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• django shopping cart as a beginner

  - by Jacques Knie

  Hi, i'm quite new to django and trying to add a shopping cart to a simple webshop. What I need is a simple cart that can be filled and presents its content, which is then sent to the vendor via email. So Satchmo might be too big for this task. Therefore i chose django-cart (http://code.google.com/p/django-cart/) which causes some problems now. 1. Is django-cart the right thing? Or are there any better approaches to this task? 2. As I am a beginner even django-cart makes me struggle. I used the view and the template of the django-cart-website, but writing a form that can be used to add products to the cart took me hours. I probably need help in understanding the general layout of a shopping cart and its integration into a website. 3. Two more specific questions: Is it possible to dynamically populate a formfield in a template (e.g. with {{ object.id }})? Is django-cart able to change (update) the contents of a cart? I hope it's not too many questions at once. Thanks in advance Jacques

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• Should programmers do Pro Bono work? where are the code public defenders?

  - by Tj Kellie

  How many projects are people doing based on the Bro Bono publico ideals versus working for the highest wage or potential for a cash-in-buy-out payday? For years lawyers have been called out for excessive gathering of wealth from high bill rates and huge settlement deals, hiring out their knowledge and skills to the highest bidders. People call for them to do more for free, use the laws and their time to defend or further some cause thats in the public's best interest. Is professional software development that different? So many bright people and so much knowledge of complex systems. Do you think that there is enough of a "Pro Bono" movement to solve the social and public problems in the industry right now? If so what are the examples to point to? OLPC? NOTE: Saying that open source software is the same as pro bono misses the point completely. I was looking for specific projects with a social context, not just group-sourcing for free software. Just because your not making anyone pay for your software does not mean its doing anyone any good. I'm not calling out manual enforcement of pro bono work for programmers, really just want some objective opinions and concrete examples of social-minded software/tech development projects like the One Laptop Per Child project. I'm sure open source would be a natural tie-in for some.

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• Project setup for an ADO.NET/WCF DataService

  - by Slauma

  I'd like to implement a ADO.NET/WCF DataService and I am wondering what's the best way to setup a project in VS2008 SP1 for this purpose. Currently I have an ASP.NET web application project (not of "WebSite" project type). The data access layer is an Entity model (EF version 1) with SQL Server database. I have the Entity Model in a separate DLL project and the web application project references to this assembly for all data accesses. The ADO.NET/WCF DataService needs to communicate with the Entity model/database as well. It has to be hosted on the same web server (IIS 7.5) together with the web application. Since the DataService is not directly related to that specific web application (though it will provide and modify data from/in the same database the web application uses as well) my basic idea was to separate the DataService in its own new project (which also references the Entity Model DLL). Now I have seen that there is no project type "ADO.NET/WCF DataService" in VS2008 SP1. It seems only possible to add a DataService as an element to other existing projects, for instance Web Application projects. Why isn't there a separate DataService project type? Does this mean now that I have to add the DataService as an element to my Web Application project? Or shall I create a new Web Application project and add a DataService to it? (I could delete the pregenerated default.aspx since I do not need any web pages in this project.) What's the best way? Thank you for suggestions in advance!

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• Testing a method that sends e-mail without sending the mail

  - by SnOrfus

  I have a method like public abstract class Base { public void MethodUnderTest(); } public class ClassUnderTest : Base { public override MethodUnderTest() { if(condition) { IMail mail = new Mail() { /* ... */ }; IMailer mailer = new Mailer() { /* ... */ } mailer.Send(mail); } else { /* ... */ } } } I have unit tests for this method, and the mail gets sent to myself, so it's not terrible (better than no test) but I'd prefer not to send the mail. The problem I have is that I don't want test specific code in the class (ie. if (testMode) return; instead of sending the mail) I don't know lots about DI, but I considered passing a mock IMailer into MethodUnderTest except that it overrides the base class, and no other class that derives from Base needs an IMailer object (I don't want to force implementers of Base to take an unnecessary IMailer in MethodUnderTest) What else can I do? (note: IMail and IMailer are part of an external library for sending e-mail. It's written in house, so I can modify it all I like if necessary, though I can't see a need to in this situation)

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• mysql database normalization question

  - by Chocho

  here is my 3 tables: table 1 -- stores user information and it has unique data table 2 -- stores place category such as, toronto, ny, london, etc hence this is is also unique table 3 -- has duplicate information. it stores all the places a user have been. the 3 tables are linked or joined by these ids: table 1 has an "table1_id" table 2 has an "table2_id" and "place_name" table 3 has an "table3_id", "table1_id", "place_name" i have an interface where an admin sees all users. beside a user is "edit" button. clicking on that edit button allows you to edit a specific user in a form fields which has a multiple drop down box for "places". if an admin edits a user and add 1 "places" for the user, i insert that information using php. if the admin decides to deselect that 1 "places" do i delete it or mark it as on and off? how about if the admin decides to select 2 "places" for the user; change the first "places" and add an additional "places". will my table just keep growing and will i have just redundant information? thanks.

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• Asynchronous Image loading in certain custom UITableViewCells

  - by Dan

  So, I'm sure that this issue has been brought up before, but I haven't quite seen a solution for my specific problem. What I'm doing is loading a group of custom UITableViewCell's that are drawn using Loren Brichter's solution, each cell has some content, an icon (representing the user) that is asynchronously loaded into it, and a few other things. Eventually, I'm hoping to add support for images. Not every cell has an image, so in the creation of the cell, it determines if an image is required to be loaded and drawn into the cell. My problem is that I don't know how I can do that while keeping the image loaded asynchronously - with not every cell having the need to load an image (like needed with the icon) I'm not sure how to keep it in order when an cell is thrown off screen and re-rendered when the user scrolls over it. Each cell draws it content from an NSArray containing a custom object called FeedItem. All I'm really looking for is some sort of solution or idea to help me because right now I am at a loss. Thanks guys, I will appreciate the help.

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• Best Practice for Uploading Many (2000+) Images to A Server

  - by bob

  Hello, I have a general question about this. When you have a gallery, sometimes people need to upload 1000's of images at once. Most likely, it would be done through a .zip file. What is the best way to go about uploading this sort of thing to a server. Many times, server have timeouts etc. that need to be accounted for. I am wondering what kinds of things should I be looking out for and what is the best way to handle a large amount of images being uploaded. I'm guessing that you would allow a user to upload a zip file (assuming the timeout does not effect you), and this zip file is uploaded to a specific directory, lets assume in this case a directory is created for each user in the system. You would then unzip the directory on the server and scan the user's folder for any directories containing .jpg or .png or .gif files (etc.) and then import them into a table accordingly. I'm guessing labeled by folder name. What kind of server side troubles could I run into? I'm aware that there may be many issues. Even general ideas would be could so I can then research further. Thanks! Also, I would be programming in Ruby on Rails but I think this question applies accross any language.

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• Autodetect Presence of CSV Headers in a File

  - by banzaimonkey

  Short question: How do I automatically detect whether a CSV file has headers in the first row? Details: I've written a small CSV parsing engine that places the data into an object that I can access as (approximately) an in-memory database. The original code was written to parse third-party CSV with a predictable format, but I'd like to be able to use this code more generally. I'm trying to figure out a reliable way to automatically detect the presence of CSV headers, so the script can decide whether to use the first row of the CSV file as keys / column names or start parsing data immediately. Since all I need is a boolean test, I could easily specify an argument after inspecting the CSV file myself, but I'd rather not have to (go go automation). I imagine I'd have to parse the first 3 to ? rows of the CSV file and look for a pattern of some sort to compare against the headers. I'm having nightmares of three particularly bad cases in which: The headers include numeric data for some reason The first few rows (or large portions of the CSV) are null There headers and data look too similar to tell them apart If I can get a "best guess" and have the parser fail with an error or spit out a warning if it can't decide, that's OK. If this is something that's going to be tremendously expensive in terms of time or computation (and take more time than it's supposed to save me) I'll happily scrap the idea and go back to working on "important things". I'm working with PHP, but this strikes me as more of an algorithmic / computational question than something that's implementation-specific. If there's a simple algorithm I can use, great. If you can point me to some relevant theory / discussion, that'd be great, too. If there's a giant library that does natural language processing or 300 different kinds of parsing, I'm not interested.

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• Linux System Programming

  - by AJ

  I wanted to get into systems programming for linux and wanted to know how to approach that and where to begin. I come from a web development background (Python, PHP) but I also know some C and C++. Essentially, I would like to know: Which language(s) to learn and pursue (I think mainly C and C++)? How/Where to learn those languages specific to Systems Programming? Books, websites, blogs, tutorials etc. Any other good places where I can start this from basics? Any good libraries to begin with? What environment setup (or approx.) do I need? Assuming linux has to be there but I have a linux box which I rarely log into using GUI (always use SSH). Is GUI a lot more helpful or VI editor is enough? (Please let me know if this part of the question should go to serverfault.com) PS: Just to clarify, by systems programming I mean things like writing device drivers, System tools, write native applications which are not present on Linux platform but are on others, play with linux kernel etc.

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• How Does a COM Program Locate a .NET DLL Registered for COM Interop?

  - by Eric J.

  One customer wants to consume our .NET DLLs from VB6. They are designed to support reverse interop and all works fine... except: There are two separate VB6 programs in two different directories. It seems it's necessary to do one of: Copy the .NET DLL into both directories, or Install the .NET DLL in the GAC This is the customer's observation and also supported by the RegAsm documentation: After registering an assembly using Regasm.exe, you can install it in the global assembly cache so that it can be activated from any COM client. If the assembly is only going to be activated by a single application, you can place it in that application's directory. I'm confused on this point. First point of confusion: As far as I understand, the COM runtime locates the DLL using the Prog ID / Class ID. When I look in the registry at the Class ID entry, I see the full path to the .NET DLL in the CodeBase key. Why is it that a COM program using the Prog ID / Class ID doesn't locate the .NET DLL using the CodeBase? Second point of confusion: The GAC is specific to .NET. How is it involved in resolving COM references?

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• Automatically resize jQuery UI dialog to the width of the content loaded by ajax

  - by womp

  I'm having a lot of trouble finding specific information and examples on this. I've got a number of jQuery UI dialogs in my application attached to divs that are loaded with .ajax() calls. They all use the same setup call: $(".mydialog").dialog({ autoOpen: false, resizable: false, modal: true }); I just want to have the dialog resize to the width of the content that gets loaded. Right now, the width just stays at 300px (the default) and I get a horizontal scrollbar. As far as I can tell, "autoResize" is no longer an option for dialogs, and nothing happens when I specify it. I'm trying to not write a separate function for each dialog, so .dialog("option", "width", "500") is not really an option, as each dialog is going to have a different width. Specifying width: 'auto' for the dialog options just makes the dialogs take up 100% of the width of the browser window. What are my options? I'm using jQuery 1.4.1 with jQuery UI 1.8rc1. It seems like this should be something that is really easy. EDIT: I've implemented a kludgy workaround for this, but I'm still looking for a better solution.

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• Looking for Recommendations on Version Control System with Intuitive (.NET) API?

  - by John L.

  I'm working on a project which generates (composite) Microsoft Word documents which are comprised of one or more child documents. There are tens of thousands of permutations of the composite documents. Far too many for users to easily manage. Users will need to view/edit the child documents through the app which hides all of the nasty implementation details. A requirement of the system is that the child documents must be version controlled. That is what has been tripping me up. I've been torn between using an off-the-shelf solution or rolling my own. At a minimum, the system needs to support get latest, get specific version, add new, rename and possibly delete. I’ve whiteboarded it enough to realize it won’t be a trivial task to create my own. As far as commercial systems I have VSS and TFS at my disposal. I've played with the TFS API some, but it isn’t as intuitive or well documented as I had hoped. I'm not averse to an open source solution (e.g. SVN), but I have less familiarity with them. Which approach or tool would you recommend? Why? Do you have any links to API documentation you would recommend? Environment: C#, VS2008, SQL Server 2005/2008, low volume (a few hundred operations per day)

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• WCF REST with jQuery AJAX - removing/working around same origin policy

  - by csauve

  So I'm trying to create a C# WCF REST service that is called by jQuery. I've discovered that jQuery requires that AJAX calls are made under the same origin policy. I have a few questions for how I might proceed. I am already aware of; 1. The hacky solution of JSONP with a server callback 2. The way too much server overhead of having a cross-domain proxy. 3. Using Flash in the browser to make the call and setting up crossdomain.xml at my WCF server root. I'd rather not use these because; 1. I don't want to use JSON, or at least I don't want to be restricted to using it 2. I would like to separate the server that serves static pages from the one that serves application state. 3. Flash in this day in age is out of the question. What I'm thinking: is there anything like Flash's crossdomain.xml file that works for jQuery? Is this "same-origin" policy a part of jQuery or is it a restriction in specific browsers? If it's just a part of jQuery, maybe I'll try digging in the code to work around it.

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• Hibernate: Dirty Checking and Only Update of Dirty Attributes?

  - by jens

  Hello Experts, in "good old JDBC days" I wrote a lot of SQL Queries that did very targeted updates of only the "attributes/members" that were actually changed: For Example having an object with the following members: public String name; public String address; public Date date; If only date was changed in some Business Method I would only issue an SQL UPDATE for the date member. ==It seems however (thats my "impression" of hibernate) that when working with a standard Hibernate mapping (mapping the full class), even updates of only one single member lead to a full update of the object in SQL Statements generated by Hibernate. My Questions are: 1.) Is this observation correct, that hibernate DOES NOT intelligently check (in a fully mapped class), what member(s) where changed and then only issue updates for the specific changed members, but rather always will update (in the generated SQL Update Statement) all mapped members (of a class), even if they were not changed (in case the object is dirty due to one member being dirty...) 2.) What can I do to make Hibernate only update those members, that have been changed? I am searching for a solution to have hibernate only update the member that actually changed. (I know hibernate does some big work on doing dirty-checking, but as far as I know this dirtychecking is only relevant to identify if the object as whole is dirty, not what single member is dirty.) Thank you very much! Jens

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• Why does the MSCVRT library generate conflicts at link time?

  - by neuviemeporte

  I am building a project in Visual C++ 2008, which is an example MFC-based app for a static C++ class library I will be using in my own project soon. While building the Debug configuration, I get the following: warning LNK4098: defaultlib 'MSVCRT' conflicts with use of other libs; use /NODEFAULTLIB:library After using the recommended option (by adding "msvcrt" to the "Ignore specific library" field in the project linker settings for the Debug configuration), the program links and runs fine. However, I'd like to find out why this conflict occured, why do I have to ignore a critical library, and if I'm to expect problems later I if add the ignore, or what happens if I don't (because the program builds anyway). At the same time, the Release configuration warns: warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/OPT:ICF' specification warning LNK4098: defaultlib 'MSVCRTD' conflicts with use of other libs; use /NODEFAULTLIB:library I'm guessing that the "D" suffix means this is the debug version of the vc++ runtime, no idea why this gets used this time. Anyway, adding "msvcrtd" to the ignore field causes lots of link errors of the form: error LNK2001: unresolved external symbol imp_CrtDbgReportW Any insight greatly appreciated.

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• How does VS 2005 provide history across all TFS Team Projects when tf.exe cannot?

  - by AakashM

  In Visual Studio 2005, in the TFS Source Control Explorer, these is a top-level node for the TFS Server itself, with a child node for each Team Project. Right-clicking either the server node or the node for a Team Project gives a context menu on which there is a View History item. Selecting this gives you a History window showing the last 200 or so changesets, either for the specific Team Project chosen, or across all Team Projects. It is this history across all Team Projects that I am wondering about. The command-line tf.exe history command provides (as I understand it) basically the same functionality as is provided by the VS TFS Source Control plug-in. But I cannot work out how to get tf.exe history to provide this across-all-Team-Projects history. At a command line, supposing I have C:\ mapped as the root of my workspace, and Foo, Bar, and Baz as Team Projects, I can do C:\> tf history Foo /recursive /stopafter:200 to get the last 200 changesets that affected Team Project Foo; or from within a Team Project folder C:\Bar> tf history *.* /recursive /stopafter:200 which does the same thing for Team Project Bar - note that the wildcard *.* is allowed here. However, none of these work (each gives the error message shown): C:\> tf history /recursive /stopafter:200 The history command takes exactly one item C:\> tf history *.* /recursive /stopafter:200 Unable to determine the source control server C:\> tf history *.* /server:servername /recursive /stopafter:200 Unable to determine the workspace I don't see an option in the docs for tf for specifying a workspace; it seems to only want to determine it from the current folder. So what is VS 2005 doing? Is it internally doing a history on each Team Project in turn and then sticking the results together?? note also that I have tried with Power Tools; tfpt history from the command line gives exactly the same error messages seen here

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• writing a web service with dynamically determined web methods

  - by quillbreaker

  Let's say I have a text file of basic mathematical functions. I want to make a web service that answers these mathematical functions. Say the first one is y=x*x. If I wanted to turn this into a web service, I could simply do this: [WebMethod] public int A(int x) { return x*x; } However, I've extracted the function from the list by hand and coded it into a function by hand. That's not what I want to do. I want the wsdl for the service to be generated at call time directly from the text file, and I want the web method calls to the service to go to a specific method that also parses the text file at run time. How much heavy lifting is this? I've found a sample on how to generate WSDLs dynamically at this link, but there's a lot more to do beyond that and I don't want to bark up this tree if there are parts of the project that arn't feasible. Does anyone have any links, guides, books, or positive experiences trying this kind of thing?

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• SQL Agent Logon - What is going on?

  - by James Wiseman

  I have a DTSX package that is called from a SQL Agent Job. The DTSX package references a file at a fixed location (e.g. e:\mssql\myfile.txt). On most machines, this location exists, but on some I have to manually map this (which is not a problem - I know a better solution would be to use package conifgurations to dynamically pull the file location, but this is not an option here - and anyway I'd like to understand what is going on) I have set up the agent service to run as a specific user (e.g. myuser) When I log on as this user and map the directory, then run the dtsx package directly, then all goes well. When I run the package through a SQL Agent Job, the file cannot be found. If I add a command line job step to the agent job to map the drive: net use e: \\svr\location Then all works file also. So what is going on in the backgound? How come the SQL Agent user requries the drive mapping even when I am logged in as this user.

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• Newbie database index question

  - by RenderIn

  I have a table with multiple indexes, several of which duplicate the same columns: Index 1 columns: X, B, C, D Index 2 columns: Y, B, C, D Index 3 columns: Z, B, C, D I'm not very knowledgeable on indexing in practice, so I'm wondering if somebody can explain why X, Y and Z were paired with these same columns. B is an effective date. C is a semi-unique key ID for this table for a specific effective date B. D is a sequence that identifies the priority of this record for the identifier C. Why not just create 6 indexes, one for each X, Y, Z, B, C, D? I want to add an index to another column T, but in some contexts I'll only be querying on T alone while in others I will also be specifying the B, C and D columns... so should I create just one index like above or should I create one for T and one for (T, B, C, D)? I've not had as much luck as expected when googling for comprehensive coverage of indexing. Any resources where I can get a through explanation and lots of examples of B-tree indexing?

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• Should I store generated code in source control

  - by Ron Harlev

  This is a debate I'm taking a part in. I would like to get more opinions and points of view. We have some classes that are generated in build time to handle DB operations (in This specific case, with SubSonic, but I don't think it is very important for the question). The generation is set as a pre-build step in Visual Studio. So every time a developer (or the official build process) runs a build, these classes are generated, and then compiled into the project. Now some people are claiming, that having these classes saved in source control could cause confusion, in case the code you get, doesn't match what would have been generated in your own environment. I would like to have a way to trace back the history of the code, even if it is usually treated as a black box. Any arguments or counter arguments? UPDATE: I asked this question since I really believed there is one definitive answer. Looking at all the responses, I could say with high level of certainty, that there is no such answer. The decision should be made based on more than one parameter. Reading the answers below could provide a very good guideline to the types of questions you should be asking yourself when having to decide on this issue. I won't select an accepted answer at this point for the reasons mentioned above.

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• IIS 6 forces AppRoot/Starting Point to upper case when Virtual Directory is imported from a file

  - by user276464

  I have searched the web for this and couldn't find anything (well one remotely relevant post), so here I am. We have multiple ASP.NET apps in IIS 6 using Forms Authentication with dedicated path for each app. Since path is case sensitive it must match URL's path section exactly. However, because of an incorrect casing in IIS 6 Metabase for AppRoot (or Starting Point in IIS UI) bowser doesn't send Form cookie to the server whenever URL is previously resolved on the server and sent to client in incorrect case. Example: App URL = "https://Test.net/Application1" Cookie path = /Application1 Metabase AppRoot = /LM/W3SVC/1393818691/ROOT/APPLICATIONPATH1 Resolved URL = "https://Test.net/APPLICATIONPATH1" Now to the root cause... We create virtual directories on test server manually in a specific case (matches Path for each application). We then export virtual directory using UI to an XML file, which is then imported to another server (let's say production), at which point IIS decides to uppercase AppRoot element of the metabase. Can anyone shed some light on this? Is there a setting on IIS I am not aware of? I am trying to avoid manual edit of metabase after the import. Is that a bug?

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• What am I missing in IIS7?

  - by faded19

  Hello All, Ok here is my dilemma, I have been developing on a shared host at discountasp.net (IIS 6)for some time now. All was going well, however now that app is complete we are moving it to its own dedicated server which is now server 2008 and IIS 7. I am currently using asp forms authentication (which again seems to work just fine on IIS6) The issue seems to occur after I click login, it pops the "Signing In" box..an error then arises in the JavaScript of Membership.js "Object Does not Support Membership.js" I verified that the code was making it to: membership.BeginLogin(uid, pwd, rememberme); and was in fact passing the correct variables. Another odd thing I noticed when setting the forms permissions is that when I went to select Users or Roles within the IIS 7 management console it would take forever, and then time out with the following error: A Network related or instance specific error occurred while establishing a connection to SQL Server. The server was not or was not accessible, verify that the instance name is correct and that SQL Server is configured to allow remote connections (provider - named pipes provider: error 40 - could not open a connection to SQL Server.) I am rather weak on the hardware/configure side of the house so I am not really sure what the issue is, it’s almost as if IIS7 cannot see the DB. They both reside on the same server however. If anyone could help point me in the right direction as to how to resolve this I would be eternally grateful! Thanks in advance Bryan

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• Qt 4.x: how to implement drag-and-drop onto the desktop or into a folder?

  - by Jeremy Friesner

  Hi all, I've written a little file-transfer application written in C++ using Qt 4.x ... it logs into a server, shows the user a list of files available on the server, and lets the user upload or download files. This all works fine; you can even drag a file in from the desktop (or from an open folder), and when you drop the file icon into the server-files-list-view, the dropped file gets uploaded to the server. Now I have a request for the opposite action as well... my users would like to be able to drag a file out of the server-files-list-view and onto the desktop, or into an open folder window, and have that file get downloaded into that location. That seems like a reasonable request, but I don't know how to implement it. Is there a way for a Qt application to find out the directory corresponding to where "drop event" occurred, when the icon was dropped onto the desktop or into an open folder window? Ideally this would be a Qt-based platform-neutral mechanism, but if that doesn't exist, then platform-specific mechanisms for MacOS/X and Windows (XP or higher) would suffice. Any ideas?

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• Sending wordpress title-value across PHP-pages

  - by VoodooBurger

  I recently made this wordpress blog, where you can sign up a team for an event, when clicking a link under the event post. This link takes you to a sign-up form on another php-page. The link is added in the loop of the events-template like this: <?php query_posts('cat=8');?> <?php if (have_posts()) : while (have_posts()) : the_post(); ?> <div class="post" id="post-<?php the_ID(); ?>"> <h2><a href="<?php the_permalink() ?>"><?php the_title(); ?></a></h2> <div id="tilmeldknap"><?php wp_list_pages("title_li=&depth=1&include=63"); ?></div> <?php include (TEMPLATEPATH . '/inc/meta.php' ); ?>... So every upcoming event will have the same sign-up button. All I need now is to somehow send the specific event-post-title along to the sign-page, so that the following form-submit action will contain that title aswell. But since I'm not very good at php it seems like a mystery, altho I bet it's very simple! I'm guessing it's something like: $event=$_POST['single_post_title()'] But how to get the value to the next php-page I have no idea... please help, anyone :) An eksample can be seen throught this link: http://gadebold.dk/events/ The link sais: 'Tilmeld Hold'

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• haskell: a data structure for storing ascending integers with a very fast lookup

  - by valya

  Hello! (This question is related to my previous question, or rather to my answer to it.) I want to store all qubes of natural numbers in a structure and look up specific integers to see if they are perfect cubes. For example, cubes = map (\x -> x*x*x) [1..] is_cube n = n == (head $ dropWhile (<n) cubes) It is much faster than calculating the cube root, but It has complexity of O(n^(1/3)) (am I right?). I think, using a more complex data structure would be better. For example, in C I could store a length of an already generated array (not list - for faster indexing) and do a binary search. It would be O(log n) with lower ?oefficient than in another answer to that question. The problem is, I can't express it in Haskell (and I don't think I should). Or I can use a hash function (like mod). But I think it would be much more memory consuming to have several lists (or a list of lists), and it won't lower the complexity of lookup (still O(n^(1/3))), only a coefficient. I thought about a kind of a tree, but without any clever ideas (sadly I've never studied CS). I think, the fact that all integers are ascending will make my tree ill-balanced for lookups. And I'm pretty sure this fact about ascending integers can be a great advantage for lookups, but I don't know how to use it properly (see my first solution which I can't express in Haskell).

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