Search Results

Search found 13692 results on 548 pages for 'bad practices'.

Page 102/548 | < Previous Page | 98 99 100 101 102 103 104 105 106 107 108 109  | Next Page >

  • Exception design: Custom exceptions reading data from file?

    - by User
    I have a method that reads data from a comma separated text file and constructs a list of entity objects, let's say customers. So it reads for example, Name Age Weight Then I take these data objects and pass them to a business layer that saves them to a database. Now the data in this file might be invalid, so I'm trying to figure out the best error handling design. For example, the text file might have character data in the Age field. Now my question is, should I throw an exception such as InvalidAgeException from the method reading the file data? And suppose there is length restriction on the Name field, so if the length is greater than max characters do I throw a NameTooLongException or just an InvalidNameException, or do I just accept it and wait until the business layer gets a hold of it and throw exceptions from there? (If you can point me to a good resource that would be good too)

    Read the article

  • Only perform jquery effects/operations on certain pages

    - by Galen
    Up until now i've been dropping all my jquery code right inside the document.ready function. I'm thinking that for certain situations this isnt the best way to go. for example: If i want an animation to perform when a certain page loads what is the best way to go about that. $(document).ready(function() { $("#element_1").fadeIn(); $("#element_2").delay('100').fadeIn(); $("#element_3").delay('200').fadeIn(); }); If this is right inside of document.ready then every time ANY page loads it's going to check each line and look for that element. What is the best way to tell jquery to only perform a chunk of code on a certain page to avoid this issue.

    Read the article

  • What is your strategy to avoid dynamic typing errors in Python (NoneType has not attribute x)?

    - by Koen Bok
    Python is one of my favorite languages, but I really have a love/hate relationship with it's dynamicness. Apart from the advantages, it often results in me forgetting to check a type, trying to call an attribute and getting the NoneType (or any other) has no attribute x error. A lot of them are pretty harmless but if not handled correctly they can bring down your entire app/process/etc. Over time I got better predicting where these could pop up and adding explicit type checking, but because I'm only human I miss one occasionally and then some end-user finds it. So I'm interested in your strategy to avoid these. Do you use type-checking decorators? Maybe special object wrappers? Please share...

    Read the article

  • How to handle input and parameter validation between layers?

    - by developr
    If I have a 3 layer web forms application that takes user input, I know I can validate that input using validation controls in the presentation layer. Should I also validate in the business and data layers as well to protect against SQL injection and also issues? What validations should go in each layer? Another example would be passing a ID to return a record. Should the data layer ensure that the id is valid or should that happen in BLL / UI?

    Read the article

  • C# Inheritence: Choosing what repository based on type of inherited class

    - by Oskar Kjellin
    I have been making a program that downloads information about movies from the internet. I have a base class Title, which represents all titles. Movie, Serie and Episode are inherited from that class. To save them to the database I have 2 services, MovieService and SerieService. They in turn call repositories, but that is not important here. I have a method Save(Title title) which I am not very happy with. I check for what type the title is and then call the correct service. I would like to perhaps write like this: ITitleService service = title.GetService(); title.GetSavedBy(service); So I have an abstract method on Title that returns an ITitleSaver, which will return the correct service for the instance. My question is how should I implement ITitleSaver? If I make it accept Title I will have to cast it to the correct type before calling the correct overload. Which will lead to having to deal with casting once again. What is the best approach to dealing with this? I would like to have the saving logic in the corresponding class.

    Read the article

  • Common programming mistakes for Scala developers to avoid

    - by jelovirt
    In the spirit of Common programming mistakes for Java developers to avoid? Common programming mistakes for JavaScript developers to avoid? Common programming mistakes for .NET developers to avoid? Common programming mistakes for Haskell developers to avoid? Common programming mistakes for Python developers to avoid? Common Programming Mistakes for Ruby Developers to Avoid Common programming mistakes for PHP developers to avoid? what are some common mistakes made by Scala developers, and how can we avoid them? Also, as the biggest group of new Scala developers come from Java, what specific pitfalls they have to be aware of? For example, one often cited problem Java programmers moving to Scala make is use a procedural approach when a functional one would be more suitable in Scala. What other mistakes e.g. in API design newcomers should try to avoid.

    Read the article

  • Is there a compelling reason to use quantifiers in Perl regular expressions instead of just repeatin

    - by Morinar
    I was performing a code review for a colleague and he had a regular expression that looked like this: if ($value =~ /^\d\d\d\d$/) { #do stuff } I told him he should change it to: if ($value =~ /^\d{4}$/) { #do stuff } To which he replied that he preferred the first for readability (I find the second more readable, but that's a religious debate I'll save for another day). My question: is there an actual benefit to one over the other?

    Read the article

  • Repair bad character due to encoding problem

    - by remi bourgarel
    Hi all, Recently we had an encoding problem in our system : If we had the string "æ" in our db ,it became "æ" on our web pages. Now this problem is solved, but the problem is that now we have a lot of "æ" in our database : users didn't see and validate pre-filled form with these characters. I found that If you read in utf 8 C3A6 you'll get "æ", if you read it in ascii you'll get "æ". It's strange because if I execute "select convert(varbinary(40),N'æ'),convert(varbinary(40),'æ')" I don't have the same result... Do you have any idea on how I can fix my database (ie change all "æ" to "æ") ? thx

    Read the article

  • To be effective on your home projects is it better using the same technologies used at work?

    - by systempuntoout
    To be more productive and effective, is it better to start developing an home project using the same technologies used at work? I'm not talking about a simple hello world web page but an home project with all bells and whistles that one day, maybe, you could sell on internet. This dilemma is often subject of flames between me and a friend. He thinks that if you want to make a great home-made project you need to use the same technologies used daily at work staying in the same scope too; for example, a c++ computer game programmer should develope an home-made c++ game. I'm pretty sure that developing using the same technologies used at work can be more productive at beginning, but surely less exciting and stimulating of working with other languages\ides\libraries out of your daily job. What's your opinion about that?

    Read the article

  • HELP!! Ruby & RoR Resources?

    - by aaroninfidel
    Hello, I've been a PHP Developer for a few years now and I've recently been interested in learning Ruby & Rails but I've found a lot of the resources I've found seem to be dated and not for Rails 2.0 or Ruby 1.8.6 etc... can anyone point me in the right direction? I'm running OSX 10.6 with the default ruby & rails installation. Thanks!

    Read the article

  • Controls added in the designer are null during Page_Load

    - by mwright
    All of the names below are generic and not the actual names used. I have a custom UserControl with a Panel that contains a a couple Labels, both .aspx controls. .aspx: <asp:Panel runat="server"> <asp:Label ID="label1" runat="server"> </asp:Label> </asp:Panel> <asp:Panel runat="server"> <asp:Label ID="label2" runat="server"> </asp:Label> </asp:Panel> Codebehind: private readonly Object object; protected void Page_Load(object sender, EventArgs e) { // These are the lines that are failing // label1 and label2 are null label1.Text = object.Value1; label2.Text = object.Value2; } public ObjectRow(Object objectToDisplay) { object = objectToDisplay; } On another page, in the code behind, I create a new instance of the custom user control. protected void Page_Load(object sender, EventArgs e) { CustomControl control = new CustomControl(object); } The user control takes the parameter and attempts to set the labels based off of the object passed in. The labels that it tries to assign the values to are however, null. Is this an ASP.net lifecycle issue that I'm not understanding? My understanding based on the Microsoft ASP.net lifecycle page was that page controls were available after the Page_Initialization. What is the proper way to do this? Is there a better way?

    Read the article

  • Newbie T-SQL dynamic stored procedure -- how can I improve it?

    - by Andy Jones
    I'm new to T-SQL; all my experience is in a completely different database environment (Openedge). I've learned enough to write the procedure below -- but also enough to know that I don't know enough! This routine will have to go into a live environment soon, and it works, but I'm quite certain there are a number of c**k-ups and gotchas in it that I know nothing about. The routine copies data from table A to table B, replacing the data in table B. The tables could be in any database. I plan to call this routine multiple times from another stored procedure. Permissions aren't a problem: the routine will be run by the dba as a timed job. Could I have your suggestions as to how to make it fit best-practice? To bullet-proof it? ALTER PROCEDURE [dbo].[copyTable2Table] @sdb varchar(30), @stable varchar(30), @tdb varchar(30), @ttable varchar(30), @raiseerror bit = 1, @debug bit = 0 as begin set nocount on declare @source varchar(65) declare @target varchar(65) declare @dropstmt varchar(100) declare @insstmt varchar(100) declare @ErrMsg nvarchar(4000) declare @ErrSeverity int set @source = '[' + @sdb + '].[dbo].[' + @stable + ']' set @target = '[' + @tdb + '].[dbo].[' + @ttable + ']' set @dropStmt = 'drop table ' + @target set @insStmt = 'select * into ' + @target + ' from ' + @source set @errMsg = '' set @errSeverity = 0 if @debug = 1 print('Drop:' + @dropStmt + ' Insert:' + @insStmt) -- drop the target table, copy the source table to the target begin try begin transaction exec(@dropStmt) exec(@insStmt) commit end try begin catch if @@trancount > 0 rollback select @errMsg = error_message(), @errSeverity = error_severity() end catch -- update the log table insert into HHG_system.dbo.copyaudit (copytime, copyuser, source, target, errmsg, errseverity) values( getdate(), user_name(user_id()), @source, @target, @errMsg, @errSeverity) if @debug = 1 print ( 'Message:' + @errMsg + ' Severity:' + convert(Char, @errSeverity) ) -- handle errors, return value if @errMsg <> '' begin if @raiseError = 1 raiserror(@errMsg, @errSeverity, 1) return 1 end return 0 END Thanks!

    Read the article

  • Can per-user randomized salts be replaced with iterative hashing?

    - by Chas Emerick
    In the process of building what I'd like to hope is a properly-architected authentication mechanism, I've come across a lot of materials that specify that: user passwords must be salted the salt used should be sufficiently random and generated per-user ...therefore, the salt must be stored with the user record in order to support verification of the user password I wholeheartedly agree with the first and second points, but it seems like there's an easy workaround for the latter. Instead of doing the equivalent of (pseudocode here): salt = random(); hashedPassword = hash(salt . password); storeUserRecord(username, hashedPassword, salt); Why not use the hash of the username as the salt? This yields a domain of salts that is well-distributed, (roughly) random, and each individual salt is as complex as your salt function provides for. Even better, you don't have to store the salt in the database -- just regenerate it at authentication-time. More pseudocode: salt = hash(username); hashedPassword = hash(salt . password); storeUserRecord(username, hashedPassword); (Of course, hash in the examples above should be something reasonable, like SHA-512, or some other strong hash.) This seems reasonable to me given what (little) I know of crypto, but the fact that it's a simplification over widely-recommended practice makes me wonder whether there's some obvious reason I've gone astray that I'm not aware of.

    Read the article

  • Java 'Prototype' pattern - new vs clone vs class.newInstance

    - by Guillaume
    In my project there are some 'Prototype' factories that create instances by cloning a final private instance. The author of those factories says that this pattern provides better performance than calling 'new' operator. Using google to get some clues about that, I've found nothing really relevant about that. Here is a small excerpt found in a javdoc from an unknown project javdoc from an unknown project Sadly, clone() is rather slower than calling new. However it is a lot faster than calling java.lang.Class.newInstance(), and somewhat faster than rolling our own "cloner" method. For me it's looking like an old best practice of the java 1.1 time. Does someone know more about this ? Is this a good practice to use that with 'modern' jvm ?

    Read the article

  • advice on working on remote asp.net applications

    - by Jonesy
    Hi folks, I'm a (relatively new) developer using asp.net with VB.NET. Currently all my applications are developed on my PC and then are built and moved onto the web server. I'm going to be working remotely for 3 months in which time I'll be connecting to the company network via VPN. What is the best way to access my projects? I need to have the projects stored on the company network so that others can access them too. So simply copying the projects to my laptop, working on them, then copying them back won't suffice. I tried to just open the projects off of the network share but am getting application trust problems. I'm just wondering what other developers do in this situation? Jonesy

    Read the article

  • VB Classes Best Practice - give all properties values?

    - by Becky Franklin
    Sorry if this is a bit random, but is it good practice to give all fields of a class a value when the class is instanciated? I'm just wondering if its better practice to have a constuctor that takes no parameters and gives all the fields default values, or whether fields that have values should be assigned and others left alone until required? I hope that makes sense, Becky

    Read the article

  • Java operator overloading

    - by nimcap
    Not using operators makes my code obscure. (aNumber / aNother) * count is better than aNumber.divideBy(aNother).times(count) After 6 months of not writing a single comment I had to write a comment to the simple operation above. Usually I refactor until I don't need comment. And this made me realize that it is easier to read and perceive math symbols and numbers than their written forms. For example TWENTY_THOUSAND_THIRTEEN.plus(FORTY_TWO.times(TWO_HUNDERED_SIXTY_ONE)) is more obscure than 20013 + 42*261 So do you know a way to get rid of obscurity while not using operator overloading in Java? Update: I did not think my exaggeration on comments would cause such trouble to me. I am admitting that I needed to write comment a couple of times in 6 months. But not more than 10 lines in total. Sorry for that. Update 2: Another example: budget.plus(bonusCoefficient.times(points)) is more obscure than budget + bonusCoefficient * points I have to stop and think on the first one, at first sight it looks like clutter of words, on the other hand, I get the meaning at first look for the second one, it is very clear and neat. I know this cannot be achieved in Java but I wanted to hear some ideas about my alternatives.

    Read the article

< Previous Page | 98 99 100 101 102 103 104 105 106 107 108 109  | Next Page >