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  • JDK-7 SwingWorker deadlocks?

    - by kd304
    I have a small image processing application which does multiple things at once using SwingWorker. However, if I run the following code (oversimplified excerpt), it just hangs on JDK 7 b70 (windows) but works in 6u16. It starts a new worker within another worker and waits for its result (the real app runs multiple sub-workers and waits for all this way). Did I use some wrong patterns here (as mostly there is 3-5 workers in the swingworker-pool, which has limit of 10 I think)? import javax.swing.SwingUtilities; import javax.swing.SwingWorker; public class Swing { static SwingWorker<String, Void> getWorker2() { return new SwingWorker<String, Void>() { @Override protected String doInBackground() throws Exception { return "Hello World"; } }; } static void runWorker() { SwingWorker<String, Void> worker = new SwingWorker<String, Void>() { @Override protected String doInBackground() throws Exception { SwingWorker<String, Void> sw2 = getWorker2(); sw2.execute(); return sw2.get(); } }; worker.execute(); try { System.out.println(worker.get()); } catch (Exception e) { e.printStackTrace(); } } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { runWorker(); } }); } }

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  • Django deployment - can't import app.urls

    - by hora
    I just moved a django project to a deployment server from my dev server, and I'm having some issues deploying it. My apache config is as follows: <Location "/"> Order allow,deny Allow from all SetHandler python-program PythonHandler django.core.handlers.modpython SetEnv DJANGO_SETTINGS_MODULE project.settings PythonDebug On PythonPath "['/home/django/'] + sys.path" </Location> Django does work, since it renders the Django debug views, but I get the following error: ImportError at / No module named app.urls And here is all the information Django gives me: Request Method: GET Request URL: http://myserver.com/ Django Version: 1.1.1 Python Version: 2.6.5 Installed Applications: ['django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.sites', 'django.contrib.admin', 'django.contrib.admindocs', 'project.app'] Installed Middleware: ('django.middleware.common.CommonMiddleware', 'django.contrib.sessions.middleware.SessionMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware') Traceback: File "/usr/lib64/python2.6/site-packages/django/core/handlers/base.py" in get_response 83. request.path_info) File "/usr/lib64/python2.6/site-packages/django/core/urlresolvers.py" in resolve 218. sub_match = pattern.resolve(new_path) File "/usr/lib64/python2.6/site-packages/django/core/urlresolvers.py" in resolve 216. for pattern in self.url_patterns: File "/usr/lib64/python2.6/site-packages/django/core/urlresolvers.py" in _get_url_patterns 245. patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module) File "/usr/lib64/python2.6/site-packages/django/core/urlresolvers.py" in _get_urlconf_module 240. self._urlconf_module = import_module(self.urlconf_name) File "/usr/lib64/python2.6/site-packages/django/utils/importlib.py" in import_module 35. __import__(name) Exception Type: ImportError at / Exception Value: No module named app.urls Any ideas as to why I get an import error?

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  • SIMPLE PHP MVC Framework!

    - by Allen
    I need a simple and basic MVC example to get me started. I dont want to use any of the available packaged frameworks. I am in need of a simple example of a simple PHP MVC framework that would allow, at most, the basic creation of a simple multi-page site. I am asking for a simple example because I learn best from simple real world examples. Big popular frameworks (such as code ignighter) are to much for me to even try to understand and any other "simple" example I have found are not well explained or seem a little sketchy in general. I should add that most examples of simple MVC frameworks I see use mod_rewrite (for URL routing) or some other Apache-only method. I run PHP on IIS. I need to be able to understand a basic MVC framework, so that I could develop my own that would allow me to easily extend functionality with classes. I am at the point where I understand basic design patterns and MVC pretty well. I understand them in theory, but when it comes down to actually building a real world, simple, well designed MVC framework in PHP, i'm stuck. I would really appreciate some help! Edit: I just want to note that I am looking for a simple example that an experienced programmer could whip up in under an hour. I mean simple as in bare bones simple. I dont want to use any huge frameworks, I am trying to roll my own. I need a decent SIMPLE example to get me going.

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  • How to organize the work when project needs to be re-implemented due to poor code quality?

    - by Dmitriy Nagirnyak
    Hi, I have joined a very small where one main developer has been buiding the web app (.NET 4.0) during ~6 months. The project should be delivered within next 2 months. After first look at the code I can say that I would never allow it to go to production (things like catch { }, not tests at all with WebForms etc). So the code quality is incredibly low. My task is to improve that and still deliver the solution. So I plan to start with unit testing and MVC2 reimplementing most of the functionality (though using some of the existing code). I estimate that I will need about 6 weeks to catch up with the current progress and be on te same functionality level as the application will be in 6 months. The problem is that the main developer who has been working on the project does not seem to be very 'professional' and skillful (he seems to be really starting in IT and many basic things are unknown to him). It will take significant amount of time and effort to educate him how to do the proper testing, development and apply some patterns. I am ready to take responsibility for the reimplemnting the application but at the same time I don't want the main developer to be on idle but as he won't be able to significantly contribute to the better-world project at this stage I am not sure what would the best way to keep productivity high for both of us. Currently I think following solution is good enough: He proceeds doing what he does until I will catch up with him and then start working on a new project together. The problem is that of course this approach is not very productive as one developer will do better-world project while the other will proceed with what he did, effectively doing similar tasks. Can you suggest how we could better organise the work together in order to be most efficient for the overall project? Thanks, Dmitriy.

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  • jruby rubygems update breaks jgem

    - by brad
    Has anyone seen this: ?? No jgem command works at all?? Though jruby -S gem list does work. I'm using jruby 1.3.1 and Sun Java6 jre root@test:/usr/local: jgem --version 1.3.3 root@test:/usr/local: jgem update --system JRuby limited openssl loaded. gem install jruby-openssl for full support. http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL Updating RubyGems Updating rubygems-update Successfully installed rubygems-update-1.3.6 /usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems/commands/update_command.rb:103:Warning: Gem::SourceIndex#search support for String patterns is deprecated Updating RubyGems to 1.3.6 Installing RubyGems 1.3.6 RubyGems 1.3.6 installed root@test:/usr/local: jgem list /usr/local/jruby/bin/jgem: line 8: require: command not found /usr/local/jruby/bin/jgem: line 9: require: command not found /usr/local/jruby/bin/jgem: line 10: require: command not found /usr/local/jruby/bin/jgem: line 12: required_version: command not found /usr/local/jruby/bin/jgem: line 14: unless: command not found /usr/local/jruby/bin/jgem: line 15: abort: command not found /usr/local/jruby/bin/jgem: line 16: end: command not found /usr/local/jruby/bin/jgem: line 18: args: command not found /usr/local/jruby/bin/jgem: line 20: begin: command not found /usr/local/jruby/bin/jgem: line 21: Gem::GemRunner.new.run: command not found /usr/local/jruby/bin/jgem: line 22: rescue: command not found /usr/local/jruby/bin/jgem: line 23: exit: e.exit_code: numeric argument required

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  • xVal and Regular Expression Match

    - by gmcalab
    I am using xVal to validate my forms in asp.net MVC 1.0 Not sure why my regular expression isn't validating correctly. It validates with the value of "12345" It validates with the value of "12345 " It validates with the value of "12345 -" It validates with the value of "12345 -1" It validates with the value of "12345 -12" ... etc For a zip code I expect one of the two patterns: 12345 or 12345 -1234 Here are the two regex I tried: (\d{5})((( -)(\d{4}))?) (\d{5})|(\d{5} -\d{4}) Here is my MetaData class for xVal [MetadataType(typeof(TIDServiceMetadata))] public class TIDServiceStep : TIDDetail { public class TIDServiceMetadata { [Required(ErrorMessage = " [Required] ")] [RegularExpression(@"(\d{5})|(\d{5} -\d{4})", ErrorMessage = " Invalid Zip ")] public string Zip { get; set; } } } Here is my aspx page: <% Html.BeginForm("Edit", "Profile", FormMethod.Post); %> <table border="0" cellpadding="0" cellspacing="0"> <tr> <td> <h6>Zip:</h6> </td> <td> <%= Html.TextBox("Profile.Zip")%> </td> </tr> <tr> <td> <input type="submit"/> </td> </tr> </table> <% Html.EndForm(); %> <% Html.Telerik().ScriptRegistrar() .OnDocumentReady(() => { %> <%= Html.ClientSideValidation<TIDProfileStep>("Profile").SuppressScriptTags() %> <% }); %>

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  • The IOC "child" container / Service Locator

    - by Mystagogue
    DISCLAIMER: I know there is debate between DI and service locator patterns. I have a question that is intended to avoid the debate. This question is for the service locator fans, who happen to think like Fowler "DI...is hard to understand...on the whole I prefer to avoid it unless I need it." For the purposes of my question, I must avoid DI (reasons intentionally not given), so I'm not trying to spark a debate unrelated to my question. QUESTION: The only issue I might see with keeping my IOC container in a singleton (remember my disclaimer above), is with the use of child containers. Presumably the child containers would not themselves be singletons. At first I thought that poses a real problem. But as I thought about it, I began to think that is precisely the behavior I want (the child containers are not singletons, and can be Disposed() at will). Then my thoughts went further into a philosophical realm. Because I'm a service locator fan, I'm wondering just how necessary the notion of a child container is in the first place. In a small set of cases where I've seen the usefulness, it has either been to satisfy DI (which I'm mostly avoiding anyway), or the issue was solvable without recourse to the IOC container. My thoughts were partly inspired by the IServiceLocator interface which doesn't even bother to list a "GetChildContainer" method. So my question is just that: if you are a service locator fan, have you found that child containers are usually moot? Otherwise, when have they been essential? extra credit: If there are other philosophical issues with service locator in a singleton (aside from those posed by DI advocates), what are they?

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  • Proper way to validate model in ASP.NET MVC 2 and ViewModel apporach

    - by adrin
    I am writing an ASP.NET MVC 2 application using NHibernate and repository pattern. I have an assembly that contains my model (business entities), moreover in my web project I want to use flattened objects (possibly with additional properties/logic) as ViewModels. These VMs contain UI-specific metadata (eg. DisplayAttribute used by Html.LabelFor() method). The problem is that I don't know how to implement validation so that I don't repeat myself throughout various tiers (specifically validation rules are written once in Model and propagated to ViewModel). I am using DataAnnotations on my ViewModel but this means no validation rules are imposed on the Model itself. One approach I am considering is deriving ViewModel objects from business entities adding new properties/overriding old ones, thus preserving validation metadata between the two however this is an ugly workaround. I have seen Automapper project which helps to map properties, but I am not sure if it can handle ASP.NET MVC 2 validation metadata properly. Is it difficult to use custom validation framework in asp.net mvc 2? Do you have any patterns that help to preserve DRY in regard to validation?

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  • A function where small changes in input always result in large changes in output

    - by snowlord
    I would like an algorithm for a function that takes n integers and returns one integer. For small changes in the input, the resulting integer should vary greatly. Even though I've taken a number of courses in math, I have not used that knowledge very much and now I need some help... An important property of this function should be that if it is used with coordinate pairs as input and the result is plotted (as a grayscale value for example) on an image, any repeating patterns should only be visible if the image is very big. I have experimented with various algorithms for pseudo-random numbers with little success and finally it struck me that md5 almost meets my criteria, except that it is not for numbers (at least not from what I know). That resulted in something like this Python prototype (for n = 2, it could easily be changed to take a list of integers of course): import hashlib def uniqnum(x, y): return int(hashlib.md5(str(x) + ',' + str(y)).hexdigest()[-6:], 16) But obviously it feels wrong to go over strings when both input and output are integers. What would be a good replacement for this implementation (in pseudo-code, python, or whatever language)?

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  • Setting up DrJava to work through Friedman / Felleisen "A Little Java"

    - by JDelage
    All, I'm going through the Friedman & Felleisen book "A Little Java, A Few Patterns". I'm trying to type the examples in DrJava, but I'm getting some errors. I'm a beginner, so I might be making rookie mistakes. Here is what I have set-up: public class ALittleJava { //ABSTRACT CLASS POINT abstract class Point { abstract int distanceToO(); } class CartesianPt extends Point { int x; int y; int distanceToO(){ return((int)Math.sqrt(x*x+y*y)); } CartesianPt(int _x, int _y) { x=_x; y=_y; } } class ManhattanPt extends Point { int x; int y; int distanceToO(){ return(x+y); } ManhattanPt(int _x, int _y){ x=_x; y=_y; } } } And on the main's side: public class Main{ public static void main (String [] args){ Point y = new ManhattanPt(2,8); System.out.println(y.distanceToO()); } } The compiler cannot find the symbols Point and ManhattanPt in the program. If I precede each by ALittleJava., I get another error in the main, i.e., an enclosing instance that contains ALittleJava.ManhattanPt is required I've tried to find ressources on the 'net, but the book must have a pretty confidential following and I couldn't find much. Thank you all. JDelage

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  • registration 0.8 alpha activation problem

    - by craphunter
    Got the following error: Exception Type: TypeError at /accounts/account/activate/success/ Exception Value: activate() takes at least 2 non-keyword arguments (1 given) My view: def activate(request, backend, template_name='registration/activation_complete.html', success_url=None, extra_context=None, **kwargs): backend = get_backend(backend) account = backend.activate(request, **kwargs) if account: if success_url is None: to, args, kwargs = backend.post_activation_redirect(request, account) return redirect(to, *args, **kwargs) else: return redirect(success_url) if extra_context is None: extra_context = {} context = RequestContext(request) for key, value in extra_context.items(): context[key] = callable(value) and value() or value return render_to_response(template_name, kwargs, context_instance=context) My url: urlpatterns = patterns('', url(r'^activate/complete/$', direct_to_template, { 'template': 'registration/activation_complete.html' }, name='registration_activation_complete'), # Activation keys get matched by \w+ instead of the more specific # [a-fA-F0-9]{40} because a bad activation key should still get to the view; # that way it can return a sensible "invalid key" message instead of a # confusing 404. url(r'^activate/(?P<activation_key>\w+)/$', activate, { 'backend': 'registration.backends.default.DefaultBackend' }, name='registration_activate'), url(r'^register/$', register, { 'backend': 'registration.backends.default.DefaultBackend' }, name='registration_register'), url(r'^register/complete/$', direct_to_template, { 'template': 'registration/registration_complete.html' }, name='registration_complete'), url(r'^register/closed/$', direct_to_template, { 'template': 'registration/registration_closed.html' }, name='registration_disallowed'), (r'', include('registration.auth_urls')), url(r'^account/activate/(?P<activation_key>\w+)/$', 'registration.views.activate', {'success_url': 'account/activate/success/'}, name='registration_activate2'), url(r'^account/activate/success/$', direct_to_template, {'template': 'registration/activation_complete.html'}, name='registration_activation_complete'), ) What do I do wrong? Thanks!

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  • How to arrange business logic in a Kohana 3 project

    - by Pekka
    I'm looking for advice, tutorials and links at how to set up a mid-sized web application with Kohana 3. I have implemented MVC patterns in the past but never worked against a "formalized" MVC framework so I'm still getting my head around the terminology - toying around with basic examples, building views and templates, and so on. I'm progressing fairly well but I want to set up a real-world web project (one of my own that I've been planning for quite some time now) as a learning object. I learn best by example, but example-based documentation is a bit sparse for Kohana 3 right now - they say so themselves on the site. While I'm not worried about learning the framework as I go along, I want to make sure the code base is healthily structured from the start - i.e. controllers are split nicely, named well and according to standards, and most importantly the business logic is separated into appropriately sized models. My application could, in its core, be described as a business directory with a range of search and listing functions, and a login area for each entry owner. The actual administrative database backend is already taken care of. Supposing I have all the API worked out and in place already - list all businesses, edit business, list businesses by street name, create offer logged in as business, and so on, and I'm just looking for how to fit the functionality into a MVC pattern and into a Kohana application structure that can be easily extended. Do you know real-life examples of "database-heavy" applications like directories, online communities... with a log-in area built on Kohana 3, preferably Open Source so I could take a peek how they do it? Are there conventions or best practices on how to structure an extendable login area for end users in a Kohana project that is not only able to handle a business directory page, but further products on separate pages as well? Do you know any good resources on building complex applications with Kohana? Have you built something similar and could give me recommendations on a project structure?

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  • Any book on designing and implementing a CRPG engine?

    - by Fabzter
    Hi! First, let me tell you, I am not really interested in making my own rpg engine (at least not in the near future, hehe), but I do feel like I want to understand the internals of how a rpg engine works. Why? Well, because I like to read about programming and design, It keeps me motivated and excited, and because I know I will learn a lot, for, even when I have been programming for some years now, I never stop considering myself an ignorant... there are simply SO many things involving a game engine (specially rpg ones, like branching storylines, and items and economics!) I'm eager to know. I've been searching (and thus, finding) lots of info online, but it is never focused in what I'm interested (most of it talks about the mathematics and AI algorithms implementation, which I know quite well), which is the design of overall structure, patterns, scripting engine, decision engine... damn, so many things I can't even imagine, since I've never done any game programming. I hope you know have an idea of how I feel, and how I want to learn for the sake of learning, and why would I want you to tell me if you know if there exist books touching the topics that interest me the most.

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  • Django: Named URLs / Same Template, Different Named URL

    - by TheLizardKing
    I have a webapp that lists all of my artists, albums and songs when the appropriate link is clicked. I make extensive use of generic views (object_list/detail) and named urls but I am coming across an annoyance. I have three templates that pretty much output the exact same html that look just like this: {% extends "base.html" %} {% block content %} <div id="content"> <ul id="starts-with"> {% for starts_with in starts_with_list %} <li><a href="{% url song_list_x starts_with %}">{{ starts_with|upper }}</a></li> {% endfor %} </ul> <ul> {% for song in songs_list %} <li>{{ song.title }}</li> {% endfor %} </ul> </div> {% endblock content %} My artist and album template look pretty much the same and I'd like to combine the three template's into one. The fact that my variables start with song can easily be changed to the default obj. It's my <ul id="starts-with"> named url I don't know how to correct. Obviously I want it to link to a specific album/artist/song using the named urls in my urls.py but I don't know how to make it context aware. Any suggestions? urlpatterns = patterns('tlkmusic.apps.tlkmusic_base.views', # (r'^$', index), url(r'^artists/$', artist_list, name='artist_list'), url(r'^artists/(?P<starts_with>\w)/$', artist_list, name='artist_list_x'), url(r'^artist/(?P<artist_id>\d+)/$', artist_detail, name='artist_detail'), url(r'^albums/$', album_list, name='album_list'), url(r'^albums/(?P<starts_with>\w)/$', album_list, name='album_list_x'), url(r'^songs/$', song_list, name='song_list'), url(r'^songs/(?P<starts_with>\w)/$', song_list, name='song_list_x'), )

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  • Architecture with NHibernate and Repositories

    - by Matthew
    I've been reading up on MVC 2 and the recommended patterns, so far I've come to the conclusion (amongst much hair pulling and total confusion) that: Model - Is just a basic data container Repository - Provides data access Service - Provides business logic and acts as an API to the Controller The Controller talks to the Service, the Service talks to the Repository and Model. So for example, if I wanted to display a blog post page with its comments, I might do: post = PostService.Get(id); comments = PostService.GetComments(post); Or, would I do: post = PostService.Get(id); comments = post.Comments; If so, where is this being set, from the repository? the problem there being its not lazy loaded.. that's not a huge problem but then say I wanted to list 10 posts with the first 2 comments for each, id have to load the posts then loop and load the comments which becomes messy. All of the example's use "InMemory" repository's for testing and say that including db stuff would be out of scope. But this leaves me with many blanks, so for a start can anyone comment on the above?

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  • Help with Neuroph neural network

    - by user359708
    For my graduate research I am creating a neural network that trains to recognize images. I am going much more complex than just taking a grid of RGB values, downsampling, and and sending them to the input of the network, like many examples do. I actually use over 100 independently trained neural networks that detect features, such as lines, shading patterns, etc. Much more like the human eye, and it works really well so far! The problem is I have quite a bit of training data. I show it over 100 examples of what a car looks like. Then 100 examples of what a person looks like. Then over 100 of what a dog looks like, etc. This is quite a bit of training data! Currently I am running at about one week to train the network. This is kind of killing my progress, as I need to adjust and retrain. I am using Neuroph, as the low-level neural network API. I am running a dual-quadcore machine(16 cores with hyperthreading), so this should be fast. My processor percent is at only 5%. Are there any tricks on Neuroph performance? Or Java peroformance in general? Suggestions? I am a cognitive psych doctoral student, and I am decent as a programmer, but do not know a great deal about performance programming.

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  • Avoiding GC thrashing with WSE 3.0 MTOM service

    - by Leon Breedt
    For historical reasons, I have some WSE 3.0 web services that I cannot upgrade to WCF on the server side yet (it is also a substantial amount of work to do so). These web services are being used for file transfers from client to server, using MTOM encoding. This can also not be changed in the short term, for reasons of compatibility. Secondly, they are being called from both Java and .NET, and therefore need to be cross-platform, hence MTOM. How it works is that an "upload" WebMethod is called by the client, sending up a chunk of data at a time, since files being transferred could potentially be gigabytes in size. However, due to not being able to control parts of the stack before the WebMethod is invoked, I cannot control the memory usage patterns of the web service. The problem I am running into is for file sizes from 50MB or so onwards, performance is absolutely killed because of GC, since it appears that WSE 3.0 buffers each chunk received from the client in a new byte[] array, and by the time we've done 50MB we're spending 20-30% of time doing GC. I've played with various chunk sizes, from 16k to 2MB, with no real great difference in results. Smaller chunks are killed by the latency involved with round-tripping, and larger chunks just postpone the slowdown until GC kicks in. Any bright ideas on cutting down on the garbage created by WSE? Can I plug into the pipeline somehow and jury-rig something that has access to the client's request stream and streams it to the WebMethod? I'm aware that it is possible to "stream" responses to the client using WSE (albeit very ugly), but this problem is with requests from the client.

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  • Is there a way to avoid spaghetti code over the years?

    - by Yoni Roit
    I've had several programming jobs. Each one with 20-50 developers, project going on for 3-5 years. Every time it's the same. Some programmers are bright, some are average. Everyone has their CS degree, everyone read design patterns. Intentions are good, people are trying hard to write good code but still after a couple of years the code turns into spaghetti. Changes in module A suddenly break module B. There are always these parts of code that no one can understand except for the person who wrote it. Changing infrastructure is impossible and backwards compatibility issues prevent good features to get in. Half of the time you just want to rewrite everything from scratch. And people more experienced than me treat this as normal. Is it? Does it have to be? What can I do to avoid this or should I accept it as a fact of life? Edit: Guys, I am impressed with the amount and quality of responses here. This site and its community rock!

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  • preg_match_all and newlines inside quotes

    - by David
    Another noob regex problem/question. I'm probably doing something silly so I thought I'd exploit the general ingenuity of the SO regulars ;) Trying to match newlines but only if they occur within either double quotes or single quotes. I also want to catch strings that are between quotes but contain no newlines. Okay so there's what i got, with output. Below that, will be the output I would like to get. Any help would be greatly appreciated! :) I use Regex Coach to help me create my patterns, being a novice and all. According to RC, The pattern I supply does match all occurances within the data, but in my PHP, it skips over the multi-line part. I have tried with the 'm' pattern modifier already, to no avail. Contents of $CompressedData: <?php $Var = "test"; $Var2 = "test2"; $Var3 = "blah blah blah blah blah blah blah blah blah"; $Var4 = "hello"; ?> Pattern / Code: preg_match_all('!(\'|")(\b.*\b\n*)*(\'|")!', $CompressedData, $Matches); Current print_r output of $Matches: Array ( [0] => Array ( [0] => "test" [1] => "test2" [2] => "hello" ) ... } DESIRED print_r output of $Matches: Array ( [0] => Array ( [0] => "test" [1] => "test2" [2] => "blah blah blah blah blah blah blah blah blah" [3] => "hello" ) ... }

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  • DAL Layer : EF 4.0 or Normal Data access layer with Stored Procedure

    - by Harryboy
    Hello Experts, Application : I am working on one mid-large size application which will be used as a product, we need to decide on our DAL layer. Application UI is in Silverlight and DAL layer is going to be behind service layer. We are also moving ahead with domain model, so our DB tables and domain classes are not having same structure. So patterns like Data Mapper and Repository will definitely come into picture. I need to design DAL Layer considering below mentioned factors in priority manner Speed of Development with above average performance Maintenance Future support and stability of the technology Performance Limitation : 1) As we need to strictly go ahead with microsoft, we can not use NHibernate or any other ORM except EF 4.0 2) We can use any code generation tool (Should be Open source or very cheap) but it should only generate code in .Net, so there would not be any licensing issue on per copy basis. Questions I read so many articles about EF 4.0, on outset it looks like that it is still lacking in features from NHibernate but it is considerably better then EF 1.0 So, Do you people feel that we should go ahead with EF 4.0 or we should stick to ADO .Net and use any code geneartion tool like code smith or any other you feel best Also i need to answer questions like what time it will take to port application from EF 4.0 to ADO .Net if in future we stuck up with EF 4.0 for some features or we are having serious performance issue. In reverse case if we go ahead and choose ADO .Net then what time it will take to swith to EF 4.0 Lastly..as i was going through the article i found the code only approach (with POCO classes) seems to be best suited for our requirement as switching is really easy from one technology to other. Please share your thoughts on the same and please guide on the above questions

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  • EF + UnitOfWork + SharePoint RunWithElevatedPrivileges

    - by Lorenzo
    In our SharePoint application we have used the UnitOfWork + Repository patterns together with Entity Framework. To avoid the usage of the passthrough authentication we have developed a piece of code that impersonate a single user before creating the ObjectContext instance in a similar way that is described in "Impersonating user with Entity Framework" on this site. The only difference between our code and the referred question is that, to do the impersonation, we are using RunWithElevatedPrivileges to impersonate the Application Pool identity as in the following sample. SPSecurity.RunWithElevatedPrivileges(delegate() { using (SPSite site = new SPSite(url)) { _context = new MyDataContext(ConfigSingleton.GetInstance().ConnectionString); } }); We have done this way because we expected that creating the ObjectContext after impersonation and, due to the fact that Repositories are receiving the impersonated ObjectContext would solve our requirement. Unfortunately it's not so easy. In fact we experienced that, even if the ObjectContext is created before and under impersonation circumstances, the real connection is made just before executing the query, and so does not use impersonation, which break our requirement. I have checked the ObjectContext class to see if there was any event through which we can inject the impersonation but unfortunately found nothing. Any help?

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  • Pattern for limiting number of simultaneous asynchronous calls

    - by hitch
    I need to retrieve multiple objects from an external system. The external system supports multiple simultaneous requests (i.e. threads), but it is possible to flood the external system - therefore I want to be able to retrieve multiple objects asynchronously, but I want to be able to throttle the number of simultaneous async requests. i.e. I need to retrieve 100 items, but don't want to be retrieving more than 25 of them at once. When each request of the 25 completes, I want to trigger another retrieval, and once they are all complete I want to return all of the results in the order they were requested (i.e. there is no point returning the results until the entire call is returned). Are there any recommended patterns for this sort of thing? Would something like this be appropriate (pseudocode, obviously)? private List<externalSystemObjects> returnedObjects = new List<externalSystemObjects>; public List<externalSystemObjects> GetObjects(List<string> ids) { int callCount = 0; int maxCallCount = 25; WaitHandle[] handles; foreach(id in itemIds to get) { if(callCount < maxCallCount) { WaitHandle handle = executeCall(id, callback); addWaitHandleToWaitArray(handle) } else { int returnedCallId = WaitHandle.WaitAny(handles); removeReturnedCallFromWaitHandles(handles); } } WaitHandle.WaitAll(handles); return returnedObjects; } public void callback(object result) { returnedObjects.Add(result); }

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  • Entity Framework 4 / POCO - Where to start?

    - by Basiclife
    Hi, I've been programming for a while and have used LINQ-To-SQL and LINQ-To-Entities before (although when using entities it has been on a Entity/Table 1-1 relationship - ie not much different than L2SQL) I've been doing a lot of reading about Inversion of Control, Unit of Work, POCO and repository patterns and would like to use this methodology in my new applications. Where I'm struggling is finding a clear, concise beginners guide for EF4 which doesn't assume knowledge of EF1. The specific questions I need answered are: Code first / model first? Pros/cons in regards to EF4 (ie what happens if I do code first, change the code at a later date and need to regenerate my DB model - Does the data get preserved and transformed or dropped?) Assuming I'm going code-first (I'd like to see how EF4 converts that to a DB schema) how do I actually get started? Quite often I've seen articles with entity diagrams stating "So this is my entity model, now I'm going to ..." - Unfortunately, I'm unclear if they're created the model in the designer, saved it to generate code then stopped any further auto-code generation -or- They've coded (POCO)? classes and the somehow imported them into the deisgner view? I suppose what I really need is an understanding of where the "magic" comes from and how to add it myself if I'm not just generating an EF model directly from a DB. I'm aware the question is a little vague but I don't know what I don't know - So any input / correction / clarification appreciated. Needless to say, I don't expect anyone to sit here and teach me EF - I'd just like some good tutorials/forums/blogs/etc. for complete entity newbies Many thanks in advance

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  • DDD and MVC: Difference between 'Model' and 'Entity'

    - by Nathan Loding
    I'm seriously confused about the concept of the 'Model' in MVC. Most frameworks that exist today put the Model between the Controller and the database, and the Model almost acts like a database abstraction layer. The concept of 'Fat Model Skinny Controller' is lost as the Controller starts doing more and more logic. In DDD, there is also the concept of a Domain Entity, which has a unique identity to it. As I understand it, a user is a good example of an Entity (unique userid, for instance). The Entity has a life-cycle -- it's values can change throughout the course of the action -- and then it's saved or discarded. The Entity I describe above is what I thought Model was supposed to be in MVC? How off-base am I? To clutter things more, you throw in other patterns, such as the Repository pattern (maybe putting a Service in there). It's pretty clear how the Repository would interact with an Entity -- how does it with a Model? Controllers can have multiple Models, which makes it seem like a Model is less a "database table" than it is a unique Entity. So, in very rough terms, which is better? No "Model" really ... class MyController { public function index() { $repo = new PostRepository(); $posts = $repo->findAllByDateRange('within 30 days'); foreach($posts as $post) { echo $post->Author; } } } Or this, which has a Model as the DAO? class MyController { public function index() { $model = new PostModel(); // maybe this returns a PostRepository? $posts = $model->findAllByDateRange('within 30 days'); while($posts->getNext()) { echo $posts->Post->Author; } } } Both those examples didn't even do what I was describing above. I'm clearly lost. Any input?

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  • How to get rid of the GUI access from shared library.

    - by Inso Reiges
    Hello, In my project i have a shared library with cross-platform code that provides a very convenient abstraction for a number of its clients. To be more specific, this library provides data access to encrypted files generated by main application on a number of platforms. There is a great deal of complicated code there that implements cryptographic protocols and as such is very error-prone and should be shared as much as possible across clients and platforms. However parsing all this encrypted stuff requires asking user for a number of different secrets ones in a while. The secret can be either a password, a number of shared passwords or a public key file and this list is a hot target for extension in the future. I can't really ask the user for any of those secrets beforehand from main application, because i really don't know what i need to ask for until i start working with the encrypted data directly in the library code. So i will have to create dialogs and call them from the library code. However i really see this as a bad idea, because (among other things) there is a possibility of a windows service using it and services can't have GUI access. The question is, are there any known ways or patterns to get rid of the GUI calls that are suitable for my case? Thank you.

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