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  • Inheritance issue with ivar on the iPhone

    - by Buffalo
    I am using the BLIP/MYNetwork library to establish a basic tcp socket connection between the iPhone and my computer. So far, the code builds and runs correctly in simulator but deploying to device yields the following error: error: property 'delegate' attempting to use ivar '_delegate' declared in super class of 'TCPConnection' @interface TCPConnection : TCPEndpoint { @private TCPListener *_server; IPAddress *_address; BOOL _isIncoming, _checkedPeerCert; TCPConnectionStatus _status; TCPReader *_reader; TCPWriter *_writer; NSError *_error; NSTimeInterval _openTimeout; } /** The delegate object that will be called when the connection opens, closes or receives messages. */ @property (assign) id<TCPConnectionDelegate> delegate; /** The delegate messages sent by TCPConnection. All methods are optional. */ @protocol TCPConnectionDelegate <NSObject> @optional /** Called after the connection successfully opens. */ - (void) connectionDidOpen: (TCPConnection*)connection; /** Called after the connection fails to open due to an error. */ - (void) connection: (TCPConnection*)connection failedToOpen: (NSError*)error; /** Called when the identity of the peer is known, if using an SSL connection and the SSL settings say to check the peer's certificate. This happens, if at all, after the -connectionDidOpen: call. */ - (BOOL) connection: (TCPConnection*)connection authorizeSSLPeer: (SecCertificateRef)peerCert; /** Called after the connection closes. You can check the connection's error property to see if it was normal or abnormal. */ - (void) connectionDidClose: (TCPConnection*)connection; @end @interface TCPEndpoint : NSObject { NSMutableDictionary *_sslProperties; id _delegate; } - (void) tellDelegate: (SEL)selector withObject: (id)param; @end Does anyone know how I would fix this? Would I simply declare _delegate as a public property of the base class "TCPEndPoint"? Thanks for the help ya'll!

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  • window.setInterval from inside an object

    - by Keith Rousseau
    I'm currently having an issue where I have a javascript object that is trying to use setInterval to call a private function inside of itself. However, it can't find the object when I try to call it. I have a feeling that it's because window.setInterval is trying to call into the object from outside but doesn't have a reference to the object. FWIW - I can't get it to work with the function being public either. The basic requirement is that I may need to have multiple instances of this object to track multiple uploads that are occurring at once. If you have a better design than the current one or can get the current one working then I'm all ears. The following code is meant to continuously ping a web service to get the status of my file upload: var FileUploader = function(uploadKey) { var intervalId; var UpdateProgress = function() { $.get('someWebService', {}, function(json) { alert('success'); }); }; return { BeginTrackProgress: function() { intervalId = window.setInterval('UpdateProgress()', 1500); }, EndTrackProgress: function() { clearInterval(intervalId); } }; }; This is how it is being called: var fileUploader = new FileUploader('myFileKey'); fileUploader.BeginTrackProgress();

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  • Generating SQL change scripts in SSMS 2008

    - by Munish Goyal
    I have gone through many related SO threads and got some basic info. Already generated DB diagram. After that i am unable to find a button/option to generate SQL scripts (create) for all the tables in diagram. "Generate script" button is disabled, even on clicking the table in diagram. However i enabled the auto-generate option in tools-designer. But what to do with previous diagrams. I just want an easy way to auto-generate such scripts (create/alter) and would be gud if i get auto-generated stored procs for insert/selects/update etc. EDIT: I could do generate scripts for DB objects. Now: 1. How to import DB diagram from another DB. 2. How to generate (and manage their change integrated with VS source control) routine stored-procs like insert, update and select. Ok let me ask another way, can experts guide on the usual flow of creating/altering tables (across releases), creating stored-procs (are stored-procs the best way to go ?) and their change-management using SSMS design tools and minimal effort ?

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  • Passing Derived Class Instances as void* to Generic Callbacks in C++

    - by Matthew Iselin
    This is a bit of an involved problem, so I'll do the best I can to explain what's going on. If I miss something, please tell me so I can clarify. We have a callback system where on one side a module or application provides a "Service" and clients can perform actions with this Service (A very rudimentary IPC, basically). For future reference let's say we have some definitions like so: typedef int (*callback)(void*); // This is NOT in our code, but makes explaining easier. installCallback(string serviceName, callback cb); // Really handled by a proper management system sendMessage(string serviceName, void* arg); // arg = value to pass to callback This works fine for basic types such as structs or builtins. We have an MI structure a bit like this: Device <- Disk <- MyDiskProvider class Disk : public virtual Device class MyDiskProvider : public Disk The provider may be anything from a hardware driver to a bit of glue that handles disk images. The point is that classes inherit Disk. We have a "service" which is to be notified of all new Disks in the system, and this is where things unravel: void diskHandler(void *p) { Disk *pDisk = reinterpret_cast<Disk*>(p); // Uh oh! // Remainder is not important } SomeDiskProvider::initialise() { // Probe hardware, whatever... // Tell the disk system we're here! sendMessage("disk-handler", reinterpret_cast<void*>(this)); // Uh oh! } The problem is, SomeDiskProvider inherits Disk, but the callback handler can't receive that type (as the callback function pointer must be generic). Could RTTI and templates help here? Any suggestions would be greatly appreciated.

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  • How to implement generic callbacks in C++

    - by Kylotan
    Forgive my ignorance in asking this basic question but I've become so used to using Python where this sort of thing is trivial that I've completely forgotten how I would attempt this in C++. I want to be able to pass a callback to a function that performs a slow process in the background, and have it called later when the process is complete. This callback could be a free function, a static function, or a member function. I'd also like to be able to inject some arbitrary arguments in there for context. (ie. Implementing a very poor man's coroutine, in a way.) On top of that, this function will always take a std::string, which is the output of the process. I don't mind if the position of this argument in the final callback parameter list is fixed. I get the feeling that the answer will involve boost::bind and boost::function but I can't work out the precise invocations that would be necessary in order to create arbitrary callables (while currying them to just take a single string), store them in the background process, and invoke the callable correctly with the string parameter.

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  • Which source control paradigm and solution to embed in a custom editor application?

    - by Greg Harman
    I am building an application that manages a number of custom objects, which may be edited concurrently by multiple users (using different instances of the application). These objects have an underlying serialized representation, and my plan is to persist them (through my application UI) in an external source control system. Of course this implies that my application can check the current version of an object for updates, a merging interface for each object, etc. My question is what source control paradigm(s) and specific solution(s) to support and why. The way I (perhaps naively) see the source control world is three general paradigms: Single-repository, locked access (MS SourceSafe) Single-repository, concurrent access (CVS/SVN) Distributed (Mercurial, Git) I haven't heard of anyone using #1 for quite a number of years, so I am planning to disregard this case altogether (unless I get a compelling argument otherwise). However, I'm at a loss as to whether to support #2 or #3, and which specific implementations. I'm concerned that the use paradigms are subtly different enough that I can't adequately capture basic operations in a single UI. The last bit of information I should convey is that this application is intended to be deployed in a commercial setting, where a source control system may already be in use. I would prefer not to support more than one solution unless it's really a deal-breaker, so wide adoption in a corporate setting is a plus.

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  • WPF RadioButton selected in UI, but seen by code as IsChecked == false

    - by Mike
    I have some radio buttons in a group box. I select the buttons randomly, and all works perfectly from a visual standpoint and also the event handler is called each time a new button is selected. Now I have a dependency property with a callback when the value changes. When in this callback procedure I read the IsChecked value of any button, the value is False, in spite the button is visually selected (they are all false at the same time, strange). The debugger also displays all buttons unchecked. Hu hu, I'm lacking ideas about the reason, after the basic verifications... <GroupBox> <StackPanel> <RadioButton x:Name="btNone" Content="Disconnected" IsChecked="True" Checked="OnSelChecked"/> <RadioButton x:Name="btManual" Content="Manual" Checked="OnSelChecked"/> </StackPanel> </GroupBox> Event handler: private void OnSelChecked(object sender, RoutedEventArgs e) { if (btManual.IsChecked == true) { // is called } } Dependency property: public static readonly DependencyProperty ManualProperty = DependencyProperty.Register("Manual", typeof(Position), typeof(SwitchBox), new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.AffectsRender, new PropertyChangedCallback(OnManualChanged))); Dependency property callback: private static void OnManualChanged(DependencyObject sender, DependencyPropertyChangedEventArgs args) { SwitchBox box = sender as SwitchBox; if (box.btManual.IsChecked == true) { // never true, why?? } }

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  • Explaining the forecasts from an ARIMA model

    - by Samik R.
    I am trying to explain to myself the forecasting result from applying an ARIMA model to a time-series dataset. The data is from the M1-Competition, the series is MNB65. For quick reference, I have a google doc spreadsheet with the data. I am trying to fit the data to an ARIMA(1,0,0) model and get the forecasts. I am using R. Here are some output snippets: > arima(x, order = c(1,0,0)) Series: x ARIMA(1,0,0) with non-zero mean Call: arima(x = x, order = c(1, 0, 0)) Coefficients: ar1 intercept 0.9421 12260.298 s.e. 0.0474 202.717 > predict(arima(x, order = c(1,0,0)), n.ahead=12) $pred Time Series: Start = 53 End = 64 Frequency = 1 [1] 11757.39 11786.50 11813.92 11839.75 11864.09 11887.02 11908.62 11928.97 11948.15 11966.21 11983.23 11999.27 I have a few questions: (1) How do I explain that although the dataset shows a clear downward trend, the forecast from this model trends upward. This also happens for ARIMA(2,0,0), which is the best ARIMA fit for the data using auto.arima (forecast package) and for an ARIMA(1,0,1) model. (2) The intercept value for the ARIMA(1,0,0) model is 12260.298. Shouldn't the intercept satisfy the equation: C = mean * (1 - sum(AR coeffs)), in which case, the value should be 715.52. I must be missing something basic here. (3) This is clearly a series with non-stationary mean. Why is an AR(2) model still selected as the best model by auto.arima? Could there be an intuitive explanation? Thanks.

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  • Determining the color of a pixel in a bitmap using C# in a WPF app

    - by DanM
    The only way I found so far is System.Drawing.Bitmap.GetPixel(), but Microsoft has warnings for System.Drawing that are making me wonder if this is the "old way" to do it. Are there any alternatives? Here's what Microsoft says about the System.Drawing namespace. I also noticed that the System.Drawing assembly was not automatically added to the references when I created a new WPF project. System.Drawing Namespace The System.Drawing namespace provides access to GDI+ basic graphics functionality. More advanced functionality is provided in the System.Drawing.Drawing2D, System.Drawing.Imaging, and System.Drawing.Text namespaces. The Graphics class provides methods for drawing to the display device. Classes such as Rectangle and Point encapsulate GDI+ primitives. The Pen class is used to draw lines and curves, while classes derived from the abstract class Brush are used to fill the interiors of shapes. Caution Classes within the System.Drawing namespace are not supported for use within a Windows or ASP.NET service. Attempting to use these classes from within one of these application types may produce unexpected problems, such as diminished service performance and run-time exceptions. - http://msdn.microsoft.com/en-us/library/system.drawing.aspx

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  • Career Choice in JEE, are EJBs standard?

    - by John Baker
    I have chosen to go the JEE route for a career path but I have been having a hard time determining which core technologies that I need to be most familiar with. I'm at the point I can write web apps without a problem with JSP's and regular servlets using JDBC or some basic Hibernate stuff (I know, HTML, CSS and have used MVC extensively on a number of different platforms). What I'm trying to find out is if there is some standard as far as J2EE technologies go. When I look at most of the Job listings, occasionally you will see someone mention Struts or Spring but rarely do I see any mention of EJB's. So my question is really, are EJB's basically required by most JEE employers? Or are most of them working with POJO's? Is it a mix? I have a hard time figuring out if I should put the majority of my time into Struts, Spring/Hibernate, EJB's, etc. And if I do need to master EJB's what version should I learn? 2.1 or 3.0. 3.0 has some obviously better features but I figure a lot of companies probably chose to write their apps in 2.1 just because it was the standard of the time and now migrating would be a big deal. Any advice on this is greatly appreciated.

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  • Porting some PHP to ColdFusion

    - by Oscar Godson
    OK, I'm working with converting some very basic PHP to port to a dev server where the client only has CF. Ive never worked with it, and I just need to know how to port a couple things: <?php $pageTitle = 'The City That Works'; $mainCSSURL = 'header_url=../images/banner-home.jpg&amp;second_color=484848&amp;primary_color=333&amp;link_color=09c&amp;sidebar_color=f2f2f2'; require('includes/header-inc.php'); ?> I know: <cfinclude template="includes/header-inc.cfm"> but how to i get the var to be passed to the include and then how do I use it on the subsequent included file? Also in my CSS (main.php) I have (at the top): <?php header('Content-type: text/css'); foreach($_GET as $css_property => $css_value) {define(strtoupper($css_property),$css_value);} ?> and im using those constants like this: #main-content a {color:#<?= LINK_COLOR ?>;} How can I get that to work also with CF? Never thought I'd be working with CF :)

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  • The rules to connect a web service trough the SSL and Certificates

    - by blgnklc
    There is a web service running on tomcat on a server. It is built on Java Servlet. It is listening others to call itself on a SSL enabled http port. so its web service adreess looks like: https://172.29.12.12/axis/services/XYZClient?wsdl On the other hand I want to connect the web service above from a windows application which is built on .NET frame work. Finally, when I want to connect the web service from my computer; I get some specific erros; Firstly I get; Proxy authentication error; then I added some new line to my code; Dim cr As System.Net.NetworkCredential = New System.Net.NetworkCredential("xname", "xsurname", "xdomainname") Dim myProxy As New WebProxy("http://mar.xxxyyy.com", True) myProxy.Credentials = cr Secondly, after this modifications It says that bad request. I did not get over this error. Moreover I did try to connect the web server on the same computer. I copied my executable program to the computer where the web service runs. The error was like; The underlying connection was closed: Could not establish trust relationship for SSL/TLS secure channel PS: When I try to connect to web service by using Internet Explorer; I see firstly some warnings about accepting an unknown certificate and I click take me to web service an I get there clearly. I want to know what are the basic elements to connect a web service, could you please tell me the requirements that I have to use on my windows project. regards bk

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  • Would anybody recommend learning J/K/APL?

    - by ozan
    I came across J/K/APL a few months ago while working my way through some project euler problems, and was intrigued, to say the least. For every elegant-looking 20 line python solution I produced, there'd be a gobsmacking 20 character J solution that ran in a tenth of the time. I've been keen to learn some basic J, and have made a few attempts at picking up the vocabulary, but have found the learning curve to be quite steep. To those who are familiar with these languages, would you recommend investing some time to learn one (I'm thinking J in particular)? I would do so more for the purpose of satisfying my curiosity than for career advancement or some such thing. Some personal circumstances to consider, if you care to: I love mathematics, and use it daily in my work (as a mathematician for a startup) but to be honest I don't really feel limited by the tools that I use (like python + NumPy) so I can't use that excuse. I have no particular desire to work in the finance industry, which seems to be the main port of call for K users at least. Plus I should really learn C# as a next language as it's the primary language where I work. So practically speaking, J almost definitely shouldn't be the next language I learn. I'm reasonably familiar with MATLAB so using an array-based programming language wouldn't constitute a tremendous paradigm shift. Any advice from those familiar with these languages would be much appreciated.

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  • What's the most efficient way to setup a multi-lingual website

    - by Jasper De Bruijn
    Hi, I'm developing a website that will be available in different languages. It is a LAMP (Linux, Apache, MySQL, PHP) setup, and it makes use of Smarty, mostly for the template engine. The way we currently translate is by a self-written smarty plugin, which will recognize certain tags in the HTML files, and will find the corresponding tag in an earlier defined language file. The HTML could look as follows: <p>Hi, welcome to $#gamedesc;!</p> And the language file could look like this: gamedesc:Poing 2009$; welcome:this is another tag$; Which would then output <p>Hi, welcome to Poing 2009!</p> This system is very basic, but it is pretty hard to control, if I f.e. would like to keep track of what has been translated so far, or give certain users the rights to translate only certain tags. I've been looking at some alternative ways to approach this, by either replacing the text-file with XML files which could store some extra meta-data, or by perhaps storing all the texts in the database, and retrieving it there. My question is, what would be the best way to make this system both maintainable and perform well with high user-traffic? Are there perhaps any (lightweight) plugins I could take a look at?

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  • Google Maps in Drupal: reference to gmap object from JavaScript

    - by user280817
    Is there a way to obtain JavaScript references to the Google maps that are embedded into Drupal pages by the GMap module? I want to be able to manipulate the maps in these pages. I want to pan and zoom them. But I cannot find a reference to an embedded map object. I've dissected the relevant JavaScript objects Drupal.gmap and Drupal.settings.gmap with no success--unless I've overlooked something. The Drupal GMap module doesn't seem to explicitly provide references (within its API) to the GMap objects that it embeds into pages. It just generates themed text which is interpolated into the page. The technique of passing the HTML ID of the map container to either the GMap2 object constructor or the similar Drupal.gmap.getMap() function in order to obtain a map reference doesn't appear to work: Both simply return an instance to a new map, one having the same dimensions and basic characteristics of the original map, but apparently sans all of its overlays (which could contain markers). And I have to call setCenter() on it before I can use it, which initializes the structure, so I know it has no overlays.

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  • Advantages of Using Linux as primary developer desktop

    - by Nick N
    I want to get some input on some of the advantages of why developers should and need to use Linux as their primary development desktop on a daily basic as opposed to using Windows. This is particulary helpful when your Dev, QA, and Production environments are Linux. The current analogy that I keep coming back to is. If I build my demo car as a Ford Escort, but my project car is a Ford Mustang, it doesn't make sense at all. I'm currently at an IT department that allows dual boot with Windows and Linux, but some run Linux while the vast majority use Windows. Here's several advantages that I've came up with since using Linux as a primary desktop. Same Exact operating system as Dev, QA, and Production Same Scripts (.sh) instead of maintaining (.bat and *.sh). Somewhat mitigated by using cygwin, but still a bit different. Team learns simple commands such as: cd, ls, cat, top Team learns Advanced commands like: pkill, pgrep, chmod, su, sudo, ssh, scp Full access to installs typically for Linux, such as RPM, DEB installs just like the target environments. The list could go on and on, but I want to get some feedback of anything that I may have missed, or even any disadvantages (of course there are some). To me it makes sense to migrate an entire team over to using Linux, and using Virtual Box, running Windows XP VM's to test functional items that 95% of most of the world uses. This is similar but a little different thread going on here as well. link text

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  • strange chi-square result using scikit_learn with feature matrix

    - by user963386
    I am using scikit learn to calculate the basic chi-square statistics(sklearn.feature_selection.chi2(X, y)): def chi_square(feat,target): """ """ from sklearn.feature_selection import chi2 ch,pval = chi2(feat,target) return ch,pval chisq,p = chi_square(feat_mat,target_sc) print(chisq) print("**********************") print(p) I have 1500 samples,45 features,4 classes. The input is a feature matrix with 1500x45 and a target array with 1500 components. The feature matrix is not sparse. When I run the program and I print the arrray "chisq" with 45 components, I can see that the component 13 has a negative value and p = 1. How is it possible? Or what does it mean or what is the big mistake that I am doing? I am attaching the printouts of chisq and p: [ 9.17099260e-01 3.77439701e+00 5.35004211e+01 2.17843312e+03 4.27047184e+04 2.23204883e+01 6.49985540e-01 2.02132664e-01 1.57324454e-03 2.16322638e-01 1.85592258e+00 5.70455805e+00 1.34911126e-02 -1.71834753e+01 1.05112366e+00 3.07383691e-01 5.55694752e-02 7.52801686e-01 9.74807972e-01 9.30619466e-02 4.52669897e-02 1.08348058e-01 9.88146259e-03 2.26292358e-01 5.08579194e-02 4.46232554e-02 1.22740419e-02 6.84545170e-02 6.71339545e-03 1.33252061e-02 1.69296016e-02 3.81318236e-02 4.74945604e-02 1.59313146e-01 9.73037448e-03 9.95771327e-03 6.93777954e-02 3.87738690e-02 1.53693158e-01 9.24603716e-04 1.22473138e-01 2.73347277e-01 1.69060817e-02 1.10868365e-02 8.62029628e+00] ********************** [ 8.21299526e-01 2.86878266e-01 1.43400668e-11 0.00000000e+00 0.00000000e+00 5.59436980e-05 8.84899894e-01 9.77244281e-01 9.99983411e-01 9.74912223e-01 6.02841813e-01 1.26903019e-01 9.99584918e-01 1.00000000e+00 7.88884155e-01 9.58633878e-01 9.96573548e-01 8.60719653e-01 8.07347364e-01 9.92656816e-01 9.97473024e-01 9.90817144e-01 9.99739526e-01 9.73237195e-01 9.96995722e-01 9.97526259e-01 9.99639669e-01 9.95333185e-01 9.99853998e-01 9.99592531e-01 9.99417113e-01 9.98042114e-01 9.97286030e-01 9.83873717e-01 9.99745466e-01 9.99736512e-01 9.95239765e-01 9.97992843e-01 9.84693908e-01 9.99992525e-01 9.89010468e-01 9.64960636e-01 9.99418323e-01 9.99690553e-01 3.47893682e-02]

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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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  • How does a client find the port number of a server?

    - by Jonathan
    Hello all, I am currently learning about basic networking in java. I have been playing around with the server and client relationship between two of my computers. However, I cannot figure out how distributed programs (say, a videogame), can not only find the 'host' computer, but also the port number on which the server is running in order to create a Socket between the two computers. The only way I really see to create a Socket is with an already known IP Address, and with a known port number. How do you search a LAN network for another computer (host) searching for clients? How do you determine what port the server is located on without 'pinging' all available ports for a response (which, I understand, is bad form... Something about 'server attack'...)? In such a situation as a video game, there can be any number of computers on the same network, and any number of them might be attempting to host, or otherwise running the application. Any other important information, or perhaps reference to a more detailed tutorial than the one I am using, regarding making connections on so very little information on the client side would be appreciated. Many thanks, Jonathan

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  • XSLT line counter - is it that hard?

    - by Mr AH
    I have cheated every time I've needed to do a line count in XSLT by using JScript, but in this case I can't do that. I simply want to write out a line counter throughout an output file. This basic example has a simple solution: <xsl:for-each select="Records/Record"> <xsl:value-of select="position()"/> </xsl:for-each> Output would be: 1 2 3 4 etc... But what if the structure is more complex with nested foreach's : <xsl:for-each select="Records/Record"> <xsl:value-of select="position()"/> <xsl:for-each select="Records/Record"> <xsl:value-of select="position()"/> </xsl:for-each> </xsl:for-each> Here, the inner foreach would just reset the counter (so you get 1, 1, 2, 3, 2, 1, 2, 3, 1, 2 etc). Does anyone know how I can output the position in the file (ie. a line count)?

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  • What Javascript graphing package will let me plot points against a user-selected coordinate system?

    - by wes
    My customer has some specific requirements for a graph to show in our web app. We use HighCharts elsewhere in the app for more traditional graphing, but it doesn't seem to work for this situation. Their requirements: Allow the user to select a background image, set the scale and origin of the coordinate system. We'll graph our points against the user-defined coordinates. Points can be color coded Mouse-over boxes show more detail about the points Support for zooming and panning, scaling the background appropriately Less importantly: Support for drawing vectors off the points Some of this seems basic, but looking around at different graph packages, I was unable to find any with an example of this kind of usage. I've entertained the thought of just hacking it together in canvas myself, but I've never worked with canvas before so I don't think it would be cost effective. The basics of plotting points with a scaled coordinate system against an image background wouldn't be too hard, but the mouse-over details, zooming and panning sound much more daunting to me. More info: Right now we use jQuery, HighCharts, and ExtJS for our app. We tried flot in the past but switched to HighCharts after flot didn't meet our needs.

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  • How to retrieve the Description property from SettingsProperty?

    - by BadNinja
    For each item in my application's settings, I've added text to its Description Property which I want to retrieve at runtime. I'm sure I'm missing some basic logical nuance here, but everything I've tried has failed. Clearly, my understanding of what value needs to be passed to the Attributes property of the SettingsProperty class is wrong. I'm further confused by the fact that when I iterate through all they keys returned by SettingsProperty.Attributes.Keys, I can see "System.Configuration.SettingsDescriptionAttribute", but when I pass that string in as the key to the Attributes property, null is returned. Any insight into how to properly retrieve the value Description Property would be very much appreciated. Thanks. :) public void MyMethod() { SettingsPropertyCollection MyAppProperties = Properties.Settings.Default.Properties; IEnumerator enumerator = MyAppProperties.GetEnumerator(); // Iterate through all the keys to see what we have.... while (enumerator.MoveNext()) { SettingsProperty property = (SettingsProperty)enumerator.Current; ICollection myKeys = property.Attributes.Keys; foreach (object theKey in myKeys) System.Diagnostics.Debug.Print(theKey.ToString()); // One of the keys returned is: System.Configuration.SettingsDescriptionAttribute } enumerator.Reset(); while (enumerator.MoveNext()) { SettingsProperty property = (SettingsProperty)enumerator.Current; string propertyValue = property.DefaultValue.ToString(); // This fails: Null Reference string propertyDescription = property.Attributes["System.Configuration.SettingsDescriptionAttribute"].ToString(); // Do stuff with strings... } }

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  • Chrome not sending POST requests on localhost, Firefox works fine

    - by AP257
    I have copied the simple Django forms example exactly, running on localhost. The basic contact form example should submit a POST request when you click the Submit button. I'm running Chrome on Mac Snow Leopard, and whenever I submit the form, the page simply reloads with an empty form: I can see from the runserver output that it's not sending a POST - instead it's sending a GET request. If I open the same page in Firefox on Mac Snow Leopard, and submit the form, I can see it's sending a POST request (as it should be). Looking at the source in Chrome, the form definitely says method="post". <form action="/contact/" method="post"> <p><label for="id_subject">Subject:</label> <input id="id_subject" type="text" name="subject" maxlength="100" /></p> <p><label for="id_message">Message:</label> <input type="text" name="message" id="id_message" /></p> <p><label for="id_sender">Sender:</label> <input type="text" name="sender" id="id_sender" /></p> <p><label for="id_cc_myself">Cc myself:</label> <input type="checkbox" name="cc_myself" id="id_cc_myself" /></p> <input type="submit" value="Submit" /> </form> External sites with POST forms seem to work OK in Chrome. In addition, if I fill the form in incorrectly, in Chrome the page just reloads, with a GET request, as before; in Firefox the form gets validated, as it should. I've tried with other POST forms on localhost and got the same result. I know Chrome for Mac has its quirks, but what on earth is going on?

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  • What is the best approach to 2D collision detection on the iPhone?

    - by Magic Bullet Dave
    Been working on this problem of collision detection and there appears to be 3 main approaches I could take: Sprite and mask approach. (AND the overlap of the sprites and check for a non-zero number in the resulting sprite pixel data). Bounding circles, rectangles or polygons. (Create one or more shapes that enclose the sprites and do the basic maths to check for overlaps). Use an existing sprite library. The first approach, even though it would have been the way I would have done it in the old days of 16x16 sprite blocks, it appears that there just isn’t an easy way of getting at the individual image pixel data and/or alpha channel within Quartz (or OPENGL for that matter). Detecting the overlap of the bounding box is easy, but then creating a 3rd image from the overlap and then testing it for pixels is complicated and my gut feel is that even if we could get it to work would be slow. Am I missing something neat here? The second approach involves dividing up our sprites into several polygons and testing them for overlaps. The more polygons the more accurate the collision detection. The benefit is that it is fast, and can be accurate. The downside is it makes the sprite creation more complicated. i.e., we have to create the polygons for each sprite. For speed the best approach is to create a tree of polygons. The 3rd approach I’m not sure about as it involves buying code (or using an open source licence). I am not sure what the best library to use is or whether this would make life easier or give us a problem integrating this into our app. So in short I am favouring the polygon and tree approach and would appreciate you views on this before I go and write lots of code. Best regards Dave

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  • Collision detections and how efficient they are

    - by Shadow
    How exactly do you implement collision detection? What are the costs involved? Do different platforms(c/c++, java, cocoa/iphone, flash, directX) have different optimizations for calculating collisions. And lastly are there libraries available to do this for me, or some that I can just interpret for my platform of choice? As I understand it you would need to loop through the collision map and find the area in question and then compair the input thing(e.g. a sprite) to the type of pixel that is in the questioned area. I understand the very basic idea, but I don't understand the underlying implementation or even a higher level one for that matter. It would seem that this type of detection, or any for that matter, is very costly. Tile map? Bit array? How are these created from an image(I would guess looping and doing stuff)? The reason I ask this question is to get a better understanding of the efficiency behind the scenes and to understand exactly what is going on. Links, references, or examples would be very helpful. I know this question is a bit longwinded so any help or references would be very welcome. Thanks SO!

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