Search Results

Search found 19480 results on 780 pages for 'do your own homework'.

Page 633/780 | < Previous Page | 629 630 631 632 633 634 635 636 637 638 639 640  | Next Page >

• How do I write a J2EE/EJB Singleton?

  - by Bears will eat you

  A day ago my application was one EAR, containing one WAR, one EJB JAR, and a couple of utility JAR files. I had a POJO singleton class in one of those utility files, it worked, and all was well with the world: EAR |--- WAR |--- EJB JAR |--- Util 1 JAR |--- Util 2 JAR |--- etc. Then I created a second WAR and found out (the hard way) that each WAR has its own ClassLoader, so each WAR sees a different singleton, and things break down from there. This is not so good. EAR |--- WAR 1 |--- WAR 2 |--- EJB JAR |--- Util 1 JAR |--- Util 2 JAR |--- etc. So, I'm looking for a way to create a Java singleton object that will work across WARs (across ClassLoaders?). The @Singleton EJB annotation seemed pretty promising until I found that JBoss 5.1 doesn't seem to support that annotation (which was added as part of EJB 3.1). Did I miss something - can I use @Singleton with JBoss 5.1? Upgrading to JBoss AS 6 is not an option right now. Alternately, I'd be just as happy to not have to use EJB to implement my singleton. What else can I do to solve this problem? Basically, I need a semi-application-wide* hook into a whole bunch of other objects, like various cached data, and app config info. As a last resort, I've already considered merging my two WARs into one, but that would be pretty hellish. *Meaning: available basically anywhere above a certain layer; for now, mostly in my WARs - the View and Controller (in a loose sense).

  Read the article

• inserting selected page from one word document in another word document with c#

  - by daemonkid

  I have a requirement to move selected pages from word DocumentA into another word DocumentB. So in the end DocumentB should have its own contents plus selected pages from DocumentA inserted at selected pages in DocumentB. The page number in DocumentB I will set thru properties. This is the code I am using to just append contents of DocumentA to DocumentB. object missing = System.Reflection.Missing.Value; Word._Application wordApp = new Word.Application(); Word._Document aDoc = new Word.Document(); try { wordApp.Visible = false; object readOnly = false; object isVisible = false; aDoc = wordApp.Documents.Open(ref fPath1, ref missing, ref readOnly, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref isVisible, ref missing, ref missing, ref missing, ref missing); Word.Selection selection = wordApp.Selection; selection.InsertFile(fPath2, ref missing, ref missing, ref missing, ref missing); aDoc.Save(); wordApp.Quit(ref missing, ref missing, ref missing); } catch(Exception ex) { throw new Exception(ex.Message); } finally { wordApp = null; aDoc = null; } However, I keep getting this exception 'object reference not set to instance of object' at the line 'selection.InsertFile...' What is going wrong here? And how do I insert contents of page 2 from DocumentA into page 3 of DocumentB? Thanks for your time.

  Read the article

• Git force complete sync to master

  - by Jesse

  My workplace uses Subversion for source control so I have been playing around with git-svn for the advantages of my own branches, commit as often as I want without touching the main repo, etc. Since my git svn checkout is local, I have cloned it to a network share as well to act as a backup. My thinking is that if my desktop takes a dump I will at least have the repo on the network share to get changes that I have not had a chance to dcommit yet. My workflow is to work from the desktop, make changes, commit, etc. At the end of the day I want to update the repo on the network share with all of my current changes. I had setup the repo on the network share using git clone repo_on_my_desktop and then updating the repo on the network share with git pull origin master. The problem that I am running into is when I used do a git rebase to squish multiple commits prior to dcommitting to the main svn repository. When I do this, I get merge conflicts on the repo on the network share when I try to backup at night. Is there a way to simply sync entirely with the repository on my desktop without doing a new git clone each night?

  Read the article

• Is It Incorrect to Make Domain Objects Aware of The Data Access Layer?

  - by Noah Goodrich

  I am currently working on rewriting an application to use Data Mappers that completely abstract the database from the Domain layer. However, I am now wondering which is the better approach to handling relationships between Domain objects: Call the necessary find() method from the related data mapper directly within the domain object Write the relationship logic into the native data mapper (which is what the examples tend to do in PoEAA) and then call the native data mapper function within the domain object. Either it seems to me that in order to preserve the 'Fat Model, Skinny Controller' mantra, the domain objects have to be aware of the data mappers (whether it be their own or that they have access to the other mappers in the system). Additionally it seems that Option 2 unnecessarily complicates the data access layer as it creates table access logic across multiple data mappers instead of confining it to a single data mapper. So, is it incorrect to make the domain objects aware of the related data mappers and to call data mapper functions directly from the domain objects? Update: These are the only two solutions that I can envision to handle the issue of relations between domain objects. Any example showing a better method would be welcome.

  Read the article

• Directly call distutils' or setuptools' setup() function with command name/options, without parsing

  - by Ryan B. Lynch

  I'd like to call Python's distutils' or setuptools' setup() function in a slightly unconventional way, but I'm not sure whether distutils is meant for this kind of usage. As an example, let's say I currently have a 'setup.py' file, which looks like this (lifted verbatim from the distutils docs--the setuptools usage is almost identical): from distutils.core import setup setup(name='Distutils', version='1.0', description='Python Distribution Utilities', author='Greg Ward', author_email='[email protected]', url='http://www.python.org/sigs/distutils-sig/', packages=['distutils', 'distutils.command'], ) Normally, to build just the .spec file for an RPM of this module, I could run python setup.py bdist_rpm --spec-only, which parses the command line and calls the 'bdist_rpm' code to handle the RPM-specific stuff. The .spec file ends up in './dist'. How can I change my setup() invocation so that it runs the 'bdist_rpm' command with the '--spec-only' option, WITHOUT parsing command-line parameters? Can I pass the command name and options as parameters to setup()? Or can I manually construct a command line, and pass that as a parameter, instead? NOTE: I already know that I could call the script in a separate process, with an actual command line, using os.system() or the subprocess module or something similar. I'm trying to avoid using any kind of external command invocations. I'm looking specifically for a solution that runs setup() in the current interpreter. For background, I'm converting some release-management shell scripts into a single Python program. One of the tasks is running 'setup.py' to generate a .spec file for further pre-release testing. Running 'setup.py' as an external command, with its own command line options, seems like an awkward method, and it complicates the rest of the program. I feel like there may be a more Pythonic way.

  Read the article

• unistd.h related problem when compiling bison & flex program under vc++

  - by Eric

  I'm using bison & flex (downloaded via cygwin) with vc++. When I compile the program I got an error: ...: fatal error C1083: Cannot open include file: 'unistd.h': No such file or directory The corresponding code in the flex-generated file is: #ifndef YY_NO_UNISTD_H /* Special case for "unistd.h", since it is non-ANSI. We include it way * down here because we want the user's section 1 to have been scanned first. * The user has a chance to override it with an option. */ /* %if-c-only */ #include <unistd.h> /* %endif */ /* %if-c++-only */ /* %endif */ #endif If I define YY_NO_UNISTD_H in the flex file(.l) this error will disappear, but I get several other errors: ...: error C2447: '{' : missing function header (old-style formal list?) ...: warning C4018: '<' : signed/unsigned mismatch ...: error C3861: 'isatty': identifier not found How can I fix this problem? All these errors occur in the flex-generated scanner. I know it's because unistd.h doesn't exist in windows. Do I have to write my own unistd.h? If so how to write it in order to eliminate those errors?

  Read the article

• Preferred way of application initialization

  - by lisak

  Do you guys have your own little framework for project startups ? I mean, every time one needs to do the same things at the beginning: Context initialization - ideally after arguments are processed. Sometimes without interactive user input, sometimes with input reader. Sometimes we need to load properties, sometimes not. Then we need to get a class out of context and run its method. Programming....programming until writing shell script to place everything on classpath. It's true that it differs according to the actual needs. But it seems to me, that I'm doing always almost the same, again and again from the scratch. Sometimes I realize that I'm postponing my work just because I don't want to do these annoying startups. It would be great if there was some kind of universal Main class doing reflection to specified bean, context initialization, argument parsing, interactive user input reading and have the programmer do the important things...All setup might be done via spring configuration. I think I'll have to do it by myself. I'd appreciate your ideas

  Read the article

• Allowing Google to bypass CAPTCHA verification - sensible or not?

  - by edanfalls

  My web site has a database lookup; filling out a CAPTCHA gives you 5 minutes of lookup time. There is also some custom code to detect any automated scripts. I do this as I don't want someone data mining my site. The problem is that Google does not see the lookup results when it crawls my site. If someone is searching for a string that is present in the result of a lookup, I would like them to find this page by Googling it. The obvious solution to me is to use the PHP variable $_SERVER['HTTP_USER_AGENT'] to bypass the CAPTCHA and custom security code for the Google bots. My question is whether this is sensible or not. People could then use Google's cache to view the lookup results without having to fill out the CAPTCHA, but would Google's own script detection methods prevent them from data mining these pages? Or would there be some way for people to make $_SERVER['HTTP_USER_AGENT'] appear as Google to bypass the security measures? Thanks in advance.

  Read the article

• django class with an array of "parent" foreignkeys issue

  - by user298032

  Let's say I have a class called Fruit with child classes of the different kinds of Fruit with their own specific attributes, and I want to collect them in a FruitBasket: class Fruit(models.Model):     type = models.CharField(max_length=120,default='banana',choices=FRUIT_TYPES)     ... class Banana(Fruit):     """banana (fruit type)"""     length = models.IntegerField(blank=True, null=True)     ... class Orange(Fruit):     """orange (fruit type)"""     diameter = models.IntegerField(blank=True, null=True)     ... class FruitBasket(models.Model):     fruits = models.ManyToManyField(Fruit)     ... The problem I seem to be having is when I retrieve and inspect the Fruits in a FruitBasket, I only retrieve the Fruit base class and can't get at the Fruit child class attributes. I think I understand what is happening--when the array is retrieved from the database, the only fields that are retrieved are the Fruit base class fields. But is there some way to get the child class attributes as well without multiple expensive database transactions? (For example, I could get the array, then retrieve the child Fruit classes by the id of each array element). thanks in advance, Chuck

  Read the article

• firefox lead dot in cookie issue

  - by Jon

  Hi all, We are having an annoying issue with Firefox and cookies. We have the following domains: sub1.mydomain.com sub2.mydomain.com sub3.mydomain.com otherdomain.com We have converting our framework to be multilingual and providing a drop down to change the language at any point during site. The code base is shared across all the domains above. We can not set a cookie across all "mydomain.com" sites, they have to be on each of the sub domains. To get this to work we set a JavaScript cookie when the users chooses a new language. When the page posts back to the server the code picks this up and sets the users preferences to that new language code, (this is all C# and ASP.NET). We have to set the host to be "subX.mydomain.com" and the path to be "/" in the cookie so that it is just for the subdomain and all parts of that domain. This works great on all browsers apart from FireFox. It seems that firefox will pre append a DOT to the beginning of domain so ".subX.mydomain.com". When the code posts back with FireFox the cookie is always null. Has anyone had this situation, (I imagine it is not al that uncommon). I have read a lot of people saying, remove the domain from the cookie, but that can not work for us as we have multiple subdomains that need their own cookie values. Thanks

  Read the article

• C# POCO T4 template, generate interfaces?

  - by Jonna

  Does anyone know of any tweaked version of POCO T4 template that generates interfaces along with classes? i.e. if I have Movie and Actor entities in .edmx file, I need to get the following classes and interfaces. interface IMovie { string MovieName { get; set; } ICollection<IActor> Actors { get; set; } //instead of ICollection<Actor> } class Movie : IMovie { string MovieName { get; set; } ICollection<IActor> Actors { get; set; } //instead of ICollection<Actor> } interface IActor { string ActorName { get; set; } } class Actor { string ActorName { get; set; } } Also, just in case I write my own entities, does POCO proxies(I need them for lazy loading) work with the interface declarations as shown above?

  Read the article

• How to Capture a live stream from Windows Media Server 2008

  - by Hummad Hassan

  I want to capture the live stream from windows media server to filesystem on my pc I have tried with my own media server with the following code. but when i have checked the out put file i have found this in it. FileStream fs = null; try { HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://mywmsserver/test"); CookieContainer ci = new CookieContainer(1000); req.Timeout = 60000; req.Method = "Get"; req.KeepAlive = true; req.MaximumAutomaticRedirections = 99; req.UseDefaultCredentials = true; req.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3"; req.ReadWriteTimeout = 90000000; req.CookieContainer = ci; //req.MediaType = "video/x-ms-asf"; req.AllowWriteStreamBuffering = true; HttpWebResponse resp = (HttpWebResponse)req.GetResponse(); Stream resps = resp.GetResponseStream(); fs = new FileStream("d:\\dump.wmv", FileMode.Create, FileAccess.ReadWrite); byte[] buffer = new byte[1024]; int bytesRead = 0; while ((bytesRead = resps.Read(buffer, 0, buffer.Length)) > 0) { fs.Write(buffer, 0, bytesRead); } } catch (Exception ex) { } finally { if (fs != null) fs.Close(); }

  Read the article

• Trouble with __VA_ARGS__

  - by Noah Roberts

  C++ preprocessor __VA_ARGS__ number of arguments The accepted answer there doesn't work for me. I've tried with MSVC++ 10 and g++ 3.4.5. I also crunched the example down into something smaller and started trying to get some information printed out to me in the error: template < typename T > struct print; #include <boost/mpl/vector_c.hpp> #define RSEQ_N 10,9,8,7,6,5,4,3,2,1,0 #define ARG_N(_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,N,...) N #define ARG_N_(...) ARG_N(__VA_ARGS__) #define XXX 5,RSEQ_N #include <iostream> int main() { print< boost::mpl::vector_c<int, ARG_N_( XXX ) > > g; // ARG_N doesn't work either. } It appears to me that the argument for ARG_N ends up being 'XXX' instead of 5,RSEQ_N and much less 5,10,...,0. The error output of g++ more specifically says that only one argument is supplied. Having trouble believing that the answer would be proposed and then accepted when it totally fails to work, so what am I doing wrong? Why is XXX being interpreted as the argument and not being expanded? In my own messing around everything works fine until I try to pass off VA_ARGS to a macro containing some names followed by ... like so: #define WTF(X,Y,...) X , Y , __VA_ARGS__ #define WOT(...) WTF(__VA_ARGS__) WOT(52,2,5,2,2) I've tried both with and without () in the various macros that take no input.

  Read the article

• Generate an ID via COM interop

  - by Erik van Brakel

  At the moment, we've got an unmaintanable ball of code which offers an interface to a third party application. The third party application has a COM assembly which MUST be used to create new entries. This process involves two steps: generate a new object (basically an ID), and update that object with new field values. Because COM interop is so slow, we only use that to generate the ID (and related objects) in the database. The actual update is done using a regular SQL query. What I am trying to figure out if it's possible to use NHibernate to do some of the heavy lifting for us, without bypassing the COM assembly. Here's the code for saving something to the database as I envision it: using(var s = sessionFactory.OpenSession()) using(var t = s.BeginTransaction()) { MyEntity entity = new MyEntity(); s.Save(entity); t.Commit(); } Regular NH code I'd say. Now, this is where it gets tricky. I think I have to supply my own implementation of NHibernate.Id.IIdentifierGenerator which calls the COM assembly in the Generate method. That's not a problem. What IS a problem is that the COM assembly requires initialisation, which does take a bit of time. It also doesn't like multiple instances in the same process, for some reason. What I would like to know is if there's a way to properly access an external service in the generator code. I'm free to use any technique I want, so if it involves something like an IoC container that's no problem. The thing I am looking for is where exactly to hook-up my code so I can access the things I need in my generator, without having to resort to using singletons or other nasty stuff.

  Read the article

• Can I use a specific model from within a behavior in CakePHP?

  - by Paul Willy

  I'm trying to write a behavior that will give my models access to a simple workflow engine I've devised. The workflow engine itself works as a CakePHP model, with workflow data stored in the database just as any other model data is stored. Basically what I want to do is have the behavior use the workflow model whenever an action is called on the base model. For example, if the edit() action is executed for Posts, then the Post (with the behavior attached) will trigger the workflow behavior with its own model name, action, and id as arguments (e.g. [Post, edit, 1]). Then the behavior will invoke the functionality of the Workflow model, which has a record for what to do when edit is run on Posts (e.g. send e-mail to users who are subscribed to that post) and will carry that out. My question is, what is the proper way to invoke model/controller methods from within the behavior? The model to be used from within the behavior will always be Workflow, but the behavior should be usable from basically any model (aside from Workflow itself). I know I could run SQL queries directly from the behavior, but of course this is not the Cake way :-) Or, am I going about this in the wrong way? I want to store a certain amount of logic in the database so that it is easily configurable by different users, and not have endless configuration checks within the model/controller logic itself so that workflow steps can be easily added/changed/removed in the future.

  Read the article

• are there java based auto-updating tools other than WebStart & Eclipse P2?

  - by DaddyB

  Hi, I am working on a java based application and we are looking to ease our deployment of updates. Up until now, we've always simply sent out new install packs & had the sysadmin's on our customer sites roll out the upgrades - painful for a large number of users. what I'd like to do is something similar to java webstart (or eclipse p2) - when the application starts, it checks for updates in a specified location and then downloads the updates prior to starting. But here's my problem - I want more control over what's done outside of the scope of plugins & jar files. For example: I'd like to be able to upate my JVM (we ship a modified version with additional security features). I need to install DLL's - possibly local to the jar files, sometimes to windows Occasiontally run MSI's to install windows components (e.g. printer drivers). I need to modify config files & the registry. I have found a few applications that support this (such as AppLifeUpdate at http://www.kineticjump.com/) but they tend to be .NET focused and it seems a bit perverse to introduce a .NET dependancy on a java application ;) I know I could write my own here, but if there is already a 3rd party library out there that supports this kind of facility, then it would make my life a lot easier. So, has anyone else had a similar problem & knows of some products I could look at? Thanks, Brian.

  Read the article

• Ignoring build number when referencing dll

  - by brickner

  I have one solution with a .NET 4.0 project (C#) that produces a delayed signed dll, that I dotfuscate and sign. EDIT: This is how I version the dll: [assembly: AssemblyVersion("0.7.0.*")] [assembly: AssemblyFileVersion("0.7.0.0")] I have another solution with a .NET 4.0 project (C++/CLI) that references the signed dll and produces a signed dll (actually, delayed signed and signed in a post build because of a flaw in the C++ build system). The problem is that the reference to the dll contains a specific version number, which includes even the build number (I want to have a build number). Every time I build the referenced dll, I have to change the project settings file (.vcxproj) so it reference the new version dll. Since I work with source control, this is very inconvenient (different computers might have different build numbers since each computer build its own referenced dll - the referenced dll is not in the source control). If I don't change the reference, I get a warning: warning MSB3245: Could not resolve this reference. Could not locate the assembly... And many errors like this: error C3083: 'Foo': the symbol to the left of a '::' must be a type These are resolved once I change the reference. How do I make the reference ignore the build number or even the entire version number?

  Read the article

• Can a stateless WCF service benefit from built-in database connection pooling?

  - by vladimir

  I understand that a typical .NET application that accesses a(n SQL Server) database doesn't have to do anything in particular in order to benefit from the connection pooling. Even if an application repeatedly opens and closes database connections, they do get pooled by the framework (assuming that things such as credentials do not change from call to call). My usage scenario seems to be a bit different. When my service gets instantiated, it opens a database connection once, does some work, closes the connection and returns the result. Then it gets torn down by the WCF, and the next incoming call creates a new instance of the service. In other words, my service gets instantiated per client call, as in [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)]. The service accesses an SQL Server 2008 database. I'm using .NET framework 3.5 SP1. Does the connection pooling still work in this scenario, or I need to roll my own connection pool in form of a singleton or by some other means (IInstanceContextProvider?). I would rather avoid reinventing the wheel, if possible.

  Read the article

• Splitting build cross the network?

  - by Dandikas

  Is there a known solution for splitting build process cross the network machines? Use case: We are an average software development company. We own around 50 development workstations (Quad Core 2.66Ghz, 4 GB ram, 200 GB raid). No need to tell that at any single moment not every machine is loaded to the max. There are 5 to 15 projects running simultaneously at any single moment. Obviously all of them are continuously build on server, than deployed to proper environment. Single project build is taking from 3 to 15 minutes. The problem: Whenever we build 5 projects in a row the last project is going to be ready after around 25 - 50 minutes. Building in parallel does not solve the problem (build is only a part of the game, than you need to deploy, run tests etc.) YES the correct solution is to add another build server, but "That involves buying new Expensive hardware, and we already spent a lot!". Yea, right(damn them)! Anyway. What about splitting build among developers workstation? Lets say whenever we need to build project "A" we check 5 workstations and start build on all that are not overloaded. The build can be canceled by a developer if he really needs all the power of his machine as long as there is at least 1 machine that is still building. After build is finished deployment can be performed to a proper environment (hosted on some server, not on workstation :) ). The bigger the company the more this makes sense to me. Anyone tried something like this? Are there any good practices? Any helpful software? (90% of the projects are .net C#)

  Read the article

• Existing LINQ extension method similar to Parallel.For?

  - by Joel Martinez

  The linq extension methods for ienumerable are very handy ... but not that useful if all you want to do is apply some computation to each item in the enumeration without returning anything. So I was wondering if perhaps I was just missing the right method, or if it truly doesn't exist as I'd rather use a built-in version if it's available ... but I haven't found one :-) I could have sworn there was a .ForEach method somewhere, but I have yet to find it. In the meantime, I did write my own version in case it's useful for anyone else: using System.Collections; using System.Collections.Generic; public delegate void Function<T>(T item); public delegate void Function(object item); public static class EnumerableExtensions { public static void For(this IEnumerable enumerable, Function func) { foreach (object item in enumerable) { func(item); } } public static void For<T>(this IEnumerable<T> enumerable, Function<T> func) { foreach (T item in enumerable) { func(item); } } } usage is: myEnumerable.For<MyClass>(delegate(MyClass item) { item.Count++; });

  Read the article

• PDO Database Connections Problem

  - by Metropolis

  Hey Everyone, Over a year ago I created my own database classes which use PDO, and handle all preparing, executing, and closing connections. These classes have been working great up until now. There are two different database severs I am grabbing from, MySQL, and MS SQL Express. I am retrieving an employee id from the MySQL server and using it to get that employees information from the MS SQL server. There are about 11k records coming from the MySQL server and my program is only making it through 1200 before crashing with an error like the following. Connection failed (odbc:Driver=FreeTDS;Servername=MSSQLExpress;Database=SMDINC) Class (PDOException) SQLSTATE[08001] SQLDriverConnect: 0 [unixODBC][FreeTDS][SQL Server]Unable to connect to data source It seems like the program is not able to connect to the data source, but it is running the exact same query about 30 times before this and having no problem. Also, I have thoroughly checked all of the data coming into the query and it all looks fine. I believe the issue may be that there are to many connections being created, but I have tried to close all connections in many different places, and nothing seems to be fixing the problem. Any debugging help, or suggestions would be appreciated! Craig Metrolis

  Read the article

• Python 3.0 IDE - Komodo and Eclipse both flaky?

  - by victorhooi

  heya, I'm trying to find a decent IDE that supports Python 3.x, and offers code completion/in-built Pydocs viewer, Mercurial integration, and SSH/SFTP support. Anyhow, I'm trying Pydev, and I open up a .py file, it's in the Pydev perspective and the Run As doesn't offer any options. It does when you start a Pydev project, but I don't want to start a project just to edit one single Python script, lol, I want to just open a .py file and have It Just Work... Plan 2, I try Komodo 6 Alpha 2. I actually quite like Komodo, and it's nice and snappy, offers in-built Mercurial support, as well as in-built SSH support (although it lacks SSH HTTP Proxy support, which is slightly annoying). However, for some reason, this refuses to pick up Python 3. In Edit-Preferences-Languages, there's two option, one for Python and Python3, but the Python3 one refuses to work, with either the official Python.org binaries, or ActiveState's own ActivePython 3. Of course, I can set the "Python" interpreter to the 3.1 binary, but that's an ugly hack and breaks Python 2.x support. So, does anybody who uses an IDE for Python have any suggestions on either of these accounts, or can you recommend an alternate IDE for Python 3.0 development? Cheers, Victor

  Read the article

• protecting COM interfaces from exceptions

  - by rmeador

  I have several dozen objects exposed through COM interfaces, each of which with many methods, totaling a few hundred methods. These interfaces expose business objects from my app to a scripting engine. I have been given the task of protecting every single one of these methods from exceptions being thrown (to catch them and return an error using COM's Error() function, which incidentally I can find no documentation on because it's impossible to google). To my understanding, this requires that I add a try/catch around the guts of each one of these methods. The catch blocks are going to be similar or identical for each and every one of these hundreds of methods, which strongly smells of a problem (massively violates the DRY principle), but I can't think of any way to avoid changing every method. As far as I can tell, these methods are invoked directly by COM, with no intervening code that I can hook into to catch the exceptions. My current best idea is to make a macro for the catch block, but that has it's own sort of code-smell. Can anyone come up with a better approach? BTW, my app's exceptions do not derive from std::exception, so if there is some way of COM automatically handling standard exceptions, it won't help. And I sadly cannot change the existing exceptions to derive from std::exception.

  Read the article

• How to access a superclass's class attributes in Python?

  - by Brecht Machiels

  Have a look at the following code: class A(object): defaults = {'a': 1} def __getattr__(self, name): print('A.__getattr__') return self.get_default(name) @classmethod def get_default(cls, name): # some debug output print('A.get_default({}) - {}'.format(name, cls)) try: print(super(cls, cls).defaults) # as expected except AttributeError: #except for the base object class, of course pass # the actual function body try: return cls.defaults[name] except KeyError: return super(cls, cls).get_default(name) # infinite recursion #return cls.__mro__[1].get_default(name) # this works, though class B(A): defaults = {'b': 2} class C(B): defaults = {'c': 3} c = C() print('c.a =', c.a) I have a hierarchy of classes each with its own dictionary containing some default values. If an instance of a class doesn't have a particular attribute, a default value for it should be returned instead. If no default value for the attribute is contained in the current class's defaults dictionary, the superclass's defaults dictionary should be searched. I'm trying to implement this using the recursive class method get_default. The program gets stuck in an infinite recursion, unfortunately. My understanding of super() is obviously lacking. By accessing __mro__, I can get it to work properly though, but I'm not sure this is a proper solution. I have the feeling the answer is somewhere in this article, but I haven't been able to find it yet. Perhaps I need to resort to using a metaclass?

  Read the article

• NSUndoManager, Core Data and selective undo/redo

  - by Combat

  I'm working on a core data application that has a rather large hierarchy of managed objects similar to a tree. When a base object is created, it creates a few child objects which in turn create their own child objects and so on. Each of these child objects may gather information using NSURLConnections. Now, I'd like to support undo/redo with the undoManager in the managedObjectContext. The problem is, if a user creates a base object, then tries to undo that action, the base object is not removed. Instead, one or more of the child objects may be removed. Obviously this type of action is unpredictable and unwanted. So I tried disabling undo registration by default. I did this by calling disableUndoRegistration: before anything is modified in the managedObjectContext. Then, enabling undo registration before base operations such as creating a base object the again re-disabling registrations afterwords. Now when i try to undo, I get this error: undo: NSUndoManager 0x1026428b0 is in invalid state, undo was called with too many nested undo groups Thoughts?

  Read the article

< Previous Page | 629 630 631 632 633 634 635 636 637 638 639 640  | Next Page >