Search Results

Search found 3618 results on 145 pages for 'huge'.

Page 124/145 | < Previous Page | 120 121 122 123 124 125 126 127 128 129 130 131  | Next Page >

• Could not laod file or assembly ‘System.Web.Silverlight’

  - by Adam Berent

  I really need some help with this as I have been trying to fix this for months and I can't figure it out. I run an online chess site written in Silverlight 3.0 The architecture is Silverlight Client connecting to a WCF service that reads and writes data to a SQL Server database. It is hosted on Godaddy, Once every so often I get the following error: Could not laod file or assembly ‘System.Web.Silverlight’ or one of its dependencies. The system cannot find the path specified. If I leave it alone it will fix itself after a few hours, however usually I just make a new publish of my application and it goes away. Also all the pages in the solution get this message not just the Silverlight application. So I have an aspx page with top ranks that does not use Silverlight but is in the same solution it also gets the same error. Its almost like the whole site dies. This does not seem like a huge issue but it makes going on vacation hard since my site can go down at any time I am away. Also this seems to happen the most when I am sleeping so I often don't get to fixing it until I have already lost hours of potential logins. If you have had the same issue please, please help!

  Read the article

• Serialization for memcached

  - by Ram

  I have this huge domain object(say parent) which contains other domain objects. It takes a lot of time to "create" this parent object by querying a DB (OK we are optimizing the DB). So we decided to cache it using memcached (with northscale to be specific) So I have gone through my code and marked all the classes (I think) as [Serializable], but when I add it to the cache, I see a Serialization Exception getting thrown in my VS.net output window. var cache = new NorthScaleClient("MyBucket"); cache.Store(StoreMode.Set, key, value); This is the exception: A first chance exception of type 'System.Runtime.Serialization.SerializationException' occurred in mscorlib.dll SO my guess is, I have not marked all classes as [Serializable]. I am not using any third party libraries and can mark any class as [Serializable], but how do I find out which class is failing when the cache is trying to serialize the object ? Edit1: casperOne comments make me think. I was able to cache these domain object with Microsoft Cache Application Block without marking them [Serializable], but not with NorthScale memcached. It makes me think that there might be something to do with their implementation, but just out of curiosity, am still interested in finding where it fails when trying to add the object to memcached

  Read the article

• Has inheritance become bad?

  - by mafutrct

  Personally, I think inheritance is a great tool, that, when applied reasonably, can greatly simplify code. However, I seems to me that many modern tools dislike inheritance. Let's take a simple example: Serialize a class to XML. As soon as inheritance is involved, this can easily turn into a mess. Especially if you're trying to serialize a derived class using the base class serializer. Sure, we can work around that. Something like a KnownType attribute and stuff. Besides being an itch in your code that you have to remember to update every time you add a derived class, that fails, too, if you receive a class from outside your scope that was not known at compile time. (Okay, in some cases you can still work around that, for instance using the NetDataContract serializer in .NET. Surely a certain advancement.) In any case, the basic principle still exists: Serialization and inheritance don't mix well. Considering the huge list of programming strategies that became possible and even common in the past decade, I feel tempted to say that inheritance should be avoided in areas that relate to serialization (in particular remoting and databases). Does that make sense? Or am messing things up? How do you handle inheritance and serialization?

  Read the article

• SQL: find entries in 1:n relation that don't comply with condition spanning multiple rows

  - by milianw

  I'm trying to optimize SQL queries in Akonadi and came across the following problem that is apparently not easy to solve with SQL, at least for me: Assume the following table structure (should work in SQLite, PostgreSQL, MySQL): CREATE TABLE a ( a_id INT PRIMARY KEY ); INSERT INTO a (a_id) VALUES (1), (2), (3), (4); CREATE TABLE b ( b_id INT PRIMARY KEY, a_id INT, name VARCHAR(255) NOT NULL ); INSERT INTO b (b_id, a_id, name) VALUES (1, 1, 'foo'), (2, 1, 'bar'), (3, 1, 'asdf'), (4, 2, 'foo'), (5, 2, 'bar'), (6, 3, 'foo'); Now my problem is to find entries in a that are missing name entries in table b. E.g. I need to make sure each entry in a has at least the name entries "foo" and "bar" in table b. Hence the query should return something similar to: a_id = 3 is missing name "bar" a_id = 4 is missing name "foo" and "bar" Since both tables are potentially huge in Akonadi, performance is of utmost importance. One solution in MySQL would be: SELECT a.a_id, CONCAT('|', GROUP_CONCAT(name ORDER BY NAME ASC SEPARATOR '|'), '|') as names FROM a LEFT JOIN b USING( a_id ) GROUP BY a.a_id HAVING names IS NULL OR names NOT LIKE '%|bar|foo|%'; I have yet to measure the performance tomorrow, but severly doubt it's any fast for tens of thousand of entries in a and thrice as many in b. Furthermore we want to support SQLite and PostgreSQL where to my knowledge the GROUP_CONCAT function is not available. Thanks, good night.

  Read the article

• .NET memory leak?

  - by SA

  I have an MDI which has a child form. The child form has a DataGridView in it. I load huge amount of data in the datagrid view. When I close the child form the disposing method is called in which I dispose the datagridview this.dataGrid.Dispose(); this.dataGrid = null; When I close the form the memory doesn't go down. I use the .NET memory profiler to track the memory usage. I see that the memory usage goes high when I initially load the data grid (as expected) and then becomes constant when the loading is complete. When I close the form it still remains constant. However when I take a snapshot of the memory using the memory profiler, it goes down to what it was before loading the file. Taking memory snapshot causes it to forcefully run garbage collector. What is going on? Is there a memory leak? Or do I need to run the garbage collector forcefully? More information: When I am closing the form I no longer need the information. That is why I am not holding a reference to the data.

  Read the article

• How important is it that models be consistent across project components?

  - by RonLugge

  I have a project with two components, a server-side component and a client-side component. For various reasons, the client-side device doesn't carry a fully copy of the database around. How important is it that my models have a 1:1 correlation between the two sides? And, to extend the question to my bigger concern, are there any time-bombs I'm going to run into down the line if they don't? I'm not talking about having different information on each side, but rather the way the information is encapsulated will vary. (Obviously, storage mechanisms will also vary) The server side will store each user, each review, each 'item' with seperate tables, and create links between them to gather data as necessary. The client side shouldn't have a complete user database, however, so rather than link against the user for gathering things like 'name', I'd store that on the review. In other words... --- Server Side --- Item: +id //Store stuff about the item User: +id +Name -Password Review: +id +itemId +rating +text +userId --- Device Side --- Item: +id +AverageRating Review: +id +rating +text +userId +name User: +id +Name //Stuff The basic idea is that certain 'critical' information gets moved one level 'up'. A user gets the list of 'items' relevant to their query, with certain review-orientation moved up (i. e. average rating). If they want more info, they query the detail view for the item, and the actual reviews get queried and added to the dataset (and displayed). If they query the actual review, the review gets queried and they pick up some additional user info along the way (maybe; I'm not sure if the user would have any use for any of the additional user information). My basic concern is that I don't wan't to glut the user's bandwidth or local storage with a huge variety of information that they just don't need, even if proper database normalizations suggests that information REALLY should be stored at a 'lower' level. I've phrased this as a fairly low-level conceptual issue because that's the level I'm trying to think / worry over, but if it matters I'm creating a PHP / MySQL server that provides data for a iOS / CoreData client.

  Read the article

• What are provenly scalable data persistence solutions for consumer profiles?

  - by Hubbard

  Consumer profiles with analytical scores [ConsumerID, 1..n demographical variables, 1...n analytical scores e.g. "likely to churn" "likely to buy an item 100$ in worth" etc.] have to be possible to query fast if they are to be used in customizing web-sites, consumer communications etc. Well. If you have: Large number of consumers Large profiles with a huge set of variables (as profiles describing human behaviour are likely to be..) ...you are in trouble. If you really have a physical relational database to which you target a query and then a physical disk starts to rotate someplace to give you an individual profile or a set of profiles, the profile user (a web site customizing a page, a recommendation engine making a recommendation..) has died of boredom before getting any observable results. There is the possibility of having the profiles in memory, which would of course increase the performance hugely. What are the most proven solutions for a fast-response, scalable consumer profile storage? Is there a shootout of these someplace?

  Read the article

• BitmapFactory.decodeFile out of memory with images 2400x2400

  - by alasarr

  I need to send an image from a file to a server. The server request the image in a resolution of 2400x2400. What I'm trying to do is: 1) Get a Bitmap using BitmapFactory.decodeFile using the correct inSampleSize. 2) Compress the image in JPEG with a quality of 40% 3) Encode the image in base64 4) Sent to the server I cannot achieve the first step, it throws an out of memory exception. I'm sure the inSampleSize is correct but I suppose even with inSampleSize the Bitmap is huge (around 30 MB in DDMS). Any ideas how can do it? Can I do these steps without created a bitmap object? I mean doing it on filesystem instead of RAM memory. This is the current code: // The following function calculate the correct inSampleSize Bitmap image = Util.decodeSampledBitmapFromFile(imagePath, width,height); // compressing the image ByteArrayOutputStream baos = new ByteArrayOutputStream(); image.compress(Bitmap.CompressFormat.JPEG, 40, baos); // encode image String encodedImage = Base64.encodeToString(baos.toByteArray(),Base64.DEFAULT));

  Read the article

• Is inheritance bad nowadays?

  - by mafutrct

  Personally, I think inheritance is a great tool, that, when applied reasonably, can greatly simplify code. However, I seems to me that many modern tools dislike inheritance. Let's take a simple example: Serialize a class to XML. As soon as inheritance is involved, this can easily turn into a mess. Especially if you're trying to serialize a derived class using the base class serializer. Sure, we can work around that. Something like a KnownType attribute and stuff. Besides being an itch in your code that you have to remember to update every time you add a derived class, that fails, too, if you receive a class from outside your scope that was not known at compile time. (Okay, in some cases you can still work around that, for instance using the NetDataContract serializer in .NET. Surely a certain advancement.) In any case, the basic principle still exists: Serialization and inheritance don't mix well. Considering the huge list of programming strategies that became possible and even common in the past decade, I feel tempted to say that inheritance should be avoided in areas that relate to serialization (in particular remoting and databases). Does that make sense? Or am messing things up? How do you handle inheritance and serialization?

  Read the article

• C#: How to implement a smart cache

  - by Svish

  I have some places where implementing some sort of cache might be useful. For example in cases of doing resource lookups based on custom strings, finding names of properties using reflection, or to have only one PropertyChangedEventArgs per property name. A simple example of the last one: public static class Cache { private static Dictionary<string, PropertyChangedEventArgs> cache; static Cache() { cache = new Dictionary<string, PropertyChangedEventArgs>(); } public static PropertyChangedEventArgs GetPropertyChangedEventArgsa(string propertyName) { if (cache.ContainsKey(propertyName)) return cache[propertyName]; return cache[propertyName] = new PropertyChangedEventArgs(propertyName); } } But, will this work well? For example if we had a whole load of different propertyNames, that would mean we would end up with a huge cache sitting there never being garbage collected or anything. I'm imagining if what is cached are larger values and if the application is a long-running one, this might end up as kind of a problem... or what do you think? How should a good cache be implemented? Is this one good enough for most purposes? Any examples of some nice cache implementations that are not too hard to understand or way too complex to implement?

  Read the article

• How to track a projects extraneous quirks

  - by Steerpike

  Hello, It's possible that the answer to this question may just be standard bug tracking software like jira or fogbugz, but I'm kind of hoping someone out there knows a better system for what I'm describing. My most current project is requiring a lot of setup quirkiness to get into a position where I can actually start a coding section. For example: A series of convoluted internal company commands before I can insitgate an SSH. Making sure any third party classes that make external calls have internal company proxy options setup - while also making sure these setting wont be set up when installed on a production environment Making sure the proxy is set before trying to install pear packages. Other similar things, mostly involving internal IT security and getting it to work with modules and packages. Individually none of these things is a huge deal, and I've written extensive notes to myself regarding exact commands and aditions I've made, but they're currently in a general text document and it's going to be hard to remember exactly where what I need is far down the line. We also have several new staff starting soon and I' rather give them an easier time of setting up their programming environments. Like I said, they aren't 'programming quirks' exactly, but just the constant fiddling that comes about before programming starts in earnest. Any thoughts on the best way to documents these things for my own and future generations sanity?

  Read the article

• Need help implementing this algorithm with map reduce(hadoop)

  - by Julia

  Hi all! i have algorithm that will go through a large data set read some text files and search for specific terms in those lines. I have it implemented in Java, but I didnt want to post code so that it doesnt look i am searching for someone to implement it for me, but it is true i really need a lot of help!!! This was not planned for my project, but data set turned out to be huge, so teacher told me I have to do it like this. I was reading about MapReduce and thaught that i first do the standard implementation and then it will be more/less easier to do it with mapreduce. But didnt happen, since algorithm is quite stupid and nothing special, and map reduce...i cant wrap my mind around it. So here is shortly pseudo code of my algorithm LIST termList (there is method that creates this list from lucene index) FOLDER topFolder INPUT topFolder IF it is folder and not empty list files (there are 30 sub folders inside) FOR EACH sub folder GET file "CheckedFile.txt" analyze(CheckedFile) ENDFOR END IF Method ANALYZE(CheckedFile) read CheckedFile WHILE CheckedFile has next line GET line FOR(loops through termList) GET third word from line IF third word = term from list append whole line to string buffer ENDIF ENDFOR END WHILE OUTPUT string buffer to file Also, as you can see, each time when "analyze" is called, new file has to be created, i understood that map reduce is difficult to write to many outputs??? I understand mapreduce intuition, and my example seems perfectly suited for mapreduce, but when it comes to do this, obviously I do not know enough and i am STUCK! Please please help.

  Read the article

• Invoking [SKProductsRequest start] hangs on iOS 4.0

  - by figelwump

  Encountering an issue with SKProductsRequest that is specific to iOS 4.0. The problematic code: - (void)requestProductData { NSSet *productIdentifiers = [NSSet setWithObjects:kLimitedDaysUpgradeProductId, kUnlimitedUpgradeProductId, nil]; self.productsRequest = [[SKProductsRequest alloc] initWithProductIdentifiers:productIdentifiers]; self.productsRequest.delegate = self; [self.productsRequest start]; } - (void)productsRequest:(SKProductsRequest *)request didReceiveResponse:(SKProductsResponse *)response { NSLog(@"didReceiveResponse"); } When [SKProductsRequest start] is invoked, the productsRequest:didReceiveResponse: delegate method is never invoked; further, the entire app hangs and is completely unresponsive to input. Obviously, this is a huge issue for our iOS 4.0 users as it not only breaks payments but makes the app completely unusable. Some other things to note: this only happens on iOS 4.0; iOS 4.2, 3.x are fine. Also: if the delegate is not set on the SKProductsRequest (i.e. comment out the line "self.productsRequest.delegate = self;"), the app doesn't hang (but of course in that case we have no way of getting the product info). Also, the problem still reproduces with everything stripped out of the productsRequest:didReceiveResponse: callback (that method never actually gets called). Finally, if the productIdentifiers NSSet object is initialized to an empty set, the hang doesn't occur. Has anybody else experienced this? Any ideas/thoughts on what could be going on here, and how we might be able to work around this?

  Read the article

• Strange Puzzle - Invalid memory access of location

  - by Rob Graeber

  The error message I'm getting consistently is: Invalid memory access of location 0x8 rip=0x10cf4ab28 What I'm doing is making a basic stock backtesting system, that is iterating huge arrays of stocks/historical data across various algorithms, using java + eclipse on the latest Mac Os X. I tracked down the code that seems to be causing it. A method that is used to get the massive arrays of data and is called thousands of times. Nothing is retained so I don't think there is a memory leak. However there seems to be a set limit of around 7000 times I can iterate over it before I get the memory error. The weird thing is that it works perfectly in debug mode. Does anyone know what debug mode does differently in Eclipse? Giving the jvm more memory doesn't help, and it appears to work fine using -xint. And again it works perfectly in debug mode. public static List<Stock> getStockArray(ExchangeType e){ List<Stock> stockArray = new ArrayList<Stock>(); if(e == ExchangeType.ALL){ stockArray.addAll(getStockArray(ExchangeType.NYSE)); stockArray.addAll(getStockArray(ExchangeType.NASDAQ)); }else if(e == ExchangeType.ETF){ stockArray.addAll(etfStockArray); }else if(e == ExchangeType.NYSE){ stockArray.addAll(nyseStockArray); }else if(e == ExchangeType.NASDAQ){ stockArray.addAll(nasdaqStockArray); } return stockArray; } A simple loop like this, iterated over 1000s of times, will cause the memory error. But not in debug mode. for (Stock stock : StockDatabase.getStockArray(ExchangeType.ETF)) { System.out.println(stock.symbol); }

  Read the article

• Creating a dictionary with list of lists in Python

  - by ghbhatt

  I have a huge file (with around 200k inputs). The inputs are in the form: A B C D B E F C A B D D I am reading this file and storing it in a list as follows: text = f.read().split('\n') This splits the file whenever it sees a new line. Hence text is like follows: [[A B C D] [B E F] [C A B D] [D]] I have to now store these values in a dictionary where the key values are the first element from each list. i.e the keys will be A, B, C, D. I am finding it difficult to enter the values as the remaining elements of the list. i.e the dictionary should look like: {A: B C D; B: E F; C: A B D; D: 0} I have done the following: inlinkDict = {} for doc in text: adoc= doc.split(' ') docid = adoc[0] inlinkDict[docid] = inlinkDict.get(docid,0) + {I do not understand what to put in here} Please help as to how should i add the values to my dictionary. It should be 0 if there are no elements in the list except for the one which will be the key value. Like in example for 0.

  Read the article

• iPhone app developed with SDK 4.2, requires backward compatibility with iOS 3.1.3 .. easy way?

  - by mrd3650

  I have built an iPhone app with SDK 4.2 however I know also want to make it compatible with iOS 3.1.3. First step was to set the Deployment Target to 3.1.3. It runs fine on the 3.2 Simulator but the app crashes at times since I'm using some methods which are not available in this early SDK. So my qestion is, is there a straight forward way to locate the offending methods/classes I'm using in my project which are not available in 3.1.3 ? (without manually going through each method call and consult with the docs for the SDK availability?) Thanks. UPDATE: I have executed the app on 3.1.3 and attempted to manually test each execution path with the hope of locating all exceptions. This was completed with some level of success. However, what if the application is huge? and there are lots of execution paths? There must be some tool for this scenario. Any thoughts are much appreciated.

  Read the article

• What is PHP like as a programming language?

  - by seanlinmt

  I am not really familiar with PHP, but I get the impression that it is like JavaScript (syntax-wise). What are the benefits of a dynamically typed language, when compared to a strongly typed language like C# or Java, and how would this help in the context of web development? What would make a dynamically typed language so attractive? Or, does the popularity of PHP have more to do with it being free? Okay, I think I better give a little more background to get more meaningful answers, because I am not wanting a flame war. I come from a C background, and when I moved into C# and Visual Studio. Having code completion, integration with an SQL database, huge existing class libraries and easy to access documentation, as well as new tools such as LINQ and ReSharper was like heaven. I didn't enjoy JavaScript before JQuery, but now I love it as well. Recently, I ported a PHP project over to C# and I used Zend to help me debug and understand more while porting - instead of maintaining two code streams. That also cut down on the cost of the server and maintenance. Getting into PHP would be nice. I think that Visual Studio has spoiled me - but again Eclipse is also equally spoiling. It would be nice to have an answer from someone who has experience developing both under PHP and .NET.

  Read the article

• How can I integrate advanced computations into a database field?

  - by ciclistadan

  My biological research involves the measurement of a cellular structure as it changes length throughout the course of observation (capturing images every minute for several hours). As my data sets have become larger I am trying to store them in an Access database, from which I would like to perform various queries about their changes in size. I know that the SELECT statement can incorporate some mathematical permutations, but I have been unable to incorporate many of my necessary calculations (probably due to my lack of knowledge). For example, one calculation involves determining the rate of change during specifically defined periods of growth. This calculation is entirely dependent on the raw data saved in the table, therefore I didn't this it would be appropriate to just calculate it in excel prior to entry into the field. So my question is, what would be the most appropriate method of performing this calculation. Should I attempt to string together a huge SELECT calculation in my QUERY, or is there a way to use another language (I know perl?) which can be called to populate the new query field? I'm not looking for someone to write the code, just where is it appropriate to incorporate each step. Also, I am currently using Office Access but would be interested in any mySQL answers as I may be moving to this platform at a later date. Thanks all!

  Read the article

• What's the steps for SQL optimization and changes without reflect live system ?

  - by Space Cracker

  we have a big portal that build using SharePoint 2007 , asp.net 3.5 , SQL Server 2005 .. many developers work in it since 01/2008 and we are now doing huge analysis for current SQL Databases [not share-point DB ] to optimize and enhance it. The main db have about 330 table and 1720 stored procedure (SP) created from 01/2008 till now Many table names / Columns is very long and we want to short it we found SP names is written in 25 format :( , some of them are very complex and also we want to rename many SP parameters need to be renamed one of the biggest table is Registered user table, that will be spitted in more than one table for some optimization, many columns name will be changed I searched for the way that i can rename table names ,columns and i found SQL refactor tool but i still trying it .. my questions : Is SQl Refactor is the best tool for renaming ? or is there any other one ? if i want to make it manually, is there any references or best practice for that ? How can i do such changes in fast and stable way .. i search for recommendations and case studies if exist ?

  Read the article

• How would I sort files to directories based on filenames?

  - by gnomed

  I have a huge number of files to sort all named in some terrible convention. Here are some examples: (4)_mr__mcloughlin____.txt 12__sir_john_farr____.txt (b)mr__chope____.txt dame_elaine_kellett-bowman____.txt dr__blackburn______.txt These names are supposed to be a different person (speaker) each. Someone in another IT department produced these from a ton of XML files using some script but the naming is unfathomably stupid as you can see. I need to sort literally tens of thousands of these files with multiple files of text for each person; each with something stupid making the filename different, be it more underscores or some random number. They need to be sorted by speaker. This would be easier with a script to do most of the work then I could just go back and merge folders that should be under the same name or whatever. There are a number of ways I was thinking about doing this. parse the names from each file and sort them into folders for each unique name. get a list of all the unique names from the filenames, then look through this simplified list of unique names for similar ones and ask me whether they are the same, and once it has determined this it will sort them all accordingly. I plan on using Perl, but I can try a new language if it's worth it. I'm not sure how to go about reading in each filename in a directory one at a time into a string for parsing into an actual name. I'm not completely sure how to parse with regex in perl either, but that might be googleable. For the sorting, I was just gonna use the shell command: `cp filename.txt /example/destination/filename.txt` but just cause that's all I know so it's easiest. I dont even have a pseudocode idea of what im going to do either so if someone knows the best sequence of actions, im all ears. I guess I am looking for a lot of help, I am open to any suggestions. Many many many thanks to anyone who can help. B.

  Read the article

• What choices do I have for a future in software development?

  - by user354892

  After graduating from college with a degree in mathematics and a minor in computer science, I took over a year to find my first programming job. I very much enjoy my work environment, but sometimes I feel like I'm not developing professionally as quickly as I am capable of. My company does mostly web programming. The project that I work on is basically a front-end for a SQL database. The entire project is (AFAIK) coded is VB.NET. I've been working on the back-end logic of the program. After some time on the job, we decided that designing web pages is not my cup of tea. It seems like the thing that I spend more time on than anything else is searching the web and SO for information about poorly documented .net and web APIs. This does not make me happy; is this normal for a programming job; I don't think it is. It really hit me the other day when i saw a question about math asked here and I didn't know the answer; I feel like my knowledge is going stale! I was previously almost hired by another company where they design graphic-intensive battle simulations for the military. I sometimes wonder what my life might be like if I had that job. I feel like my math and problem solving skills might have been a better fit at this other company. Within the wide field of software development, there are a number of directions in which to go as evidenced by the huge variety of topics discussed here on StackOverflow. I would like to feel like I'm going in the direction where I will make the most of my skills and have a satisfying career. Let me word this question as clearly as possible: given the wide breadth of the field of software development, how does it break down into sub-fields and what are the considerations for developing a software development career. I do not want to manage my career by default.

  Read the article

• Force calling the derived class implementation within a generic function in C#?

  - by Adam Hardy

  Ok so I'm currently working with a set of classes that I don't have control over in some pretty generic functions using these objects. Instead of writing literally tens of functions that essentially do the same thing for each class I decided to use a generic function instead. Now the classes I'm dealing with are a little weird in that the derived classes share many of the same properties but the base class that they are derived from doesn't. One such property example is .Parent which exists on a huge number of derived classes but not on the base class and it is this property that I need to use. For ease of understanding I've created a small example as follows: class StandardBaseClass {} // These are simulating the SMO objects class StandardDerivedClass : StandardBaseClass { public object Parent { get; set; } } static class Extensions { public static object GetParent(this StandardDerivedClass sdc) { return sdc.Parent; } public static object GetParent(this StandardBaseClass sbc) { throw new NotImplementedException("StandardBaseClass does not contain a property Parent"); } // This is the Generic function I'm trying to write and need the Parent property. public static void DoSomething<T>(T foo) where T : StandardBaseClass { object Parent = ((T)foo).GetParent(); } } In the above example calling DoSomething() will throw the NotImplemented Exception in the base class's implementation of GetParent(), even though I'm forcing the cast to T which is a StandardDerivedClass. This is contrary to other casting behaviour where by downcasting will force the use of the base class's implementation. I see this behaviour as a bug. Has anyone else out there encountered this?

  Read the article

• STLifying C++ classes

  - by shambulator

  I'm trying to write a class which contains several std::vectors as data members, and provides a subset of vector's interface to access them: class Mesh { public: private: std::vector<Vector3> positions; std::vector<Vector3> normals; // Several other members along the same lines }; The main thing you can do with a mesh is add positions, normals and other stuff to it. In order to allow an STL-like way of accessing a Mesh (add from arrays, other containers, etc.), I'm toying with the idea of adding methods like this: public: template<class InIter> void AddNormals(InIter first, InIter last); Problem is, from what I understand of templates, these methods will have to be defined in the header file (seems to make sense; without a concrete iterator type, the compiler doesn't know how to generate object code for the obvious implementation of this method). Is this actually a problem? My gut reaction is not to go around sticking huge chunks of code in header files, but my C++ is a little rusty with not much STL experience outside toy examples, and I'm not sure what "acceptable" C++ coding practice is on this. Is there a better way to expose this functionality while retaining an STL-like generic programming flavour? One way would be something like this: (end list) class RestrictedVector<T> { public: RestrictedVector(std::vector<T> wrapped) : wrapped(wrapped) {} template <class InIter> void Add(InIter first, InIter last) { std::copy(first, last, std::back_insert_iterator(wrapped)); } private: std::vector<T> wrapped; }; and then expose instances of these on Mesh instead, but that's starting to reek a little of overengineering :P Any advice is greatly appreciated!

  Read the article

• C++: Conceptual problem in designing an intepreter

  - by sub

  I'm programming an interpreter for an experimental programming language (educational, fun,...) So far, everything went well (Tokenizer & Parser), but I'm getting a huge problem with some of the data structures in the part that actually runs the tokenized and parsed code. My programming language basically has only two types, int and string, and they are represented as C++ strings (std class) and ints Here is a short version of the data structure that I use to pass values around: enum DataType { Null, Int, String } class Symbol { public: string identifier; DataType type; string stringValue; int intValue; } I can't use union because string doesn't allow me to. This structure above is beginning to give me a headache. I have to scatter code like this everywhere in order to make it work, it is beginning to grow unmaintainable: if( mySymbol.type == Int ) { mySymbol.intValue = 1234; } else { mySymbol.stringValue = "abcde"; } I use the Symbol data structure for variables, return values for functions and general representation of values in the programming language. Is there any better way to solve this? I hope so!

  Read the article

• Modifying Django's pre_save/post_save Data

  - by Rodrogo

  Hi, I'm having a hard time to grasp this post_save/pre_save signals from django. What happens is that my model has a field called status and when a entry to this model is added/saved, it's status must be changed accordingly with some condition. My model looks like this: class Ticket(models.Model): (...) status = models.CharField(max_length=1,choices=OFFERT_STATUS, default='O') And my signal handler, configured for pre_save: def ticket_handler(sender, **kwargs): ticket = kwargs['instance'] (...) if someOtherCondition: ticket.status = 'C' Now, what happens if I put aticket.save() just bellow this last line if statement is a huge iteration black hole, since this action calls the signal itself. And this problem happens in both pre_save and post_save. Well... I guess that the capability of altering a entry before (or even after) saving it is pretty common in django's universe. So, what I'm doing wrong here? Is the Signals the wrong approach or I'm missing something else here? Also, would it be possible to, once this pre_save/post_save function is triggered, to access another model's instance and change a specific row entry on that? Thanks

  Read the article

< Previous Page | 120 121 122 123 124 125 126 127 128 129 130 131  | Next Page >