Search Results

Search found 11923 results on 477 pages for 'inner classes'.

Page 76/477 | < Previous Page | 72 73 74 75 76 77 78 79 80 81 82 83  | Next Page >

• Migrating from SQL Trace to Extended Events

  - by extended_events

  In SQL Server codenamed “Denali” we are moving our diagnostic tracing capabilities forward by building a system on top of Extended Events. With every new system you face the specter of migration which is always a bit of a hassle. I’m obviously motivated to see everyone move their diagnostic tracing systems over to the new extended events based system, so I wanted to make sure we lowered the bar for the migration process to help ease your trials. In my initial post on Denali CTP 1 I described a couple tables that we created that will help map the existing SQL Trace Event Classes to the equivalent Extended Events events. In this post I’ll describe the tables in a bit more details, explain the relationship between the SQL Trace objects (Event Class & Column) and Extended Event objects (Events & Actions) and at the end provide some sample code for a managed stored procedure that will take an existing SQL Trace session (eg. a trace that you can see in sys.Traces) and converts it into event session DDL. Can you relate? In some ways, SQL Trace and Extended Events is kind of like the Standard and Metric measuring systems in the United States. If you spend too much time trying to figure out how to convert between the two it will probably make your head hurt. It’s often better to just use the new system without trying to translate between the two. That said, people like to relate new things to the things they’re comfortable with, so, with some trepidation, I will now explain how these two systems are related to each other. First, some terms… SQL Trace is made up of Event Classes and Columns. The Event Class occurs as the result of some activity in the database engine, for example, SQL:Batch Completed fires when a batch has completed executing on the server. Each Event Class can have any number of Columns associated with it and those Columns contain the data that is interesting about the Event Class, such as the duration or database name. In Extended Events we have objects named Events, EventData field and Actions. The Event (some people call this an xEvent but I’ll stick with Event) is equivalent to the Event Class in SQL Trace since it is the thing that occurs as the result of some activity taking place in the server. An  EventData field (from now on I’ll just refer to these as fields) is a piece of information that is highly correlated with the event and is always included as part of the schema of an Event. An Action is something that can be associated with any Event and it will cause some additional “action” to occur when ever the parent Event occurs. Actions can do a number of different things for example, there are Actions that collect additional data and, take memory dumps. When mapping SQL Trace onto Extended Events, Columns are covered by a combination of both fields and Actions. Knowing exactly where a Column is covered by a field and where it is covered by an Action is a bit of an art, so we created the mapping tables to make you an Artist without the years of practice. Let me draw you a map. Event Mapping The table dbo.trace_xe_event_map exists in the master database with the following structure: Column_name Type trace_event_id smallint package_name nvarchar xe_event_name nvarchar By joining this table sys.trace_events using trace_event_id and to the sys.dm_xe_objects using xe_event_name you can get a fair amount of information about how Event Classes are related to Events. The most basic query this lends itself to is to match an Event Class with the corresponding Event. SELECT     t.trace_event_id,     t.name [event_class],     e.package_name,     e.xe_event_name FROM sys.trace_events t INNER JOIN dbo.trace_xe_event_map e     ON t.trace_event_id = e.trace_event_id There are a couple things you’ll notice as you peruse the output of this query: For the most part, the names of Events are fairly close to the original Event Class; eg. SP:CacheMiss == sp_cache_miss, and so on. We’ve mostly stuck to a one to one mapping between Event Classes and Events, but there are a few cases where we have combined when it made sense. For example, Data File Auto Grow, Log File Auto Grow, Data File Auto Shrink & Log File Auto Shrink are now all covered by a single event named database_file_size_change. This just seemed like a “smarter” implementation for this type of event, you can get all the same information from this single event (grow/shrink, Data/Log, Auto/Manual growth) without having multiple different events. You can use Predicates if you want to limit the output to just one of the original Event Class measures. There are some Event Classes that did not make the cut and were not migrated. These fall into two categories; there were a few Event Classes that had been deprecated, or that just did not make sense, so we didn’t migrate them. (You won’t find an Event related to mounting a tape – sorry.) The second class is bigger; with rare exception, we did not migrate any of the Event Classes that were related to Security Auditing using SQL Trace. We introduced the SQL Audit feature in SQL Server 2008 and that will be the compliance and auditing feature going forward. Doing this is a very deliberate decision to support separation of duties for DBAs. There are separate permissions required for SQL Audit and Extended Events tracing so you can assign these tasks to different people if you choose. (If you’re wondering, the permission for Extended Events is ALTER ANY EVENT SESSION, which is covered by CONTROL SERVER.) Action Mapping The table dbo.trace_xe_action_map exists in the master database with the following structure: Column_name Type trace_column_id smallint package_name nvarchar xe_action_name nvarchar You can find more details by joining this to sys.trace_columns on the trace_column_id field. SELECT     c.trace_column_id,     c.name [column_name],     a.package_name,     a.xe_action_name FROM sys.trace_columns c INNER JOIN    dbo.trace_xe_action_map a     ON c.trace_column_id = a.trace_column_id If you examine this list, you’ll notice that there are relatively few Actions that map to SQL Trace Columns given the number of Columns that exist. This is not because we forgot to migrate all the Columns, but because much of the data for individual Event Classes is included as part of the EventData fields of the equivalent Events so there is no need to specify them as Actions. Putting it all together If you’ve spent a bunch of time figuring out the inner workings of SQL Trace, and who hasn’t, then you probably know that the typically set of Columns you find associated with any given Event Class in SQL Profiler is not fix, but is determine by the contents of the table sys.trace_event_bindings. We’ve used this table along with the mapping tables to produce a list of Event + Action combinations that duplicate the SQL Profiler Event Class definitions using the following query, which you can also find in the Books Online topic How To: View the Extended Events Equivalents to SQL Trace Event Classes. USE MASTER; GO SELECT DISTINCT    tb.trace_event_id,    te.name AS 'Event Class',    em.package_name AS 'Package',    em.xe_event_name AS 'XEvent Name',    tb.trace_column_id,    tc.name AS 'SQL Trace Column',    am.xe_action_name as 'Extended Events action' FROM (sys.trace_events te LEFT OUTER JOIN dbo.trace_xe_event_map em    ON te.trace_event_id = em.trace_event_id) LEFT OUTER JOIN sys.trace_event_bindings tb    ON em.trace_event_id = tb.trace_event_id LEFT OUTER JOIN sys.trace_columns tc    ON tb.trace_column_id = tc.trace_column_id LEFT OUTER JOIN dbo.trace_xe_action_map am    ON tc.trace_column_id = am.trace_column_id ORDER BY te.name, tc.name As you might imagine, it’s also possible to map an existing trace definition to the equivalent event session by judicious use of fn_trace_geteventinfo joined with the two mapping tables. This query extracts the list of Events and Actions equivalent to the trace with ID = 1, which is most likely the Default Trace. You can find this query, along with a set of other queries and steps required to migrate your existing traces over to Extended Events in the Books Online topic How to: Convert an Existing SQL Trace Script to an Extended Events Session. USE MASTER; GO DECLARE @trace_id int SET @trace_id = 1 SELECT DISTINCT el.eventid, em.package_name, em.xe_event_name AS 'event'    , el.columnid, ec.xe_action_name AS 'action' FROM (sys.fn_trace_geteventinfo(@trace_id) AS el    LEFT OUTER JOIN dbo.trace_xe_event_map AS em       ON el.eventid = em.trace_event_id) LEFT OUTER JOIN dbo.trace_xe_action_map AS ec    ON el.columnid = ec.trace_column_id WHERE em.xe_event_name IS NOT NULL AND ec.xe_action_name IS NOT NULL You’ll notice in the output that the list doesn’t include any of the security audit Event Classes, as I wrote earlier, those were not migrated. But wait…there’s more! If this were an infomercial there’d by some obnoxious guy next to me blogging “Well Mike…that’s pretty neat, but I’m sure you can do more. Can’t you make it even easier to migrate from SQL Trace?”  Needless to say, I’d blog back, in an overly excited way, “You bet I can' obnoxious blogger side-kick!” What I’ve got for you here is a Extended Events Team Blog only special – this tool will not be sold in any store; it’s a special offer for those of you reading the blog. I’ve wrapped all the logic of pulling the configuration information out of an existing trace and and building the Extended Events DDL statement into a handy, dandy CLR stored procedure. Once you load the assembly and register the procedure you just supply the trace id (from sys.traces) and provide a name for the event session. Run the procedure and out pops the DDL required to create an equivalent session. Any aspects of the trace that could not be duplicated are included in comments within the DDL output. This procedure does not actually create the event session – you need to copy the DDL out of the message tab and put it into a new query window to do that. It also requires an existing trace (but it doesn’t have to be running) to evaluate; there is no functionality to parse t-sql scripts. I’m not going to spend a bunch of time explaining the code here – the code is pretty well commented and hopefully easy to follow. If not, you can always post comments or hit the feedback button to send us some mail. Sample code: TraceToExtendedEventDDL   Installing the procedure Just in case you’re not familiar with installing CLR procedures…once you’ve compile the assembly you can load it using a script like this: -- Context to master USE master GO -- Create the assembly from a shared location. CREATE ASSEMBLY TraceToXESessionConverter FROM 'C:\Temp\TraceToXEventSessionConverter.dll' WITH PERMISSION_SET = SAFE GO -- Create a stored procedure from the assembly. CREATE PROCEDURE CreateEventSessionFromTrace @trace_id int, @session_name nvarchar(max) AS EXTERNAL NAME TraceToXESessionConverter.StoredProcedures.ConvertTraceToExtendedEvent GO Enjoy! -Mike

  Read the article

• ASP.NET MVC: Converting business objects to select list items

  - by DigiMortal

  Some of our business classes are used to fill dropdown boxes or select lists. And often you have some base class for all your business classes. In this posting I will show you how to use base business class to write extension method that converts collection of business objects to ASP.NET MVC select list items without writing a lot of code. BusinessBase, BaseEntity and other base classes I prefer to have some base class for all my business classes so I can easily use them regardless of their type in contexts I need. NB! Some guys say that it is good idea to have base class for all your business classes and they also suggest you to have mappings done same way in database. Other guys say that it is good to have base class but you don’t have to have one master table in database that contains identities of all your business objects. It is up to you how and what you prefer to do but whatever you do – think and analyze first, please. :) To keep things maximally simple I will use very primitive base class in this example. This class has only Id property and that’s it. public class BaseEntity {     public virtual long Id { get; set; } } Now we have Id in base class and we have one more question to solve – how to better visualize our business objects? To users ID is not enough, they want something more informative. We can define some abstract property that all classes must implement. But there is also another option we can use – overriding ToString() method in our business classes. public class Product : BaseEntity {     public virtual string SKU { get; set; }     public virtual string Name { get; set; }       public override string ToString()     {         if (string.IsNullOrEmpty(Name))             return base.ToString();           return Name;     } } Although you can add more functionality and properties to your base class we are at point where we have what we needed: identity and human readable presentation of business objects. Writing list items converter Now we can write method that creates list items for us. public static class BaseEntityExtensions {            public static IEnumerable<SelectListItem> ToSelectListItems<T>         (this IList<T> baseEntities) where T : BaseEntity     {         return ToSelectListItems((IEnumerator<BaseEntity>)                    baseEntities.GetEnumerator());     }       public static IEnumerable<SelectListItem> ToSelectListItems         (this IEnumerator<BaseEntity> baseEntities)     {         var items = new HashSet<SelectListItem>();           while (baseEntities.MoveNext())         {             var item = new SelectListItem();             var entity = baseEntities.Current;               item.Value = entity.Id.ToString();             item.Text = entity.ToString();               items.Add(item);         }           return items;     } } You can see here to overloads of same method. One works with List<T> and the other with IEnumerator<BaseEntity>. Although mostly my repositories return IList<T> when querying data there are always situations where I can use more abstract types and interfaces. Using extension methods in code In your code you can use ToSelectListItems() extension methods like shown on following code fragment. ... var model = new MyFormModel(); model.Statuses = _myRepository.ListStatuses().ToSelectListItems(); ... You can call this method on all your business classes that extend your base entity. Wanna have some fun with this code? Write overload for extension method that accepts selected item ID.

  Read the article

• Multi-Threaded ObservableCollection and NotifyCollectionChanged Wrapper

  These classes should solve the multi-threaded issues plaguing the INotifyCollectionChanged classes for good.

  Read the article

• I have written an SQL query but I want to optimize it [closed]

  - by ankit gupta

  is there any way to do this using minimum no of joins and select? 2 tables are involved in this operation transaction_pci_details and transaction SELECT t6.transaction_pci_details_id, t6.terminal_id, t6.transaction_no, t6.transaction_id, t6.transaction_type, t6.reversal_flag, t6.transmission_date_time, t6.retrivel_ref_no, t6.card_no,t6.card_type, t6.expires_on, t6.transaction_amount, t6.currency_code, t6.response_code, t6.action_code, t6.message_reason_code, t6.merchant_id, t6.auth_code, t6.actual_trans_amnt, t6.bal_card_amnt, t5.sales_person_id FROM TRANSACTION AS t5 INNER JOIN ( SELECT t4.transaction_pci_details_id, t4.terminal_id, t4.transaction_no, t4.transaction_id, t4.transaction_type, t4.reversal_flag, t4.transmission_date_time, t4.retrivel_ref_no, t4.card_no, t4.card_type, t4.expires_on, t4.transaction_amount, t4.currency_code, t4.response_code, t4.action_code, t3.message_reason_code, t4.merchant_id, t4.auth_code, t4.actual_trans_amnt, t4.bal_card_amnt FROM ( SELECT* FROM transaction_pci_details WHERE message_reason_code LIKE '%OUT%'|| message_reason_code LIKE '%FAILED%' /*we can add date here*/ UNION ALL SELECT t2.transaction_pci_details_id, t2.terminal_id, t2.transaction_no, t2.transaction_id, t2.transaction_type, t2.reversal_flag, t2.transmission_date_time, t2.retrivel_ref_no, t2.card_no, t2.card_type, t2.expires_on, t2.transaction_amount, t2.currency_code, t2.response_code, t2.action_code, t2.message_reason_code, t2.merchant_id, t2.auth_code, t2.actual_trans_amnt, t2.bal_card_amnt FROM ( SELECT transaction_id FROM TRANSACTION WHERE transaction_type_id = 8 ) AS t1 INNER JOIN ( SELECT * FROM transaction_pci_details WHERE message_reason_code LIKE '%appro%' /*we can add date here*/ ) AS t2 ON t1.transaction_id = t2.transaction_id ) AS t3 INNER JOIN ( SELECT* FROM transaction_pci_details WHERE action_code LIKE '%REQ%' /*we can add date here*/ ) AS t4 ON t3.transaction_pci_details_id - t4.transaction_pci_details_id = 1 ) AS t6 ON t5.transaction_id = t6.transaction_id

  Read the article

• Why and when should I make a class 'static'? What is the purpose of 'static' keyword on classes?

  - by Saeed Neamati

  The static keyword on a member in many languages mean that you shouldn't create an instance of that class to be able to have access to that member. However, I don't see any justification to make an entire class static. Why and when should I make a class static? What benefits do I get from making a class static? I mean, after declaring a static class, one should still declare all members which he/she wants to have access to without instantiation, as static too. This means that for example, Math class could be declared normal (not static), without affecting how developers code. In other words, making a class static or normal is kind of transparent to developers.

  Read the article

• How To Build An Enterprise Application - Introduction

  - by Tuan Nguyen

  An enterprise application is a software which fulfills 4 core quality attributes: Reliability Flexibility Reusability Maintainability Reliability is the ability of a system or component to perform its required functions under stated conditions for a specific period of time. Because there are no ways more than testing to make sure a system is reliability, we can exchange the term reliability with the term testability. Flexibility is the ability of changing a system's core features without violating unrelated features or components. Although flexibility can helps us to achieve interoperability easily but the opposite is not true. For example, a program might run on multiple platforms, contains logic for many scenarios but that wouldn't mean it was flexibility if it forces us rewrite code in all components when we just want to change some aspects of a feature it had. Reusability is the ability of sharing one or more system's components for another system. We should just open a component's reusability in the context in which it is used. For example, we write classes that implement UI logic and deliver them to only classes which implementing UI. Maintainability is the ability of adding or removing features to a system after it was released. Maintainability consists of many factors such as readability, analyzability, extensibility therein extensibility is critical. Maintainability requires us to write code that is longer and complexer than normal but it doesn't mean we introduce unneccessarily complex code. We always try to make our code clear and transparent to everyone. An application enterprise is built on an enterprise design which consists of two parts: low-level design and high-level design. At low-level design, it focuses on building loose-coupled classes or components. Particularly, it recommends: Each class or component undertakes only single responsibility (design based on unit test) Classes or components implement and work through interfaces (design based on contract) Dependency relationship between classes and components could be injected at run-time (design based on dependency) At high-level design, it focuses on architecting system into tiers and layers. Particularly, it recommends: Divide system into subsystems for deployment. Each subsytem is called a tier. Typical, an enterprise application would have 3 tiers as illustrated in the following figure: Arrange classes and components to logical containers called layers. Typical, an enterprise application would have 5 layers as illustrated in the following figure

  Read the article

• Silverlight binary serialization using Protobuf-net

  how to serialize a pure .NET object classes to a fast binary data

  Read the article

• Best approach for utility class library using Visual Studio

  - by gregsdennis

  I have a collection of classes that I commonly (but not always) use when developing WPF applications. The trouble I have is that if I want to use only a subset of the classes, I have three options: Distribute the entire DLL. While this approach makes code maintenance easier, it does require distributing a large DLL for minimal code functionality. Copy the classes I need to the current application. This approach solves the problem of not distributing unused code, but completely eliminates code maintenance. Maintain each class/feature in a separate project. This solves both problems from above, but then I have dramatically increased the number of files that need to be distributed, and it bloats my VS solution with tiny projects. Ideally, I'd like a combination of 1 & 3: A single project that contains all of my utility classes but builds to a DLL containing only the classes that are used in the current application. Are there any other common approaches that I haven't considered? Is there any way to do what I want? Thank you.

  Read the article

• Effective template system

  - by Alex

  I'm building a content management system, and need advice on which theming structure should I adopt. A few options (This is not a complete list): Wordpress style: the controller decides what template to load based on the user request, like: home page / article archive / single article page etc. each of these templates are unrelated to other templates, and must exist within the theme the theme developer decides if (s)he want to use inner-templates (like "sidebar", "sidebar item"), and includes them manually where (s)he thinks are needed. Drupal style: the controller gives control to the theme developer only to inner-templates; if they don't exist it falls back internally to some default templates (I find this very restrictive) Funky style: the controller only loads a "index.php" template and provides the theme developer conditional tags, which he can use to include inner-templates if (s)he wants. Among these styles, or others what style of template system allows for fast development and a more concise design and implementation.

  Read the article

• Why is there no service-oriented language?

  - by Wolfgang

  Edit: To avoid further confusion: I am not talking about web services and such. I am talking about structuring applications internally, it's not about how computers communicate. It's about programming languages, compilers and how the imperative programming paradigm is extended. Original: In the imperative programming field, we saw two paradigms in the past 20 years (or more): object-oriented (OO), and service-oriented (SO) aka. component-based (CB). Both paradigms extend the imperative programming paradigm by introducing their own notion of modules. OO calls them objects (and classes) and lets them encapsulates both data (fields) and procedures (methods) together. SO, in contrast, separates data (records, beans, ...) from code (components, services). However, only OO has programming languages which natively support its paradigm: Smalltalk, C++, Java and all other JVM-compatibles, C# and all other .NET-compatibles, Python etc. SO has no such native language. It only comes into existence on top of procedural languages or OO languages: COM/DCOM (binary, C, C++), CORBA, EJB, Spring, Guice (all Java), ... These SO frameworks clearly suffer from the missing native language support of their concepts. They start using OO classes to represent services and records. This leads to designs where there is a clear distinction between classes that have methods only (services) and those that have fields only (records). Inheritance between services or records is then simulated by inheritance of classes. Technically, its not kept so strictly but in general programmers are adviced to make classes to play only one of the two roles. They use additional, external languages to represent the missing parts: IDL's, XML configurations, Annotations in Java code, or even embedded DSL like in Guice. This is especially needed, but not limited to, since the composition of services is not part of the service code itself. In OO, objects create other objects so there is no need for such facilities but for SO there is because services don't instantiate or configure other services. They establish an inner-platform effect on top of OO (early EJB, CORBA) where the programmer has to write all the code that is needed to "drive" SO. Classes represent only a part of the nature of a service and lots of classes have to be written to form a service together. All that boiler plate is necessary because there is no SO compiler which would do it for the programmer. This is just like some people did it in C for OO when there was no C++. You just pass the record which holds the data of the object as a first parameter to the procedure which is the method. In a OO language this parameter is implicit and the compiler produces all the code that we need for virtual functions etc. For SO, this is clearly missing. Especially the newer frameworks extensively use AOP or introspection to add the missing parts to a OO language. This doesn't bring the necessary language expressiveness but avoids the boiler platform code described in the previous point. Some frameworks use code generation to produce the boiler plate code. Configuration files in XML or annotations in OO code is the source of information for this. Not all of the phenomena that I mentioned above can be attributed to SO but I hope it clearly shows that there is a need for a SO language. Since this paradigm is so popular: why isn't there one? Or maybe there are some academic ones but at least the industry doesn't use one.

  Read the article

• College for Game Development [closed]

  - by Cole Adams

  I am currently a Freshman Computer Science Major at Samford University, but I am realizing that the actual field I want to get into is Game Development. I go to all of these classes that are supposed to make you well rounded that have nothing to do with what I want to do and frankly, after 18 years of schooling, I am sick of having to be in classes like that. I want to go to a Game Design/Development school where that is the priority and I am not overburdened with useless classes. At this point I am so tired of the Samford classes already that I am heavily considering taking next semester off and just getting a job and focusing on learning programming on my own or something like that. My question is what would be some good schools to apply to for enrollment in 2013 and what does it take to get into these schools? Thanks in advanced.

  Read the article

• A strong component keeps everything together

  - by Justin Paul-Oracle

  Most of the times you implement a WebCenter Content based system, you require some sort of customization. Sometimes these customizations need a Java class or two, or libraries (for example, the JavaMail API), or Database Objects (like new tables, views, indexes, etc). I have seen that libraries and Database Objects are usually put in place using manual steps. This means that the library jar files are copied to one of the common classes directory (set in the Content CLASSPATH variable) and/or the database scripts are executed manually. I have also seen people place the custom Java classes in the common classes directory. While this may seem like an easy solution, think about a scenario where you need to disable or uninstall the component or if you have to upgrade or migrate the system. You have to keep these manual steps documented and execute them every time you encounter the above scenarios. It is very common that some of these manual steps are missed when you have multiple teams and people working on the system. Here are a few points to ponder upon: Place all your custom Java classes within your component. Create a new directory, say ${COMPONENT_DIR}/classes, and place your code there. You can choose to bundle all your classes into a jar or you can place the entire class directory structure. Add a path entry to the Build Settings so that it is bundled with the component when you build it. You also need to update the Custom Class Path and the Custom Class Path Load Order under the Advanced Build Settings. This will ensure that the system CLASSPATH is updated to add this new directory. Create a new component for any new library that you want to add. Add the appropriate path entries to the Build Settings so that it is bundled with the component when you build it. You also need to update the Custom Class Path, Custom Class Path Load Order and/or the Custom Library Path under the Advanced Build Settings. Enter a comma separated list of features that this component will provide. When you create other components that will use the features exposed by this component, make sure that you specify a dependency to this library component by specifying the comma separated list of features in the Advanced Build Settings. The component wizard allows you to create custom install/uninstall Java code. The wizard will create a install filter class when you check the “Has Install” checkbox on the “Install/Uninstall Settings” tab. Consider using this filter class to create database objects when you install the component and drop the objects when you uninstall the component. If you do a lot of custom component development, consider creating a install/uninstall Java class, which can execute queries defined within the component. To sum up, whenever you write a new custom component, make sure that you bundle everything within the component.

  Read the article

• How to properly structure a project in winform?

  - by user850010

  A while ago I started to create a winform application and at that time it was small and I did not give any thought of how to structure the project. Since then I added additional features as I needed and the project folder is getting bigger and bigger and now I think it is time to structure the project in some way, but I am not sure what is the proper way, so I have few questions. How to properly restructure the project folder? At the moment I am thinking of something like this: Create Folder for Forms Create Folder for Utility classes Create Folder for Classes that contain only data What is the naming convention when adding classes? Should I also rename classes so that their functionality can be identified by just looking at their name? For example renaming all forms classes, so that their name ends with Form. Or is this not necessary if special folders for them are created? What to do, so that not all the code for main form ends up in Form1.cs Another problem I encountered is that as the main form is getting more massive with each feature I add, the code file (Form1.cs) is getting really big. I have for example a TabControl and each tab has bunch of controls and all the code ended up in Form1.cs. How to avoid this? Also, Do you know any articles or books that deal with these problems?

  Read the article

• Struggling with the Single Responsibility Principle

  - by AngryBird

  Consider this example: I have a website. It allows users to make posts (can be anything) and add tags that describe the post. In the code, I have two classes that represent the post and tags. Lets call these classes Post and Tag. Post takes care of creating posts, deleting posts, updating posts, etc. Tag takes care of creating tags, deleting tags, updating tags, etc. There is one operation that is missing. The linking of tags to posts. I am struggling with who should do this operation. It could fit equally well in either class. On one hand, the Post class could have a function that takes a Tag as a parameter, and then stores it in a list of tags. On the other hand, the Tag class could have a function that takes a Post as a parameter and links the Tag to the Post. The above is just an example of my problem. I am actually running into this with multiple classes that are all similar. It could fit equally well in both. Short of actually putting the functionality in both classes, what conventions or design styles exist to help me solve this problem. I am assuming there has to be something short of just picking one? Maybe putting it in both classes is the correct answer?

  Read the article

• Defining .NET Components with Namespaces

  A .NET software component is a compiled set of classes that provide a programmable interface that is used by consumer applications for a service. As a component is no more than a logical grouping of classes, what then is the best way to define the boundaries of a component within the .NET framework? How should the classes inter-operate? Patrick Smacchia, the lead developer of NDepend, discusses the issues and comes up with a solution.

  Read the article

• .NET Wrapper for Setup API (Parses INF, OEM Files)

  .NET classes for parsing driver.INF and txtsetup.OEM using the Setup API

  Read the article

• Easily Get and Compare OS Version Information

  A couple of classes to make checking the host OS version easy and error-free

  Read the article

• Complete Math Library for use in OpenGL ES 2.0 Game?

  - by Bunkai.Satori

  Are you aware of a complete (or almost complete) cross platform math library for use in OpenGL ES 2.0 games? The library should contain: Matrix2x2, Matrix 3x3, Matrix4x4 classes Quaternions Vector2, Vector3, Vector4 Classes Euler Angle Class Operations amongh the above mentioned classes, conversions, etc.. Standardly used math operations in 3D graphics (Dot Product, Cross Product, SLERP, etc...) Is there such Math API available either standalone or as a part of any package? Programming Language: Visual C++ but planned to be ported to OS X and Android OS.

  Read the article

• Creating a shared library that might be used with desktop applications and web projects

  - by dreza

  I have been involved in a number of MVC.NET and c# desktop projects in our company over the last year or so while also managing to kept my nose poked into other projects (in a read-only learning capacity of course). From this I've noticed that across the various projects and teams there is a-lot of functionality that has been well designed against good interfaces and abstractions. Because we tend to like our own work at times, I noticed a couple of projects had the exact same class, method copied into it as it had obviously worked on one and so was easily moved to a new project (probably by the same developer who originally wrote it) I mentioned this fact in one of our programmer meetings we have occasionally and suggested we pull some of this functionality into a core company library that we can build up over time and use across multiple projects. Everyone agreed and I started looking into this possibility. However, I've come across a stumbling block pretty early on. Our team primarily focuses on MVC at the moment and we have projects mainly in 2.0 but are starting to branch to 3.0. We also have a number of desktop applications that might benefit from some shared classes and basic helper methods. Initially when creating this DLL I included some shared classes that could be used across any project type (Web, Client etc) but then I started looking at adding some shared modules that would be useful in our MVC applications only. However this meant I had to include a reference to some Microsoft Web DLL's in order to leverage some of the classes I was creating (at this stage MVC 2.0). Now my issue is that we have a shared DLL that has references to web specific libraries that could also possibly be used in a client application. Not only that, our DLL referenced initially MVC 2.0 and we will eventually move onto MVC 3.0 for all projects. But alot of the classes in this library I expect to still be relevant to MVC 3 etc Our code within this DLL is separated into it's own namespaces such as: CompanyDLL.Primitives CompanyDLL.Web.Mvc CompanyDLL.Helpers etc etc So, my questions are: Is it OK to do a shared library like this, or if we have web specific features in it should we create a separate web DLL only targeted at a specific framework or MVC version? If it's OK, what kind of issues might we face when using the library that references MVC 2 in a MVC 3 project for example. I would be thinking that we might run into some sort of compatibility issue, or even issues where the developers using the library doesn't realize they need MVC 2.0 libraries. They might only want to use some of the generic classes etc The concept seemed like a good idea at the time, but I'm starting to think maybe it's not really a practical solution. But the number of times I've seen copied classes and methods across projects because they are proven tested code is a bit unnerving to be perfectly honest!

  Read the article

• Can I use a wildcard to denote subdirectories as opposed to just files in the Windows Command Prompt

  - by Dinosaurus

  I know I can use a wildcard to list the files in a single directory: dir *.java However, does anyone know if it is possible to denote a subdirectory with a wildcard as well? I would like to do something like dir classes/*/*.java Where, it will list all the java files in every subdirectory beneath the classes directory. So, if there is: classes/cs1100/ classes/cs1200/ classes/cs1500/ It will list all the java files within these. Note, I'm not using this specifically for the "Dir" command, but instead another command line tool that accepts a list of files. But, if it works for Dir, it shoudl work in my other program as well.

  Read the article

• Object Factory Design Pattern: Register Creator Functions Using TypeLists and Template Metaprogrammi

  How to register classes for Object Factory using TypeList and Template Metaprogramming

  Read the article

• What is a 'good number' of exceptions to implement for my library?

  - by Fuzz

  I've always wondered how many different exception classes I should implement and throw for various pieces of my software. My particular development is usually C++/C#/Java related, but I believe this is a question for all languages. I want to understand what is a good number of different exceptions to throw, and what the developer community expect of a good library. The trade-offs I see include: More exception classes can allow very fine grain levels of error handling for API users (prone to user configuration or data errors, or files not being found) More exception classes allows error specific information to be embedded in the exception, rather than just a string message or error code More exception classes can mean more code maintenance More exception classes can mean the API is less approachable to users The scenarios I wish to understand exception usage in include: During 'configuration' stage, which might include loading files or setting parameters During an 'operation' type phase where the library might be running tasks and doing some work, perhaps in another thread Other patterns of error reporting without using exceptions, or less exceptions (as a comparison) might include: Less exceptions, but embedding an error code that can be used as a lookup Returning error codes and flags directly from functions (sometimes not possible from threads) Implemented an event or callback system upon error (avoids stack unwinding) As developers, what do you prefer to see? If there are MANY exceptions, do you bother error handling them separately anyway? Do you have a preference for error handling types depending on the stage of operation?

  Read the article

• Easily retrieve email information from .EML files -- Revised

  C# classes that upload an EML into a System.Net.Mail.MailMessage

  Read the article

• Java best practice Interface - subclasses and constants

  - by Taiko

  In the case where a couple of classes implements an interface, and those classes have a couple of constants in common (but no functions), were should I put this constant ? I've had this problem a couple of times. I have this interface : DataFromSensors that I use to hide the implementations of several sub classes like DataFromHeartRateMonitor DataFromGps etc... For some reason, those classes uses the same constants. And there's nowere else in the code were it is used. My question is, were should I put those constants ? Not in the interface, because it has nothing to do with my API Not in a static Constants class, because I'm trying to avoid those Not in a common abstract class, that would stand between the interface and the subclasses, because I have no functions in common, only a couple of constants (TIMEOUT_DURATION, UUID, those kind of things) I've read best practice for constants and interface to define constants but they don't really answer my question. Thanks !

  Read the article

• STL WebServer

  A set of classes written in STL that implement a web server

  Read the article

< Previous Page | 72 73 74 75 76 77 78 79 80 81 82 83  | Next Page >