Search Results

Search found 6569 results on 263 pages for 'specification pattern'.

Page 190/263 | < Previous Page | 186 187 188 189 190 191 192 193 194 195 196 197  | Next Page >

• Immutability of big objects

  - by Malax

  Hi StackOverflow! I have some big (more than 3 fields) Objects which can and should be immutable. Every time I run into that case i tend to create constructor abominations with long parameter lists. It doesn't feel right, is hard to use and readability suffers. It is even worse if the fields are some sort of collection type like lists. A simple addSibling(S s) would ease the object creation so much but renders the object mutable. What do you guys use in such cases? I'm on Scala and Java, but i think the problem is language agnostic as long as the language is object oriented. Solutions I can think of: "Constructor abominations with long parameter lists" The Builder Pattern Thanks for your input!

  Read the article

• How to determine whether a .NET exception is being handled?

  - by romkyns

  We're investigating a coding pattern in C# in which we'd like to use a "using" clause with a special class, whose Dispose() method does different things depending on whether the "using" body was exited normally or with an exception. To the best of my understanding, the CLR keeps track of the current exception being handled until it's been consumed by a "catch" handler. However it's not entirely clear whether this information is exposed in any way for the code to access. Do you know whether it is, and if so, how to access it? For example: using (var x = new MyObject()) { x.DoSomething(); x.DoMoreThings(); } class MyObject : IDisposable { public void Dispose() { if (ExceptionIsBeingHandled) Rollback(); else Commit(); } } This looks almost like System.Transactions.TransactionScope, except that success/failure is not determined by a call to x.Complete(), but rather based on whether the using body was exited normally.

  Read the article

• Problem with assigning elements of a class array to individual variables in MATLAB

  - by Marc

  This is a bit of a duplicate of this question, this question, and this question, however those solutions don't work, so I'm asking mine. I've got an array of locally defined classes and I'd like to assign it to multiple, individual variables. This pattern doesn't work: %a is 2x1 of MyClass temp = mat2cell(a); [x,y] = temp{:}; %throws: ??? Insufficient number of outputs from right hand side of equal sign to satisfy assignment. Because temp is a single cell, with my 2x1 array in one cell, rather than a 2x1 cell array with one element of each of my original array in one cell. Any ideas?

  Read the article

• Expand in linq not loading inner data collections from service.

  - by Kit

  I am seeing odd behavior with service queries! I am using MVVM pattern for a silverlight 3 app on 3.5 framework and Dataservices 1.5. The following code eager loads correctly the parent object and the child heirarchy perfectly IF and ONLY IF I am preloading the data. But I would like to fetch a different set of the parent object (and its child heirarchy) on different button clicks. What I am seeing is that on button click, only the parent object is retrieved, and the child heirarchy contains nothing. Any suggestions? Any ideas how to tackle this? Thanks all. The method: DataServiceQuery serviceQuery = (DataServiceQuery)(from m1 in dbEntities.gis_Region.Expand("gis_RegionValue/gis_Measure") where m1.RegionGuid == new Guid(regionGuid) select m1); serviceQuery.BeginExecute(GetRegionDetailAsyncResult, serviceQuery); The wired Async Result: DataServiceQuery query = (DataServiceQuery)result.AsyncState; gis_Region region = query.EndExecute(result).First();

  Read the article

• Random directions, with no repeat.. (Bad Description)

  - by Neurofluxation

  Hey there, So I'm knocking together a random pattern generation thing. My code so far: int permutes = 100; int y = 31; int x = 63; while (permutes > 0) { int rndTurn = random(1, 4); if (rndTurn == 1) { y = y - 1; } //go up if (rndTurn == 2) { y = y + 1; } //go down if (rndTurn == 3) { x = x - 1; } //go right if (rndTurn == 4) { x = x + 1; } //go left setP(x, y, 1); delay(250); } My question is, how would I go about getting the code to not go back on itself? e.g. The code says "Go Left" but the next loop through it says "Go Right", how can I stop this? NOTE: setP turns a specific pixel on. Cheers peoples!

  Read the article

• IIS7 301 Redirect from a List of URLs

  - by corymathews

  Recent changes are forcing me to add a bunch of 301 redirects. Seems that IIS7 is my best bet as compared to redirects within the files. I have found how to add them 1 by 1 but this requires the page/folder to exist (which most don't anymore(and creating them seems to defeat the point of the redirect)) and does not work on dynamic urls. I also cannot go to every page and add the redirects at the page level because some older pages are in php which is no longer supported on the new server. There is also no obvious pattern to the changes so each one must be made on its own. samples of the redirects page.htm - /page/ /folder/folder/ - /folder/folder.cfm /folder/folder/ - /folder/ /page.php?id=1 - page.htm

  Read the article

• Can you use data binding with the Content property of a WPF Frame?

  - by dthrasher

  I can use data binding to set the initial Content of a WPF Frame, but subsequent changes to the the bound property (implemented using INotifyPropertyChange) do not seem to change the content. Also, does anyone know if binding directly to the Content property in this way will cause the bound item to appear in the Frame or NavigationWindow's journal? Some context: I realize that I should probably be using the NavigationService to interact with the Frame, but I'm attempting to follow the MVVM pattern. It seems like it would be much simpler to databind to the Content property...

  Read the article

• C# Late Binding for Parameterized Property

  - by optim

  I'm trying to use late binding to connect to a COM automation API provided by a program called Amibroker, using a C# WinForms project. So far I've been able to connect to everything in the API except one item, which I believe to be a "parameterized property" based on extensive Googling. Here's what the API specification looks like according to the docs (Full version here: http://www.amibroker.com/guide/objects.html): Property Filter(ByVal nType As Integer, ByVal pszCategory As String) As Long [r/w] A javascript snippet to update the value looks like this: AB = new ActiveXObject("Broker.Application"); AA = AB.Analysis; AA.Filter( 0, "market" ) = 0; Using the following C# late-binding code, I can get the value of the property, but I can't for the life of me figure out how to set the value: object[] parameter = new object[2]; parameter[0] = Number; parameter[1] = Type; object filters = _analysis.GetType().InvokeMember("Filter", BindingFlags.GetProperty, null, _analysis, parameter); So far I have tried: using BindingFlags.SetProperty, BindingFlags.SetField casting the returned object to a PropertyInfo object and trying to update the value using it adding extra object containing the value to the parameters object various other things as last-ditch efforts From what I can see, this should be straight-forward, but I'm finding the late binding in C# to be cumbersome at best. The property looks like a method call to me, which is what is throwing me off. How does one assign a value to a method, and what would the prototype for late-binding C# code look like for it? Hopefully that explains it well enough, but feel free to ask if I've left anything unclear. Thanks in advance for any help! Daniel

  Read the article

• How do you parse the XDG/gnome/kde menu/desktop item structure in c++??

  - by Joe Soul-bringer

  I would like to parse the menu structure for Gnome Panels (the standard Gnome Desktop application launcher) and it's KDE equivalent using c/c++ function calls. That is, I'd like a list of what the base menu categories and submenu are installed in a given machine. I would like to do with using fairly simple c/c++ function calls (with NO shelling out please). I understand that these menus are in the standard xdg format. I understand that this menu structure is stored in xml files such as: /home/user/.config/menus/applications.menu I've look here: http://www.freedesktop.org/wiki/Specifications/menu-spec?action=show&redirect=Standards%2Fmenu-spec but all they offer is the standard and some shell files to insert item entries (I don't want shell scripts, I don't want installation, I definitely don't want to create a c-library from the XDG specification. I want to find the existing menu structure). I've looked here: http://library.gnome.org/admin/system-admin-guide/stable/menustructure-13.html.en for more notes on these structures. None of this gives me a good idea of how determine the menu structures using a c/c++ program. The actual gnome menu structures seem to be a horrifically hairy things - they don't seem to show the menu structure but to give an XML-coded description of all the changes that the menus have gone through since installation. I assume gnome panels parses these file so there's a function buried somewhere to do this but I've yet to find where that function is after scanning library.gnome.org for a couple of days. I've scanned the Nautilus source code as well but Panels seem to exist elsewhere or are burried well. Thanks in advance

  Read the article

• Is there any benefit to declaring a private property with a getter and setter?

  - by AmoebaMan17

  I am reviewing another developer's code and he has written a lot of code for class level variables that is similar to the following: /// <summary> /// how often to check for messages /// </summary> private int CheckForMessagesMilliSeconds { get; set; } /// <summary> /// application path /// </summary> private string AppPath { get; set; } Doesn't coding this way add unnecessary overhead since the variable is private? Am I not considering a situation where this pattern of coding is required for private variables?

  Read the article

• std::string insert method has ambiguous overloads?

  - by sdg

  Environment: VS2005 C++ using STLPort 5.1.4. Compiling the following code snippet: std::string copied = "asdf"; char ch = 's'; copied.insert(0,1,ch); I receive an error: Error 1 error C2668: 'stlpx_std::basic_string<_CharT,_Traits,_Alloc>::insert' : ambiguous call to overloaded function It appears that the problem is the insert method call on the string object. The two defined overloads are void insert ( iterator p, size_t n, char c ); string& insert ( size_t pos1, size_t n, char c ); But given that STLPort uses a simple char* as its iterator, the literal zero in the insert method in my code is ambiguous. So while I can easily overcome the problem by hinting such as copied.insert(size_t(0),1,ch); My question is: is this overloading and possible ambiguity intentional in the specification? Or more likely an unintended side-effect of the specific STLPort implementation? (Note that the Microsoft-supplied STL does not have this problem as it has a class for the iterator, instead of a naked pointer)

  Read the article

• Pass a captured named regular expression to URL dictionary in generic view

  - by Trent Jurewicz

  I am working with a generic view in Django. I want to capture a named group parameter in the URL and pass the value to the URL pattern dictionary. For example, in the URLConf below, I want to capture the parent_slug value in the URL and pass it to the queryset dictionary value like so: urlpatterns = patterns('django.views.generic.list_detail', (r'^(?P<parent_slugs>[-\w])$', 'object_list', {'queryset':Promotion.objects.filter(category=parent_slug)}, 'promo_promotion_list'), ) Is this possible to do in one URLConf entry, or would it be wiser if I create a custom view to capture the value and pass the queryset directly to the generic view from my overridden view?

  Read the article

• Inconsistent MySQL COLLATE errors across databases

  - by Teflon Ted

  I have two physically-separate MySQL databases on which I have to run a single query. The query has a section of SQL that looks like this: and foo_table.bar_column like concat('%', rules.pattern, '%') COLLATE utf8_general_ci It runs fine on database A but on database B I get this error: ERROR 1253 (42000): COLLATION 'utf8_general_ci' is not valid for CHARACTER SET 'latin1' If I remove the collation it runs fine on database B but on database A I get this error: ERROR 1267 (HY000): Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8_unicode_ci,IMPLICIT) for operation 'like' Is there a version of the query that will run on both databases? Or, is there a configuration I can change on either database to make the query happy in both places? Update: Database A is version 5.1.38, Database B is version 5.1.34

  Read the article

• GUI system architecture?

  - by topright

  I'm designing GUI (graphical user interface) system for a game engine (C++). Idea is to create a heirarchy of GUI controllers like Focusable, Hoverable, Dragable etc. Every GUI component can attach multiple controllers, they modify component's behaviour. I think it gives flexible system and protects from code duplication. Different instances of the same GUI class can have different complex behaviours (may be, even change it dynamically), so this approach looks practical. The other choice is to add focused, hovered, dragged etc. flags in the base GUI component class. It looks like overhead and not that flexible. Another solution is to use Decorator pattern and wrap objects with FocusDecorator, HoverDecorator etc. Maintaining such system looks a bit harder. Question: What are pitfalls in my solution? May be you have seen a better approaches in GUI systems? What are the best ways of implementing such flexible complex system?

  Read the article

• MVVM View reference to ViewModel

  - by BrettRobi

  I'm using MVVM in a WPF app. I'm very new to both. Let me state that I am not a purest in the MVVM pattern, I am trying to use as many best practices as I can but am trying to make what I think are reasonable compromises to make it work in our environment. For example, I am not trying to achieve 0% code in my View codebehind. I have a couple of questions about best practices. 1) I understand I don't want my VM to know about the attached View, but is it reasonable for the View to have a reference to its VM? 2) If a control in a View opens another View (such as a dialog) should I handle this in the View? It seems wrong to handle it in the VM since then the VM has some knowledge of a specific View.

  Read the article

• Regular expressions and matching URLs with metacharacters

  - by James P.

  I'm having trouble finding a regular expression that matches the following String. Korben;http://feeds.feedburner.com/KorbensBlog-UpgradeYourMind?format=xml;1 One problem is escaping the question mark. Java's pattern matcher doesn't seem to accept \? as a valid escape sequence but it also fails to work with the tester at myregexp.com. Here's what I have so far: ([a-zA-Z0-9])+;http://([a-zA-Z0-9./-]+);[0-9]+ Any suggestions? Edit: The original intent was to match all URLs that could be found after the first semi colon.

  Read the article

• Question about cloning in Java

  - by devoured elysium

  In Effective Java, the author states that: If a class implements Cloneable, Object's clone method returns a field-by-field copy of the object; otherwise it throws CloneNotSupportedException. What I'd like to know is what he means with field-by-field copy. Does it mean that if the class has X bytes in memory, it will just copy that piece of memory? If yes, then can I assume all value types of the original class will be copied to the new object? class Point { private int x; private int y; @Override public Point clone() { return (Point)super.clone(); } } If what Object.clone() does is a field by field copy of the Point class, I'd say that I wouldn't need to explicitly copy fields x and y, being that the code shown above will be more than enough to make a clone of the Point class. That is, the following bit of code is redundant: @Override public Point clone() { Point newObj = (Point)super.clone(); newObj.x = this.x; //redundant newObj.y = this.y; //redundant } Am I right? I know references of the cloned object will point automatically to where the original object's references pointed to, I'm just not sure what happens specifically with value types. If anyone could state clearly what Object.clone()'s algorithm specification is (in easy language) that'd be great. Thanks

  Read the article

• Rails: common approach for handling exceptions in restful actions on objects that have been destroye

  - by Greg

  It is very common in Rails for an objects_controller controller to have RESTful edit and destroy actions like so: def edit @object = Object.find(params[:id]) end def destroy @object = Object.find(params[:id]) @object.destroy redirect_to :back end With an associated view that provides edit and destroy links like so: <%= link_to "Edit the Object", edit_object_path(object) %> <%= link_to "Delete", object, :confirm => 'Are you sure?', :method => :delete %> And it is easy to blow this up. If I open two browser windows, A and B, destroy an object with the "Delete" link in browser A and then press the "Edit" link in browser B, the find() in the edit action throws an exception. Obviously there are several ways to deal with this in the edit action: catch the exception and recover gracefully use @object = find(:first, "conditions... etc. and test the @object before going further But seeing as this is such a common pattern, I would love to know how other folks deal with this situation.

  Read the article

• How should I implement items that are normalized in the Database, in Object Oriented Design?

  - by Jonas

  How should I implement items that are normalized in the Database, in Object Oriented classes? In the database I have a big table of items and a smaller of groups. Each item belong to one group. This is how my database design look like: +----------------------------------------+ | Inventory | +----+------+-------+----------+---------+ | Id | Name | Price | Quantity | GroupId | +----+------+-------+----------+---------+ | 43 | Box | 34.00 | 456 | 4 | | 56 | Ball | 56.50 | 3 | 6 | | 66 | Tin | 23.00 | 14 | 4 | +----+------+-------+----------+---------+ Totally 3000 lines +----------------------+ | Groups | +---------+------+-----+ | GroupId | Name | VAT | +---------+------+-----+ | 4 | Mini | 0.2 | | 6 | Big | 0.3 | +---------+------+-----+ Totally 10 lines I will use the OOP classes in a GUI, where the user can edit Items and Groups in the inventory. It should also be easy to do calculations with a bunch of items. The group information like VAT are needed for the calculations. I will write an Item class, but do I need a Group class? and if I need it, should I keep them in a global location or how do I access it when I need it for Item-calculations? Is there any design pattern for this case?

  Read the article

• Instanced drawing with OpenGL ES 2.0

  - by Mårten Wikström

  In short: Is it possible to use the gl_InstanceID built-in variable in OpenGL ES 2.0? And, if so, how? Some more info: I want to draw multiple instances of an object using glDrawArraysInstanced and gl_InstanceID, and I want my application to run on multiple platforms, including iOS. The specification clearly says that these features require ES 3.0. According to the iOS Device Compatibility Reference ES 3.0 is only available on a few devices (those based on the A7 GPU; so iPhone 5s, but not on iPhone 5 or earlier). So my first assumption was that I needed to avoid using instanced drawing on older iOS devices. However, further down in the compatibility reference document it says that the EXT_draw_instanced extension is supported for all SGX Series 5 processors (that includes iPhone 5 and 4s). This makes me think that I could indeed use instanced drawing on older iOS devices too, by looking up and using the appropriate extension function (EXT or ARB) for glDrawArraysInstanced. I'm currently just running some test code using SDL and GLEW on Windows so I haven't tested anything on iOS yet. However, in my current setup I'm having trouble using the gl_InstanceID built-in variable in a vertex shader. I'm getting the following error message: 'gl_InstanceID' : variable is not available in current GLSL version Enabling the "draw_instanced" extension in GLSL has no effect: #extension GL_ARB_draw_instanced : enable #extension GL_EXT_draw_instanced : enable The error goes away when I specifically declare that I need ES 3.0 (GLSL 300 ES): #version 300 es Although that seem to work fine on my Windows desktop machine in an ES 2.0 context I doubt that this would work on an iPhone 5. So, shall I abandon the idea of being able to use instanced drawing on older iOS devices?

  Read the article

• How to access File over the Network

  - by Polo

  Hi! I am having a hard time on this one, I have a folder over the network with public access (no credential restriction). I am trying to do a File.Exist or Directory.Exist and I keep on having a exception. Can someone tell me the good way to do IO over the network. EDIT 1 FOR DETAILS: if i do execture = \agoodip\Public\test.txt I get the file etc etc In my code it look like a basic Directory.Exist(@"\\agoodip\Public") or File.exist(@"\\agoodip\Public\test.txt") The exception I get is Path not found. EDIT 2 : I am using Silverlight 3, Is there any security pattern to be aware of to lookup file on the network? Thanks!

  Read the article

• Using Regex to remove Carriage Returns in a CSV file in Notepad++

  - by Barry

  I have a CSV file I need to clean up. This is a one-time thing so I'd like to do it in Notepad++ if possible. The CSV file has two fields, one of which is wrapped in quotes. I'd like to remove any Carriage Returns from within the quoted field. I was trying to use this pattern but can't get it quite right... (.*)\"(.*)\n(.*)\"(.*) Also correct me if I am wrong, but I presume the "replace with" value would be something along the lines of: \1\2\3\4 Thanks in advance. I'm also open to alternate solutions such as a quick and dirty PERL script.

  Read the article

• Django - Tips to avoid repeating code in views

  - by D Roddis

  I'm moving from a PHP background into Django development via python, mostly for the sake of tackling a MVC (or MVT) that I feel makes the most sense, although in this pattern I've started to notice a lot of repeated code in my views. For example, when logged in I have information regarding the user that I would like to appear on every page, although when using render_to_response and in every view this is required I have to grab the information and pass it to the render_to_response function. I'm wondering what would be the most efficient way to cut down on the duplicate code which would in essence be required in all views in a particular app. Thanks in advance.

  Read the article

• what happens to running/blocked runnables when executorservice is shutdown()

  - by prmatta

  I posted a question about a thread pattern today, and almost everyone suggested that I look into the ExecutorService. While I was looking into the ExecutorService, I think I am missing something. What happens if the service has a running or blocked threads, and someone calls ExecutorService.shutdown(). What happens to threads that are running or blocked? Does the ExecutorService wait for those threads to complete before it terminates? The reason I ask this is because a long time ago when I used to dabble in Java, they deprecated Thread.stop(), and I remember the right way of stopping a thread was to use sempahores and extend Thread when necessary: public void run () { while (!this.exit) { try { block(); //do something } catch (InterruptedException ie) { } } } public void stop () { this.exit = true; if (this.thread != null) { this.thread.interrupt(); this.thread = null; } } How does ExecutorService handle running threads?

  Read the article

• Why state cannot be part of Presenter in MVP?

  - by rFactor

  I read http://www.codeproject.com/KB/architecture/MVC_MVP_MVVM_design.aspx and it said: As powerful as they are, both MVC and MVP have their problems. One of them is persistence of the View’s state. For instance, if the Model, being a domain object, does not know anything about the UI, and the View does not implement any business logic, then where would we store the state of the View’s elements such as selected items? Fowler comes up with a solution in the form of a Presentation Model pattern. I wonder why Presenter can't hold View state? It already holds all View logic. As far as I understand, in MVC and MVP the state is kept in View. In PM and MVVM the state is kept in the Presentation Model. Why can't Presenter follow PM in this particular case and contain the state of the view? Here is another article which says Presenter does not hold View state, instead the view does: http://www.codeproject.com/KB/aspnet/ArchitectureComparison.aspx

  Read the article

< Previous Page | 186 187 188 189 190 191 192 193 194 195 196 197  | Next Page >