Search Results

Search found 17731 results on 710 pages for 'programming practices'.

Page 191/710 | < Previous Page | 187 188 189 190 191 192 193 194 195 196 197 198  | Next Page >

  • How to use a 3rd party control inside the viewmodel?

    - by Sander
    I have a 3rd party control which among other things performs loading of some data. I want my viewmodel to keep track of this load operation and adjust its own state accordingly. If it were up to me, I'd do the data loading far away from the view, but it is not. So, I seem to be in the situation where my viewmodel depends on my view. How do I best handle this? I feel rather dirty making the view publish events to the viewmodel but I don't see any other reasonable way to get this info into the viewmodel. A similar situation might crop up with standard controls, too - imagine if your viewmodel depends on the events coming from a MediaElement - how do you properly model this? Do you put the MediaElement into the viewmodel? That doesn't sound right. If publishing the events to the viewmodel is indeed the most reasonable way, is there some common pattern used for this? How do you do it?

    Read the article

  • What is so bad about Singletons

    - by Ewan Makepeace
    The Singleton pattern is a fully paid up member of the GoF Patterns Book but lately seems rather orphaned by the developer world. I still use quite a lot of singletons, especially for Factory classes, and while you have to be a bit careful about multithreading issues (like any class actually) fail to see why they are so awful. This site especially seems to assume that everyone agrees that Singletons are evil. Why?

    Read the article

  • With MVVM, does each UI window have its own ViewModel?

    - by j0rd4n
    When I'm designing multiple views under the MVVM pattern, does each view get its own ViewModel or do they all share the same one? I understand that this is ultimately a flexible decision, but what is the best practice? My gut tells me to have a ViewModel for each view (i.e. each separate UI window). All of the blog examples of MVVM show a single view but not much beyond that.

    Read the article

  • Eclipse: Should I create a workspace for each project ?

    - by Zombies
    I am simply wondering whether it is best to put all of my Eclipse projects into one workspace, or do a 1 workspace per 1 project. I am just a solo developer, for hobby more or less, but the apps I create do actually have production versions that are running on rather frequent cron jobs, so its almost like an amateur production environment. The only problems I have noticed so far is for exporting JARs, I have the potential to include source files from other projects which seems like it could get messy (maybe?).

    Read the article

  • What's the best way to write a maintainable web scraping app?

    - by Benj
    I wrote a perl script a while ago which logged into my online banking and emailed me my balance and a mini-statement every day. I found it very useful for keeping track of my finances. The only problem is that I wrote it just using perl and curl and it was quite complicated and hard to maintain. After a few instances of my bank changing their webpage I got fed up of debugging it to keep it up to date. So what's the best way of writing such a program in such a way that it's easy to maintain? I'd like to write a nice well engineered version in either Perl or Java which will be easy to update when the bank inevitably fiddle with their web site.

    Read the article

  • UX Design Question: Should a multi step wizard save the form contents when the user clicks 'go back'

    - by Ashwin Prabhu
    I am developing a web application that collects data over multiple steps through a wizard. Steps are generally not interdependent, in that data input at each step has little or no effect on the consequent steps. However each step may have a set of validations which determine whether the user can progress to the next step by clicking 'continue' What should be the behavior when the user clicks previous? a Quickly move to the previous page, thus losing all the unsaved data in the form. Prompting the user with a warning is an option, but it can become irritating quite soon. b Move to the previous page saving all the data in the current step - without triggering validations, so that when the user comes back she sees the form in the same state that she left it in. c any other behaviour All opinions are welcome :)

    Read the article

  • What is a 'better' approach to query/save from server: DTO or Wcf Data Services?

    - by bonefisher
    From my perspective, the Data Services and their query approach is useful when querying simple object graphs from your server-side domain model. But when you want to query complex dependencies I couldn't create anything good out of it. The classic DTO approach is fine-grained and can handle everything, but the downside is that you have to create Dto classes for every type of server-request which is time consuming and you have to synchronize the Dto type with your domain entity/business logic.

    Read the article

  • Is Assert.Fail() considered bad practice?

    - by Mendelt
    I use Assert.Fail a lot when doing TDD. I'm usually working on one test at a time but when I get ideas for things I want to implement later I quickly write an empty test where the name of the test method indicates what I want to implement as sort of a todo-list. To make sure I don't forget I put an Assert.Fail() in the body. When trying out xUnit.Net I found they hadn't implemented Assert.Fail. Of course you can always Assert.IsTrue(false) but this doesn't communicate my intention as well. I got the impression Assert.Fail wasn't implemented on purpose. Is this considered bad practice? If so why? @Martin Meredith That's not exactly what I do. I do write a test first and then implement code to make it work. Usually I think of several tests at once. Or I think about a test to write when I'm working on something else. That's when I write an empty failing test to remember. By the time I get to writing the test I neatly work test-first. @Jimmeh That looks like a good idea. Ignored tests don't fail but they still show up in a separate list. Have to try that out. @Matt Howells Great Idea. NotImplementedException communicates intention better than assert.Fail() in this case @Mitch Wheat That's what I was looking for. It seems it was left out to prevent it being abused in another way I abuse it.

    Read the article

  • When should we use Views, Temporary Tables and Direct Queries ? What are the Performance issues in a

    - by Shantanu Gupta
    I want to know the performance of using Views, Temp Tables and Direct Queries Usage in a Stored Procedure. I have a table that gets created every time when a trigger gets fired. I know this trigger will be fired very rare and only once at the time of setup. Now I have to use that created table from triggers at many places for fetching data and I confirms it that no one make any changes in that table. i.e ReadOnly Table. I have to use this tables data along with multiple tables to join and fetch result for further queries say select * from triggertable By Using temp table select ... into #tx from triggertable join t2 join t3 and so on select a,b, c from #tx --do something select d,e,f from #tx ---do somethign --and so on --around 6-7 queries in a row in a stored procedure. By Using Views create view viewname ( select ... from triggertable join t2 join t3 and so on ) select a,b, c from viewname --do something select d,e,f from viewname ---do somethign --and so on --around 6-7 queries in a row in a stored procedure. This View can be used in other places as well. So I will be creating at database rather than at sp By Using Direct Query select a,b, c from select ... into #tx from triggertable join t2 join t3 join ... --do something select a,b, c from select ... into #tx from triggertable join t2 join t3 join ... --do something . . --and so on --around 6-7 queries in a row in a stored procedure. Now I can create a view/temporary table/ directly query usage in all upcoming queries. What would be the best to use in this case.

    Read the article

  • Giving the script tag an ID

    - by The Code Pimp
    Hi guys, i came across a scenario where giving a <script> element an "ID" would solve a problem easily. However, after reading about the script tag at w3schools and quirksmode, it seems doing so could have some unforeseen consequences. Has anyone come across any of these issues with modern browsers such as Chrome, Safari, FF3 up and IE 7 up? Thanks

    Read the article

  • [MySQL] Efficiently store last X records per item

    - by Saif Bechan
    I want to store the last X records in an MySQL database in an efficient way. So when the 4th record is stored the first should be deleted. The way I do this not is first run a query getting the items. Than check what I should do then insert/delete. There has to be a better way to do this. Any suggestions? Edit I think I should add that the records stored do not have a unique number. They have a mixed par. For example article_id and user_id. Then I want to make a table with the last X items for user_x. Just selecting the article from the table grouped by user and sorted by time is not an option for me. The table where I do the sort and group on has millions of records and gets hit a lot for no reason. So making a table in between with the last X records is way more effient. PS. I am not using this for articles and users.

    Read the article

  • Program structure in long running data processing python script

    - by fmark
    For my current job I am writing some long-running (think hours to days) scripts that do CPU intensive data-processing. The program flow is very simple - it proceeds into the main loop, completes the main loop, saves output and terminates: The basic structure of my programs tends to be like so: <import statements> <constant declarations> <misc function declarations> def main(): for blah in blahs(): <lots of local variables> <lots of tightly coupled computation> for something in somethings(): <lots more local variables> <lots more computation> <etc., etc.> <save results> if __name__ == "__main__": main() This gets unmanageable quickly, so I want to refactor it into something more manageable. I want to make this more maintainable, without sacrificing execution speed. Each chuck of code relies on a large number of variables however, so refactoring parts of the computation out to functions would make parameters list grow out of hand very quickly. Should I put this sort of code into a python class, and change the local variables into class variables? It doesn't make a great deal of sense tp me conceptually to turn the program into a class, as the class would never be reused, and only one instance would ever be created per instance. What is the best practice structure for this kind of program? I am using python but the question is relatively language-agnostic, assuming a modern object-oriented language features.

    Read the article

  • Standard Workflow when working with JPA

    - by jschoen
    I am currently trying to wrap my head around working with JPA. I can't help but feel like I am missing something or doing it the wrong way. It just seems forced so far. What I think I know so far is that their are couple of ways to work with JPA and tools to support this. You can do everything in Java using annotations, and let JPA (whatever implementation you decide to use) create your schema and update it when changes are made. You can use a tool to reverse engineer you database and generate the entity classes for you. When the schema is updated you have to regenerate these classes, or manually update them. There seems to be drawbacks to both, and benefits to both (as with all things). My question is in an ideal situation what is the standard workflow with JPA? Most schemas will require updates during the maintenance phase and especially during the development phase, so how is this handled?

    Read the article

  • How to not over-use jQuery?

    - by Fedyashev Nikita
    Typical jQuery over-use: $('button').click(function() { alert('Button clicked: ' + $(this).attr('id')); }); Which can be simplified to: $('button').click(function() { alert('Button clicked: ' + this.id); }); Which is way faster. Can you give me any more examples of similar jQuery over-use?

    Read the article

  • Question about the benefit of using an ORM

    - by johnny
    I want to use an ORM for learning purposes and am try nhibernate. I am using the tutorial and then I have a real project. I can go the "old way" or use an ORM. I'm not sure I totally understand the benefit. On the one hand I can create my abstractions in code such that I can change my databases and be database independent. On the other it seems that if I actually change the database columns I have to change all my code. Why wouldn't I have my application without the ORM, change my database and change my code, instead of changing my database, orm, and code? Is it that they database structure doesn't change that much? I believe there are real benefits because ORMs are used by so many. I'm just not sure I get it yet. Thank you. EDIT: In the tutorial they have many files that are used to make the ORM work http://www.hibernate.org/362.html In the event of an application change, it seems like a lot of extra work just to say that I have "proper" abstraction layers. Because I'm new at it it doesn't look that easy to maintain and again seems like extra work, not less.

    Read the article

  • K/APL style programming in C++?

    - by anon
    I'm writing code in C++, but I really like K/APL's array-oriented style. Does anyone know of a good set of operator overloading tricks / macros / ... to allow some K/APL -style programming in C++? Thanks!

    Read the article

  • Is there anything bad in declaring static inner class inside interface in java?

    - by Roman
    I have an interface ProductService with method findByCriteria. This method had a long list of nullable parameters, like productName, maxCost, minCost, producer and so on. I refactored this method by introducing Parameter Object. I created class SearchCriteria and now method signature looks like this: findByCriteria (SearchCriteria criteria) I thought that instances of SearchCriteria are only created by method callers and are only used inside findByCriteria method, i.e.: void processRequest() { SearchCriteria criteria = new SearchCriteria () .withMaxCost (maxCost) ....... .withProducer (producer); List<Product> products = productService.findByCriteria (criteria); .... } and List<Product> findByCriteria(SearchCriteria criteria) { return doSmthAndReturnResult(criteria.getMaxCost(), criteria.getProducer()); } So I did not want to create separate public class for SearchCriteria and put it inside ProductServiceInterface: public interface ProductService { List<Product> findByCriteria (SearchCriteria criteria); static class SearchCriteria { ... } } Is there anything bad in this interface? Where whould you place SearchCriteria class?

    Read the article

  • Diminishing programmer wants to get back to programming

    - by Marcus TV
    I last programmed actively in 2002. It is almost 8 years now. I learned C and then moved to Visual Basic for our thesis project in the university. I would like to ask suggestions on what programming language should I learn and put to profitability use in areas such as desktop applications, web development, and database applications.

    Read the article

  • Why is using a common-lookup table to restrict the status of entity wrong?

    - by FreshCode
    According to Five Simple Database Design Errors You Should Avoid by Anith Sen, using a common-lookup table to store the possible statuses for an entity is a common mistake. Why is this wrong? I disagree that it's wrong, citing the example of jobs at a repair service with many possible statuses that generally have a natural flow, eg.: Booked In Assigned to Technician Diagnosing problem Waiting for Client Confirmation Repaired & Ready for Pickup Repaired & Couriered Irreparable & Ready for Pickup Quote Rejected Arguably, some of these statuses can be normalised to tables like Couriered Items, Completed Jobs and Quotes (with Pending/Accepted/Rejected statuses), but that feels like unnecessary schema complication. Another common example would be order statuses that restrict the status of an order, eg: Pending Completed Shipped Cancelled Refunded The status titles and descriptions are in one place for editing and are easy to scaffold as a drop-down with a foreign key for dynamic data applications. This has worked well for me in the past. If the business rules dictate the creation of a new order status, I can just add it to OrderStatus table, without rebuilding my code.

    Read the article

  • Configuration and Model-View

    - by HH
    I am using the Model-View pattern on a small application I'm writing. Here's the scenario: The model maintains a list of directories from where it can extract the data that it needs. The View has a Configuration or a Setting dialog where the user can modify this list of directories (the dialog has a JList displaying the list in addition to add and remove buttons). I need some advice from the community: The View needs to communicate these changes to the model. I thought first of adding to the model these methods: addDirectory() and removeDirectory(). But I am trying to limit the number of methods (or channels) that the View can use to communicate with and manipulate the model. Is there any good practice for this? Thank you.

    Read the article

  • must have tools for better quality code

    - by leon
    I just started my real development career and I want to know what set of tools/strategy that the community is using to write better quality code. To start, I use astyle to format my code doxygen to document my code gcc -Wall -Wextra -pedantic and clang -Wall -Wextra -pedantic to check all warnings What tools/strategy do you use to write better code? This question is open to all language and all platform.

    Read the article

  • Where do you extend classes in your rails application?

    - by ro
    Just about to extend the Array class with the following extension: class Array def shuffle! size.downto(1) { |n| push delete_at(rand(n)) } self end end However, I was wondering where a good place to keep these sort of extensions. I was thinking environment.rb or putting in its own file in the initializers directory.

    Read the article

< Previous Page | 187 188 189 190 191 192 193 194 195 196 197 198  | Next Page >