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• Building a custom (dynamic) dataset and grid

  - by marko.ivanovski.nz

  Hi, I'm in the process of building a dynamic table in which you can add/remove rows & columns so it varies in size depending on what the user wants. Its purpose is to store properties for a product, but there can be from 1 to 10 different properties(columns) per product, and multiple instances(rows) of the product as well. Here's a screenshot of what I mean http://i40.tinypic.com/nbqkxc.jpg As you can see I need the structure to be completely up to the client which is where I'm getting stuck. I've started writing a custom DataSet that has "add column" & "add row" buttons, and have built a custom Table with Textboxes in each cell which builds from that dataset. I have no idea how to store the data on submit though, and to make it even more complex I need to store this in the database as a string which I think I can do by converting it to XML. Any help is appreciated, I think I just need a pointer in the right direction and am happy to do research from there. Thanks in advance. Marko

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• How do I simulate the usage of a sequence of web pages?

  - by Rory Becker

  I have a simple sequence of web pages written in ASP.Net 3.5 SP1. Page1 - A Logon Form.... txtUsername, txtPassword and cmdLogon Page2 - A Menu (created using DevExpress ASP.Net controls) Page3 - The page redirected to by the server in the event that the user picks the right menu option in Page2 I would like to create a threaded program to simulate many users trying to use this sequence of pages. I have managed to create a host Winforms app which Launches a new thread for each "User" I have further managed to work out the basics of WebRequest enough to perform a request which retrieves the Logon page itself. Dim Request As HttpWebRequest = TryCast(WebRequest.Create("http://MyURL/Logon.aspx"), HttpWebRequest) Dim Response As HttpWebResponse = TryCast(Request.GetResponse(), HttpWebResponse) Dim ResponseStream As StreamReader = New StreamReader(Response.GetResponseStream(), Encoding.GetEncoding(1252)) Dim HTMLResponse As String = ResponseStream.ReadToEnd() Response.Close() ResponseStream.Close() Next I need to simulate the user having entered information into the 2 TextBoxes and pressing logon.... I have a hunch this requires me to add the right sort of "PostData" to the request. before submitting. However I'm also concerned that "ViewState" may be an issue. Am I correct regarding the PostData? How do I add the postData to the request? Do I need to be concerned about Viewstate? Update: While I appreciate that Selenium or similar products are useful for acceptance testing , I find that they are rather clumsy for what amounts to load testing. I would prefer not to load 100 instances of Firefox or IE in order to simulate 100 users hitting my site. This was the reason I was hoping to take the ASPNet HttpWebRequest route.

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• How to deploy SQL Reporting 2005 when Data Sources are locked?

  - by spoulson

  The DBAs here maintain all SQL Server and SQL Reporting servers. I have a custom developed SQL Reporting 2005 project in Visual Studio that runs fine on my local SQL Database and Reporting instances. I need to deploy to a production server, so I had a folder created on a SQL Reporting 2005 server with permissions to upload files. Normally, a deploy from within Visual Studio is all that is needed to upload the report files. However, for security purposes, data sources are maintained explicitly by DBAs and stored in a separated locked down common folder on the reporting server. I had them create the data source for me. When I attempt to deploy from VS, it gives me the error "The item '/Data Sources' already exists." I get this whether I'm deploying the whole project or just a single report file. I already set OverwriteDataSources=false in the project properties. The TargetServer URL and folder are verified correct. I suppose I could copy the files manually, but I'd like to be able to deploy from within VS. What could I be doing wrong?

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• 2 Mutually exclusive RadioButton "Lists"

  - by user72603

  I think this has to be THE most frustrating thing I've ever done in web forms. Yet one would think it would be the easiest of all things in the world to do. That is this: I need 2 separate lists of radiobuttons on my .aspx page. One set allows a customer to select an option. The other set does also but for a different purpose. But only one set can have a selected radiobutton. Ok I've tried this using 2 asp.net Radiobuttonlists controls on the same page. Got around the nasty bug with GroupName (asp.net assigns the control's uniqueID which prevents the groupname from ever working because now, 2 radiobuttonlists can't have the same groupname for all their radiobuttons because each radiobuttonlist has a different uniqueID thus the bug assigns the unique ID as the name attribute when the buttons are rendered. since the name sets are different, they are not mutually exclusive). Anyway, so I created that custom RadioButtonListcontrol and fixed that groupname problem. But when ended up happening is when I went to put 2 instances of my new custom radiobuttonlist control on my .aspx page, all was swell until I noticed that every time I checked for radiobuttonlist1.SelectedValue or radiobuttonlist2.SelectedValue (did not matter which I was checking) the value always spit back string.empty and i was not able to figure out why (see http://forums.asp.net/t/1401117.aspx). Ok onto the third try tonight and into the break of dawn (no sleep). I tried to instead just scrap trying to use 2 custom radiobuttonlists altogether because of that string.empty issue and try to spit out 2 sets of radiobuttonlists via using 2 asp.net repeaters and a standard input HTML tag inside. Got that working. Ok but the 2 lists still are not mutually exclusive. I can select a value in the first set of radiobuttons from repeater1 and same goes for repeater2. I cannot for the life of me get the "sets" to be mutually exclusive sets of radiobuttons.

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• Automatic .NET code, nhibernate session, and LINQ datacontext clean-up?

  - by AverageJoe719

  Hi all, in my goal to adopt better coding practices I have a few questions in general about automatic handling of code. I have heard different answers both from online and talking with other developers/programmers at my work. I am not sure if I should have split them into 3 questions, but they all seem sort of related: 1) How does .NET handle instances of classes and other code things that take up memory? I recently found out about using the factory pattern for certain things like service classes so that they are only instantiated once in the entire application, but then I was told that '.NET handles a lot of that stuff automatically when mentioning it.' 2) How does Nhibernate's session handle automatic clean-up of un-used things? I've seen some say that it is great at handling things automatically and you should just use a session factory and that's it, no need to close it. But I have also read and seem many examples where people close the hibernate session. 3) How does LINQ's datacontext handle this? Most of the time I never .disposed my datacontext's and the app didn't see to take a performance hit (though I am not running anything super intensively), but it seems like most people recommend disposing of your datacontext after you are done with it. However, I have seen many many code examples where the dispose method is never called. Also in general I found it kind of annoying that you couldn't access even one-deep child related objects after disposing of the datacontext unless you explicity also grabbed them in the query. Thanks all. I am loving this site so far, I kind of get lost and spend hours just reading things on here. =)

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• Improving field get and set performance with ASM or Javassist

  - by ng

  I would like to avoid reflection in an open source project I am developing. Here I have classes like the following. public class PurchaseOrder { @Property private Customer customer; @Property private String name; } I scan for the @Property annotation to determine what I can set and get from the PurchaseOrder reflectively. There are many such classes all using java.lang.reflect.Field.get() and java.lang.reflect.Field.set(). Ideally I would like to generate for each property an invoker like the following. public interface PropertyAccessor<S, V> { public void set(S source, V value); public V get(S source); } Now when I scan the class I can create a static inner class of PurchaseOrder like so. static class customer_Field implements PropertyAccessor<PurchaseOrder, Customer> { public void set(PurchaseOrder order, Customer customer) { order.customer = customer; } public Customer get(PurchaseOrder order) { return order.customer; } } With these I totally avoid the cost of reflection. I can now set and get from my instances with native performance. Can anyone tell me how I would do this. A code example would be great. I have searched the net for a good example but can find nothing like this. The ASM and Javasist examples are pretty poor also. The key here is that I have an interface that I can pass around. So I can have various implementations, perhaps one with Java Reflection as a default, one with ASM, and one with Javassist? Any help would be greatly appreciated.

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• Checking data of all same class elements

  - by Tiffani

  I need the code to check the data-name value of all instances of .account-select. Right now it just checks the first .account-select element and not any subsequent ones. The function right now is on click of an element such as John Smith, it checks the data-name of the .account-select lis. If the data-names are the same, it does not create a new li with the John Smith data. If no data-names are equal to John Smith, then it adds an li with John Smith. This is the JS-Fiddle I made for it so you can see what I am referring to: http://jsfiddle.net/rsxavior/vDCNy/22/ Any help would be greatly appreciated. This is the Jquery Code I am using right now. $('.account').click(function () { var acc = $(this).data("name"); var sel = $('.account-select').data("name"); if (acc === sel) { } else { $('.account-hidden-li').append('<li class="account-select" data-name="'+ $(this).data("name") +'">' + $(this).data("name") + '<a class="close bcn-close" data-dismiss="alert" href="#">&times;</a></li>'); } }); And the HTML: <ul> <li><a class="account" data-name="All" href="#">All</a></li> <li><a class="account" data-name="John Smith" href="#">John Smith</a></li> </ul> <ul class="account-hidden-li"> <ul>

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• write html content from javascript

  - by Nikita Rybak

  There's one thing I want to do with javascript, but don't know how. In a perfect world it would look like this: <p>My very cool page!</p> <script type="text/javascript"> document.write('<div>some content</div>'); </script> And this script would insert <div>some content</div> right before (or after, or instead of) script tag. But in the real world, document.write starts writing html anew, removing any static content in the page (<p> tag, in this case). This is simplified example, but should give you the idea. I know that I can statically put <div id="some_id"></div> before script tag and insert html in it from js, but I wanna be able to use multiple instances of this snippet without changing it (generating random id manually) each time. I'm ok to use jquery or any other existing library as well. Is there any way to achieve this? Thanks!

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• MySQL Query That Can Pull the Data I am Seeking?

  - by Amy

  On the project I am working on, I am stuck with the table structure from Hades. Two things to keep in mind: I can't change the table structure right now. I'm stuck with it for the time being. The queries are dynamically generated and not hard coded. So, while I am asking for a query that can pull this data, what I am really working toward is an algorithm that will generate the query I need. Hopefully, I can explain the problem without making your eyes glaze over and your brain implode. We have an instance table that looks (simplified) along these lines: Instances InstanceID active 1 Y 2 Y 3 Y 4 N 5 Y 6 Y Then, there are multiple data tables along these lines: Table1 InstanceID field1 reference_field2 1 John 5 2 Sally NULL 3 Fred 6 4 Joe NULL Table2 InstanceID field3 5 1 6 1 Table3 InstanceID fieldID field4 5 1 Howard 5 2 James 6 2 Betty Please note that reference_field2 in Table1 contains a reference to another instance. Field3 in Table2 is a bit more complicated. It contains a fieldID for Table 3. What I need is a query that will get me a list as follows: InstanceID field1 field4 1 John Howard 2 Sally 3 Fred The problem is, in the query I currently have, I do not get Fred because there is no entry in Table3 for fieldID 1 and InstanceID 6. So, the very best list I have been able to get thus far is InstanceID field1 field4 1 John Howard 2 Sally In essence, if there is an entry in Table1 for Field 2, and there is not an entry in Table 3 that has the instanceID contained in field2 and the field ID contained in field3, I don't get the data from field1. I have looked at joins till I'm blue in the face, and I can't see a way to handle the case when table3 has no entry.

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• Accessing the stringValue from NSTextFields on different NIBs

  - by Kyle Zaragoza

  I'm having an extremely difficult time trying to access information from an object (e.g. an NSTextField) that is located on a NIB other than my "MainMenu.nib". My current setup: I have a MainMenu.xib that contains only a toolbar at the top and an NSView. I have four other .xib files containing custom NSViews and each of their File Owner's are assigned to a NSViewController subclass which I have created for each. My MainMenu.xib contains an object that is set to my WindowController subclass that takes care of swapping the fours views into the NSView on my MainMenu.xib. All of this works fantastic. Where I have a problem: I have another class that acts as the brains to my application which sends and receives data from an online server, all of the methods I have created rely on inputs from the user that are located on the individual .xibs that swap into my MainMenu.xib's NSview. Unfortunately I have no idea on how to grab the information from the NSTextFields, textViews, etc. that are located on my individual .xib files. What I've tried: I have tried setting the File Owner's of the four individual .xibs to my "brains" class and connecting outlets defined in my "brains".h, but when I call [textField stringValue] I receive a NULL response. I'm thinking this is because I'm creating multiple instances of my "brains" class but not totally sure. Any help on accessing information from textFields from other nibs would be a great benefit, thanks in advance.

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• Is the RESTORE process dependent on schema?

  - by Martin Aatmaa

  Let's say I have two database instances: InstanceA - Production server InstanceB - Test server My workflow is to deploy new schema changes to InstanceB first, test them, and then deploy them to InstanceA. So, at any one time, the instance schema relationship looks like this: InstanceA - Schema Version 1.5 InstanceB - Schema Version 1.6 (new version being tested) An additional part of my workflow is to keep the data in InstanceB as fresh as possible. To fulfill this, I am taking the database backups of InstanceA and applying them (restoring them) to InstanceB. My question is, how does schema version affect the restoral process? I know I can do this: Backup InstanceA - Schema Version 1.5 Restore to InstanceB - Schema Version 1.5 But can I do this? Backup InstanceA - Schema Version 1.5 Restore to InstanceB - Schema Version 1.6 (new version being tested) If no, what would the failure look like? If yes, would the type of schema change matter? For example, if Schema Version 1.6 differed from Schema Version 1.5 by just having an altered storec proc, I imagine that this type of schema change should't affect the restoral process. On the other hand, if Schema Version 1.6 differed from Schema Version 1.5 by having a different table definition (say, an additional column), I image this would affect the restoral process. I hope I've made this clear enough. Thanks in advance for any input!

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• Struggling to create correct relationships in MS Access

  - by Yandawl

  http://img714.imageshack.us/img714/7820/croppercapture1.png Basically: an award(course) has many units, which can be either optional or core(mandatory), depending on the award. So for example: the unit 'Advanced Software Engineering' maybe a core unit for the award 'Software Engineering BSc' but only an optional unit for the course 'Web Technology BSc'. I've used flags for that purpose. A student is enrolled on an award so I need to get a complete list of core and optional units (bearing in mind that a student chooses 1 out of many possible optional units). Also, these units have events, e.g, a lecture, workshop or seminar, etc. and those events have sessions or instances of events where students enrolled on that particular unit are required to attend, and those attendances are stored in a separate table to form a register. So I need a hierarchy of expanding the tables something like this I guess: Awards - Students - Units - Sessions - Attendances Any help with this would be appreciated... It's blowing my mind and I'm really close to going insane! My tutor didn't spot I'd got it wrong when I showed my original data model to him and it's due in next week! Thank you :D

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• Generate an ID via COM interop

  - by Erik van Brakel

  At the moment, we've got an unmaintanable ball of code which offers an interface to a third party application. The third party application has a COM assembly which MUST be used to create new entries. This process involves two steps: generate a new object (basically an ID), and update that object with new field values. Because COM interop is so slow, we only use that to generate the ID (and related objects) in the database. The actual update is done using a regular SQL query. What I am trying to figure out if it's possible to use NHibernate to do some of the heavy lifting for us, without bypassing the COM assembly. Here's the code for saving something to the database as I envision it: using(var s = sessionFactory.OpenSession()) using(var t = s.BeginTransaction()) { MyEntity entity = new MyEntity(); s.Save(entity); t.Commit(); } Regular NH code I'd say. Now, this is where it gets tricky. I think I have to supply my own implementation of NHibernate.Id.IIdentifierGenerator which calls the COM assembly in the Generate method. That's not a problem. What IS a problem is that the COM assembly requires initialisation, which does take a bit of time. It also doesn't like multiple instances in the same process, for some reason. What I would like to know is if there's a way to properly access an external service in the generator code. I'm free to use any technique I want, so if it involves something like an IoC container that's no problem. The thing I am looking for is where exactly to hook-up my code so I can access the things I need in my generator, without having to resort to using singletons or other nasty stuff.

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• MySQL database design question

  - by Greelmo

  I'm trying to weigh the pros and cons of a database design, and would like to get some feedback as to the best approach. Here is the situation: I have users of my system that have only a few required items (username, password). They can then supply a lot of optional information. This optional information continues to grow as the system grows, so I want to do it in such a way that adding new optional information is easy. Currently, I have a separate table for each piece of information. For example, there's a table called 'names' that holds 'user_id', 'first_name', and 'last_name'. There's 'address', 'occupation', etc. You get the drift. In most cases, when I talk to my database, I'm looking only for users with one particular qualifier (name, address, etc.). However, there are instances when I want to see what information a user has set. The 'edit account' page, for example, must run queries for each piece of information it wants. Is this wasteful? Is there a way I can structure my queries or my database to make it so I never have to do one query for each piece of information like that without getting my tables to huge? If i want to add 'marital status', how hard will that be if I don't have a one-table-per-attribute system? Thanks in advance.

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• Partial Classes - are they bad design?

  - by dferraro

  Hello, I'm wondering why the 'partial class' concept even exists in .NET. I'm working on an application and we are reading a (actually very good) book relavant to the development platform we are implementing at work. In the book he provides a large code base /wrapper around the platform API and explains how he developed it as he teaches different topics about the platform development. Anyway, long story short - he uses partial classes, all over the place, as a way to fake multiple inheritence in C# (IMO). Why he didnt just split the classes up into multiple ones and use composition is beyond me. He will have 3 'partial class' files to make up his base class, each w/ 3-500 lines of code... And does this several times in his API. Do you find this justifiable? If it were me, I'd have followed the S.R.P. and created multiple classes to handle different required behaviors, then create a base class that has instances of these classes as members (e.g. composition). Why did MS even put partial class into the framework?? They removed the ability to expand/collapse all code at each scope level in C# (this was allowed in C++) because it was obviously just allowing bad habits - partial class is IMO the same thing. I guess my quetion is: Can you explain to me when there would be a legitimate reason to ever use a partial class? I do not mean this to be a rant / war thread. I'm honeslty looking to learn something here. Thanks

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• How to manage multiple python versions ?

  - by Gyom

  short version: how can I get rid of the multiple-versions-of-python nightmare ? long version: over the years, I've used several versions of python, and what is worse, several extensions to python (e.g. pygame, pylab, wxPython...). Each time it was on a different setup, with different OSes, sometimes different architectures (like my old PowerPC mac). Nowadays I'm using a mac (OSX 10.6 on x86-64) and it's a dependency nightmare each time I want to revive script older than a few months. Python itself already comes in three different flavours in /usr/bin (2.5, 2.6, 3.1), but I had to install 2.4 from macports for pygame, something else (cannot remember what) forced me to install all three others from macports as well, so at the end of the day I'm the happy owner of seven (!) instances of python on my system. But that's not the problem, the problem is, none of them has the right (i.e. same set of) libraries installed, some of them are 32bits, some 64bits, and now I'm pretty much lost. For example right now I'm trying to run a three-year-old script (not written by me) which used to use matplotlib/numpy to draw a real-time plot within a rectangle of a wxwidgets window. But I'm failing miserably: py26-wxpython from macports won't install, stock python has wxwidgets included but also has some conflict between 32 bits and 64 bits, and it doesn't have numpy... what a mess ! Obviously, I'm doing things the wrong way. How do you usally cope with all that chaos ?e

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• How should child views of UIScrollView report their bounds for contentSize?

  - by Mike

  I'm looking more for advice on the correct design for a view. What I have is a UIScrollView that contains one or more custom Views I have created. My problem is, who reports to the scrollview what it's contentSize should be? I have the following: UIView +-UIScrollView +-CustomView 1 with dynamic height depending on data +-CustomView 2 with dynamic Height depending on data The UIViewController creates new instances of the custom views with data and then adds them as subviews to the UIScrollView. The problem I'm having is how to set the value of the scrollview's contentSize? Right now, I'm not doing that and the contents of the scrollview are clipped with no scrolling possible. Should the custom view call [parent setContentSize:] in its drawRect:? Should the UIViewController query the custom view after creation to get its bounds and then call setContentSize? Should I subclass the UIScrollView to override addSubView to query each subview's height? Is there something else I'm missing? I hope I explained that properly. I'm new to this and still getting a handle on things.

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• Why can't I wrap the ServletRequest when trying to capture JSP Output

  - by Patrick Cornelissen

  I am trying to dispatch in a servlet request handler to the JSP processor and capture the content of it. I am providing wrapper instances for the ServletRequest and ServletResponse, they implement the corresponding HTTPServletRequest/-Response interfaces, so they should be drop-in replacements. All methods are currently passed to the original Servlet Request object (I am planning to modify some of them soon). Additionally I have introduced some new methods. (If you want to see the code: http://code.google.com/p/gloudy/source/browse/trunk/gloudyPortal/src/java/org/gloudy/gloudlet/impl/RenderResponseImpl.java) The HttpServletResponse uses it's own output streams to capture the output. When I try to call request.getRequestDispatcher("/WEB-INF/views/test.jsp").include(request, response); With my request and response wrappers the method returns and no content has been captured. When I tried to pass the original request object it worked! But that's not what I need in the long run... request.getRequestDispatcher("/WEB-INF/views/test.jsp").include(request.getServletRequest(), response); This works. getservletRequest() returns the original Request, given by the servlet container. Does anyone know why this is not working with my wrappers?

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• Dealing with Try/Catch Exceptions in Java bytecode? ("stack height inconsistent")

  - by Cogwirrel

  I am trying to do some error handling in java bytecode. I first tried to implement some catch-like subroutines, where I would check for the error condition, and jump to the appropriate subroutine, a little like: iconst_1 iconst_0 dup ifeq calldiverr goto enddivtest calldiverr: jsr divError enddivtest: idiv ...More instructions... divError: getstatic java/lang/System/out Ljava/io/PrintStream; ldc "Oh dear you divided by 0!" invokevirtual java/io/PrintStream/print(Ljava/lang/String;)V The problem with the above is that when I have multiple instructions that jump to this subroutine, I get an error message when running the bytecode, saying that the stack height is inconsistent. Perhaps using exceptions is the best way to get around this? From some googling I have found that you can create instances of Exception classes and initialise them with something like: new java/lang/Exception dup ldc "exception message!" invokespecial java/lang/Exception/<init>(Ljava/lang/String;)V I have also found that you can throw them with athrow and this seems ok. What is confusing me however is exactly how exceptions are caught. There seems to be a magical "Exception table" which glues the throwing and catching of exceptions together, but I do not know how to define one of these when writing bytecode from scratch (and assembling using Jasmin). Can somebody tell me the secret of creating an exception table? And possibly give me an example of exception handling that will assemble with jasmin?

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• How to build a web crawler to find a specific advert, which is in an iframe loaded by Javascript

  - by ZoFreX

  I'm trying to find all instances of an advert on a website. The advert is in an iframe which is loaded by javascript (it doesn't appear at all if javascript is turned off). Detecting the advert itself is extremely simple, both the name of the flash file and the target of the href always contain a certain string. What would be the best "starting point" for achieving this? At the moment I'm considering an Adobe AIR app, which could crawl the site and examine the DOM to find the ad, and would run javascript and load the content of the iframe. The other option I can think of is using Firefox as the platform (using maybe GreaseMonkey or Selenium? I don't really know how to leverage Firefox like this). Does anyone know of anything suitable to build this, or have any suggestions on using Firefox to do it? Extra details: Being CPU intensive isn't really an issue, nor is anything depending on a browser being open. This doesn't need to run on a headless server, it will be running on a powerful desktop box. OS is also not an issue. It would be advantageous if the crawler loaded each page multiple times, as the advert is in rotation. While the crawler does need to execute the javascript and load the content of the iframe, it does not need to be able to display flash files.

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• Binding type variables that only occur in assertions

  - by Giuseppe Maggiore

  Hi! I find it extremely difficult to describe my problem, so here goes nothing: I have a bunch of assertions on the type of a function. These assertions rely on a type variable that is not used for any parameter of the function, but is only used for internal bindings. Whenever I use this function it does not compile because, of course, the compiler has no information from which to guess what type to bind my type variable. Here is the code: {-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, FlexibleInstances, UndecidableInstances, FlexibleContexts, EmptyDataDecls, ScopedTypeVariables, TypeOperators, TypeSynonymInstances #-} class C a a' where convert :: a -> a' class F a b where apply :: a -> b class S s a where select :: s -> a data CInt = CInt Int instance S (Int,String) Int where select (i,_) = i instance F Int CInt where apply = CInt f :: forall s a b . (S s a, F a b) => s -> b f s = let v = select s :: a y = apply v :: b in y x :: Int x = f (10,"Pippo") And here is the generated error: FunctorsProblems.hs:21:4: No instances for (F a Int, S (t, [Char]) a) arising from a use of `f' at FunctorsProblems.hs:21:4-17 Possible fix: add an instance declaration for (F a Int, S (t, [Char]) a) In the expression: f (10, "Pippo") In the definition of `x': x = f (10, "Pippo") Failed, modules loaded: none. Prelude>

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• Dynamic columns/rows

  - by Fuego DeBassi

  Wondering--does anyone know of any good articles explaining the CSS technique allowing multiple instances of a class to flow down the page relative to the items above it. Not explaining it that well. Veerle' Pierter's does it on this page: http://veerle.duoh.com/belgiangraphicdesign Although I'm not sure I want to use a technique like her's that requires entering of the height per element via her EE installation. I made a little graphic of what I am trying to acheive; http://cl.ly/71163510ce9d294f9f33 The key is I need a robust technique for doing it. Something where the markup could be as simple as; <div class="box"> Number 1 </div> <div class="box"> Number 2 </div> <div class="box"> Number 3 </div> <div class="box"> Number 4 </div> <div class="box"> Number 5 </div> ... Would love any pointers in the right direction.

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• Can the Singleton be replaced by Factory?

  - by lostiniceland

  Hello Everyone There are already quite some posts about the Singleton-Pattern around, but I would like to start another one on this topic since I would like to know if the Factory-Pattern would be the right approach to remove this "anti-pattern". In the past I used the singleton quite a lot, also did my fellow collegues since it is so easy to use. For example, the Eclipse IDE or better its workbench-model makes heavy usage of singletons as well. It was due to some posts about E4 (the next big Eclipse version) that made me start to rethink the singleton. The bottom line was that due to this singletons the dependecies in Eclipse 3.x are tightly coupled. Lets assume I want to get rid of all singletons completely and instead use factories. My thoughts were as follows: hide complexity less coupling I have control over how many instances are created (just store the reference I a private field of the factory) mock the factory for testing (with Dependency Injection) when it is behind an interface In some cases the factories can make more than one singleton obsolete (depending on business logic/component composition) Does this make sense? If not, please give good reasons for why you think so. An alternative solution is also appreciated. Thanks Marc

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• C# reference collection for storing reference types

  - by ivo s

  I like to implement a collection (something like List<T>) which would hold all my objects that I have created in the entire life span of my application as if its an array of pointers in C++. The idea is that when my process starts I can use a central factory to create all objects and then periodically validate/invalidate their state. Basically I want to make sure that my process only deals with valid instances and I don't re-fetch information I already fetched from the database. So all my objects will basically be in one place - my collection. A cool thing I can do with this is avoid database calls to get data from the database if I already got it (even if I updated it after retrieval its still up-to-date if of course some other process didn't update it but that a different concern). I don't want to be calling new Customer("James Thomas"); again if I initted James Thomas already sometime in the past. Currently I will end up with multiple copies of the same object across the appdomain - some out of sync other in sync and even though I deal with this using timestamp field on the MSSQL server I'd like to keep only one copy per customer in my appdomain (if possible process would be better). I can't use regular collections like List or ArrayList for example because I cannot pass parameters by their real local reference to the their existing Add() methods where I'm creating them using ref so that's not to good I think. So how can this be implemented/can it be implemented at all ? A 'linked list' type of class with all methods working with ref & out params is what I'm thinking now but it may get ugly pretty quickly. Is there another way to implement such collection like RefList<T>.Add(ref T obj)? So bottom line is: I don't want re-create an object if I've already created it before during the entire application life unless I decide to re-create it explicitly (maybe its out-of-date or something so I have to fetch it again from the db). Is there alternatives maybe ?

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• Naming multi-instance performance counters in .NET

  - by Roger Lipscombe

  Most multiple instance performance counters in Windows seem to automatically(?) have a #n on the end if there's more than one instance with the same name. For example: if, in Perfmon, you look under the Process category, you'll see: ... dwm explorer explorer#1 ... I have two explorer.exe processes, so the second counter has #1 appended to its name. When I attempt to do this in a .NET application: I can create the category, and register the instance (using the PerformanceCounterCategory.Create that takes a CounterCreationDataCollection). I can open the counter for write and write to it. When I open the counter a second time, it opens the same counter. This means that I have two applications fighting over the counters. The documentation for PerformanceCounter.InstanceName states that # is not allowed in the name. So: how do I have multiple-instance performance counters that are actually multiple instance? And where the second (and subsequent) instances get #n appended to the name? That is: I know that I can put the process ID (e.g.) on the instance name. This works, but has the unfortunate side effect that restarting the process results in a new PID, and Perfmon continues monitoring the old counter.

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