any help would be highly appreciated.

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  • Serializing to JSON in jQuery

    - by Herb Caudill
    I know how to serialize an object to JSON in ASP.NET Ajax, but I'm trying to do things on the client in a less Microsoft-specific way. I'm using jQuery. Is there a "standard" way to do this? My specific situation: I have an array defined something like this: var countries = new Array(); countries[0] = 'ga'; countries[1] = 'cd'; ... and I need to turn this into a string to pass to $.ajax() like this: $.ajax({ type: "POST", url: "Concessions.aspx/GetConcessions", data: "{'countries':['ga','cd']}", ... Edit (clarification) I realize there are a number of JSON libraries out there, but I'd like to avoid introducing a new dependency (if I'm going to do that, I might as well use ASP.NET Ajax's built-in JSON serializer).

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  • Sphinx without using an auto_increment id

    - by squeeks
    I am current in planning on creating a big database (2+ million rows) with a variety of data from separate sources. I would like to avoid structuring the database around auto_increment ids to help prevent against sync issues with replication, and also because each item inserted will have a alphanumeric product code that is guaranteed to be unique - it seems to me more sense to use that instead. I am looking at a search engine to index this database with Sphinx looking rather appealing due to its design around indexing relational databases. However, looking at various tutorials and documentation seems to show database designs being dependent on an auto_increment field in one form or another and a rather bold statement in the documentation saying that document ids must be 32/64bit integers only or things break. Is there a way to have a database indexed by Sphinx without auto_increment fields as the id?

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  • Select distinct ... inner join vs. select ... where id in (...)

    - by Tonio
    I'm trying to create a subset of a table (as a materialized view), defined as those records which have a matching record in another materialized view. For example, let's say I have a Users table with user_id and name columns, and a Log table, with entry_id, user_id, activity, and timestamp columns. First I create a materialized view of the Log table, selecting only those rows with timestamp some_date. Now I want a materliazed view of the Users referenced in my snapshot of the Log table. I can either create it as select * from Users where user_id in (select user_id from Log_mview), or I can do select distinct u.* from Users u inner join Log_mview l on u.user_id = l.user_id (need the distinct to avoid multiple hits from users with multiple log entries). The former seems cleaner and more elegant, but takes much longer. Am I missing something? Is there a better way to do this?

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  • try finally block around every Object.Create?

    - by max
    Hi, I have a general question about best practice in OO Delphi. Currently, I but a try finally block around everywhere, where I create an object, to free that object after usage (to avoid memory leaks). E.g.: aObject := TObject.Create; try aOBject.AProcedure(); ... finally aObject.Free; end; instead of: aObject := TObject.Create; aObject.AProcedure(); .. aObject.Free; To you think, it is good practice, or too much overhead? And what about the performance?

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  • QFileDialog used as widget

    - by lvp
    Hi! My goal is: user can choose file (only *mp3) and after clicking twice on it it should play (so the QString to file should be send to play() funtion) Firstly I started to work with QTreeView, but it has signal when the file is selected. So I decided to create QFileDialog and used it as widget built-in into MainWindow. The only problem that I have, that after double-click it dissapers. It is possible to avoid it? Should I work with some QDialog::finished() signal or, QDialog::done()?

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  • .NET DB Query Without Allocations?

    - by Michael Covelli
    I have been given the task of re-writing some libraries written in C# so that there are no allocations once startup is completed. I just got to one project that does some DB queries over an OdbcConnection every 30 seconds. I've always just used .ExecuteReader() which creates an OdbcDataReader. Is there any pattern (like the SocketAsyncEventArgs socket pattern) that lets you re-use your own OdbcDataReader? Or some other clever way to avoid allocations? I haven't bothered to learn LINQ since all the dbs at work are Oracle based and the last I checked, there was no official Linq To Oracle provider. But if there's a way to do this in Linq, I could use one of the third-party ones.

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  • Using Option all over the place feels a bit awkward. Am I doing something wrong?

    - by Geo
    As a result of articles I read about the Option class which helps you avoid NullPointerException's, I started to use it all over the place. Imagine something like this: var file:Option[File] = None and later when I use it: val actualFile = file.getOrElse(new File("nonexisting")) if(actualFile.getName.equals("nonexisting")) { // instead of null checking } else { // value of file was good } Doing stuff like this doesn't feel all that "right" to me. I also noticed that .get has become deprecated. . Is this sort of stuff what you guys are doing with Option's too, or am I going the wrong way?

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  • Get a property value with only the object and the name of the property (but not the type)

    - by Vaccano
    Suppose I have a method that passes in the name of a property (as a string) and the object that the property is on (as object). How could I get the value of the property? Here is some code to make it a bit more concrete: protected override void Paint(Graphics g, Rectangle bounds, CurrencyManager source, int rowNum, Brush backBrush, Brush foreBrush, bool alignToRight) { // The next line is made up code var currentValue = source.Current.CoolMethodToTakePropertyNameAndReturnValue(MappingName); // Paint out the retrieved value g.DrawString(currentValue.ToString() , _gridFont, new SolidBrush(Color.Black), bounds.Left + 1, bounds.Top); } MappingName is the name of the property I want to get the value for. What I need is CoolMethodToTakePropertyNameAndReturnValue. Any ideas? I am running on the Compact Framework. I would also prefer to avoid reflection (but if that is my only recourse then so be it). Thanks for any help.

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  • Does C# 4's covariance support nesting of generics?

    - by Scott Bilas
    I don't understand why 'x' below converts, but 'y' and 'z' do not. var list = new List<List<int>>(); IEnumerable<List<int>> x = list; List<IEnumerable<int>> y = list; IEnumerable<IEnumerable<int>> z = list; Does the new covariance feature simply not work on generics of generics or am I doing something wrong? (I'd like to avoid using .Cast< to make y and z work.)

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  • Why Do try ... catch Blocks Require Braces?

    - by Bidou
    Hello. While in other statements like if ... else you can avoid braces if there is only one instruction in a block, you cannot do that with try ... catch blocks: the compiler doesn't buy it. For instance: try do_something_risky(); catch (...) std::cerr << "Blast!" << std::endl; With the code above, g++ simply says it expects a '{' before do_something_risky(). Why this difference of behavior between try ... catch and, say, if ... else ? Thanks!

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  • Make SQL query more efficient

    - by Webnet
    I currently have this query which runs 2 of the exact same sub queries but pull different data. When I make the values comma separated it throws an SQL error saying the sub query can return only one value. Is there anything else I can do to avoid running multiple sub queries? SELECT product_id, ( SELECT COUNT(listing_id) FROM ebay_archive_product_listing_assoc WHERE product_id = product_master.product_id) as listing_count, sku, type_id, ( SELECT AVG(ebay_archive_listing.current_price), AVG(ebay_archive_listing.buy_it_now_price) FROM ebay_archive_listing WHERE id IN ( SELECT listing_id FROM ebay_archive_product_listing_assoc WHERE product_id = product_master.product_id ) AND ebay_archive_listing.start_time >= '.$startTimestamp.' AND ebay_archive_listing.start_time <= '.$endTimestamp.' AND ebay_archive_listing.current_price > 0 ) as average_bid_price, ( SELECT FROM ebay_archive_listing WHERE id IN ( SELECT listing_id FROM ebay_archive_product_listing_assoc WHERE product_id = product_master.product_id ) AND ebay_archive_listing.start_time >= '.$startTimestamp.' AND ebay_archive_listing.start_time <= '.$endTimestamp.' AND ebay_archive_listing.buy_it_now_price > 0 ) as average_buyout_price FROM product_master I'm aware of the syntax error... I'm selecting 2 seperate averages and am wondering if I can do it any simpler way.

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  • C++ vector that *doesn't* initialize its members?

    - by Mehrdad
    I'm making a C++ wrapper for a piece of C code that returns a large array, and so I've tried to return the data in a vector<unsigned char>. Now the problem is, the data is on the order of megabytes, and vector unnecessarily initializes its storage, which essentially turns out to cut down my speed by half. How do I prevent this? Or, if it's not possible -- is there some other STL container that would avoid such needless work? Or must I end up making my own container? (Pre-C++11) Note: I'm passing the vector as my output buffer. I'm not copying the data from elsewhere.

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  • C#: Using as bool? instead of object something = ViewState["hi"]

    - by Programmin Tool
    So I'm going through old code (2.0) and I came across this: object isReviewingValue = ViewState["IsReviewing"]; if (isReviewingValue is bool) { return (bool)isReviewingValue; } My first thought was to us the "as" keyword to avoid the unneeded (bool)isReviewingValue; But "as" only works with non value types. No problem, I just went ahead and did this: bool? isReviewingValue= ViewState["IsReviewing"] as bool?; if (isReviewingValue.HasValue) { return isReviewingValue.Value; } Question is: Besides looking a bit more readable, is this in fact better?

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  • memory management question -- releasing an object which has to be returned

    - by ulag
    Hi, I have an NSMutableArray called playlist. This is in a method called getAllPlaylists. The code is something like this: -(NSMutableArray *)getAllPlaylists { //playlist is an instance variable playlist = [[NSMutableArray alloc] init]; //memory leak here . . //some code here which populates the playlist array [playlist addObject: object1]; . . return playlist; } The array allocation step of playlist is causing a memory leak. In such a scenario where can i release this array? Or can i avoid allocation n initialization of playlist here by doing something else?

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  • Simplifying CASE WHEN SQL statement

    - by kateroh
    Im trying to improve the following CASE statement to calculate the difference only once. I do it to avoid negative numbers: SELECT (CASE WHEN ((SELECT 100 - (SELECT COUNT(CustomerId) FROM Customers)) > 0) THEN (SELECT 100 - (SELECT COUNT(CustomerId) FROM Customers)) ELSE (0) END) This not only looks stupid, but also is not thread-safe. I tried the following, but I get an error message "Invalid column name 'diff'." SELECT (CASE WHEN ((SELECT 100 - (SELECT COUNT(CustomerId) FROM Customers) as diff) > 0) THEN (diff) ELSE (0) END) How can this be simplified? Is there an in-built SQL function that already does this job? EDIT: Sorry, forgot to mention that the select statement is inside of a view declaration, so I cant declare variables.

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  • nested has_many

    - by dorelal
    I am using Rails 2.3.5. Class User < ActiveRecord::Base has_many :phones end class Phone < ActiveRecord::Base has_many :frequency_bands end I want to get all the frequency_bands for a user. I know I can write a method def freq_bands for User but I would like to know if it is possible to have has_many freq_bands for a User. In this way I can chain the call. What I would like to have is class User < ActiveRecor::Base has_many :frequence_bands, :through => phones end I think it is possible to have nested has_many using this plugin http://github.com/ianwhite/nested_has_many_through However if possible I would like to avoid using another plugin and rely solely on rails.

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  • How can a Perl force its caller to return? [closed]

    - by JS Bangs
    Possible Duplicate: Is it possible for a Perl subroutine to force its caller to return? I want to write a subroutine which causes the caller to return under certain conditions. This is meant to be used as a shortcut for validating input to a function. What I have so far is: sub needs($$) { my ($condition, $message) = @_; if (not $condition) { print "$message\n"; # would like to return from the *parent* here } return $condition; } sub run_find { my $arg = shift @_; needs $arg, "arg required" or return; needs exists $lang{$arg}, "No such language: $arg" or return; # etc. } The advantage of returning from the caller in needs would then be to avoid having to write the repetitive or return inside run_find and similar functions.

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  • Why do dicts of defaultdict(int)'s use so much memory? (and other simple python performance question

    - by dukhat
    import numpy as num from collections import defaultdict topKeys = range(16384) keys = range(8192) table = dict((k,defaultdict(int)) for k in topKeys) dat = num.zeros((16384,8192), dtype="int32") print "looping begins" #how much memory should this use? I think it shouldn't use more that a few #times the memory required to hold (16384*8192) int32's (512 mb), but #it uses 11 GB! for k in topKeys: for j in keys: dat[k,j] = table[k][j] print "done" What is going on here? Furthermore, this similar script takes eons to run compared to the first one, and also uses an absurd quantity of memory. topKeys = range(16384) keys = range(8192) table = [(j,0) for k in topKeys for j in keys] I guess python ints might be 64 bit ints, which would account for some of this, but do these relatively natural and simple constructions really produce such a massive overhead? I guess these scripts show that they do, so my question is: what exactly is causing the high memory usage in the first script and the long runtime and high memory usage of the second script and is there any way to avoid these costs?

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  • An NSMutableArray that doesn't retain?

    - by synic
    A few UIViewControllers in my app that need to register with a "provider" class in their viewDidLoad methods. I've just been adding them to an NSMutableArray contained in the provider class. However, I don't want this NSMutableArray to keep them from being dealloc'ed, and I also want to have them remove themselves from the NSMutableArray in their dealloc methods. I tried just issuing a [self release] after adding them to the array, and this works, but in order to avoid a crash when they get dealloc'ed, I have to issue a [self retain] right before I remove them. It seems like I'm doing something horribly wrong by retaining an object in it's own dealloc method. Is there a better way to store these values?

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  • Shoud a method that waits for a change of state be const?

    - by Space_C0wb0y
    In a multithreaded scenario, I have a method like this: bool WaitForChange( time_duration WaitTime ) const; This method waits either until the state of the object has changed and returns true, or until the timeout times out (how do you say that?) and returns false. My intuition is, that const is to protect against unwanted side-effects of the method itself, so this is fine. But then again, some user might think that the state of the could not have changed, since the method is declared const. Is that user stupid, or should I make the method non-const in order to avoid confusion?

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  • C++ Reading and Editing pixels of a bitmap image

    - by BettyD
    I'm trying to create a program which reads an image in (starting with bitmaps because they're the easiest), searches through the image for a particular parameter (i.e. one pixel of (255, 0, 0) followed by one of (0, 0, 255)) and changes the pixels in some way (only within the program, not saving to the original file.) and then displays it. I'm using Windows, simple GDI for preference and I want to avoid custom libraries just because I want to really understand what I'm doing for this test program. Can anyone help? In any way? A website? Advice? Example code? Thanks

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