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  • Avoid using InetAddress - Getting a raw IP address in network byte order

    - by Mylo
    Hey, I am trying to use the MaxMind GeoLite Country database on the Google App Engine. However, I am having difficulty getting the Java API to work as it relies on the InetAddress class which is not available to use on the App Engine. However, I am not sure if there is a simple workaround as it appears it only uses the InetAddress class to determine the IP of a given hostname. In my case, the hostname is always an IP anyway. What I need is a way to convert an IP address represented as a String into a byte array of network byte order (which the addr.getAddress() method of the InetAddress class provides). This is the code the current API uses, I need to find a way of removing all references to InetAddress whilst ensuring it still works! Thanks for your time. /** * Returns the country the IP address is in. * * @param ipAddress String version of an IP address, i.e. "127.0.0.1" * @return the country the IP address is from. */ public Country getCountry(String ipAddress) { InetAddress addr; try { addr = InetAddress.getByName(ipAddress); } catch (UnknownHostException e) { return UNKNOWN_COUNTRY; } return getCountry(bytesToLong(addr.getAddress())); }

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  • How can manage a FIFO-queue in an database with SQL?

    - by Jonas
    I have two tables in my database, one for In and one for Out. They have two columns, Quantity and Price. How can I write a SQL-query that selects the correct price? In example: If I have 3 items in for 75 and then 3 items in for 80. Then I have two out for 75, and the third out should be for 75 (X) and the fourth out should be for 80 (Y). How can I write the price query for X and Y? They should use the price from the third and forth row. In example, is there any way to SELECT the third row in the In-table? I can not use auto_increment as identifier for i.e. "third" row, because the tables will contain post for other items too. The rows will not be deleted, they will be saved for accountability reasons. SELECT Price FROM In WHERE ...? NEW database design: +----+ | In | +----+------+-------+ | Supply_ID | Price | +-----------+-------+ | 1 | 75 | | 1 | 75 | | 1 | 75 | | 2 | 80 | | 2 | 80 | +-----------+-------+ +-----+ | Out | +-----+-------+-------+ | Delivery_ID | Price | +-------------+-------+ | 1 | 75 | | 1 | 75 | | 2 | X | <- ? | 3 | Y | <- ? +-------------+-------+ OLD database design: +----+ | In | +----+------+----------+-------+ | Supply_ID | Quantity | Price | +-----------+----------+-------+ | 1 | 3 | 75 | | 2 | 3 | 80 | +-----------+----------+-------+ +-----+ | Out | +-----+-------+----------+-------+ | Delivery_ID | Quantity | Price | +-------------+----------+-------+ | 1 | 2 | 75 | | 2 | 1 | X | <- ? | 3 | 1 | Y | <- ? +-------------+----------+-------+

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  • Code Analysis Warning CA1004 with generic method

    - by Vaccano
    I have the following generic method: // Load an object from the disk public static T DeserializeObject<T>(String filename) where T : class { XmlSerializer xmlSerializer = new XmlSerializer(typeof(T)); try { TextReader textReader = new StreamReader(filename); var result = (T)xmlSerializer.Deserialize(textReader); textReader.Close(); return result; } catch (FileNotFoundException) { } return null; } When I compile I get the following warning: CA1004 : Microsoft.Design : Consider a design where 'MiscHelpers.DeserializeObject(string)' doesn't require explicit type parameter 'T' in any call to it. I have considered this and I don't know a way to do what it requests with out limiting the types that can be deserialized. I freely admit that I might be missing an easy way to fix this. But if I am not, then is my only recourse to suppress this warning? I have a clean project with no warnings or messages. I would like to keep it that way. I guess I am asking "why this is a warning?" At best this seems like it should be a message. And even that seems a bit much. Either it can or it can't be fixed. If it can't then you are just stuck with the warning with no recourse but suppressing it. Am I wrong?

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  • My Rails session is getting reset when I have concurrent requests

    - by alex_c
    I think I might be misunderstanding something about Rails sessions, so please bear with me, I might not be phrasing my question the best way. I'm working on an iPhone app with a Ruby on Rails backend. I have a web view which by default goes to the index action of one controller (and uses sessions), and in the background a bunch of API calls going to a different controller (and which don't need to use sessions). The problem is, the sessions set by my web view seem to be overwitten by the API calls. My staging server is pretty slow, so there's lots of time for the requests to overlap each other - what I see in the logs is basically this: Request A (first controller) starts. Session is empty. Request B (second controller) starts. Session is empty. Request A finishes. Request A has done authentication, and stored the user ID in the session. Session contains user ID. Request B finishes. Session is empty. Request C starts. Session is empty - not what I want. Now, the strange thing is that request B should NOT be writing anything to the session. I do have before and after filters which READ from the session - things like: user = User.find_by_id(session[:id]) or logger.debug session.inspect and if I remove all of those, then everything works as expected - session contents get set by request A, and they're still there when request C starts. So. I think I'm missing something about how sessions work. Why would reading from the session overwrite it? Should I be accessing it some other way? Am I completely on the wrong track and the problem is elsewhere? Thank you for any insights!

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  • What is better: Developing a Web project in MVC or N -Tier Architecture?

    - by Starx
    I have asked a similar question before and got an convincing answer as well? http://stackoverflow.com/questions/2843311/what-is-difference-of-developing-a-website-in-mvc-and-3-tier-or-n-tier-architectu Due to the conclusion of this question I started developing projects in N-tier Architecture. Just about an hour ago, I asked another question, about what is the best design pattern to create interface? There the most voted answer is suggesting me to use MVC architecture. http://stackoverflow.com/questions/2930300/what-is-the-best-desing-pattern-to-design-the-interface-of-an-webpage Now I am confused, First post suggested me that both are similar, just a difference that in N-tier, the tier are physically and logically separated and one layer has access to the one above and below it but not all the layers. I think ASP.net used 3 Tier architecture while developing applications or Web applications. Where as frameworks like Zend, Symphony they use MVC. I just want to stick to a pattern that is best suitable for WebProject Development? May be this is a very silly confusion? But if someone could clear this confusion, that would be very greatful?

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  • Android: How to periodically check current location without draining the battery

    - by uyahalom
    I have a background service which works periodically by timer.scheduleAtFixedRate. It wakes up every amount of time (let's say 60 seconds for example) and checks for the location. The location is checked by locManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 60000, 5, listener); and the actual location is collected from the listener's onLocationChanged. Now, when the phone is outside and GPS reception is good, this works fine. But, if the phone is inside, the GPS is almost always active - looking for a signal, and the battery is drained rapidly. I created another thread using a Handler and a Runnable in order to conrol the GPS active time accurately: I used locManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, listener); and locManager.removeUpdates(listener); so I can open and close the GPS as I want. In this case, I can open the GPS for the exact amount of time, but found out that it doesn't lock in an area with good reception even after 10 seconds. So here I'm draining the battery again... I'm using API level 7, hence I cannot use locationManager.requestSingleUpdate. I have two questions: Is there any way to optimize this process? Will upgrading to API level 9 (and use locationManager.requestSingleUpdate) improve the process significantly? I mean, does it worth upgrading?

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  • Using in the same time Boost in release and debug mode

    - by Oodini
    Hello, The title is just for teasing. :-) I know it isn't possible, but here is my problem. My app (a DLL, actually) uses Boost. It also uses an external API, which also uses Boost. The external API is of course provided in a release binary, anlong the needed release Boost binaries. When I compile/link my DLL in release mode, I have no problem. I precise I link my app to Boost in a dynamic way (BOOST_ALL_DYN_LINK). In debug mode, I can't load my DLL. I am not sure it is because of Boost, but I suspect Windows doesn't like working with two Boost (the release one called by the external lib, and the debug one called by my code). Will it work better if I link my code statically with the release Boost ? I don't think it is related to CRT, because I have nothing in the Events Viewer. I use Visual Studio 2005 SP1. Thanks.

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  • How to make dialog to look like ICS theme

    - by Naruto
    from service i'm creating a dialog via a dummy activity. Here i'm able to see black background, overall the theme of dialog looks like Android V 2.2. My application minimum API level is 8, if i use holo theme it says i need min api level as 14. Here is the code i used to create dialog. How to get ICS theme dialog. public class PreviewDialog extends Activity{ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Show the popup dialog showDialog(0); } @Override protected Dialog onCreateDialog(int id) { super.onCreateDialog(id); // Build the dialog AlertDialog.Builder alert = new AlertDialog.Builder(this); alert.setTitle("ALARM REMINDER"); alert.setMessage("Its time for the alarm "); alert.setCancelable(false); alert.setPositiveButton("Dismiss", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int whichButton) { GoogleTaskPreviewDialog.this.finish(); } }); // Create and return the dialog AlertDialog dlg = alert.create(); return dlg; } } MY manifest file entry <activity android:name="PreviewDialog" android:theme="@android:style/Theme.Translucent.NoTitleBar"></activity>

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  • "end()" iterator for back inserters?

    - by Thanatos
    For iterators such as those returned from std::back_inserter(), is there something that can be used as an "end" iterator? This seems a little nonsensical at first, but I have an API which is: template<typename InputIterator, typename OutputIterator> void foo( InputIterator input_begin, InputIterator input_end, OutputIterator output_begin, OutputIterator output_end ); foo performs some operation on the input sequence, generating an output sequence. (Who's length is known to foo but may or may not be equal to the input sequence's length.) The taking of the output_end parameter is the odd part: std::copy doesn't do this, for example, and assumes you're not going to pass it garbage. foo does it to provide range checking: if you pass a range too small, it throws an exception, in the name of defensive programming. (Instead of potentially overwriting random bits in memory.) Now, say I want to pass foo a back inserter, specifically one from a std::vector which has no limit outside of memory constraints. I still need a "end" iterator - in this case, something that will never compare equal. (Or, if I had a std::vector but with a restriction on length, perhaps it might sometimes compare equal?) How do I go about doing this? I do have the ability to change foo's API - is it better to not check the range, and instead provide an alternate means to get the required output range? (Which would be needed anyways for raw arrays, but not required for back inserters into a vector.) This would seem less robust, but I'm struggling to make the "robust" (above) work.

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  • Problem with making a simple JS XmlHttpRequest call

    - by recipriversexclusion
    I have to create a very simple client that makes GET and POST calls to our server and parses the returned XML. I am writing this in JavaScript, problem is I don't know how to program in JS (started to look into this just this morning)! As n initial test, I am trying to ping to the Twitter API, here's the function that gets called when user enters the URL http://api.twitter.com/1/users/lookup.xml and hits the submit button: function doRequest() { var req_url, req_type, body; req_url = document.getElementById('server_url').value; req_type = document.getElementById('request_type').value; alert("Connecting to url: " + req_url + " with HTTP method: " + req_type); req = new XMLHttpRequest(); req.open(req_type, req_url, false, "username", "passwd");// synchronous conn req.onreadystatechange=function() { if (req.readyState == 4) { alert(req.status); } } req.send(null); } When I run this on FF, I get a Access to restricted URI denied" code: "1012 error on Firebug. Stuff I googled suggested that this was a FF-specific problem so I switched to Chrome. Over there, the second alert comes up, but displays 0 as HTTP status code, which I found weird. Can anyone spot what the problem is? People say this stuff is easier to use with JQuery but learning that on top of JS syntax is a bit too much now.

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  • callback on a variable which is inside a .each() loop

    - by Stoic
    I have this function, which is doing an asynchronous call to FB.api method. Now, i am looping over some data and capturing result of the above method call successfully. However, I am using a .each loop and I really can not figure out how to place my callback in this method, so that the outer method is only executed once. Here are the functions I am using: ask_for_perms($(this).val(),function(result) { $('#some-div').html('<a onclick = "get_perms(result);" >get perms</a>'); }); function ask_for_perms(perms_requested,cb) { var request = []; $.each(perms_requested,function(i,permission) { FB.api({ method: 'users.hasAppPermission', ext_perm: permission }, function(response) { if (response == 0) request.push(permission); request.join(','); cb(request); // cb is called many times here. }); }); } I am trying to return the request string from ask_for_perms function. Can anyone suggest me on where to place a proper callback to ask_for_perms. Right now, however, it works for me, but the callback is being called many times since it is inside a for loop. referencing: returning a variable from the callback of a function

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  • ctypes DLL with optional dependencies

    - by pisswillis
    Disclaimer: I'm new to windows programming so some of my assumptions may be wrong. Please correct me if so. I am developing a python wrapper for a C API using ctypes. The API ships with both 64 and 32 DLLs/LIBs. I can succesfully load the DLL using ctypes.WinDLL('TheLibName') and call functions etc etc. However some functions were not doing what they should. Upon further investigation it appears that the 32bit DLL is being used, which is what is causing the unexpected behaviour. I have tried using ctypes.WinDLL('TheLibName64') but the module is not found. I have tried registering the DLL with regsrv32, but it reports there is no entry point (it also reports no entry point when I try and register TheLibName, which is found by WinDLL(). The DLL came with a sample project in Visual Studio (I have 0 experience with VS so again please correct me here) which builds both 32 and 64 bit versions of the sample project. In the .vcsproj file the configurations for the 64 bit version include: AdditionalDependencies="TheLibName64.lib" in the VCLinkerTool section. In windows/system32 there are both TheLibName.dll/.lib, and TheLibName64.dll/.lib. So it seems to me that my problem is now to make the python ctypes DLL loader load these optional dependencies when the DLL is loaded. However I can't find any information on this (perhaps because, as a doze noob, I do not know the correct terminology) in the ctypes documentation. Is there a way to do this in ctypes? Am I going about this in completely the wrong way? Any help or general information about optional DLL dependencies and how they are loaded in windows would be much appreciated. Thanks

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  • How do I set up the python/c library correctly?

    - by Bartvbl
    I have been trying to get the python/c library to like my mingW compiler. The python online doncumentation; http://docs.python.org/c-api/intro.html#include-files only mentions that I need to import the python.h file. I grabbed it from the installation directory (as is required on the windows platform), and tested it by compiling the script: #include "Python.h". This compiled fine. Next, I tried out the snippet of code shown a bit lower on the python/c API page: PyObject *t; t = PyTuple_New(3); PyTuple_SetItem(t, 0, PyInt_FromLong(1L)); PyTuple_SetItem(t, 1, PyInt_FromLong(2L)); PyTuple_SetItem(t, 2, PyString_FromString("three")); For some reason, the compiler would compile the code if I'd remove the last 4 lines (so that only the pyObject variable definition would be left), yet calling the actual constructor of the tuple returned errors. I am probably missing something completely obvious here, given I am very new to C, but does anyone know what it is?

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  • Google Maps + PODSCMS

    - by Sharath
    Hi, I have a column called 'location' in a POD which I have created. I was looking to write a input helper where I display a Google Map and the user clicks on a location, and I capture that into this column. This is what I am trying to do <div class="form pick <?php echo $location; ?>"> <script src="http://maps.google.com/maps?file=api&v=1&key=<key_here>" type="text/javascript"></script> <div id="map" style="width:500; height:500"> <script type="text/javascript"> map=new GMap(document.getElementById("map")); map.centerAndZoom(new GPoint(77.595062,13.043359),6); map.setUIToDefault(); </script> </div> </div> But I am getting a number of errors from google maps API. Any idea how i can get this helper in there?

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  • Method not found: 'Void Google.Apis.Util.Store.FileDataStore..ctor(System.String)'

    - by user3732193
    I've been stuck at this for days now. I copied the exact codes from google api samples to upload files to Google Drive. Here is the code UserCredential credential = GoogleWebAuthorizationBroker.AuthorizeAsync( new ClientSecrets { ClientId = ClientId, ClientSecret = ClientSecret, }, new[] { DriveService.Scope.Drive, DriveService.Scope.DriveFile }, "user", CancellationToken.None, new FileDataStore("MyStore")).Result; But it would throw an exception at runtime: Method not found: 'Void Google.Apis.Util.Store.FileDataStore..ctor(System.String)'. I already added the necessary Google Api dlls. Or if anyone could suggest a better code for uploading files to Google Drive in a website which implements Server-Side Authorization. Any help would be greatly appreciated. UPDATE: I changed my code to this var token = new TokenResponse { RefreshToken = "1/6hnki1x0xOMU4tr5YXNsLgutzbTcRK1M-QOTEuRVxL4" }; var credentials = new UserCredential(new GoogleAuthorizationCodeFlow(new GoogleAuthorizationCodeFlow.Initializer { ClientSecrets = new ClientSecrets { ClientId = ClientId, ClientSecret = ClientSecret }, Scopes = new[] { DriveService.Scope.Drive, DriveService.Scope.DriveFile } }), "user", token); But it also throws an exception: Method not found: 'Void Google.Apis.Auth.OAuth2.Flows.GoogleAuthorizationCodeFlow..ctor(Initializer). Is the problem with the dlls?

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  • C++ private inheritance and static members/types

    - by WearyMonkey
    I am trying to stop a class from being able to convert its 'this' pointer into a pointer of one of its interfaces. I do this by using private inheritance via a middle proxy class. The problem is that I find private inheritance makes all public static members and types of the base class inaccessible to all classes under the inheriting class in the hierarchy. class Base { public: enum Enum { value }; }; class Middle : private Base { }; class Child : public Middle { public: void Method() { Base::Enum e = Base::value; // doesn't compile BAD! Base* base = this; // doesn't compile GOOD! } }; I've tried this in both VS2008 (the required version) and VS2010, neither work. Can anyone think of a workaround? Or a different approach to stopping the conversion? Also I am curios of the behavior, is it just a side effect of the compiler implementation, or is it by design? If by design, then why? I always thought of private inheritance to mean that nobody knows Middle inherits from Base. However, the exhibited behavior implies private inheritance means a lot more than that, in-fact Child has less access to Base than any namespace not in the class hierarchy!

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  • Problem with HttpService POST

    - by Lost_in_code
    I'm trying to send some data to PHP using HTTPService POST but for some reason it's not working. The same example works with GET but not with POST: private function start():void{ var param:Object = {}; param.date = "2010-10-10"; userRequest.send(param); userRequest.addEventListener(ResultEvent.RESULT, result); userRequest.addEventListener(FaultEvent.FAULT, fault); } private function fault(e:FaultEvent):void{ trace(e.message); } private function result(e:ResultEvent):void{ trace(e.result); } <mx:HTTPService id="userRequest" url="http://localhost:8888/api" useProxy="false" method="POST"/> And here's the PHP code: $d = $_POST['date']; echo $d; if($d == ""){ trace("Date not found!"); die(); } This is the error I'm getting: "Error #2032: Stream Error. URL: http://localhost:8888/api" But when I change the method in HTTPService to GET and in PHP I get the result as expected - PHP sends back the date: 2010-10-10 What am I doing wrong?

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  • Getting visitors country from their IP

    - by Ali Abdulkarim Salem
    i want to get visitors country via their IP.. right now I'm using this ( http://api.hostip.info/country.php?ip=...... ) here's my code <?php if (isset($_SERVER['HTTP_CLIENT_IP'])) { $real_ip_adress = $_SERVER['HTTP_CLIENT_IP']; } if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) { $real_ip_adress = $_SERVER['HTTP_X_FORWARDED_FOR']; } else { $real_ip_adress = $_SERVER['REMOTE_ADDR']; } $cip = $real_ip_adress; $iptolocation = 'http://api.hostip.info/country.php?ip=' . $cip; $creatorlocation = file_get_contents($iptolocation); ?> Well, it's working properly, but the thing is, this returns the country code like US or CA., and not the whole country name like United States or Canada So, is there any good alternative to hostip.info offers this? I know that I can just write some code that will eventually turn this two letters to whole country name, but I'm just too lazy to write a code that contains all countries... P.S: For some reason I don't want to use any ready made CSV file or any code that will grab this information for me, something like ip2country ready made code and CSV.

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  • No results are returned when using Flickr JSON request

    - by Martijn1981
    I'm still fairly new to AJAX and I'm experimenting with Twitter and Flickr. Twitter is working fine so far, but I've run into some issues with the Flickr API. I'm getting no results back. The URL seems to be working fine and I'm pointing to the right object containing the array ('items'). Can anybody tell me what I'm doing wrong please? Thanks! $('#show_pictures').click(function(e){ e.preventDefault(); $.ajax({ url: 'http://api.flickr.com/services/feeds/photos_public.gne?format=json&jsoncallback=?&tags=home', dataType: 'jsonp', success: function(data) { $.each(data.items, function(i, item){ $('<div></div>') .hide() .append('<h1>'+item.title+'</h1>') .append('<img src="'+item.media.m+'" >') .append('<p>'+item.description+'</p>') .appendTo('#results') .fadeIn(); }) }, error: function(data) { alert('Something went wrong!'); } }); });

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  • Array Indexing Properties of A Class

    - by Chris
    I have a class that has several properties: class Person { string Name; int Age; DateTime BirthDate; } Then I have a sort of wrapper class with a List<Person>. Within this wrapper class I want to be able to do something like Wrapper["Name"] that returns a new List<string> using .Select(x=>x.Name). How do I create a wrapper class around an IEnumerable that supports mapping a string to the Property name? Something like the pseudo code below, but obviously it doesn't work. I'm 99.9% sure the solution will have to use Reflection and thats fine. class Wrapper { List<Person> PersonList; List<dynamic> this[string Column] { return PersonList.Select(x => x.[Column]).ToList(); } } This may not seem like a good design, but its a fix to eventually enable the correct design from .NET 2.0 days. As I have it right now, the data is stored in Columns, so there is actually a List of Lists within my class right now. Using the above example there would be three ILists (with a string Title) Name, Age, and Birthdate. Everything is currently predicated on addressing the columns by their "string" name. I'm trying to convert the data structure to row based with an IEnumberable interface to allow Linq eventually while still maintaining the functionality of my current code. Is converting the code to a Row based IEnumberable a good idea?

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  • Why is there so much XML in Java these days?

    - by BD at Rivenhill
    This is really more of a philosophy/design issue. I did some work in Java back in the middle 90's and again in the early 2000's and now I'm coming back to it after spending a lot of time in C/C++ and it seems like there was an explosion of XML dependency while I was gone. Major build system tools like ant and maven depend on XML for their configuration, but I'm actually more concerned with all the frameworks, such as Spring, Hibernate, etc. My experience is that powerful supporting libraries like these are where a developer can really get leverage for building programs with lots of features without writing a lot of code, but it really seems like I'm getting one language for the price of two here. I write a bunch of Java classes, but then I also write a bunch of XML files to glue them together. The things that get done in the XML are things that I can see reasonable ways of doing in straight code without the middleman, and they don't really seem to be treated exactly like configuration files: they change rarely and they end up getting committed to source code control like the Java code itself, but they are distributed with the resulting application and need to be unpacked and installed in the classpath in order to get the application to work. I'm working with server applications that are not web-based, so maybe the domain is a bit different from what most people are doing, but I just can't help feeling that I must be doing something wrong here. Can someone point me to a good source of information for why these design choices were made and what problems they are meant to solve so that I can analyze my own experiences in this context?

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  • Help me sort programing languages a bit

    - by b-gen-jack-o-neill
    Hi, so I asked here few days ago about C# and its principles. Now, if I may, I have some additional general questions about some languages, becouse for novice like me, it seems a bit confusing. To be exact I want to ask more about language functions capabilities than syntax and so. To be honest, its just these special functions that bothers me and make me so confused. For exmaple, C has its printf(), Pascal has writeln() and so. I know in basic the output in assembler of these funtions would be similiar, every language has more or less its special functions. For console output, for file manipulation, etc. But all these functions are de-facto part of its OS API, so why is for example in C distinguished between C standard library functions and (on Windows) WinAPI functions when even printf() has to use some Windows feature, call some of its function to actually show desired text on console window, becouse the actuall "showing" is done by OS. Where is the line between language functions and system API? Now languages I dont quite understand - Python, Ruby and similiar. To be more specific, I know they are similiar to java and C# in term they are compiled into bytecode. But, I do not unerstand what are its capabilities in term of building GUI applications. I saw tutorial for using Ruby to program GUI applications on Linux and Windows. But isn´t that just some kind of upgrade? I mean fram other tutorials It seemed like these languages was first intended for small scripts than building big applications. I hope you understand why I am confused. If you do, please help me sort it out a bit, I have no one to ask.

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  • How can I prevent infinite recursion when using events to bind UI elements to fields?

    - by Billy ONeal
    The following seems to be a relatively common pattern (to me, not to the community at large) to bind a string variable to the contents of a TextBox. class MyBackEndClass { public event EventHandler DataChanged; string _Data; public string Data { get { return _Data; } set { _Data = value; //Fire the DataChanged event } } } class SomeForm : // Form stuff { MyBackEndClass mbe; TextBox someTextBox; SomeForm() { someTextBox.TextChanged += HandleTextBox(); mbe.DataChanged += HandleData(); } void HandleTextBox(Object sender, EventArgs e) { mbe.Data = ((TextBox)sender).Text; } void HandleData(Object sender, EventArgs e) { someTextBox.Text = ((MyBackEndClass) sender).Data; } } The problem is that changing the TextBox fires the changes the data value in the backend, which causes the textbox to change, etc. That runs forever. Is there a better design pattern (other than resorting to a nasty boolean flag) that handles this case correctly? EDIT: To be clear, in the real design the backend class is used to synchronize changes between multiple forms. Therefore I can't just use the SomeTextBox.Text property directly. Billy3

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  • Is it OK to set state within Event Raising methods?

    - by Greg
    I ran across this pattern in the code of a library I'm using. It sets state within the event raising method, but only if the event is not null. protected virtual void OnMyEvent(EventArgs e) { if(MyEvent != null) { State = "Executing"; // Only sets state if MyEvent != null. MyEvent(this,e); } } Which means that the state is not set when overriding the method: protected override void OnMyEvent(EventArgs e) { base.OnMyEvent(e); Debug.Assert( State == "Executing" ); // This fails } but is only set when handling the event: foo.MyEvent += (o, args) => Debug.Assert(State == "Executing"); // This passes Setting state within the if(MyEvent != null) seems like bad form, but I've checked the Event Design Guidelines and it doesn't mention this. Do you think this code is incorrect? If so, why? (Reference to design guidelines would be helpful). Edit for Context: It's a Control, I'm trying to create subclass of it, and the state that it's setting is calling EnsureChildControls() conditionally based upon there being an event handler. I can call EnsureChildControls() myself, but I consider that something of a hack.

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  • Anything wrong with my cURL code (http status of 0)?

    - by Ilya
    Consistently getting a status of 0 even though if I copy and paste the url sent into my browser, I get a json object right back <?php $mainUrl = "https://api.xxxx.com/?"; $co = "xxxxx"; $pa = "xxxx"; $par = "xxxx"; $part= "xxxx"; $partn = "xxxx"; $us= "xxx"; $fields_string; $fields = array( 'co'=>urlencode($co), 'pa'=>urlencode($pa), 'par'=>urlencode($par), 'part'=>urlencode($part), 'partn'=>urlencode($partn), 'us'=>urlencode($us) ); foreach($fields as $key=>$value) { $fields_string .= $key . '=' . $value . '&' ;} $fields_string = rtrim($fields_string, "&"); $fields_string = "?" . $fields_string; $url = "https://api.xxxxx.com/" . $fields_string; $request = $url; $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, $url); curl_setopt($ch, CURLOPT_RETURNTRANSFER,1); curl_setopt($ch, CURLOPT_TIMEOUT,'3'); $content = trim(curl_exec($ch)); $http_status = curl_getinfo($ch, CURLINFO_HTTP_CODE); curl_close($ch); print $url; print $http_status; print $content; ?>

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