Search Results

Search found 3321 results on 133 pages for 'patterns'.

Page 108/133 | < Previous Page | 104 105 106 107 108 109 110 111 112 113 114 115  | Next Page >

• JPA in distributed Java EE configuration

  - by sof

  Hello, I'm developing a JEE application to run on Glassfish: Database (javaDB, MS SQL, MySQL or Oracle) EJB layer with JPA (Toplink essentials - from Glassfish) for database access JSF/Icefaces based web UI accessing the EJB layer The application will have a lot of concurrent web client, so I want to run it on different physical servers and use a load-balancer. My problem is now how to keep the applications synchronized. I intend to set up multiple servers, each running Glassfish with my EAR app installed. Whenever on one of the servers data is added to or removed from the database (via JPA, no direct SQL queries), this change should be reflected in the JPA layer on the other servers. I've been looking around for solutions to this, but couldn't find anything I really like (the full Toplink from Oracle claims to have a solution, but don't know). Doing a refresh before every access to a JPA entity could work, but is far from efficient. Are there any patterns, libraries, ... that could help here? Thanks a lot!

  Read the article

• Django test client gets 301 redirection when accessing url

  - by Michal Klich

  I am writing unittests for django views. I have observed that one of my views returns redirection code 301, which is not expected. Here is my views.py mentioned earlier. def index(request): return render(request, 'index.html', {'form': QueryForm()}) def query(request): if request.is_ajax(): form = QueryForm(request.POST) return HttpResponse('valid') Below is urls.py. urlpatterns = patterns('', url(r'^$', 'core.views.index'), url(r'^query/$', 'core.views.query') ) And unittest that will fail. def so_test(self): response = self.client.post('/') self.assertEquals(response.status_code, 200) response = self.client.post('/query', {}) self.assertEquals(response.status_code, 200) My question is: why there is status 301 returned?

  Read the article

• Handling exceptions, is this a good way?

  - by Jorge Córdoba

  We're struggling with a policy to correctly handle exceptions in our application. Here's our goals for it (summarized): Handle only specific exceptions. Handle only exceptions that you can correct Log only once. We've come out with a solution that involves a generic Application Specific Exception and works like this in a piece of code: try { // Do whatever } catch(ArgumentNullException ane) { // Handle, optinally log and continue } catch(AppSpecificException) { // Rethrow, don't log, don't do anything else throw; } catch(Exception e) { // Log, encapsulate (so that it won't be logged again) and throw Logger.Log("Really bad thing", e.Message, e); throw new AppSpecificException(e) } All exception is logged and then turned to an AppSpecificException so that it won't be logged again. Eventually it will reach the last resort event handler that will deal with it if it has to. I don't have so much experience with exception handling patterns... Is this a good way to solve our goals? Has it any major drawbacks or big red warnings?

  Read the article

• django threadedcomments

  - by Patrick

  Hi folks, I would like to setup a comment systems on my site, using django threadedcomments, and I follow all the steps in the Tutorial, however, I get the following error: No module named newforms.util I am not sure what causing this issue, here is my configuration: #settings.py INSTALLED_APPS = ( 'django.contrib.admin', 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.sites', 'myproject.myapp', 'threadedcomments', ) #urls.py from django.conf import settings from django.conf.urls.defaults import * from django.contrib import admin admin.autodiscover() urlpatterns = patterns('', (r'^admin/', include(admin.site.urls)), (r'^threadedcomments/', include('threadedcomments.urls')), ) Please let me know if there is another better choice for commenting, as long as the comment system is flexible and able to do lot of customization, as well as threadedcomment, of coz, integrating with Rating, I am happy to use the other one. Thanks guys.

  Read the article

• Pattern for iPhone background loading during init?

  - by Rob S.

  Hi everyone, I'm currently kicking off a background thread to do some REST queries in my app delegate's didFinishLaunchingWithOptions. This thread creates some objects and populates the model as the rest of the app continues to load (because I don't block, and didFinishLaunchingWithOptions returns YES). I also put up a loading UIViewController 'on top' of the main view that I tear down after the background initialization is complete. My problem is that I need to notify the first view (call it the Home view) that the model is ready, and that it should populate itself. The trick is that the background download could have finished before Home.viewDidAppear is called, or any of the other Home.initX methods. I'm having difficulty synchronizing all of this and I've thought about it long enough that it feels like I'm barking up the wrong tree. Are there any patterns here for this sort of thing? I'm sure other apps start by performing lengthy operations with loading screens :) Thanks!

  Read the article

• What is a common name for inheritance, composition, aggregation, delegation?

  - by Eye of Hell

  Hello. After program is separated into small object, these objects must be connected with each over. Where are different types of connection. Inheritance, composition, aggregation, delegation. These types has many kinds and patterns like loose coupling, tight coupling, inversion of control, delegation via interfaces etc. What is a correct common name for mentioned types of connections? I can suggest that they all are called 'coupling', but i can't find any good classification in google, so maybe i'm trying to use a wrong term? Maybe anyone knows a solid, trusted classification that i can user for terminology?

  Read the article

• Django - Static content display based on URL

  - by Steven Potter

  I'm working on a Django site with a basic three column design. Left column navigation, center column content and right column URL specific content blocks. My question is about the best method of controlling the URL specific content blocks in the right column. I am thinking of something along the lines of the Flatpages app that will make the content available to the template context if the URL matches a pre-determined pattern (perhaps regex?). Does anyone know if such an app already exists? If not, I am looking for some advice about the best way to implement it. Particularly in relation to the matching of patterns to the current URL. Is there any good way to re-use parts of the Django URL dispatcher for this use?

  Read the article

• frameworks for coding a php library?

  - by ajsie

  there are plenty of frameworks for coding MVC web applications. this time im going to code a library (think of Doctrine or Solr) with a bunch of class files. u just include a bootstrap or a class file and you are ready to use my classes. i have never tried to code a library before and intend to code one for learning purpose so that i can use various design patterns i have learned. are there any great frameworks for this, how i should organize the different class files, where i can put configuration files and so on? tutorials or other information would be great too. thanks

  Read the article

• Can a program have a few IFs and only one Else structures?

  - by kwokwai

  Hi all, When I was doing some JQuery and PHP, I noticed the If-else patterns were treated differently and varied from one language to another. Say I got a simple input text field in a HTML and I was using some Ifs and Elses to check the value input into the text field. Text: <input type="text" name="testing"/> In JQuery, I got some codes as follows: if($("#testing").val()==1){ //do something } if($("#testing").val()=="add"){ //do something } else{ //do something } if($("#testing").val()=="hello"){ //do something } How come JQuery and PHP treated the Else statement differently? I mean in JQuery, the third If statement was still proceeded even if it had gone to the Else statement, but it stopped after the Else statement when I repeated the code in PHP script.

  Read the article

• In c++ is there any Events/delegates/interfaces/notifications! anything?

  - by Bach

  Say i have these classes ViewA and ViewB In objective C using the delegate pattern I could do @protocol ViewBDelegate{ - (void) doSomething(); } then in ViewB interface: id<ViewBDelegate> delegate; then in ViewA implementation i set the delegate: viewB.delegate = self; and now I can call in doSomething from viewB onto any that unknown type delegate. [delegate doSomething]; "C++ How to Program" has been the worse read an can't find simple examples that demonstrates basic design patterns. What i'm looking for in C++ is: events ActionScript and java either delegates or notifications in Objective C anything that allows class A, Class B and Class C to know that ClassX didSomething()!!! thanks

  Read the article

• API verbs for an interruptible operation

  - by 280Z28

  I have a long running task as part of my application. The task can be started, paused, resumed, and cancelled. I'm trying to find the best interface for these operations. Two seem clear: Pause and Cancel. This leaves the start and resume operations. I could include both Start and Resume. This has the downside of either requiring the API consumer to check the state before starting/resuming the operation to call the right method, or making the methods aliases of each other. I'm thinking I should include either Start or Resume, but I don't know which one is the most appropriate. Does anyone have any examples in the .NET Framework of such behavior? I prefer to follow established patterns whenever they are available.

  Read the article

• JavaScript inheritance extend function

  - by Zach

  I'm having some trouble understanding the IF clause at the end of this function from Pro JavaScript Design Patterns: function extend(subClass, superClass) { var F = function() {}; F.prototype = superClass.prototype; subClass.prototype = new F(); subClass.prototype.constructor = subClass; subClass.superclass = superClass.prototype; if(superClass.prototype.constructor == Object.prototype.constructor) { superClass.prototype.constructor = superClass; } } The book explains that these lines ensure that the superclass's constructor attribute is correctly set, even if the superclass is the Object class itself. Yet, if I omit those three lines and do the following: function SubClass() {}; extend(SubClass, Object); alert(Object.prototype.constructor == Object); The alert says 'true', which means the superclass's constructor is set correctly even without those last three lines. Under what conditions, then, does this IF statement do something useful? Thanks.

  Read the article

• Porting library from Java to Python

  - by Mike Griffith

  I'm about to port a smallish library from Java to Python and wanted some advice (smallish ~ a few thousand lines of code). I've studied the Java code a little, and noticed some design patterns that are common in both languages. However, there were definitely some Java-only idioms (singletons, etc) present that are generally not-well-received in Python-world. I know at least one tool (j2py) exists that will turn a .java file into a .py file by walking the AST. Some initial experimentation yielded less than favorable results. Should I even be considering using an automated tool to generate some code, or are the languages different enough that any tool would create enough re-work to have justified writing from scratch? If tools aren't the devil, are there any besides j2py that can at least handle same-project import management? I don't expect any tool to match 3rd party libraries from one language to a substitute in another.

  Read the article

• Working with three dimensional data in an HTML (ASP.NET) table.

  - by ProfK

  I am working on the prototype for a scheduling application on an intranet system. The application is for scheduling and tracking promotional workers at various locations on various dates (hence location, date, workers dimensions). Currently, only for prototyping, I am generating a data table of location/date, and from this I iteratively build an HTML table (asp:Table control). On visiting each cell, I query for people working that location-date and populate the cell accordingly. This is very inefficiant, and will at worst be improved by querying cached data for the whole location/date grid. I'm looking around for established patterns and techniques for dealing with scenarios like this in HTML in general, maybe a visualisation library for jQuery or something, and for ASP.NET in particular, maybe a library for implementation on a GridView etc. Am I going in the right direction with this, and if so, what recomendations are there regarding the previous paragraph?

  Read the article

• character matching in grayscale image

  - by maximus

  I made patterns: images with the "A" letter of different sizes (from 12 to 72: 12, 14, .., 72) And I tested the method of pattern matching and it gave a good results. One way to select text regions from image is to run that algorithm for all small and big letters and digits of different sizes. And fonts! I don't like it. Instead of it I want to make something like a universal pattern or better to say: scanning image with different window sizes and select those regions where some function (probability of that there is a character at that window) is more than some fixed value. Do you know any methods or ideas to make that function? It must work with original image (grayscale).

  Read the article

• Mix and match class in C++/MFC

  - by Coder

  I'm trying to re-factor a code base, and there is some common functionality among unrelated classes that I'd love to unite. I would like to add that functionality in common base class, but I'm not sure if it's clean and good approach. Say I have CMyWnd class and CMyDialogEx class, both different, so they cannot inherit from one base class. I want to add a button to both classes and add the message handlers to both classes as well. So I'd like to do something like this: CMyWnd : public CWnd, public COnOkBtnFunctionality, public COnCancelBtnFunctionality CMyDialogEx: public CWnd, public COnOkBtnFunctionality Where COnOkBtnFunctionality would define CButton m_buttonOk, and all the afx_msg functions it should have. And so on. Is this approach doable/good? Or are there better patterns I should resort to?

  Read the article

• django-haystack urlpatterns include('haystack.urls') where does it lead to?

  - by Eugene

  I've recently begun to learn/install django/haystack/solr. Following the tutorial given in haystack site, I have urlpatterns = pattern('', r'^search/', include('haystack.urls')) I found haystack installed in /usr/local/lib/python2.6/dist-packages/haystack and located urls.py there. It has urlpatterns=patterns('haystack.views', url(r'^$', SearchView(), name='haystack_search'),) I thought the second argument of url() should be callable object. I looked at the views.py and SearchView is a class. What is going on here? What's get called eventually?

  Read the article

• Delegates vs. events in Cocoa

  - by aaronstacy

  I'm writing my first iPhone app, and I've been exploring the design patterns in Cocoa and Objective-C. I come from a background of client-side web development, so I'm trying to wrap my head around delegates. Specifically, I don't see why delegate objects are needed instead of event handlers. For instance, when the user presses a button, it is handled with an event (UITouchUpInside), but when the user finishes inputting to a text box and closes it with the 'Done' button, the action is handled by calling a method on the text box's delegate (textFieldShouldReturn). Why use a delegate method instead of an event? I also notice this in the view controller with the viewDidLoad method. Why not just use events?

  Read the article

• How can I avoid causing memory leaks in Firefox?

  - by mrdanimal

  It seems that there is a lot of information on memory leaks in IE and how web developers can avoid them, but I can't find much on avoiding leaks in FF. I've found lots of random tips on how end users can tweak their preferences, or tips for extension developers, but little on what I can do as a web developer to make sure my pages don't leak. Am I missing something? It seems lazy to just blame it on the user and say "you've got too many extensions". Or are the major patterns the same as in IE -- circular references and all that? Also, if anyone knows of any tools to troubleshoot leaks in FF, that would be great. I found this: https://addons.mozilla.org/en-US/firefox/addon/2490/ But it's apparently just for chrome and extension development.

  Read the article

• C# similar technologies and books in Java

  - by MigNix

  Hi, I know this can look like dublicate of other discussions and I have already reviewed them, but they are different. I want to learn Java and I want to know are there any books similar to those that I have seen for C#. Here is the list: C# 4.0 in a Nutshell: The Definitive Reference Probably Java in a Nutshell :) Professional C# 4.0 and .NET 4 Pro C# 2010 and the .NET 4 Platform Accelerated C# 2010 Programming WCF Services Essential Windows Communication Foundation (WCF): For .NET Framework 3.5 C# in Depth: What you need to master C# 2 and 3 CLR via C# Professional ADO.NET 3.5 with LINQ and the Entity Framework Professional Enterprise .NET Framework Design Guidelines: Conventions, Idioms, and Patterns for Reusable .NET Libraries Mainly I am interested in Java 6 and want to know about JVM , Cuncurency, Data access and distributed application technologies. I have seen there are some books on JVM like Inside the Java 2 Virtual Machine also some free books on official web site. Also I found concurrent programming in Java. But may be you can suggest any others. Thank you

  Read the article

• Is there an open source repository for SQL code?

  - by morpheous

  I find myself writing SQL code (queries or stored procs) to solve problems that can definitely be defined as 'patterns' that occur frequently in business. Rather than having to wrack my brain each time I encounter a new problem (which must have been solved a countless times by other coders/db analysts, I wondered if there was a repository I could go to check out (peer reviewed) code - and maybe add my two pence every now and then. I know different db vendors tend to write slightly variant forms of SQL - but there could still be a repository with ANSI stuff and proprietary stuff. Hopefully, such a site would encourage more people to write standardized SQL. Is there such a site?. If no - why not? (would anyone else be interested in such a site?) If such a site exists, please provide link(s), as Google is not finding anything remotely useful.

  Read the article

• Is the offical Sun Java EE tutorial the best way to learn how to make Java web apps?

  - by Nick

  I've been a web developer for almost a decade. I've mostly used classic ASP/JavaScript and I'd like to move into Java based apps. I have a decent understanding of Java itself (enough to know how to lookup what I don't know) and I spent some time doing minor work on a JSF/Spring/Hibernate app, but from what a trusted coworker told me, this application is the example of what not to do. I want to learn the really hardcore stuff (EJBs, HA Clustering, etc), but I know I have to walk before I can run. Is the Sun Tutorial the best place to start? Or is there an definitive book (like K&R for C or Gang of Four for design patterns) that I should buy?

  Read the article

• solutions for rapid front-end development?

  - by fayer

  im using mvc framework and i have learned some techniques that help me with different parts of RAD. models: doctrine/visual paradigm controllers/libraries: various design patterns now i only need to know what technique/solution i should use for the views so that i can create views more rapidly. cause i don't think it's efficient to code css/html manually, even though i understand it. its the same principle when using visual paradigm to create both my mysql database tables and doctrine model classes. i believe in using right tools will boost up development speed. so what could i use for the views to save time and energy and don't reinvent the wheel all the time? dreamweaver? any css generation tools? 960/blueprint for layout? suggestions? thanks

  Read the article

• Read Velocity Tokens/Tag from .vm file

  - by user1801660

  I have an application where in I am trying to create a velocity template repository which will help me centralise all my email templates and will allow me to create a communication hub. All templates will be called at runtime and populates with data via services. My problem is that I need to provide users with optional and compulsory params list when they define the template inputs for the velocity template. Is there a way to read the tokens/tags from the velocity template file and extract them?? Like I want a list of tokens $name.address.streetName to be available to me from .vm file. I do not want to go for Regex . I do not have to cache or reuse them , its just going to be a one time read and store the default,compulsory & optional params in the database. I am following these patterns : http://kickjava.com/src/org/apache/velocity/test/view/TemplateNodeView.java.htm How to use String as Velocity Template? Please advice.

  Read the article

• What algorithm would you use to code a parrot?

  - by Phil H

  A parrot learns the most commonly uttered words and phrases in its vicinity so it can repeat them at inappropriate moments. So how would you create a software version? Assuming it has access to a microphone and can record sound at will, how would you code it without requiring infinite resources? The best I can imagine is to divide the stream using silences in the sound, and then use some pattern recognition to encode each one as a list of tokens, storing new ones as you meet them. Hashing the token sequences and counting occurrences in a database, you could build up a picture of the most frequently uttered phrases. But given the huge variety in phrases, how do you prevent this just becoming a huge list? And the sheer number of pairs to match would surely generate lot of false positives from the combinatorial nature of matching. Would you use a neural net, since that's how a real parrot manages it? Or is there another, cleverer way of matching large-scale patterns in analogue data?

  Read the article

< Previous Page | 104 105 106 107 108 109 110 111 112 113 114 115  | Next Page >