Search Results

Search found 674 results on 27 pages for 'refactor'.

Page 24/27 | < Previous Page | 20 21 22 23 24 25 26 27  | Next Page >

  • Formating a date field in the Model (Codeigniter)

    - by Landitus
    Hi, I', trying to re-format a date from a table in Codeigniter. The Controller is for a blog. I was succesfull when the date conversion happens in the View. I was hoping to convert the date in the Model to have things in order. This is the Model: class Novedades_model extends Model { function getAll() { $this->db->order_by('date','desc'); $query = $this->db->get('novedades'); if($query->num_rows() > 0) { foreach ($query->result() as $row) { $data[] = $row; } } return $data; } } This is part of the controller $this->load->model('novedades_model'); $data['records'] = $this->novedades_model->getAll(); Here's the date conversion as it happens in the View. This is inside the posts loop: <?php foreach($records as $row) : ?> <?php $fdate = "%d <abbr>%M</abbr> %Y"; $dateConv = mdate($fdate, mysql_to_unix($row->date)); ?> <div class="article section"> <span class="date"><?php echo $dateConv ;?></span> ... Keeps going ... How can I convert the date in the Model? Can I access the date key and refactor it?

    Read the article

  • Refactoring and assessment

    - by neitony
    I'm using javascript to toggle the display state of some objects based on the time of day. A sample of the code is given below. I was wondering if anyone could give a suggestion as to how I can refactor this code while at the same time improving the logic. switch(tcode) { case 'eur' : eur.setAttribute('style', 'display:block; opacity:0.5'); us.style.display = 'none'; asia.style.display = 'none'; us_inactive.style.display = 'block'; asia_inactive.style.display = 'block'; break; case 'us' : us.style.display = 'block'; eur.style.display = 'none'; asia.style.display = 'none'; eur_inactive.style.display = 'block'; asia_inactive.style.display = 'block'; break; case 'asia' : asia.setAttribute('style', 'display:block; opacity:0.5'); us.style.display = 'none'; eur.style.display = 'none'; eur_inactive.style.display = 'block'; us_inactive.style.display = 'block';

    Read the article

  • How to combine the multiple part linq into one query?

    - by user2943399
    Operator should be ‘AND’ and not a ‘OR’. I am trying to refactor the following code and i understood the following way of writing linq query may not be the correct way. Can somone advice me how to combine the following into one query. AllCompany.Where(itm => itm != null).Distinct().ToList(); if (AllCompany.Count > 0) { //COMPANY NAME if (isfldCompanyName) { AllCompany = AllCompany.Where(company => company["Company Name"].StartsWith(fldCompanyName)).ToList(); } //SECTOR if (isfldSector) { AllCompany = AllCompany.Where(company => fldSector.Intersect(company["Sectors"].Split('|')).Any()).ToList(); } //LOCATION if (isfldLocation) { AllCompany = AllCompany.Where(company => fldLocation.Intersect(company["Location"].Split('|')).Any()).ToList(); } //CREATED DATE if (isfldcreatedDate) { AllCompany = AllCompany.Where(company => company.Statistics.Created >= createdDate).ToList(); } //LAST UPDATED DATE if (isfldUpdatedDate) { AllCompany = AllCompany.Where(company => company.Statistics.Updated >= updatedDate).ToList(); } //Allow Placements if (isfldEmployerLevel) { fldEmployerLevel = (fldEmployerLevel == "Yes") ? "1" : ""; AllCompany = AllCompany.Where(company => company["Allow Placements"].ToString() == fldEmployerLevel).ToList(); }

    Read the article

  • jQuery .ready() automatically assigning variables for each element with ID in DOM

    - by Greg
    I have noticed some unexpected behaviour when using the jQuery .ready() function, whereby afterwards you can reference an element in the DOM simply by using its ID without prior declaration or assignment: <html> <script src="jquery.js"></script> <script> $(document).ready(function() { myowndiv.innerHTML = 'wow!' }); </script> <body> <div id="myowndiv"></div> </body> </html> I would have expected to have to declare and assign myowndiv with document.getElementById("myowndiv"); or $("#myowndiv"); before I could call innerHTML or anything else on it? Is this behaviour by design? Can anyone explain why? My fear is that if I refactor and end up not using .ready() or even using jQuery at all then my code will fail to execute. Cheers!

    Read the article

  • Design pattern for loading multiple message types

    - by lukem00
    As I was looking through SO I came across a question about handling multiple message types. My concern is - how do I load such a message in a neat way? I decided to have a separate class with a method which loads one message each time it's invoked. This method should create a new instance of a concrete message type (say AlphaMessage, BetaMessage, GammaMessage, etc.) and return it as a Message. class MessageLoader { public Message Load() { // ... } } The code inside the method is something which looks really awful to me and I would very much like to refactor it/get rid of it: Message msg = Message.Load(...); // load yourself from whatever source if (msg.Type == MessageType.Alpha) return new AlphaMessage(msg); if (msg.Type == MessageType.Beta) return new BetaMessage(msg); // ... In fact, if the whole design looks just too messy and you guys have a better solution, I'm ready to restructure the whole thing. If my description is too chaotic, please let me know what it's missing and I shall edit the question. Thank you all.

    Read the article

  • What are good examples of perfectly acceptable approaches to development that are NOT test driven development (TDD)?

    - by markbruns
    The TDD cycle is test, code, refactor, (repeat) and then ship. TDD implies development that is driven by testing, specifically that means understanding requirements and then writing tests first before developing or writing code. My natural inclination is a philosophical bias in favor of TDD; I would like to be convinced that there are other approaches that now work well or even better than TDD so I have asked this question. What are examples of perfectly acceptable approaches that NOT test driven development? I can think of plenty approaches that are not TDD but could be a lot more trouble than what they are worth ... it's not moral judgement, it's just that they are cost more than they are worth ... the following are simply examples of things that might be ok as learning exercises, but approaches I'd find to be NOT acceptable in serious production and NOT TDD might include: Inspecting quality into your product -- Focusing efforts on developing a proficiency in testing/QA can be problematic, especially if you don't work on the requirements and development side first ... symptom of this include bug triaging where the developers have so many different bugs to deal with it, it is necessary to employ a form of triage -- each development cycle gets worse and worse, programmers work more and more hours, sleep less and less, struggle to keep going in death march until they are consumed. Superstition ... believing in things that you don't understand -- this would involve borrowing code that you believe has been proven or tested from somewhere, e.g. legacy code, a magic code starter wizard or an open source project, and you go forward hacking up a storm of modifications, sliding FaceBook Connect into your the user interface, inventing some new magic features on the fly (e.g. a mashup using the Twitter API, GoogleMaps API and maybe Zappos API), showing off your cool new "product" to a few people and then writing up a simple "specification" and list of "test cases" and turning that over to Mechanical Turk for testing.

    Read the article

  • Refactoring Rspec specs

    - by Steve Weet
    I am trying to cleanup my specs as they are becoming extremely repetitive. I have the following spec describe "Countries API" do it "should render a country list" do co1 = Factory(:country) co2 = Factory(:country) result = invoke :GetCountryList, "empty_auth" result.should be_an_instance_of(Api::GetCountryListReply) result.status.should be_an_instance_of(Api::SoapStatus) result.status.code.should eql 0 result.status.errors.should be_an_instance_of Array result.status.errors.length.should eql 0 result.country_list.should be_an_instance_of Array result.country_list.first.should be_an_instance_of(Api::Country) result.country_list.should have(2).items end it_should_behave_like "All Web Services" it "should render a non-zero status for an invalid request" end The block of code that checks the status will appear in all of my specs for 50-60 APIs. My first thought was to move that to a method and that refactoring certainly makes things much drier as follows :- def status_should_be_valid(status) status.should be_an_instance_of(Api::SoapStatus) status.code.should eql 0 status.errors.should be_an_instance_of Array status.errors.length.should eql 0 end describe "Countries API" do it "should render a country list" do co1 = Factory(:country) co2 = Factory(:country) result = invoke :GetCountryList, "empty_auth" result.should be_an_instance_of(Api::GetCountryListReply) status_should_be_valid(result.status) result.country_list.should be_an_instance_of Array result.country_list.first.should be_an_instance_of(Api::Country) result.country_list.should have(2).items end end This works however I can not help feeling that this is not the "right" way to do it and I should be using shared specs, however looking at the method for defining shared specs I can not easily see how I would refactor this example to use a shared spec. How would I do this with shared specs and without having to re-run the relatively costly block at the beginning namely co1 = Factory(:country) co2 = Factory(:country) result = invoke :GetCountryList, "empty_auth"

    Read the article

  • Refactoring huge if ( ... instanceof ...)

    - by Chris
    I'm currently trying to refactor a part of a project that looks like this: Many classes B extends A; C extends A; D extends C; E extends B; F extends A; ... And somewhere in the code: if (x instanceof B){ B n = (B) x; ... }else if (x instanceof C){ C n = (C) x; ... }else if (x instanceof D){ D n = (D) x; ... }else if (x instanceof E){ E n = (E) x; ... }else if (x instanceof G){ G n = (G) x; ... }... Above if-construct currently sits in a function with a CC of 19. Now my question is: Can I split this if-construct up in mutliple functions and let Java's OO do the magic? Or are there any catches I have to look out for? My idea: private void oopMagic(C obj){ ... Do the stuff from the if(x instanceof C) here} private void oopMagic(D obj){ ... Do the stuff from the if(x instanceof D) here} private void oopMagic(E obj){ ... Do the stuff from the if(x instanceof E) here} .... and instead of the huge if: oopMagic(x);

    Read the article

  • How do you deal with breaking changes in a Rails migration?

    - by Adam Lassek
    Let's say I'm starting out with this model: class Location < ActiveRecord::Base attr_accessible :company_name, :location_name end Now I want to refactor one of the values into an associated model. class CreateCompanies < ActiveRecord::Migration def self.up create_table :companies do |t| t.string :name, :null => false t.timestamps end add_column :locations, :company_id, :integer, :null => false end def self.down drop_table :companies remove_column :locations, :company_id end end class Location < ActiveRecord::Base attr_accessible :location_name belongs_to :company end class Company < ActiveRecord::Base has_many :locations end This all works fine during development, since I'm doing everything a step at a time; but if I try deploying this to my staging environment, I run into trouble. The problem is that since my code has already changed to reflect the migration, it causes the environment to crash when it attempts to run the migration. Has anyone else dealt with this problem? Am I resigned to splitting my deployment up into multiple steps?

    Read the article

  • Catch test case order [on hold]

    - by DeadMG
    Can I guarantee the order of execution with multiple TEST_CASEs with Catch? I am testing some code using LLVM, and they have some despicable global state that I need to explicitly initialize. Right now I have one test case that's like this: TEST_CASE("", "") { // Initialize really shitty LLVM global variables. llvm::InitializeAllTargets(); llvm::InitializeAllTargetMCs(); llvm::InitializeAllAsmPrinters(); llvm::InitializeNativeTarget(); llvm::InitializeAllAsmParsers(); // Some per-test setup I can make into its own function CHECK_NOTHROW(Compile(...)); CHECK_NOTHROW(Compile(...)); CHECK_NOTHROW(Compile(...)); CHECK_NOTHROW(Compile(...)); CHECK_NOTHROW(Compile(...)); CHECK_NOTHROW(Compile(...)); CHECK_NOTHROW(Compile(...)); CHECK_NOTHROW(Compile(...)); CHECK_NOTHROW(Compile(...)); CHECK_NOTHROW(Compile...)); CHECK_NOTHROW(Interpret(...)); CHECK_THROWS(Compile(...)); CHECK_THROWS(Compile(...)); } What I want is to refactor it into three TEST_CASE, one for tests that should pass compilation, one for tests that should fail, and -one for tests that should pass interpretation (and in the future, further such divisions, perhaps). But I can't simply move the test contents into another TEST_CASE because if that TEST_CASE is called before the one that sets up the inconvenient globals, then they won't be initialized and the testing will spuriously fail.

    Read the article

  • POP Forums v9 Beta 1 for ASP.NET MVC 3 posted to CodePlex!

    - by Jeff
    As promised, I posted a beta build of my forum app for ASP.NET MVC 3. Get the new goodies here: http://popforums.codeplex.com/releases/view/58228 This is the first beta for the ASP.NET MVC 3 version of POP Forums. It is nearly feature complete, and ready for testing and feedback. For previous release notes, look here, here and here.Check out the live preview: http://preview.popforums.com/ForumsSetup instructions are on the home page of this project. The new hotness in the beta, or what has been done since the last preview: All views converted to use Razor E-mail subscription/notification of new posts New post indicators/mark read buttons Permalinks to posts Jump to newest post (from new post indicators) Recent topics Favorite topics Moderator functions for topics (pin/close/delete, plus move and rename) Search, ported from v8. Not a ton of optimization here, or new unit testing, but the old version worked pretty well User posts (topics the user posted in) Forgot password Vanity items (signatures and avatars) Hide vanity items per user preference Some minor data caching where appropriate A little bit of UI refinement Lots-o-bug fixes Lots-o-unit tests What's next? The plan between now and the next beta is as follows: Continue working through features/tasks, and fix bugs as they're reported Integrate the forum into a real, production site Refine the UI Refactor as much as possible... the code organization is not entirely logical in some places After the second beta, a release candidate will follow, with a real "final" release after that. Subsequent releases should come relatively frequently and without a lot of risk. The trick in building this thing has been that it mostly tossed the previous WebForms version, which was all full of crusties. The time table for this is a little harder to pin down, as day jobs and families will have their effect. Other notes Refactoring will be a priority. As the features of MVC have evolved, so have my desires to use it in a fashion that makes things clear and easy to follow. I don't even know if anyone will ever start mucking around in the code, but on the off chance they do, I'd like what they find to not suck. Other nice-to-haves are builds to target Windows Azure and SQL CE. A nice setup UI would be super too. I think the ASP.NET MVC world has gone long enough without a decent forum.The biggest challenge that I've found is making the forum something that can be dropped in any app. While it does rope its views into an area, areas are mostly just routing details. I haven't thought of a clever way yet to limit dependency injection, for example, to just the forum bits. I mean, everyone should be using Ninject, but how realistic is that? ;)How much time and effort should you spend on POP Forums in its current state? Change is inevitable, but at this point I'm reasonably committed to not changing the database schema. I really think it will stay as-is. All bets are off for the various interfaces throughout the app, but the data should generally resist change. It's not even that different from v8, which was one of the original goals because I didn't want to rewrite SQL or introduce a new ORM or whatever. My point is that if you wanted to build a site around this today, even though it's not entirely functional, I think it's low risk in terms of data loss. I can't vouch for whether or not you know what you're doing.I've been having some chats with people lately about quoting posts, and honestly there has to be something better and straight forward. That continues to be a holy grail of mine, and some day, I hope to find it.Enjoy... it's starting to feel more real every day!

    Read the article

  • Multiplayer / Networking options for a 2D game with physics

    - by lahmas
    Summary: My 50% finished 2D sidescroller with Box2D as physics engine should have multiplayer support in the final version. However, the current code is just a singleplayer game. What should I do now? And more important, how should I implement multiplayer and combine it with singleplayer? Is it a bad idea to code the singleplayer mode separated from multiplayer mode (like Notch did it with Minecraft)? The performance in singleplayer should be as good as possible (Simulating physics with using a loopback server to implement singleplayer mode would be a problem there) Full background / questions: I'm working on a relatively large 2D game project in C++, with physics as a core element of it. (I use Box2D for that) The finished game should have full multiplayer support, however I made the mistake that I didn't plan the networking part properly and basically worked on a singleplayer game until now. I thought that multiplayer support could be added to the almost finished singleplayer game in a relatively easy and clear way, but apparently, from what I have read this is wrong. I even read that a multiplayer game should be programmed as one from the beginning, with the singleplayer mode actually just consisting of hosting an invisible local server and connecting to it via loopback. (I found out that most FPS game engines do it that way, an example would be Source) So here I am, with my half finished 2D sidescroller game, and I don't really know how to go on. Simply continueing to work on the singleplayer / client seems useless to me now, as I'd have to recode and refactor even more later. First, a general question to anybody who possibly found himself in a situation like this: How should I proceed? Then, the more specific one - I have been trying to find out how I can approach the networking part for my game: (Possible solutions:) Invisible / loopback server for singleplayer This would have the advantage that there basically is no difference between singleplayer and multiplayer mode. Not much additional code would be needed. A big disadvantage: Performance and other limitations in singleplayer. There would be two physics simulations running. One for the client and one for the loopback server. Even if you work around by providing a direct path for the data from the loopback server, through direct communcation by the threads for example, the singleplayer would be limited. This is a problem because people should be allowed to play around with masses of objects at once. Separated singleplayer / Multiplayer mode There would be no server involved in singleplayer mode. I'm not really sure how this would work. But at least I think that there would be a lot of additional work, because all of the singleplayer features would have to be re-implemented or glued to multiplayer mode. Multiplayer mode as a module for singleplayer This is merely a quick thought I had. Multiplayer could consist of a singleplayer game, with an additional networking module loaded and connected to a server, which sends and receives data and updates the singleplayer world. In the retrospective, I regret not having planned the multiplayer mode earlier. I'm really stuck at this point and I hope that somebody here is able to help me!

    Read the article

  • Best Practices for Handing over Legacy Code

    - by PersonalNexus
    In a couple of months a colleague will be moving on to a new project and I will be inheriting one of his projects. To prepare, I have already ordered Michael Feathers' Working Effectively with Legacy Code. But this books as well as most questions on legacy code I found so far are concerned with the case of inheriting code as-is. But in this case I actually have access to the original developer and we do have some time for an orderly hand-over. Some background on the piece of code I will be inheriting: It's functioning: There are no known bugs, but as performance requirements keep going up, some optimizations will become necessary in the not too distant future. Undocumented: There is pretty much zero documentation at the method and class level. What the code is supposed to do at a higher level, though, is well-understood, because I have been writing against its API (as a black-box) for years. Only higher-level integration tests: There are only integration tests testing proper interaction with other components via the API (again, black-box). Very low-level, optimized for speed: Because this code is central to an entire system of applications, a lot of it has been optimized several times over the years and is extremely low-level (one part has its own memory manager for certain structs/records). Concurrent and lock-free: While I am very familiar with concurrent and lock-free programming and have actually contributed a few pieces to this code, this adds another layer of complexity. Large codebase: This particular project is more than ten thousand lines of code, so there is no way I will be able to have everything explained to me. Written in Delphi: I'm just going to put this out there, although I don't believe the language to be germane to the question, as I believe this type of problem to be language-agnostic. I was wondering how the time until his departure would best be spent. Here are a couple of ideas: Get everything to build on my machine: Even though everything should be checked into source code control, who hasn't forgotten to check in a file once in a while, so this should probably be the first order of business. More tests: While I would like more class-level unit tests so that when I will be making changes, any bugs I introduce can be caught early on, the code as it is now is not testable (huge classes, long methods, too many mutual dependencies). What to document: I think for starters it would be best to focus documentation on those areas in the code that would otherwise be difficult to understand e.g. because of their low-level/highly optimized nature. I am afraid there are a couple of things in there that might look ugly and in need of refactoring/rewriting, but are actually optimizations that have been out in there for a good reason that I might miss (cf. Joel Spolsky, Things You Should Never Do, Part I) How to document: I think some class diagrams of the architecture and sequence diagrams of critical functions accompanied by some prose would be best. Who to document: I was wondering what would be better, to have him write the documentation or have him explain it to me, so I can write the documentation. I am afraid, that things that are obvious to him but not me would otherwise not be covered properly. Refactoring using pair-programming: This might not be possible to do due to time constraints, but maybe I could refactor some of his code to make it more maintainable while he was still around to provide input on why things are the way they are. Please comment on and add to this. Since there isn't enough time to do all of this, I am particularly interested in how you would prioritize.

    Read the article

  • Java Hint in NetBeans for Identifying JOptionPanes

    - by Geertjan
    I tend to have "JOptionPane.showMessageDialogs" scattered through my code, for debugging purposes. Now I have a way to identify all of them and remove them one by one, since some of them are there for users of the application so shouldn't be removed, via the Refactoring window: Identifying instances of code that I'm interested in is really trivial: import org.netbeans.spi.editor.hints.ErrorDescription; import org.netbeans.spi.java.hints.ConstraintVariableType; import org.netbeans.spi.java.hints.ErrorDescriptionFactory; import org.netbeans.spi.java.hints.Hint; import org.netbeans.spi.java.hints.HintContext; import org.netbeans.spi.java.hints.TriggerPattern; import org.openide.util.NbBundle.Messages; @Hint( displayName = "#DN_ShowMessageDialogChecker", description = "#DESC_ShowMessageDialogChecker", category = "general") @Messages({ "DN_ShowMessageDialogChecker=Found \"ShowMessageDialog\"", "DESC_ShowMessageDialogChecker=Checks for JOptionPane.showMes" }) public class ShowMessageDialogChecker { @TriggerPattern(value = "$1.showMessageDialog", constraints = @ConstraintVariableType(variable = "$1", type = "javax.swing.JOptionPane")) @Messages("ERR_ShowMessageDialogChecker=Are you sure you need this statement?") public static ErrorDescription computeWarning(HintContext ctx) { return ErrorDescriptionFactory.forName( ctx, ctx.getPath(), Bundle.ERR_ShowMessageDialogChecker()); } } Stick the above class, which seriously isn't much code at all, in a module and run it, with this result: Bit trickier to do the fix, i.e., add a bit of code to let the user remove the statement, but I looked in the NetBeans sources and used the System.out fix, which does the same thing:  import com.sun.source.tree.BlockTree; import com.sun.source.tree.StatementTree; import com.sun.source.util.TreePath; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import org.netbeans.api.java.source.CompilationInfo; import org.netbeans.api.java.source.WorkingCopy; import org.netbeans.spi.editor.hints.ErrorDescription; import org.netbeans.spi.editor.hints.Fix; import org.netbeans.spi.java.hints.ConstraintVariableType; import org.netbeans.spi.java.hints.ErrorDescriptionFactory; import org.netbeans.spi.java.hints.Hint; import org.netbeans.spi.java.hints.HintContext; import org.netbeans.spi.java.hints.JavaFix; import org.netbeans.spi.java.hints.TriggerPattern; import org.openide.util.NbBundle.Messages; @Hint( displayName = "#DN_ShowMessageDialogChecker", description = "#DESC_ShowMessageDialogChecker", category = "general") @Messages({ "DN_ShowMessageDialogChecker=Found \"ShowMessageDialog\"", "DESC_ShowMessageDialogChecker=Checks for JOptionPane.showMes" }) public class ShowMessageDialogChecker { @TriggerPattern(value = "$1.showMessageDialog", constraints = @ConstraintVariableType(variable = "$1", type = "javax.swing.JOptionPane")) @Messages("ERR_ShowMessageDialogChecker=Are you sure you need this statement?") public static ErrorDescription computeWarning(HintContext ctx) { Fix fix = new FixImpl(ctx.getInfo(), ctx.getPath()).toEditorFix(); return ErrorDescriptionFactory.forName( ctx, ctx.getPath(), Bundle.ERR_ShowMessageDialogChecker(), fix); } private static final class FixImpl extends JavaFix { public FixImpl(CompilationInfo info, TreePath tp) { super(info, tp); } @Override @Messages("FIX_ShowMessageDialogChecker=Remove the statement") protected String getText() { return Bundle.FIX_ShowMessageDialogChecker(); } @Override protected void performRewrite(TransformationContext tc) throws Exception { WorkingCopy wc = tc.getWorkingCopy(); TreePath statementPath = tc.getPath(); TreePath blockPath = tc.getPath().getParentPath(); while (!(blockPath.getLeaf() instanceof BlockTree)) { statementPath = blockPath; blockPath = blockPath.getParentPath(); if (blockPath == null) { return; } } BlockTree blockTree = (BlockTree) blockPath.getLeaf(); List<? extends StatementTree> statements = blockTree.getStatements(); List<StatementTree> newStatements = new ArrayList<StatementTree>(); for (Iterator<? extends StatementTree> it = statements.iterator(); it.hasNext();) { StatementTree statement = it.next(); if (statement != statementPath.getLeaf()) { newStatements.add(statement); } } BlockTree newBlockTree = wc.getTreeMaker().Block(newStatements, blockTree.isStatic()); wc.rewrite(blockTree, newBlockTree); } } } Aside from now being able to use "Inspect & Refactor" to identify and fix all instances of JOptionPane.showMessageDialog at the same time, you can also do the fixes per instance within the editor:

    Read the article

  • The theory of evolution applied to software

    - by Michel Grootjans
    I recently realized the many parallels you can draw between the theory of evolution and evolving software. Evolution is not the proverbial million monkeys typing on a million typewriters, where one of them comes up with the complete works of Shakespeare. We would have noticed by now, since the proverbial monkeys are now blogging on the Internet ;-) One of the main ideas of the theory of evolution is the balance between random mutations and natural selection. Random mutations happen all the time: millions of mutations over millions of years. Most of them are totally useless. Some of them are beneficial to the evolved species. Natural selection favors the beneficially mutated species. Less beneficial mutations die off. The mutated rabbit doesn't have to be faster than the fox. It just has to be faster than the other rabbits.   Theory of evolution Evolving software Random mutations happen all the time. Most of these mutations are so bad, the new species dies off, or cannot reproduce. Developers write new code all the time. New ideas come up during the act of writing software. The really bad ones don't get past the stage of idea. The bad ones don't get committed to source control. Natural selection favors the beneficial mutated species Good ideas and new code gets discussed in group during informal peer review. Less than good code gets refactored. Enhanced code makes it more readable, maintainable... A good set of traits makes the species superior to others. It becomes widespread A good design tends to make it easier to add new features, easier to understand the current implementations, easier to optimize for performance...thus superior. The best designs get carried over from project to project. They appear in blogs, articles and books about principles, patterns and practices.   Of course the act of writing software is deliberate. This can hardly be called random mutations. Though it sometimes might seem that code evolves through a will of its own ;-) Does this mean that evolving software (evolution) is better than a big design up front (creationism)? Not necessarily. It's a false idea to think that a project starts from scratch and everything evolves from there. Everyone carries his experience of what works and what doesn't. Up front design is necessary, but is best kept simple and minimal, just enough to get you started. Let the good experiences and ideas help to drive the process, whether they come from you or from others, from past experience or from the most junior developer on your team. Once again, balance is the keyword. Balance design up front with evolution on a daily basis. How do you know what balance is right? Through your own experience of what worked and what didn't (here's evolution again). Notes: The evolution of software can quickly degenerate without discipline. TDD is a discipline that leaves little to chance on that part. Write your test to describe the new behavior. Write just enough code to make it behave as specified. Refactor to evolve the code to a higher standard. The responsibility of good design rests continuously on each developers' shoulders. Promiscuous pair programming helps quickly spreading the design to the whole team.

    Read the article

  • How should an object that uses composition set its composed components?

    - by Casey
    After struggling with various problems and reading up on component-based systems and reading Bob Nystrom's excellent book "Game Programming Patterns" and in particular the chapter on Components I determined that this is a horrible idea: //Class intended to be inherited by all objects. Engine uses Objects exclusively. class Object : public IUpdatable, public IDrawable { public: Object(); Object(const Object& other); Object& operator=(const Object& rhs); virtual ~Object() =0; virtual void SetBody(const RigidBodyDef& body); virtual const RigidBody* GetBody() const; virtual RigidBody* GetBody(); //Inherited from IUpdatable virtual void Update(double deltaTime); //Inherited from IDrawable virtual void Draw(BITMAP* dest); protected: private: }; I'm attempting to refactor it into a more manageable system. Mr. Nystrom uses the constructor to set the individual components; CHANGING these components at run-time is impossible. It's intended to be derived and be used in derivative classes or factory methods where their constructors do not change at run-time. i.e. his Bjorne object is just a call to a factory method with a specific call to the GameObject constructor. Is this a good idea? Should the object have a default constructor and setters to facilitate run-time changes or no default constructor without setters and instead use a factory method? Given: class Object { public: //...See below for constructor implementation concerns. Object(const Object& other); Object& operator=(const Object& rhs); virtual ~Object() =0; //See below for Setter concerns IUpdatable* GetUpdater(); IDrawable* GetRenderer(); protected: IUpdatable* _updater; IDrawable* _renderer; private: }; Should the components be read-only and passed in to the constructor via: class Object { public: //No default constructor. Object(IUpdatable* updater, IDrawable* renderer); //...remainder is same as above... }; or Should a default constructor be provided and then the components can be set at run-time? class Object { public: Object(); //... SetUpdater(IUpdater* updater); SetRenderer(IDrawable* renderer); //...remainder is same as above... }; or both? class Object { public: Object(); Object(IUpdater* updater, IDrawable* renderer); //... SetUpdater(IUpdater* updater); SetRenderer(IDrawable* renderer); //...remainder is same as above... };

    Read the article

  • Workflow versioning

    - by Nitra
    I believe I have a fundamental misunderstanding when it comes to workflow engines which I would appreciate if you could help me sort out. I'm not sure if my misunderstanding is specific to the workflow engine I'm using, or if it's a general misunderstanding. I happen to use Windows Workflow Foundation (WWF). TLDR-version WWF allows you to implement business processes in long-running workflows (think months or even years). When started, the workflows can't be changed. But what business process can't change at any time? And if a business process changes, wouldn't you want your software to reflect this change for already started 'instances' of the business process? What am I missing? Background In WWF you define a workflow by combining a set of activites. There are different types of activities - some of them are for flow control, such as the IfElseActivity and the WhileActivty while others allows you to perform actual tasks, such as the CodeActivity wich allows you to run .NET code and the InvokeWebServiceActivity which allows you to call web services. The activites are combined to a workflow using a visual designer. You pretty much drag-and-drop activities from a toolbox to a designer area and connect the activites to each other. The workflow and activities have input paramters, output parameters and variables. We have a single workflow which sometimes runs in a matter of a few days, but it may run for 5-6 months. WWF takes care of persisting the workflow state (what activity are we currently executing, what are the variable values and so on). So far I think WWF makes sense. Some people will prefer to implement a software representation of a business process using a visual designer over writing all of it in code. So what's the issue then? What I don't really get is the following: WWF is designed to take care of long-running workflows. But at the same time, WWF has no built-in functionality which allows you to modify the running workflows. So if you model a business process using a workflow and run that for 6 months, you better hope that the business process does not change. Because if it do, you'll have to have multiple versions of the workflow executing at the same time. This seems like a fundamental design mistake to me, but at the same time it seems more likely that I've misunderstood something. For us, this has had some real-world effects: We release new versions every month, but some workflows may run for a year. This means that we have several versions of the workflow running in parallell, in other words several versions of the business logics. This is the same as having many differnt versions of your code running in production in the same system at the same time, which becomes a bit hard to understand for users. (depending on on whether they clicked a 'Start' button 9 or 10 months ago, the software will behave differently) Our workflow refers to different types of entities and since WWF now has persisted and serialized these we can't really refactor the entities since then existing workflows can't be resumed (deserialization will fail We've received some suggestions on how to handle this When we create a new version of the workflow, cancel all running workflows and create new ones. But in our workflows there's a lot of manual work involved and if we start from scratch a lot of people has to re-do their work. Track what has been done in the workflow and when you create a new one skip activites which have already been executed. I feel that this alternative may work for simple workflows, but it becomes hairy to automatically figure out what activities to skip if there's major refactoring done to a workflow. When we create a new version of the workflow, upgrade old versions using the new WWF 4.5 functionality for upgrading workflows. But then we would have to skip using the visual designer and write code to inject activities in the right places in the workflow. According to MSDN, this upgrade functionality is only intended for minor bug fixes and not larger changes. What am I missing?

    Read the article

  • Broken Views

    - by Ajarn Mark Caldwell
    “SELECT *” isn’t just hazardous to performance, it can actually return blatantly wrong information. There are a number of blog posts and articles out there that actively discourage the use of the SELECT * FROM …syntax.  The two most common explanations that I have seen are: Performance:  The SELECT * syntax will return every column in the table, but frequently you really only need a few of the columns, and so by using SELECT * your are retrieving large volumes of data that you don’t need, but the system has to process, marshal across tiers, and so on.  It would be much more efficient to only select the specific columns that you need. Future-proof:  If you are taking other shortcuts in your code, along with using SELECT *, you are setting yourself up for trouble down the road when enhancements are made to the system.  For example, if you use SELECT * to return results from a table into a DataTable in .NET, and then reference columns positionally (e.g. myDataRow[5]) you could end up with bad data if someone happens to add a column into position 3 and skewing all the remaining columns’ ordinal position.  Or if you use INSERT…SELECT * then you will likely run into errors when a new column is added to the source table in any position. And if you use SELECT * in the definition of a view, you will run into a variation of the future-proof problem mentioned above.  One of the guys on my team, Mike Byther, ran across this in a project we were doing, but fortunately he caught it while we were still in development.  I asked him to put together a test to prove that this was related to the use of SELECT * and not some other anomaly.  I’ll walk you through the test script so you can see for yourself what happens. We are going to create a table and two views that are based on that table, one of them uses SELECT * and the other explicitly lists the column names.  The script to create these objects is listed below. IF OBJECT_ID('testtab') IS NOT NULL DROP TABLE testtabgoIF OBJECT_ID('testtab_vw') IS NOT NULL DROP VIEW testtab_vwgo IF OBJECT_ID('testtab_vw_named') IS NOT NULL DROP VIEW testtab_vw_namedgo CREATE TABLE testtab (col1 NVARCHAR(5) null, col2 NVARCHAR(5) null)INSERT INTO testtab(col1, col2)VALUES ('A','B'), ('A','B')GOCREATE VIEW testtab_vw AS SELECT * FROM testtabGOCREATE VIEW testtab_vw_named AS SELECT col1, col2 FROM testtabgo Now, to prove that the two views currently return equivalent results, select from them. SELECT 'star', col1, col2 FROM testtab_vwSELECT 'named', col1, col2 FROM testtab_vw_named OK, so far, so good.  Now, what happens if someone makes a change to the definition of the underlying table, and that change results in a new column being inserted between the two existing columns?  (Side note, I normally prefer to append new columns to the end of the table definition, but some people like to keep their columns alphabetized, and for clarity for later people reviewing the schema, it may make sense to group certain columns together.  Whatever the reason, it sometimes happens, and you need to protect yourself and your code from the repercussions.) DROP TABLE testtabgoCREATE TABLE testtab (col1 NVARCHAR(5) null, col3 NVARCHAR(5) NULL, col2 NVARCHAR(5) null)INSERT INTO testtab(col1, col3, col2)VALUES ('A','C','B'), ('A','C','B')goSELECT 'star', col1, col2 FROM testtab_vwSELECT 'named', col1, col2 FROM testtab_vw_named I would have expected that the view using SELECT * in its definition would essentially pass-through the column name and still retrieve the correct data, but that is not what happens.  When you run our two select statements again, you see that the View that is based on SELECT * actually retrieves the data based on the ordinal position of the columns at the time that the view was created.  Sure, one work-around is to recreate the View, but you can’t really count on other developers to know the dependencies you have built-in, and they won’t necessarily recreate the view when they refactor the table. I am sure that there are reasons and justifications for why Views behave this way, but I find it particularly disturbing that you can have code asking for col2, but actually be receiving data from col3.  By the way, for the record, this entire scenario and accompanying test script apply to SQL Server 2008 R2 with Service Pack 1. So, let the developer beware…know what assumptions are in effect around your code, and keep on discouraging people from using SELECT * syntax in anything but the simplest of ad-hoc queries. And of course, let’s clean up after ourselves.  To eliminate the database objects created during this test, run the following commands. DROP TABLE testtabDROP VIEW testtab_vwDROP VIEW testtab_vw_named

    Read the article

  • MVC Portable Areas Enhancement &ndash; Embedded Resource Controller

    - by Steve Michelotti
    MvcContrib contains a feature called Portable Areas which I’ve recently blogged about. In short, portable areas provide a way to distribute MVC binary components as simple .NET assemblies where the aspx/ascx files are actually compiled into the assembly as embedded resources. This is an extremely cool feature but once you start building robust portable areas, you’ll also want to be able to access other external files like css and javascript.  After my recent post suggesting portable areas be expanded to include other embedded resources, Eric Hexter asked me if I’d like to contribute the code to MvcContrib (which of course I did!). Embedded resources are stored in a case-sensitive way in .NET assemblies and the existing embedded view engine inside MvcContrib already took this into account. Obviously, we’d want the same case sensitivity handling to be taken into account for any embedded resource so my job consisted of 1) adding the Embedded Resource Controller, and 2) a little refactor to extract the logic that deals with embedded resources so that the embedded view engine and the embedded resource controller could both leverage it and, therefore, keep the code DRY. The embedded resource controller targets these scenarios: External image files that are referenced in an <img> tag External files referenced like css or JavaScript files Image files referenced inside css files Embedded Resources Walkthrough This post will describe a walkthrough of using the embedded resource controller in your portable areas to include the scenarios outlined above. I will build a trivial “Quick Links” widget to illustrate the concepts. The portable area registration is the starting point for all portable areas. The MvcContrib.PortableAreas.EmbeddedResourceController is optional functionality – you must opt-in if you want to use it.  To do this, you simply “register” it by providing a route in your area registration that uses it like this: 1: context.MapRoute("ResourceRoute", "quicklinks/resource/{resourceName}", 2: new { controller = "EmbeddedResource", action = "Index" }, 3: new string[] { "MvcContrib.PortableAreas" }); First, notice that I can specify any route I want (e.g., “quicklinks/resources/…”).  Second, notice that I need to include the “MvcContrib.PortableAreas” namespace as the fourth parameter so that the framework is able to find the EmbeddedResourceController at runtime. The handling of embedded views and embedded resources have now been merged.  Therefore, the call to: 1: RegisterTheViewsInTheEmmeddedViewEngine(GetType()); has now been removed (breaking change).  It has been replaced with: 1: RegisterAreaEmbeddedResources(); Other than that, the portable area registration remains unchanged. The solution structure for the static files in my portable area looks like this: I’ve got a css file in a folder called “Content” as well as a couple of image files in a folder called “images”. To reference these in my aspx/ascx code, all of have to do is this: 1: <link href="<%= Url.Resource("Content.QuickLinks.css") %>" rel="stylesheet" type="text/css" /> 2: <img src="<%= Url.Resource("images.globe.png") %>" /> This results in the following HTML mark up: 1: <link href="/quicklinks/resource/Content.QuickLinks.css" rel="stylesheet" type="text/css" /> 2: <img src="/quicklinks/resource/images.globe.png" /> The Url.Resource() method is now included in MvcContrib as well. Make sure you import the “MvcContrib” namespace in your views. Next, I have to following html to render the quick links: 1: <ul class="links"> 2: <li><a href="http://www.google.com">Google</a></li> 3: <li><a href="http://www.bing.com">Bing</a></li> 4: <li><a href="http://www.yahoo.com">Yahoo</a></li> 5: </ul> Notice the <ul> tag has a class called “links”. This is defined inside my QuickLinks.css file and looks like this: 1: ul.links li 2: { 3: background: url(/quicklinks/resource/images.navigation.png) left 4px no-repeat; 4: padding-left: 20px; 5: margin-bottom: 4px; 6: } On line 3 we’re able to refer to the url for the background property. As a final note, although we already have complete control over the location of the embedded resources inside the assembly, what if we also want control over the physical URL routes as well. This point was raised by John Nelson in this post. This has been taken into account as well. For example, suppose you want your physical url to look like this: 1: <img src="/quicklinks/images/globe.png" /> instead of the same corresponding URL shown above (i.e., “/quicklinks/resources/images.globe.png”). You can do this easily by specifying another route for it which includes a “resourcePath” parameter that is pre-pended. Here is the complete code for the area registration with the custom route for the images shown on lines 9-11: 1: public class QuickLinksRegistration : PortableAreaRegistration 2: { 3: public override void RegisterArea(System.Web.Mvc.AreaRegistrationContext context, IApplicationBus bus) 4: { 5: context.MapRoute("ResourceRoute", "quicklinks/resource/{resourceName}", 6: new { controller = "EmbeddedResource", action = "Index" }, 7: new string[] { "MvcContrib.PortableAreas" }); 8:   9: context.MapRoute("ResourceImageRoute", "quicklinks/images/{resourceName}", 10: new { controller = "EmbeddedResource", action = "Index", resourcePath = "images" }, 11: new string[] { "MvcContrib.PortableAreas" }); 12:   13: context.MapRoute("quicklink", "quicklinks/{controller}/{action}", 14: new {controller = "links", action = "index"}); 15:   16: this.RegisterAreaEmbeddedResources(); 17: } 18:   19: public override string AreaName 20: { 21: get 22: { 23: return "QuickLinks"; 24: } 25: } 26: } The Quick Links portable area results in the following requests (including custom route formats): The complete code for this post is now included in the Portable Areas sample solution in the latest MvcContrib source code. You can get the latest code now.  Portable Areas open up exciting new possibilities for MVC development!

    Read the article

  • Your thoughts on Best Practices for Scientific Computing?

    - by John Smith
    A recent paper by Wilson et al (2014) pointed out 24 Best Practices for scientific programming. It's worth to have a look. I would like to hear opinions about these points from experienced programmers in scientific data analysis. Do you think these advices are helpful and practical? Or are they good only in an ideal world? Wilson G, Aruliah DA, Brown CT, Chue Hong NP, Davis M, Guy RT, Haddock SHD, Huff KD, Mitchell IM, Plumbley MD, Waugh B, White EP, Wilson P (2014) Best Practices for Scientific Computing. PLoS Biol 12:e1001745. http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001745 Box 1. Summary of Best Practices Write programs for people, not computers. (a) A program should not require its readers to hold more than a handful of facts in memory at once. (b) Make names consistent, distinctive, and meaningful. (c) Make code style and formatting consistent. Let the computer do the work. (a) Make the computer repeat tasks. (b) Save recent commands in a file for re-use. (c) Use a build tool to automate workflows. Make incremental changes. (a) Work in small steps with frequent feedback and course correction. (b) Use a version control system. (c) Put everything that has been created manually in version control. Don’t repeat yourself (or others). (a) Every piece of data must have a single authoritative representation in the system. (b) Modularize code rather than copying and pasting. (c) Re-use code instead of rewriting it. Plan for mistakes. (a) Add assertions to programs to check their operation. (b) Use an off-the-shelf unit testing library. (c) Turn bugs into test cases. (d) Use a symbolic debugger. Optimize software only after it works correctly. (a) Use a profiler to identify bottlenecks. (b) Write code in the highest-level language possible. Document design and purpose, not mechanics. (a) Document interfaces and reasons, not implementations. (b) Refactor code in preference to explaining how it works. (c) Embed the documentation for a piece of software in that software. Collaborate. (a) Use pre-merge code reviews. (b) Use pair programming when bringing someone new up to speed and when tackling particularly tricky problems. (c) Use an issue tracking tool. I'm relatively new to serious programming for scientific data analysis. When I tried to write code for pilot analyses of some of my data last year, I encountered tremendous amount of bugs both in my code and data. Bugs and errors had been around me all the time, but this time it was somewhat overwhelming. I managed to crunch the numbers at last, but I thought I couldn't put up with this mess any longer. Some actions must be taken. Without a sophisticated guide like the article above, I started to adopt "defensive style" of programming since then. A book titled "The Art of Readable Code" helped me a lot. I deployed meticulous input validations or assertions for every function, renamed a lot of variables and functions for better readability, and extracted many subroutines as reusable functions. Recently, I introduced Git and SourceTree for version control. At the moment, because my co-workers are much more reluctant about these issues, the collaboration practices (8a,b,c) have not been introduced. Actually, as the authors admitted, because all of these practices take some amount of time and effort to introduce, it may be generally hard to persuade your reluctant collaborators to comply them. I think I'm asking your opinions because I still suffer from many bugs despite all my effort on many of these practices. Bug fix may be, or should be, faster than before, but I couldn't really measure the improvement. Moreover, much of my time has been invested on defence, meaning that I haven't actually done much data analysis (offence) these days. Where is the point I should stop at in terms of productivity? I've already deployed: 1a,b,c, 2a, 3a,b,c, 4b,c, 5a,d, 6a,b, 7a,7b I'm about to have a go at: 5b,c Not yet: 2b,c, 4a, 7c, 8a,b,c (I could not really see the advantage of using GNU make (2c) for my purpose. Could anyone tell me how it helps my work with MATLAB?)

    Read the article

  • Test-Drive ASP.NET MVC Review

    - by Ben Griswold
    A few years back I started dallying with test-driven development, but I never fully committed to the practice. This wasn’t because I didn’t believe in the value of TDD; it was more a matter of not completely understanding how to incorporate “test first” into my everyday development. Back in my web forms days, I could point fingers at the framework for my ignorance and laziness. After all, web forms weren’t exactly designed for testability so who could blame me for not embracing TDD in those conditions, right? But when I switched to ASP.NET MVC and quickly found myself fresh out of excuses and it became instantly clear that it was time to get my head around red-green-refactor once and for all or I would regretfully miss out on one of the biggest selling points the new framework had to offer. I have previously written about how I learned ASP.NET MVC. It was primarily hands on learning but I did read a couple of ASP.NET MVC books along the way. The books I read dedicated a chapter or two to TDD and they certainly addressed the benefits of TDD and how MVC was designed with testability in mind, but TDD was merely an afterthought compared to, well, teaching one how to code the model, view and controller. This approach made some sense, and I learned a bunch about MVC from those books, but when it came to TDD the books were just a teaser and an opportunity missed.  But then I got lucky – Jonathan McCracken contacted me and asked if I’d review his book, Test-Drive ASP.NET MVC, and it was just what I needed to get over the TDD hump. As the title suggests, Test-Drive ASP.NET MVC takes a different approach to learning MVC as it focuses on testing right from the very start. McCracken wastes no time and swiftly familiarizes us with the framework by building out a trivial Quote-O-Matic application and then dedicates the better part of his book to testing first – first by explaining TDD and then coding a full-featured Getting Organized application inspired by David Allen’s popular book, Getting Things Done. If you are a learn-by-example kind of coder (like me), you will instantly appreciate and enjoy McCracken’s style – its fast-moving, pragmatic and focused on only the most relevant information required to get you going with ASP.NET MVC and TDD. The book continues with the test-first theme but McCracken moves away from the sample application and incorporates other practical skills like persisting models with NHibernate, leveraging Inversion of Control with the IControllerFactory and building a RESTful web service. What I most appreciated about this section was McCracken’s use of and praise for open source libraries like Rhino Mocks, SQLite and StructureMap (to name just a few) and productivity tools like ReSharper, Web Platform Installer and ASP.NET SQL Server Setup Wizard.  McCracken’s emphasis on real world, pragmatic development was clearly demonstrated in every tool choice, straight-forward code block and developer tip. Whether one is already familiar with the tools/tips or not, McCracken’s thought process is easily understood and appreciated. The final section of the book walks the reader through security and deployment – everything from error handling and logging with ELMAH, to ASP.NET Health Monitoring, to using MSBuild with automated builds, to the deployment  of ASP.NET MVC to various web environments. These chapters, like those prior, offer enough information and explanation to simply help you get the job done.  Do I believe Test-Drive ASP.NET MVC will turn you into an expert MVC developer overnight?  Well, no.  I don’t think any book can make that claim.  If that were possible, I think book list prices would skyrocket!  That said, Test-Drive ASP.NET MVC provides a solid foundation and a unique (and dare I say necessary) approach to learning ASP.NET MVC.  Along the way McCracken shares loads of very practical software development tips and references numerous tools and libraries. The bottom line is it’s a great ASP.NET MVC primer – if you’re new to ASP.NET MVC it’s just what you need to get started.  Do I believe Test-Drive ASP.NET MVC will give you everything you need to start employing TDD in your everyday development?  Well, I used to think that learning TDD required a lot of practice and, if you’re lucky enough, the guidance of a mentor or coach.  I used to think that one couldn’t learn TDD from a book alone. Well, I’m still no pro, but I’m testing first now and Jonathan McCracken and his book, Test-Drive ASP.NET MVC, played a big part in making this happen.  If you are an MVC developer and a TDD newb, Test-Drive ASP.NET MVC is just the book for you.

    Read the article

  • Independence Day for Software Components &ndash; Loosening Coupling by Reducing Connascence

    - by Brian Schroer
    Today is Independence Day in the USA, which got me thinking about loosely-coupled “independent” software components. I was reminded of a video I bookmarked quite a while ago of Jim Weirich’s “Grand Unified Theory of Software Design” talk at MountainWest RubyConf 2009. I finally watched that video this morning. I highly recommend it. In the video, Jim talks about software connascence. The dictionary definition of connascence (con-NAY-sense) is: 1. The common birth of two or more at the same time 2. That which is born or produced with another. 3. The act of growing together. The brief Wikipedia page about Connascent Software Components says that: Two software components are connascent if a change in one would require the other to be modified in order to maintain the overall correctness of the system. Connascence is a way to characterize and reason about certain types of complexity in software systems. The term was introduced to the software world in Meilir Page-Jones’ 1996 book “What Every Programmer Should Know About Object-Oriented Design”. The middle third of that book is the author’s proposed graphical notation for describing OO designs. UML became the standard about a year later, so a revised version of the book was published in 1999 as “Fundamentals of Object-Oriented Design in UML”. Weirich says that the third part of the book, in which Page-Jones introduces the concept of connascence “is worth the price of the entire book”. (The price of the entire book, by the way, is not much – I just bought a used copy on Amazon for $1.36, so that was a pretty low-risk investment. I’m looking forward to getting the book and learning about connascence from the original source.) Meanwhile, here’s my summary of Weirich’s summary of Page-Jones writings about connascence: The stronger the form of connascence, the more difficult and costly it is to change the elements in the relationship. Some of the connascence types, ordered from weak to strong are: Connascence of Name Connascence of name is when multiple components must agree on the name of an entity. If you change the name of a method or property, then you need to change all references to that method or property. Duh. Connascence of name is unavoidable, assuming your objects are actually used. My main takeaway about connascence of name is that it emphasizes the importance of giving things good names so you don’t need to go changing them later. Connascence of Type Connascence of type is when multiple components must agree on the type of an entity. I assume this is more of a problem for languages without compilers (especially when used in apps without tests). I know it’s an issue with evil JavaScript type coercion. Connascence of Meaning Connascence of meaning is when multiple components must agree on the meaning of particular values, e.g that “1” means normal customer and “2” means preferred customer. The solution to this is to use constants or enums instead of “magic” strings or numbers, which reduces the coupling by changing the connascence form from “meaning” to “name”. Connascence of Position Connascence of positions is when multiple components must agree on the order of values. This refers to methods with multiple parameters, e.g.: eMailer.Send("[email protected]", "[email protected]", "Your order is complete", "Order completion notification"); The more parameters there are, the stronger the connascence of position is between the component and its callers. In the example above, it’s not immediately clear when reading the code which email addresses are sender and receiver, and which of the final two strings are subject vs. body. Connascence of position could be improved to connascence of type by replacing the parameter list with a struct or class. This “introduce parameter object” refactoring might be overkill for a method with 2 parameters, but would definitely be an improvement for a method with 10 parameters. This points out two “rules” of connascence:  The Rule of Degree: The acceptability of connascence is related to the degree of its occurrence. The Rule of Locality: Stronger forms of connascence are more acceptable if the elements involved are closely related. For example, positional arguments in private methods are less problematic than in public methods. Connascence of Algorithm Connascence of algorithm is when multiple components must agree on a particular algorithm. Be DRY – Don’t Repeat Yourself. If you have “cloned” code in multiple locations, refactor it into a common function.   Those are the “static” forms of connascence. There are also “dynamic” forms, including… Connascence of Execution Connascence of execution is when the order of execution of multiple components is important. Consumers of your class shouldn’t have to know that they have to call an .Initialize method before it’s safe to call a .DoSomething method. Connascence of Timing Connascence of timing is when the timing of the execution of multiple components is important. I’ll have to read up on this one when I get the book, but assume it’s largely about threading. Connascence of Identity Connascence of identity is when multiple components must reference the entity. The example Weirich gives is when you have two instances of the “Bob” Employee class and you call the .RaiseSalary method on one and then the .Pay method on the other does the payment use the updated salary?   Again, this is my summary of a summary, so please be forgiving if I misunderstood anything. Once I get/read the book, I’ll make corrections if necessary and share any other useful information I might learn.   See Also: Gregory Brown: Ruby Best Practices Issue #24: Connascence as a Software Design Metric (That link is failing at the time I write this, so I had to go to the Google cache of the page.)

    Read the article

  • The illusion of Competence

    - by tony_lombardo
    Working as a contractor opened my eyes to the developer food chain.  Even though I had similar experiences earlier in my career, the challenges seemed much more vivid this time through.  I thought I’d share a couple of experiences with you, and the lessons that can be taken from them. Lesson 1: Beware of the “funnel” guy.  The funnel guy is the one who wants you to funnel all thoughts, ideas and code changes through him.  He may say it’s because he wants to avoid conflicts in source control, but the real reason is likely that he wants to hide your contributions.  Here’s an example.  When I finally got access to the code on one of my projects, I was told by the developer that I had to funnel all of my changes through him.  There were 4 of us coding on the project, but only 2 of us working on the UI.  The other 2 were working on a separate application, but part of the overall project.  So I figured, I’ll check it into SVN, he reviews and accepts then merges in.  Not even close.  I didn’t even have checkin rights to SVN, I had to email my changes to the developer so he could check those changes in.  Lesson 2: If you point out flaws in code to someone supposedly ‘higher’ than you in the developer chain, they’re going to get defensive.  My first task on this project was to review the code, familiarize myself with it.  So of course, that’s what I did.  And in familiarizing myself with it, I saw so many bad practices and code smells that I immediately started coming up with solutions to fix it.  Of course, when I reviewed these changes with the developer (guy who originally wrote the code), he smiled and nodded and said, we can’t make those changes now, it’s too destabilizing.  I recommended we create a new branch and start working on refactoring, but branching was a new concept for this guy and he was worried we would somehow break SVN. How about some concrete examples? I started out by recommending we remove NUnit dependency and tests from the application project, and create a separate Unit testing project.  This was met with a little bit of resistance because - “How do I access the private methods?”  As it turned out there weren’t really any private methods that weren’t exposed by public methods, so I quickly calmed this fear. Win 1 Loss 0 Next, I recommended that all of the File IO access be wrapped in Using clauses, or at least properly wrapped in try catch finally.  This recommendation was accepted.. but never implemented. Win 2  Loss 1 Next recommendation was to refactor the command pattern implementation.  The command pattern was implemented, but it wasn’t really necessary for the application.  More over, the fact that we had 100 different command classes, each with it’s own specific command parameters class, made maintenance a huge hassle.  The same code repeated over and over and over.  This recommendation was declined, the code was too fragile and this change would destabilize it.  I couldn’t disagree, though it was the commands themselves in many cases that were fragile. Win 2 Loss 2 Next recommendation was to aid performance (and responsiveness) of the application by using asynchronous service calls.  This on was accepted. Win 2 Loss 3 If you’re paying any attention, you’re wondering why the async service calls was scored as a loss.. Let me explain.  The service call was made using the async pattern.  Followed by a thread.sleep  <facepalm>. Now it’s easy to be harsh on this kind of code, especially if you’re an experienced developer.  But I understood how most of this happened.  One junior guy, working as hard as he can to build his first real world application, with little or no guidance from anyone else.  He had his pattern book and theory of programming to help him, but no real world experience.  He didn’t know how difficult it would be to trace the crashes to the coding issues above, but he will one day.  The part that amazed me was the management position that “this guy should be a team lead, because he’s worked so hard”.  I’m all for rewarding hard work, but when you reward someone by promoting them past the point of their competence, you’re setting yourself and them up for failure.  And that’s lesson 3.  Just because you’ve got a hard worker, doesn’t mean he should be leading a development project.  If you’re a junior guy busting your ass, keep at it.  I encourage you to try new things, but most importantly to learn from your mistakes.  And correct your mistakes.  And if someone else looks at your code and shows you a laundry list of things that should be done differently, don’t take it personally – they’re really trying to help you.  And if you’re a senior guy, working with a junior guy, it’s your duty to point out the flaws in the code.  Even if it does make you the bad guy.  And while I’ve used “guy” above, I mean both men and women.  And in some cases mutant dinosaurs. 

    Read the article

  • Using SQL Source Control with Fortress or Vault &ndash; Part 1

    - by AjarnMark
    I am fanatical when it comes to managing the source code for my company.  Everything that we build (in source form) gets put into our source control management system.  And I’m not just talking about the UI and middle-tier code written in C# and ASP.NET, but also the back-end database stuff, which at times has been a pain.  We even script out our Scheduled Jobs and keep a copy of those under source control. The UI and middle-tier stuff has long been easy to manage as we mostly use Visual Studio which has integration with source control systems built in.  But the SQL code has been a little harder to deal with.  I have been doing this for many years, well before Microsoft came up with Data Dude, so I had already established a methodology that, while not as smooth as VS, nonetheless let me keep things well controlled, and allowed doing my database development in my tool of choice, Query Analyzer in days gone by, and now SQL Server Management Studio.  It just makes sense to me that if I’m going to do database development, let’s use the database tool set.  (Although, I have to admit I was pretty impressed with the demo of Juneau that Don Box did at the PASS Summit this year.)  So as I was saying, I had developed a methodology that worked well for us (and I’ll probably outline in a future post) but it could use some improvement. When Solutions and Projects were first introduced in SQL Management Studio, I thought we were finally going to get our same experience that we have in Visual Studio.  Well, let’s say I was underwhelmed by Version 1 in SQL 2005, and apparently so were enough other people that by the time SQL 2008 came out, Microsoft decided that Solutions and Projects would be deprecated and completely removed from a future version.  So much for that idea. Then I came across SQL Source Control from Red-Gate.  I have used several tools from Red-Gate in the past, including my favorites SQL Compare, SQL Prompt, and SQL Refactor.  SQL Prompt is worth its weight in gold, and the others are great, too.  Earlier this year, we upgraded from our earlier product bundles to the new Developer Bundle, and in the process added SQL Source Control to our collection.  I thought this might really be the golden ticket I was looking for.  But my hopes were quickly dashed when I discovered that it only integrated with Microsoft Team Foundation Server and Subversion as the source code repositories.  We have been using SourceGear’s Vault and Fortress products for years, and I wholeheartedly endorse them.  So I was out of luck for the time being, although there were a number of people voting for Vault/Fortress support on their feedback forum (as did I) so I had hope that maybe next year I could look at it again. But just a couple of weeks ago, I was pleasantly surprised to receive notice in my email that Red-Gate had an Early Access version of SQL Source Control that worked with Vault and Fortress, so I quickly downloaded it and have been putting it through its paces.  So far, I really like what I see, and I have been quite impressed with Red-Gate’s responsiveness when I have contacted them with any issues or concerns that I have had.  I have had several communications with Gyorgy Pocsi at Red-Gate and he has been immensely helpful and responsive. I must say that development with SQL Source Control is very different from what I have been used to.  This post is getting long enough, so I’ll save some of the details for a separate write-up, but the short story is that in my regular mode, it’s all about the script files.  Script files are King and you dare not make a change to the database other than by way of a script file, or you are in deep trouble.  With SQL Source Control, you make your changes to your development database however you like.  I still prefer writing most of my changes in T-SQL, but you can also use any of the GUI functionality of SSMS to make your changes, and SQL Source Control “manages” the script for you.  Basically, when you first link your database to source control, the tool generates scripts for every primary object (tables and their indexes are together in one script, not broken out into separate scripts like DB Projects do) and those scripts are checked into your source control.  So, if you needed to, you could still do a GET from your source control repository and build the database from scratch.  But for the day-to-day work, SQL Source Control uses the same technique as SQL Compare to determine what changes have been made to your development database and how to represent those in your repository scripts.  I think that once I retrain myself to just work in the database and quit worrying about having to find and open the right script file, that this will actually make us more efficient. And for deployment purposes, SQL Source Control integrates with the full SQL Compare utility to produce a synchronization script (or do a live sync).  This is similar in concept to Microsoft’s DACPAC, if you’re familiar with that. If you are not currently keeping your database development efforts under source control, definitely examine this tool.  If you already have a methodology that is working for you, then I still think this is worth a review and comparison to your current approach.  You may find it more efficient.  But remember that the version which integrates with Vault/Fortress is still in pre-release mode, so treat it with a little caution.  I have found it to be fairly stable, but there was one bug that I found which had inconvenient side-effects and could have really been frustrating if I had been running this on my normal active development machine.  However, I can verify that that bug has been fixed in a more recent build version (did I mention Red-Gate’s responsiveness?).

    Read the article

  • Monitoring your WCF Web Apis with AppFabric

    - by cibrax
    The other day, Ron Jacobs made public a template in the Visual Studio Gallery for enabling monitoring capabilities to any existing WCF Http service hosted in Windows AppFabric. I thought it would be a cool idea to reuse some of that for doing the same thing on the new WCF Web Http stack. Windows AppFabric provides a dashboard that you can use to dig into some metrics about the services usage, such as number of calls, errors or information about different events during a service call. Those events not only include information about the WCF pipeline, but also custom events that any developer can inject and make sense for troubleshooting issues.      This monitoring capabilities can be enabled on any specific IIS virtual directory by using the AppFabric configuration tool or adding the following configuration sections to your existing web app, <system.serviceModel> <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" /> <diagnostics etwProviderId="3e99c707-3503-4f33-a62d-2289dfa40d41"> <endToEndTracing propagateActivity="true" messageFlowTracing="true" /> </diagnostics> <behaviors> <serviceBehaviors> <behavior name=""> <etwTracking profileName="EndToEndMonitoring Tracking Profile" /> </behavior> </serviceBehaviors> </behaviors> </system.serviceModel>   <microsoft.applicationServer> <monitoring> <default enabled="true" connectionStringName="ApplicationServerMonitoringConnectionString" monitoringLevel="EndToEndMonitoring" /> </monitoring> </microsoft.applicationServer> Bad news is that none of the configuration above can be easily set on code by using the new configuration model for WCF Web stack.  A good thing is that you easily disable it in the configuration when you no longer need it, and also uses ETW, a general-purpose and high-speed tracing facility provided by the operating system (it’s part of the windows kernel). By adding that configuration section, AppFabric will start monitoring your service automatically and providing some basic event information about the service calls. You need some custom code for injecting custom events in the monitoring data. What I did here is to copy and refactor the “WCFUserEventProvider” class provided as sample in the Ron’s template to make it more TDD friendly when using IoC. I created a simple interface “ILogger” that any service (or resource) can use to inject custom events or monitoring information in the AppFabric database. public interface ILogger { bool WriteError(string name, string format, params object[] args); bool WriteWarning(string name, string format, params object[] args); bool WriteInformation(string name, string format, params object[] args); } The “WCFUserEventProvider” class implements this interface by making possible to send the events to the AppFabric monitoring database. The service or resource implementation can receive an “ILogger” as part of the constructor. [ServiceContract] [Export] public class OrderResource { IOrderRepository repository; ILogger logger;   [ImportingConstructor] public OrderResource(IOrderRepository repository, ILogger logger) { this.repository = repository; this.logger = logger; }   [WebGet(UriTemplate = "{id}")] public Order Get(string id, HttpResponseMessage response) { var order = this.repository.All.FirstOrDefault(o => o.OrderId == int.Parse(id, CultureInfo.InvariantCulture)); if (order == null) { response.StatusCode = HttpStatusCode.NotFound; response.Content = new StringContent("Order not found"); }   this.logger.WriteInformation("Order Requested", "Order Id {0}", id);   return order; } } The example above uses “MEF” as IoC for injecting a repository and the logger implementation into the service. You can also see how the logger is used to write an information event in the monitoring database. The following image illustrates how the custom event is injected and the information becomes available for any user in the dashboard. An issue that you might run into and I hope the WCF and AppFabric teams fixed soon is that any WCF service that uses friendly URLs with ASP.NET routing does not get listed as a available service in the WCF services tab in the AppFabric console. The complete example is available to download from here.

    Read the article

< Previous Page | 20 21 22 23 24 25 26 27  | Next Page >