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• Can I change my Universal App to an iPad-only app without creating a new project in XCode?

  - by user428143

  Hi there, I've created an iPad game using the Universal App Xcode template. Since I'm in late with the iPhone/iPod Touch branch of the app, I've decided to submit the app only for iPad and to update the app to universal in a second time. Question: Do I have to create a new iPad project and copy there all the code and stuff, or can I simply change the deployment target to iPad only and I'm done? I simply want to be accepted and to avoid iPhone users to be allowed to download the game erroneously. Thank you!

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• this pointer to base class constructor?

  - by Rolle

  I want to implement a derived class that should also implement an interface, that have a function that the base class can call. The following gives a warning as it is not safe to pass a this pointer to the base class constructor: struct IInterface { void FuncToCall() = 0; }; struct Base { Base(IInterface* inter) { m_inter = inter; } void SomeFunc() { inter->FuncToCall(); } IInterface* m_inter; }; struct Derived : Base, IInterface { Derived() : Base(this) {} FuncToCall() {} }; What is the best way around this? I need to supply the interface as an argument to the base constructor, as it is not always the dervied class that is the interface; sometimes it may be a totally different class. I could add a function to the base class, SetInterface(IInterface* inter), but I would like to avoid that.

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• SQL Server 2005 Transactions

  - by mcallec

  I have a long running stored proc (approx 30 mins) which is currently running within a transaction (isolation level snapshot). I've set the transaction to snapshot to avoid locking records preventing other processes from accessing the data. What I'm trying to do is write to and read from a status table, but although we're in a transaction I'd like to write to and read from the status table as if I'm not in a transaction. I need this so that other processes can read any updates to this table by my stored proc, and this stored proc can also read any inserts made by other processes. I realise that having my entire stored proc running within a transaction isn't recommended, but this has been done for other reasons and we need to stick with that approach. So my question is within a transaction, is it possible to execute a query or call a stored proc which effectively isn't enlisted in the transaction?

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• Building a jar to be used in an eclipse PDE?

  - by tul

  I have written an application that use a third party library. I have then packaged this as an executable jar using the maven-assembly-plugin (producing a jar with all dependencies including some of the third-party jars). Next I need to add this jar to a PDE project so it can be launched from eclipse. But to make this work I need to add some of the thirs-party dependencies to my PDE project which is already located in the packaged jar. So I get duplicated dependencies. Any ideas on how to avoid this? Or suggestion to documentation that describes how this is done properly?

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• How to manage member variable in C++

  - by rhapsodyn

  In brief, my question is about member variables as pointers in unmanaged C++. In java or c#, we have "advanced pointer". In fact, we can't aware the "pointer" in them. We usually initialize the member of a class like this: member = new Member(); or member = null; But in c++, it becomes more confusing. I have seen many styles: using new, or leave the member variable in stack. In my point of view, using boost::shared_ptr seems friendly, but in boost itself source code there are news everywhere. It's the matter of efficiency,isn't it? Is there a guildline like "try your best to avoid new" or something?

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• strategy to allocate/free lots of small objects

  - by aaa

  hello I am toying with certain caching algorithm, which is challenging somewhat. Basically, it needs to allocate lots of small objects (double arrays, < 256 elements), with objects accessible through mapped value, map[key] = array. time to initialized array may be quite large, generally more than 10 thousand cpu cycles. By lots I mean around gigabyte in total. objects may need to be popped/pushed as needed, generally in random places, one object at a time. lifetime of an object is generally long, minutes or more, however, object may be subject to allocation/deallocation several times during duration of program. What would be good strategy to avoid memory fragmentation, while still maintaining reasonable allocate deallocate speed? I am using C++, so I can use new and malloc. Thanks. I know there a similar questions on website, http://stackoverflow.com/questions/2156745/efficiently-allocating-many-short-lived-small-objects, are somewhat different, thread safety is not immediate issue for me.

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• Should I pointer-cast from a private derived class to its base class?

  - by skydoor

  I found this from C++FAQ Generally, No. From a member function or friend of a privately derived class, the relationship to the base class is known, and the upward conversion from PrivatelyDer* to Base* (or PrivatelyDer& to Base&) is safe; no cast is needed or recommended. However users of PrivatelyDer should avoid this unsafe conversion, since it is based on a private decision of PrivatelyDer, and is subject to change without notice. How to understand the above words? I don't think the explanation is correct or accurate. I have a code like this class A{ }; class B: private A{ }; int main(){ B *b = new B(); A *a = new A(); a = b; //wrong a = (A*)b; //right }

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• Creating audit triggers in SQL Server

  - by Mike C.

  I need to implement change tracking on two tables in my SQL Server 2005 database. I need to audit additions, deletions, updates (with detail on what was updated). I was planning on using a trigger to do this, but after poking around on Google I found that it was incredibly easy to do this incorrectly, and I wanted to avoid that on the get-go. Can anybody post an example of an update trigger that accomplishes this successfully and in an elegant manner? I am hoping to end up with an audit table with the following structure: ID LogDate TableName TransactionType (update/insert/delete) RecordID FieldName OldValue NewValue ... but I am open for suggestions. Thanks!

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• Preventing SQL injecting in a database class

  - by Josh

  I'm building a database class and thought it'd be a good idea to incorporate some form of SQL injection prevention (duh!). Here's the method that runs a database query: class DB { var $db_host = 'localhost'; var $db_user = 'root'; var $db_passwd = ''; var $db_name = 'whatever'; function query($sql) { $this->result = mysql_query($sql, $this->link); if(!$this->result) { $this->error(mysql_error()); } else { return $this->result; } } } There's more in the class than that but I'm cutting it down just for this. The problem I'm facing is if I just use mysql_real_escape_string($sql, $this->link); then it escapes the entire query and leads to a SQL syntax error. How can I dynamically find the variables that need to be escaped? I want to avoid using mysql_real_escape_string() in my main code blocks, i'd rather have it in a function. Thanks.

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• Does jquery require timestamp on GET Calls in IE7?

  - by Mithun P

  Please see the jQuery code below, it used to paginate some search results paginate: function() { $("#wishlistPage .results").html("<div id='snakeSpinner'><img src='"+BASE_URL+"images/snake.gif' title='Loading' alt='...'/></div>"); var url = BASE_URL+"wishlist/wishlist_paginated/"; $.ajax({ type: "GET", url: url, data: { sort_by:$('#componentSortOrder input:hidden').val(), offset:My.WishList.offset, per_page: 10, timestamp: new Date().getTime() }, success: function(transport){ $("#wishlistPage .results").html(transport); } }); }, My issue is not with the pagination, issue is when i need to call this same function when something happed to other part of the page which remove some search results, it brings the old results in IE7, other browsers works fine. So added the timestamp: new Date().getTime() part. That fixed the IE issue. I want o know why this happens in jQuery? Do I need to include a timestamp parameter to URL to avoid caching in all jQuery Ajax calls?

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• access a property via string with array in php?

  - by sprugman

  (This is in drupal, but I don't really think that matters.) I have a big list of properties that I need to map between two objects, and in one, the value that I need to map is buried inside an array. I'm hoping to avoid hard-coding the property names in the code. If I have a class like this: class Product { public $colors, $sizes; } I can access the properties like this: $props = array('colors', 'sizes'); foreach ($props as $p) { $this->$p = $other_object->$p; } As far as I can tell, if each of the properties on the left are an array, I can't do this: foreach ($props as $p) { $this->$p[0]['value'] = $other_object->$p; } Is that correct, or am I missing some clever way around this?

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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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• 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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• 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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• 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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• 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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• 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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• 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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• 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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• .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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• 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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• 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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• 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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