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• What can cause Bonjour to not call me back during browsing?

  - by millenomi

  I have a rather popular Bonjour-based application in App Store. It works perfectly, but around 0.2% of my users report a bizarre bug: "no arrows appear on the edges of the screen, so I can't share stuff with other people!". Needless to say, displaying these arrows is tied to the browsing of a particular Bonjour service on the local domain. The problem is, the Apple review team seems to intermittently happen to be in this 0.2%. This isn't good for review results, as you might imagine. No matter how much I try, I cannot reproduce this bug. From the few logs I have, it looks like my app is running correctly, just not receiving NSNetServiceBrowser delegate calls. What can cause this? Things I've tried: Having a shorter service name < 14 chars in length to be in spec. Publishing on @"local." rather than @"" (aka Go Look For The Default Registration Domain). My app is rather useless on a wide-area network anyway. Things I haven't tried: restarting the browsing machinery periodically. (I have two browsers, though, one looking for the legacy longer name, one for the new shorter one.) What to do?

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• Double Slash at end of URL when going to HTTPS?

  - by J M 4

  My site currently uses http and https sections based on the data being collected on the site (form data uses https). On my index page, I have the PHP code at the top: <?php session_start(); ob_start(); if( $_SERVER['SERVER_PORT'] == 443) { header('Location:http://'.$_SERVER['HTTP_HOST'].dirname($_SERVER['PHP_SELF'])); die(); } ?> However, the page will not load and I get a 404 error. Similarly, when i visit the sections with https security using the head code: <?php session_start(); ob_start(); if( $_SERVER['SERVER_PORT'] == 80) { header('Location:https://'.$_SERVER['HTTP_HOST'].dirname($_SERVER['PHP_SELF']).'/'.basename($_SERVER['PHP_SELF'])); die(); } ?> The site does not respond AND for some reason creates a double slash when switching from http to https. Example: http://www.abc.com/, then clicking button which should route to enroll.php shows http://www.abc.com//enroll.php why the need for the double slash and can anybody help with the 404 errors?

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• How do I do MongoDB console-style queries in PHP?

  - by Zoe Boles

  I'm trying to get a MongoDB query from the javascript console into my PHP app. What I'm trying to avoid is having to translate the query into the PHP "native driver"'s format... I don't want to hand build arrays and hand-chain functions any more than I want to manually build an array of MySQL's internal query structure just to get data. I already have a string producing the exact content I want in the Mongo console: db.intake.find({"processed": {"$exists": "false"}}).sort({"insert_date": "1"}).limit(10); The question is, is there a way for me to hand this string, as is, to MongoDB and have it return a cursor with the dataset I request? Right now I'm at the "write your own parser because it's not valid json to kinda turn a subset of valid Mongo queries into the format the PHP native driver wants" state, which isn't very fun. I don't want an ORM or a massive wrapper library; I just want to give a function my query string as it exists in the console and get an Iterator back that I can work with. I know there are a couple of PHP-based Mongo manager applications that apparently take console-style queries and handle them, but initial browsing through their code, I'm not sure how they handle the translation. I absolutely love working with mongo in the console, but I'm rapidly starting to loathe the thought of converting every query into the format the native writer wants...

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• Is there something like a Filestorage class to store files in?

  - by nebukadnezzar

  Is there something like a class that might be used to store Files and directories in, just like the way Zip files might be used? Since I haven't found any "real" class to write Zip files (real class as in real class), It would be nice to be able to store Files and Directories in a container-like file. A perfect API would probably look like this: int main() { ContainerFile cntf("myContainer.cnt", ContainerFile::CREATE); cntf.addFile("data/some-interesting-stuff.txt"); cntf.addDirectory("data/foo/"); cntf.addDirectory("data/bar/", ContainerFile::RECURSIVE); cntf.close(); } ... I hope you get the Idea. Important Requirements are: The Library must be crossplatform anything *GPL is not acceptable in this case (MIT and BSD License are) I already played with the thought of creating an Implentation based on SQLite (and its ability to store binary blobs). Unfortunately, it seems impossible to store Directory structures in a SQLite Database, which makes it pretty much useless in this case. Is it useless to hope for such a class library?

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• C++0x rvalue references and temporaries

  - by Doug

  (I asked a variation of this question on comp.std.c++ but didn't get an answer.) Why does the call to f(arg) in this code call the const ref overload of f? void f(const std::string &); //less efficient void f(std::string &&); //more efficient void g(const char * arg) { f(arg); } My intuition says that the f(string &&) overload should be chosen, because arg needs to be converted to a temporary no matter what, and the temporary matches the rvalue reference better than the lvalue reference. This is not what happens in GCC and MSVC. In at least G++ and MSVC, any lvalue does not bind to an rvalue reference argument, even if there is an intermediate temporary created. Indeed, if the const ref overload isn't present, the compilers diagnose an error. However, writing f(arg + 0) or f(std::string(arg)) does choose the rvalue reference overload as you would expect. From my reading of the C++0x standard, it seems like the implicit conversion of a const char * to a string should be considered when considering if f(string &&) is viable, just as when passing a const lvalue ref arguments. Section 13.3 (overload resolution) doesn't differentiate between rvalue refs and const references in too many places. Also, it seems that the rule that prevents lvalues from binding to rvalue references (13.3.3.1.4/3) shouldn't apply if there's an intermediate temporary - after all, it's perfectly safe to move from the temporary. Is this: Me misreading/misunderstand the standard, where the implemented behavior is the intended behavior, and there's some good reason why my example should behave the way it does? A mistake that the compiler vendors have somehow all made? Or a mistake based on common implementation strategies? Or a mistake in e.g. GCC (where this lvalue/rvalue reference binding rule was first implemented), that was copied by other vendors? A defect in the standard, or an unintended consequence, or something that should be clarified?

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• Help with accessing a pre-existing window AFTER opener is refreshed!

  - by Wilhelm Murdoch

  Alright, I'm at my wit's end on this issue. First, backstory. I'm working on a video management system where we're allowing users, when adding new content, to upload and, optionally, transcode a media file. We're using Java applet for the browser-based FTP client. What I want to do is allow a user to initiate an upload and then send the FTP connection instance to a popup window. This window will act as a job queue for the FTP transfer process. This will allow users to move about the main interface without having to stay on the original page until an individual file transfer is complete. For the most part I have all of this working, but here's a problem. If the window is closed, all connections are dropped and the upload process for all queued files will be canceled. So, if Window One opens the Popup Window, adds stuff to the queue, refreshes the screen or moves to a different page, how will I access the Popup Window? The popup window and its contents must remain persistent while the user navigates through the original window. The original window must be able to access the popup to add a new job to the queue. The popup window itself is independent of the opening window, so communication only happens in one direction: Parent - Popup Not Parent <- Popup Window.open(null, 'WINDOW_NAME'); will not work in this case. I need to check if a window exists BEFORE using window.open. Help!?!?

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• Working with datetime type in Quickbooks My Time files

  - by jakemcgraw

  I'm attempting to process Quickbooks My Time imt files using PHP. The imt file is a plaintext XML file. I've been able to use the PHP SimpleXML library with no issues but one: The numeric representations of datetime in the My Time XML files is something I've never seen before: <object type="TIMEPERIOD" id="z128"> <attribute name="notes" type="string"></attribute> <attribute name="start" type="date">308073428.00000000000000000000</attribute> <attribute name="running" type="bool">0</attribute> <attribute name="duration" type="double">3600</attribute> <attribute name="datesubmitted" type="date">310526237.59616601467132568359</attribute> <relationship name="activity" type="1/1" destination="ACTIVITY" idrefs="z130"></relationship> </object> You can see that attritube[@name='start'] has a value of: 308073428.00000000000000000000 This is not Excel based method of storage 308,073,428 is too many days since 1900-01-00 and it isn't Unix Epoch either. So, my question is, has anyone ever seen this type of datetime representation?

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• NUnit integration programmatically with spring

  - by harkon

  Hi! I have a component based architecture framework designed and I use NUnit for isolated testing - okay so far. Now I want to enable integration tests. Therefore the tests use real implementations of the existing components. Each element of the component has a life cycle (init, start and stop) and I created a NUnit component. In the start section the Console runner of the NUnit will be executed. Okay - now if I have a test fixture class in my dlls in the execution path the runner exectues them - fine! But: And this is crucial! Each to be tested implementation exists so far in the process and I want to use this instances for testing. If I use NUnit runner in the current way each instance will be created twice - and above all: I have a spring container and a implementation registry. Via this registry I can get access to all instances in the processes. But how do I give the test fixture access to the existing registry? Good: I can start the component architecture framework in the startup of the nunit runner - but this is not what I want. My guide is the apache Cactus framework (with JUnit and tomcat, JBoss etc.) Can someone help? Thanks a lot! Check: http://cone.codeplex.com

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• ASP MVC - Routing Required?

  - by evo_9

  I've been reading up on MVC2 which came in VS2010 and it sounds pretty interesting. I'm actually in the middle of a large multi-tenant application project, and have just started coding the UI. I'm considering changing to MVC as I'm not that far along at this point. I have some questions about the Routing capabilities, namely are they required to use MVC or can I more or less ignore Routing? Or do I have to setup a default routing record that will make things work like standard ASPX (as far as routing alone is concerned)? The reason why I don't want to use Routing is because I've already defined a custom URL 'rewrite' mechanism of my own (which fires on session_start). In addition, I'm using jquery and opens-standards for the entire UI, and MVC's aspx overhead-free approach seems like a better fit based on how I've already started to build the application (I am not using viewstate at all, for example). I guess my big concern is whether the routing can be ignored, of if I will have to re-implement my custom URL rewriting to work with MVC, and if that's the case, how would I do that? As a new Routing routine, or stick with the session_start (if that's even possible?). Lastly, I don't want to use anything even remotely 'intelligent/readable' for the url - for a site like StackOverflow, the readability of the URL is a positive, but the opposite is true if it's not a public website like this one. In fact, it would seem to me that the more friendly MVC routing URL (which indirectly show method names) could pose a security risk on a private, non-public website app like I'm developing. For all these reasons I would love to use the lightweight aspects of MVC but skip the Routing entirely - is this possible?

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• PHP MySQL Weird Update Problem

  - by Tim

  I have a heap based table in MySQL that I am trying to update via PHP, but for some reason, the updates do not seem to be taking place. Here is my test code: <?php $freepoints[] = 1; $freepoints[] = 2; $freepoints[] = 3; foreach ($freepoints as $entrypoint) { $query = "update gates set lane='{$entrypoint}' where traffic > 50 limit 50"; echo "$query\n"; mysql_query($query); echo mysql_affected_rows()."\n"; } ?> This outputs the following: update gates set lane='1' where traffic > 50 limit 50 50 update gates set lane='2' where traffic > 50 limit 50 50 update gates set lane='3' where traffic > 50 limit 50 50 In the database to start with lanes 1/2/3 had 0 records and lanes 4/5/6 had 100 records. From this I am expecting all 6 lanes to now have 50 records each. However when I look lanes 4/5/6 still have 100 records and 1/2/3 still have 0 records. When I copy the query "update gates set lane='1' where traffic 50 limit 50" into phpMyAdmin it works absolutely fine, so any ideas why it isn't working in my PHP script when mysql_affected_rows is saying it has updated 50 records?

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• Can't combine "LINQ Join" with other tables

  - by FullmetalBoy

  The main problem is that I recieve the following message: "base {System.SystemException} = {"Unable to create a constant value of type 'BokButik1.Models.Book-Author'. Only primitive types ('such as Int32, String, and Guid') are supported in this context."}" based on this LinQ code: IBookRepository myIBookRepository = new BookRepository(); var allBooks = myIBookRepository.HamtaAllaBocker(); IBok_ForfattareRepository myIBok_ForfattareRepository = new Bok_ForfattareRepository(); var Book-Authors = myIBok_ForfattareRepository.HamtaAllaBok_ForfattareNummer(); var q = from booknn in allBooks join Book-Authornn in Book-Authors on booknn.BookID equals Book-Authornn.BookID select new { booknn.title, Book-AuthorID }; How shall I solve this problem to get a class instance that contain with property title and Book-AuthorID? // Fullmetalboy I also have tried making some dummy by using "allbooks" relation with Code Samples from the address http://www.hookedonlinq.com/JoinOperator.ashx. Unfortunately, still same problem. I also have taken account to Int32 due to entity framework http://msdn.microsoft.com/en-us/library/bb896317.aspx. Unfortunatley, still same problem. Using database with 3 tables and one of them is a many to many relationship. This database is used in relation with entity framework Book-Author Book-Author (int) BookID (int) Forfattare (int) Book BookID (int) title (string) etc etc etc

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• Limit iPhone in-app purchase by user's country

  - by Ryan

  Hello everyone. I'm a product manager who works for a small internet company that is developing an iPhone application for a social network. We monetize by offering limited and premium memberships to users (premium members get additional features not available to limited members). For billing on the web, we use a 3rd-party payment gateway that is nearing retirement, and will be replaced by an in-house solution. The business wants a global launch for our iPhone app using iTunes + in-app purchasing as a payment gateway. The problem with going global using this payment method is that for our web service membership level, available features, and subscription costs are defined by country. For example, in the US premium/limited memberships are available at 5 pricing tiers; in France premium/limited memberships are available at 5 different pricing tiers from the US; and in Chile the service is available for free and all features are available to users. Is it possible then to have the server-side, based on the user's country of registration, control the level of access, features, and payment options for users on the iPhone? I'd also note that since iTunes Connect does not allow variable pricing by currency and country, each "region" would need 5 in app purchase options. I argued for a US-only launch for iPhone using iTunes in app purchase until an in-house payment gateway is available. But you know...

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• Setting Class-Level Variable to Use Between Event Handlers

  - by lush

  I'm having a hard time understanding why the following code doesn't work. I'm sure it's something remedial that I'm missing or not understanding. I currently have a page that asks for user input. If, based on the input and logged in user, I find data from this page already in the database, I need to update the existing records rather than creating new ones, so I set a class-level bool to true. The problem is, when MyNextButton is clicked, PreviouslySubmitted is still false. So, I'm not sure how to make the value of this variable persist. Any advice is appreciated, thanks. public partial class MyForm : System.Web.UI.Page { private bool previouslySubmitted; protected void Page_Load(object sender, EventArgs e) { MyButton.Click += (o, i) => { q = from a in db.TableA where (a.SomeField == SomeValue) select a; if(q.Any()) { PreviouslySubmitted = true; //populate the form's fields with values from database for user to revise } } MyNextButton.Click += (o, i) => { if(PreviouslySubmitted) { //update database } else { //insert into database } }

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• Scala and Java BigDecimal

  - by geejay

  I want to switch from Java to a scripting language for the Math based modules in my app. This is due to the readability, and functional limitations of mathy Java. For e.g, in Java I have this: BigDecimal x = new BigDecimal("1.1"); BigDecimal y = new BigDecimal("1.1"); BigDecimal z = x.multiply(y.exp(new BigDecimal("2")); As you can see, without BigDecimal operator overloading, simple formulas get complicated real quick. With doubles, this looks fine, but I need the precision. I was hoping in Scala I could do this: var x = 1.1; var y = 0.1; print(x + y); And by default I would get decimal-like behaviour, alas Scala doesn't use decimal calculation by default. Then I do this in Scala: var x = BigDecimal(1.1); var y = BigDecimal(0.1); println(x + y); And I still get an imprecise result. Is there something I am not doing right in Scala? Maybe I should use Groovy to maximise readability (it uses decimals by default)?

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• Why are references compacted inside Perl lists?

  - by parkan

  Putting a precompiled regex inside two different hashes referenced in a list: my @list = (); my $regex = qr/ABC/; push @list, { 'one' => $regex }; push @list, { 'two' => $regex }; use Data::Dumper; print Dumper(\@list); I'd expect: $VAR1 = [ { 'one' => qr/(?-xism:ABC)/ }, { 'two' => qr/(?-xism:ABC)/ } ]; But instead we get a circular reference: $VAR1 = [ { 'one' => qr/(?-xism:ABC)/ }, { 'two' => $VAR1->[0]{'one'} } ]; This will happen with indefinitely nested hash references and shallowly copied $regex. I'm assuming the basic reason is that precompiled regexes are actually references, and references inside the same list structure are compacted as an optimization (\$scalar behaves the same way). I don't entirely see the utility of doing this (presumably a reference to a reference has the same memory footprint), but maybe there's a reason based on the internal representation Is this the correct behavior? Can I stop it from happening? Aside from probably making GC more difficult, these circular structures create pretty serious headaches. For example, iterating over a list of queries that may sometimes contain the same regular expression will crash the MongoDB driver with a nasty segfault (see https://rt.cpan.org/Public/Bug/Display.html?id=58500)

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• I made a horrible loop.... help fix my logic please

  - by Webnet

  I know I'm doing this a bad way... but I'm having trouble seeing any alternatives. I have an array of products that I need to select 4 of randomly. $rawUpsellList is an array of all of the possible upsells based off of the items in their cart. Each value is a product object. I know this is horribly ugly code but I don't see an alternative now.... someone please put me out of my misery so this code doesn't make it to production..... $rawUpsellList = array(); foreach ($tru->global->cart->getItemList() as $item) { $product = $item->getProduct(); $rawUpsellList = array_merge($rawUpsellList, $product->getUpsellList()); } $upsellCount = count($rawUpsellList); $showItems = 4; if ($upsellCount < $showItems) { $showItems = $upsellCount; } $maxLoop = 20; $upsellList = array(); for ($x = 0; $x <= $showItems; $x++) { $key = rand(0, $upsellCount); if (!array_key_exists($key, $upsellList) && is_object($rawUpsellList[$key])) { $upsellList[$key] = $rawUpsellList[$key]; $x++; } if ($x == $maxLoop) { break; } } Posting this code was highly embarassing...

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• How to give alternating table rows different background colors using PHP

  - by Sam

  I have a table of data that is generated dynamically based on the contents stored in a mysql database. This is how my code looks: <table border="1"> <tr> <th>Name</th> <th>Description</th> <th>URL</th> </tr> <?php $query = mysql_query("SELECT * FROM categories"); while ($row = mysql_fetch_assoc($query)) { $catName = $row['name']; $catDes = $row['description']; $catUrl = $row['url']; echo "<tr class=''>"; echo "<td>$catName</td>"; echo "<td>$catDes</td>"; echo "<td>$catUrl</td>"; echo "</tr>"; } ?> </table> Now if the table was static, then I would just assign each alternating table row one of 2 styles in repeated order: .whiteBackground { background-color: #fff; } .grayBackground { background-color: #ccc; } and that would be the end of that. However since the table rows are dynamically generated, how can I achieve this?

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• Calculating a date when a date has been chosen by the number of days

  - by Andy

  I have three selection drop downs in a form comprising of day, month, year. Pretty standard. Ive omitted all the individual select options for the purposes of this question. <label for="start_date">Start Date<font class="required">*</font>:</label> <select name="place_booking[day_val]"> <select name="place_booking[month_val]"> <select name="place_booking[year_val]"> Underneath this i have a selection for the number of days the client wishes to stay at the letting. <label for="number_of_days">Number of Days<font class="required">*</font>:</label> <select name="place_booking[number_of_days]"> Underneath there is a space to display the departure date based on there two selections above. <label for="departure_date">Departure Date<font class="required">*</font>:</label> ? - this bit i would like to display the calculated date after the above is selected Any help would be grealty appreciated.

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• e4x filter on more then on childeren?

  - by Chris

  My XML Looks like this: <?xml version="1.0" encoding="utf-8" ?> <projects> <project id="1" thumb="media/images/thumb.jpg" > <categories> <id>1</id> <id>2</id> </categories> <director>Director name</director> <name><![CDATA[IPhone commercial]]></name> <url><![CDATA[http://www.iphone.com]]></url> <description><![CDATA[Description about the project]]></description> <thumb><![CDATA[/upload/images/thumb.jpg]]></thumb> </project> </projects> But I cannot figure out how to filter projects based on a category id? Does anybody know how to do ? :)

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• Lookup table size reduction

  - by Ryan

  Hello: I have an application in which I have to store a couple of millions of integers, I have to store them in a Look up table, obviously I cannot store such amount of data in memory and in my requirements I am very limited I have to store the data in an embebedded system so I am very limited in the space, so I would like to ask you about recommended methods that I can use for the reduction of the look up table. I cannot use function approximation such as neural networks, the values needs to be in a table. The range of the integers is not known at the moment. When I say integers I mean a 32 bit value. Basically the idea is use some copmpression method to reduce the amount of memory but without losing many precision. This thing needs to run in hardware so the computation overhead cannot be very high. In my algorithm I have to access to one value of the table do some operations with it and after update the value. In the end what I should have is a function which I pass an index to it and then I get a value, and after I have to use another function to write a value in the table. I found one called tile coding http://www.cs.ualberta.ca/~sutton/book/8/node6.html, this one is based on several look up tables, does anyone know any other method?. Thanks.

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• Existing parsers in c# (BSD license or similar)

  - by Sylverdrag

  I am looking for parsers (in C#) for a bunch of formats. (PHP, ASP, some XML based formats, HTML,...pretty much anything I can get my hands on.) The purpose is to separate the text from the code and do some edits without messing up the code. I had a look at ANTLR, but while it seems like the "right tool", there is just too much prior knowledge assumed. I have an easier time writing a parser from scratch than understanding how to "easily" generate parsers from ANTLR. (I wrote a small parser for a specific type of RTF files within a couple days, so the task is probably within my reach, but as I have no formal knowledge of parsing/lexing, I am at loss with ANTLR) Then it occurred to me that there must existing parsers for many formats, so before I start writing yet another a brand new and potentially buggy version of the wheel, I figured I would check what parsers already exist and can be reused in a commercial product. I could use parsers for just about every format in existence, so this question would be a good place to make a list of all existing free parsers written in C#, if there are any. Thanks in advance for your suggestions

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• What if you used the wrong language?

  - by HS

  A reply to another question made me remember a project from some years ago when it turned out that Java was not the right tool to use. I typically only learn a new language when I have a problem that it solves better than the ones I already know. [...] Then I write whatever program I wanted to learn that language for in the first place. [...] By the time I've gotten my target program written, I've usually got a decent handle on the language, not to mention any other features it has, and I've got other ideas to use it for. I did just that back then with Java, because the client thought it to be the right language to use (platform independent) and initial evaluation confirmed that. However, much later in the project there were some issue (can't really remember all the details by now). So, the project that started as a nice learning experience turned into a nightmare toward the end. I was at the brink of switching over to my trusted C++ and doing a complete rewrite. The client was not so much of a problem to convince back then, but my supervisor was strongly opposed because of all the work that already went into the Java version. In hindsight, he was right and the project was complete more or less with the intended features kind of working, but it was the project that I am least proud of by now. Long story short: what do you think, when is it too much and the switch to another technology is worthwhile? I personally would estimate the point of no return to be around 50% of the planned effort, but really want to know, if anyone has real experience with such a switch. And to answer the inevitable question: I do not really care, if the technology switched to is proven or another new thing. The latter would basically need more initial scrutiny based on the past experiences in the problematic project.

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• C# how to calculate hashcode from an object reference.

  - by Wayne

  Folks, here's a thorny problem for you! A part of the TickZoom system must collect instances of every type of object into a Dictionary< type. It is imperative that their equality and hash code be based on the instance of the object which means reference equality instead of value equality. The challenge is that some of the objects in the system have overridden Equals() and GetHashCode() for use as value equality and their internal values will change over time. That means that their Equals and GetHashCode are useless. How to solve this generically rather than intrusively? So far, We created a struct to wrap each object called ObjectHandle for hashing into the Dictionary. As you see below we implemented Equals() but the problem of how to calculate a hash code remains. public struct ObjectHandle : IEquatable<ObjectHandle>{ public object Object; public bool Equals(ObjectHandle other) { return object.ReferenceEquals(this.Object,other.Object); } } See? There is the method object.ReferenceEquals() which will compare reference equality without regard for any overridden Equals() implementation in the object. Now, how to calculate a matching GetHashCode() by only considering the reference without concern for any overridden GetHashCode() method? Ahh, I hope this give you an interesting puzzle. We're stuck over here. Sincerely, Wayne

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• JPA 2.0 Provider Hibernate

  - by Rooh

  I have very strange problem we are using jpa 2.0 with hibernate annotations based Database generated through JPA DDL is true and MySQL as Database; i will provide some reference classes and then my porblem. @MappedSuperclass public abstract class Common implements serializable{ @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "id", updatable = false) private Long id; @ManyToOne @JoinColumn private Address address; //with all getter and setters //as well equal and hashCode } @Entity public class Parent extends Common{ private String name; @OneToMany(cascade = {CascadeType.MERGE,CascadeType.PERSIST}, mappedBy = "parent") private List<Child> child; //setters and rest of class } @Entity public class Child extends Common{ //some properties with getter/setters } @Entity public class Address implements Serializable{ @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "id", updatable = false) private Long id; private String street; //rest of class with get/setter } as in code you can see that parents and child classes extends Common class so both have address property and id , the problem occurs when change the address refference in parent class it reflect same change in all child objects in list and if change address refference in child class then on merge it will change address refference of parent as well i am not able to figure out is it is problem of jpa or hibernate

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• database structure

  - by jindalsyogesh

  I have a table named ActivityRecording. This table currently has 500,000 records. I need to add a lot of new inputs that relates to activityrecording table. The relation of activityrecording with these new input fields is 1 to 0,1. So, what's going to happen on screen is when user fills the ActivityRecording data, he will then be taken to a new page and this page will show a form based on the user's input (from a dropdown named service) in activityrecording. There will 6 different kinds of form (each form will have 7-8 inputs which includes textareas of size 5kb, textboxes and checkboxes). So, for one activityrecording user will fill one out of 6 forms. There are two ways I know (there could be more), I can design the data structure: Add all the inputs from all these 6 forms into the activityrecording table. So, columns belonging to 5 of these forms will be null in this table, only columns belonging to one of the forms will have values The other way would be add 6 new tables (one for each form) and add 6 foreign key columns to activityrecording table. So, out of 6 foreign keys, 5 will be null and one will actually point to a table Which approach is a better data structure design? Please take into consideration that number of rows in this table are 500,000 and are expected to grow at a faster rate now.

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