Search Results

Search found 9366 results on 375 pages for 'common lisp'.

Page 241/375 | < Previous Page | 237 238 239 240 241 242 243 244 245 246 247 248  | Next Page >

• Does anyone else think instance variables are problematic in database-backed applications?

  - by Ben Aston

  It occurs to me that state control in languages like C# is not well supported. By this, I mean, it is left upto the programmer to manage the state of in-memory objects. A common use-case is that instance variables in the domain-model are copies of information residing in persistent storage (i.e. the database). Clearly this violates the single point of authority principle, and "synchronisation" has to be managed by the developer. I envisage a system where instead of instance variables, we have simple public access/mutator methods marked with attributes that link them to the database, and where reads and writes are mediated by a framework that decides whether to hit the database. Does such a system exist? Am I completely missing the point, or is there some truth to this idea?

  Read the article

• Force an object to be allocated on the heap

  - by Warren Seine

  A C++ class I'm writing uses shared_from_this() to return a valid boost::shared_ptr<>. Besides, I don't want to manage memory for this kind of object. At the moment, I'm not restricting the way the user allocates the object, which causes an error if shared_from_this() is called on a stack-allocated object. I'd like to force the object to be allocated with new and managed by a smart pointer, no matter how the user declares it. I thought it could be done through a proxy or an overloaded new operator, but I can't find a proper way of doing that. Is there a common design pattern for such usage? If it's not possible, how can I test it at compile time?

  Read the article

• Persisting non-entity class that extends an entity (jpa) - example?

  - by Michal Minicki

  The JPA tutorial states that one can have a non-entity that extends entity class: Entities may extend both entity and non-entity classes, and non-entity classes may extend entity classes. - http://java.sun.com/javaee/5/docs/tutorial/doc/bnbqa.html Is it possible to persist such structure? I want to do this: @Entity abstract class Test { ... } class FirstConcreteTest extends Test { ... } // Non-ntity class SecondConcreteTest extends Test { ... } // Non-entity Test test = new FirstConcreteTest(); em.persist(test); What I would like it to do is to persist all fields mapped on abstract Test to a common database table for all concrete classes (first and second), leaving all fields of first and second test class unpersisted (these can contain stuff like EJBs, jdbc pools, etc). And a bonus question. Is it possible to persist abstract property too? @Entity abstract class Test { @Column @Access(AccessType.PROPERTY) abstract public String getName(); } class SecondConcreteTest extends Test { public String getName() { return "Second Concrete Test"; } }

  Read the article

• Accessing a webpage in C++

  - by wyatt

  Is there a good, simple library which allows C++ to load a webpage? I just want to grab the source as text. I'm not using any IDE or significant library, just straight command line. Tangentially, is there something fundamental I'm missing about programming in C++? I would think any language in common use today would have droves of web-based functionality, being so central to computer usage, but I can find next to no discussion on how to accomplish it. I realise C++ significantly predates the modern internet, so it lacking any core ability in the regard is reasonable, but the fact that relevant libraries seem so sparse is baffling. Thanks for your help.

  Read the article

• Parsing a string representing a float *with an exponent* in Python

  - by Lucas

  Hi, I have a large file with numbers in the form of 6,52353753563E-7. So there's an exponent in that string. float() dies on this. While I could write custom code to pre-process the string into something float() can eat, I'm looking for the pythonic way of converting these into a float (something like a format string passed somewhere). I must say I'm surprised float() can't handle strings with such an exponent, this is pretty common stuff. I'm using python 2.6, but 3.1 is an option if need be.

  Read the article

• How do I completely disable JavaScript errors using VS2008 and IE?

  - by TheHurt

  I am trying to prevent VS from breaking on JS errors. I have the following settings: In IE, under Tools-Internet Settings-Advanced (tab)-Browsing Disable script debugging (Internet Explorer) is checked. Disable script debugging (Other) is checked. In VS, under Debug-Exceptions-Common Language Runtime Exceptions JScript Exceptions (thrown and user-unhandled) are unchecked. In VS, under Tools-Options-Debugging-Just-In-Time Script is unchecked. There are some JavaScript errors that I just don't care about and it is driving me insane having to deal with them.

  Read the article

• Please help me to resolve my ajax error

  - by Rajesh Rolen- DotNet Developer

  i am using asp.net (.net framework 2.0) i am getting below error for my ajax popup extender error : Sys.WebForms.PageRequestManagerParserErrorException: The message received from the server could not be parsed. Common causes for this error are when the response is modified by calls to Response.Write(), response filters, HttpModules, or server trace is enabled. Details: Error parsing near 'The server rejected '. actually is not giving me error on localhost, i have uploaded it on 2 other different server on 1 server its working fine but on other server its giving me above error. (on server where is working fine has got windows 2000 and on which its giving error its ms windows 2003). this is link where its giving me error : highschoolers its on "Join new for free" button ..

  Read the article

• C# private (hidden) base class

  - by Loadmaster

  It is possible to make a C# base class accessible only within the library assembly it's compiled into, while making other subclasses that inherit from it public? For example: using System.IO; class BaseOutput: Stream // Hidden base class { protected BaseOutput(Stream o) { ... } ...lots of common methods... } public class MyOutput: BaseOutput // Public subclass { public BaseOutput(Stream o): base(o) { ... } public override int Write(int b) { ... } } Here I'd like the BaseOutput class to be inaccessible to clients of my library, but allow the subclass MyOutput to be completely public. I know that C# does not allow base classes to have more restrictive access than subclasses, but is there some other legal way of achieving the same effect?

  Read the article

• Suppress error with @ operator in PHP

  - by Mez

  In your opinion, is it ever valid to use the @ operator to suppress an error/warning in PHP whereas you may be handling the error? If so, in what circumstances would you use this? Code examples are welcome. Edit: Note to repliers. I'm not looking to turn error reporting off, but, for example, common practice is to use @fopen($file); and then check afterwards... but you can get rid of the @ by doing if (file_exists($file)) { fopen($file); } else { die('File not found'); } or similar. I guess the question is - is there anywhere that @ HAS to be used to supress an error, that CANNOT be handled in any other manner?

  Read the article

• Backbone inheritance - deep copying

  - by Ed .

  I've seen this question regarding inheritance in Backbone: Backbone.js view inheritance. Useful but doesn't answer my question. The problem I'm experiencing is this: Say I have a class Panel (model in this example); var Panel = Backbone.Model.extend({ defaults : { name : 'my-panel' } }); And then an AdvancedPanel; var AdvancedPanel = Panel.extend({ defaults : { label : 'Click to edit' } }); The following doesn't work: var advancedPanel = new AdvancedPanel(); alert(advancedPanel.get('name')); // Undefined :( JSFiddle here: http://jsfiddle.net/hWmnb/ I guess I can see that I can achieve this myself through some custom extend function that creates a deep copy of the prototype, but this seems like a common thing that people might want from Backbone inheritance, is there a standard way of doing it?

  Read the article

• how to access a label form user control in Parent class ?

  - by haansi

  I have a class UserControlBase that inherits System.Web.UI.UserControl and my user controls inherit UserControlBase class. UserControlBase has some common functions that are used in all user controls. I want to put error display funtion to UserControlBase as well so that I may not have to declare and manage it in all user controls. Error will be displayed in some label in usercontrol. Issue is how to access label which is in usercontrol in UserControlBase in function ? I dont want to pass label as argument. Please guide me on this issue. thanks

  Read the article

• Focus stealing is evil.

  - by lunixbochs

  A quick Google search for solutions to Focus Stealing in Windows reveals two main result categories: People suggesting incomplete solutions involving the ForegroundLockTimeout registry entry (or TweakUI, which I believe simply changes the aforementioned registry entry), which isn't very effective. Incessant hordes of Windows users complaining about it. It's particularly annoying in two common scenarios: Something triggers a program to popup a dialog window in the background while a fullscreen app is focused, causing the fullscreen app to minimize. A window steals focus while you are typing, stealing all of your keystrokes. If you happen to press Space, Enter, or trigger a keyboard shortcut (like Y for Yes), it can cause completely undesirable outcomes. What creative solutions can be applied to fix this problem for either or both of these scenarios?

  Read the article

• javasrcipt asyncronous function

  - by Ben

  Hi there, i have a problem understanding how this could/should be solved. I have two functions. In the first function ( I call it loadData() ) I'm doing an asyncronous request to the server to load some data. In the second function ( saveData() ) I'm also doing an asyn request to the server to write some data. In the callback of this request I'm callin loadData() to refresh the data. Now the problem: In the saveData() function I want to wait for loadData() to be finished bevore I show a dialog (like alert('Data saved')) I guess this is a common problem, but I couldn't find the solution for it (if there is one..) A solution would be to make the requests syncronous, but the framework I'm using doesn't offer that and I hope there's a better solution.. Thanks to all!

  Read the article

• IE6 and IE7 Standalone: What do they render differently?

  - by yar

  It's common knowledge on SO (see this question) that to run IE6 and IE7 you need a Windows box (or virtual box) with only those apps installed. I doubt this is true (they are the real versions, I think). The two browsers I'm interested in are: Standalone IE6 from the MultipleIEs install Standalone IE7 also from Tredosoft (but published elsewhere) These two plus a "real" install of IE8 give you three IE versions in one Windows install. We all know that "You're out of luck if you're trying to run them all reliably in one VM," but can someone please show me JS, CSS, or HTML (or a plugin, etc.) that does not work on the standalone versions as it should? Downvoters: I'm fixing the question so that it's less aggressive, but since there are no comments I don't know what you don't like about this question. Also: I have ALL the test cases set up (IE6, IE7 and IE8, as well as the standalone versions) so if anybody has any code they want me to test, I can do that.

  Read the article

• How do I use google API within perl CGI script?

  - by stephenmm

  The google API example shows that you should have the javascript within the head tag but I am using perl module CGI and in there they suggest that you use "print header;" instead of writting out your headers explicitly. So if I want to use the perl CGI module and the google API javascript what is the correct way to do this? I tried writing out the header explicitly but It seemed like the perl module really wanted me to use the header method. It seems like this would be a common use case but I looked around the web for some examples of this and I could not find one. Any help would be appreciated.

  Read the article

• WPF> Using RadioButtonList style. I want to display user friendly enum strings. how?

  - by Saghar

  Hi WPF lovers, I want to display all the possible enum values as Radio buttons. I am using popular RadioButtonList style to display the radiobutton from my enum using DataProvider in a Listcontrol. I can get all the radio buttons but the text appear with the radio button is not user friendly. I am using the following method. http://social.msdn.microsoft.com/forums/en-US/wpf/thread/5137aabc-bb3a-478a-9438-bc93dd9cc0ac/ I want to show "A ball" instead of "a" and "B ball" instead of "b" I thought about using converter. But where to use convert. Or any other way to display user friendly values? As this style is very common, thats why I am not writing whole code. If anything not clear, please ask. I have already invested about 5 hours on this problem.

  Read the article

• Caching result of SELECT statement for reuse in multiple queries

  - by Andrew

  I have a reasonably complex query to extract the Id field of the results I am interested in based on parameters entered by the user. After extracting the relevant Ids I am using the resulting set of Ids several times, in separate queries, to extract the actual output record sets I want (by joining to other tables, using aggregate functions, etc). I would like to avoid running the initial query separately for every set of results I want to return. I imagine my situation is a common pattern so I am interested in what the best approach is. The database is in MS SQL Server and I am using .NET 3.5.

  Read the article

• What is the role of asserts in C++ programs that have unit tests?

  - by lhumongous

  Greetings, I've been adding unit tests to some legacy C++ code, and I've run into many scenarios where an assert inside a function will get tripped during a unit test run. A common idiom that I've run across is functions that take pointer arguments and immediately assert if the argument is NULL. I could easily get around this by disabling asserts when I'm unit testing. But I'm starting to wonder if unit tests are supposed to alleviate the need for runtime asserts. Is this a correct assessment? Are unit tests supposed to replace runtime asserts by happening sooner in the pipeline (ie: the error is caught in a failing test instead of when the program is running). On the other hand, I don't like adding soft fails to code (eg: if(param == NULL) return false;). A runtime assert at least makes it easier to debug a problem in case a unit test missed a bug. Thanks!

  Read the article

• Java: stopping long HTTP operations

  - by kilonet

  I'm using Apache Common library for HTTP operations: HttpClient client = getClient(); PutMethod put = new PutMethod(url); FileRequestEntity countingFileRequestEntity = new FileRequestEntity(file, "application/octet-stream"); put.setRequestEntity(countingFileRequestEntity); client.executeMethod(put); put.releaseConnection(); I wonder how can safely interrup long HTTP operation. Running it in new thread and stopping it seems to be wrong way. HttpMethodBase has abort() method, but I can't understand how to use it because client.executeMethod blocks execution until it complets

  Read the article

• How do I conditionally assign ruby variables to javascript variables?

  - by Tony

  I have a website where I need a javascript version of the "current user" object along with the ruby version. I have been assigning these variables doing something like this... Application Controller: def get_user begin @current_user = User.find(session[:user_id]) if session[:user_id] @current_user_json = @current_user.to_json rescue session.delete(:user_id) @current_user = nil @current_user_json = {} end end Web Page: var current_user = null; current_user_json = '<%= @current_user_json %>'; if(current_user_json != ''){ current_user = current_user_json.user; } Even when there is a current user, I get the current user is undefined. Probably because I am putting the current_user_json assignment around single quotes. However, if I don't put it around single quotes, I'll always get a javascript error when no user is logged in because the syntax is invalid - current_user_json = ; I think I am just looking at this completely wrong and there must be a better way. Given that this is probably a common thing to do, I wanted to get other people's opinion on how to create an object in javascript that is a duplicate of the ruby object.

  Read the article

• Adding fields to a proxied class in Clojure

  - by mikera

  I'm using "proxy" to extend various Swing classes in a Clojure GUI application, generally with code that looks something like: (def ^JPanel mypanel (proxy [JPanel] [] (paintComponent [#^Graphics g] (.drawImage g background-image 0 0 nil)))) This works well but I can't figure out how to add additional fields to the newly extended class, for example making the background-image a field that could be subsequently updated. This would be pretty easy and common practice in Java. Is there a good way to do this in Clojure? Or is there another preferred method to achieve the same effect?

  Read the article

• Using C++ is a Linked-List implementation without using pointers possible or not?

  - by sonicoder

  My question is very simply, can one using C++, implment a link-list data structure without using pointers (next nodes)? To further qualify my question, I'm mean can one create a Linked-List data structure using only class instantiations. A common node definition might be like so: template<typename T> struct node { T t; node<T>* next; node<T>* prev; }; I'm aware of std::list etc, I'm just curious to know if its possible or not - and if so how? code examples will be greatly appreciated.

  Read the article

• Sharing a fabfile across multiple projects

  - by Matthew Rankin

  Fabric has become my deployment tool of choice both for deploying Django projects and for initially configuring Ubuntu slices. However, my current workflow with Fabric isn't very DRY, as I find myself: copying the fabfile.py from one Django project to another and modifying the fabfile.py as needed for each project (e.g., changing the webserver_restart task from Apache to Nginx, configuring the host and SSH port, etc.). One advantage of this workflow is that the fabfile.py becomes part of my Git repository, so between the fabfile.py and the pip requirements.txt, I have a recreateable virtualenv and deployment process. I want to keep this advantage, while becoming more DRY. It seems that I could improve my workflow by: being able to pip install the common tasks defined in the fabfile.py and having a fab_config file containing the host configuration information for each project and overriding any tasks as needed Any recommendations on how to increase the DRYness of my Fabric workflow?

  Read the article

• How can I load a SQLITE database from a buffer with the C API ?

  - by rockeye

  Hello, I am trying to load a database from the memory instead of opening a .sqlite file. I have read the C/C++ API reference but I can not find the proper method. The buffer I am trying to load is simply an sqlite file loaded in memory. I just want to use this buffer (a const char* array) without using the filesystem (I could have saved this buffer in a file, then load the file, but no). First, I create a memory DB : mErrorCode = sqlite3_open_v2(":memory:", &mSqlDatabase, lMode, NULL); This returns SQLITE_OK, then I tried to use the buffer as a statement and call preparev2(MyDB, MyBufferData, MyBufferLength, MyStatement, NULL) but it's not really a statement, and it returns an error. Same result if I call directly exec(MyDB, MyBufferData, NULL, NULL, NULL); I guess there is an appropriate method to achieve this as it might be common to load a DB from a stream or from decrypted data... Thanks.

  Read the article

• Print a file skipping X lines in Bash

  - by Eduardo

  Hi I have a very long file which I want to print but skipping the first 1e6 lines for example. I look into the cat man page but I did not see nay option to do this. I am looking for a command to do this or a simple bash program. I know how to do it using a program in C but I want to do it using the common commands. Any way to do it? Thanks a lot in advance..

  Read the article

< Previous Page | 237 238 239 240 241 242 243 244 245 246 247 248  | Next Page >