Search Results

Search found 5101 results on 205 pages for 'expression trees'.

Page 176/205 | < Previous Page | 172 173 174 175 176 177 178 179 180 181 182 183  | Next Page >

• Why do people hate SQL cursors so much?

  - by Steven A. Lowe

  I can understand wanting to avoid having to use a cursor due to the overhead and inconvenience, but it looks like there's some serious cursor-phobia-mania going on where people are going to great lengths to avoid having to use one for example, one question asked how to do something obviously trivial with a cursor and the accepted answer proposed using a common table expression (CTE) recursive query with a recursive custom function, even though this limits the number of rows that could be processed to 32 (due to recursive call limit in sql server). This strikes me as a terrible solution for system longevity, not to mention a tremendous effort just to avoid using a simple cursor. what is the reason for this level of insane hatred? has some 'noted authority' issued a fatwa against cursors? does some unspeakable evil lurk in the heart of cursors that corrupts the morals of the children or something? wiki question, more interested in the answer than the rep thanks in advance! Related Info: http://stackoverflow.com/questions/37029/sql-server-fast-forward-cursors EDIT: let me be more precise: I understand that cursors should not be used instead of normal relational operations, that is a no-brainer. What I don't understand is people going waaaaay out of their way to avoid cursors like they have cooties or something, even when a cursor is a simpler and/or more efficient solution. It's the irrational hatred that baffles me, not the obvious technical efficiencies.

  Read the article

• Why are all objects in this extension of usercontrol null at runtime?

  - by csciguy

  All, I have a simple class. public class Container : UserControl { public bool IsClickable { get; set; } } I have a class that extends this class. public class ScrollingContainer : Container { public void Draw() { } public void Update() { } } I have a custom class, that then extends ScrollingContainer. public partial class MaskContainer : ScrollingContainer { public MaskContainer() { InitializeComponent(); } } XAML <local:ScrollingContainer x:Class="Test.Types.MaskContainer" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:local="clr-namespace:GameObjects;assembly=GameObjects" mc:Ignorable="d" > </local:ScrollingContainer> In my mainpage.xaml, I have the following. <types:MaskContainer x:Name="maskContainer" Canvas.ZIndex="1" Width="Auto" Height="Auto"> <Canvas x:Name="maskCanvas"> <Button x:Name="button1" Content="test button"/> </Canvas> </types:MaskContainer> Why, at runtime, are both maskCanvas and button1 null? maskContainer is not null. The inheritance should be straightforward here. Container inherits usercontrol. Scrollable container inherits container. Mask Container inherits scrollable container. Why am I losing the fucntionality of the original base class at this level? Is it incorrect to add the element (button1) to the maskcontainer inside of the main.xaml? My end goal is to create a container that is reusable, but inherits all properties/methods that I've specified throughout the chain. Any help is appreciated.

  Read the article

• Python: puzzling behaviour inside httplib

  - by Anna

  I have added one line ( import pdb; pdb.set_trace() ) to httplib's HTTPConnection.putheader, so I can see what's going on inside. httplib.py, line 489: def putheader(self, header, value): """Send a request header line to the server. For example: h.putheader('Accept', 'text/html') """ import pdb; pdb.set_trace() if self.__state != _CS_REQ_STARTED: raise CannotSendHeader() str = '%s: %s' % (header, value) self._output(str) then ran this from the interpreter import urllib2 urllib2.urlopen('http://www.ioerror.us/ip/headers') ... and as expected PDB kicks in: > c:\python26\lib\httplib.py(858)putheader() -> if self.__state != _CS_REQ_STARTED: (Pdb) in PDB I have the luxury of evaluating expressions on the fly, so I have tried to enter self.__state: (Pdb) self.__state *** AttributeError: HTTPConnection instance has no attribute '__state' Alas, there is no __state of this instance. However when I enter step, the debugger gets past the if self.__state != _CS_REQ_STARTED: line without a problem. Why is this happening? If the self.__state doesn't exist python would have to raise an exception as it did when I entered the expression. Python version: 2.6.4 on win32

  Read the article

• How to add an image to an SSRS report with a dynamic url?

  - by jrummell

  I'm trying to add an image to a report. The image src url is an IHttpHandler that takes a few query string parameters. Here's an example: <img src="Image.ashx?item=1234567890&lot=asdf&width=50" alt=""/> I added an Image to a cell and then set Source to External and Value to the following expression: ="Image.ashx?item="+Fields!ItemID.Value+"&lot="+Fields!LotID.Value+"&width=50" But when I view the report, it renders the image html as: <IMG SRC="" /> What am I missing? Update Even if I set Value to "image.jpg" it still renders an empty src attribute. I'm not sure if it makes a difference, but I'm using this with a VS 2008 ReportViewer control in Remote processing mode. Update I was able to get the images to display in the Report Designer (VS 2005) with an absolute path (http://server/path/to/http/handler). But they didn't display on the Report Manager website. I even set up an Unattended Execution Account that has access to the external URLs.

  Read the article

• Variable field in a constraint annotation

  - by Javi

  Hello, I need to create a custom constraint annotation which can access the value of another field of my bean. I'll use this annotation to validate the field because it depends on the value of the other but the way I define it the compiler says "The value for annotation attribute" of my field "must be a constant expression". I've defined it in this way: @Target(ElementType.FIELD) @Retention(RetentionPolicy.RUNTIME) @Constraint(validatedBy=EqualsFieldValidator.class) @Documented public @interface EqualsField { public String field(); String message() default "{com.myCom.annotations.EqualsField.message}"; Class<?>[] groups() default {}; Class<? extends Payload>[] payload() default {}; } public class EqualsFieldValidator implements ConstraintValidator<EqualsField, String>{ private EqualsField equalsField; @Override public void initialize(EqualsField equalsField) { this.equalsField = equalsField; } @Override public boolean isValid(String thisField, ConstraintValidatorContext arg1) { //my validation } } and in my bean I want something like this: public class MyBean{ private String field1; @EqualsField(field=field1) private String field2; } Is there any way to define the annotation so the field value can be a variable? Thanks

  Read the article

• How do I select the last XHTML <span> element with a particular class in XPath?

  - by Fintan

  My target XHTML document (simplified) is like the following: <html> <head> </head> <body> <span class="boris"> </span> <span class="boris"> </span> <span class="johnson"> </span> </body> </html> I'm trying to select the last of class "boris." The XPath expression //span[@class="boris"] selects all spans of class boris. How do I select the last one of these? I've tried //span[@class="boris" and last()] which doesn't work because last() here refers to the last span in the WHOLE DOCUMENT. How do I select all the spans of class boris... and then the last one of these? I've read 5 or 6 XPath tutorials and done a lot of Googling and I can't find a way to do this in XPath alone :( Thanks in advance for help :)

  Read the article

• Parsing files "/etc/default" using java

  - by rmarimon

  I'm trying to parse the configuration files usually found in /etc/default using java and regular expressions. So far this is the code I have iterating over every line on each file: // remove comments from the line int hash = line.indexOf("#"); if (hash >= 0) { line = line.substring(0, hash); } // create the patterns Pattern doubleQuotePattern = Pattern.compile("\\s*([a-zA-Z_][a-zA-Z_0-9]*)\\s*=\\s*\"(.*)\"\\s*"); Pattern singleQuotePattern = Pattern.compile("\\s*([a-zA-Z_][a-zA-Z_0-9]*)\\s*=\\s*\\'(.*)\\'\\s*"); Pattern noQuotePattern = Pattern.compile("\\s*([a-zA-Z_][a-zA-Z_0-9]*)\\s*=(.*)"); // try to match each of the patterns to the line Matcher matcher = doubleQuotePattern.matcher(line); if (matcher.matches()) { System.out.println(matcher.group(1) + " == " + matcher.group(2)); } else { matcher = singleQuotePattern.matcher(line); if (matcher.matches()) { System.out.println(matcher.group(1) + " == " + matcher.group(2)); } else { matcher = noQuotePattern.matcher(line); if (matcher.matches()) { System.out.println(matcher.group(1) + " == " + matcher.group(2)); } } } This works as I expect but I'm pretty sure that I can make this way smaller by using better regular expression but I haven't had any luck. Anyone know of a better way to read these types of files?

  Read the article

• "<" operator error

  - by Nona Urbiz

  Why is the ( i < UniqueWords.Count ) expression valid in the for loop, but returns "CS0019 Operator '<' cannot be applied to operands of type 'int' and 'method group'" error when placed in my if? They are both string arrays, previously declared. for (int i = 0;i<UniqueWords.Count;i++){ Occurrences[i] = Words.Where(x => x.Equals(UniqueWords[i])).Count(); Keywords[i] = UniqueWords[i]; if (i<UniqueURLs.Count) {rURLs[i] = UniqueURLs[i];} } EDITED to add declarations: List<string> Words = new List<string>(); List<string> URLs = new List<string>(); //elements added like so. . . . Words.Add (referringWords); //these are strings URLs.Add (referringURL); UniqueWords = Words.Distinct().ToList(); UniqueURLs = URLs.Distinct().ToList(); SOLVED. thank you, parentheses were needed for method .Count() I still do not fully understand why they are not always necessary. Jon Skeet, thanks, I guess I don't understand what exactly the declarations are either then? You wanted the actual values assigned? They are pulled from an external source, but are strings. I get it! Thanks. (the ()'s at least.)

  Read the article

• Issue with getting 2 chars from string using indexer

  - by Learner

  I am facing an issue in reading char values. See my program below. I want to evaluate an infix expression. As you can see I want to read '10' , '*', '20' and then use them...but if I use string indexer s[0] will be '1' and not '10' and hence I am not able to get the expected result. Can you guys suggest me something? Code is in c# class Program { static void Main(string[] args) { string infix = "10*2+20-20+3"; float result = EvaluateInfix(infix); Console.WriteLine(result); Console.ReadKey(); } public static float EvaluateInfix(string s) { Stack<float> operand = new Stack<float>(); Stack<char> operator1 = new Stack<char>(); int len = s.Length; for (int i = 0; i < len; i++) { if (isOperator(s[i])) // I am having an issue here as s[i] gives each character and I want the number 10 operator1.Push(s[i]); else { operand.Push(s[i]); if (operand.Count == 2) Compute(operand, operator1); } } return operand.Pop(); } public static void Compute(Stack<float> operand, Stack<char> operator1) { float operand1 = operand.Pop(); float operand2 = operand.Pop(); char op = operator1.Pop(); if (op == '+') operand.Push(operand1 + operand2); else if(op=='-') operand.Push(operand1 - operand2); else if(op=='*') operand.Push(operand1 * operand2); else if(op=='/') operand.Push(operand1 / operand2); } public static bool isOperator(char c) { bool result = false; if (c == '+' || c == '-' || c == '*' || c == '/') result = true; return result; } } }

  Read the article

• Workaround for basic syntax not being parsed.

  - by Mark Tomlin

  I want to have a class property that allow for an expression to take place on the right side of the equals sign. All versions of PHP choke on the following code, but it is written in this way to allow for easier extendibility in the future. /* Example SDK Class */ class SDK { /* Runtime Option Flags */ // Strings # 0: Makes no change to the strings. var $STRING_NONE = (1 << 0); # 1: Removes color codes from the string. var $STRING_STRIP_COLOR = (1 << 1); # 2: Removes language codes from the string. var $STRING_STRIP_LANG = (1 << 2); # 3: Removes all formatting from the string. var $STRING_STRIP = SELF::STRING_STRIP_COLOR & SELF::STRING_STRIP_LANG; # 4: Converts color codes to HTML & UTF-8. var $STRING_HTML = (1 << 3); # 8: Converts color codes to ECMA-48 escape color codes & UTF-8. var $STRING_CONSOLE = (1 << 4); # 16: Changes player names only. var $STRING_NAMES = (1 << 5); # 32: Changes host names only. var $STRING_HOSTS = (1 << 6); function SDK($fString = SELF::STRING_HTML & SELF::STRING_NAMES & SELF_HOST) { // constructor code. } } $SDK &= new SDK(SDK::STRING_NONE); (1 << 0) seems like very basic syntax to me, and is not fathomable why PHP would not allow for such a thing. Can anyone think of a work around that would maintain readability and future expandability of the following code?

  Read the article

• Are lambda expressions/delegates in C# "pure", or can they be?

  - by Bob

  I recently asked about functional programs having no side effects, and learned what this means for making parallelized tasks trivial. Specifically, that "pure" functions make this trivial as they have no side effects. I've also recently been looking into LINQ and lambda expressions as I've run across examples many times here on StackOverflow involving enumeration. That got me to wondering if parallelizing an enumeration or loop can be "easier" in C# now. Are lambda expressions "pure" enough to pull off trivial parallelizing? Maybe it depends on what you're doing with the expression, but can they be pure enough? Would something like this be theoretically possible/trivial in C#?: Break the loop into chunks Run a thread to loop through each chunk Run a function that does something with the value from the current loop position of each thread For instance, say I had a bunch of objects in a game loop (as I am developing a game and was thinking about the possibility of multiple threads) and had to do something with each of them every frame, would the above be trivial to pull off? Looking at IEnumerable it seems it only keeps track of the current position, so I'm not sure I could use the normal generic collections to break the enumeration into "chunks". Sorry about this question. I used bullets above instead of pseudo-code because I don't even know enough to write pseudo-code off the top of my head. My .NET knowledge has been purely simple business stuff and I'm new to delegates and threads, etc. I mainly want to know if the above approach is good for pursuing, and if delegates/lambdas don't have to be worried about when it comes to their parallelization.

  Read the article

• compact Number formatting behavior in Java (automatically switch between decimal and scientific notation)

  - by kostmo

  I am looking for a way to format a floating point number dynamically in either standard decimal format or scientific notation, depending on the value of the number. For moderate magnitudes, the number should be formatted as a decimal with trailing zeros suppressed. If the floating point number is equal to an integral value, the decimal point should also be suppressed. For extreme magnitudes (very small or very large), the number should be expressed in scientific notation. Alternately stated, if the number of characters in the expression as standard decimal notation exceeds a certain threshold, switch to scientific notation. I should have control over the maximum number of digits of precision, but I don't want trailing zeros appended to express the minimum precision; all trailing zeros should be suppressed. Basically, it should optimize for compactness and readability. 2.80000 - 2.8 765.000000 - 765 0.0073943162953 - 0.00739432 (limit digits of precision—to 6 in this case) 0.0000073943162953 - 7.39432E-6 (switch to scientific notation if the magnitude is small enough—less than 1E-5 in this case) 7394316295300000 - 7.39432E+6 (switch to scientific notation if the magnitude is large enough—for example, when greater than 1E+10) 0.0000073900000000 - 7.39E-6 (strip trailing zeros from significand in scientific notation) 0.000007299998344 - 7.3E-6 (rounding from the 6-digit precision limit causes this number to have trailing zeros which are stripped) Here's what I've found so far: The .toString() method of the Number class does most of what I want, except it doesn't upconvert to integer representation when possible, and it will not express large integral magnitudes in scientific notation. Also, I'm not sure how to adjust the precision. The "%G" format string to the String.format(...) function allows me to express numbers in scientific notation with adjustable precision, but does not strip trailing zeros. I'm wondering if there's already some library function out there that meets these criteria. I guess the only stumbling block for writing this myself is having to strip the trailing zeros from the significand in scientific notation produced by %G.

  Read the article

• Problem with .Contains

  - by Rene

  Hello there, I have a little problem which i can't solve. I want to use an SQL-In-Statement in Linq. I've read in this Forum and in other Forums that I have to use the .Contains (with reverse-thinking-notation :-)). As input i have a List of Guids. I first copied them into an array and then did something like that : datatoget = (from p in objectContext.MyDataSet where ArrayToSearch.Contains(p.Subtable.Id.ToString()) select p).ToList(); datatoget is the result in which all records matching the Subtable.Id (which is a Guid) should be stored. Subtable is a Detail-Table from MyData, and the Id is a Guid-Type. I've tried several things (Convert Guid to String, and then using .Contains, etc), but I always get an Exception which says : 'Linq to Entities' doesn't recognize the Method 'Boolean Contains(System.Guid) and is not able to Translate this method into a memory expression. (Something like that, because I'm using the German Version of VS2008) I am using L2E with .NET 3.5 and am programming in C# with VS 2008. I've read several Examples, but it doesn't work. Is it perhaps because of using Guid's instead of strings ? I've also tried to write my own compare-function, but I don't know how to integrate it so that .NET calls my function for comparing.

  Read the article

• Creating a DataTable by filtering another DataTable

  - by Jeff Dege

  I'm working on a system that currently has a fairly complicated function that returns a DataTable, which it then binds to a GUI control on a ASP.NET WebForm. My problem is that I need to filter the data returned - some of the data that is being returned should not be displayed to the user. I'm aware of DataTable.select(), but that's not really what I need. First, it returns an array of DataRows, and I need a DataTable, so I can databind it to the GUI control. But more importantly, the filtering I need to do isn't something that can be easily put into a simple expression. I have an array of the elements which I do not want displayed, and I need to compare each element from the DataTable against that array. What I could do, of course, is to create a new DataTable, reading everything out of the original, adding to the new what is appropriate, then databinding the new to the GUI control. But that just seems wrong, somehow. In this case, the number of elements in the original DataTable aren't likely to be enough that copying them all in memory is going to cause too much trouble, but I'm wondering if there is another way. Does the .NET DataTable have functionality that would allow me to filter via a callback function?

  Read the article

• adding multiple <asp:Hyperlink>s into a repeater

  - by Colin Pickard

  I have a repeater control, and I want to put an unknown number of <asp:Hyperlink>s into the template, for example if you start with this: <asp:Repeater runat="server" ID="PetsRepeater"> <ItemTemplate> <%#DataBinder.Eval(Container.DataItem, "Owner")%> <%#this.ListPets(Container.DataItem)%> </ItemTemplate> </asp:Repeater> and in code behind: public partial class test1 : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { PetOwner p = new PetOwner() { Owner = "Jimmy", PetNames = new List<String>() { "Nemo", "Dory" } }; List<PetOwner> PetOwners = new List<PetOwner>() { p }; PetsRepeater.DataSource = PetOwners; PetsRepeater.DataBind(); } } protected String ListPets(Object PetOwner) { StringBuilder sb = new StringBuilder(); foreach (String Name in ((PetOwner)PetOwner).PetNames) { if (sb.Length > 0) sb.Append(", "); sb.Append(Name); } return sb.ToString(); } } class PetOwner { public String Owner; public List<String> PetNames; } Now suppose instead of having the string "Nemo, Dory" in my repeater, I want something like this: <asp:HyperLink runat=server Text="Nemo" NavigateUrl="Pet.aspx?Name=Nemo" />, <asp:HyperLink runat=server Text="Dory" NavigateUrl="Pet.aspx?Name=Dory" /> How can I do that? I tried putting a foreach inline in the aspx page, but I get the error Invalid expression term 'foreach'.

  Read the article

• jQuery RJS inserting string vs dom.

  - by Dmitriy Likhten

  So I am trying to use jQuery to insert data from an ajax call. I actually use the jquery.form plugin, and have the ajax form submitted with a dataType: 'script'. The response is a jquery expression which contains a <%= javascript_escape(render ...) %> erb tag (similar to what the railscasts episode 136 instructs to do). However the end result is that the full text of the render is inserted as if that was the content to be inserted into the page, as text, not as dom elements. Could the fact that the render had some newlines at the beginning be the cause? Dom text: "\n \n &lt;li>....&lt;/li>" I also tried having jQuery just read the response as a script and execute it, and used the prototype-based rjs stuff, same effect, the text is inserted into the dom. Are there any reasons why such a behavior would be experienced? A bit of clarification: My response.js.erb is jQuery("#content").append("<%= escape_javascript(render(:partial => "widgets")) %>"); jQuery("#information").text("Finally, something happened!"); The full text inside the append() call is inserted as text into #content.

  Read the article

• Selectively replacing words outside of tags using regular expressions in PHP?

  - by Gary Willoughby

  I have a paragraph of text and i want to replace some words using PHP (preg_replace). Here's a sample piece of text: This lesson addresses rhyming [one]words and ways[/one] that students may learn to identify these words. Topics include learning that rhyming words sound alike and these sounds all come from the [two]ending of the words[/two]. This can be accomplished by having students repeat sets of rhyming words so that they can say them and hear them. The students will also participate in a variety of rhyming word activities. In order to demonstrate mastery the students will listen to [three]sets of words[/three] and tell the teacher if the words rhyme or not. If you notice there are many occurances of the word 'words'. I want to replace all the occurances that don't occur inside any of the tags with the word 'birds'. So it looks like this: This lesson addresses rhyming [one]words and ways[/one] that students may learn to identify these birds. Topics include learning that rhyming birds sound alike and these sounds all come from the [two]ending of the words[/two]. This can be accomplished by having students repeat sets of rhyming birds so that they can say them and hear them. The students will also participate in a variety of rhyming word activities. In order to demonstrate mastery the students will listen to [three]sets of words[/three] and tell the teacher if the birds rhyme or not. Would you use regular expressions to accomplish this? Can a regular expression accomplish this?

  Read the article

• Extending EF4 SQL Generation

  - by Basiclife

  Hi, We're using EF4 in a fairly large system and occasionally run into problems due to EF4 being unable to convert certain expressions into SQL. At present, we either need to do some fancy footwork (DB/Code) or just accept the performance hit and allow the query to be executed in-memory. Needless to say neither of these is ideal and the hacks we've sometimes had to use reduce readability / maintainability. What we would ideally like is a way to extend the SQL generation capabilities of the EF4 SQL provider. Obviously there are some things like .Net method calls which will always have to be client-side but some functionality like date comparisons (eg Group by weeks in Linq to Entities ) should be do-able. I've Googled but perhaps I'm using the wrong terminology as all I get is information about the new features of EF4 SQL Generation. For such a flexible and extensible framework, I'd be surprised if this isn't possible. In my head, I'm imagining inheriting from the [SQL 2008] provider and extending it to handle additional expressions / similar in the expression tree it's given to convert to SQL. Any help/pointers appreciated. We're using VS2010 Ultimate, .Net 4 (non-client profile) and EF4. The app is in ASP.Net and is running in a 64-Bit environment in case it makes a difference.

  Read the article

• PHP-REGEX: accented letters matches non-accented ones, and visceversa. How to achive it?

  - by Lightworker

  I want to do the typical higlight code. So I have something like: $valor = preg_replace("/(".$_REQUEST['txt_search'].")/iu", "<span style='background-color:yellow; font-weight:bold;'>\\1</span>", $valor); Now, the request word could be something like "josé". And with it, I want "jose" or "JOSÉ" or "José" or ... highlighted too. With this expression, if I write "josé", it matches "josé" and "JOSÉ" (and all the case variants). It always matches the accented variants only. If I search "jose", it matches "JOSE", "jose", "Jose"... but not the accented ones. So I've partially what I want, cause I have case insensitive on accented and non-accented separately. I need it fully combined, wich means accent (unicode) insensitive, so I can search "jose", and highlight "josé", "josÉ", "José", "JOSE", "JOSÉ", "JoSé", ... I don't want to do a replace of accents on the word, cause when I print it on screen I need to see the real word as it comes. Any ideas? Thanks!

  Read the article

• UITabBarControllerDelegate compare value of viewController

  - by T9

  I have a tabBar with 4 tabs on it, and I want to perform some action when a specific tab is selected, so I have uncommented the UITabBarControllerDelegate in the xxAppDelegate.m I also wanted to see the value that was being sent logged in the console - in order to test my "if" statement. However this is where I got stumped. // Optional UITabBarControllerDelegate method - (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController { NSLog(@"%@", viewController); } The console dutifully logged any selected controller that had been selected, but in this particular format: <MyViewController: 0x3b12950> Now, I wasn't expecting the square brackets or the colon or the Hex. So my question is how do I format my IF statement? This is what I thought would work but I get an error mentioned further down. // Optional UITabBarControllerDelegate method - (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController { NSLog(@"%@", viewController); if (viewController == MyViewController) { //do something nice here … }; } ... The error is "Expected expression before 'MyViewController'" Anyone know how I should be doing this?

  Read the article

• How to render a DateTime in a specific format in ASP.NET MVC 3?

  - by Slauma

  If I have in my model class a property of type DateTime how can I render it in a specific format - for example in the format which ToLongDateString() returns? I have tried this... @Html.DisplayFor(modelItem => item.MyDateTime.ToLongDateString()) ...which throws an exception because the expression must point to a property or field. And this... @{var val = item.MyDateTime.ToLongDateString(); Html.DisplayFor(modelItem => val); } ...which doesn't throw an exception, but the rendered output is empty (although val contains the expected value, as I could see in the debugger). Thanks for tips in advance! Edit ToLongDateString is only an example. What I actually want to use instead of ToLongDateString is a custom extension method of DateTime and DateTime?: public static string FormatDateTimeHideMidNight(this DateTime dateTime) { if (dateTime.TimeOfDay == TimeSpan.Zero) return dateTime.ToString("d"); else return dateTime.ToString("g"); } public static string FormatDateTimeHideMidNight(this DateTime? dateTime) { if (dateTime.HasValue) return dateTime.Value.FormatDateTimeHideMidNight(); else return ""; } So, I think I cannot use the DisplayFormat attribute and DataFormatString parameter on the ViewModel properties.

  Read the article

• Bash and regex problem : check for tokens entered into a Coke vending machine

  - by Michael Mao

  Hi all: Here is a "challenge question" I've got from Linux system programming lecture. Any of the following strings will give you a Coke if you kick: L = { aaaa, aab, aba, baa, bb, aaaa"a", aaaa"b", aab"a", … ab"b"a, ba"b"a, ab"bbbbbb"a, ... } The letters shown in wrapped double quotes indicate coins that would have fallen through (but those strings are still part of the language in this example). Exercise (a bit hard) show this is the language of a regular expression And this is what I've got so far : #!/usr/bin/bash echo "A bottle of Coke costs you 40 cents" echo -e "Please enter tokens (a = 10 cents, b = 20 cents) in a sequence like 'abba' :\c" read tokens #if [ $tokens = aaaa ]||[ $tokens = aab ]||[ $tokens = bb ] #then # echo "Good! now a coke is yours!" #else echo "Thanks for your money, byebye!" if [[ $token =~ 'aaaa|aab|bb' ]] then echo "Good! now a coke is yours!" else echo "Thanks for your money, byebye!" fi Sadly it doesn't work... always outputs "Thanks for your money, byebye!" I believe something is wrong with syntax... We didn't provided with any good reference book and the only instruction from the professor was to consult "anything you find useful online" and "research the problem yourself" :( I know how could I do it in any programming language such as Java, but get it done with bash script + regex seems not "a bit hard" but in fact "too hard" for anyone with little knowledge on something advanced as "lookahead"(is this the terminology ?) I don't know if there is a way to express the following concept in the language of regex: Valid entry would consist of exactly one of the three components : aaaa, aab and bb, regardless of order, followed by an arbitrary sequence of a or b's So this is what is should be like : (a{4}Ua{2}bUb{2})(aUb)* where the content in first braces is order irrelevant. Thanks a lot in advance for any hints and/or tips :)

  Read the article

• Best approach, Dynamic OpenXML in T-SQL

  - by Martin Ongtangco

  hello, i'm storing XML values to an entry in my database. Originally, i extract the xml datatype to my business logic then fill the XML data into a DataSet. I want to improve this process by loading the XML right into the T-SQL. Instead of getting the xml as string then converting it on the BL. My issue is this: each xml entry is dynamic, meaning it can be any column created by the user. I tried using this approach, but it's giving me an error: CREATE PROCEDURE spXMLtoDataSet @id uniqueidentifier, @columns varchar(max) AS BEGIN -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SET NOCOUNT ON; DECLARE @name varchar(300); DECLARE @i int; DECLARE @xmlData xml; (SELECT @xmlData = data, @name = name FROM XmlTABLES WHERE (tableID = ISNULL(@id, tableID))); EXEC sp_xml_preparedocument @i OUTPUT, @xmlData DECLARE @tag varchar(1000); SET @tag = '/NewDataSet/' + @name; DECLARE @statement varchar(max) SET @statement = 'SELECT * FROM OpenXML(@i, @tag, 2) WITH (' + @columns + ')'; EXEC (@statement); EXEC sp_xml_removedocument @i END where i pass a dynamically written @columns. For example: spXMLtoDataSet 'bda32dd7-0439-4f97-bc96-50cdacbb1518', 'ID int, TypeOfAccident int, Major bit, Number_of_Persons int, Notes varchar(max)' but it kept on throwing me this exception: Msg 137, Level 15, State 2, Line 1 Must declare the scalar variable "@i". Msg 319, Level 15, State 1, Line 1 Incorrect syntax near the keyword 'with'. If this statement is a common table expression or an xmlnamespaces clause, the previous statement must be terminated with a semicolon.

  Read the article

• Getting the first result from a LINQ query - why does ElementAt<T>(0) fails when First<T>() succeeds

  - by Mr Roys

  I have a method AddStudent() which looks for a student with the same name and returns an existing student from the database if there is a student with the same name, otherwise it creates a new student and adds it to the database. I'm curious why se = students.First<StudentEntity>(); succeeds when se = students.ElementAt<StudentEntity>(0); fails when I try to get the first result from the LINQ query. Aren't the two methods the same? The full code for the method is shown below. public Student AddStudent(string name) { using (SchoolEntities db = new SchoolEntities()) { // find student with same name via LINQ var students = from s in db.StudentEntitySet where s.name == name select s; StudentEntity se = default(StudentEntity); // if student with the same name is already present, return // that student if (students.Count<StudentEntity>() > 0) { // if i use ElementAt, if fails with a "LINQ to Entities does not // recognize the method 'StudentEntity ElementAt[StudentEntity] // (System.Linq.IQueryable`1[StudentEntity], Int32)' method, // and this method cannot be translated into a store expression.", // but not when I use First. Why? // se = students.ElementAt<StudentEntity>(0); se = students.First<StudentEntity>(); } else { // passing 0 for first parameter (id) since it's represented by // a BigInt IDENTITY field in the database so any value // doesn't matter. se = StudentEntity.CreateStudentEntity(0, name); db.AddToStudentEntitySet(se); db.SaveChanges(); } // create a Student object from the Entity object return new Student(se); } } Thanks!

  Read the article

• How do you localize/internationalize an MVC Controller when using a SQL based localization provider?

  - by EBarr

  Hopefully this isn't too silly of a question. In MVC there appears to be plenty of localization support in the views. Once I get to the controller, however, it becomes murky. Using meta:resourcekey="blah" is out, same with <%$ Resources:PageTitle.Text%. ASP.NET MVC - Localization Helpers -- suggested extensions for the Html helper classes like Resource(this Controller controller, string expression, params object[] args). Similarly, Localize your MVC with ease suggested a slightly different extension like Localize(this System.Web.UI.UserControl control, string resourceKey, params object[] args) None of these approaches works while in a controller. I put together the below function and I'm using the controllers full class name as my VirtualPath. But I'm new to MVC and assume there's a better way. public static string Localize (System.Type theType, string resourceKey, params object[] args) { string resource = (HttpContext.GetLocalResourceObject(theType.FullName, resourceKey) ?? string.Empty).ToString(); return mergeTokens(resource, args); } Thoughts? Comments?

  Read the article

< Previous Page | 172 173 174 175 176 177 178 179 180 181 182 183  | Next Page >