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• Which design is better (OO Design)?

  - by Tattat

  I have an "Enemy" object, that have many "gun" . Each "gun" can fire "bullet". Storing "gun" is using an array. when the "gun" is fired, the "bullet" will be created. And the enemy object will have an array to store the "bullet". So, I am thinking about the fire method. I am think making a firebulletFromGun in the "enemy". It need have a parameter: "gun". while this method is called. The "enemy" 's bullet will be added in the Array. Another design is writing the fire method in the "gun". The "enemy" use the "gun"'s fire method. And the "gun" will return a "bullet" object, and it will be added in the Array of "enemy". Both method can work, but which way is better? or they are similar the same? plx drop ur ideas/suggestions. thz.

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• How to have multiple instances of jQuery plugin on single page?

  - by James Skidmore

  I'm writing a simple jQuery plugin, but I'm having trouble being able to use multiple instances on a page. For instance, here is a sample plugin to illustrate my point: (function($) { $.fn.samplePlugin = function(options) { if (typeof foo != 'undefined') { alert('Already defined!'); } else { var foo = 'bar'; } }; })(jQuery); And then if I do this: $(document).ready(function(){ $('#myDiv').samplePlugin({}); // does nothing $('#myDiv2').samplePlugion({}); // alerts "Already defined!" }); This is obviously an over-simplified example to get across the point. So my question is, how do I have two separate instances of the plugin? I'd like to be able to use it across multiple instances on the same page. I'm guessing that part of the problem might be with defining the variables in a global scope. How can I define them unique to that instance of the plugin then? Thank you for your guidance!

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• Given a typical Rails 3 environment, why am I unable to execute any tests?

  - by Tom

  I'm working on writing simple unit tests for a Rails 3 project, but I'm unable to actually execute any tests. Case in point, attempting to run the test auto-generated by Rails fails: require 'test_helper' class UserTest < ActiveSupport::TestCase # Replace this with your real tests. test "the truth" do assert true end end Results in the following error: <internal:lib/rubygems/custom_require>:29:in `require': no such file to load -- test_helper (LoadError) from <internal:lib/rubygems/custom_require>:29:in `require' from user_test.rb:1:in `<main>' Commenting out the require 'test_helper' line and attempting to run the test results in this error: user_test.rb:3:in `<main>': uninitialized constant Object::ActiveSupport (NameError) The action pack gems appear to be properly installed and up to date: actionmailer (3.0.3, 2.3.5) actionpack (3.0.3, 2.3.5) activemodel (3.0.3) activerecord (3.0.3, 2.3.5) activeresource (3.0.3, 2.3.5) activesupport (3.0.3, 2.3.5) Ruby is at 1.9.2p0 and Rails is at 3.0.3. The sample dump of my test directory is as follows: /fixtures /functional /integration /performance /unit -- /helpers -- user_helper_test.rb -- user_test.rb test_helper.rb I've never seen this problem before - I've run the typical rake tasks for preparing the test environment. I have nothing out of the ordinary in my application or environment configuration files, nor have I installed any unusual gems that would interfere with the test environment. Edit Xavier Holt's suggestion, explicitly specifying the path to the test_helper worked; however, this revealed an issue with ActiveSupport. Now when I attempt to run the test, I receive the following error message (as also listed above): user_test.rb:3:in `<main>': uninitialized constant Object::ActiveSupport (NameError) But as you can see above, Action Pack is all installed and update to date.

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• Binding ComboBoxes to enums... in Silverlight!

  - by Domenic

  So, the web, and StackOverflow, have plenty of nice answers for how to bind a combobox to an enum property in WPF. But Silverlight is missing all of the features that make this possible :(. For example: You can't use a generic EnumDisplayer-style IValueConverter that accepts a type parameter, since Silverlight doesn't support x:Type. You can't use ObjectDataProvider, like in this approach, since it doesn't exist in Silverlight. You can't use a custom markup extension like in the comments on the link from #2, since markup extensions don't exist in Silverlight. You can't do a version of #1 using generics instead of Type properties of the object, since generics aren't supported in XAML (and the hacks to make them work all depend on markup extensions, not supported in Silverlight). Massive fail! As I see it, the only way to make this work is to either Cheat and bind to a string property in my ViewModel, whose setter/getter does the conversion, loading values into the ComboBox using code-behind in the View. Make a custom IValueConverter for every enum I want to bind to. Are there any alternatives that are more generic, i.e. don't involve writing the same code over and over for every enum I want? I suppose I could do solution #2 using a generic class accepting the enum as a type parameter, and then create new classes for every enum I want that are simply class MyEnumConverter : GenericEnumConverter<MyEnum> {} What are your thoughts, guys?

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• How to implement a 'safe' periodical executer without using the Rails helpers?

  - by Robbie

  I am very new to Ruby on Rails and was never really big on writing JavaScript, so the built in helpers were like a tiny silce of heaven. However I have recently learned that using the helper methods creates "obtrusive javascript" so I am doing a tiny bit of refactoring to get all this messy code out of my view. I'm also using the Prototype API to figure out what all these functions do. Right now, I have: <%= periodically_call_remote(:url => {:action => "tablerefresh", :id => 1 }, :frequency => '5', :complete => "load('26', 'table1', request.responseText)")%> Which produces: <script type="text/javascript"> //<![CDATA[ new PeriodicalExecuter(function() {new Ajax.Request('/qrpsdrail/grids/tablerefresh/1', {asynchronous:true, evalScripts:true, onComplete:function(request){load('26', 'table1', request.responseText)}, parameters:'authenticity_token=' + encodeURIComponent('dfG7wWyVYEpelfdZvBWk7MlhzZoK7VvtT/HDi3w7gPM=')})}, 5) //]]> </script> My concern is that the "encodeURIComponent" and the presence of "authenticity_token" are generated by Rails. I'm assuming these are used to assure the validity of a request. (Ensuring a request comes from a currently active session?) If that is the case, how can I implement this in application.js 'safely'? It seems that the built in method, although obtrusive, does add some beneficial security. Thanks, in advance, to all who answer.

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• Convert SQL to LINQ in MVC3 with Ninject

  - by Jeff

  I'm using MVC3 and still learning LINQ. I'm having some trouble trying to convert a query to LINQ to Entities. I want to return an employee object. SELECT E.EmployeeID, E.FirstName, E.LastName, MAX(EO.EmployeeOperationDate) AS "Last Operation" FROM Employees E INNER JOIN EmployeeStatus ES ON E.EmployeeID = ES.EmployeeID INNER JOIN EmployeeOperations EO ON ES.EmployeeStatusID = EO.EmployeeStatusID INNER JOIN Teams T ON T.TeamID = ES.TeamID WHERE T.TeamName = 'MyTeam' GROUP BY E.EmployeeID, E.FirstName, E.LastName ORDER BY E.FirstName, E.LastName What I have is a few tables, but I need to get only the newest status based on the EmployeeOpertionDate. This seems to work fine in SQL. I'm also using Ninject and set my query to return Ienumerable. I played around with the group by option but it then returns IGroupable. Any guidance on converting and returning the property object type would be appreciated. Edit: I started writing this out in LINQ but I'm not sure how to properly return the correct type or cast this. public IQueryable<Employee> GetEmployeesByTeam(int teamID) { var q = from E in context.Employees join ES in context.EmployeeStatuses on E.EmployeeID equals ES.EmployeeID join EO in context.EmployeeOperations on ES.EmployeeStatusID equals EO.EmployeeStatusID join T in context.Teams on ES.TeamID equals T.TeamID where T.TeamName == "MyTeam" group E by E.EmployeeID into G select G; return q; } Edit2: This seems to work for me public IQueryable<Employee> GetEmployeesByTeam(int teamID) { var q = from E in context.Employees join ES in context.EmployeeStatuses on E.EmployeeID equals ES.EmployeeID join EO in context.EmployeeOperations.OrderByDescending(eo => eo.EmployeeOperationDate) on ES.EmployeeStatusID equals EO.EmployeeStatusID join T in context.Teams on ES.TeamID equals T.TeamID where T.TeamID == teamID group E by E.EmployeeID into G select G.FirstOrDefault(); return q; }

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• How to download a file from a UNC mapped share via IIS and ASP

  - by helgeg

  I am writing an ASP application that will serve files to clients through the browser. The files are located on a file server that is available from the machine IIS is running on via a UNC path (\server\some\path). I want to use something like the code below to serve the file. Serving files that are local to the machine IIS is running on is working well with this method, my trouble is being able to serve files from the UNC mapped share: //Set the appropriate ContentType. Response.ContentType = "Application/pdf"; //Get the physical path to the file. string FilePath = MapPath("acrobat.pdf"); //Write the file directly to the HTTP content output stream. Response.WriteFile(FilePath); Response.End(); My question is how I can specify a UNC path for the file name. Also, to access the file share I need to connect with a specific username/password. I would appreciate some pointers on how I can achieve this (either using the approach above or by other means).

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• TicTacToe strategic reduction

  - by NickLarsen

  I decided to write a small program that solves TicTacToe in order to try out the effect of some pruning techniques on a trivial game. The full game tree using minimax to solve it only ends up with 549,946 possible games. With alpha-beta pruning, the number of states required to evaluate was reduced to 18,297. Then I applied a transposition table that brings the number down to 2,592. Now I want to see how low that number can go. The next enhancement I want to apply is a strategic reduction. The basic idea is to combine states that have equivalent strategic value. For instance, on the first move, if X plays first, there is nothing strategically different (assuming your opponent plays optimally) about choosing one corner instead of another. In the same situation, the same is true of the center of the walls of the board, and the center is also significant. By reducing to significant states only, you end up with only 3 states for evaluation on the first move instead of 9. This technique should be very useful since it prunes states near the top of the game tree. This idea came from the GameShrink method created by a group at CMU, only I am trying to avoid writing the general form, and just doing what is needed to apply the technique to TicTacToe. In order to achieve this, I modified my hash function (for the transposition table) to enumerate all strategically equivalent positions (using rotation and flipping functions), and to only return the lowest of the values for each board. Unfortunately now my program thinks X can force a win in 5 moves from an empty board when going first. After a long debugging session, it became apparent to me the program was always returning the move for the lowest strategically significant move (I store the last move in the transposition table as part of my state). Is there a better way I can go about adding this feature, or a simple method for determining the correct move applicable to the current situation with what I have already done?

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• Vim - show diff on commit in mercurial;

  - by JackLeo

  In my .hgrc I can provide an editor or a command to launch an editor with options on commit. I want to write a method or alias that launches $ hg ci, it would not only open up message in Vim, but also would split window and there print out $ hg diff. I know that I can give parameters to vim by using +{command} option. So launching $ vim "+vsplit" does the split but any other options goes to first opened window. So I assume i need a specific function, yet I have no experience in writing my own Vim scripts. The script should: Open new vertical split with empty buffer (with vnew possibly) In empty buffer launch :.!hg diff Set empty buffer file type as diff :set ft=diff I've written such function: function! HgCiDiff() vnew :.!hg diff set ft=diff endfunction And in .hgrc I've added option: editor = vim "+HgCiDiff()" It kind of works, but I would like that splited window would be in right side (now it opens up in left) and mercurial message would be focused window. Also :wq could be setted as temporary shortcut to :wq<CR>:q! (having an assumption that mercurial message is is focused). Any suggestions to make this a bit more useful and less chunky? UPDATE: I found vim split guide so changing vnew with rightbelow vnew opens up diff on the right side.

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• C++ operator lookup rules / Koenig lookup

  - by John Bartholomew

  While writing a test suite, I needed to provide an implementation of operator<<(std::ostream&... for Boost unit test to use. This worked: namespace theseus { namespace core { std::ostream& operator<<(std::ostream& ss, const PixelRGB& p) { return (ss << "PixelRGB(" << (int)p.r << "," << (int)p.g << "," << (int)p.b << ")"); } }} This didn't: std::ostream& operator<<(std::ostream& ss, const theseus::core::PixelRGB& p) { return (ss << "PixelRGB(" << (int)p.r << "," << (int)p.g << "," << (int)p.b << ")"); } Apparently, the second wasn't included in the candidate matches when g++ tried to resolve the use of the operator. Why (what rule causes this)? The code calling operator<< is deep within the Boost unit test framework, but here's the test code: BOOST_AUTO_TEST_SUITE(core_image) BOOST_AUTO_TEST_CASE(test_output) { using namespace theseus::core; BOOST_TEST_MESSAGE(PixelRGB(5,5,5)); // only compiles with operator<< definition inside theseus::core std::cout << PixelRGB(5,5,5) << "\n"; // works with either definition BOOST_CHECK(true); // prevent no-assertion error } BOOST_AUTO_TEST_SUITE_END() For reference, I'm using g++ 4.4 (though for the moment I'm assuming this behaviour is standards-conformant).

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• How to Create a Simple Dictation Pad in Delphi2009+Vista

  - by XBasic3000

  the code are not so complecated.. private { Private declarations } SpSharedRecoContext1 : TSpSharedRecoContext; fMyGrammar : ISpeechRecoGrammar; procedure SpSharedRecoContext1Recognition(ASender: TObject; StreamNumber: Integer; StreamPosition: OleVariant; RecognitionType: SpeechRecognitionType; const Result: ISpeechRecoResult); procedure SpSharedRecoContext1Hypothesis(ASender: TObject; StreamNumber: Integer; StreamPosition: OleVariant; const Result: ISpeechRecoResult); procedure TForm1.FormCreate(Sender: TObject); begin SpSharedRecoContext1 := TSpSharedRecoContext.Create(self); SpSharedRecoContext1.OnHypothesis := SpSharedRecoContext1Hypothesis; SpSharedRecoContext1.OnRecognition :=SpSharedRecoContext1Recognition; fMyGrammar := SpSharedRecoContext1.CreateGrammar(0); fMyGrammar.DictationSetState(SGDSActive); end; procedure TForm1.SpSharedRecoContext1Recognition(ASender: TObject; StreamNumber: Integer; StreamPosition: OleVariant; RecognitionType: SpeechRecognitionType; const Result: ISpeechRecoResult); begin Memo1.Text := Result.PhraseInfo.GetText(0,-1,true); end; procedure TForm1.SpSharedRecoContext1Hypothesis(ASender: TObject; StreamNumber: Integer; StreamPosition: OleVariant; const Result: ISpeechRecoResult); begin Memo1.Text := Result.PhraseInfo.GetText(0,-1,true); end; My Problem, was the vista-OS voice command will intercept on my program. if i say "START", instead of writing start on memo1 it press the start menu on my desktop. or what ever command like START CANCEL EDIT DELETE SELECT etc. please help..... sorry for my english

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• Can someone tell me what this Java class does? I/O related

  - by anon

  I am relatively new to Java and trying to learn the I/O syntax. Could someone give me a general overview of what this code does? Thanks!! import java.io.*; public class FileReader { private String openFile=""; private String saveFile=""; FileReader(openFile, saveFile) { this.openFile=openFile; this.saveFile=saveFile; } public String process(){ System.out.println(this.openFile); System.out.println(this.saveFile); BufferedReader open=null; FileReader openFR=null; FileWriter save=null; int counter=0; String output=""; if(openFile.equals("")){ return "No open file specifified\n"; } if(this.saveFile.equals("")){ return "No save file specified\n"; } try { openFR = new FileReader(this.openFile); open = new BufferedReader(openFR); } catch (FileNotFoundException e) { return ("Open file no longer exists\n"); } try { save = new FileWriter(saveFile); } catch (IOException e){ return ("Error saving the file\n"); } try{ String temp = open.readLine(); while(temp != null){ temp = open.readLine(); counter++; save.write(output + "\n"); } } catch (IOException e){ e.getStackTrace(); return ("Error reading open file"); } try { save.flush(); } catch (IOException e) { e.printStackTrace(); return ("Error writing save file"); } return "Operation completed successfully"; } }

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• Use PermGen space or roll-my-own intern method?

  - by Adamski

  I am writing a Codec to process messages sent over TCP using a bespoke wire protocol. During the decode process I create a number of Strings, BigDecimals and dates. The client-server access patterns mean that it is common for the client to issue a request and then decode thousands of response messages, which results in a large number of duplicate Strings, BigDecimals, etc. Therefore I have created an InternPool<T> class allowing me to intern each class of object. Internally, the pool uses a WeakHashMap<T, WeakReferemce<T>>. For example: InternPool<BigDecimal> pool = new InternPool<BigDecimal>(); ... // Read BigDecimal from in buffer and then intern. BigDecimal quantity = pool.intern(readBigDecimal(in)); My question: I am using InternPool for BigDecimal but should I consider also using it for String instead of String's intern() method, which I believe uses PermGen space? What is the advantage of using PermGen space?

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• Why is TRest in Tuple<T1... TRest> not constrained?

  - by Anthony Pegram

  In a Tuple, if you have more than 7 items, you can provide an 8th item that is another tuple and define up to 7 items, and then another tuple as the 8th and on and on down the line. However, there is no constraint on the 8th item at compile time. For example, this is legal code for the compiler: var tuple = new Tuple<int, int, int, int, int, int, int, double> (1, 1, 1, 1, 1, 1, 1, 1d); Even though the intellisense documentation says that TRest must be a Tuple. You do not get any error when writing or building the code, it does not manifest until runtime in the form of an ArgumentException. You can roughly implement a Tuple in a few minutes, complete with a Tuple-constrained 8th item. I just wonder why it was left off the current implementation? Is it possibly a forward-compatibility issue where they could add more elements with a hypothetical C# 5? Short version of rough implementation interface IMyTuple { } class MyTuple<T1> : IMyTuple { public T1 Item1 { get; private set; } public MyTuple(T1 item1) { Item1 = item1; } } class MyTuple<T1, T2> : MyTuple<T1> { public T2 Item2 { get; private set; } public MyTuple(T1 item1, T2 item2) : base(item1) { Item2 = item2; } } class MyTuple<T1, T2, TRest> : MyTuple<T1, T2> where TRest : IMyTuple { public TRest Rest { get; private set; } public MyTuple(T1 item1, T2 item2, TRest rest) : base(item1, item2) { Rest = rest; } } ... var mytuple = new MyTuple<int, int, MyTuple<int>>(1, 1, new MyTuple<int>(1)); // legal var mytuple2 = new MyTuple<int, int, int>(1, 2, 3); // illegal

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• Componentizing complex functionality in an MVC web app

  - by NXT

  Hi Everyone, This is question about MVC web-app architecture, and how it can be extended to handle componentizing moderately complex units of functionality. I have an MVC style web-app with a customer facing credit card charge page. I've been asked to allow the admins to enter credit card payments as well, for times when credit cards are taken over the phone. The customer facing credit card charge section of the website is currently it's own controller, with approximately 3 pages and a login. That controller is responsible for: Customer login credential authentication Credit card data collection Calling a library to do the actual charge. reporting the results to the user. I would like to extract the card data collection pages into a component of some kind so that I can easily reuse the code on the admin side of the app. Right now my components are limited to single "view" pages with PHP style embedded Perl code. This is a simple, custom MVC framework written in Perl. Right now, controllers are called directly from the framework to service web requests. My idea is to allow controllers to be called from other controllers, so that I can componentize more complex functionality. For simplicity I think I prefer composition over inheritance, even though it will require writing a bunch of pass-through methods (actions). Being Perl, I could in theory do multiple inheritance. I'm wondering if anyone with experience in other MVC web frameworks can comment on how this sort of thing is usually done. Thank you.

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• C++ socket concurrent server

  - by gregpi

  Hi all; Im writing a concurrent server that's supposed to have a communication channel and a data channel. The client initially connect to the communication channel to authenticate, upon successful authentication, the client is then connected to the data channel to access data. My program is already doing that, and im using threads.My only issue is that if I try to connect another client, I get a "cannot bind : address already in use" error. I have it this way: PART A Client connect to port 4567 (and enter his login info). A thread spawn to handle the client(repeated for each client that connects). In the thread created, I have a function(let's call it FUNC_A) that checks the client's login info(dont worry about how the check is done), if successful, the thread starts the data server(listening on 8976) then sends an OK to the client, once received the client attempts to connect to the data server. PART B Once a client connect to the data server, from inside FUNC_A the client is accepted and another thread is spawn to handle the client's connection to the data server.(hopefully everything is clear). Now, all that is working fine. However, if I try to connect with second client when it gets to PART B I get a "cannot bind error: address already in use". I've tried so many different ways, I've even tried spawning a thread to start the data server and accept the client and then start another thread to handle that connection. still no luck. Please give me a suggestion as to what I'm doing wrong, how do I go about doing this or what's the best way to implement it. Thank you

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• Widget host app with custom view - onClick is not triggered in the app widget.

  - by Dennis K

  I'm writing an app that will host widgets. The app has custom view (which probably is the source of issue). I obtain AppWidgetHostView like this private AppWidgetHostView widget; ... AppWidgetProviderInfo appWidgetInfo = mAppWidgetManager.getAppWidgetInfo(appWidgetId); widget = mAppWidgetHost.createView(this, appWidgetId, appWidgetInfo); widget.setAppWidget(appWidgetId, appWidgetInfo); mView.addWidget(widget, appWidgetInfo); mView.addWidget() basically just remembers this AppWidgetHostView instance and then draws it directly onto canvas. Visually everything is fine - I can see the actual widget. But the issue is with reacting on UI events. Please advise what needs to be done in the parent view in order to correctly trigger handlers in the widgets like onClick(). Notes: I used standard widgets which normally react on click events. None worked. I also created my own test widget with listener (via views.setOnClickPendingIntent(R.id.appwidget_text, pending);) and onClick() is successfully triggered if the widget is added on Homescreen, but doesn't work in my app. mView correctly detects click event and I tried to call widget.performClick() there, which returns false meaning onClickListener is not registered in the widget. But according to source mAppWidgetHost.createView() would call updateAppWidget which would register its onClick listener.. Please advise where to look at. Thanks

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• Question about the evolution of interaction paradigm between web server program and content provider program?

  - by smwikipedia

  Hi experts, In my opinion, web server is responsible to deliver content to client. If it is static content like pictures and static html document, web server just deliver them as bitstream directly. If it is some dynamic content that is generated during processing client's request, the web server will not generate the conetnt itself but call some external proram to genearte the content. AFAIK, this kind of dynamice content generation technologies include the following: CGI ISAPI ... And from here, I noticed that: ...In IIS 7, modules replace ISAPI filters... Is there any others? Could anyone help me complete the above list and elabrate on or show some links to their evolution? I think it would be very helpful to understand application such as IIS, TomCat, and Apache. I once wrote a small CGI program, and though it serves as a content generator, it is still nothing but a normal standalone program. I call it normal because the CGI program has a main() entry point. But with the recenetly technology like ASP.NET, I am not writing complete program, but only some class library. Why does such radical change happens? Many thanks.

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• How to establish a socket connection from iPhone to a Apache server and communicate via PHP?

  - by candoyo

  Hi, I am working on an iPhone game which is depended on a LAMP server. I want to create a "event" based system where the apache server sends an event to the iphone. For this, I am thinking of using "CFStreamCreatePairWithSocketToHost" to connect to port 80 of the apache server. I am able to successfully connect to the server and open a read and write stream via the iPhone, but I am not sure how to send data to the iphone using PHP running from the LAMP server to the iPhone. I think I can use fsockopen in php to open a socket connection and write data to that socket. I tired running this code $fp = fsockopen("tcp://localhost", 80, $errno, $errstr); if (!$fp) { echo "ERROR: $errno - $errstr<br />\n"; } else { echo"writing to socket "; fwrite($fp, "wwqeqweqw eqwe qwe \n"); //echo fread($fp, 26); fclose($fp); echo "done"; } But, I dont see anything being read on the iphone.. Any idea what's going on, or how to accomplish this? Thanks!

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• Fake serial communication under Linux

  - by kigurai

  I have an application where I want to simulate the connection between a device and a "modem". The device will be connected to a serial port and will talk to the software modem through that. For testing purposes I want to be able to use a mock software device to test send and receive data. Example Python code device = Device() modem = Modem() device.connect(modem) device.write("Hello") modem_reply = device.read() Now, in my final app I will just pass /dev/ttyS1 or COM1 or whatever for the application to use. But how can I do this in software? I am running Linux and application is written in Python. I have tried making a FIFO (mkfifo ~/my_fifo) and that does work, but then I'll need one FIFO for writing and one for reading. What I want is to open ~/my_fake_serial_port and read and write to that. I have also lpayed with the ptymodule, but can't get that to work either. I can get a master and slave file descriptor from pty.openpty() but trying to read or write to them only causes IOError Bad File Descriptor error message.

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• How do I cast a void pointer to a struct in C?

  - by Rowhawn

  In a project I'm writing code for, I have a void pointer, "implementation", which is a member of a "Hash_map" struct, and points to an "Array_hash_map" struct. The concepts behind this project are not very realistic, but bear with me. The specifications of the project ask that I cast the void pointer "implementation" to an "Array_hash_map" before I can use it in any functions. My question, specifically is, what do I do in the functions to cast the void pointers to the desired struct? Is there one statement at the top of each function that casts them or do I make the cast every time I use "implementation"? Here are the typedefs the structs of a Hash_map and Array_hash_map as well as a couple functions making use of them. typedef struct { Key_compare_fn key_compare_fn; Key_delete_fn key_delete_fn; Data_compare_fn data_compare_fn; Data_delete_fn data_delete_fn; void *implementation; } Hash_map; typedef struct Array_hash_map{ struct Unit *array; int size; int capacity; } Array_hash_map; typedef struct Unit{ Key key; Data data; } Unit; functions: /* Sets the value parameter to the value associated with the key parameter in the Hash_map. */ int get(Hash_map *map, Key key, Data *value){ int i; if (map == NULL || value == NULL) return 0; for (i = 0; i < map->implementation->size; i++){ if (map->key_compare_fn(map->implementation->array[i].key, key) == 0){ *value = map->implementation->array[i].data; return 1; } } return 0; } /* Returns the number of values that can be stored in the Hash_map, since it is represented by an array. */ int current_capacity(Hash_map map){ return map.implementation->capacity; }

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• Semantically correct XHTML markup

  - by Dori

  Hello all. Just trying to get the hang of using the semantically correct XHTML markup. Just writing the code for a small navigation item. Where each button has effectivly a title and a descrption. I thought a definition list would therefore be great so i wrote the following <dl> <dt>Import images</dt> <dd>Read in new image names to database</dd> <dt>Exhibition Management</dt> <dd>Create / Delete an exhibition </dd> <dt>Image Management</dt> <dd>Edit name, medium and exhibition data </dd> </dl> But...I want the above to be 3 buttons, each button containing the dt and dd text. How can i do this with the correct code? Normally i would make each button a div and use that for the visual button behaviour (onHover and current page selection stuff). Any advice please Thanks

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• Namespace constraint with generic class decleration

  - by SomeGuy

  Good afternoon people, I would like to know if (and if so how) it is possible to define a namespace as a constraint parameter in a generic class declaration. What I have is this: namespace MyProject.Models.Entities <-- Contains my classes to be persisted in db namespace MyProject.Tests.BaseTest <-- Obvious i think Now the decleration of my 'BaseTest' class looks like so; public class BaseTest<T> This BaseTest does little more (at the time of writing) than remove all entities that were added to the database during testing. So typically I will have a test class declared as: public class MyEntityRepositoryTest : BaseTest<MyEntity> What i would LIKE to do is something similar to the following: public class BaseTest<T> where T : <is of the MyProject.Models.Entities namespace> Now i am aware that it would be entirely possible to simply declare a 'BaseEntity' class from which all entities created within the MyProject.Models.Entities namespace will inherit from; public class BaseTest<T> where T : MyBaseEntity but...I dont actually need to, or want to. Plus I am using an ORM and mapping entities with inheritance, although possible, adds a layer of complexity that is not required. So, is it possible to constrain a generic class parameter to a namespace and not a specific type ? Thank you for your time.

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• Objective C code to handle large amount of data processing in iPhone

  - by user167662

  I had the following code that takes in 14 mb or more of image data encoded in base4 string and converts them to jpeg before writing to a file in iphone. It crashes my program giving the following error : Program received signal: “0”. warning: check_safe_call: could not restore current frame I tweak my program and it can process a few more images before the error appear again. My coding is as follows: // parameters is an array where the fourth element contains a list of images in base64 >encoded string NSMutableArray *imageStrList = (NSMutableArray*) [parameters objectAtIndex:5]; while (imageStrList.count != 0) { NSString *imgString = [imageStrList objectAtIndex:0]; // Create a file name using my own Utility class NSString *fileName = [Utility generateFileNName]; NSData *restoredImg = [NSData decodeWebSafeBase64ForString:imgString]; UIImage *img = [UIImage imageWithData: restoredImg]; NSData *imgJPEG = UIImageJPEGRepresentation(img, 0.4f); [imgJPEG writeToFile:fileName atomically:YES]; [imageStrList removeObjectAtIndex:0]; } I tried playing around with UIImageJPEGRepresentation and found out that the lower the value, the more image it can processed but this should not be the way. I am wondering if there is anyway to free up memory of the imageStrList immediately after processing each image so that it can be used by the next one in the line.

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• Write raw struct contents (bytes) to a file in C. Confused about actual size written

  - by d11wtq

  Basic question, but I expected this struct to occupy 13 bytes of space (1 for the char, 12 for the 3 unsigned ints). Instead, sizeof(ESPR_REL_HEADER) gives me 16 bytes. typedef struct { unsigned char version; unsigned int root_node_num; unsigned int node_size; unsigned int node_count; } ESPR_REL_HEADER; What I'm trying to do is initialize this struct with some values and write the data it contains (the raw bytes) to the start of a file, so that when I open this file I later I can reconstruct this struct and gain some meta data about what the rest of the file contains. I'm initializing the struct and writing it to the file like this: int esprime_write_btree_header(FILE * fp, unsigned int node_size) { ESPR_REL_HEADER header = { .version = 1, .root_node_num = 0, .node_size = node_size, .node_count = 1 }; return fwrite(&header, sizeof(ESPR_REL_HEADER), 1, fp); } Where node_size is currently 4 while I experiment. The file contains the following data after I write the struct to it: -bash$ hexdump test.dat 0000000 01 bf f9 8b 00 00 00 00 04 00 00 00 01 00 00 00 0000010 I expect it to actually contain: -bash$ hexdump test.dat 0000000 01 00 00 00 00 04 00 00 00 01 00 00 00 0000010 Excuse the newbiness. I am trying to learn :) How do I efficiently write just the data components of my struct to a file?

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