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• Sending custom PyQt signals?

  - by Enfors

  I'm practicing PyQt and (Q)threads by making a simple Twitter client. I have two Qthreads. Main/GUI thread. Twitter fetch thread - fetches data from Twitter every X minutes. So, every X minutes my Twitter thread downloads a new set of status updates (a Python list). I want to hand this list over to the Main/GUI thread, so that it can update the window with these statuses. I'm assuming that I should be using the signal / slot system to transfer the "statuses" Python list from the Twitter thread, to the Main/GUI thread. So, my question is twofold: How do I send the statuses from the Twitter thread? How do I receive them in the Main/GUI thread? As far as I can tell, PyQt can by default only send PyQt-objects via signals / slots. I think I'm supposed to somehow register a custom signal which I can then send, but the documentation on this that I've found is very unclear to a newbie like me. I have a PyQt book on order, but it won't arrive in another week, and I don't want to wait until then. :-) I'm using PyQt 4.6-1 on Ubuntu Update: This is an excert from the code that doesn't work. First, I try to "connect" the signal ("newStatuses", a name I just made up) to the function self.update_tweet_list in the Main/GUI thread: QtCore.QObject.connect(self.twit_in, QtCore.SIGNAL("newStatuses (statuses)"), self.update_tweet_list) Then, in the Twitter thread, I do this: self.emit(SIGNAL("newStatuses (statuses)"), statuses) When this line is called, I get the following message: QObject::connect: Cannot queue arguments of type 'statuses' (Make sure 'statuses' is registered using qRegisterMetaType().) I did a search for qRegisterMetaType() but I didn't find anything relating to Python that I could understand.

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• Does my API design violate RESTful principles?

  - by peta

  Hello everybody, I'm currently (I try to) designing a RESTful API for a social network. But I'm not sure if my current approach does still accord to the RESTful principles. I'd be glad if some brighter heads could give me some tips. Suppose the following URI represents the name field of a user account: people/{UserID}/profile/fields/name But there are almost hundred possible fields. So I want the client to create its own field views or use predefined ones. Let's suppose that the following URI represents a predefined field view that includes the fields "name", "age", "gender": utils/views/field-views/myFieldView And because field views are kind of higher logic I don't want to mix support for field views into the "people/{UserID}/profile/fields" resource. Instead I want to do the following: utils/views/field-views/myFieldView/{UserID} Though Leonard Richardson & Sam Ruby state in their book "RESTful Web Services" that a RESTful design is somehow like an "extreme object oriented" approach, I think that my approach is object oriented and therefore accords to RESTful principles. Or am I wrong? When not: Are such "object oriented" approaches generally encouraged when used with care and in order to avoid query-based REST-RPC hybrids? Thanks for your feedback in advance, peta

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• How can I connect to server using SSL(secure socket layer) on .NET Compact Framework

  - by net

  Hello. I want to change .NET framework v3.5 to .NET compact framework v3.5. But I can't change SSL Stream class to compact framework version. For resolving this problem, I already read some article and msdn library. http://blogs.msdn.com/cgarcia/archive/2009/08/21/enable-ssl-for-managed-socket-on-windows-mobile.aspx http://blogs.msdn.com/cgarcia/archive/2009/08/22/getting-a-managed-socket-to-talk-ssl.aspx http://msdn.microsoft.com/en-us/library/aa916117.aspx but I got an error that is "Unkown error 0x0ffffff", when invoking 'socket.connect(endPoint)' method based on thease article. In order to find the proper method, I try to use TcpClient class. but i can't solve this problem. When I try to connect to server on .NET compact framework, TcpClient class didn't work(Smart Device project and windows ce). As you can see below, I've got the error. In other hand, this code is work on .NET framework(C# console project). I can't understand why this socket can not access to server. Thanks for reading my question.

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• WPF Databinding problem

  - by costin

  Hi, I'm new to WPF and I have some difficulties when I'm trying to populate a ListView with a list of custom objects. internal class ApplicationCode { public int Code { get; set; } public IEnumerable<string> InstrumentCodes { get; set; } } I have a list of ApplicationCode which I set to ItemsSource to a ListView. I need to display the ApplicationCode.Code as a string and for the rest of the columns a check box which can be checked/unchecked depending if the column name is contained in the InstrumentCodes collection. In order to set the check box I use a converter on databinding: <DataTemplate x:Key="InstrumentCodeTemplate"> <CheckBox IsEnabled="False" IsChecked="{Binding Mode=OneTime, Converter={StaticResource InstrumentSelectionConverter}}" /> </DataTemplate> The problem I have is because I can't know which is the current column at the time of cell data binding and I can't set the ConverterParameter. public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { ApplicationCode appCode = value as ApplicationCode; return appCode != null && appCode.InstrumentCodes.Contains(parameter.ToString()); } There is a way to find out the column index or name? Or there is another way to solve this problem?

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• Sharing large objects between ruby processes without a performance hit

  - by Gdeglin

  I have a Ruby hash that reaches approximately 10 megabytes if written to a file using Marshal.dump. After gzip compression it is approximately 500 kilobytes. Iterating through and altering this hash is very fast in ruby (fractions of a millisecond). Even copying it is extremely fast. The problem is that I need to share the data in this hash between Ruby on Rails processes. In order to do this using the Rails cache (file_store or memcached) I need to Marshal.dump the file first, however this incurs a 1000 millisecond delay when serializing the file and a 400 millisecond delay when serializing it. Ideally I would want to be able to save and load this hash from each process in under 100 milliseconds. One idea is to spawn a new Ruby process to hold this hash that provides an API to the other processes to modify or process the data within it, but I want to avoid doing this unless I'm certain that there are no other ways to share this object quickly. Is there a way I can more directly share this hash between processes without needing to serialize or deserialize it? Here is the code I'm using to generate a hash similar to the one I'm working with: @a = [] 0.upto(500) do |r| @a[r] = [] 0.upto(10_000) do |c| if rand(10) == 0 @a[r][c] = 1 # 10% chance of being 1 else @a[r][c] = 0 end end end @c = Marshal.dump(@a) # 1000 milliseconds Marshal.load(@c) # 400 milliseconds

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• passing value of index number to different php file.

  - by tooepic

  hi, i am a php beginner and have a question for you please. i have a text file with list of first and last names like this: john,smith sam,lewis david,davidson mike,anderson in my sort.php file, it sorts that name list by first name in ascending order with index number, which will display like this: 1. david,davidson 2. john,smith 3. mike,anderson 4. sam,lewis also, in that sort.php file, there's a form for input type=text where you can type index number and a button to delete that index number entered in that text field: <form action="deletename.php" method="post"> <table> <tr valign="top"> <td>Delete: <input type="text" size="2" name="indexnumber" /> </td> <td> <div align="left"> <input type="submit" name="delete" value="Delete" /> </div> </td> </tr> </table> </form> now the question...is there anything i can do in that form to send the value of that index number i entered in the text field? in other word...if i enter 3, what can i do to that form to send the value "mike,anderson" to deletename.php? thanks in advance.

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• Alternative to array_shift function

  - by SoLoGHoST

  Ok, I need keys to be preserved within this array and I just want to shift the 1st element from this array. Actually I know that the first key of this array will always be 1 when I do this: // Sort it by 1st group and 1st layout. ksort($disabled_sections); foreach($disabled_sections as &$grouplayout) ksort($grouplayout); Basically I'd rather not have to ksort it in order to grab this array where the key = 1. And, honestly, I'm not a big fan of array_shift, it just takes to long IMO. Is there another way. Perhaps a way to extract the entire array where $disabled_sections[1] is found without having to do a foreach and sorting it, and array_shift. I just wanna add $disabled[1] to a different array and remove it from this array altogether. While keeping both arrays keys structured the way they are. Technically, it would even be fine to do this: $array = array(); $array = $disabled_sections[1]; But it needs to remove it from $disabled_sections. Can I use something like this approach... $array = array(); $array = $disabled_sections[1]; $disabled_sections -= $disabled_sections[1]; Is something like the above even possible?? Thanks.

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• Detecting Xml namespace fast

  - by Anna Tjsoken

  Hello there, This may be a very trivial problem I'm trying to solve, but I'm sure there's a better way of doing it. So please go easy on me. I have a bunch of XSD files that are internal to our application, we have about 20-30 Xml files that implement datasets based off those XSDs. Some Xml files are small (<100Kb), others are about 3-4Mb with a few being over 10Mb. I need to find a way of working out what namespace these Xml files are in order to provide (something like) intellisense based off the XSD. The implementation of this is not an issue - another developer has written the code for this. But I'm not sure the best (and fastest!) way of detecting the namespace is without the use of XmlDocument (which does a full parse). I'm using C# 3.5 and the documents come through as a Stream (some are remote files). All the files are *.xml (I can detect if it was extension based) but unfortunately the Xml namespace is the only way. Right now I've tried XmlDocument but I've found it to be innefficient and slow as the larger documents are awaiting to be parsed (even the 100Kb docs). public string GetNamespaceForDocument(Stream document); Something like the above is my method signature - overloads include string for "content". Would a RegEx (compiled) pattern be good? How does Visual Studio manage this so efficiently? Another college has told me to find a fast Xml parser in C/C++, parse the content and have a stub that gives back the namespace as its slower in .NET, is this a good idea?

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• SqlDataAdaptor why get a different query

  - by Murat

  Hi All, I have a database reader class. But i want to use this class, sometimes SqlDataAdaptor.Fill() method get another query to Datatable. I look at Query in SqlCommand Instance and my query is correct but returning values from different table? What is the problem? This My Code public static DataTable GetLatestRecords(string TableName, string FilterFieldName, int RecordCount, params DBFieldAndValue[] FilterFields) { DataTable DT = new DataTable(); Type ClassType = typeof(T); string SelectString = string.Format("SELECT TOP ({0}) * FROM {1}", RecordCount, TableName); if (FilterFields.Length > 0) { SelectString += " WHERE 1 = 1 "; for (int index = 0; index < FilterFields.Length; index++) SelectString += FilterFields[index].ToString(index); } SelectString += string.Format(" ORDER BY {0} DESC", FilterFieldName); try { SqlConnection Connection = GetConnection<T>(); SqlCommand Command = new SqlCommand(SelectString, Connection); for (int index = 0; index < FilterFields.Length; index++) Command.Parameters.AddWithValue("@" + FilterFields[index].Field + "_" + index, FilterFields[index].Value); if (Connection.State == ConnectionState.Closed) Connection.Open(); Command.CommandText = SelectString; SqlDataAdapter DA = new SqlDataAdapter(Command); DT.Dispose(); DT = new DataTable(); DA.Fill(DT); if (Connection.State == ConnectionState.Open) Connection.Close(); } catch (Exception ex) { WriteLogStatic(ex.Message); throw new Exception(@"Veritabani islemleri sirasinda hata olustu!\nAyrintilar 'C:\Temp' dizini altindadir.\n" + ex.Message); } return DT; }

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• hover effect jQuery

  - by Ori Cohen

  I have a bunch of li elements that I want to alternate in color using odds and evens, and then highlight based on mouse hover. In order to un-highlight I need to keep track of what the color used to be, odd or even. To do this when I apply the highlight color, I first set an arbitrary attribute to it. Are there any downsides to doing it this way? Is there a better way? Here's the code: <script type="text/javascript"> var init = function(event){ $("li:odd").css({'background-color' : '#eeeeee', 'font-weight' : 'bold'}); $("li:even").css('background-color', '#cccccc'); //initial colors setup $("li").hover( function () //hover over { var current = $(this); current.attr('old-background', current.css('background-color')); current.css('background-color', '#ffee99'); } , function() //hover out { var current = $(this); current.css('background-color', current.attr('old-background')); }) } $(document).ready(init); </script> So is there a better way to do this?

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• Dynamically manipulate php cookies with javascript/jquery

  - by pundit

  Hi guys, I'm currently building a dynamic menu bar(vertical and horizontal). in the default position its vertical. the user have the option to show the horizontal position and hide and vertical. I am currently doing that with javascript/ jquery. in order to keep the menu bar in the horizontal position i am keeping a count with a cookie. the problem is that when i use the click function in javascript i want to change the value of the cookie. i have no knowledge of how to do this. Can anyone assist me with this. all help would be appreciated. <?php setcookie('menu', 1, time()+(86400)); ?> $(document).ready(function() { $('#temp').hide(); if(<?php echo $_COOKIE['menu'];?> == 1){ $('#topmenu').hide(); $('#sidemenu').floating().dropShadow().floating(); $('#sidemenu_bottom').hide(); }else{ $('#topmenu').show(); $('#topmenu').dropShadow(); $('#sidemenu').hide(); $('#sidemenu').removeShadow(); } $('#move').click(function(){ $('#sidemenu').hide("drop",{},2000); $('#sidemenu').removeShadow(); $('#topmenu').show(); $('#topmenu').dropShadow(); $('#sidemenu_bottom').show(); $('#sidemenu_bottom').floating().dropShadow().floating(); }); }); This is what i have so far and the default cookie is working as well as the javascript. its just to change the cookie value now. thanks.

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• Dilemma of Sending a Byte Array from JavaScript to COM.

  - by Voulnet

  Hello there, I'm having a bit of a problem because neither Javascript nor ActiveX (written in C++) are behaving like good little children. All I'm asking them to do is for Javascript to send a byte array and for the ActiveX to receive the byte array correctly in order to do more computation. This is how I declared my byte array in JS, and I verified it inside JS: var arr = new Array(0x00, 0xA4, 0x04, 0x00, 0x10,0xA0, 0x00, 00, 00, 0x18, 0x30, 0x03, 0x01, 00, 00, 00, 00, 00, 00, 00, 00); Javascript sends this array as an argument to an ActiveX method. Here is the tricky part; I want the ActiveX method to receive the byte array as a SAFEARRAY or VARIANT, but I can't get it to work for the life of me. I tried debugging and seeing the contents received inside the ActiveX as both SAFEARRAY or VARIANT, but to no avail. Here is the IDL segment: [id(7), helpstring("NEW Sends APDU to Card and Reads the Response")] HRESULT NewSendAPDU( [in] VARIANT pAPDU, [out, retval]VARIANT* pAPDUResponse); Any help is greatly appreciated. Thanks in advance!

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• How can I get the Hibernate Configuration object from Spring?

  - by Wayne Russell

  Hi, I am trying to obtain Spring-defined Hibernate Configuration and SessionFactory objects in my non-Spring code. The following is the definition in my applicationContext.xml file: Code: <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean"> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop> <prop key="hibernate.show_sql">true</prop> <prop key="hibernate.hbm2ddl.auto">update</prop> <prop key="hibernate.cglib.use_reflection_optimizer">true</prop> <prop key="hibernate.cache.provider_class">org.hibernate.cache.HashtableCacheProvider</prop> </props> </property> <property name="dataSource"> <ref bean="dataSource"/> </property> </bean> If I now call getBean("sessionFactory"), I am returned a $Proxy0 object which appears to be a proxy for the Hibernate SessionFactory object. But that isn't what I want - I need the LocalSessionFactoryBean itself because I need access to the Configuration as well as the SessionFactory. The reason I need the Configuration object is that our framework is able to use Hibernate's dynamic model to automatically insert mappings at runtime; this requires that we change the Configuration and rebuild the SessionFactory. Really, all we're trying to do is obtain the Hibernate config that already exists in Spring so that those of our customers that already have that information in Spring don't need to duplicate it into a hibernate.cfg.xml file in order to use our Hibernate features.

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• Create a delegate from a property getter or setter method

  - by thecoop

  To create a delegate from a method you can use the compile-safe syntax: private int Method() { ... } // and create the delegate to Method... Func<int> d = Method; A property is a wrapper around a getter and setter method, and I want to create a delegate to a property getter method. Something like public int Prop { get; set; } Func<int> d = Prop; // or... Func<int> d = Prop_get; Which doesn't work, unfortunately. I have to create a separate lambda method, which seems unnecessary when the setter method matches the delegate signature anyway: Func<int> d = () => Prop; In order to use the delegate method directly, I have to use nasty reflection, which isn't compile-safe: // something like this, not tested... MethodInfo m = GetType().GetProperty("Prop").GetGetMethod(); Func<int> d = (Func<int>)Delegate.CreateDelegate(typeof(Func<int>), m); Is there any way of creating a delegate on a property getting method directly in a compile-safe way, similar to creating a delegate on a normal method at the top, without needing to use an intermediate lambda method?

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• Why can I run JUnit tests for my Spring project, but not a main method?

  - by FarmBoy

  I am using JDBC to connect to MySQL for a small application. In order to test without altering the real database, I'm using HSQL in memory for JUnit tests. I'm using Spring for DI and DAOs. Here is how I'm configuring my HSQL DataSource <bean id="mockDataSource" class="org.springframework.jdbc.datasource.SingleConnectionDataSource"> <property name="driverClassName" value="org.hsqldb.jdbcDriver"/> <property name="url" value="jdbc:hsqldb:mem:mockSeo"/> <property name="username" value="sa"/> </bean> This works fine for my JUnit tests which use the mock DB. But when I try to run a main method, I find the following error: Error creating bean with name 'mockDataSource' defined in class path resource [beans.xml]: Error setting property values; nested exception is org.springframework.beans.PropertyBatchUpdateException; nested PropertyAccessExceptions (1) are: PropertyAccessException 1: org.springframework.beans.MethodInvocationException: Property 'driverClassName' threw exception; nested exception is java.lang.IllegalStateException: Could not load JDBC driver class [org.hsqldb.jdbcDriver] I'm running from Eclipse, and I'm using the Maven plugin. Is there a reason why this would work as a Test, but not as a main()? I know that the main method itself is not the problem, because it works if I remove all references to the HSQL DataSource from my Spring Configuration file.

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• Defining jUnit Test cases Correctly

  - by Epitaph

  I am new to Unit Testing and therefore wanted to do some practical exercise to get familiar with the jUnit framework. I created a program that implements a String multiplier public String multiply(String number1, String number2) In order to test the multiplier method, I created a test suite consisting of the following test cases (with all the needed integer parsing, etc) @Test public class MultiplierTest { Multiplier multiplier = new Multiplier(); // Test for 2 positive integers assertEquals("Result", 5, multiplier.multiply("5", "1")); // Test for 1 positive integer and 0 assertEquals("Result", 0, multiplier.multiply("5", "0")); // Test for 1 positive and 1 negative integer assertEquals("Result", -1, multiplier.multiply("-1", "1")); // Test for 2 negative integers assertEquals("Result", 10, multiplier.multiply("-5", "-2")); // Test for 1 positive integer and 1 non number assertEquals("Result", , multiplier.multiply("x", "1")); // Test for 1 positive integer and 1 empty field assertEquals("Result", , multiplier.multiply("5", "")); // Test for 2 empty fields assertEquals("Result", , multiplier.multiply("", "")); In a similar fashion, I can create test cases involving boundary cases (considering numbers are int values) or even imaginary values. 1) But, what should be the expected value for the last 3 test cases above? (a special number indicating error?) 2) What additional test cases did I miss? 3) Is assertEquals() method enough for testing the multiplier method or do I need other methods like assertTrue(), assertFalse(), assertSame() etc 4) Is this the RIGHT way to go about developing test cases? How am I "exactly" benefiting from this exercise? 5)What should be the ideal way to test the multiplier method? I am pretty clueless here. If anyone can help answer these queries I'd greatly appreciate it. Thank you.

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• Exporting static data in a DLL

  - by Gayan

  I have a DLL which contains a class with static members. I use __declspec(dllexport) in order to make use of this class's methods. But when I link it to another project and try to compile it, I get "unresolved external symbol" errors for the static data. e.g. In DLL, Test.h class __declspec(dllexport) Test{ protected: static int d; public: static void m(){} } In DLL, Test.cpp #include "Test.h" int Test::d; In the application which uses Test, I call m(). I also tried using __declspec(dllexport) for each method separately but I still get the same link errors for the static members. If I check the DLL (the .lib) using dumpbin, I could see that the symbols have been exported. For instance, the app gives the following error at link time: 1>Main.obj : error LNK2001: unresolved external symbol "protected: static int CalcEngine::i_MatrixRow" (?i_MatrixRow@CalcEngine@@1HA) But the dumpbin of the .lib contains: Version : 0 Machine : 14C (x86) TimeDateStamp: 4BA3611A Fri Mar 19 17:03:46 2010 SizeOfData : 0000002C DLL name : CalcEngine.dll Symbol name : ?i_MatrixRow@CalcEngine@@1HA (protected: static int CalcEngine::i_MatrixRow) Type : data Name type : name Hint : 31 Name : ?i_MatrixRow@CalcEngine@@1HA I can't figure out how to solve this. What am I doing wrong? How can I get over these errors? P.S. The code was originally developed for Linux and the .so/binary combination works without a problem

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• Windows Service Conundrum

  - by Paul Johnson

  All, I have a Custom object which I have written using VB.NET (.net 2.0). The object instantiates its own threading.timer object and carries out a number of background process including periodic interrogation of an oracle database and delivery of emails via smtp according to data detected in the database. The following is the code implemented in the windows service class Public Class IncidentManagerService 'Fakes Private _fakeRepoFactory As IRepoFactory Private _incidentRepo As FakeIncidentRepo Private _incidentDefinitionRepo As FakeIncidentDefinitionRepo Private _incManager As IncidentManager.Session 'Real Private _started As Boolean = False Private _repoFactory As New NHibernateRepoFactory Private _psalertsEventRepo As IPsalertsEventRepo = _repoFactory.GetPsalertsEventRepo() Protected Overrides Sub OnStart(ByVal args() As String) ' Add code here to start your service. This method should set things ' in motion so your service can do its work. If Not _started Then Startup() _started = True End If End Sub Protected Overrides Sub OnStop() 'Tear down class variables in order to ensure the service stops cleanly _incManager.Dispose() _incidentDefinitionRepo = Nothing _incidentRepo = Nothing _fakeRepoFactory = Nothing _repoFactory = Nothing End Sub Private Sub Startup() Dim incidents As IList(Of Incident) = Nothing Dim incidentFactory As New IncidentFactory incidents = IncidentFactory.GetTwoFakeIncidents _repoFactory = New NHibernateRepoFactory _fakeRepoFactory = New FakeRepoFactory(incidents) _incidentRepo = _fakeRepoFactory.GetIncidentRepo _incidentDefinitionRepo = _fakeRepoFactory.GetIncidentDefinitionRepo 'Start an incident manager session _incManager = New IncidentManager.Session(_incidentRepo, _incidentDefinitionRepo, _psalertsEventRepo) _incManager.Start() End Sub End Class After a little bit of experimentation I arrived at the above code in the OnStart method. All functionality passed testing when deployed from VS2005 on my development PC, however when deployed on a true target machine, the service would not start and responds with the following message: "The service on local computer started and then stopped..." Am I going about this the correct way? If not how can I best implement my incident manager within the confines of the Windows Service class. It seems pointless to implement a timer for the incidentmanager because this already implements its own timer... Any assistance much appreciated. Kind Regards Paul J.

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• Ideal Multi-Developer Lamp Stack?

  - by devians

  I would like to build an 'ideal' lamp development stack. Dual Server (Virtualised, ESX) Apache / PHP on one, Databases (MySQL, PgSQL, etc) on the other. User (Developer) Manageable mini environments, or instance. Each developer instance shares the top level config (available modules and default config etc) A developer should have control over their apache and php version for each project. A developer might be able to change minor settings, ie magicquotes on for legacy code. Each project would determine its database provider in its code The idea is that it is one administrate-able server that I can control, and provide globally configured things like APC, Memcached, XDebug etc. Then by moving into subsets for each project, i can allow my users to quickly control their environments for various projects. Essentially I'm proposing the typical system of a developer running their own stack on their own machine, but centralised. In this way I'd hope to avoid problems like Cross OS code problems, database inconsistencies, slightly different installs producing bugs etc. I'm happy to manage this in custom builds from source, but if at all possible it would be great to have a large portion of it managed with some sort of package management. We typically use CentOS, so yum? Has anyone ever built anything like this before? Is there something turnkey that is similar to what I have described? Are there any useful guides I should be reading in order to build something like this?

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• Graph limitations - Should I use Decorator?

  - by Nick Wiggill

  I have a functional AdjacencyListGraph class that adheres to a defined interface GraphStructure. In order to layer limitations on this (eg. acyclic, non-null, unique vertex data etc.), I can see two possible routes, each making use of the GraphStructure interface: Create a single class ("ControlledGraph") that has a set of bitflags specifying various possible limitations. Handle all limitations in this class. Update the class if new limitation requirements become apparent. Use the decorator pattern (DI, essentially) to create a separate class implementation for each individual limitation that a client class may wish to use. The benefit here is that we are adhering to the Single Responsibility Principle. I would lean toward the latter, but by Jove!, I hate the decorator Pattern. It is the epitome of clutter, IMO. Truthfully it all depends on how many decorators might be applied in the worst case -- in mine so far, the count is seven (the number of discrete limitations I've recognised at this stage). The other problem with decorator is that I'm going to have to do interface method wrapping in every... single... decorator class. Bah. Which would you go for, if either? Or, if you can suggest some more elegant solution, that would be welcome. EDIT: It occurs to me that using the proposed ControlledGraph class with the strategy pattern may help here... some sort of template method / functors setup, with individual bits applying separate controls in the various graph-canonical interface methods. Or am I losing the plot?

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• How to build n-layered web architecture with PHP?

  - by Alex

  I have a description and design of a website and I need to redesign it to allow for new requirements. The website's purpose is the offering of government's contracts and bidding opportunities for different businesses.I'm dealing with the 3-tier architecture PHP website comprising of the user-interface tier(client's web browser),business logic layer(Apache web server with PHP engine in it and a couple of applications running within a web server as well) and a database layer(local mysql database). Now,i need to redesign it to su???rt distributed n-tier architecture and specify how I would go about it.After long hours of research i came to this solution: business logic should be separated into presentation and purely business logic tier to allow for n-layer architecture(user-interface,presentation tier,b.logic and data tier).I have decided to use ??? just for the presentation(since the original existing website is in PHP) and use it within apache web server.In the business logic i want to use J2?? implementation technology instead of implementing it in PHP(i.e using Zend app.server and smarty template) cz J2EE can provide much more essential container services which are essential for business logic,its robustness,maintainability and different critical business operations which will be carried out by the g?v?rnment's website.So,particularly,i want to use J??ss app.server with ?J? business objects in it which would provide all the b.logic in java and would interact with the database and so forth.In order to connect PHP on a web server with java on app.server i'm gonna use PHP/Java bridge API (or maybe Quercus or SOAP is better?).Finally,i have my data tier with mysql which will communicate with b.logic via JD??.Payment system application in ???.server is gonna use S??? to talk with credit card company. From your professional point of view,does it sound like a good way of redesigning the original website to allow for n-tier architecture considering the specifics of the website and the criticality of its operations?(payment system is included in it)or u would personally prefer to use PHP business objects for business logic as well instead of J2EE?If you have any wiser recommendation or some alternative,please let me know what is right or wrong in my current solution. H??? to hear your professional advice very s??n (I'm new to the area of web development) Thanks in advance

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• UIScrollView notifications

  - by ryyst

  Hi, I'm coding an app that works much like Apple's Weather.app: There's a UIPageControl at the bottom and a UIScrollView in the middle of the screen. In my code, I implemented the - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView method to figure out when the user did move to a new page. If they move to a new page, I load the adjacent pages' data, as to make further page-switching faster. (In one of Apple's examples, the - (void)scrollViewDidScroll:(UIScrollView *)sender is used, but that causes my app to shortly hang when loading a new page, so it's not suitable.) That code works very well. I'm using scrollRectToVisible:: to programmatically scroll inside the scrollview when the user clicks the UIPageControl. The problem is that the scrollRectToVisible: doesn't post a notification to the UIScrollViewDelegate when it's done scrolling - so the code responsible for loading adjacent pages never get's called when using the UIPageControl. Is there any way to make the UIScrollView notify its delegate when it gets called by the scrollRectToVisible: method? Or will I have to use threads in order to prevent my app from freezing? Thanks! -- Ry

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• Secure Password Storage and Transfer

  - by Andras Zoltan

  I'm developing a new user store for my organisation and am now tackling password storage. The concepts of salting, HMAC etc are all fine with me - and want to store the users' passwords either salted and hashed, HMAC hashed, or HMAC salted and hashed - not sure what the best way will be - but in theory it won't matter as it will be able to change over time if required. I want to have an XML & JSON service that can act as a Security Token Service for client-side apps. I've already developed one for another system, which requires that the client double-encrypts a clear-text password using SHA1 first and then HMACSHA1 using a 128 unique key (or nonce) supplied by the server for that session only. I'd like to repeat this technique for the new system - upgrading the algo to SHA256 (chosen since implementations are readily available for all aforementioned platforms - and it's much stronger than SHA1) - but there is a problem. If I'm storing the password as a salted hash in the user-store, the client will need to be sent that salt in order to construct the correct hash before being HMACd with the unique session key. This would completely go against the point of using a salt in the first place. Equally, if I don't use salt for password storage, but instead use HMAC, it's still the same problem. At the moment, the only solution I can see is to use naked SHA256 hashing for the password in the user store, so that I can then use this as a starting point on both the server and the client for a more secure salted/hmacd password transfer for the web service. This still leaves the user store vulnerable to a dictionary attack were it ever to be accessed; and however unlikely that might be - assuming it will never happen simply doesn't sit well with me. Greatly appreciate any input.

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• Database design for credit based purchases

  - by FreshCode

  I need an elegant way to implement credit-based purchases for an online store with a small variety of products which can be purchased using virtual credit or real currency. Alternatively, products could only be priced in credits. Previous work I have implemented credit-based purchasing before using different product types (eg. Credit, Voucher or Music) with post-order processing to assign purchased credit to users in the form of real currency, which could subsequently be used to discount future orders' charge totals. This worked fairly well as a makeshift solution, but did not succeed in disconnecting the virtual currency from the real currency, which is what I'd like to do, since spending credits is psychologically easier for customers than spending real currency. Design I need guidance on designing the database correctly with support for the simultaneous bulk purchase of credits at a discount along with real currency products. Alternatively, should all products be priced in credits and only credit have a real currency value? Existing Database Design Partial Products table: ProductId Title Type UnitPrice SalePrice Partial Orders table: OrderId UserId (related to Users table, not shown) Status Value Total Partial OrderItems table (similar to CartItems table): OrderItemId OrderId (related to Orders table) ProductId (related to Products table) Quantity UnitPrice SalePrice Prospective UserCredits table: CreditId UserId (related to Users table, not shown) Value (+/- value. Summed over time to determine saldo.) Date I'm using ASP.NET MVC and LINQ-to-SQL on a SQL Server database.

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• sql 2008 sqldmo alternative

  - by alexdelpiero

  Hi! I previously was using sqldmo to automatically generate scripts from the databse. Now I upgraded to sql server 2008 and I don’t want to use this feature anymore since Microsoft will be dropping this feature off. Is there any other alternative I can use to connect to a server and generate scripts automatically from a database? Any answer is welcome. Thanks in advance. This is the procedure i was previously using: CREATE PROC GenerateSP ( @server varchar(30) = null, @uname varchar(30) = null, @pwd varchar(30) = null, @dbname varchar(30) = null, @filename varchar(200) = 'c:\script.sql' ) AS DECLARE @object int DECLARE @hr int DECLARE @return varchar(200) DECLARE @exec_str varchar(2000) DECLARE @spname sysname SET NOCOUNT ON -- Sets the server to the local server IF @server is NULL SELECT @server = @@servername -- Sets the database to the current database IF @dbname is NULL SELECT @dbname = db_name() -- Sets the username to the current user name IF @uname is NULL SELECT @uname = SYSTEM_USER -- Create an object that points to the SQL Server EXEC @hr = sp_OACreate 'SQLDMO.SQLServer', @object OUT IF @hr < 0 BEGIN PRINT 'error create SQLOLE.SQLServer' RETURN END -- Connect to the SQL Server IF @pwd is NULL BEGIN EXEC @hr = sp_OAMethod @object, 'Connect', NULL, @server, @uname IF @hr < 0 BEGIN PRINT 'error Connect' RETURN END END ELSE BEGIN EXEC @hr = sp_OAMethod @object, 'Connect', NULL, @server, @uname, @pwd IF @hr < 0 BEGIN PRINT 'error Connect' RETURN END END --Verify the connection EXEC @hr = sp_OAMethod @object, 'VerifyConnection', @return OUT IF @hr < 0 BEGIN PRINT 'error VerifyConnection' RETURN END SET @exec_str = 'DECLARE script_cursor CURSOR FOR SELECT name FROM ' + @dbname + '..sysobjects WHERE type = ''P'' ORDER BY Name' EXEC (@exec_str) OPEN script_cursor FETCH NEXT FROM script_cursor INTO @spname WHILE (@@fetch_status < -1) BEGIN SET @exec_str = 'Databases("'+ @dbname +'").StoredProcedures("'+RTRIM(UPPER(@spname))+'").Script(74077,"'+ @filename +'")' EXEC @hr = sp_OAMethod @object, @exec_str, @return OUT IF @hr < 0 BEGIN PRINT 'error Script' RETURN END FETCH NEXT FROM script_cursor INTO @spname END CLOSE script_cursor DEALLOCATE script_cursor -- Destroy the object EXEC @hr = sp_OADestroy @object IF @hr < 0 BEGIN PRINT 'error destroy object' RETURN END GO

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