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  • Writing an ostream filter?

    - by shoosh
    I'd like to write a simple ostream which wraps an argument ostream and changes the stream in some way before passing it on to the argument stream. The transformation is something simple like changing a letter or erasing a word What would a simple class inheriting from ostream look like? What methods should I override?

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  • Tapestry5 display grid component using a hashmap

    - by Eldred
    Hi there I am trying to attempt to display a hashmap using a grid component. If I use List list = CollectionFactory.newList(MyHashMap) it returns a list however on my template page I see Empty and false when passing my parameter t:souce="list" to my grid component, therefore my grid component only returns one row. Some code snippets would be a great help. Many thanks

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  • distinction between using .text and .value in VBA access

    - by every_answer_gets_a_point
    i am passing the textbox1.text values into a query and sometimes into a string sometimes i say this: dim combor1 as string combor1 = comboReason1.Text how do i know when i should put combor1=comboreason1.value ?? also why do i need to set focus for a control to reference its property? that doesn't make sense to me also when i set combor4 = comboReason4.Value and the .value is null, then i get an error about invalid use of null please help!

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  • regarding object recycling

    - by ajaycv
    I have a question. What is wrong with regards to the below code: ArrayList tempList2 = new ArrayList(); tempList2 = getXYZ(tempList1, tempList2); //method getXYZ getXYZ(ArrayList tempList1, ArrayList tempList2) { //does some logic and adds objects into tempList2 return tempList2; } The code will get executed but it seems by passing tempList2 to the getXYZ method argument, it is doing object recycling. My question is, Is recycling the tempList2 arraylist object correct?

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  • Creating a good search solution

    - by Daniel
    I have an app where users have a role,a username,faculty and so on.When I'm looking for a list of users by their role or faculty or anything they have in common I can call (among others possible) @users = User.find_by_role(params[:role]) #or @users = User.find_by_shift(params[:shift]) So it keeps the system Class.find_by_property So the question is: What if at different points users lists should be generated based on different properties.I mean: I'm passing from different links params[:role] or params[:faculty] or params[:department] to my list action in my users controller.As I see it all has to be in that action,but which parameter should the search be made by?

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  • x11vnc working in Ubuntu 10.10

    - by pablorc
    I'm trying to start x11vnc in a Ubuntu 10.10 (my server is in Amazon EC2), but I have the next error $ sudo x11vnc -forever -usepw -httpdir /usr/share/vnc-java/ -httpport 5900 -auth /usr/sbin/gdm 25/11/2010 13:29:51 passing arg to libvncserver: -httpport 25/11/2010 13:29:51 passing arg to libvncserver: 5900 25/11/2010 13:29:51 -usepw: found /home/ubuntu/.vnc/passwd 25/11/2010 13:29:51 x11vnc version: 0.9.10 lastmod: 2010-04-28 pid: 3504 25/11/2010 13:29:51 XOpenDisplay(":0.0") failed. 25/11/2010 13:29:51 Trying again with XAUTHLOCALHOSTNAME=localhost ... 25/11/2010 13:29:51 *************************************** 25/11/2010 13:29:51 *** XOpenDisplay failed (:0.0) *** x11vnc was unable to open the X DISPLAY: ":0.0", it cannot continue. *** There may be "Xlib:" error messages above with details about the failure. Some tips and guidelines: ** An X server (the one you wish to view) must be running before x11vnc is started: x11vnc does not start the X server. (however, see the -create option if that is what you really want). ** You must use -display <disp>, -OR- set and export your $DISPLAY environment variable to refer to the display of the desired X server. - Usually the display is simply ":0" (in fact x11vnc uses this if you forget to specify it), but in some multi-user situations it could be ":1", ":2", or even ":137". Ask your administrator or a guru if you are having difficulty determining what your X DISPLAY is. ** Next, you need to have sufficient permissions (Xauthority) to connect to the X DISPLAY. Here are some Tips: - Often, you just need to run x11vnc as the user logged into the X session. So make sure to be that user when you type x11vnc. - Being root is usually not enough because the incorrect MIT-MAGIC-COOKIE file may be accessed. The cookie file contains the secret key that allows x11vnc to connect to the desired X DISPLAY. - You can explicitly indicate which MIT-MAGIC-COOKIE file should be used by the -auth option, e.g.: x11vnc -auth /home/someuser/.Xauthority -display :0 x11vnc -auth /tmp/.gdmzndVlR -display :0 you must have read permission for the auth file. See also '-auth guess' and '-findauth' discussed below. ** If NO ONE is logged into an X session yet, but there is a greeter login program like "gdm", "kdm", "xdm", or "dtlogin" running, you will need to find and use the raw display manager MIT-MAGIC-COOKIE file. Some examples for various display managers: gdm: -auth /var/gdm/:0.Xauth -auth /var/lib/gdm/:0.Xauth kdm: -auth /var/lib/kdm/A:0-crWk72 -auth /var/run/xauth/A:0-crWk72 xdm: -auth /var/lib/xdm/authdir/authfiles/A:0-XQvaJk dtlogin: -auth /var/dt/A:0-UgaaXa Sometimes the command "ps wwwwaux | grep auth" can reveal the file location. Starting with x11vnc 0.9.9 you can have it try to guess by using: -auth guess (see also the x11vnc -findauth option.) Only root will have read permission for the file, and so x11vnc must be run as root (or copy it). The random characters in the filenames will of course change and the directory the cookie file resides in is system dependent. See also: http://www.karlrunge.com/x11vnc/faq.html I've already tried with some -auth options but the error persist. I have gdm running. Thank you in advance

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  • SignalR cannot read property client of undefined

    - by polonskyg
    I'm trying to add SignalR to my project (ASPNET MVC 4). But I can't make it work. In the below image you can see the error I'm receiving. I've read a lot of stackoverflow posts but none of them is resolving my issue. This is what I did so far: 1) Ran Install-Package Microsoft.AspNet.SignalR -Pre 2) Added RouteTable.Routes.MapHubs(); in Global.asax.cs Application_Start() 3) If I go to http://localhost:9096/Gdp.IServer.Web/signalr/hubs I can see the file content 4) Added <modules runAllManagedModulesForAllRequests="true"/> to Web.Config 5) Created folder Hubs in the root of the MVC application 6) Moved jquery and signalR scripts to /Scripts/lib folder (I'm not using jquery 1.6.4, I'm using the latest) This is my Index.cshtml <h2>List of Messages</h2> <div class="container"> <input type="text" id="message" /> <input type="button" id="sendmessage" value="Send" /> <input type="hidden" id="displayname" /> <ul id="discussion"> </ul> </div> @section pageScripts { <!--Reference the SignalR library. --> <script src="@Url.Content("~/Scripts/jquery.signalR-1.0.0-rc1.min.js")" type="text/javascript"></script> <!--Reference the autogenerated SignalR hub script. --> <script type="text/javascript" src="~/signalr/hubs"></script> <script src="@Url.Content("~/Scripts/map.js")" type="text/javascript"></script> } This is my IServerHub.cs file (located inside Hubs folder) namespace Gdp.IServer.Ui.Web.Hubs { using Microsoft.AspNet.SignalR.Hubs; [HubName("iServerHub")] public class IServerHub : Hub { public void Send(string name, string message) { Clients.All.broadcastMessage(name, message); } } } And this is map.js $(function () { // Declare a proxy to reference the hub. var clientServerHub = $.connection.iServerHub; // Create a function that the hub can call to broadcast messages. clientServerHub.client.broadcastMessage = function (name, message) { $('#discussion').append('<li><strong>' + name + '</strong>:&nbsp;&nbsp;' + message + '</li>'); }; // Get the user name and store it to prepend to messages. $('#displayname').val(prompt('Enter your name:', '')); // Set initial focus to message input box. $('#message').focus(); // Start the connection. $.connection.hub.start().done(function () { $('#sendmessage').click(function () { // Html encode display name and message. var encodedName = $('<div />').text($('#displayname').val()).html(); var encodedMsg = $('<div />').text($('#message').val()).html(); // Call the Send method on the hub. clientServerHub.server.send(encodedName, encodedMsg); // Clear text box and reset focus for next comment. $('#message').val('').focus(); }); }); }); The DLL's I see references for SignalR are: Microsoft.AspNet.SignalR.Core Microsoft.AspNet.SignalR.Owin Microsoft.AspNet.SignalR.SystemWeb Any ideas how to get it work? Should I make any change because the scripts are in /Script/lib folder? NOTE I'm following the instruction found here on how to set up Windsor Castle to make it work with SignalR, and again, seems that the proxy cannot be created and I'm getting the same error: Cannot read property client of undefined meaning that the proxy to the hub was not created This is how I have it in the server public class IncidentServerHub : Hub and like this in the client var clientServerHub = $.connection.incidentServerHub; Again, I can see the dynamically created file here: /GdpSoftware.Server.Web/signalr/hubs So, Why the proxy is not created? Thanks in advance!!! Guillermo.

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  • EF4 POCO WCF Serialization problems (no lazy loading, proxy/no proxy, circular references, etc)

    - by kdawg
    OK, I want to make sure I cover my situation and everything I've tried thoroughly. I'm pretty sure what I need/want can be done, but I haven't quite found the perfect combination for success. I'm utilizing Entity Framework 4 RTM and its POCO support. I'm looking to query for an entity (Config) that contains a many-to-many relationship with another entity (App). I turn off lazy loading and disable proxy creation for the context and explicitly load the navigation property (either through .Include() or .LoadProperty()). However, when the navigation property is loaded (that is, Apps is loaded for a given Config), the App objects that were loaded already contain references to the Configs that have been brought to memory. This creates a circular reference. Now I know the DataContractSerializer that WCF uses can handle circular references, by setting the preserveObjectReferences parameter to true. I've tried this with a couple of different attribute implementations I've found online. It is needed to prevent the "the object graph contains circular references and cannot be serialized" error. However, it doesn't prevent the serialization of the entire graph, back and forth between Config and App. If I invoke it via WcfTestClient.exe, I get a stackoverflow (ha!) exception from the client and I'm hosed. I get different results from different invocation environments (C# unit test with a local reference to the web service appears to work ok though I still can drill back and forth between Configs and Apps endlessly, but calling it from a coldfusion environment only returns the first Config in the list and errors out on the others.) My main goal is to have a serialized representation of the graph I explicitly load from EF (ie: list of Configs, each with their Apps, but no App back to Config navigation.) NOTE: I've also tried using the ProxyDataContractResolver technique and keeping the proxy creation enabled from my context. This blows up complaining about unknown types encountered. I read that the ProxyDataContractResolver didn't fully work in Beta2, but should work in RTM. For some reference, here is roughly how I'm querying the data in the service: var repo = BootStrapper.AppCtx["AppMeta.ConfigRepository"] as IRepository<Config>; repo.DisableLazyLoading(); repo.DisableProxyCreation(); //var temp2 = repo.Include(cfg => cfg.Apps).Where(cfg => cfg.Environment.Equals(environment)).ToArray(); var temp2 = repo.FindAll(cfg => cfg.Environment.Equals(environment)).ToArray(); foreach (var cfg in temp2) { repo.LoadProperty(cfg, c => c.Apps); } return temp2; I think the crux of my problem is when loading up navigation properties for POCO objects from Entity Framework 4, it prepopulates navigation properties for objects already in memory. This in turn hoses up the WCF serialization, despite every effort made to properly handle circular references. I know it's a lot of information, but it's really standing in my way of going forward with EF4/POCO in our system. I've found several articles and blogs touching upon these subjects, but for the life of me, I cannot resolve this issue. Feel free to simply ask questions and help me brainstorm this situation. PS: For the sake of being thorough, I am injecting the WCF services using the HEAD build of Spring.NET for the fix to Spring.ServiceModel.Activation.ServiceHostFactory. However I don't think this is the source of the problem.

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  • Bluetooth RFCOMM / SDP connection to a RS232 adapter in android

    - by ThePosey
    Hello All, I am trying to use the Bluetooth Chat sample API app that google provides to connect to a bluetooth RS232 adapter hooked up to another device. Here is the app for reference: http://developer.android.com/resources/samples/BluetoothChat/index.html And here is the spec sheet for the RS232 connector just for reference: http://serialio.com/download/Docs/BlueSnap-guide-4.77_Commands.pdf Well the problem is that when I go to connect to the device with: mmSocket.connect(); (BluetoothSocket::connect()) I always get an IOException error thrown by the connect() method. When I do a toString on the exception I get "Service discovery failed". My question is mostly what are the cases that would cause an IOException to get thrown in the connect method? I know those are in the source somewhere but I don't know exactly how the java layer that you write apps in and the C/C++ layer that contains the actual stacks interface. I know that it uses the bluez bluetooth stack which is written in C/C++ but not sure how that ties into the java layer which is what I would think is throwing the exception. Any help on pointing me to where I can try to dissect this issue would be incredible. Also just to note I am able to pair with the RS232 adapter just fine but I am never able to actually connect. Here is the logcat output for more reference: I/ActivityManager( 1018): Displayed activity com.example.android.BluetoothChat/.DeviceListActivity: 326 ms (total 326 ms) E/BluetoothService.cpp( 1018): stopDiscoveryNative: D-Bus error in StopDiscovery: org.bluez.Error.Failed (Invalid discovery session) D/BluetoothChat( 1729): onActivityResult -1 D/BluetoothChatService( 1729): connect to: 00:06:66:03:0C:51 D/BluetoothChatService( 1729): setState() STATE_LISTEN - STATE_CONNECTING E/BluetoothChat( 1729): + ON RESUME + I/BluetoothChat( 1729): MESSAGE_STATE_CHANGE: STATE_CONNECTING I/BluetoothChatService( 1729): BEGIN mConnectThread E/BluetoothService.cpp( 1018): stopDiscoveryNative: D-Bus error in StopDiscovery: org.bluez.Error.Failed (Invalid discovery session) E/BluetoothEventLoop.cpp( 1018): event_filter: Received signal org.bluez.Device:PropertyChanged from /org/bluez/1498/hci0/dev_00_06_66_03_0C_51 I/BluetoothChatService( 1729): CONNECTION FAIL TOSTRING: java.io.IOException: Service discovery failed D/BluetoothChatService( 1729): setState() STATE_CONNECTING - STATE_LISTEN D/BluetoothChatService( 1729): start D/BluetoothChatService( 1729): setState() STATE_LISTEN - STATE_LISTEN I/BluetoothChat( 1729): MESSAGE_STATE_CHANGE: STATE_LISTEN V/BluetoothEventRedirector( 1080): Received android.bleutooth.device.action.UUID I/NotificationService( 1018): enqueueToast pkg=com.example.android.BluetoothChat callback=android.app.ITransientNotification$Stub$Proxy@446327c8 duration=0 I/BluetoothChat( 1729): MESSAGE_STATE_CHANGE: STATE_LISTEN E/BluetoothEventLoop.cpp( 1018): event_filter: Received signal org.bluez.Device:PropertyChanged from /org/bluez/1498/hci0/dev_00_06_66_03_0C_51 V/BluetoothEventRedirector( 1080): Received android.bleutooth.device.action.UUID The device I'm trying to connect to is the 00:06:66:03:0C:51 which I can scan for and apparently pair with just fine. The below is merged from a similar question which was successfully resolved by the selected answer here: How can one connect to an rfcomm device other than another phone in Android? The Android API provides examples of using listenUsingRfcommWithServiceRecord() to set up a socket and createRfcommSocketToServiceRecord() to connect to that socket. I'm trying to connect to an embedded device with a BlueSMiRF Gold chip. My working Python code (using the PyBluez library), which I'd like to port to Android, is as follows: sock = bluetooth.BluetoothSocket(proto=bluetooth.RFCOMM) sock.connect((device_addr, 1)) return sock.makefile() ...so the service to connect to is simply defined as channel 1, without any SDP lookup. As the only documented mechanism I see in the Android API does SDP lookup of a UUID, I'm slightly at a loss. Using "sdptool browse" from my Linux host comes up empty, so I surmise that the chip in question simply lacks SDP support.

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  • Build problems when adding `__str__` method to Boost Python C++ class

    - by Rickard
    I have started to play around with boost python a bit and ran into a problem. I tried to expose a C++ class to python which posed no problems. But I can't seem to manage to implement the __str__ functionality for the class without getting build errors I don't understand. I'm using boost 1_42 prebuild by boostpro. I build the library using cmake and the vs2010 compiler. I have a very simple setup. The header-file (tutorial.h) looks like the following: #include <iostream> namespace TestBoostPython{ class TestClass { private: double m_x; public: TestClass(double x); double Get_x() const; void Set_x(double x); }; std::ostream &operator<<(std::ostream &ostr, const TestClass &ts); }; and the corresponding cpp-file looks like: #include <boost/python.hpp> #include "tutorial.h" using namespace TestBoostPython; TestClass::TestClass(double x) { m_x = x; } double TestClass::Get_x() const { return m_x; } void TestClass::Set_x(double x) { m_x = x; } std::ostream &operator<<(std::ostream &ostr, TestClass &ts) { ostr << ts.Get_x() << "\n"; return ostr; } BOOST_PYTHON_MODULE(testme) { using namespace boost::python; class_<TestClass>("TestClass", init<double>()) .add_property("x", &TestClass::Get_x, &TestClass::Set_x) .def(str(self)) ; } The CMakeLists.txt looks like the following: CMAKE_MINIMUM_REQUIRED(VERSION 2.8) project (testme) FIND_PACKAGE( Boost REQUIRED ) FIND_PACKAGE( Boost COMPONENTS python REQUIRED ) FIND_PACKAGE( PythonLibs REQUIRED ) set(Boost_USE_STATIC_LIBS OFF) set(Boost_USE_MULTITHREAD ON) INCLUDE_DIRECTORIES(${Boost_INCLUDE_DIRS}) INCLUDE_DIRECTORIES ( ${PYTHON_INCLUDE_PATH} ) add_library(testme SHARED tutorial.cpp) target_link_libraries(testme ${Boost_PYTHON_LIBRARY}) target_link_libraries(testme ${PYTHON_LIBRARY} The build error I get is the following: Compiling... tutorial.cpp C:\Program Files (x86)\boost\boost_1_42\boost/python/def_visitor.hpp(31) : error C2780: 'void boost::python::api::object_operators::visit(ClassT &,const char *,const boost::python::detail::def_helper &) const' : expects 3 arguments - 1 provided with [ U=boost::python::api::object ] C:\Program Files (x86)\boost\boost_1_42\boost/python/object_core.hpp(203) : see declaration of 'boost::python::api::object_operators::visit' with [ U=boost::python::api::object ] C:\Program Files (x86)\boost\boost_1_42\boost/python/def_visitor.hpp(67) : see reference to function template instantiation 'void boost::python::def_visitor_access::visit,classT>(const V &,classT &)' being compiled with [ DerivedVisitor=boost::python::api::object, classT=boost::python::class_, V=boost::python::def_visitor ] C:\Program Files (x86)\boost\boost_1_42\boost/python/class.hpp(225) : see reference to function template instantiation 'void boost::python::def_visitor::visit>(classT &) const' being compiled with [ DerivedVisitor=boost::python::api::object, W=TestBoostPython::TestClass, classT=boost::python::class_ ] .\tutorial.cpp(29) : see reference to function template instantiation 'boost::python::class_ &boost::python::class_::def(const boost::python::def_visitor &)' being compiled with [ W=TestBoostPython::TestClass, U=boost::python::api::object, DerivedVisitor=boost::python::api::object ] Does anyone have any idea on what went wrrong? If I remove the .def(str(self)) part from the wrapper code, everything compiles fine and the class is usable from python. I'd be very greatful for assistance. Thank you, Rickard

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  • How can I generate a client proxy for a WCF service with an HTTPS endpoint?

    - by ng5000
    Might be the same issue as this previuos question: WCF Proxy but not sure... I have an HTTPS service connfigured to use transport security and, I hope, Windows credentials. The service is only accessed internally (i.e. within the intranet). The configuration is as follows: <configuration> <system.serviceModel> <services> <service name="WCFTest.CalculatorService" behaviorConfiguration="WCFTest.CalculatorBehavior"> <host> <baseAddresses> <add baseAddress = "https://localhost:8000/WCFTest/CalculatorService/" /> </baseAddresses> </host> <endpoint address ="basicHttpEP" binding="basicHttpBinding" contract="WCFTest.ICalculatorService" bindingConfiguration="basicHttpBindingConfig"/> <endpoint address="mex" binding="mexHttpsBinding" contract="IMetadataExchange"/> </service> </services> <bindings> <basicHttpBinding> <binding name="basicHttpBindingConfig"> <security mode="Transport"> <transport clientCredentialType = "Windows"/> </security> </binding> </basicHttpBinding> </bindings> <behaviors> <serviceBehaviors> <behavior name="WCFTest.CalculatorBehavior"> <serviceAuthorization impersonateCallerForAllOperations="false" principalPermissionMode="UseWindowsGroups" /> <serviceCredentials > <windowsAuthentication allowAnonymousLogons="false" includeWindowsGroups="true" /> </serviceCredentials> <serviceMetadata httpsGetEnabled="True"/> <serviceDebug includeExceptionDetailInFaults="False" /> </behavior> </serviceBehaviors> </behaviors> </system.serviceModel> </configuration> When I run the service I can't see the service in IE. I get a "this page can not be displayed" error. If I try and create a client in VS2008 via the "add service reference" wizard I get this error: There was an error downloading 'https://localhost:8000/WCFTest/CalculatorService/'. There was an error downloading 'https://localhost:8000/WCFTest/CalculatorService/'. The underlying connection was closed: An unexpected error occurred on a send. Authentication failed because the remote party has closed the transport stream. Metadata contains a reference that cannot be resolved: 'https://localhost:8000/WCFTest/CalculatorService/'. An error occurred while making the HTTP request to https://localhost:8000/WCFTest/CalculatorService/. This could be due to the fact that the server certificate is not configured properly with HTTP.SYS in the HTTPS case. This could also be caused by a mismatch of the security binding between the client and the server. The underlying connection was closed: An unexpected error occurred on a send. Authentication failed because the remote party has closed the transport stream. If the service is defined in the current solution, try building the solution and adding the service reference again. I think I'm missing some fundamental basics here. Do I need to set up some certificates? Or should it all just work as it seems to do when I use NetTcpBinding? Thanks

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  • linker error when using tr1::regex

    - by Max
    Hello. I've got a program that uses tr1::regex, and while it compiles, it gives me very verbose linker errors. Here's my header file MapObject.hpp: #include <iostream> #include <string> #include <tr1/regex> #include "phBaseObject.hpp" using std::string; namespace phObject { class MapObject: public phBaseObject { private: string color; // must be a hex string represented as "#XXXXXX" static const std::tr1::regex colorRX; // enforces the rule above public: void setColor(const string&); (...) }; } Here's my implementation: #include <iostream> #include <string> #include <tr1/regex> #include "MapObject.hpp" using namespace std; namespace phObject { const tr1::regex MapObject::colorRX("#[a-fA-F0-9]{6}"); void MapObject::setColor(const string& c) { if(tr1::regex_match(c.begin(), c.end(), colorRX)) { color = c; } else cerr << "Invalid color assignment (" << c << ")" << endl; } (...) } and now for the errors: max@max-desktop:~/Desktop/Development/CppPartyHack/PartyHack/lib$ g++ -Wall -std=c++0x MapObject.cpp /tmp/cce5gojG.o: In function std::tr1::basic_regex<char, std::tr1::regex_traits<char> >::basic_regex(char const*, unsigned int)': MapObject.cpp:(.text._ZNSt3tr111basic_regexIcNS_12regex_traitsIcEEEC1EPKcj[std::tr1::basic_regex<char, std::tr1::regex_traits<char> >::basic_regex(char const*, unsigned int)]+0x61): undefined reference tostd::tr1::basic_regex ::_M_compile()' /tmp/cce5gojG.o: In function bool std::tr1::regex_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, char, std::tr1::regex_traits<char> >(__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::tr1::basic_regex<char, std::tr1::regex_traits<char> > const&, std::bitset<11u>)': MapObject.cpp:(.text._ZNSt3tr111regex_matchIN9__gnu_cxx17__normal_iteratorIPKcSsEEcNS_12regex_traitsIcEEEEbT_S8_RKNS_11basic_regexIT0_T1_EESt6bitsetILj11EE[bool std::tr1::regex_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, char, std::tr1::regex_traits<char> >(__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::tr1::basic_regex<char, std::tr1::regex_traits<char> > const&, std::bitset<11u>)]+0x53): undefined reference tobool std::tr1::regex_match<__gnu_cxx::__normal_iterator, std::allocator , std::allocator, std::allocator , char, std::tr1::regex_traits (__gnu_cxx::__normal_iterator, std::allocator , __gnu_cxx::__normal_iterator, std::allocator , std::tr1::match_results<__gnu_cxx::__normal_iterator, std::allocator , std::allocator, std::allocator &, std::tr1::basic_regex const&, std::bitset<11u)' collect2: ld returned 1 exit status I can't really make heads or tails of this, except for the undefined reference to std::tr1::basic_regex near the beginning. Anyone know what's going on?

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  • Unable to host WCF service correctly in IIS7

    - by user206736
    I have a WCF Service library written in .NET 4.0. I have a WCF application (in order to host this service in IIS) within the same solution. It contains the WCF library assembly reference and a service.svc file pointing to the service from the library along with a web.config that is a replica of the WCF service library's app.config. The WCF application is set to host the service in IIS7 (the virtual directory has been set). The same solution contains an ASP.NET Webforms solution to which I have added a service reference pointing to the WCF service I hosted in IIS (as mentioned). When i start an instance of this ASP.NET Web application, I get a message saying that "The WCF service has been hosted" and the ASP.NET application can access the data from it correctly. However, when i try and access this data via a service reference added to an MVC 2 Web Application on the same machine in a different solution (pointing to the service hosted in IIS), I get a "The remote server returned an error: (405) Method Not Allowed." protocol exception . However, the MVC application is able to access the service data if I manually invoke an instance of the WCF Application that I was using to host the WCF Service Library from the other solution. I am using VS2010 Beta 2 as my development IDE. I have been stuck with this issue for a while now. Any help would be appreciated. My service config is as follows:- <system.serviceModel> <services> <service behaviorConfiguration="CruxServices.BasicSearchServiceBehavior" name="CruxServices.BasicSearch.BasicSearch"> <endpoint address="" binding="wsHttpBinding" name="WSBindingEndpoint" bindingConfiguration="WSBindingConfig" contract="CruxServices.BasicSearch.Interfaces.IPropertyListFilter"> <identity> <dns value="localhost" /> </identity> </endpoint> <endpoint address="mex" binding="mexHttpBinding" name="MexEndpoint" contract="IMetadataExchange" /> <host> <baseAddresses> <add baseAddress="http://localhost/CruxServices" /> </baseAddresses> </host> </service> </services> <behaviors> <serviceBehaviors> <behavior name="CruxServices.BasicSearchServiceBehavior"> <serviceMetadata httpGetEnabled="true" /> <serviceDebug includeExceptionDetailInFaults="false" /> </behavior> </serviceBehaviors> </behaviors> <bindings> <wsHttpBinding> <binding name="WSBindingConfig"> <security mode="None"> <transport clientCredentialType="None"/> <message establishSecurityContext="false"/> </security> </binding> </wsHttpBinding> </bindings>

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  • STL operator= behavior change with Visual Studio 2010?

    - by augnob
    Hi, I am attempting to compile QtScriptGenerator (gitorious) with Visual Studio 2010 (C++) and have run into a compile error. In searching for a solution, I have seen occasional references to compile breakages introduced since VS2008 due to changes in VS2010's implementation of STL and/or c++0x conformance changes. Any ideas what is happening below, or how I could go about fixing it? If the offending code appeared to be QtScriptGenerator's, I think I would have an easier time fixing it.. but it appears to me that the offending code may be in VS2010's STL implementation and I may be required to create a workaround? PS. I am pretty unfamiliar with templates and STL. I have a background in embedded and console projects where such things have until recently often been avoided to reduce memory consumption and cross-compiler risks. C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xutility(275) : error C2679: binary '=' : no operator found which takes a right-hand operand of type 'rpp::pp_output_iterator<_Container>' (or there is no acceptable conversion) with [ _Container=std::string ] c:\qt\qtscriptgenerator\generator\parser\rpp\pp-iterator.h(75): could be 'rpp::pp_output_iterator<_Container> &rpp::pp_output_iterator<_Container>::operator =(const char &)' with [ _Container=std::string ] while trying to match the argument list '(rpp::pp_output_iterator<_Container>, rpp::pp_output_iterator<_Container>)' with [ _Container=std::string ] C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xutility(2176) : see reference to function template instantiation '_Iter &std::_Rechecked<_OutIt,_OutIt>(_Iter &,_UIter)' being compiled with [ _Iter=rpp::pp_output_iterator<std::string>, _OutIt=rpp::pp_output_iterator<std::string>, _UIter=rpp::pp_output_iterator<std::string> ] c:\qt\qtscriptgenerator\generator\parser\rpp\pp-internal.h(83) : see reference to function template instantiation '_OutIt std::copy<std::_String_iterator<_Elem,_Traits,_Alloc>,_OutputIterator>(_InIt,_InIt,_OutIt)' being compiled with [ _OutIt=rpp::pp_output_iterator<std::string>, _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char>, _OutputIterator=rpp::pp_output_iterator<std::string>, _InIt=std::_String_iterator<char,std::char_traits<char>,std::allocator<char>> ] c:\qt\qtscriptgenerator\generator\parser\rpp\pp-engine-bits.h(500) : see reference to function template instantiation 'void rpp::_PP_internal::output_line<_OutputIterator>(const std::string &,int,_OutputIterator)' being compiled with [ _OutputIterator=rpp::pp_output_iterator<std::string> ] C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xutility(275) : error C2582: 'operator =' function is unavailable in 'rpp::pp_output_iterator<_Container>' with [ _Container=std::string ] Here's some context.. pp-internal.h-- #ifndef PP_INTERNAL_H #define PP_INTERNAL_H #include <algorithm> #include <stdio.h> namespace rpp { namespace _PP_internal { .. 68 template <typename _OutputIterator> 69 void output_line(const std::string &__filename, int __line, _OutputIterator __result) 70 { 71 std::string __msg; 72 73 __msg += "# "; 74 75 char __line_descr[16]; 76 pp_snprintf (__line_descr, 16, "%d", __line); 77 __msg += __line_descr; 78 79 __msg += " \""; 80 81 if (__filename.empty ()) 82 __msg += "<internal>"; 83 else 84 __msg += __filename; 85 86 __msg += "\"\n"; 87 std::copy (__msg.begin (), __msg.end (), __result); 88 }

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  • How do you read from a file into an array of struct?

    - by Thomas.Winsnes
    I'm currently working on an assignment and this have had me stuck for hours. Can someone please help me point out why this isn't working for me? struct book { char title[25]; char author[50]; char subject[20]; int callNumber; char publisher[250]; char publishDate[11]; char location[20]; char status[11]; char type[12]; int circulationPeriod; int costOfBook; }; void PrintBookList(struct book **bookList) { int i; for(i = 0; i < sizeof(bookList); i++) { struct book newBook = *bookList[i]; printf("%s;%s;%s;%d;%s;%s;%s;%s;%s;%d;%d\n",newBook.title, newBook.author, newBook.subject, newBook.callNumber,newBook.publisher, newBook.publishDate, newBook.location, newBook.status, newBook.type,newBook.circulationPeriod, newBook.costOfBook); } } void GetBookList(struct book** bookList) { FILE* file = fopen("book.txt", "r"); struct book newBook[1024]; int i = 0; while(fscanf(file, "%s;%s;%s;%d;%s;%s;%s;%s;%s;%d;%d", &newBook[i].title, &newBook[i].author, &newBook[i].subject, &newBook[i].callNumber,&newBook[i].publisher, &newBook[i].publishDate, &newBook[i].location, &newBook[i].status, &newBook[i].type,&newBook[i].circulationPeriod, &newBook[i].costOfBook) != EOF) { bookList[i] = &newBook[i]; i++; } /*while(fscanf(file, "%s;%s;%s;%d;%s;%s;%s;%s;%s;%d;%d", &bookList[i].title, &bookList[i].author, &bookList[i].subject, &bookList[i].callNumber, &bookList[i].publisher, &bookList[i].publishDate, &bookList[i].location, &bookList[i].status, &bookList[i].type, &bookList[i].circulationPeriod, &bookList[i].costOfBook) != EOF) { i++; }*/ PrintBookList(bookList); fclose(file); } int main() { struct book *bookList[1024]; GetBookList(bookList); } I get no errors or warnings on compile it should print the content of the file, just like it is in the file. Like this: OperatingSystems Internals and Design principles;William.S;IT;741012759;Upper Saddle River;2009;QA7676063;Available;circulation;3;11200 Communication skills handbook;Summers.J;Accounting;771239216;Milton;2010;BF637C451;Available;circulation;3;7900 Business marketing management:B2B;Hutt.D;Management;741912319;Mason;2010;HF5415131;Available;circulation;3;1053 Patient education rehabilitation;Dreeben.O;Education;745121511;Sudbury;2010;CF5671A98;Available;reference;0;6895 Tomorrow's technology and you;Beekman.G;Science;764102174;Upper Saddle River;2009;QA76B41;Out;reserved;1;7825 Property & security: selected essay;Cathy.S;Law;750131231;Rozelle;2010;D4A3C56;Available;reference;0;20075 Introducing communication theory;Richard.W;IT;714789013;McGraw-Hill;2010;Q360W47;Available;circulation;3;12150 Maths for computing and information technology;Giannasi.F;Mathematics;729890537;Longman;Scientific;1995;QA769M35G;Available;reference;0;13500 Labor economics;George.J;Economics;715784761;McGraw-Hill;2010;HD4901B67;Available;circulation;3;7585 Human physiology:from cells to systems;Sherwood.L;Physiology;707558936;Cengage Learning;2010;QP345S32;Out;circulation;3;11135 bobs;thomas;IT;701000000;UC;1006;QA7548;Available;Circulation;7;5050 but when I run it, it outputs this: OperatingSystems;;;0;;;;;;0;0 Internals;;;0;;;;;;0;0 and;;;0;;;;;;0;0 Design;;;0;;;;;;0;0 principles;William.S;IT;741012759;Upper;41012759;Upper;;0;;;;;;0;0 Saddle;;;0;;;;;;0;0 River;2009;QA7676063;Available;circulation;3;11200;lable;circulation;3;11200;;0;;;;;;0;0 Communication;;;0;;;;;;0;0 Thanks in advance, you're a life saver

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  • Serializing WPF DataTemplates and {Binding Expressions} (from PowerShell?)

    - by Jaykul
    Ok, here's the deal: I have code that works in C#, but when I call it from PowerShell, it fails. I can't quite figure it out, but it's something specific to PowerShell. Here's the relevant code calling the library (assuming you've added a reference ahead of time) from C#: public class Test { [STAThread] public static void Main() { Console.WriteLine( PoshWpf.XamlHelper.RoundTripXaml( "<TextBlock Text=\"{Binding FullName}\" xmlns=\"http://schemas.microsoft.com/winfx/2006/xaml/presentation\"/>" ) ); } } Compiled into an executable, that works fine ... but if you call that method from PowerShell, it returns with no {Binding FullName} for the Text! add-type -path .\PoshWpf.dll [PoshWpf.Test]::Main() I've pasted below the entire code for the library, all wrapped up in a PowerShell Add-Type call so you can just compile it by pasting it into PowerShell (you can leave off the first and last lines if you want to paste it into a new console app in Visual Studio. To output (from PowerShell 2) as an executable, just change the -OutputType parameter to ConsoleApplication and the -OutputAssembly to PoshWpf.exe (or something). Thus, you can see that running the SAME CODE from the executable gives you the correct output. But running the two lines as above or manually calling [PoshWpf.XamlHelper]::RoundTripXaml or [PoshWpf.XamlHelper]::ConvertToXaml from PowerShell just doesn't seem to work at all ... HELP?! Add-Type -TypeDefinition @" using System; using System.ComponentModel; using System.Globalization; using System.Linq; using System.Windows; using System.Windows.Data; using System.Windows.Markup; namespace PoshWpf { public class Test { [STAThread] public static void Main() { Console.WriteLine( PoshWpf.XamlHelper.RoundTripXaml( "<TextBlock Text=\"{Binding FullName}\" xmlns=\"http://schemas.microsoft.com/winfx/2006/xaml/presentation\"/>" ) ); } } public class BindingTypeDescriptionProvider : TypeDescriptionProvider { private static readonly TypeDescriptionProvider _DEFAULT_TYPE_PROVIDER = TypeDescriptor.GetProvider(typeof(Binding)); public BindingTypeDescriptionProvider() : base(_DEFAULT_TYPE_PROVIDER) { } public override ICustomTypeDescriptor GetTypeDescriptor(Type objectType, object instance) { ICustomTypeDescriptor defaultDescriptor = base.GetTypeDescriptor(objectType, instance); return instance == null ? defaultDescriptor : new BindingCustomTypeDescriptor(defaultDescriptor); } } public class BindingCustomTypeDescriptor : CustomTypeDescriptor { public BindingCustomTypeDescriptor(ICustomTypeDescriptor parent) : base(parent) { } public override PropertyDescriptorCollection GetProperties(Attribute[] attributes) { PropertyDescriptor pd; var pdc = new PropertyDescriptorCollection(base.GetProperties(attributes).Cast<PropertyDescriptor>().ToArray()); if ((pd = pdc.Find("Source", false)) != null) { pdc.Add(TypeDescriptor.CreateProperty(typeof(Binding), pd, new Attribute[] { new DefaultValueAttribute("null") })); pdc.Remove(pd); } return pdc; } } public class BindingConverter : ExpressionConverter { public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) { return (destinationType == typeof(MarkupExtension)) ? true : false; } public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) { if (destinationType == typeof(MarkupExtension)) { var bindingExpression = value as BindingExpression; if (bindingExpression == null) throw new Exception(); return bindingExpression.ParentBinding; } return base.ConvertTo(context, culture, value, destinationType); } } public static class XamlHelper { static XamlHelper() { // this is absolutely vital: TypeDescriptor.AddProvider(new BindingTypeDescriptionProvider(), typeof(Binding)); TypeDescriptor.AddAttributes(typeof(BindingExpression), new Attribute[] { new TypeConverterAttribute(typeof(BindingConverter)) }); } public static string RoundTripXaml(string xaml) { return XamlWriter.Save(XamlReader.Parse(xaml)); } public static string ConvertToXaml(object wpf) { return XamlWriter.Save(wpf); } } } "@ -language CSharpVersion3 -reference PresentationCore, PresentationFramework, WindowsBase -OutputType Library -OutputAssembly PoshWpf.dll Again, you can get an executable by just altering the last line like so: "@ -language CSharpVersion3 -reference PresentationCore, PresentationFramework, WindowsBase -OutputType ConsoleApplication -OutputAssembly PoshWpf.exe

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  • Why is FubuMVC new()ing up my view model in PartialForEach?

    - by Jon M
    I'm getting started with FubuMVC and I have a simple Customer - Order relationship I'm trying to display using nested partials. My domain objects are as follows: public class Customer { private readonly IList<Order> orders = new List<Order>(); public string Name { get; set; } public IEnumerable<Order> Orders { get { return orders; } } public void AddOrder(Order order) { orders.Add(order); } } public class Order { public string Reference { get; set; } } I have the following controller classes: public class CustomersController { public IndexViewModel Index(IndexInputModel inputModel) { var customer1 = new Customer { Name = "John Smith" }; customer1.AddOrder(new Order { Reference = "ABC123" }); return new IndexViewModel { Customers = new[] { customer1 } }; } } public class IndexInputModel { } public class IndexViewModel { public IEnumerable<Customer> Customers { get; set; } } public class IndexView : FubuPage<IndexViewModel> { } public class CustomerPartial : FubuControl<Customer> { } public class OrderPartial : FubuControl<Order> { } IndexView.aspx: (standard html stuff trimmed) <div> <%= this.PartialForEach(x => x.Customers).Using<CustomerPartial>() %> </div> CustomerPartial.ascx: <%@ Control Language="C#" Inherits="FubuDemo.Controllers.Customers.CustomerPartial" %> <div> Customer Name: <%= this.DisplayFor(x => x.Name) %> <br /> Orders: (<%= Model.Orders.Count() %>) <br /> <%= this.PartialForEach(x => x.Orders) %> </div> OrderPartial.ascx: <%@ Control Language="C#" Inherits="FubuDemo.Controllers.Customers.OrderPartial" %> <div> Order <br /> Ref: <%= this.DisplayFor(x => x.Reference) %> </div> When I view Customers/Index, I see the following: Customers Customer Name: John Smith Orders: (1) It seems that in CustomerPartial.ascx, doing Model.Orders.Count() correctly picks up that 1 order exists. However PartialForEach(x = x.Orders) does not, as nothing is rendered for the order. If I set a breakpoint on the Order constructor, I see that it initially gets called by the Index method on CustomersController, but then it gets called by FubuMVC.Core.Models.StandardModelBinder.Bind, so it is getting re-instantiated by FubuMVC and losing the content of the Orders collection. This isn't quite what I'd expect, I would think that PartialForEach would just pass the domain object directly into the partial. Am I missing the point somewhere? What is the 'correct' way to achieve this kind of result in Fubu?

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  • C++ linked list based tree structure. Sanely copy nodes between lists.

    - by krunk
    edit Clafification: The intention is not to remove the node from the original list. But to create an identical node (data and children wise) to the original and insert that into the new list. In other words, a "move" does not imply a "remove" from the original. endedit The requirements: Each Node in the list must contain a reference to its previous sibling Each Node in the list must contain a reference to its next sibling Each Node may have a list of child nodes Each child Node must have a reference to its parent node Basically what we have is a tree structure of arbitrary depth and length. Something like: -root(NULL) --Node1 ----ChildNode1 ------ChildOfChild --------AnotherChild ----ChildNode2 --Node2 ----ChildNode1 ------ChildOfChild ----ChildNode2 ------ChildOfChild --Node3 ----ChildNode1 ----ChildNode2 Given any individual node, you need to be able to either traverse its siblings. the children, or up the tree to the root node. A Node ends up looking something like this: class Node { Node* previoius; Node* next; Node* child; Node* parent; } I have a container class that stores these and provides STL iterators. It performs your typical linked list accessors. So insertAfter looks like: void insertAfter(Node* after, Node* newNode) { Node* next = after->next; after->next = newNode; newNode->previous = after; next->previous = newNode; newNode->next = next; newNode->parent = after->parent; } That's the setup, now for the question. How would one move a node (and its children etc) to another list without leaving the previous list dangling? For example, if Node* myNode exists in ListOne and I want to append it to listTwo. Using pointers, listOne is left with a hole in its list since the next and previous pointers are changed. One solution is pass by value of the appended Node. So our insertAfter method would become: void insertAfter(Node* after, Node newNode); This seems like an awkward syntax. Another option is doing the copying internally, so you'd have: void insertAfter(Node* after, const Node* newNode) { Node *new_node = new Node(*newNode); Node* next = after->next; after->next = new_node; new_node->previous = after; next->previous = new_node; new_node->next = next; new_node->parent = after->parent; } Finally, you might create a moveNode method for moving and prevent raw insertion or appending of a node that already has been assigned siblings and parents. // default pointer value is 0 in constructor and a operator bool(..) // is defined for the Node bool isInList(const Node* node) const { return (node->previous || node->next || node->parent); } // then in insertAfter and friends if(isInList(newNode) // throw some error and bail I thought I'd toss this out there and see what folks came up with.

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  • not able to show the file from the array...

    - by sjl
    Hi, i'm trying to do an image gallery. i was not able to display the thumbnails stored in the array. instead it keep showing the same thumbnails. anyone can help? very much appreciated.. // Arrays that store the filenames of the text, images and thumbnails var thumbnails:Array = [ "images/image1_thumb.jpg", "images/image2_thumb.jpg", "images/image3_thumb.jpg", "images/image4_thumb.jpg", "images/image5_thumb.jpg", "images/image6_thumb.jpg", "images/image7_thumb.jpg" ]; var images:Array = [ "images/image1.jpg", "images/image2.jpg", "images/image3.jpg", "images/image4.jpg", "images/image5.jpg", "images/image6.jpg", "images/image7.jpg" ]; var textFiles:Array = [ "text/picture1.txt", "text/picture2.txt", "text/picture3.txt", "text/picture4.txt", "text/picture5.txt", "text/picture6.txt", "text/picture7.txt" ]; // NOTE: thumbnail images are 60 x 43 pixels in size // loop through the array and create the thumbnails and position them vertically for (var i:int = 0; i <7; i++) { // create an instance of MyUIThumbnail var thumbs:MyUIThumbnail = new MyUIThumbnail(); // position the thumbnails on the left vertically thumbs.y = 43 * i;/*** FILL IN THE BLANK HERE ***/ // store the corresponding full size image name in the thumbnail // use the "images" array thumbs.image = "images/image1.jpg"; thumbs.image = "images/image2.jpg"; thumbs.image = "images/image3.jpg"; thumbs.image = "images/image4.jpg"; thumbs.image = "images/image5.jpg"; thumbs.image = "images/image6.jpg"; thumbs.image = "images/image7.jpg"; // store the corresponding text file name in the thumbnail // use the "textFiles" array thumbs.textFile = "text/picture1.txt"; thumbs.textFile = "text/picture2.txt"; thumbs.textFile = "text/picture3.txt"; thumbs.textFile = "text/picture4.txt"; thumbs.textFile = "text/picture5.txt"; thumbs.textFile = "text/picture6.txt"; thumbs.textFile = "text/picture7.txt"; thumbs.imageFullSize = full_image_mc ; // store the reference to the textfield in the thumbnail thumbs.infoText = info; // load and display the thumbnails // use the "thumbnails" array thumbs.loadThumbnail("images/image1_thumb.jpg"); thumbs.loadThumbnail("images/image2_thumb.jpg"); thumbs.loadThumbnail("images/image3_thumb.jpg"); thumbs.loadThumbnail("images/image4_thumb.jpg"); thumbs.loadThumbnail("images/image5_thumb.jpg"); thumbs.loadThumbnail("images/image6_thumb.jpg"); thumbs.loadThumbnail("images/image7_thumb.jpg"); addChild(thumbs); } below is my thumbanail. as package{ import fl.containers.; import flash.events.; import flash.text.; import flash.net.; import flash.display.*; public class MyUIThumbnail extends MovieClip { public var image:String = ""; public var textFile:String = ""; var loader:UILoader = new UILoader(); public var imageFullSize:MyFullSizeImage; // reference to loader to show the full size image public var infoText:TextField; // reference to textfield that displays image infoText var txtLoader:URLLoader = new URLLoader(); // loader to load the text file public function MyUIThumbnail() { buttonMode = true; addChild(loader); this.addEventListener(MouseEvent.CLICK, myClick); txtLoader.addEventListener(Event.COMPLETE, displayText); loader.addEventListener(Event.COMPLETE, thumbnailLoaded); } public function loadThumbnail(filename:String):void { loader.source = filename; preloader.trackLoading(loader); } function myClick(e:MouseEvent):void { // load and display the full size image imageFullSize.loadImage("my_full_mc"); // load and display the text textLoad("info"); } function textLoad(file:String) { // load the text description from the text file loader.load(new URLRequest(textFile)); } function displayText(e:Event) { //display the text when loading is completed addChild(infoText); } function thumbnailLoaded(e:Event) { loader.width = 60; loader.height = 43; } } }

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  • The dynamic Type in C# Simplifies COM Member Access from Visual FoxPro

    - by Rick Strahl
    I’ve written quite a bit about Visual FoxPro interoperating with .NET in the past both for ASP.NET interacting with Visual FoxPro COM objects as well as Visual FoxPro calling into .NET code via COM Interop. COM Interop with Visual FoxPro has a number of problems but one of them at least got a lot easier with the introduction of dynamic type support in .NET. One of the biggest problems with COM interop has been that it’s been really difficult to pass dynamic objects from FoxPro to .NET and get them properly typed. The only way that any strong typing can occur in .NET for FoxPro components is via COM type library exports of Visual FoxPro components. Due to limitations in Visual FoxPro’s type library support as well as the dynamic nature of the Visual FoxPro language where few things are or can be described in the form of a COM type library, a lot of useful interaction between FoxPro and .NET required the use of messy Reflection code in .NET. Reflection is .NET’s base interface to runtime type discovery and dynamic execution of code without requiring strong typing. In FoxPro terms it’s similar to EVALUATE() functionality albeit with a much more complex API and corresponiding syntax. The Reflection APIs are fairly powerful, but they are rather awkward to use and require a lot of code. Even with the creation of wrapper utility classes for common EVAL() style Reflection functionality dynamically access COM objects passed to .NET often is pretty tedious and ugly. Let’s look at a simple example. In the following code I use some FoxPro code to dynamically create an object in code and then pass this object to .NET. An alternative to this might also be to create a new object on the fly by using SCATTER NAME on a database record. How the object is created is inconsequential, other than the fact that it’s not defined as a COM object – it’s a pure FoxPro object that is passed to .NET. Here’s the code: *** Create .NET COM InstanceloNet = CREATEOBJECT('DotNetCom.DotNetComPublisher') *** Create a Customer Object Instance (factory method) loCustomer = GetCustomer() loCustomer.Name = "Rick Strahl" loCustomer.Company = "West Wind Technologies" loCustomer.creditLimit = 9999999999.99 loCustomer.Address.StreetAddress = "32 Kaiea Place" loCustomer.Address.Phone = "808 579-8342" loCustomer.Address.Email = "[email protected]" *** Pass Fox Object and echo back values ? loNet.PassRecordObject(loObject) RETURN FUNCTION GetCustomer LOCAL loCustomer, loAddress loCustomer = CREATEOBJECT("EMPTY") ADDPROPERTY(loCustomer,"Name","") ADDPROPERTY(loCustomer,"Company","") ADDPROPERTY(loCUstomer,"CreditLimit",0.00) ADDPROPERTY(loCustomer,"Entered",DATETIME()) loAddress = CREATEOBJECT("Empty") ADDPROPERTY(loAddress,"StreetAddress","") ADDPROPERTY(loAddress,"Phone","") ADDPROPERTY(loAddress,"Email","") ADDPROPERTY(loCustomer,"Address",loAddress) RETURN loCustomer ENDFUNC Now prior to .NET 4.0 you’d have to access this object passed to .NET via Reflection and the method code to do this would looks something like this in the .NET component: public string PassRecordObject(object FoxObject) { // *** using raw Reflection string Company = (string) FoxObject.GetType().InvokeMember( "Company", BindingFlags.GetProperty,null, FoxObject,null); // using the easier ComUtils wrappers string Name = (string) ComUtils.GetProperty(FoxObject,"Name"); // Getting Address object – then getting child properties object Address = ComUtils.GetProperty(FoxObject,"Address");    string Street = (string) ComUtils.GetProperty(FoxObject,"StreetAddress"); // using ComUtils 'Ex' functions you can use . Syntax     string StreetAddress = (string) ComUtils.GetPropertyEx(FoxObject,"AddressStreetAddress"); return Name + Environment.NewLine + Company + Environment.NewLine + StreetAddress + Environment.NewLine + " FOX"; } Note that the FoxObject is passed in as type object which has no specific type. Since the object doesn’t exist in .NET as a type signature the object is passed without any specific type information as plain non-descript object. To retrieve a property the Reflection APIs like Type.InvokeMember or Type.GetProperty().GetValue() etc. need to be used. I made this code a little simpler by using the Reflection Wrappers I mentioned earlier but even with those ComUtils calls the code is pretty ugly requiring passing the objects for each call and casting each element. Using .NET 4.0 Dynamic Typing makes this Code a lot cleaner Enter .NET 4.0 and the dynamic type. Replacing the input parameter to the .NET method from type object to dynamic makes the code to access the FoxPro component inside of .NET much more natural: public string PassRecordObjectDynamic(dynamic FoxObject) { // *** using raw Reflection string Company = FoxObject.Company; // *** using the easier ComUtils class string Name = FoxObject.Name; // *** using ComUtils 'ex' functions to use . Syntax string Address = FoxObject.Address.StreetAddress; return Name + Environment.NewLine + Company + Environment.NewLine + Address + Environment.NewLine + " FOX"; } As you can see the parameter is of type dynamic which as the name implies performs Reflection lookups and evaluation on the fly so all the Reflection code in the last example goes away. The code can use regular object ‘.’ syntax to reference each of the members of the object. You can access properties and call methods this way using natural object language. Also note that all the type casts that were required in the Reflection code go away – dynamic types like var can infer the type to cast to based on the target assignment. As long as the type can be inferred by the compiler at compile time (ie. the left side of the expression is strongly typed) no explicit casts are required. Note that although you get to use plain object syntax in the code above you don’t get Intellisense in Visual Studio because the type is dynamic and thus has no hard type definition in .NET . The above example calls a .NET Component from VFP, but it also works the other way around. Another frequent scenario is an .NET code calling into a FoxPro COM object that returns a dynamic result. Assume you have a FoxPro COM object returns a FoxPro Cursor Record as an object: DEFINE CLASS FoxData AS SESSION OlePublic cAppStartPath = "" FUNCTION INIT THIS.cAppStartPath = ADDBS( JustPath(Application.ServerName) ) SET PATH TO ( THIS.cAppStartpath ) ENDFUNC FUNCTION GetRecord(lnPk) LOCAL loCustomer SELECT * FROM tt_Cust WHERE pk = lnPk ; INTO CURSOR TCustomer IF _TALLY < 1 RETURN NULL ENDIF SCATTER NAME loCustomer MEMO RETURN loCustomer ENDFUNC ENDDEFINE If you call this from a .NET application you can now retrieve this data via COM Interop and cast the result as dynamic to simplify the data access of the dynamic FoxPro type that was created on the fly: int pk = 0; int.TryParse(Request.QueryString["id"],out pk); // Create Fox COM Object with Com Callable Wrapper FoxData foxData = new FoxData(); dynamic foxRecord = foxData.GetRecord(pk); string company = foxRecord.Company; DateTime entered = foxRecord.Entered; This code looks simple and natural as it should be – heck you could write code like this in days long gone by in scripting languages like ASP classic for example. Compared to the Reflection code that previously was necessary to run similar code this is much easier to write, understand and maintain. For COM interop and Visual FoxPro operation dynamic type support in .NET 4.0 is a huge improvement and certainly makes it much easier to deal with FoxPro code that calls into .NET. Regardless of whether you’re using COM for calling Visual FoxPro objects from .NET (ASP.NET calling a COM component and getting a dynamic result returned) or whether FoxPro code is calling into a .NET COM component from a FoxPro desktop application. At one point or another FoxPro likely ends up passing complex dynamic data to .NET and for this the dynamic typing makes coding much cleaner and more readable without having to create custom Reflection wrappers. As a bonus the dynamic runtime that underlies the dynamic type is fairly efficient in terms of making Reflection calls especially if members are repeatedly accessed. © Rick Strahl, West Wind Technologies, 2005-2010Posted in COM  FoxPro  .NET  CSharp  

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  • Dynamic Type to do away with Reflection

    - by Rick Strahl
    The dynamic type in C# 4.0 is a welcome addition to the language. One thing I’ve been doing a lot with it is to remove explicit Reflection code that’s often necessary when you ‘dynamically’ need to walk and object hierarchy. In the past I’ve had a number of ReflectionUtils that used string based expressions to walk an object hierarchy. With the introduction of dynamic much of the ReflectionUtils code can be removed for cleaner code that runs considerably faster to boot. The old Way - Reflection Here’s a really contrived example, but assume for a second, you’d want to dynamically retrieve a Page.Request.Url.AbsoluteUrl based on a Page instance in an ASP.NET Web Page request. The strongly typed version looks like this: string path = Page.Request.Url.AbsolutePath; Now assume for a second that Page wasn’t available as a strongly typed instance and all you had was an object reference to start with and you couldn’t cast it (right I said this was contrived :-)) If you’re using raw Reflection code to retrieve this you’d end up writing 3 sets of Reflection calls using GetValue(). Here’s some internal code I use to retrieve Property values as part of ReflectionUtils: /// <summary> /// Retrieve a property value from an object dynamically. This is a simple version /// that uses Reflection calls directly. It doesn't support indexers. /// </summary> /// <param name="instance">Object to make the call on</param> /// <param name="property">Property to retrieve</param> /// <returns>Object - cast to proper type</returns> public static object GetProperty(object instance, string property) { return instance.GetType().GetProperty(property, ReflectionUtils.MemberAccess).GetValue(instance, null); } If you want more control over properties and support both fields and properties as well as array indexers a little more work is required: /// <summary> /// Parses Properties and Fields including Array and Collection references. /// Used internally for the 'Ex' Reflection methods. /// </summary> /// <param name="Parent"></param> /// <param name="Property"></param> /// <returns></returns> private static object GetPropertyInternal(object Parent, string Property) { if (Property == "this" || Property == "me") return Parent; object result = null; string pureProperty = Property; string indexes = null; bool isArrayOrCollection = false; // Deal with Array Property if (Property.IndexOf("[") > -1) { pureProperty = Property.Substring(0, Property.IndexOf("[")); indexes = Property.Substring(Property.IndexOf("[")); isArrayOrCollection = true; } // Get the member MemberInfo member = Parent.GetType().GetMember(pureProperty, ReflectionUtils.MemberAccess)[0]; if (member.MemberType == MemberTypes.Property) result = ((PropertyInfo)member).GetValue(Parent, null); else result = ((FieldInfo)member).GetValue(Parent); if (isArrayOrCollection) { indexes = indexes.Replace("[", string.Empty).Replace("]", string.Empty); if (result is Array) { int Index = -1; int.TryParse(indexes, out Index); result = CallMethod(result, "GetValue", Index); } else if (result is ICollection) { if (indexes.StartsWith("\"")) { // String Index indexes = indexes.Trim('\"'); result = CallMethod(result, "get_Item", indexes); } else { // assume numeric index int index = -1; int.TryParse(indexes, out index); result = CallMethod(result, "get_Item", index); } } } return result; } /// <summary> /// Returns a property or field value using a base object and sub members including . syntax. /// For example, you can access: oCustomer.oData.Company with (this,"oCustomer.oData.Company") /// This method also supports indexers in the Property value such as: /// Customer.DataSet.Tables["Customers"].Rows[0] /// </summary> /// <param name="Parent">Parent object to 'start' parsing from. Typically this will be the Page.</param> /// <param name="Property">The property to retrieve. Example: 'Customer.Entity.Company'</param> /// <returns></returns> public static object GetPropertyEx(object Parent, string Property) { Type type = Parent.GetType(); int at = Property.IndexOf("."); if (at < 0) { // Complex parse of the property return GetPropertyInternal(Parent, Property); } // Walk the . syntax - split into current object (Main) and further parsed objects (Subs) string main = Property.Substring(0, at); string subs = Property.Substring(at + 1); // Retrieve the next . section of the property object sub = GetPropertyInternal(Parent, main); // Now go parse the left over sections return GetPropertyEx(sub, subs); } As you can see there’s a fair bit of code involved into retrieving a property or field value reliably especially if you want to support array indexer syntax. This method is then used by a variety of routines to retrieve individual properties including one called GetPropertyEx() which can walk the dot syntax hierarchy easily. Anyway with ReflectionUtils I can  retrieve Page.Request.Url.AbsolutePath using code like this: string url = ReflectionUtils.GetPropertyEx(Page, "Request.Url.AbsolutePath") as string; This works fine, but is bulky to write and of course requires that I use my custom routines. It’s also quite slow as the code in GetPropertyEx does all sorts of string parsing to figure out which members to walk in the hierarchy. Enter dynamic – way easier! .NET 4.0’s dynamic type makes the above really easy. The following code is all that it takes: object objPage = Page; // force to object for contrivance :) dynamic page = objPage; // convert to dynamic from untyped object string scriptUrl = page.Request.Url.AbsolutePath; The dynamic type assignment in the first two lines turns the strongly typed Page object into a dynamic. The first assignment is just part of the contrived example to force the strongly typed Page reference into an untyped value to demonstrate the dynamic member access. The next line then just creates the dynamic type from the Page reference which allows you to access any public properties and methods easily. It also lets you access any child properties as dynamic types so when you look at Intellisense you’ll see something like this when typing Request.: In other words any dynamic value access on an object returns another dynamic object which is what allows the walking of the hierarchy chain. Note also that the result value doesn’t have to be explicitly cast as string in the code above – the compiler is perfectly happy without the cast in this case inferring the target type based on the type being assigned to. The dynamic conversion automatically handles the cast when making the final assignment which is nice making for natural syntnax that looks *exactly* like the fully typed syntax, but is completely dynamic. Note that you can also use indexers in the same natural syntax so the following also works on the dynamic page instance: string scriptUrl = page.Request.ServerVariables["SCRIPT_NAME"]; The dynamic type is going to make a lot of Reflection code go away as it’s simply so much nicer to be able to use natural syntax to write out code that previously required nasty Reflection syntax. Another interesting thing about the dynamic type is that it actually works considerably faster than Reflection. Check out the following methods that check performance: void Reflection() { Stopwatch stop = new Stopwatch(); stop.Start(); for (int i = 0; i < reps; i++) { // string url = ReflectionUtils.GetProperty(Page,"Title") as string;// "Request.Url.AbsolutePath") as string; string url = Page.GetType().GetProperty("Title", ReflectionUtils.MemberAccess).GetValue(Page, null) as string; } stop.Stop(); Response.Write("Reflection: " + stop.ElapsedMilliseconds.ToString()); } void Dynamic() { Stopwatch stop = new Stopwatch(); stop.Start(); dynamic page = Page; for (int i = 0; i < reps; i++) { string url = page.Title; //Request.Url.AbsolutePath; } stop.Stop(); Response.Write("Dynamic: " + stop.ElapsedMilliseconds.ToString()); } The dynamic code runs in 4-5 milliseconds while the Reflection code runs around 200+ milliseconds! There’s a bit of overhead in the first dynamic object call but subsequent calls are blazing fast and performance is actually much better than manual Reflection. Dynamic is definitely a huge win-win situation when you need dynamic access to objects at runtime.© Rick Strahl, West Wind Technologies, 2005-2010Posted in .NET  CSharp  

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