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• Setting Nullable Integer to String Containing Nothing yields 0

  - by Brian MacKay

  I've been pulling my hair out over some unexpected behavior from nullable integers. If I set an Integer to Nothing, it becomes Nothing as expected. If I set an Integer? to a String that is Nothing, it becomes 0! Of course I get this whether I explicitly cast the String to Integer? or not. I realize I could work around this pretty easily but I want to know what I'm missing. Dim NullString As String = Nothing Dim NullableInt As Integer? = CType(NullString, Integer?) 'Expected NullableInt to be Nothing, but it's 0! NullableInt = Nothing 'This works -- NullableInt now contains Nothing. How is this EDIT: Previously I had my code up here so without the explicit conversion to 'Integer?' and everyone seemed to be fixated on that. I want to be clear that this is not an issue that would have been caught by Option Strict On -- check out the accepted answer. This is a quirk of the string-to-integer conversion rules which predate nullable types, but still impact them.

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• Database for managing large volumes of (system) metrics

  - by symcbean

  Hi, I'm looking at building a system for managing and reporting stats on web page performance. I'll be collecting a lot more stats than are available in the standard log formats (approx 20 metrics) but compared to most types of database applications, the base data structure will be very simple. My problem is that I'll be accumulating a lot of data - in the region of 100,000 records (i.e. sets of metrics) per hour. Of course, resources are very limited! So that its possible to sensibly interact with the data, I'd need to consolidate each metric into one minute bins, broken down by URL, then for anything more than 1 day old, consolidated into 10 minute bins, then at 1 week, hourly bins. At the front end, I want to provide a view (prefereably as plots) of the last hour of data, with the facility for users to drill up/down through defined hierarchies of URLs (which do not always map directly to the hierarchy expressed in the path of the URL) and to view different time frames. Rather than coding all this myself and using a relational database, I was wondering if there were tools available which would facilitate both the management of the data and the reporting. I had a look at Mondrian however I can't see from the documentation I've looked at whether it's possible to drop the more granular information while maintaining the consolidated views of the data. RRDTool looks promising in terms of managing the data consolidation, but seems to be rather limited in terms of querying the dataset as a multi-dimensional/relational database. What else whould I be looking at?

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• Sync two SqlExpress using NHibernate

  - by Christian

  Hello, I am creating a simple project management system which uses NHibernate for object storage. The underlying database is SQL express (at least currently for development). The client runs on either the desktop or laptop. I know I could use web-services and store the DB only on the desktop, but this would force the desktop to be available all the time. I am currently thinking about duplicating the DB, having two instances with "different data". To clarify, we are not talking about a productive app here, its a prototype. One way to achieve this very simple would be the following process: Client: Check if desktop DB is available (through web service) Client: If yes, use desktop storage, no problem here Client: If not, use own DB as storage Client: Poll desktop regulary, as soon as it comes on, sync Client: Switch to desktop storage ... Desktop: Do not attempt any DB operation before checking for required sync Desktop: If sync needed, do it... My question is now, how would you sync? Assume 4 or 5 types of objects, all have GUID as identifiers. Would you always manually "lazy load" all objects of a certain type and feed them to the DB. Would you always drop the whole desktop DB in case the client DB may be newer and out of sync? Again, I want to stress out, I am not assuming any conflicts or stale data, I basically just want to "copy the whole DB from the client". Would you use NHibernate for this? Or would you separate the copy process? When I think about it, my questions comes down to this: Is there any function from NHibernate: SyncDBs_SourceWins_(SourceDB, TargetDB) Thanks for help, Chris

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• Evaluating expressions using Visual Studio 2005 SDK rather than automation's Debugger::GetExpression

  - by brone

  I'm looking into writing an addin (or package, if necessary) for Visual Studio 2005 that needs watch window type functionality -- evaluation of expressions and examination of the types. The automation facilities provide Debugger::GetExpression, which is useful enough, but the information provided is a bit crude. From looking through the docs, it sounds like an IDebugExpressionContext2 would be more useful. With one of these it looks as if I can get more information from an expression -- detailed information about the type and any members and so on and so forth, without having everything come through as strings. I can't find any way of actually getting a IDebugExpressionContext2, though! IDebugProgramProvider2 sort of looks relevant, in that I could start with IDebugProgramProvider2::GetProviderProcessData and then slowly drill down until reaching something that can supply my expression context -- but I'll need to supply a port to this, and it's not clear how to retrieve the port corresponding to the current debug session. (Even if I tried every port, it's not obvious how to tell which port is the right one...) I'm becoming suspicious that this simply isn't a supported use case, but with any luck I've simply missed something crashingly obvious. Can anybody help?

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• Optimizing T-SQL where an array would be nice

  - by Polatrite

  Alright, first you'll need to grab a barf bag. I've been tasked with optimizing several old stored procedures in our database. This SP does the following: 1) cursor loops through a series of "buildings" 2) cursor loops through a week, Sunday-Saturday 3) has a huge set of IF blocks that are responsible for counting how many Objects of what Types are present in a given building Essentially what you'll see in this code block is that, if there are 5 objects of type #2, it will increment @Type_2_Objects_5 by 1. IF @Number_Type_1_Objects = 0 BEGIN SET @Type_1_Objects_0 = @Type_1_Objects_0 + 1 END IF @Number_Type_1_Objects = 1 BEGIN SET @Type_1_Objects_1 = @Type_1_Objects_1 + 1 END IF @Number_Type_1_Objects = 2 BEGIN SET @Type_1_Objects_2 = @Type_1_Objects_2 + 1 END IF @Number_Type_1_Objects = 3 BEGIN SET @Type_1_Objects_3 = @Type_1_Objects_3 + 1 END [... Objects_4 through Objects_20 for Type_1] IF @Number_Type_2_Objects = 0 BEGIN SET @Type_2_Objects_0 = @Type_2_Objects_0 + 1 END IF @Number_Type_2_Objects = 1 BEGIN SET @Type_2_Objects_1 = @Type_2_Objects_1 + 1 END IF @Number_Type_2_Objects = 2 BEGIN SET @Type_2_Objects_2 = @Type_2_Objects_2 + 1 END IF @Number_Type_2_Objects = 3 BEGIN SET @Type_2_Objects_3 = @Type_2_Objects_3 + 1 END [... Objects_4 through Objects_20 for Type_2] In addition to being extremely hacky (and limited to a quantity of 20 objects), it seems like a terrible way of handling this. In a traditional language, this could easily be solved with a 2-dimensional array... objects[type][quantity] += 1; I'm a T-SQL novice, but since writing stored procedures often uses a lot of temporary tables (which could essentially be a 2-dimensional array) I was wondering if someone could illuminate a better way of handling a situation like this with two dynamic pieces of data to store. Requested in comments: The columns are simply Number_Type_1_Objects, Number_Type_2_Objects, Number_Type_3_Objects, Number_Type_4_Objects, Number_Type_5_Objects, and CurrentDateTime. Each row in the table represents 5 minutes. The expected output is to figure out what percentage of time a given quantity of objects is present throughout each day. Sunday - Object Type 1 0 objects - 69 rows, 5:45, 34.85% 1 object - 85 rows, 7:05, 42.93% 2 objects - 44 rows, 3:40, 22.22% On Sunday, there were 0 objects of type 1 for 34.85% of the day. There was 1 object for 42.93% of the day, and 2 objects for 22.22% of the day. Repeat for each object type.

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• Are UTF16 (as used by for example wide-winapi functions) characters always 2 byte long?

  - by Cray

  Please clarify for me, how does UTF16 work? I am a little confused, considering these points: There is a static type in C++, WCHAR, which is 2 bytes long. (always 2 bytes long obvisouly) Most of msdn and some other documentation seem to have the assumptions that the characters are always 2 bytes long. This can just be my imagination, I can't come up with any particular examples, but it just seems that way. There are no "extra wide" functions or characters types widely used in C++ or windows, so I would assume that UTF16 is all that is ever needed. To my uncertain knowledge, unicode has a lot more characters than 65535, so they obvisouly don't have enough space in 2 bytes. UTF16 seems to be a bigger version of UTF8, and UTF8 characters can be of different lengths. So if a UTF16 character not always 2 bytes long, how long else could it be? 3 bytes? or only multiples of 2? And then for example if there is a winapi function that wants to know the size of a wide string in characters, and the string contains 2 characters which are each 4 bytes long, how is the size of that string in characters calculated? Is it 2 chars long or 4 chars long? (since it is 8 bytes long, and each WCHAR is 2 bytes)

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• What is the rationale to not allow overloading of C++ conversions operator with non-member function

  - by Vicente Botet Escriba

  C++0x has added explicit conversion operators, but they must always be defined as members of the Source class. The same applies to the assignment operator, it must be defined on the Target class. When the Source and Target classes of the needed conversion are independent of each other, neither the Source can define a conversion operator, neither the Target can define a constructor from a Source. Usually we get it by defining a specific function such as Target ConvertToTarget(Source& v); If C++0x allowed to overload conversion operator by non member functions we could for example define the conversion implicitly or explicitly between unrelated types. template < typename To, typename From > operator To(const From& val); For example we could specialize the conversion from chrono::time_point to posix_time::ptime as follows template < class Clock, class Duration> operator boost::posix_time::ptime( const boost::chrono::time_point<Clock, Duration>& from) { using namespace boost; typedef chrono::time_point<Clock, Duration> time_point_t; typedef chrono::nanoseconds duration_t; typedef duration_t::rep rep_t; rep_t d = chrono::duration_cast<duration_t>( from.time_since_epoch()).count(); rep_t sec = d/1000000000; rep_t nsec = d%1000000000; return posix_time::from_time_t(0)+ posix_time::seconds(static_cast<long>(sec))+ posix_time::nanoseconds(nsec); } And use the conversion as any other conversion. For a more complete description of the problem, see here or on my Boost.Conversion library.. So the question is: What is the rationale to non allow overloading of C++ conversions operator with non-member functions?

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• Importing data from third party datasource (open architecture design )

  - by mare

  How would you design an application (classes, interfaces in class library) in .NET when we have a fixed database design on our side and we need to support imports of data from third party data sources, which will most likely be in XML? For instance, let us say we have a Products table in our DB which has columns Id Title Description TaxLevel Price and on the other side we have for instance Products: ProductId ProdTitle Text BasicPrice Quantity. Currently I do it like this: Have the third party XML convert to classes and XSD's and then deserialize its contents into strong typed objects (what we get as a result of this process is classes like ThirdPartyProduct, ThirdPartyClassification, etc.). Then I have methods like this: InsertProduct(ThirdPartyProduct newproduct) I do not use interfaces at the moment but I would like them to. What I would like is implement something like public class Contoso_ProductSynchronization : ProductSynchronization InsertProduct(ContosoProduct p) where ProductSynchronization will be an interface or abstract class. There will most likely be many implementations of ProductSynchronization. I cannot hardcode the types - classes like ContosoProduct, NorthwindProduct might be created from the third party XML's (so preferably I would continue to use deserialization). Hopefully someone will understand what I'm trying to explain here. Just imagine you are the seller and you have numerous providers and each one uses their own proprietary XML format. I don't mind the development, which will of course be needed everytime new format appears, because it will only require 10-20 methods to be implemented, I just want the architecture to be open and support that.

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• Tokenizing numbers for a parser

  - by René Nyffenegger

  I am writing my first parser and have a few questions conerning the tokenizer. Basically, my tokenizer exposes a nextToken() function that is supposed to return the next token. These tokens are distinguished by a token-type. I think it would make sense to have the following token-types: SYMBOL (such as <, :=, ( and the like REMARK (or a comment) NUMBER IDENT (such as the name of a function or a variable) STRING (Something enclosed between "....") Now, do you think this makes sense? Also, I am struggling with the NUMBER token-type. Do you think it makes more sense to further split it up into a NUMBER and a FLOAT token-type? Without a FLOAT token-type, I'd receive NUMBER (eg 402), a SYMBOL (.) followed by another NUMBER (eg 203) if I were about to parse a float. Finally, what do you think makes more sense for the tokenizer to return when it encounters a -909? Should it return the SYMBOL - first, followed by the NUMBER 909 or should it return a NUMBER -909 right away?

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• Drupal: allowing users to sign up to content using a form

  - by james6848

  My apologies if this is a little broad, but I'm struggling to know where to start here! OK, so I have a Drupal site and I need users to be able to sign up for certain content, here is the workflow in detail: I need a form within a block consisting of the following elements: First Name (required) Last Name (required) Organisation (optional) Email Address (required) Then there will be a choice of content to sign up to (using checkboxes): Policy Bulletin Action News eBulletin (which only members can sign up to) Then the usual submit button of course! Upon submission, users will: 1) Be taken to a confirmation page, or 2) Be informed about incorrectly filled in fields, and/or the need to become a user to be able to sign up for the eBulletin. Users will then receive an email when new content of the type(s) they signed up to is created, along with a link to the node. There should be details about how to unsubscribe within this email. I have used the Subscriptions module in the past, but I am not sure if it is possible to use a sign-up form with it. Plus, there is the added complexity that one of the content types, eBulletin, is only available for site members. Like I say, I'm struggling to know where to start, and any ideas would be gratefully received!

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• SQLAlchemy Custom Type Which Contains Multiple Columns

  - by Kekoa

  I would like to represent a datatype as a single column in my model, but really the data will be stored in multiple columns in the database. I cannot find any good resources on how to do this in SQLAlchemy. I would like my model to look like this(this is a simplified example using geometry instead of my real problem which is harder to explain): class 3DLine(DeclarativeBase): start_point = Column(my.custom.3DPoint) end_point = Column(my.custom.3DPoint) This way I could assign an object with the (x, y, z) components of the point at once without setting them individually. If I had to separate each component, this could get ugly, especially if each class has several of these composite objects. I would combine the values into one encoded field except that I need to query each value separately at times. I was able to find out how to make custom types using a single column in the documentation. But there's no indication that I can map a single type to multiple columns. I suppose I could accomplish this by using a separate table, and each column would be a foreign key, but in my case I don't think it makes sense to have a one to one mapping for each point to a separate table, and this still does not give the ability to set the related values all at once.

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• Java Function Analysis

  - by khan

  Okay..I am a total Python guy and have very rarely worked with Java and its methods. The condition is that I have a got a Java function that I have to explain to my instructor and I have got no clue about how to do so..so if one of you can read this properly, kindly help me out in breaking it down and explaining it. Also, i need to find out any flaw in its operation (i.e. usage of loops, etc.) if there is any. Finally, what is the difference between 'string' and 'string[]' types? public static void search(String findfrom, String[] thething){ if(thething.length > 5){ System.err.println("The thing is quite long"); } else{ int[] rescount = new int[thething.length]; for(int i = 0; i < thething.length; i++){ String[] characs = findfrom.split("[ \"\'\t\n\b\f\r]", 0); for(int j = 0; j < characs.length; j++){ if(characs[j].compareTo(thething[i]) == 0){ rescount[i]++; } } } for (int j = 0; j < thething.length; j++) { System.out.println(thething[j] + ": " + rescount[j]); } } }

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• Generic validate input data via regex. Input error when match.count == 0

  - by Valamas

  Hi, I have a number of types of data fields on an input form, for example, a web page. Some fields are like, must be an email address, must be a number, must be a number between, must have certain characters. Basically, the list is undefinable. I wish to come up with a generic way of validating the data inputed. I thought I would use regex to validate the data. The fields which need validation would be related to a "regex expression" and a "regex error message" stating what the field should contain. My current mock up has that when the match count is zero, that would signify an error and to display the message. While still a white belt regex designer I have come to understand that in certain situations that it is difficult to write a regex which results in a match count of zero for every case. A complex regex case I looked for help on was Link Here. The forum post was a disaster because I confused people helping me. But one of the statements said that it was difficult to make a regex with a match count of zero meaning the input data was invalid; that the regex was very difficult to write that for. Does anyone have comments or suggestions on this generic validation system I am trying to create? thanks

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• Request for advice about class design, inheritance/aggregation

  - by Lasse V. Karlsen

  I have started writing my own WebDAV server class in .NET, and the first class I'm starting with is a WebDAVListener class, modelled after how the HttpListener class works. Since I don't want to reimplement the core http protocol handling, I will use HttpListener for all its worth, and thus I have a question. What would the suggested way be to handle this: Implement all the methods and properties found inside HttpListener, just changing the class types where it matters (ie. the GetContext + EndGetContext methods would return a different class for WebDAV contexts), and storing and using a HttpListener object internally Construct WebDAVListener by passing it a HttpListener class to use? Create a wrapper for HttpListener with an interface, and constrct WebDAVListener by passing it an object implementing this interface? If going the route of passing a HttpListener (disguised or otherwise) to the WebDAVListener, would you expose the underlying listener object through a property, or would you expect the program that used the class to keep a reference to the underlying HttpListener? Also, in this case, would you expose some of the methods of HttpListener through the WebDAVListener, like Start and Stop, or would you again expect the program that used it to keep the HttpListener reference around for all those things? My initial reaction tells me that I want a combination. For one thing, I would like my WebDAVListener class to look like a complete implementation, hiding the fact that there is a HttpListener object beneath it. On the other hand, I would like to build unit-tests without actually spinning up a networked server, so some kind of mocking ability would be nice to have as well, which suggests I would like the interface-wrapper way. One way I could solve this would be this: public WebDAVListener() : WebDAVListener(new HttpListenerWrapper()) { } public WebDAVListener(IHttpListenerWrapper listener) { } And then I would implement all the methods of HttpListener (at least all those that makes sense) in my own class, by mostly just chaining the call to the underlying HttpListener object. What do you think? Final question: If I go the way of the interface, assuming the interface maps 1-to-1 onto the HttpListener class, and written just to add support for mocking, is such an interface called a wrapper or an adapter?

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• Is it poor design to create objects that only execute code during the constructor?

  - by Curtix

  In my design I am using objects that evaluate a data record. The constructor is called with the data record and type of evaluation as parameters and then the constructor calls all of the object's code necessary to evaluate the record. This includes using the type of evaluation to find additional parameter-like data in a text file. There are in the neighborhood of 250 unique evaluation types that use the same or similar code and unique parameters coming from the text file. Some of these evaluations use different code so I benefit a lot from this model because I can use inheritance and polymorphism. Once the object is created there isn't any need to execute additional code on the object (at least for now) and it is used more like a struct; its kept on a list and 3 properties are used later. I think this design is the easiest to understand, code, and read. A logical alternative I guess would be using functions that return score structs, but you can't inherit from methods so it would make it kind of sloppy imo. I am using vb.net and these classes will be used in an asp.net web app as well as in a distributed app. thanks for your input

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• WCF data services (OData), query with inheritance limitation?

  - by Mathieu Hétu

  Project: WCF Data service using internally EF4 CTP5 Code-First approach. I configured entities with inheritance (TPH). See previous question on this topic: Previous question about multiple entities- same table The mapping works well, and unit test over EF4 confirms that queries runs smoothly. My entities looks like this: ContactBase (abstract) Customer (inherits from ContactBase), this entity has also several Navigation properties toward other entities Resource (inherits from ContactBase) I have configured a discriminator, so both Customer and Resource map to the same table. Again, everythings works fine on the Ef4 point of view (unit tests all greens!) However, when exposing this DBContext over WCF Data services, I get: - CustomerBases sets exposed (Customers and Resources sets seems hidden, is it by design?) - When I query over Odata on Customers, I get this error: Navigation Properties are not supported on derived entity types. Entity Set 'ContactBases' has a instance of type 'CodeFirstNamespace.Customer', which is an derived entity type and has navigation properties. Please remove all the navigation properties from type 'CodeFirstNamespace.Customer'. Stacktrace: at System.Data.Services.Serializers.SyndicationSerializer.WriteObjectProperties(IExpandedResult expanded, Object customObject, ResourceType resourceType, Uri absoluteUri, String relativeUri, SyndicationItem item, DictionaryContent content, EpmSourcePathSegment currentSourceRoot) at System.Data.Services.Serializers.SyndicationSerializer.WriteEntryElement(IExpandedResult expanded, Object element, ResourceType expectedType, Uri absoluteUri, String relativeUri, SyndicationItem target) at System.Data.Services.Serializers.SyndicationSerializer.<DeferredFeedItems>d__b.MoveNext() at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteItems(XmlWriter writer, IEnumerable`1 items, Uri feedBaseUri) at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteFeedTo(XmlWriter writer, SyndicationFeed feed, Boolean isSourceFeed) at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteFeed(XmlWriter writer) at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteTo(XmlWriter writer) at System.Data.Services.Serializers.SyndicationSerializer.WriteTopLevelElements(IExpandedResult expanded, IEnumerator elements, Boolean hasMoved) at System.Data.Services.Serializers.Serializer.WriteRequest(IEnumerator queryResults, Boolean hasMoved) at System.Data.Services.ResponseBodyWriter.Write(Stream stream) Seems like a limitation of WCF Data services... is it? Not much documentation can be found on the web about WCF Data services (OData) and inheritance specifications. How can I overpass this exception? I need these navigation properties on derived entities, and inheritance seems the only way to provide mapping of 2 entites on the same table with Ef4 CTP5... Any thoughts?

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• Need help tuning a SQL statement

  - by jeffself

  I've got a table that has two fields (custno and custno2) that need to be searched from a query. I didn't design this table, so don't scream at me. :-) I need to find all records where either the custno or custno2 matches the value returned from a query on the same table based on a titleno. In other words, the user types in 1234 for the titleno. My query searches the table to find the custno associated with the titleno. It also looks for the custno2 for that titleno. Then it needs to do a search on the same table for all other records that have either the custno or custno2 returned in the previous search in the custno or custno2 fields for those other records. Here is what I've come up with: SELECT BILLYR, BILLNO, TITLENO, VINID, TAXPAID, DUEDATE, DATEPIF, PROPDESC FROM TRCDBA.BILLSPAID WHERE CUSTNO IN (select custno from trcdba.billspaid where titleno = '1234' union select custno2 from trcdba.billspaid where titleno = '1234' and custno2 != '') OR CUSTNO2 IN (select custno from trcdba.billspaid where titleno = '1234' union select custno2 from trcdba.billspaid where titleno = '1234' and custno2 != '') The query takes about 5-10 seconds to return data. Can it be rewritten to work faster?

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• What are some commonly used source code check-in policies?

  - by rwmnau

  I'm curious what code review policies other development shops apply to their source code when it's checked into the source control repository. I'm setting up a TFS (Team Foundation) server, and I'd like to apply some check-in policies to start to stamp out bad practices. For example, I was thinking of starting with the following couple, so this is the kind of stuff I'm looking for: Prohibit empty "Catch" blocks. This would prevent applications from swallowing any exceptions without at least requiring a comment explaining why it's not necessary to do anything with the exception. Prohibit "Catch ex as Exception" generic exception handling. Instead, require code to catch specific types of exceptions and deal with them appropriately, instead of just building catch-all handling. Require a check-in comment. This one should be self-explanatory, though it seems that TFS (and most other source-control systems) don't require a comment by default. While these are just examples, they're where I'm thinking of starting, and while I'd like some additional examples of what's popular, I'm open to feedback on these. Also, though we're a mostly .NET shop, I imagine the popular policies are universal across languages and IDEs (we have some Java development and a few people who will use the repository develop with Eclipse).

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• How can I restore the "auto" values with for list-style-type in nested unordered lists with CSS?

  - by Michael

  By default, an unstyled set of nested <ul> lists looks like this (in Chrome, Firefox, and IE at least): The top level has a list-style-type of disc, the next level is circle, and subsequent levels are square. If I include a stylesheet that changes the list-style-type to none, is there a simple way to revert back to the "automatic bullet types" later in the document? (e.g., override with a subsequent CSS definition or JavaScript style change) Basically, I'm looking for something like list-style-type: auto; (which is apparently not valid and has no effect): <style type="text/css"> ul { list-style-type: none; } ul { list-style-type: auto; } /* Does not work */ </style> Setting the list-style-type back to disc changes every bullet in the list and I no longer see different bullets at different levels, so that doesn't work either. Is the only way to accomplish this by explicitly defining styles for every level? e.g.: <style type="text/css"> ul { list-style-type: disc; } ul ul { list-style-type: circle; } ul ul ul { list-style-type: square; } </style>

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• Delphi: How to avoid EIntOverflow underflow when subtracting?

  - by Ian Boyd

  Microsoft already says, in the documentation for GetTickCount, that you could never compare tick counts to check if an interval has passed. e.g.: Incorrect (pseudo-code): DWORD endTime = GetTickCount + 10000; //10 s from now ... if (GetTickCount > endTime) break; The above code is bad because it is suceptable to rollover of the tick counter. For example, assume that the clock is near the end of it's range: endTime = 0xfffffe00 + 10000 = 0x00002510; //9,488 decimal Then you perform your check: if (GetTickCount > endTime) Which is satisfied immediatly, since GetTickCount is larger than endTime: if (0xfffffe01 > 0x00002510) The solution Instead you should always subtract the two time intervals: DWORD startTime = GetTickCount; ... if (GetTickCount - startTime) > 10000 //if it's been 10 seconds break; Looking at the same math: if (GetTickCount - startTime) > 10000 if (0xfffffe01 - 0xfffffe00) > 10000 if (1 > 10000) Which is all well and good in C/C++, where the compiler behaves a certain way. But what about Delphi? But when i perform the same math in Delphi, with overflow checking on ({Q+}, {$OVERFLOWCHECKS ON}), the subtraction of the two tick counts generates an EIntOverflow exception when the TickCount rolls over: if (0x00000100 - 0xffffff00) > 10000 0x00000100 - 0xffffff00 = 0x00000200 What is the intended solution for this problem? Edit: i've tried to temporarily turn off OVERFLOWCHECKS: {$OVERFLOWCHECKS OFF}] delta = GetTickCount - startTime; {$OVERFLOWCHECKS ON} But the subtraction still throws an EIntOverflow exception. Is there a better solution, involving casts and larger intermediate variable types?

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• Get XML-RPC (Andorid - PHP) web service different params type

  - by Jovan

  Hi, I want to create XML-RPC web service for Andorid (client) - PHP (Server) communication I create XML-RPC PHP web service server using this tutorial: http://articles.sitepoint.com/article/own-web-service-php-xml-rpc/5 For andorid client web service I use this project: http://code.google.com/p/android-xmlrpc/ server and client communication is OK, but I have problem with getting params from andorid client to php server. From andorid client I send two params (first integer and second float number) Object[] params = { 3, 3.6f, }; method.call(params); , but I don't know how to handle this parameters in php server?? in php server there is some function , but with only one param ($news_id): function news_viewNewsItem ( $news_id ) { /* Define the query to fetch the news item */ $query = "SELECT * FROM kd_xmlrpc_news WHERE news_id = '" . $news_id . "'"; $sql = mysql_query ( $query ); if ( $result = mysql_fetch_array ( $sql ) ) { /* Extract the variables for sending in our server response */ $news_item['news_id'] = $result['news_id']; $news_item['date'] = XMLRPC_convert_timestamp_to_iso8601( mysql_datetime_to_timestamp( $result['date'] ) ); $news_item['title'] = $result['title']; $news_item['full_desc'] = $result['full_desc']; $news_item['author'] = $result['author']; /* Respond to the client with the news item */ XMLRPC_response(XMLRPC_prepare($news_item), KD_XMLRPC_USERAGENT); } else { /* If there was an error, respond with a fault code instead */ XMLRPC_error("1", "news_viewNewsItem() error: Unable to read news:" . mysql_error(), KD_XMLRPC_USERAGENT); } } In server.py file there is functions for every method but I dont know how to write in php server: def add(self, x, y): print print "input x=%s, y=%s" % (str(x), str(y)) sum = x + y print "output", sum print return sum Can some one help me with code , and tell me how to handle various types from client to server?? Thanks and Happy New Year

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• How can I build a generic dataset-handling Perl library?

  - by Pep.

  Hello, I want to build a generic Perl module for handling and analysing biomedical character separated datasets and which can, most certain, be used on any kind of datasets that contain a mixture of categorical (A,B,C,..) and continuous (1.2,3,881..) and identifier (XXX1,XXX2...). The plan is to have people initialize the module and then use some arguments to point to the data file(s), the place were the analysis reports should be placed and the structure of the data. By structure of data I mean which variable is in which place and its name/type. And this is where I need some enlightenment. I am baffled how to do this in a clean way. Obviously, having people create a simple schema file, be it XML or some other format would be the cleanest but maybe not all people enjoy doing something like this. The solutions I can think of are: Create a configuration file in XML or similar and with a prespecified format. Pass the information during initialization of the module. Use the first row of the data as headers and try to guess types (ouch) Surely there must be a "canonical" way of doing this that is also usable and efficient. Thanks p.

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• deleting object with template for int and object

  - by Yokhen

  Alright so Say I have a class with all its definition, bla bla bla... template <class DT> class Foo{ private: DT* _data; //other stuff; public: Foo(DT* data){ _data = data } virtual ~Foo(){ delete _data } //other methods }; And then I have in the main method: int main(){ int number = 12; Foo<anyRandomClass>* noPrimitiveDataObject = new Foo<anyRandomClass>(new anyRandomClass()); Foo<int>* intObject = new Foo<int>(number); delete noPrimitiveDataObject; //Everything goes just fine. delete intObject; //It messes up here, I think because primitive data types such as int are allocated in a different way. return 0; } My question is: What could I do to have both delete statements in the main method work just fine? P.S.: Although I have not actually compiled/tested this specific code, I have reviewed it extensively (as well as indented. You're welcome.), so if you find a mistake, please be nice. Thank you.

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• Best way to migrate export/import from SQL Server to oracle

  - by matao

  Hi guys! I'm faced with needing access for reporting to some data that lives in Oracle and other data that lives in a SQL Server 2000 database. For various reasons these live on different sides of a firewall. Now we're looking at doing an export/import from sql server to oracle and I'd like some advice on the best way to go about it... The procedure will need to be fully automated and run nightly, so that excludes using the SQL developer tools. I also can't make a live link between databases from our (oracle) side as the firewall is in the way. The data needs to be transformed in the process from a star schema to a de-normalised table ready for reporting. What I'm thinking about is writing a monster query for SQL Server (which I mostly have already) that will denormalise and read out the data from SQL Server into a flat file using the sql server equivalent of sqlplus as a scheduled task, dump into a Well Known Location, then on the oracle side have a cron job that copies down the file and loads it with sql loader and rebuilds indexes etc. This is all doable, but very manual. Is there one or a combination of FOSS or standard oracle/SQL Server tools that could automate this for me? the Irreducible complexity is the query on one side and building indexes on the other, but I would love to not have to write the CSV dumping detail or the SQL loader script, just say dump this view out to CSV on one side, and on the other truncate and insert into this table from CSV and not worry about mapping column names and all other arcane sqlldr voodoo... best practices? thoughts? comments? edit: I have about 50+ columns all of varying types and lengths in my dataset, which is why I'd prefer to not have to write out how to generate and map each single column...

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• Scala: Correcting type inference of representation type over if statement

  - by drhagen

  This is a follow-up to two questions on representation types, which are type parameters of a trait designed to represent the type underlying a bounded type member (or something like that). I've had success creating instances of classes, e.g ConcreteGarage, that have instances cars of bounded type members CarType. trait Garage { type CarType <: Car[CarType] def cars: Seq[CarType] def copy(cars: Seq[CarType]): Garage def refuel(car: CarType, fuel: CarType#FuelType): Garage = copy( cars.map { case `car` => car.refuel(fuel) case other => other }) } class ConcreteGarage[C <: Car[C]](val cars: Seq[C]) extends Garage { type CarType = C def copy(cars: Seq[C]) = new ConcreteGarage(cars) } trait Car[C <: Car[C]] { type FuelType <: Fuel def fuel: FuelType def copy(fuel: C#FuelType): C def refuel(fuel: C#FuelType): C = copy(fuel) } class Ferrari(val fuel: Benzin) extends Car[Ferrari] { type FuelType = Benzin def copy(fuel: Benzin) = new Ferrari(fuel) } class Mustang(val fuel: Benzin) extends Car[Mustang] { type FuelType = Benzin def copy(fuel: Benzin) = new Mustang(fuel) } trait Fuel case class Benzin() extends Fuel I can easily create instances of Cars like Ferraris and Mustangs and put them into a ConcreteGarage, as long as it's simple: val newFerrari = new Ferrari(Benzin()) val newMustang = new Mustang(Benzin()) val ferrariGarage = new ConcreteGarage(Seq(newFerrari)) val mustangGarage = new ConcreteGarage(Seq(newMustang)) However, if I merely return one or the other, based on a flag, and try to put the result into a garage, it fails: val likesFord = true val new_car = if (likesFord) newFerrari else newMustang val switchedGarage = new ConcreteGarage(Seq(new_car)) // Fails here The switch alone works fine, it is the call to ConcreteGarage constructor that fails with the rather mystical error: error: inferred type arguments [this.Car[_ >: this.Ferrari with this.Mustang <: this.Car[_ >: this.Ferrari with this.Mustang <: ScalaObject]{def fuel: this.Benzin; type FuelType<: this.Benzin}]{def fuel: this.Benzin; type FuelType<: this.Benzin}] do not conform to class ConcreteGarage's type parameter bounds [C <: this.Car[C]] val switchedGarage = new ConcreteGarage(Seq(new_car)) // Fails here ^ I have tried putting those magic [C <: Car[C]] representation type parameters everywhere, but without success in finding the magic spot.

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