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• Code Golf: Morse code

  - by LiraNuna

  The challenge The shortest code by character count, that will input a string using only alphabetical characters (upper and lower case), numbers, commas, periods and question mark, and returns a representation of the string in Morse code. The Morse code output should consist of a dash (-, ascii 0x2D) for a long beep (aka 'dah') and a dot (., ascii 0x2E) for short beep (aka 'dit'). Each letter should be separated by a space (' ', ascii 0x20), and each word should be separated by a forward slash (/, ascii 0x2F). Morse code table: Test cases: Input: Hello world Output: .... . .-.. .-.. --- / .-- --- .-. .-.. -.. Input: Hello, Stackoverflow. Output: .... . .-.. .-.. --- --..-- / ... - .- -.-. -.- --- ...- . .-. ..-. .-.. --- .-- .-.-.- Code count includes input/output (i.e full program).

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• split string error in a compiled VB.NET class

  - by Andy Payne

  I'm having some trouble compiling some VB code I wrote to split a string based on a set of predefined delimeters (comma, semicolon, colon, etc). I have successfully written some code that can be loaded inside a custom VB component (I place this code inside a VB.NET component in a plug-in called Grasshopper) and everything works fine. For instance, let's say my incoming string is "123,456". When I feed this string into the VB code I wrote, I get a new list where the first value is "123" and the second value is "456". However, I have been trying to compile this code into it's own class so I can load it inside Grasshopper separately from the standard VB component. When I try to compile this code, it isn't separating the string into a new list with two values. Instead, I get a message that says "System.String []". Do you guys see anything wrong in my compile code? You can find an screenshot image of my problem at the following link: click to see image This is the VB code for the compiled class: Public Class SplitString Inherits GH_Component Public Sub New() MyBase.New("Split String", "Split", "Splits a string based on delimeters", "FireFly", "Serial") End Sub Public Overrides ReadOnly Property ComponentGuid() As System.Guid Get Return New Guid("3205caae-03a8-409d-8778-6b0f8971df52") End Get End Property Protected Overrides ReadOnly Property Internal_Icon_24x24() As System.Drawing.Bitmap Get Return My.Resources.icon_splitstring End Get End Property Protected Overrides Sub RegisterInputParams(ByVal pManager As Grasshopper.Kernel.GH_Component.GH_InputParamManager) pManager.Register_StringParam("String", "S", "Incoming string separated by a delimeter like a comma, semi-colon, colon, or forward slash", False) End Sub Protected Overrides Sub RegisterOutputParams(ByVal pManager As Grasshopper.Kernel.GH_Component.GH_OutputParamManager) pManager.Register_StringParam("Tokenized Output", "O", "Tokenized Output") End Sub Protected Overrides Sub SolveInstance(ByVal DA As Grasshopper.Kernel.IGH_DataAccess) Dim myString As String DA.GetData(0, myString) myString = myString.Replace(",", "|") myString = myString.Replace(":", "|") myString = myString.Replace(";", "|") myString = myString.Replace("/", "|") myString = myString.Replace(")(", "|") myString = myString.Replace("(", String.Empty) myString = myString.Replace(")", String.Empty) Dim parts As String() = myString.Split("|"c) DA.SetData(0, parts) End Sub End Class This is the custom VB code I created inside Grasshopper: Private Sub RunScript(ByVal myString As String, ByRef A As Object) myString = myString.Replace(",", "|") myString = myString.Replace(":", "|") myString = myString.Replace(";", "|") myString = myString.Replace("/", "|") myString = myString.Replace(")(", "|") myString = myString.Replace("(", String.Empty) myString = myString.Replace(")", String.Empty) Dim parts As String() = myString.Split("|"c) A = parts End Sub ' ' End Class

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• C# string.Split() Matching Both Slashes?

  - by Sheep Slapper

  I've got a .NET 3.5 web application written in C# doing some URL rewriting that includes a file path, and I'm running into a problem. When I call string.Split('/') it matches both '/' and '\' characters. Is that... supposed to happen? I assumed that it would notice that the ASCII values were different and skip it, but it appears that I'm wrong. // url = 'someserver.com/user/token/files\subdir\file.jpg string[] buffer = url.Split('/'); The above code gives a string[] with 6 elements in it... which seems counter intuitive. Is there a way to force Split() to match ONLY the forward slash? Right now I'm lucky, since the offending slashes are at the end of the URL, I can just concatenate the rest of the elements in the string[], but it's a lot of work for what we're doing, and not a great solution to the underlying problem. Anyone run into this before? Have a simple answer? I appreciate it!

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• nested include in php

  - by aeonsleo

  The directory structure: C:/wamp/www/application/model/data_access/data_object.php C:/wamp/www/application/model/users/user.class.php C:/wamp/www/application/controller/projects.php C:/wamp/www/application/controller/links/links.php I have 2 php files data_object.php and user.class.php Now user.class.php has an include statement for data_object.php wchih is relative to user.class.php.These two files are under different directory hierarchy. Now I have to include this user.class.php in various files (like projects.php, links.php-which themselves are under different hierarchy) whenever i want to create a User() object. The problem is the relative path for file inclusion of data_object.php does work for say projects.php but if i open links.php the error message says it could not open file data_object.php in user.class.php. What i think is for relative inclusion of data_object.php it is considering the path of the file in which user.class.php is included. I am facing such problems in more than one scenarios I have to keep my directory structure the way it is but have to find a way to work with nested includes. I used Document root of session it give root path as C:/wamp/www/ i appended the path for data_object.php include but this is not working. (note: the forward slash is present after www) I am currently running on wamp server's localhost but after completion i have to host the solution on a domain. Pls help

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• How to use javascript class from within document ready

  - by Richard

  Hi, I have this countdown script wrapped as an object located in a separate file Then when I want to setup a counter, the timeout function in the countdown class can not find the object again that I have setup within the document ready. I sort of get that everything that is setup in the document ready is convined to that scope, however it is possible to call functions within other document ready´s. Does anyone has a solution on how I could setup multiple counters slash objects. Or do those basic javascript classes have to become plugins This is some sample code on how the class begins function countdown(obj) { this.obj = obj; this.Div = "clock"; this.BackColor = "white"; this.ForeColor = "black"; this.TargetDate = "12/31/2020 5:00 AM"; this.DisplayFormat = "%%D%% Days, %%H%% Hours, %%M%% Minutes, %%S%% Seconds."; this.CountActive = true; this.DisplayStr; this.Calcage = cd_Calcage; this.CountBack = cd_CountBack; this.Setup = cd_Setup; } thanks, Richard

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• Backreferences syntax in replacement strings (why dollar sign?)

  - by polygenelubricants

  In Java, and it seems in a few other languages, backreferences in the pattern is preceded by a slash (e.g. \1, \2, \3, etc), but in a replacement string it's preceded by a dollar sign (e.g. $1, $2, $3, and also $0). Here's a snippet to illustrate: System.out.println( "left-right".replaceAll("(.*)-(.*)", "\\2-\\1") // WRONG!!! ); // prints "2-1" System.out.println( "left-right".replaceAll("(.*)-(.*)", "$2-$1") // CORRECT! ); // prints "right-left" System.out.println( "You want million dollar?!?".replaceAll("(\\w*) dollar", "US\\$ $1") ); // prints "You want US$ million?!?" System.out.println( "You want million dollar?!?".replaceAll("(\\w*) dollar", "US$ \\1") ); // throws IllegalArgumentException: Illegal group reference Questions: Is the use of $ for backreferences in replacement strings unique to Java? If not, what language started it? What flavors use it and what don't? Why is this a good idea? Why not stick to the same pattern syntax? Wouldn't that lead to a more cohesive and an easier to learn language? Wouldn't the syntax be more streamlined if statements 1 and 4 in the above were the "correct" ones instead of 2 and 3?

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• Get the signed/unsigned variant of an integer template parameter without explicit traits

  - by Blair Holloway

  I am looking to define a template class whose template parameter will always be an integer type. The class will contain two members, one of type T, and the other as the unsigned variant of type T -- i.e. if T == int, then T_Unsigned == unsigned int. My first instinct was to do this: template <typename T> class Range { typedef unsigned T T_Unsigned; // does not compile public: Range(T min, T_Unsigned range); private: T m_min; T_Unsigned m_range; }; But it doesn't work. I then thought about using partial template specialization, like so: template <typename T> struct UnsignedType {}; // deliberately empty template <> struct UnsignedType<int> { typedef unsigned int Type; }; template <typename T> class Range { typedef UnsignedType<T>::Type T_Unsigned; /* ... */ }; This works, so long as you partially specialize UnsignedType for every integer type. It's a little bit of additional copy-paste work (slash judicious use of macros), but serviceable. However, I'm now curious - is there another way of determining the signed-ness of an integer type, and/or using the unsigned variant of a type, without having to manually define a Traits class per-type? Or is this the only way to do it?

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• What can I do about ambigous wildcard patterns in Struts?

  - by Hanno Fietz

  I have a problem finding the right wildcard pattern to extract parts of my URL into action parameters in Struts. This is how I set up the action. The intent of the pattern is to capture the last two path elements and then everything that might precede them. <action name="**/*/*" class="com.example.ObjectAction"> <param name="filter">{1}</param> <param name="type">{2}</param> <param name="id">{3}</param> </action> Calling it with the URL channels/123/transmissions/456 I get the following result (the action just sets the input parameters on a POJO and returns that as XML): <result> <filter>channels/123/transmissions</filter> <id/> <type>456</type> </result> It should be: <result> <filter>channels/123</filter> <id>456</id> <type>transmissions</type> </result> Now, because ** matches all characters including the slash, I guess my pattern allows more than one way to match the URL, and Struts happens to pick one that leaves the id empty. Is the behaviour for multiple possible matches defined somewhere? Can I make the pattern less ambigous? Are there alternative ways of doing this? I'm running Struts 2.0.8. Upgrading to 2.1.9 would give me regex matching, but I got into trouble with Struts' dependencies and my OSGi environment when I went past 2.0.8, so I'd like to stick to that version for now.

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• Facebook like button issue.

  - by Ross Hale

  Hello community, We're having some trouble getting our like button to work. It seemed to work last week but suddenly it's stopped working. Basically when clicking "Like", we get an error saying: You failed to provide a valid list of administators. You need to supply the administors using either a "fb:app_id" meta tag, or using a "fb:admins" meta tag to specify a comma-delimited list of Facebook users. Our section looks like this: <html xmlns="http://www.w3.org/1999/xhtml" xmlns:og="http://opengraphprotocol.org/schema/" xmlns:fb="http://www.facebook.com/2008/fbml" xml:lang="en" lang="en"> <head> <meta property="fb:app_id" content="number"/> <meta property="fb:admins" content="number"/> <meta property="og:title" content="title"/> <meta property="og:type" content="website"/> <meta property="og:url" content="url with trailing slash"/> <meta property="og:image" content="url to image"/> <meta property="og:site_name" content="Site Name"/> </head> Help?

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• New Rails deployment half working...not sure why?

  - by Meltemi

  I'm in the final stages of going round trip through the entire Rails cycle: development - test - production (on an external server). I'm very close...but seeing some errors with the production version and don't know enough about Rails' "magic" to troubleshoot it yet... all seems well and I can load my app by going to www.mydomain.com/rails and it seems to work...I can interact with my app and create new objects in my database. However, when I go to www.mydomain.com/rails/ (difference is the trailing slash) i get a webpage that just says "Index from public" on it?!? I don't know where that's coming from? index.html is long removed from public. this may or may not be related to why I can't access, say, the first record in one of my classes by calling its controller like so: www.mydomain.com/rails/mycontroller/1 . and yes, there are records in the database. anyway, something's askew. it works fine on development box. but, only half working on production server. anyone know what might be causing this? this app is running on the server box (not development) Installed Passenger on server to serve app via Apache modified my httpd.conf with Passenger's stuff (headache but finally got it to respond) loaded schema into the production database: rake db:schema:load RAILS_ENV=production

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• XPath _relative_ to given element in HTMLUnit/Groovy?

  - by Misha Koshelev

  Dear All: I would like to evaluate an XPath expression relative to a given element. I have been reading here: http://www.w3schools.com/xpath/default.asp And it seems like one of the syntaxes below should work (esp no leading slash or descendant:) However, none seem to work in HTMLUnit. Any help much appreciated (oh this is a groovy script btw). Thank you! http://htmlunit.sourceforge.net/ http://groovy.codehaus.org/ Misha #!/usr/bin/env groovy import com.gargoylesoftware.htmlunit.WebClient def html=""" <html><head><title>Test</title></head> <body> <div class='levelone'> <div class='leveltwo'> <div class='levelthree' /> </div> <div class='leveltwo'> <div class='levelthree' /> <div class='levelthree' /> </div> </div> </body> </html> """ def f=new File('/tmp/test.html') if (f.exists()) { f.delete() } def fos=new FileOutputStream(f) fos<<html def webClient=new WebClient() def page=webClient.getPage('file:///tmp/test.html') def element=page.getByXPath("//div[@class='levelone']") assert element.size()==1 element=page.getByXPath("div[@class='levelone']") assert element.size()==0 element=page.getByXPath("/div[@class='levelone']") assert element.size()==0 element=page.getByXPath("descendant:div[@class='levelone']") // this gives namespace error assert element.size()==0 Thank you!!!

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• How to do an additional search on archive in rails if record not found, by extending model?

  - by Nick Gorbikoff

  Hello, I was wondering if somebody knows an elegant solution to the following: Suppose I have a table that holds orders, with a bunch of data. So I'm at 1M records, and searches begin to take time. So I want to speed it up by archiving some data that is more than 3 years old - saving it into a table called orders-archive, and then purging them from the orders table. So if we need to research something or customer wants to pull older information - they still can, but 99% of the lookups are done on the orders no older than a year and a half - so there is no reason to keep looking through older data all the time. These move & purge operations can be then croned to be done on a weekly basis. I already did some tests and I know that I will slash my search times by about 4 times. So far so good, right? However I was thinking about how to implement older archival lookups and the only reasonable thing I can think of is some sort of if-else If not found in orders, do a search in orders-archive. However - I have about 20 tables that I want to archive and god knows how many searches / finds are done through out the code, that I don't want to modify. So I was wondering if there is an elegant rails-way solution to this problem, by extending a model somehow? Has anyone dealt with similar case before? Thank you.

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• Visual Studio: Collapse Methods, but not Comments (Summary etc.)

  - by Alex

  Hello, is there a way (settings? "macro"? extension?) that I can simply toggle outlining so that only the using section and my methods collapse to their signature line, but my comments (summary and double slash comments) and classes stay expanded? Examples: 1) Uncollapsed using System; using MachineGun; namespace Animals { /// <summary> /// Angry animal /// Pretty Fast, too /// </summary> public partial class Lion { // // Dead or Alive public Boolean Alive; /// <summary> /// Bad bite /// </summary> public PieceOfAnimal Bite(Animal animalToBite) { return animalToBite.Shoulder; } /// <summary> /// Fatal bite /// </summary> public PieceOfAnimal Kill(Animal animalToKill) { return animalToKill.Head; } } } 2) Collapsed (the following is my desired result): using[...] namespace Animals { /// <summary> /// Angry animal /// Pretty Fast, too /// </summary> public partial class Lion { // // Dead or Alive public Boolean Alive; /// <summary> /// Bad bite /// </summary> public PieceOfAnimal Bite(Animal animalToBite)[...] /// <summary> /// Fatal bite /// </summary> public PieceOfAnimal Kill(Animal animalToKill)[...] } } This is how I prefer seeing my class files (the collapsed form). I've been doing the collapsing by hand a million times by now and I think there should be a way to automate/customize/extend VS to do it the way I want? Every time I debug/hit a breakpoint, it uncollapses and messes up things. If I collapse via the context menu's collapse to outline etc. it also collapses my comments which isn't desired. Appreciate your help!

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• There is a Default instance of form in VB.Net but not in C#, WHY?

  - by Shekhar_Pro

  I'm just curious to know that there is The (Name) property, which represents the name of the Form class.This property is used within the namespace to uniquely identify the class that the Form is an instance of and, in the case of Visual Basic, is used to access the default instance of the form. Now where this Default Instance come from, why can't C# have a equivalent method to this. Also for example to show a form in C# we do something like this: //Only method Form1 frm = new Form1(); frm.Show(); But in VB.Net we have both ways to do it: //'First common method (used slash because editor wouldn't format it properly) Form1.Show(); //'Second method Dim frm as New Form1(); frm.Show(); My question comes from this first method. What is this Form1, is it an instance of Form1 or the Form1 class itself. Now as i mentioned above the Form name is the Default instance in VB.Net. But we also know that Form1 is a class defined in Designer so how can the names be same for both the Instance and class name. If Form1 is Class then there is no (Static\Shared) method named Show(). So where does this method come from. And finally why C# can't have an equivalent of this. If there some mistake in my question Please let me know *I've checked this on stackoverflow, but couldn't find an answer to this.If you do find then please give a link to it.*

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• c# winforms events restore textbox contents on escape

  - by aj3jr

  Using c# in 2008 Express. I have a textbox containing a path. I append a "\" at the end on Leave Event. If the user presses 'Escape' key I want the old contents to be restored. When I type over all the text and press 'Escape' I hear a thump and the old text isn't restored. Here what I have so far ... public string _path; public string _oldPath; this.txtPath.KeyPress += new System.Windows.Forms.KeyPressEventHandler(txtPath_CheckKeys); this.txtPath.Enter +=new EventHandler(txtPath_Enter); this.txtPath.LostFocus += new EventHandler(txtPath_LostFocus); public void txtPath_CheckKeys(object sender, KeyPressEventArgs kpe) { if (kpe.KeyChar == (char)27) { _path = _oldPath; } } public void txtPath_Enter(object sender, EventArgs e) { //AppendSlash(sender, e); _oldPath = _path; } void txtPath_LostFocus(object sender, EventArgs e) { //throw new NotImplementedException(); AppendSlash(sender, e); } public void AppendSlash(object sender, EventArgs e) { //add a slash to the end of the txtPath string on ANY change except a restore this.txtPath.Text += @"\"; } Thanks in advance,

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• Implemeting web-based autocomplete for structured input

  - by ravigad

  I am looking to implement web-based autocomplete for structured commands. So, for example, suppose I was trying to implement a web-based Windows command line with autocomplete, in such a case I would want to suggest all the available commands, then, once a user selects a command, all the options for that command, then if a user enters a switch (say '-' dash or '/' slash) then offer all the switches for that command and all the relevant values that can follow, and so on. All from the same text input box. If you have used version 4.0 of JIRA, I am thinking of something similar to the JQL search input box that they have implemented. I have not managed to find any tutorials that look at this scenario end-to-end (which is a shame, because it would be great to see more applications that do this). What I am looking for is some guidance on the steps needed to implement this solution: Do you have any experience implementing such a solution and if so what components did you use? Would you use a framework such as ANTLR to provide the available options to the end user? If not what would do? Sorry for raising such a general question, but my main problem is working out how the pieces fit together as opposed to, say, how to do autocomplete or how to parse/tokenize an input command...

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• Multi-tenant ASP.NET MVC – Introduction

  - by zowens

  I’ve read a few different blogs that talk about multi-tenancy and how to resolve some of the issues surrounding multi-tenancy. What I’ve come to realize is that these implementations overcomplicate the issues and give only a muddy implementation! I’ve seen some really illogical code out there. I have recently been building a multi-tenancy framework for internal use at eagleenvision.net. Through this process, I’ve realized a few different techniques to make building multi-tenant applications actually quite easy. I will be posting a few different entries over the issue and my personal implementation. In this first post, I will discuss what multi-tenancy means and how my implementation will be structured.   So what’s the problem? Here’s the deal. Multi-tenancy is basically a technique of code-reuse of web application code. A multi-tenant application is an application that runs a single instance for multiple clients. Here the “client” is different URL bindings on IIS using ASP.NET MVC. The problem with different instances of the, essentially, same application is that you have to spin up different instances of ASP.NET. As the number of running instances of ASP.NET grows, so does the memory footprint of IIS. Stack Exchange shifted its architecture to multi-tenancy March. As the blog post explains, multi-tenancy saves cost in terms of memory utilization and physical disc storage. If you use the same code base for many applications, multi-tenancy just makes sense. You’ll reduce the amount of work it takes to synchronize the site implementations and you’ll thank your lucky stars later for choosing to use one application for multiple sites. Multi-tenancy allows the freedom of extensibility while relying on some pre-built code.   You’d think this would be simple. I have actually seen a real lack of reference material on the subject in terms of ASP.NET MVC. This is somewhat surprising given the number of users of ASP.NET MVC. However, I will certainly fill the void ;). Implementing a multi-tenant application takes a little thinking. It’s not straight-forward because the possibilities of implementation are endless. I have yet to see a great implementation of a multi-tenant MVC application. The only one that comes close to what I have in mind is Rob Ashton’s implementation (all the entries are listed on this page). There’s some really nasty code in there… something I’d really like to avoid. He has also written a library (MvcEx) that attempts to aid multi-tenant development. This code is even worse, in my honest opinion. Once I start seeing Reflection.Emit, I have to assume the worst :) In all seriousness, if his implementation makes sense to you, use it! It’s a fine implementation that should be given a look. At least look at the code. I will reference MvcEx going forward as a comparison to my implementation. I will explain why my approach differs from MvcEx and how it is better or worse (hopefully better).   Core Goals of my Multi-Tenant Implementation The first, and foremost, goal is to use Inversion of Control containers to my advantage. As you will see throughout this series, I pass around containers quite frequently and rely on their use heavily. I will be using StructureMap in my implementation. However, you could probably use your favorite IoC tool instead. <RANT> However, please don’t be stupid and abstract your IoC tool. Each IoC is powerful and by abstracting the capabilities, you’re doing yourself a real disservice. Who in the world swaps out IoC tools…? No one!</RANT> (It had to be said.) I will outline some of the goodness of StructureMap as we go along. This is really an invaluable tool in my tool belt and simple to use in my multi-tenant implementation. The second core goal is to represent a tenant as easily as possible. Just as a dependency container will be a first-class citizen, so will a tenant. This allows us to easily extend and use tenants. This will also allow different ways of “plugging in” tenants into your application. In my implementation, there will be a single dependency container for a single tenant. This will enable isolation of the dependencies of the tenant. The third goal is to use composition as a means to delegate “core” functions out to the tenant. More on this later.   Features In MvcExt, “Modules” are a code element of the infrastructure. I have simplified this concept and have named this “Features”. A feature is a simple element of an application. Controllers can be specified to have a feature and actions can have “sub features”. Each tenant can select features it needs and the other features will be hidden to the tenant’s users. My implementation doesn’t require something to be a feature. A controller can be common to all tenants. For example, (as you will see) I have a “Content” controller that will return the CSS, Javascript and Images for a tenant. This is common logic to all tenants and shouldn’t be hidden or considered a “feature”; Content is a core component.   Up next My next post will be all about the code. I will reveal some of the foundation to the way I do multi-tenancy. I will have posts dedicated to Foundation, Controllers, Views, Caching, Content and how to setup the tenants. Each post will be in-depth about the issues and implementation details, while adhering to my core goals outlined in this post. As always, comment with questions of DM me on twitter or send me an email.

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• Validation in Silverlight

  - by Timmy Kokke

  Getting started with the basics Validation in Silverlight can get very complex pretty easy. The DataGrid control is the only control that does data validation automatically, but often you want to validate your own entry form. Values a user may enter in this form can be restricted by the customer and have to fit an exact fit to a list of requirements or you just want to prevent problems when saving the data to the database. Showing a message to the user when a value is entered is pretty straight forward as I’ll show you in the following example.     This (default) Silverlight textbox is data-bound to a simple data class. It has to be bound in “Two-way” mode to be sure the source value is updated when the target value changes. The INotifyPropertyChanged interface must be implemented by the data class to get the notification system to work. When the property changes a simple check is performed and when it doesn’t match some criteria an ValidationException is thrown. The ValidatesOnExceptions binding attribute is set to True to tell the textbox it should handle the thrown ValidationException. Let’s have a look at some code now. The xaml should contain something like below. The most important part is inside the binding. In this case the Text property is bound to the “Name” property in TwoWay mode. It is also told to validate on exceptions. This property is false by default.   <StackPanel Orientation="Horizontal"> <TextBox Width="150" x:Name="Name" Text="{Binding Path=Name, Mode=TwoWay, ValidatesOnExceptions=True}"/> <TextBlock Text="Name"/> </StackPanel>   The data class in this first example is a very simplified person class with only one property: string Name. The INotifyPropertyChanged interface is implemented and the PropertyChanged event is fired when the Name property changes. When the property changes a check is performed to see if the new string is null or empty. If this is the case a ValidationException is thrown explaining that the entered value is invalid.   public class PersonData:INotifyPropertyChanged { private string _name; public string Name { get { return _name; } set { if (_name != value) { if(string.IsNullOrEmpty(value)) throw new ValidationException("Name is required"); _name = value; if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Name")); } } } public event PropertyChangedEventHandler PropertyChanged=delegate { }; } The last thing that has to be done is letting binding an instance of the PersonData class to the DataContext of the control. This is done in the code behind file. public partial class Demo1 : UserControl { public Demo1() { InitializeComponent(); this.DataContext = new PersonData() {Name = "Johnny Walker"}; } }   Error Summary In many cases you would have more than one entry control. A summary of errors would be nice in such case. With a few changes to the xaml an error summary, like below, can be added.           First, add a namespace to the xaml so the control can be used. Add the following line to the header of the .xaml file. xmlns:Controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data.Input"   Next, add the control to the layout. To get the result as in the image showed earlier, add the control right above the StackPanel from the first example. It’s got a small margin to separate it from the textbox a little.   <Controls:ValidationSummary Margin="8"/>   The ValidationSummary control has to be notified that an ValidationException occurred. This can be done with a small change to the xaml too. Add the NotifyOnValidationError to the binding expression. By default this value is set to false, so nothing would be notified. Set the property to true to get it to work.   <TextBox Width="150" x:Name="Name" Text="{Binding Name, Mode=TwoWay, ValidatesOnExceptions=True, NotifyOnValidationError=True}"/>   Data annotation Validating data in the setter is one option, but not my personal favorite. It’s the easiest way if you have a single required value you want to check, but often you want to validate more. Besides, I don’t consider it best practice to write logic in setters. The way used by frameworks like WCF Ria Services is the use of attributes on the properties. Instead of throwing exceptions you have to call the static method ValidateProperty on the Validator class. This call stays always the same for a particular property, not even when you change the attributes on the property. To mark a property “Required” you can use the RequiredAttribute. This is what the Name property is going to look like:   [Required] public string Name { get { return _name; } set { if (_name != value) { Validator.ValidateProperty(value, new ValidationContext(this, null, null){ MemberName = "Name" }); _name = value; if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Name")); } } }   The ValidateProperty method takes the new value for the property and an instance of ValidationContext. The properties passed to the constructor of the ValidationContextclass are very straight forward. This part is the same every time. The only thing that changes is the MemberName property of the ValidationContext. Property has to hold the name of the property you want to validate. It’s the same value you provide the PropertyChangedEventArgs with. The System.ComponentModel.DataAnnotation contains eight different validation attributes including a base class to create your own. They are: RequiredAttribute Specifies that a value must be provided. RangeAttribute The provide value must fall in the specified range. RegularExpressionAttribute Validates is the value matches the regular expression. StringLengthAttribute Checks if the number of characters in a string falls between a minimum and maximum amount. CustomValidationAttribute Use a custom method to validate the value. DataTypeAttribute Specify a data type using an enum or a custom data type. EnumDataTypeAttribute Makes sure the value is found in a enum. ValidationAttribute A base class for custom validation attributes All of these will ensure that an validation exception is thrown, except the DataTypeAttribute. This attribute is used to provide some additional information about the property. You can use this information in your own code.   [Required] [Range(0,125,ErrorMessage = "Value is not a valid age")] public int Age {   It’s no problem to stack different validation attributes together. For example, when an Age is required and must fall in the range from 0 to 125:   [Required, StringLength(255,MinimumLength = 3)] public string Name {   Or in one row like this, for a required Name with at least 3 characters and a maximum of 255:   Delayed validation Having properties marked as required can be very useful. The only downside to the technique described earlier is that you have to change the value in order to get it validated. What if you start out with empty an empty entry form? All fields are empty and thus won’t be validated. With this small trick you can validate at the moment the user click the submit button.   <TextBox Width="150" x:Name="NameField" Text="{Binding Name, Mode=TwoWay, ValidatesOnExceptions=True, NotifyOnValidationError=True, UpdateSourceTrigger=Explicit}"/>   By default, when a TwoWay bound control looses focus the value is updated. When you added validation like I’ve shown you earlier, the value is validated. To overcome this, you have to tell the binding update explicitly by setting the UpdateSourceTrigger binding property to Explicit:   private void SubmitButtonClick(object sender, RoutedEventArgs e) { NameField.GetBindingExpression(TextBox.TextProperty).UpdateSource(); }   This way, the binding is in two direction but the source is only updated, thus validated, when you tell it to. In the code behind you have to call the UpdateSource method on the binding expression, which you can get from the TextBox.   Conclusion Data validation is something you’ll probably want on almost every entry form. I always thought it was hard to do, but it wasn’t. If you can throw an exception you can do validation. If you want to know anything more in depth about something I talked about in this article let me know. I might write an entire post to that.

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• OFM 11g: OAM SSO for Forms and ADF Faces

  - by olaf.heimburger

  In my blog entry OFM 11g: Implementing OAM SSO with Forms we set the foundation for providing a complete Single Sign-On solution based on Oracle Access Manager (OAM). This foundation should now be used to combine Forms 11g and ADF Faces 11g applications with a transparent login. The Beginning Before we start, lets re-consider the requirements to achieve the ultimate goal. These are:- Access to the Forms 11g Application must be authenticated by OAM (protected). Access to the ADF Faces 11g Application must be authenticated by OAM (protected). Switching from one application to the other should not result in a re-authentication (aka single sign-on). User identity should be availble to the application without any extra work in the application code. All these are the common requirements for a single sign-on solution. The challenge here is that Forms relies on Oracle AS SSO (OSSO or "the old SSO") while ADF Faces is quite open and can be protected by Oracle AS SSO and Oracle Access Manager SSO (OAM SSO or "the modern SSO"). Both application types can use their own login mechanism. The Forms 11g Application To demonstrate the SSO functionality, we use the standard Forms test (/forms/frmservlet?form=test.fmx). Although this shows nothing specific in the Forms application, it is good enough to demonstrate that it is protected. The ADF Faces 11g Application With ADF 11g you can develop quite a number of useful Faces based applications. Among many features, it comes with the ADF Security feature that provides you with functionality to protect your pages, regions, and even TaskFlows from un-authenticated usage in a declarative way.To demonstrate that functionality a sample application with different access levels plus a login dialog is used. This application comes with a publc page that has protected content (a button). Once you are authenticated for the application, the protected content and some personalisation (the users name) is shown. Protecting Forms 11g As already explained in the OFM 11g: Implementing OAM SSO with Forms, the easiest way to protect a Forms application is to configure it as a OSSO partner application, setup mod_osso, test it, migrate OSSO to OAM SSO with the Upgrade Agent, reconfigure mod_osso, and you are done.Sort of. By default the OAM is configured to run in co-exist mode. This means that a user has to re-authenticate to the Forms application when logged into an OAM SSO application before. To avoid this, you must disable the co-exist mode, for example by using WLST and issue the disableCoexistMode on the OAM server. Protecting ADF Faces 11g To protect an ADF Faces 11g application we have to consider two scenarios: Use a HTTPD server in front of WLS Use WLS without a HTTPD server Both scenarios have their pro's and cons' and we won't get into details and just describe how to configure both. Scenario 1: HTTPD Server with WLS In this scenario we have to setup the environment in some steps:- Configure a WebGate at OAMThis configuration can be done through the OAM console or by a script. No matter which way you choose, the WebGate configuration files will be created for you. Install the OAM WebGate into an HTTPD serverThe type of webgate you need to install depends on you HTTPD server. With Oracle HTTP Server 11g you can use the latest OAM 11g WebGate. With other HTTPD servers you must resort to OAM 10g WebGates. A OAM 11g WebGate can use the pre-created configuration files supplied during the WebGate configuration at OAM. An OAM 10g WebGate asks for the specific configuration and verifies it during installation. Configure the WLS plugin to forward the requests to WLSAgain, depending on your HTTPD Server you have different plugins to forward requests to WLS. With OHS 11g you can use the pre-installed mod_wl_ohs plugin. Its configuration is quite simple and straightforward. Configure an OAM SSPI Provider as a IdentityAsserter in WLS to retrieve the user identifierThis configuration is quite important as it retrieves the user identifier for the next step. If you have a SOA Suite installation within your OFM_HOME, the necessary software is already installed and you only need to setup your Security Realm within WLS.You can do this by pointing your browser to the WLS Console, log in as administrator, select the Security Realm (usually myrealm), and select Providers. We add the OAMIdentityAsserter as the first SSPI Provider. It is important that the Control Flag is set to SUFFICIENT. Every other configuration can be left as is, no changes are necessary here. Configure an OAM Identity Provider to get the real user identityIn OFM 11g: Implementing OAM SSO with Forms we have configured an OID as Identity Store. To get the user identity we need to configure the same OID as an SSPI Provider for WLS. This will retrieve the real user information from OID and creates the JAAS Subject and Principals to be used by any application within WLS.Again, you can do this by pointing your browser to the WLS Console, log in as administrator, select the Security Realm (usually myrealm), and select Providers. Now add the OIDAuthenticator as the second SSPI Provider. It is important that the Control Flag is set to OPTIONAL. After we saved this setup, we need to configure this provider by setting the Provider Specific details to access OID. Scenario 2: WLS only This scenario is a bit easier but requires more work in the WLS setup:- Configure a WebGate at OAMThis configuration can be done through the OAM console or by a script. No matter which way you choose, the WebGate configuration files will be created for you. Configure the OAM SSPI Provider as IdentityAuthenticator to authenticate and set the user identifierWhen using the OAM SSPI Provider as OAMAuthenticator we create it with the Control Flag as SUFFICIENT. Afte saving it, the Provider Specific settings must be configured to allow the OAM SSPI Provider to connect to the OAM Server. Configure an OAM Identity Provider to get the real user identity providerAgain, you can do this by pointing your browser to the WLS Console, log in as administrator, select the Security Realm (usually myrealm), and select Providers. Now add the OIDAuthenticator as the second SSPI Provider. It is important that the Control Flag is set to OPTIONAL. After we saved this setup, we need to configure this provider by setting the Provider Specific details to access OID. Configure ADF 11g Application for OAM Actually, there are no changes to be made within the ADF application. We only need to add the value CLIENT_CERT to the <auth-mode> tag in the <login-config> tag in the web.xml file. Testing To test the configuration, simply point your browser to one of both appliction URLs. OAM should kick in and redirect you to the OAM Login page. After you have entered the correct credentials, access to the URLs is granted and you will see the application. Enjoy!

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• Create PDF document using iTextSharp in ASP.Net 4.0 and MemoryMappedFile

  - by sreejukg

  In this article I am going to demonstrate how ASP.Net developers can programmatically create PDF documents using iTextSharp. iTextSharp is a software component, that allows developers to programmatically create or manipulate PDF documents. Also this article discusses the process of creating in-memory file, read/write data from/to the in-memory file utilizing the new feature MemoryMappedFile. I have a database of users, where I need to send a notice to all my users as a PDF document. The sending mail part of it is not covered in this article. The PDF document will contain the company letter head, to make it more official. I have a list of users stored in a database table named “tblusers”. For each user I need to send customized message addressed to them personally. The database structure for the users is give below. id Title Full Name 1 Mr. Sreeju Nair K. G. 2 Dr. Alberto Mathews 3 Prof. Venketachalam Now I am going to generate the pdf document that contains some message to the user, in the following format. Dear <Title> <FullName>, The message for the user. Regards, Administrator Also I have an image, bg.jpg that contains the background for the document generated. I have created .Net 4.0 empty web application project named “iTextSharpSample”. First thing I need to do is to download the iTextSharp dll from the source forge. You can find the url for the download here. http://sourceforge.net/projects/itextsharp/files/ I have extracted the Zip file and added the itextsharp.dll as a reference to my project. Also I have added a web form named default.aspx to my project. After doing all this, the solution explorer have the following view. In the default.aspx page, I inserted one grid view and associated it with a SQL Data source control that bind data from tblusers. I have added a button column in the grid view with text “generate pdf”. The output of the page in the browser is as follows. Now I am going to create a pdf document when the user clicking on the Generate PDF button. As I mentioned before, I am going to work with the file in memory, I am not going to create a file in the disk. I added an event handler for button by specifying onrowcommand event handler. My gridview source looks like <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSource1" Width="481px" CellPadding="4" ForeColor="#333333" GridLines="None" onrowcommand="Generate_PDF" > ………………………………………………………………………….. ………………………………………………………………………….. </asp:GridView> In the code behind, I wrote the corresponding event handler. protected void Generate_PDF(object sender, GridViewCommandEventArgs e) { // The button click event handler code. // I am going to explain the code for this section in the remaining part of the article } The Generate_PDF method is straight forward, It get the title, fullname and message to some variables, then create the pdf using these variables. The code for getting data from the grid view is as follows // get the row index stored in the CommandArgument property int index = Convert.ToInt32(e.CommandArgument); // get the GridViewRow where the command is raised GridViewRow selectedRow = ((GridView)e.CommandSource).Rows[index]; string title = selectedRow.Cells[1].Text; string fullname = selectedRow.Cells[2].Text; string msg = @"There are some changes in the company policy, due to this matter you need to submit your latest address to us. Please update your contact details / personnal details by visiting the member area of the website. ................................... "; since I don’t want to save the file in the disk, I am going the new feature introduced in .Net framework 4, called Memory-Mapped Files. Using Memory-Mapped mapped file, you can created non-persisted memory mapped files, that are not associated with a file in a disk. So I am going to create a temporary file in memory, add the pdf content to it, then write it to the output stream. To read more about MemoryMappedFile, read this msdn article http://msdn.microsoft.com/en-us/library/dd997372.aspx The below portion of the code using MemoryMappedFile object to create a test pdf document in memory and perform read/write operation on file. The CreateViewStream() object will give you a stream that can be used to read or write data to/from file. The code is very straight forward and I included comment so that you can understand the code. using (MemoryMappedFile mmf = MemoryMappedFile.CreateNew("test1.pdf", 1000000)) { // Create a new pdf document object using the constructor. The parameters passed are document size, left margin, right margin, top margin and bottom margin. iTextSharp.text.Document d = new iTextSharp.text.Document(PageSize.A4, 72,72,172,72); //get an instance of the memory mapped file to stream object so that user can write to this using (MemoryMappedViewStream stream = mmf.CreateViewStream()) { // associate the document to the stream. PdfWriter.GetInstance(d, stream); /* add an image as bg*/ iTextSharp.text.Image jpg = iTextSharp.text.Image.GetInstance(Server.MapPath("Image/bg.png")); jpg.Alignment = iTextSharp.text.Image.UNDERLYING; jpg.SetAbsolutePosition(0, 0); //this is the size of my background letter head image. the size is in points. this will fit to A4 size document. jpg.ScaleToFit(595, 842); d.Open(); d.Add(jpg); d.Add(new Paragraph(String.Format("Dear {0} {1},", title, fullname))); d.Add(new Paragraph("\n")); d.Add(new Paragraph(msg)); d.Add(new Paragraph("\n")); d.Add(new Paragraph(String.Format("Administrator"))); d.Close(); } //read the file data byte[] b; using (MemoryMappedViewStream stream = mmf.CreateViewStream()) { BinaryReader rdr = new BinaryReader(stream); b = new byte[mmf.CreateViewStream().Length]; rdr.Read(b, 0, (int)mmf.CreateViewStream().Length); } Response.Clear(); Response.ContentType = "Application/pdf"; Response.BinaryWrite(b); Response.End(); } Press ctrl + f5 to run the application. First I got the user list. Click on the generate pdf icon. The created looks as follows. Summary: Creating pdf document using iTextSharp is easy. You will get lot of information while surfing the www. Some useful resources and references are mentioned below http://itextsharp.com/ http://www.mikesdotnetting.com/Article/82/iTextSharp-Adding-Text-with-Chunks-Phrases-and-Paragraphs http://somewebguy.wordpress.com/2009/05/08/itextsharp-simplify-your-html-to-pdf-creation/ Hope you enjoyed the article.

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• Interview with Lenz Grimmer about MySQL Connect

  - by Keith Larson

  Keith Larson: Thank you for allowing me to do this interview with you.  I have been talking with a few different Oracle ACEs   about the MySQL Connect Conference. I figured the MySQL community might be missing you as well. You have been very busy with Oracle Linux but I know you still have an eye on the MySQL Community. How have things been?Lenz Grimmer: Thanks for including me in this series of interviews, I feel honored! I've read the other interviews, and really liked them. I still try to follow what's going on over in the MySQL community and it's good to see that many of the familiar faces are still around. Over the course of the 9 years that I was involved with MySQL, many colleagues and contacts turned into good friends and we still maintain close relationships.It's been almost 1.5 years ago that I moved into my new role here in the Linux team at Oracle, and I really enjoy working on a Linux distribution again (I worked for SUSE before I joined MySQL AB in 2002). I'm still learning a lot - Linux in the data center has greatly evolved in so many ways and there are a lot of new and exciting technologies to explore. Keith Larson: What were your thoughts when you heard that Oracle was going to deliver the MySQL Connect conference to the MySQL Community?Lenz Grimmer: I think it's testament to the fact that Oracle deeply cares about MySQL, despite what many skeptics may say. What started as "MySQL Sunday" two years ago has now evolved into a full-blown sub-conference, with 80 sessions at one of the largest corporate IT events in the world. I find this quite telling, not many products at Oracle enjoy this level of exposure! So it certainly makes me feel proud to see how far MySQL has come. Keith Larson: Have you had a chance to look over the sessions? What are your thoughts on them?Lenz Grimmer: I did indeed look at the final schedule.The content committee did a great job with selecting these sessions. I'm glad to see that the content selection was influenced by involving well-known and respected members of the MySQL community. The sessions cover a broad range of topics and technologies, both covering established topics as well as recent developments. Keith Larson: When you get a chance, what sessions do you plan on attending?Lenz Grimmer: I will actually be manning the Oracle booth in the exhibition area on one of these days, so I'm not sure if I'll have a lot of time attending sessions. But if I do, I'd love to see the keynotes and catch some of the sessions that talk about recent developments and new features in MySQL, High Availability and Clustering . Quite a lot has happened and it's hard to keep up with this constant flow of new MySQL releases.In particular, the following sessions caught my attention: MySQL Connect Keynote: The State of the Dolphin Evaluating MySQL High-Availability Alternatives CERN’s MySQL “as a Service” Deployment with Oracle VM: Empowering Users MySQL 5.6 Replication: Taking Scalability and High Availability to the Next Level What’s New in MySQL Server 5.6? MySQL Security: Past and Present MySQL at Twitter: Development and Deployment MySQL Community BOF MySQL Connect Keynote: MySQL Perspectives Keith Larson: So I will ask you just like I have asked the others I have interviewed, any tips that you would give to people for handling the long hours at conferences?Lenz Grimmer: Wear comfortable shoes and make sure to drink a lot! Also prepare a plan of the sessions you would like to attend beforehand and familiarize yourself with the venue, so you can get to the next talk in time without scrambling to find the location. The good thing about piggybacking on such a large conference like Oracle OpenWorld is that you benefit from the whole infrastructure. For example, there is a nice schedule builder that helps you to keep track of your sessions of interest. Other than that, bring enough business cards and talk to people, build up your network among your peers and other MySQL professionals! Keith Larson: What features of the MySQL 5.6 release do you look forward to the most ?Lenz Grimmer: There has been solid progress in so many areas like the InnoDB Storage Engine, the Optimizer, Replication or Performance Schema, it's hard for me to really highlight anything in particular. All in all, MySQL 5.6 sounds like a very promising release. I'm confident it will follow the tradition that Oracle already established with MySQL 5.5, which received a lot of praise even from very critical members of the MySQL community. If I had to name a single feature, I'm particularly and personally happy that the precise GIS functions have finally made it into a GA release - that was long overdue. Keith Larson:  In your opinion what is the best reason for someone to attend this event?Lenz Grimmer: This conference is an excellent opportunity to get in touch with the key people in the MySQL community and ecosystem and to get facts and information from the domain experts and developers that work on MySQL. The broad range of topics should attract people from a variety of roles and relations to MySQL, beginning with Developers and DBAs, to CIOs considering MySQL as a viable solution for their requirements. Keith Larson: You will be attending MySQL Connect and have some Oracle Linux Demos, do you see a growing demand for MySQL on Oracle Linux ?Lenz Grimmer: Yes! Oracle Linux is our recommended Linux distribution and we have a good relationship to the MySQL engineering group. They use Oracle Linux as a base Linux platform for development and QA, so we make sure that MySQL and Oracle Linux are well tested together. Setting up a MySQL server on Oracle Linux can be done very quickly, and many customers recognize the benefits of using them both in combination.Because Oracle Linux is available for free (including free bug fixes and errata), it's an ideal choice for running MySQL in your data center. You can run the same Linux distribution on both your development/staging systems as well as on the production machines, you decide which of these should be covered by a support subscription and at which level of support. This gives you flexibility and provides some really attractive cost-saving opportunities. Keith Larson: Since I am a Linux user and fan, what is on the horizon for  Oracle Linux?Lenz Grimmer: We're working hard on broadening the ecosystem around Oracle Linux, building up partnerships with ISVs and IHVs to certify Oracle Linux as a fully supported platform for their products. We also continue to collaborate closely with the Linux kernel community on various projects, to make sure that Linux scales and performs well on large systems and meets the demands of today's data centers. These improvements and enhancements will then rolled into the Unbreakable Enterprise Kernel, which is the key ingredient that sets Oracle Linux apart from other distributions. We also have a number of ongoing projects which are making good progress, and I'm sure you'll hear more about this at the upcoming OpenWorld conference :) Keith Larson: What is something that more people should be aware of when it comes to Oracle Linux and MySQL ?Lenz Grimmer: Many people assume that Oracle Linux is just tuned for Oracle products, such as the Oracle Database or our Engineered Systems. While it's of course true that we do a lot of testing and optimization for these workloads, Oracle Linux is and will remain a general-purpose Linux distribution that is a very good foundation for setting up a LAMP-Stack, for example. We also provide MySQL RPM packages for Oracle Linux, so you can easily stay up to date if you need something newer than what's included in the stock distribution.One more thing that is really unique to Oracle Linux is Ksplice, which allows you to apply security patches to the running Linux kernel, without having to reboot. This ensures that your MySQL database server keeps up and running and is not affected by any downtime. Keith Larson: What else would you like to add ?Lenz Grimmer: Thanks again for getting in touch with me, I appreciated the opportunity. I'm looking forward to MySQL Connect and Oracle OpenWorld and to meet you and many other people from the MySQL community that I haven't seen for quite some time! Keith Larson:  Thank you Lenz!

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• My Code Kata–A Solution Kata

  - by Glav

  There are many developers and coders out there who like to do code Kata’s to keep their coding ability up to scratch and to practice their skills. I think it is a good idea. While I like the concept, I find them dead boring and of minimal purpose. Yes, they serve to hone your skills but that’s about it. They are often quite abstract, in that they usually focus on a small problem set requiring specific solutions. It is fair enough as that is how they are designed but again, I find them quite boring. What I personally like to do is go for something a little larger and a little more fun. It takes a little more time and is not as easily executed as a kata though, but it services the same purposes from a practice perspective and allows me to continue to solve some problems that are not directly part of the initial goal. This means I can cover a broader learning range and have a bit more fun. If I am lucky, sometimes they even end up being useful tools. With that in mind, I thought I’d share my current ‘kata’. It is not really a code kata as it is too big. I prefer to think of it as a ‘solution kata’. The code is on bitbucket here. What I wanted to do was create a kind of simplistic virtual world where I can create a player, or a class, stuff it into the world, and see if it survives, and can navigate its way to the exit. Requirements were pretty simple: Must be able to define a map to describe the world using simple X,Y co-ordinates. Z co-ordinates as well if you feel like getting clever. Should have the concept of entrances, exists, solid blocks, and potentially other materials (again if you want to get clever). A coder should be able to easily write a class which will act as an inhabitant of the world. An inhabitant will receive stimulus from the world in the form of surrounding environment and be able to make a decision on action which it passes back to the ‘world’ for processing. At a minimum, an inhabitant will have sight and speed characteristics which determine how far they can ‘see’ in the world, and how fast they can move. Coders who write a really bad ‘inhabitant’ should not adversely affect the rest of world. Should allow multiple inhabitants in the world. So that was the solution I set out to act as a practice solution and a little bit of fun. It had some interesting problems to solve and I figured, if it turned out ok, I could potentially use this as a ‘developer test’ for interviews. Ask a potential coder to write a class for an inhabitant. Show the coder the map they will navigate, but also mention that we will use their code to navigate a map they have not yet seen and a little more complex. I have been playing with solution for a short time now and have it working in basic concepts. Below is a screen shot using a very basic console visualiser that shows the map, boundaries, blocks, entrance, exit and players/inhabitants. The yellow asterisks ‘*’ are the players, green ‘O’ the entrance, purple ‘^’ the exit, maroon/browny ‘#’ are solid blocks. The players can move around at different speeds, knock into each others, and make directional movement decisions based on what they see and who is around them. It has been quite fun to write and it is also quite fun to develop different players to inject into the world. The code below shows a really simple implementation of an inhabitant that can work out what to do based on stimulus from the world. It is pretty simple and just tries to move in some direction if there is nothing blocking the path. public class TestPlayer:LivingEntity { public TestPlayer() { Name = "Beta Boy"; LifeKey = Guid.NewGuid(); } public override ActionResult DecideActionToPerform(EcoDev.Core.Common.Actions.ActionContext actionContext) { try { var action = new MovementAction(); // move forward if we can if (actionContext.Position.ForwardFacingPositions.Length > 0) { if (CheckAccessibilityOfMapBlock(actionContext.Position.ForwardFacingPositions[0])) { action.DirectionToMove = MovementDirection.Forward; return action; } } if (actionContext.Position.LeftFacingPositions.Length > 0) { if (CheckAccessibilityOfMapBlock(actionContext.Position.LeftFacingPositions[0])) { action.DirectionToMove = MovementDirection.Left; return action; } } if (actionContext.Position.RearFacingPositions.Length > 0) { if (CheckAccessibilityOfMapBlock(actionContext.Position.RearFacingPositions[0])) { action.DirectionToMove = MovementDirection.Back; return action; } } if (actionContext.Position.RightFacingPositions.Length > 0) { if (CheckAccessibilityOfMapBlock(actionContext.Position.RightFacingPositions[0])) { action.DirectionToMove = MovementDirection.Right; return action; } } return action; } catch (Exception ex) { World.WriteDebugInformation("Player: "+ Name, string.Format("Player Generated exception: {0}",ex.Message)); throw ex; } } private bool CheckAccessibilityOfMapBlock(MapBlock block) { if (block == null || block.Accessibility == MapBlockAccessibility.AllowEntry || block.Accessibility == MapBlockAccessibility.AllowExit || block.Accessibility == MapBlockAccessibility.AllowPotentialEntry) { return true; } return false; } } It is simple and it seems to work well. The world implementation itself decides the stimulus context that is passed to he inhabitant to make an action decision. All movement is carried out on separate threads and timed appropriately to be as fair as possible and to cater for additional skills such as speed, and eventually maybe stamina, strength, with actions like fighting. It is pretty fun to make up random maps and see how your inhabitant does. You can download the code from here. Along the way I have played with parallel extensions to make the compute intensive stuff spread across all cores, had to heavily factor in visibility of methods and properties so design of classes was paramount, work out movement algorithms that play fairly in the world and properly favour the players with higher abilities, as well as a host of other issues. So that is my ‘solution kata’. If I keep going with it, I may develop a web interface for it where people can upload assemblies and watch their player within a web browser visualiser and maybe even a map designer. What do you do to keep the fires burning?

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• SQL SERVER – Weekly Series – Memory Lane – #034

  - by Pinal Dave

  Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 UDF – User Defined Function to Strip HTML – Parse HTML – No Regular Expression The UDF used in the blog does fantastic task – it scans entire HTML text and removes all the HTML tags. It keeps only valid text data without HTML task. This is one of the quite commonly requested tasks many developers have to face everyday. De-fragmentation of Database at Operating System to Improve Performance Operating system skips MDF file while defragging the entire filesystem of the operating system. It is absolutely fine and there is no impact of the same on performance. Read the entire blog post for my conversation with our network engineers. Delay Function – WAITFOR clause – Delay Execution of Commands How do you delay execution of the commands in SQL Server – ofcourse by using WAITFOR keyword. In this blog post, I explain the same with the help of T-SQL script. Find Length of Text Field To measure the length of TEXT fields the function is DATALENGTH(textfield). Len will not work for text field. As of SQL Server 2005, developers should migrate all the text fields to VARCHAR(MAX) as that is the way forward. Retrieve Current Date Time in SQL Server CURRENT_TIMESTAMP, GETDATE(), {fn NOW()} There are three ways to retrieve the current datetime in SQL SERVER. CURRENT_TIMESTAMP, GETDATE(), {fn NOW()} Explanation and Comparison of NULLIF and ISNULL An interesting observation is NULLIF returns null if it comparison is successful, whereas ISNULL returns not null if its comparison is successful. In one way they are opposite to each other. Here is my question to you - How to create infinite loop using NULLIF and ISNULL? If this is even possible? 2008 Introduction to SERVERPROPERTY and example SERVERPROPERTY is a very interesting system function. It returns many of the system values. I use it very frequently to get different server values like Server Collation, Server Name etc. SQL Server Start Time We can use DMV to find out what is the start time of SQL Server in 2008 and later version. In this blog you can see how you can do the same. Find Current Identity of Table Many times we need to know what is the current identity of the column. I have found one of my developers using aggregated function MAX () to find the current identity. However, I prefer following DBCC command to figure out current identity. Create Check Constraint on Column Some time we just need to create a simple constraint over the table but I have noticed that developers do many different things to make table column follow rules than just creating constraint. I suggest constraint is a very useful concept and every SQL Developer should pay good attention to this subject. 2009 List Schema Name and Table Name for Database This is one of the blog post where I straight forward display script. One of the kind of blog posts, which I still love to read and write. Clustered Index on Separate Drive From Table Location A table devoid of primary key index is called heap, and here data is not arranged in a particular order, which gives rise to issues that adversely affect performance. Data must be stored in some kind of order. If we put clustered index on it then the order will be forced by that index and the data will be stored in that particular order. Understanding Table Hints with Examples Hints are options and strong suggestions specified for enforcement by the SQL Server query processor on DML statements. The hints override any execution plan the query optimizer might select for a query. 2010 Data Pages in Buffer Pool – Data Stored in Memory Cache One of my earlier year article, which I still read it many times and point developers to read it again. It is clear from the Resultset that when more than one index is used, datapages related to both or all of the indexes are stored in Memory Cache separately. TRANSACTION, DML and Schema Locks Can you create a situation where you can see Schema Lock? Well, this is a very simple question, however during the interview I notice over 50 candidates failed to come up with the scenario. In this blog post, I have demonstrated the situation where we can see the schema lock in database. 2011 Solution – Puzzle – Statistics are not updated but are Created Once In this example I have created following situation: Create Table Insert 1000 Records Check the Statistics Now insert 10 times more 10,000 indexes Check the Statistics – it will be NOT updated Auto Update Statistics and Auto Create Statistics for database is TRUE Now I have requested two things in the example 1) Why this is happening? 2) How to fix this issue? Selecting Domain from Email Address This is a straight to script blog post where I explain how to select only domain name from entire email address. Solution – Generating Zero Without using Any Numbers in T-SQL How to get zero digit without using any digit? This is indeed a very interesting question and the answer is even interesting. Try to come up with answer in next 10 minutes and if you can’t come up with the answer the blog post read this post for solution. 2012 Simple Explanation and Puzzle with SOUNDEX Function and DIFFERENCE Function In simple words - SOUNDEX converts an alphanumeric string to a four-character code to find similar-sounding words or names. DIFFERENCE function returns an integer value. The  integer returned is the number of characters in the SOUNDEX values that are the same. Read Only Files and SQL Server Management Studio (SSMS) I have come across a very interesting feature in SSMS related to “Read Only” files. I believe it is a little unknown feature as well so decided to write a blog about the same. Identifying Column Data Type of uniqueidentifier without Querying System Tables How do I know if any table has a uniqueidentifier column and what is its value without using any DMV or System Catalogues? Only information you know is the table name and you are allowed to return any kind of error if the table does not have uniqueidentifier column. Read the blog post to find the answer. Solution – User Not Able to See Any User Created Object in Tables – Security and Permissions Issue Interesting question – “When I try to connect to SQL Server, it lets me connect just fine as well let me open and explore the database. I noticed that I do not see any user created instances but when my colleague attempts to connect to the server, he is able to explore the database as well see all the user created tables and other objects. Can you help me fix it?” Importing CSV File Into Database – SQL in Sixty Seconds #018 – Video Here is interesting small 60 second video on how to import CSV file into Database. ColumnStore Index – Batch Mode vs Row Mode Here is the logic behind when Columnstore Index uses Batch Mode and when it uses Row Mode. A batch typically represents about 1000 rows of data. Batch mode processing also uses algorithms that are optimized for the multicore CPUs and increased memory throughput. Follow up – Usage of $rowguid and $IDENTITY This is an excellent follow up blog post of my earlier blog post where I explain where to use $rowguid and $identity.  If you do not know the difference between them, this is a blog with a script example. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Summit Time!

  - by Ajarn Mark Caldwell

  Boy, how time flies!  I can hardly believe that the 2011 PASS Summit is just one week away.  Maybe it snuck up on me because it’s a few weeks earlier than last year.  Whatever the cause, I am really looking forward to next week.  The PASS Summit is the largest SQL Server conference in the world and a fantastic networking opportunity thrown in for no additional charge.  Here are a few thoughts to help you maximize the week. Networking As Karen Lopez (blog | @DataChick) mentioned in her presentation for the Professional Development Virtual Chapter just a couple of weeks ago, “Don’t wait until you need a new job to start networking.”  You should always be working on your professional network.  Some people, especially technical-minded people, get confused by the term networking.  The first image that used to pop into my head was the image of some guy standing, awkwardly, off to the side of a cocktail party, trying to shmooze those around him.  That’s not what I’m talking about.  If you’re good at that sort of thing, and you can strike up a conversation with some stranger and learn all about them in 5 minutes, and walk away with your next business deal all but approved by the lawyers, then congratulations.  But if you’re not, and most of us are not, I have two suggestions for you.  First, register for Don Gabor’s 2-hour session on Tuesday at the Summit called Networking to Build Business Contacts.  Don is a master at small talk, and at teaching others, and in just those two short hours will help you with important tips about breaking the ice, remembering names, and smooth transitions into and out of conversations.  Then go put that great training to work right away at the Tuesday night Welcome Reception and meet some new people; which is really my second suggestion…just meet a few new people.  You see, “networking” is about meeting new people and being friendly without trying to “work it” to get something out of the relationship at this point.  In fact, Don will tell you that a better way to build the connection with someone is to look for some way that you can help them, not how they can help you. There are a ton of opportunities as long as you follow this one key point: Don’t stay in your hotel!  At the least, get out and go to the free events such as the Tuesday night Welcome Reception, the Wednesday night Exhibitor Reception, and the Thursday night Community Appreciation Party.  All three of these are perfect opportunities to meet other professionals with a similar job or interest as you, and you never know how that may help you out in the future.  Maybe you just meet someone to say HI to at breakfast the next day instead of eating alone.  Or maybe you cross paths several times throughout the Summit and compare notes on different sessions you attended.  And you just might make new friends that you look forward to seeing year after year at the Summit.  Who knows, it might even turn out that you have some specific experience that will help out that other person a few months’ from now when they run into the same challenge that you just overcame, or vice-versa.  But the point is, if you don’t get out and meet people, you’ll never have the chance for anything else to happen in the future. One more tip for shy attendees of the Summit…if you can’t bring yourself to strike up conversation with strangers at these events, then at the least, after you sit through a good session that helps you out, go up to the speaker and introduce yourself and thank them for taking the time and effort to put together their presentation.  Ideally, when you do this, tell them WHY it was beneficial to you (e.g. “Now I have a new idea of how to tackle a problem back at the office.”)  I know you think the speakers are all full of confidence and are always receiving a ton of accolades and applause, but you’re wrong.  Most of them will be very happy to hear first-hand that all the work they put into getting ready for their presentation is paying off for somebody. Training With over 170 technical sessions at the Summit, training is what it’s all about, and the training is fantastic!  Of course there are the big-name trainers like Paul Randall, Kimberly Tripp, Kalen Delaney, Itzik Ben-Gan and several others, but I am always impressed by the quality of the training put on by so many other “regular” members of the SQL Server community.  It is amazing how you don’t have to be a published author or otherwise recognized as an “expert” in an area in order to make a big impact on others just by sharing your personal experience and lessons learned.  I would rather hear the story of, and lessons learned from, “some guy or gal” who has actually been through an issue and came out the other side, than I would a trained professor who is speaking just from theory or an intellectual understanding of a topic. In addition to the three full days of regular sessions, there are also two days of pre-conference intensive training available.  There is an extra cost to this, but it is a fantastic opportunity.  Think about it…you’re already coming to this area for training, so why not extend your stay a little bit and get some in-depth training on a particular topic or two?  I did this for the first time last year.  I attended one day of extra training and it was well worth the time and money.  One of the best reasons for it is that I am extremely busy at home with my regular job and family, that it was hard to carve out the time to learn about the topic on my own.  It worked out so well last year that I am doubling up and doing two days or “pre-cons” this year. And then there are the DVDs.  I think these are another great option.  I used the online schedule builder to get ready and have an idea of which sessions I want to attend and when they are (much better than trying to figure this out at the last minute every day).  But the problem that I have run into (seems this happens every year) is that nearly every session block has two different sessions that I would like to attend.  And some of them have three!  ACK!  That won’t work!  What is a guy supposed to do?  Well, one option is to purchase the DVDs which are recordings of the audio and projected images from each session so you can continue to attend sessions long after the Summit is officially over.  Yes, many (possibly all) of these also get posted online and attendees can access those for no extra charge, but those are not necessarily all available as quickly as the DVD recording are, and the DVDs are often more convenient than downloading, especially if you want to share the training with someone who was not able to attend in person. Remember, I don’t make any money or get any other benefit if you buy the DVDs or from anything else that I have recommended here.  These are just my own thoughts, trying to help out based on my experiences from the 8 or so Summits I have attended.  There is nothing like the Summit.  It is an awesome experience, fantastic training, and a whole lot of fun which is just compounded if you’ll take advantage of the first part of this article and make some new friends along the way.

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• PASS: Election Changes for 2011

  - by Bill Graziano

  Last year after the election, the PASS Board created an Election Review Committee.  This group was charged with reviewing our election procedures and making suggestions to improve the process.  You can read about the formation of the group and review some of the intermediate work on the site – especially in the forums. I was one of the members of the group along with Joe Webb (Chair), Lori Edwards, Brian Kelley, Wendy Pastrick, Andy Warren and Allen White.  This group worked from October to April on our election process.  Along the way we: Interviewed interested parties including former NomCom members, Board candidates and anyone else that came forward. Held a session at the Summit to allow interested parties to discuss the issues Had numerous conference calls and worked through the various topics I can’t thank these people enough for the work they did.  They invested a tremendous number of hours thinking, talking and writing about our elections.  I’m proud to say I was a member of this group and thoroughly enjoyed working with everyone (even if I did finally get tired of all the calls.) The ERC delivered their recommendations to the PASS Board prior to our May Board meeting.  We reviewed those and made a few modifications.  I took their recommendations and rewrote them as procedures while incorporating those changes.  Their original recommendations as well as our final document are posted at the ERC documents page.  Please take a second and read them BEFORE we start the elections.  If you have any questions please post them in the forums on the ERC site. (My final document includes a change log at the end that I decided to leave in.  If you want to know which areas to pay special attention to that’s a good start.) Many of those recommendations were already posted in the forums or in the blogs of individual ERC members.  Hopefully nothing in the ERC document is too surprising. In this post I’m going to walk through some of the key changes and talk about what I remember from both ERC and Board discussions.  I’ll pay a little extra attention to things the Board changed from the ERC.  I’d also encourage any of the Board or ERC members to blog their thoughts on this. The Nominating Committee will continue to exist.  Personally, I was curious to see what the non-Board ERC members would think about the NomCom.  There was broad agreement that a group to vet candidates had value to the organization. The NomCom will be composed of five members.  Two will be Board members and three will be from the membership at large.  The only requirement for the three community members is that you’ve volunteered in some way (and volunteering is defined very broadly).  We expect potential at-large NomCom members to participate in a forum on the PASS site to answer questions from the other PASS members. We’re going to hold an election to determine the three community members.  It will be closer to voting for Summit sessions than voting for Board members.  That means there won’t be multiple dedicated emails.  If you’re at all paying attention it will be easy to participate.  Personally I wanted it easy for those that cared to participate but not overwhelm those that didn’t care.  I think this strikes a good balance. There’s also a clause that in order to be considered a winner in this NomCom election, you must receive 10 votes.  This is something I suggested.  I have no idea how popular the NomCom election is going to be.  I just wanted a fallback that if no one participated and some random person got in with one or two votes.  Any open slots will be filled by the NomCom chair (usually the PASS Immediate Past President).  My assumption is that they would probably take the next highest vote getters unless they were throwing flames in the forums or clearly unqualified.  As a final check, the Board still approves the final NomCom. The NomCom is going to rank candidates instead of rating them.  This has interesting implications.  This was championed by another ERC member and I’m hoping they write something about it.  This will really force the NomCom to make decisions between candidates.  You can’t just rate everyone a 3 and be done with it.  It may also make candidates appear further apart than they actually are.  I’m looking forward talking with the NomCom after this election and getting their feedback on this. The PASS Board added an option to remove a candidate with a unanimous vote of the NomCom.  This was primarily put in place to handle people that lied on their application or had a criminal background or some other unusual situation and we figured it out. We list an explicit goal of three candidate per open slot. We also wanted an easy way to find the NomCom candidate rankings from the ballot.  Hopefully this will satisfy those that want a broad candidate pool and those that want the NomCom to identify the most qualified candidates. The primary spokesperson for the NomCom is the committee chair.  After the issues around the election last year we didn’t have a good communication plan in place.  We should have and that was a failure on the part of the Board.  If there is criticism of the election this year I hope that falls squarely on the Board.  The community members of the NomCom shouldn’t be fielding complaints over the election process.  That said, the NomCom is ranking candidates and we are forcing them to rank some lower than others.  I’m sure you’ll each find someone that you think should have been ranked differently.  I also want to highlight one other change to the process that we started last year and isn’t included in these documents.  I think the candidate forums on the PASS site were tremendously helpful last year in helping people to find out more about candidates.  That gives our members a way to ask hard questions of the candidates and publicly see their answers. This year we have two important groups to fill.  The first is the NomCom.  We need three people from our membership to step up and fill this role.  It won’t be easy.  You will have to make subjective rankings of your fellow community members.  Your actions will be important in deciding who the future leaders of PASS will be.  There’s a 50/50 chance that one of the people you interview will be the President of PASS someday.  This is not a responsibility to be taken lightly. The second is the slate of candidates.  If you’ve ever thought about running for the Board this is the year.  We’ve never had nine candidates on the ballot before.  Your chance of making it through the NomCom are higher than in any previous year.  Unfortunately the more of you that run, the more of you that will lose in the election.  And hopefully that competition will mean more community involvement and better Board members for PASS. Is this the end of changes to the election process?  It isn’t.  Every year that I’ve been on the Board the election process has changed.  Some years there have been small changes and some years there have been large changes.  After this election we’ll look at how the process worked and decide what steps to take – just like we do every year.

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