Search Results

Search found 6690 results on 268 pages for 'worst practices'.

Page 72/268 | < Previous Page | 68 69 70 71 72 73 74 75 76 77 78 79  | Next Page >

  • COM: How to handle a specific exception?

    - by Ian Boyd
    i'm talking to a COM object (Microsoft ADO Recordset object). In a certain case the recordset will return a failed (i.e. negative) HRESULT, with the message: Item cannot be found in the collection corresponding to the requested name or ordinal i know what this error message means, know why it happened, and i how to fix it. But i know these things because i read the message, which fortunately was in a language i understand. Now i would like to handle this exception specially. The COM object threw an HRESULT of 0x800A0CC1 In an ideal world Microsoft would have documented what errors can be returned when i try to access: records.Fields.Items( index ) with an invalid index. But they do not; they most they say is that an error can occur, i.e.: If Item cannot find an object in the collection corresponding to the Index argument, an error occurs. Given that the returned error code is not documented, is it correct to handle a specific return code of `0x800A0CC1' when i'm trying to trap the exception: Item cannot be found in the collection corresponding to the requested name or ordinal ? Since Microsoft didn't document the error code, they technically change it in the future.

    Read the article

  • CSS selectors : should I make my CSS easier to read or optimise the speed

    - by Laurent Bourgault-Roy
    As I was working on a small website, I decided to use the PageSpeed extension to check if their was some improvement I could do to make the site load faster. However I was quite surprise when it told me that my use of CSS selector was "inefficient". I was always told that you should keep the usage of the class attribute in the HTML to a minimum, but if I understand correctly what PageSpeed tell me, it's much more efficient for the browser to match directly against a class name. It make sense to me, but it also mean that I need to put more CSS classes in my HTML. It make my .css file harder to read. I usually tend to mark my CSS like this : #mainContent p.productDescription em.priceTag { ... } Which make it easy to read : I know this will affect the main content and that it affect something in a paragraph tag (so I wont start to put all sort of layout code in it) that describe a product and its something that need emphasis. However it seem I should rewrite it as .priceTag { ... } Which remove all context information about the style. And if I want to use differently formatted price tag (for example, one in a list on the sidebar and one in a paragraph), I need to use something like that .paragraphPriceTag { ... } .listPriceTag { ... } Which really annoy me since I seem to duplicate the semantic of the HTML in my classes. And that mean I can't put common style in an unqualified .priceTag { ... } and thus I need to replicate the style in both CSS rule, making it harder to make change. (Altough for that I could use multiple class selector, but IE6 dont support them) I believe making code harder to read for the sake of speed has never been really considered a very good practice . Except where it is critical, of course. This is why people use PHP/Ruby/C# etc. instead of C/assembly to code their site. It's easier to write and debug. So I was wondering if I should stick with few CSS classes and complex selector or if I should go the optimisation route and remove my fancy CSS selectors for the sake of speed? Does PageSpeed make over the top recommandation? On most modern computer, will it even make a difference?

    Read the article

  • Whats the point of STL?

    - by Jonathan D
    I've been programming c++ for about a year now and when i'm looking about i see lots of references to STL. Can some one please tell me what it does? and the advantages and disadvantageous of it? thanks

    Read the article

  • Database design for credit based purchases

    - by FreshCode
    I need an elegant way to implement credit-based purchases for an online store with a small variety of products which can be purchased using virtual credit or real currency. Alternatively, products could only be priced in credits. Previous work I have implemented credit-based purchasing before using different product types (eg. Credit, Voucher or Music) with post-order processing to assign purchased credit to users in the form of real currency, which could subsequently be used to discount future orders' charge totals. This worked fairly well as a makeshift solution, but did not succeed in disconnecting the virtual currency from the real currency, which is what I'd like to do, since spending credits is psychologically easier for customers than spending real currency. Design I need guidance on designing the database correctly with support for the simultaneous bulk purchase of credits at a discount along with real currency products. Alternatively, should all products be priced in credits and only credit have a real currency value? Existing Database Design Partial Products table: ProductId Title Type UnitPrice SalePrice Partial Orders table: OrderId UserId (related to Users table, not shown) Status Value Total Partial OrderItems table (similar to CartItems table): OrderItemId OrderId (related to Orders table) ProductId (related to Products table) Quantity UnitPrice SalePrice Prospective UserCredits table: CreditId UserId (related to Users table, not shown) Value (+/- value. Summed over time to determine saldo.) Date I'm using ASP.NET MVC and LINQ-to-SQL on a SQL Server database.

    Read the article

  • Unit Testing in ASP.NET MVC: Minimising the number of asserts per test

    - by Neil Barnwell
    I'm trying out TDD on a greenfield hobby app in ASP.NET MVC, and have started to get test methods such as the following: [Test] public void Index_GetRequest_ShouldReturnPopulatedIndexViewModel() { var controller = new EmployeeController(); controller.EmployeeService = GetPrePopulatedEmployeeService(); var actionResult = (ViewResult)controller.Index(); var employeeIndexViewModel = (EmployeeIndexViewModel)actionResult.ViewData.Model; EmployeeDetailsViewModel employeeViewModel = employeeIndexViewModel.Items[0]; Assert.AreEqual(1, employeeViewModel.ID); Assert.AreEqual("Neil Barnwell", employeeViewModel.Name); Assert.AreEqual("ABC123", employeeViewModel.PayrollNumber); } Now I'm aware that ideally tests will only have one Assert.xxx() call, but does that mean I should refactor the above to separate tests with names such as: Index_GetRequest_ShouldReturnPopulatedIndexViewModelWithCorrectID Index_GetRequest_ShouldReturnPopulatedIndexViewModelWithCorrectName Index_GetRequest_ShouldReturnPopulatedIndexViewModelWithCorrectPayrollNumber ...where the majority of the test is duplicated code (which therefore is being tested more than once and violates the "keep tests fast" advice)? That seems to be taking it to the extreme to me, so if I'm right as I am, what is the real-world meaning of the "one assert per test" advice?

    Read the article

  • Best practice? iphone: sync data

    - by Andy Jacobs
    So i'm working on a project where there is data visualization. My ultimate goal is that i have a set of data shipped with the download of the iphone app. But i want it connected to a backend, that if the iphone has a connection with the internet. it can sync the changes from the backend. The syncing is no problem or the connection between the backend & the iphone. But what should i use as data storage on my iphone? what is the best way. my data is purely text and doesn't have to be secure. But it's main feature should be updating certain parts of data ( adding and deleting are not so important ) so what is the easiest (read: least time consuming development ) or the best way? sqlite? plist? ..?

    Read the article

  • Difference between URI and URL

    - by Sarfraz
    If you read the documentation of CodeIgniter or Kohana, there is a lot of confusion about the usage of URI and URL. Sometimes they use one and other times the other. They also incorporate URI class which makes it easier working with URLs. I know that: URI stands for Uniform Resource Identifier URL stands for Uniform Resource Locator But that doesn't make much sense. What exactly is the difference? or are they same?

    Read the article

  • What is the best practice for using lock within inherited classes

    - by JDMX
    I want to know if one class is inheriting from another, is it better to have the classes share a lock object that is defined at the base class or to have a lock object defined at each inheritance level. A very simple example of a lock object on each level of the class public class Foo { private object thisLock = new object(); private int ivalue; public int Value { get { lock( thisLock ) { return ivalue; } } set { lock( thisLock ) { ivalue= value; } } } } public class Foo2: Foo { private object thisLock2 = new object(); public int DoubleValue { get { lock( thisLock2 ) { return base.Value * 2; } } set { lock( thisLock2 ) { base.Value = value / 2; } } } } public class Foo6: Foo2 { private object thisLock6 = new object(); public int TripleDoubleValue { get { lock( thisLock6 ) { return base.DoubleValue * 3; } } set { lock( thisLock6 ) { base.DoubleValue = value / 3; } } } } A very simple example of a shared lock object public class Foo { protected object thisLock = new object(); private int ivalue; public int Value { get { lock( thisLock ) { return ivalue; } } set { lock( thisLock ) { ivalue= value; } } } } public class Foo2: Foo { public int DoubleValue { get { lock( thisLock ) { return base.Value * 2; } } set { lock( thisLock ) { base.Value = value / 2; } } } } public class Foo6: Foo2 { public int TripleDoubleValue { get { lock( thisLock ) { return base.DoubleValue * 3; } } set { lock( thisLock ) { base.DoubleValue = value / 3; } } } } Which example is the preferred way to manage locking within an inherited class?

    Read the article

  • Is there added overhead to looking up a column in a DataTable by name rather than by index?

    - by Ben McCormack
    In a DataTable object, is there added overhead to looking up a column value by name thisRow("ColumnA") rather than by the column index thisRow(0)? In which scenarios might this be an issue. I work on a team that has lots of experience writing VB6 code and I noticed that didn't do column lookups by name for DataTable objects or data grids. Even in .NET code, we use a set of integer constants to reference column names in these types of objects. I asked our team lead why this was so, and he mentioned that in VB6, there was a lot of overhead in looking up data by column name rather than by index. Is this still true for .NET? Example code (in VB.NET, but same applies to C#): Public Sub TestADOData() Dim dt As New DataTable 'Set up the columns in the DataTable ' dt.Columns.Add(New DataColumn("ID", GetType(Integer))) dt.Columns.Add(New DataColumn("Name", GetType(String))) dt.Columns.Add(New DataColumn("Description", GetType(String))) 'Add some data to the data table ' dt.Rows.Add(1, "Fred", "Pitcher") dt.Rows.Add(3, "Hank", "Center Field") 'Method 1: By Column Name ' For Each r As DataRow In dt.Rows Console.WriteLine( _ "{0,-2} {1,-10} {2,-30}", r("ID"), r("Name"), r("Description")) Next Console.WriteLine() 'Method 2: By Column Name ' For Each r As DataRow In dt.Rows Console.WriteLine("{0,-2} {1,-10} {2,-30}", r(0), r(1), r(2)) Next End Sub Is there an case where method 2 provides a performance advantage over method 1?

    Read the article

  • Is it good or bad practice to use var everywhere? [closed]

    - by Earlz
    Possible Duplicate: Use of var keyword in C# Hello, I've recently been discovering the awesomeness that is the var keyword in C#. Well, I didn't think about it before but I just wrote lines of code that are along the lines of var con=CreateNewConnection(); Where this would usually be IdbConnection con=CreateNewConnection(); Is this a good use of var? Is it possible to use var too often? Are there any downsides to using it? Also, one more point of consideration: We are not worried about backwards compatability. We just care that it runs on .NET 3.5

    Read the article

  • iPhone development: Best method to allow user to chose search scope

    - by Mark Pemburn
    Hi, I'm developing my first iPhone app and want to allow the user to select the scope of their search in a more complex way than the 'scope buttons' permit. The app is related to wines and I want to the user to be able to select the 'color' (Red, White, Blush, etc.) first, and then select the type/varietal within that category. Right now, I'm using the UISearchBar's scope buttons for the colors and tapping the button opens a view with the selection of colors. This is okay except that once the 'Red' button has been selected, I can't select it a second time to change my choice of type (e.g., change from 'Merlot' to 'Syrrah', etc.) If there's a better way to do this, I'm willing to scrap my method and start from scratch. Thanks!

    Read the article

  • In Ruby, how to implement global behaviour?

    - by Gordon McAllister
    Hi all, I want to implement the concept of a Workspace. This is a global concept - all other code will interact with one instance of this Workspace. The Workspace will be responsible for maintaining the current system state (i.e. interacting with the system model, persisting the system state etc) So what's the best design strategy for my Workspace, bearing in mind this will have to be testable (using RSpec now, but happy to look at alternatives). Having read thru some open source projects out there and I've seen 3 strategies. None of which I can identify as "the best practice". They are: Include the singleton class. But how testable is this? Will the global state of Workspace change between tests? Implemented all behaviour as class methods. Again how do you test this? Implemented all behaviour as module methods. Not sure about this one at all! Which is best? Or is there another way? Thanks, Gordon

    Read the article

  • Normalize or Denormalize in high traffic websites

    - by Inam Jameel
    what is the best practice for database design for high traffic websites like this one stackoverflow? should one must use normalize database for record keeping or normalized technique or combination of both? is it sensible to design normalize database as main database for record keeping to reduce redundancy and at the same time maintain another denormalized form of database for fast searching? or main database should be denormalize and one can make normalized views in the application level for fast database operations? or beside above mentioned approach? what is the best practice of designing high traffic websites???

    Read the article

  • Convert methods from Java-actionscript to ObjectiveC

    - by eco_bach
    Hi I'm tring to convert the following 3 methods from java-actionscript to Objective C. Part of my confusion I think is not knowing what Number types, primitives I should be using. ie in actionscript you have only Number, int, and uint. These are the 3 functions I am trying to convert public function normalize(value:Number, minimum:Number, maximum:Number):Number { return (value - minimum) / (maximum - minimum); } public function interpolate(normValue:Number, minimum:Number, maximum:Number):Number { return minimum + (maximum - minimum) * normValue; } public function map(value:Number, min1:Number, max1:Number, min2:Number, max2:Number):Number { return interpolate( normalize(value, min1, max1), min2, max2); } This is what I have so far -(float) normalize:(float*)value withMinimumValue:(float*)minimum withMaximumValue:(float*)maximum { return (value - minimum) / (maximum - minimum); } -(float) interpolate:(float*)normValue withMinimumValue:(float*)minimum withMaximumValue:(float*)maximum { return minimum + (maximum - minimum) * normValue; } -(float) map:(float*)value withMinimumValue1:(float*)min1 withMaximumValue1:(float*)max1 withMinimumValue2:(float*)min2 withMaximumValue2:(float*)max2 { return interpolate( normalize(value, min1, max1), min2, max2); }

    Read the article

  • Best practice No1: inline search layout across browsers

    - by Sixfoot Studio
    Ok, I have managed to fix my version of this example using a multitude of hacks and I would like to see how others would tackle this problem making this cross-browser compatible without too many hacks. <div class="searchDiv"> <img src="Images/left.gif" class="left" height="19" width="3" /> <input id="TextBox" type="text" class="searchField" /> <img src="Images/right.gif" height="19"width="3" class="right" /> <a href="" class="submit">Submit</a> <img src="Images/box-arrow.gif" class="linkArrow" width="8" height="14" /> </div> I am using a Transitional DTD in my example. Based on the everyone else's CSS examples, comments and answers I will make the final vote. I'd love to see more of these scenarios come up so that people have a library of "best practice" methods which they can find on SO. Good luck

    Read the article

  • Should I map a domain object to a view model using an optional constructor?

    - by Byron Sommardahl
    I'd like to be able to map a domain model to a view model by newing up a view model and passing in the contributing domain model as a parameter (like the code below). My motivation is to keep from re-using mapping code AND to provide a simple way to map (not using automapper yet). A friend says the view model should not know anything about the "payment" domain model that's being passed into the optional constructor. What do you think? public class LineItemsViewModel { public LineItemsViewModel() { } public LineItemsViewModel(IPayment payment) { LineItemColumnHeaders = payment.MerchantContext.Profile.UiPreferences.LineItemColumnHeaders; LineItems = LineItemDomainToViewModelMapper.MapToViewModel(payment.LineItems); ConvenienceFeeAmount = payment.ConvenienceFee.Fee; SubTotal = payment.PaymentAmount; Total = payment.PaymentAmount + payment.ConvenienceFee.Fee; } public IEnumerable<Dictionary<int, string>> LineItems { get; set; } public Dictionary<int, string> LineItemColumnHeaders { get; set; } public decimal SubTotal { get; set; } public decimal ConvenienceFeeAmount { get; set; } public decimal Total { get; set; } }

    Read the article

  • Split html text in a SEO friendly manner

    - by al nik
    I've some html text like <h1>GreenWhiteRed</h1> Is it SEO friendly to split this text in something like <h1><span class="green">Green</span><span class="white">White</span><span class="red">Red</span></h1> Is the text still ranking well and is it interpreted as a single word 'GreenWhiteRed'?

    Read the article

  • Is it bad practice to apply class-based design to JavaScript programs?

    - by helixed
    JavaScript is a prototyped-based language, and yet it has the ability to mimic some of the features of class-based object-oriented languages. For example, JavaScript does not have a concept of public and private members, but through the magic of closures, it's still possible to provide the same functionality. Similarly, method overloading, interfaces, namespaces and abstract classes can all be added in one way or another. Lately, as I've been programming in JavaScript, I've felt like I'm trying to turn it into a class-based language instead of using it in the way it's meant to be used. It seems like I'm trying to force the language to conform to what I'm used to. The following is some JavaScript code I've written recently. It's purpose is to abstract away some of the effort involved in drawing to the HTML5 canvas element. /* Defines the Drawing namespace. */ var Drawing = {}; /* Abstract base which represents an element to be drawn on the screen. @param The graphical context in which this Node is drawn. @param position The position of the center of this Node. */ Drawing.Node = function(context, position) { return { /* The method which performs the actual drawing code for this Node. This method must be overridden in any subclasses of Node. */ draw: function() { throw Exception.MethodNotOverridden; }, /* Returns the graphical context for this Node. @return The graphical context for this Node. */ getContext: function() { return context; }, /* Returns the position of this Node. @return The position of this Node. */ getPosition: function() { return position; }, /* Sets the position of this Node. @param thePosition The position of this Node. */ setPosition: function(thePosition) { position = thePosition; } }; } /* Define the shape namespace. */ var Shape = {}; /* A circle shape implementation of Drawing.Node. @param context The graphical context in which this Circle is drawn. @param position The center of this Circle. @param radius The radius of this circle. @praram color The color of this circle. */ Shape.Circle = function(context, position, radius, color) { //check the parameters if (radius < 0) throw Exception.InvalidArgument; var node = Drawing.Node(context, position); //overload the node drawing method node.draw = function() { var context = this.getContext(); var position = this.getPosition(); context.fillStyle = color; context.beginPath(); context.arc(position.x, position.y, radius, 0, Math.PI*2, true); context.closePath(); context.fill(); } /* Returns the radius of this Circle. @return The radius of this Circle. */ node.getRadius = function() { return radius; }; /* Sets the radius of this Circle. @param theRadius The new radius of this circle. */ node.setRadius = function(theRadius) { radius = theRadius; }; /* Returns the color of this Circle. @return The color of this Circle. */ node.getColor = function() { return color; }; /* Sets the color of this Circle. @param theColor The new color of this Circle. */ node.setColor = function(theColor) { color = theColor; }; //return the node return node; }; The code works exactly like it should for a user of Shape.Circle, but it feels like it's held together with Duct Tape. Can somebody provide some insight on this?

    Read the article

  • When should I be cautious using about data binding in .NET?

    - by Ben McCormack
    I just started working on a small team of .NET programmers about a month ago and recently got in a discussion with our team lead regarding why we don't use databinding at all in our code. Every time we work with a data grid, we iterate through a data table and populate the grid row by row; the code usually looks something like this: Dim dt as DataTable = FuncLib.GetData("spGetTheData ...") Dim i As Integer For i = 0 To dt.Rows.Length - 1 '(not sure why we do not use a for each here)' gridRow = grid.Rows.Add() gridRow(constantProductID).Value = dt("ProductID").Value gridRow(constantProductDesc).Value = dt("ProductDescription").Value Next '(I am probably missing something in the code, but that is basically it)' Our team lead was saying that he got burned using data binding when working with Sheridan Grid controls, VB6, and ADO recordsets back in the nineties. He's not sure what the exact problem was, but he remembers that binding didn't work as expected and caused him some major problems. Since then, they haven't trusted data binding and load the data for all their controls by hand. The reason the conversation even came up was because I found data binding to be very simple and really liked separating the data presentation (in this case, the data grid) from the in-memory data source (in this case, the data table). "Loading" the data row by row into the grid seemed to break this distinction. I also observed that with the advent of XAML in WPF and Silverlight, data-binding seems like a must-have in order to be able to cleanly wire up a designer's XAML code with your data. When should I be cautious of using data-binding in .NET?

    Read the article

  • effective retrieve for a voting system in PHP

    - by Adnan
    Hello, I have a system where registered users can vote up/vote down comment for a picture. Something very similar to SO's voting system. I store the votes in a table with values as such; vote_id | vote_comment_id | vote_user_id | vote_date Now I have few a question concerned the speed and efficiency for the following; PROB: Once a user opens the picture page with comments I need, if that user has already voted UP/DOWN a comment to show it like; "you voted up" or "you voted down" next to the comment (in SO it the vote image is highlighted) MY POSSIBLE SOL: Right now when I open a picture page for each comment I loop thru, I loop thru my table of votes as well and check if a user has voted and show the status (I compare the vote_user_id with the user's session). How efficient is this? Anyone have a better approach to tackle this kind of problem?

    Read the article

  • What is the best way to post data from web browser to server?

    - by Kronass
    Hi, I want to know what is the best way to send data from web browser to server using post method. I've seen a practice where they wrap all the elements data in XML, convert it into Base64 string and then post it to the server (via Ajax or hidden field). this way will not work if the Javascript is disabled, any how if I ignored this. is it a good practice to wrap elements into XML (or create my custom wrapper in general) and post them to server saying it will enhance the maintainability of the code or just stick with the classical way and no need to add unnecessary text in the post.

    Read the article

< Previous Page | 68 69 70 71 72 73 74 75 76 77 78 79  | Next Page >