Search Results

Search found 14283 results on 572 pages for 'django generic views'.

Page 487/572 | < Previous Page | 483 484 485 486 487 488 489 490 491 492 493 494  | Next Page >

  • Extension methods in class library project

    - by Mostafa
    I've implemented some extension methods and put those in separate Class Library project. Imagine I have a simple extension method like this in class library called MD.Utility: namespace MD.Utility { public static class ExtenMethods { public static bool IsValidEmailAddress(this string s) { Regex regex = new Regex(@"^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$"); return regex.IsMatch(s); } } } But nowhere in WebApp like App_code folder or WebFroms code-behind page I can't use this Extension method. If I do like this: using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using MD.Utility; public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { string email = "[email protected]"; if (email.IsValidEmailAddress()) { //To do } } } The compiler doesn't recognize IsValidEmailAddress() and even no intellisense support. While if I put my extension method in App_Code folder it's ok for using in another cs file in App_code Folder or Web Form code-behind pages.

    Read the article

  • CAShapeLayer slowing down interface rotation

    - by MrMage
    Hi, I am trying to move some custom drawing code from a view into a CAShapeLayer, which then get added as a sublayer to the original view's CALayer. This also works well, but when rotating the device, the animation starts to stutter, e.g. you just see the frame in the original orientation and then the final orientation, with at most one frame in between - not smooth at all. Slide-in and slide-out animations of the corresponding UIViewController are a bit jerky, too (but not that much). All the CAShapeLayer has in its path is one CGPathAddRect, it is set to be opaque, its opacity is 1.0f and the fillColor is set to opaque blue. When drawing the path directly in the views drawRect method, however, the animation is smooth. So I suppose it has something to do with the CAShapeLayer being animated during the rotation. Could you tell me how to either get rid of those jerkiness or just hide the CAShapeLayer when animating? Getting back to just draw CGPaths directly is not an option to me because I rely on the ability of CAShapeLayer to animate its path (it is not animated in my tries with rotating the view). /update: this also happens when the rotating UIViewControllers view contains a view with a subclass of CAGradientLayer as its layerClass (e.g. a view with a gradient layer as background). Cheers MrMage

    Read the article

  • Multiple user roles in Ruby on Rails

    - by aguynamedloren
    I am building an inventory management application with four different user types: admin, employee, manufacturer, transporter. I haven't started coding yet, but this is what I'm thinking.. Manufacturers and transporters are related with has_many :through many-to-many association with products as follows: class Manufacturer < ActiveRecord::Base has_many :products has_many :transporters, :through => :products end class Product < ActiveRecord::Base belongs_to :manufacturer belongs_to :transporter end class Transporter < ActiveRecord::Base has_many :products has_many :manufacturers, :through => :products end All four user types will be able to login, but they will have different permissions and views, etc. I don't think I can put them in the same table (Users), however, because they will have different requirements, ie: vendors and manufacturers must have a billing address and contact info (through validations), but admins and employees should not have these fields. If possible, I would like to have a single login screen as opposed to 4 different screens. I'm not asking for the exact code to build this, but I'm having trouble determining the best way to make it happen. Any ideas would be greatly appreciated - thanks!

    Read the article

  • how to verify browser IP for server-side web service

    - by Anthony
    I have a web service that needs to be able to verify the end-user's IP that called the server-script that is requesting the web service. Simple layout: Person A goes to Webpage B. Webpage B calls Web Service C to get some info on Person A. Web Service C won't give Webpage B the requested information without confirmation that the request originated from Person A's IP and not someone who has stolen Person A's session. I'm thinking that for a browser-based solution, the original site (Webpage B) can open an iframe that goes to the Web Service's authentication page. A key of some kind is passed to the browser which will some how indicate both the user's IP and Web Page B's IP, so that the Web Service can confirm that no one has nabbed anything. I have two challenges, but I'll stick to the more immediate one first: I'm not sure if my browser-based plan really makes sense. If someone steals the session cookie, how is the Web Service going to know? Would this cookie be held be Web Page B and thus be harder to steal? Is it a sound assumption that a cookie or key held by the server only and not the browser is safe? Also, would the web service, based on the iframe initial connection, be expecting the server/user-ip combo? What I mean is, does the session key provided via the iframe get stored by the web service and the Web Site B shows it has a match? Or is the session key more generic, meaning the web service is passed the key by Website B and the Web Service verifies that this is a valid session key based on what a valid session key should look like?

    Read the article

  • C# Regex stops after first line matched

    - by JD Guzman
    Ok so I have a regex and I need it to find matches in a multiline string. This is the string I am using: Device Identifier: disk0 Device Node: /dev/disk0 Part of Whole: disk0 Device / Media Name: OCZ-VERTEX2 Media Volume Name: Not applicable (no file system) Mounted: Not applicable (no file system) File System: None Content (IOContent): GUID_partition_scheme OS Can Be Installed: No Media Type: Generic Protocol: SATA SMART Status: Verified Total Size: 240.1 GB (240057409536 Bytes) (exactly 468862128 512-Byte-Blocks) Volume Free Space: Not applicable (no file system) Device Block Size: 512 Bytes Read-Only Media: No Read-Only Volume: Not applicable (no file system) Ejectable: No Whole: Yes Internal: Yes Solid State: Yes OS 9 Drivers: No Low Level Format: Not supported Basically I need to separate each line into two groups with the colon as the separator. The regex I am using is: @"([A-Za-z0-9\(\) \-\/]+):([A-Za-z0-9\(\) \-\/]+).*" It does work but only picks up the first line and separates it into the two groups like I want but it stops at that point. I have tried the Multiline option but it doesn't make any difference. I must admit I am new to the regex world. Any help is appreciated.

    Read the article

  • Setting EditText imeOptions to actionNext has no effect

    - by Katedral Pillon
    I have a fairly complex (not really) xml layout file. One of the views is a LinearLayout (v1) with two children: an EditText(v2) and another LinearLayout(v3). The child LinearLayout in turn has an EditText(v4) and an ImageView(v5). For EditText v2 I have imeOptions as android:imeOptions="actionNext" But when I run the app, the keyboard's return does not check to next and I want it to change to next. How do I fix this problem? Also, when user clicks next, I want focus to go to EditText v4. I do I do this? For those who really need to see some code: <LinearLayout android:id="@+id/do_txt_view" android:layout_width="match_parent" android:layout_height="wrap_content" android:background="@color/col6" android:orientation="vertical" android:visibility="gone" > <EditText android:id="@+id/gm_title" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_margin="5dp" android:background="@drawable/coldo_text" android:hint="@string/enter_title" android:maxLines="1" android:imeOptions="actionNext" android:padding="5dp" android:textColor="pigc7" android:textSize="ads2" /> <LinearLayout android:layout_width="match_parent" android:layout_height="100dp" android:orientation="horizontal" > <EditText android:id="@+id/rev_text" android:layout_width="0dp" android:layout_height="match_parent" android:layout_gravity="center_vertical" android:layout_margin="5dp" android:layout_weight="1" android:background="@drawable/coldo_text" android:hint="@string/enter_msg" android:maxLines="2" android:padding="5dp" android:textColor="pigc7" android:textSize="ads2" /> <ImageView android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_gravity="center_vertical" android:background="@drawable/colbtn_r” android:clickable="true" android:onClick=“clickAct” android:paddingLeft="5dp" android:paddingRight="5dp" android:src="@drawable/abcat” /> </LinearLayout> </LinearLayout>

    Read the article

  • Silverlight RIA Services - how to do Windows Authentication?

    - by Gustavo Cavalcanti
    I am building my first Silverlight 3 + RI Services application and need some help. It will be deployed in an controlled corporate intranet, 100% windows clients. I have started from the Silverlight Business Application template. These are my requirements: Upon launch the application needs to recognize the currently logged-in user. The application needs to have access to other properties of the user in AD, such as email, full name, and group membership. Group membership is used to grand certain features in the application. A "login as a different user" link is to be always available - Some machines are available throughout the enterprise, logged-in as a certain generic user (verified by the absence of certain membership groups). In this case one can enter credentials and log in (impersonate) to the application as a user different from the one already logged-into the machine. This user is to be used in service calls I have modified the following in the default Business Application template: App.xaml: appsvc:WindowsAuthentication instead of the default FormsAuthentication Web.config: authentication mode="Windows" With these modifications I resolve requirement #1 (get the currently logged-in user). But when I examine RiaContext.Current.User, I don't have access to other properties from AD, such as group memberships. How can I achieve my other requirements? Thanks for your help.

    Read the article

  • Lazy non-modifiable list in Google Collections

    - by mindas
    I was looking for a decent implementation of a generic lazy non-modifiable list implementation to wrap my search result entries. The unmodifiable part of the task is easy as it can be achieved by Collections.unmodifiableList() so I only need to sort out the the lazy part. Surprisingly, google-collections doesn't have anything to offer; while LazyList from Apache Commons Collections does not support generics. I have found an attempt to build something on top of google-collections but it seems to be incomplete (e.g. does not support size()), outdated (does not compile with 1.0 final) and requiring some external classes, but could be used as a good starting point to build my own class. Is anybody aware of any good implementation of a LazyList? If not, which option do you think is better: write my own implementation, based on google-collections ForwardingList, similar to what Peter Maas did; write my own wrapper around Commons Collections LazyList (the wrapper would only add generics so I don't have to cast everywhere but only in the wrapper itself); just write something on top of java.util.AbstractList; Any other suggestions are welcome.

    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

  • Changing label content programmatically from within a DataTemplate used in a DataGrid column header

    - by iimpact
    I'm dynamically creating DataGrid columns (based on an event from my ViewModel) and programmatically adding them to an existing DataGrid. Each column uses a generic HeaderTemplate by setting it to a DataTemplate that has been identified in the xaml. The DataTemplate contains two labels in which needs their content needs to be changed upon creation of the DataGrid column. How would this be done? I understand that the DataTemplate uses the ContentPresenter but I am having trouble accessing it within a dynamically created DataGrid column. Code is as follows: xaml: (template used to format the DataGrid column header): <DataTemplate x:Key="columnTemplate"> <StackPanel> <Label Padding="0" Name="labelA"/> <Separator HorizontalAlignment="Stretch"/> <Label Padding="0" Name="labelB"/> </StackPanel> </DataTemplate> c#: (used to dynamically create a DataGrid column and add it to an existing DataGrid) var dataTemplate = FindResource("columnTemplate") as DataTemplate; var column = new DataGridTextColumn(); column.HeaderTemplate = dataTemplate; DataGrid1.Columns.Add(column); I would like to then access both labelA and labelB and change the content.

    Read the article

  • How to arrange business logic in a Kohana 3 project

    - by Pekka
    I'm looking for advice, tutorials and links at how to set up a mid-sized web application with Kohana 3. I have implemented MVC patterns in the past but never worked against a "formalized" MVC framework so I'm still getting my head around the terminology - toying around with basic examples, building views and templates, and so on. I'm progressing fairly well but I want to set up a real-world web project (one of my own that I've been planning for quite some time now) as a learning object. I learn best by example, but example-based documentation is a bit sparse for Kohana 3 right now - they say so themselves on the site. While I'm not worried about learning the framework as I go along, I want to make sure the code base is healthily structured from the start - i.e. controllers are split nicely, named well and according to standards, and most importantly the business logic is separated into appropriately sized models. My application could, in its core, be described as a business directory with a range of search and listing functions, and a login area for each entry owner. The actual administrative database backend is already taken care of. Supposing I have all the API worked out and in place already - list all businesses, edit business, list businesses by street name, create offer logged in as business, and so on, and I'm just looking for how to fit the functionality into a MVC pattern and into a Kohana application structure that can be easily extended. Do you know real-life examples of "database-heavy" applications like directories, online communities... with a log-in area built on Kohana 3, preferably Open Source so I could take a peek how they do it? Are there conventions or best practices on how to structure an extendable login area for end users in a Kohana project that is not only able to handle a business directory page, but further products on separate pages as well? Do you know any good resources on building complex applications with Kohana? Have you built something similar and could give me recommendations on a project structure?

    Read the article

  • Response.Redirect in a COM+ Object Called from Classic ASP Page

    - by ajdams
    Basically we moved from IIS 5 to IIS 7 and I am trying to update some of our old COM objects to .NET by rewriting them in C#. What I am have so far is a Classic ASP page calling the COM+ object and then I am trying to do a simple redirect within the COM+ object (this is just for testing purposes, it's not what the object will do eventually). My problem/question is, why does the redirect call not work properly? Am I doing something wrong or can you not redirect within a COM+ object? All that happens is a blank white page comes up and if I check the IIS logs, I see no errors. Here is my code so far: In Classic ASP (the call to COM+) Set oBankReg = CreateObject("BVSRegistration.SignIn") oBankReg.GetBankId(bankid) Code in C# COM object: using System; using System.Web; using System.Text; using System.EnterpriseServices; using System.Collections.Generic; using System.Runtime.InteropServices; [assembly: ApplicationName("BVSRegistration")] [assembly: Description("COM+ upgrade of the BVSRegistration VB6 SignIn.cls.")] [assembly: ApplicationActivation(ActivationOption.Server)] [assembly: ApplicationAccessControl(false, AccessChecksLevel = AccessChecksLevelOption.ApplicationComponent)] namespace BVSRegistration { public class SignIn : ServicedComponent { public void GetBankId(string bankid) { HttpContext.Current.Response.Redirect("http://www.google.com"); } } } Any ideas? Thanks

    Read the article

  • Assembly reference from ASP.NET App_Code directory

    - by Gerald Schneider
    I have trouble getting a custom ObjectDataSource for an asp:ListView control to work. I have the class for the DataSource in the App_Code directory of the web application (as required by the asp:ListView control). using System; using System.Collections.Generic; using System.ComponentModel; using System.Configuration; using System.Data; using System.Data.Common; using System.Web; using System.DirectoryServices; [DataObject] public class UsersDAL { [DataObjectMethod(DataObjectMethodType.Select)] public List<User> LoadAll(int startIndex, int maxRows, string sortedBy) { List<User> users = new List<User>(); DirectoryEntry entry; return users; } } As soon as I add using System.DirectoryServices; the page crashes with this message: Compiler Error Message: CS0234: The type or namespace name 'DirectoryServices' does not exist in the namespace 'System' (are you missing an assembly reference?) Without the usage of System.DirectoryServices the page loads without problems. The reference is there, it is working in classes outside the App_Code directory.

    Read the article

  • Accessing Spring beans from a Tiles view (JSP)

    - by Sinuhe
    In Spring MVC I can access my beans in JSP using JstlView's exposedContextBeanNames (or exposeContextBeansAsAttributes). For example, then, in my JSP I can write (${properties.myProperty). But when the same JSP is a part of a tiles view, these properties aren't accessible. Is possible to configure Tiles properly or access these properties in another way? I'm using Spring MVC 3.0.2 and Tiles 2.2.1. Here's a bit of my configuration: <bean id="tilesViewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver"> <property name="order" value="1"/> <property name="viewClass" value="org.springframework.web.servlet.view.tiles2.TilesView" /> </bean> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/> <property name="order" value="2"/> <property name="prefix" value="/WEB-INF/views/"/> <property name="suffix" value=".jsp"/> <property name="exposedContextBeanNames"> <list><value>properties</value></list> </property> </bean>

    Read the article

  • Signals and Variables in VHDL - Problem

    - by Morano88
    I have a signal and this signal is a bitvector. The length of the bitvector depends on an input n, it is not fixed. In order to find the length, I have to do some computations. Can I define a signal after defining the variables ? It is ggiving me errors when I do that. It is working fine If I keep the signal before the variables .. but I don't want that .. the length of Z depends on the computations of the variables. What is the solution ? library IEEE; use IEEE.STD_LOGIC_1164.ALL; use IEEE.STD_LOGIC_ARITH.ALL; use IEEE.STD_LOGIC_UNSIGNED.ALL; entity BSD_Full_Comp is Generic (n:integer:=8); Port(X, Y : inout std_logic_vector(n-1 downto 0); FZ : out std_logic_vector(1 downto 0)); end BSD_Full_Comp; architecture struct of BSD_Full_Comp is Component BSD_BitComparator Port ( Ai_1 : inout STD_LOGIC; Ai_0 : inout STD_LOGIC; Bi_1 : inout STD_LOGIC; Bi_0 : inout STD_LOGIC; S1 : out STD_LOGIC; S0 : out STD_LOGIC ); END Component; Signal Z : std_logic_vector(2*n-3 downto 0); begin ass : process Variable length : integer := n; Variable pow : integer :=0 ; Variable ZS : integer :=0; begin while length /= 0 loop length := length/2; pow := pow+1; end loop; length := 2 ** pow; ZS := length - n; wait; end process; end struct;

    Read the article

  • Grouped UITableView Footer Sometimes Hidden On Quick Scroll

    - by jdandrea
    OK, this one is a puzzler. There is one similar post but it's not similar enough to count, so I'm posting this one. :) I've got a grouped UITableView with a header and footer. The footer includes two UIButton views, side-by-side. Nothing major. Now … there is a toggle button in a UIToolbar at the bottom for more/less info in this table view. So I build my index paths to delete/insert with fade row animation, all the usual ingredients, sandwiched between beginUpdates and endUpdates calls on the UITableView … and this works fine! In also happens that my footer can sometimes be pushed off past the bottom of the display. Here's where it gets weird. If I drag my finger up the display, scrolling the view upward, I should see that footer eventually, right? Well … most of the time I do. BUT, if I flick my finger up, for a faster scroll, the footer is missing. Even if you try to tap in that area - no response. However, if I scroll back down again, just to hide that footer (or rather hide the area where the footer would normally be), and then scroll back up, it's there once again! This only happens when inserting rows. If I delete rows, the footer stays put … unless of course it was already hidden and I didn't perform the aforementioned incantation to get it back. :) I am trying to trace through this, but to no avail. I suppose tracing through scroll operations is a bit of a crazy proposition! Perhaps some creative logging … suggestions, anyone? Or is this a known issue in 3.1 where row insert/deletes are concerned? (I don't recall seeing it until 3.1.)

    Read the article

  • Maintaining state and data context between requests in ASP.NET + EF4

    - by Nick
    I have a EF4/ASP.NET web application that is structured to use POCOs and generic repositories, based essentially on this excellent article. The application is relatively sophisticated with one page that involves selection and linking of multiple entities to build up a complex user profile. This requires access to multiple entity types (20 or so) and associated repositories across multiple posts. When a repository is first accessed it uses the existing data context if exists, else it creates a new context. The problem is that if the lifetime of the context is only per-request (as suggested in the article) then you have to deal with multiple contexts and the complexity around detaching and attaching entities from contexts. My solution is to share the context between posts by creating a single View Model that includes all required repositories (initialised to share the same context) plus any associated data and store this model in a Session variable, retrieving from Session on subsequent page requests. Therefore maintaining the same context across all posts until the profile is saved. This works fine BUT I am concerned that I don't actually know exactly what is stored in the model session variable or more importantly the size of the Session variable. So two questions I suppose: firstly should I look for a better solution to handle the shared context across posts issue (any suggestions welcome)? And secondly what is actually stored in the Session when it includes a repository plus context? Any help appreciated!

    Read the article

  • Most efficient way to send images across processes

    - by Heinrich Ulbricht
    Goal Pass images generated by one process efficiently and at very high speed to another process. The two processes run on the same machine and on the same desktop. The operating system may be WinXP, Vista and Win7. Detailled description The first process is solely for controlling the communication with a device which produces the images. These images are about 500x300px in size and may be updated up to several hundred times per second. The second process needs these images to display them. The first process uses a third party API to paint the images from the device to a HDC. This HDC has to be provided by me. Note: There is already a connection open between the two processes. They are communicating via anonymous pipes and share memory mapped file views. Thoughts How would I achieve this goal with as little work as possible? And I mean both work for me and the computer. I am using Delphi, so maybe there is some component available for doing this? I think I could always paint to any image component's HDC, save the content to memory stream, copy the contents via the memory mapped file, unpack it on the other side and paint it there to the destination HDC. I also read about a IPicture interface which can be used to marshall images. What are your ideas? I appreciate every thought on this!

    Read the article

  • Change in behaviour & generation of nullreference exception

    - by peril brain
    I made this program 2hr ago and it ran quit well when i confronted this to presaved .xls file. But when i closed that and started new instance,it started generating null refrence exception why??plz explain. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.IO; using System.Threading; using Microsoft.Office.Interop; using Excel = Microsoft.Office.Interop.Excel; namespace svchost { class MainClass { Excel.Application oExcelApp; static void Main(string[] args) { MainClass mc = new MainClass(); while (true) { if (mc.chec()) { Console.WriteLine("RUNNING"); Thread.Sleep(4000); } else { Console.WriteLine("NOT RUNNING"); Thread.Sleep(8000); } } } public bool chec() { try { oExcelApp = (Excel.Application)System.Runtime.InteropServices.Marshal.GetActiveObject("Excel.Application"); Excel.Workbook xlwkbook = (Excel.Workbook)oExcelApp.ActiveWorkbook; //****PROBLEM FROM HERE********* Console.WriteLine(xlwkbook.Name + "\n"); ke kw = new ke(ref oExcelApp,ref xlwkbook); Console.WriteLine(xlwkbook.Author); xlwkbook = null; } catch (Exception ec) { oExcelApp = null; System.GC.Collect(); Console.WriteLine(ec); return false; } oExcelApp = null; System.GC.Collect(); return true; } } class ke { public ke(ref Excel.Application a1, ref Excel.Workbook b1) { Excel.Worksheet ws = (Excel.Worksheet)a1.ActiveSheet; Console.WriteLine(a1.ActiveWorkbook.Name + "\n" + ws.Name); Excel.Range rn; rn = ws.Cells.Find("657/07", Type.Missing, Excel.XlFindLookIn.xlValues, Excel.XlLookAt.xlPart, Excel.XlSearchOrder.xlByRows, Excel.XlSearchDirection.xlNext, false, Type.Missing, Type.Missing); Console.WriteLine(rn.Text); } } }

    Read the article

  • MVC UI with Mock Controllers?

    - by Jaimal Chohan
    I'm working with Aspnet MVC 2 (R2) and at the same time playing about with the whole alt.net stack. One of this things I would like to be able todo is basically write my Views, and be able to interact with them without having to write the controller logic. E.g. I have a view that displays a list of orders and I can click on an order which redirects to another view where I can edit it, but I don't want to get into the nitty gritty of writing the code to actually get a list of orders, or update an existing ordes. I want to do so I can write UI tests in WaitN/AOT/Selenium without having to worry about whats happening underneath, and also It would help drive my controller logic on a need basis as opposed to guess work based of of the supplied screenshots How do you guys accomplish this atm? Can you provide links ot useful blog posts/tools/framework/articles with information on how to accomplish this p.s. I primarly use Rhino Mocks & NUnit but can happliy change to other tools if they support the above better.

    Read the article

  • Comparable and Comparator contract with regards to null

    - by polygenelubricants
    Comparable contract specifies that e.compareTo(null) must throw NullPointerException. From the API: Note that null is not an instance of any class, and e.compareTo(null) should throw a NullPointerException even though e.equals(null) returns false. On the other hand, Comparator API mentions nothing about what needs to happen when comparing null. Consider the following attempt of a generic method that takes a Comparable, and return a Comparator for it that puts null as the minimum element. static <T extends Comparable<? super T>> Comparator<T> nullComparableComparator() { return new Comparator<T>() { @Override public int compare(T el1, T el2) { return el1 == null ? -1 : el2 == null ? +1 : el1.compareTo(el2); } }; } This allows us to do the following: List<Integer> numbers = new ArrayList<Integer>( Arrays.asList(3, 2, 1, null, null, 0) ); Comparator<Integer> numbersComp = nullComparableComparator(); Collections.sort(numbers, numbersComp); System.out.println(numbers); // "[null, null, 0, 1, 2, 3]" List<String> names = new ArrayList<String>( Arrays.asList("Bob", null, "Alice", "Carol") ); Comparator<String> namesComp = nullComparableComparator(); Collections.sort(names, namesComp); System.out.println(names); // "[null, Alice, Bob, Carol]" So the questions are: Is this an acceptable use of a Comparator, or is it violating an unwritten rule regarding comparing null and throwing NullPointerException? Is it ever a good idea to even have to sort a List containing null elements, or is that a sure sign of a design error?

    Read the article

  • Convert query with system objects from SQL 2000 to 2005/2008

    - by Dan
    I have some SQL I need to get working on SQL 2005/2008. The SQL is from SQL 2000 and uses some system objects to make it work. master.dbo.spt_provider_types master.dbo.syscharsets systypes syscolumns sysobjects I know SQL 2005 does no longer use system tables and I can get the same information from views, but I am looking for a solution that will work for both SQL 2000 and 2005/2008. Any ideas? select top 100 percent TABLE_CATALOG = db_name(), TABLE_SCHEMA = user_name(o.uid), TABLE_NAME = o.name, COLUMN_NAME = c.name, ORDINAL_POSITION = convert(int, ( select count(*) from syscolumns sc where sc.id = c.id AND sc.number = c.number AND sc.colid <= c.colid )), IS_COMPUTED = convert(bit, c.iscomputed) from syscolumns c left join syscomments m on c.cdefault = m.id and m.colid = 1, sysobjects o, master.dbo.spt_provider_types d, systypes t, master.dbo.syscharsets a_cha /* charset/1001, not sortorder.*/ where o.name = @table_name and permissions(o.id, c.name) <> 0 and (o.type in ('U','V','S') OR (o.type in ('TF', 'IF') and c.number = 0)) and o.id = c.id and t.xtype = d.ss_dtype and c.length = case when d.fixlen > 0 then d.fixlen else c.length end and c.xusertype = t.xusertype and a_cha.type = 1001 /* type is charset */ and a_cha.id = isnull(convert(tinyint, CollationPropertyFromID(c.collationid, 'sqlcharset')), convert(tinyint, ServerProperty('sqlcharset'))) -- make sure there's one and only one row selected for each column order by 2, 3, c.colorder ) tbl where IS_COMPUTED = 0

    Read the article

  • Erlang, SSH and authorized_keys

    - by Roberto Aloi
    Playing with the ssh and public_key application in Erlang, I've discovered a nice feature. I was trying to connect to my running Erlang SSH daemon by using a rsa key, but the authentication was failing and I was prompted for a password. After some debugging and tracing (and a couple of coffees), I've realized that, for some weird reason, a non valid key for my user was there. The authorized_keys file contained two keys. The wrong one was at some point in the file, while the correct one was appended at the end of the file. Now, the Erlang SSH application, when diffing the provided key with the ones contained in the authorized_keys, it was finding the first entry (completely ignoring the second on - the correct one). Then, it was switching to different authentication mechanism (at first it was trying dsa instead of rsa and then it was prompting for a password). The question is: Is this behavior intended or should the SSH server check for multiple entries for the same user in the *authorized_keys* file? Is this a generic SSH behaviour or it's just specific to the Erlang implementation?

    Read the article

  • Catching a nested-in-template exception [C++]

    - by Karol
    Hello, I have a problem with writing a catch clause for an exception that is a class nested in a template. To be more specific, I have a following definition of the template and exception: /** Generic stack implementation. Accepts std::list, std::deque and std::vector as inner container. */ template < typename T, template < typename Element, typename = std::allocator<Element> > class Container = std::deque > class stack { public: class StackEmptyException { }; ... /** Returns value from the top of the stack. Throws StackEmptyException when the stack is empty. */ T top() const; ... } I have a following template method that I want exception to catch: template <typename Stack> void testTopThrowsStackEmptyExceptionOnEmptyStack() { Stack stack; std::cout << "Testing top throws StackEmptyException on empty stack..."; try { stack.top(); } catch (Stack::StackEmptyException) { // as expected. } std::cout << "success." << std::endl; } When I compile it (-Wall, -pedantic) I get the following error: In function ‘void testTopThrowsStackEmptyExceptionOnEmptyStack()’: error: expected type-specifier error: expected unqualified-id before ‘)’ token === Build finished: 2 errors, 0 warnings === Thanks in advance for any help! What is interesting, if the stack implementation was not a template, then the compiler would accept the code as it is.

    Read the article

  • Autorotation and multiple view controllers

    - by alku83
    I'm creating an iPad application which should only work in portrait and portait upsidedown modes. For performance reasons in my applicationDidFinishLaunching method I'm creating several viewControllers, and adding them to my main window as subviews. I then hide the ones I don't want to see straight away. There is no tab bar or navigation controller. My problem is that only the first viewController seems to be receiving the rotate calls. I have verified this by swapping around the order in which I add the subviews to the main window and NSLog's. Is there some way I can force all the controllers to receive the calls? Some of my views are designed to lay over the top of another view, but this behind view will not always be the same one - so it seems to make sense to have the overlay view in a separate view controller. Am I doing something fundamentally wrong, and that's why it's not behaving as I would expect? EDIT: The accepted answer for this question seems to indicate the exact problem I'm facing: http://stackoverflow.com/questions/548142/uiviewcontroller-rotate-methods

    Read the article

< Previous Page | 483 484 485 486 487 488 489 490 491 492 493 494  | Next Page >