Search Results

Search found 16545 results on 662 pages for 'static keyword'.

Page 277/662 | < Previous Page | 273 274 275 276 277 278 279 280 281 282 283 284  | Next Page >

  • PHP Overloading, singleton instance

    - by jamalali81
    I've sort of created my own MVC framework and am curious as to how other frameworks can send properties from the "controller" to the "view". Zend does something along the lines of $this->view->name = 'value'; My code is: file: services_hosting.php class services_hosting extends controller { function __construct($sMvcName) { parent::__construct($sMvcName); $this->setViewSettings(); } public function setViewSettings() { $p = new property; $p->banner = '/path/to/banners/home.jpg'; } } file: controller.php class controller { public $sMvcName = "home"; function __construct($sMvcName) { if ($sMvcName) { $this->sMvcName = $sMvcName; } include('path/to/views/view.phtml'); } public function renderContent() { include('path/to/views/'.$this->sMvcName.'.phtml'); } } file: property.php class property { private $data = array(); protected static $_instance = null; public static function getInstance() { if (null === self::$_instance) { self::$_instance = new self(); } return self::$_instance; } public function __set($name, $value) { $this->data[$name] = $value; } public function __get($name) { if (array_key_exists($name, $this->data)) { return $this->data[$name]; } } public function __isset($name) { return isset($this->data[$name]); } public function __unset($name) { unset($this->data[$name]); } } In my services_hosting.phtml "view" file I have: <img src="<?php echo $this->p->banner ?>" /> This just does not work. Am I doing something fundamentally wrong or is my logic incorrect? I seem to be going round in circles at the moment. Any help would be very much appreciated.

    Read the article

  • Jboss 6 Cluster Singleton Clustered

    - by DanC
    I am trying to set up a Jboss 6 in a clustered environment, and use it to host clustered stateful singleton EJBs. So far we succesfully installed a Singleton EJB within the cluster, where different entrypoints to our application (through a website deployed on each node) point to a single environment on which the EJB is hosted (thus mantaining the state of static variables). We achieved this using the following configuration: Bean interface: @Remote public interface IUniverse { ... } Bean implementation: @Clustered @Stateful public class Universe implements IUniverse { private static Vector<String> messages = new Vector<String>(); ... } jboss-beans.xml configuration: <deployment xmlns="urn:jboss:bean-deployer:2.0"> <!-- This bean is an example of a clustered singleton --> <bean name="Universe" class="Universe"> </bean> <bean name="UniverseController" class="org.jboss.ha.singleton.HASingletonController"> <property name="HAPartition"><inject bean="HAPartition"/></property> <property name="target"><inject bean="Universe"/></property> <property name="targetStartMethod">startSingleton</property> <property name="targetStopMethod">stopSingleton</property> </bean> </deployment> The main problem for this implementation is that, after the master node (the one that contains the state of the singleton EJB) shuts down gracefuly, the Singleton's state is lost and reset to default. Please note that everything was constructed following the JBoss 5 Clustering documents, as no JBoss 6 documents were found on this subject. Any information on how to solve this problem or where to find JBoss 6 documention on clustering is appreciated.

    Read the article

  • php push 2d array into mysql

    - by john
    Hay All, I cant seem to get my head around this dispite the number to examples i read. Basically I have a 2d array and want to insert it into MySQL. The array contains a few strings. I cant get the following to work... $value = addslashes(serialize($temp3));//temp3 is my 2d array, do i need to use keys? (i am not at the moment) $query = "INSERT INTO table sip (id,keyword,data,flags) VALUES(\"$value\")"; mysql_query($query) or die("Failed Query"); Thanks Guys,

    Read the article

  • How to Inserting message into View that depends on session value. ASP.NET MVC. Best practice

    - by Andrew Florko
    User have to populate multistep questionnaire web-forms and step messages depend on the option chosen by user at the very beginning. Messages are stored in web.config file. I use asp.net mvc project, strong typed views and keep business logic separated from controller in static class. I don't want to make business logic dependency on web.config. Well, I have to insert message into view that depends on session value. There are at least 2 options how to implement this: View model has property that is populated in controller/businessLogic and rendered in view like <%: Model.HelpMessage1 %>. I have to pass web.config values from controller to businessLogic that makes business logic methods signature too complex. I don't want to make configuration source abstract (in order to let business logic read configuration values from its methods directly) also. Create static helper class that is called from view like <%: ViewHelper.HelpMessage1(Model.Option1) %>. But in this case logic what to show seems to be separated into two classes: business logic & viewHelper. What will you suggest? Thank you in advance!

    Read the article

  • Wrong answer on c# application, finding the n prime of a list of prime numbers.

    - by user300484
    Hello, I am new to C# and I am practicing by trying to solve this easy C# problem. This application will receive an "n" number. After receiving this number, the program has to show the n prime of the list of primes. For example, if the user enters "3", the program is supposed to display "5", because 5 is the third prime starting at 2. I koow that something is wrong with my code but I dont know where is the problem and how I can fix it. Can you please tell me? Thank you :P using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace ConsoleApplication1 { class Program { static void Main(string[] args) { Console.WriteLine("Determinar el n-esimo primo."); long n = Convert.ToInt64(Console.ReadLine()); // N lugar de primos long[] array = new long[n]; long c=0; while (c >= 2) { if(siprimo(c++) == true) for (long i = 0; i < n; i++) { array[i] = c; } } Console.WriteLine(array[n - 1]); Console.ReadLine(); } static private bool siprimo(long x) { bool sp = true; for (long k = 2; k <= x / 2; k++) if (x % k == 0) sp = false; return sp; } } }

    Read the article

  • ibatis throwing NullPointerException

    - by Prashant P
    i am trying to test ibatis with DB. I get NullPointerException. Below are the class and ibatis bean config, <select id="getByWorkplaceId" parameterClass="java.lang.Integer" resultMap="result"> select * from WorkDetails where workplaceCode=#workplaceCode# </select> <select id="getWorkplace" resultClass="com.ibatis.text.WorkDetails"> select * from WorkDetails </select> POJO public class WorkplaceDetail implements Serializable { private static final long serialVersionUID = -6760386803958725272L; private int code; private String plant; private String compRegNum; private String numOfEmps; private String typeIndst; private String typeProd; private String note1; private String note2; private String note3; private String note4; private String note5; } DAOimplementation public class WorkplaceDetailImpl implements WorkplaceDetailsDAO { private SqlMapClient sqlMapClient; public void setSqlMapClient(SqlMapClient sqlMapClient) { this.sqlMapClient = sqlMapClient; } @Override public WorkplaceDetail getWorkplaceDetail(int code) { WorkplaceDetail workplaceDetail=new WorkplaceDetail(); try{ **workplaceDetail= (WorkplaceDetail) this.sqlMapClient.queryForObject("workplaceDetail.getByWorkplaceId", code);** }catch (SQLException sqlex){ sqlex.printStackTrace(); } return workplaceDetail; } TestCode public class TestDAO { public static void main(String args[]) throws Exception{ WorkplaceDetail wd = new WorkplaceDetail(126, "Hoonkee", "1234", "22", "Service", "Tele", "hsgd","hsgd","hsgd","hsgd","hsgd"); WorkplaceDetailImpl impl= new WorkplaceDetailImpl(); **impl.getWorkplaceDetail(wd.getCode());** impl.saveOrUpdateWorkplaceDetails(wd); System.out.println("dhsd"+impl); } } I want to select and insert. I have marked as ** ** as a point of exception in above code Exception in thread "main" java.lang.NullPointerException at com.ibatis.text.WorkplaceDetailImpl.getWorkplaceDetail(WorkplaceDetailImpl.java:19) at com.ibatis.text.TestDAO.main(TestDAO.java:11)

    Read the article

  • xcode project-/target-settings-syntax for linker flag force_load on iPhone

    - by Kaiserludi
    Hi all. I am confronted with the double bind, that on the one hand for one of the 3rd party static libraries, my iPhone application uses, the linker flag -all_load has to be set in the application project- or target settings, otherwise the app crashes at runtime not finding some symbols, called internally from the lib, on the other hand for another 3rd party static lib -all_load must not be set on application level, or the app won't build thanks to a "duplicate symbols"-linker error. To solve this issue I now want to use force_load instant of load_all, as it due to documentation it does the same like all_load, but only for the passed path or lib-file, instead of all libs. The problem with force_load is, I do not have a clue, how to pass a path or file as parameter with it, when passing it via xcode project- or target-settings. All syntax-possibilities coming to my mind either lead into xcode thinking its another linker flag instead of a parameter to the previous one, or the linker is throwing syntax related errors or the flag simply does nothing at all in comparison to not being set. I also opened the .pbxproj-file in a text-editor to edit it to the correct command line syntax manually, but when reloading the project with xcode, it auto changes the syntax into interpreting the parameter to force_load as a separate flag. Anyone having an idea on this issue? Thx, Kaiserludi.

    Read the article

  • serial port does not exist in current context: c#

    - by I__
    here's the code: using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Threading; namespace WindowsFormsApplication1 { public partial class Form1 : Form { public Form1() { InitializeComponent(); } public class ThreadWork { private static SerialPort serialPort1; public static void DoWork() { serialPort1.Open(); serialPort1.Write("AT+CMGF=1\r\n"); //Thread.Sleep(500); serialPort1.Write("AT+CNMI=2,2\r\n"); //Thread.Sleep(500); serialPort1.Write("AT+CSCA=\"+4790002100\"\r\n"); //Thread.Sleep(500); serialPort1.DataReceived += serialPort1_DataReceived_1; } } private void Form1_Load(object sender, EventArgs e) { ThreadStart myThreadDelegate = new ThreadStart(ThreadWork.DoWork); Thread myThread = new Thread(myThreadDelegate); myThread.Start(); } private void serialPort1_DataReceived_1(object sender, System.IO.Ports.SerialDataReceivedEventArgs e) { string response = serialPort1.ReadLine(); this.BeginInvoke(new MethodInvoker(() => textBox1.AppendText(response + "\r\n"))); } } } and i get an error on this line: string response = serialPort1.ReadLine(); it says:: Error 1 The name 'serialPort1' does not exist in the current context C:\Users\alexluvsdanielle\AppData\Local\Temporary Projects\WindowsFormsApplication1\Form1.cs 44 31 WindowsFormsApplication1 what am i doing wrong?

    Read the article

  • colorbox not displaying first caption from flickr gallery integration

    - by Mark
    I am pulling small thumbnails into my page from the flickr API, and using Colorbox to display larger thumbnails and captions from the title attribute. Using the API with C#. However, on the first instance of opening colorbox it does not display the caption from the anchors title attribute. If you click next or previous then it appears. The actual caption is physically there in the source code, just not getting put into the colorbox window. Demo here, if you click on a thumbnail you will see there is no caption, click next then prev and it will appear. Here's the code: <script type="text/javascript"> $(function() { $("a[rel='group']").colorbox({ opacity: 0.75 }); }); </script> <a href='http://farm6.static.flickr.com/5015/5511378425_e63d4a62f7.jpg' title='Little Hermit (Peter Dunn)' rel='group' class='tooltip'> <img src='http://farm6.static.flickr.com/5015/5511378425_e63d4a62f7_s.jpg' alt='Little Hermit (Peter Dunn)' /> </a> If i view source, the title attribute is populated with the caption, but if i ook in firebug it is not in the colorbox code. Any help on this would be great Ive ran out of ideas!

    Read the article

  • Problem creating a custom input element using FluentHtml (MVCContrib)

    - by seth
    Hi there, I just recently started dabbling in ASP.NET MVC 1.0 and came across the wonderful MVCContrib. I had originally gone down the path of creating some extended html helpers, but after finding FluentHTML decided to try my hand at creating a custom input element. Basically I am wanting to ultimately create several custom input elements to make it easier for some other devs on the project I'm working on to add their input fields to the page and have all of my preferred markup to render for them. So, in short, I'd like to wrap certain input elements with additional markup.. A TextBox would be wrapped in an <li /> for example. I've created my custom input elements following Tim Scott's answer in another question on here: DRY in the MVC View. So, to further elaborate, I've created my class, "TextBoxListItem": public class TextBoxListItem : TextInput<TextBox> { public TextBoxListItem (string name) : base(HtmlInputType.Text, name) { } public TextBoxListItem (string name, MemberExpression forMember, IEnumerable<IBehaviorMarker> behaviors) : base(HtmlInputType.Text, name, forMember, behaviors) { } public override string ToString() { var liBuilder = new TagBuilder(HtmlTag.ListItem); liBuilder.InnerHtml = ToString(); return liBuilder.ToString(TagRenderMode.SelfClosing); } } I've also added it to my ViewModelContainerExtensions class: public static TextBox TextBoxListItem<T>(this IViewModelContainer<T> view, Expression<Func<T, object>> expression) where T : class { return new TextBoxListItem(expression.GetNameFor(view), expression.GetMemberExpression(), view.Behaviors) .Value(expression.GetValueFrom(view.ViewModel)); } And lastly, I've added it to ViewDataContainerExtensions as well: public static TextBox TextBoxListItem(this IViewDataContainer view, string name) { return new TextBox(name).Value(view.ViewData.Eval(name)); } I'm calling it in my view like so: <%= this.TextBoxListItem("username").Label("Username:") %> Anyway, I'm not getting anything other than the standard FluentHTML TextBox, not wrapped in <li></li> elements. What am I missing here? Thanks very much for any assistance.

    Read the article

  • Mysql advanced SELECT, or multiple SELECTS? Movies keywords

    - by Supyxy
    I have a mysql database with movies as follows: MOVIES(id,title) KEYWORDS_TABLE(id,key_id) [id is referenced to movies.id, key_id is refernced to keywords.id] KEYWORDS(id,keyword) //this doesn't matter on my example.. Basically i have movies with their titles and plot keywords for each one, i want to select all movies that have the same keywords with with a given movie id. I tried something like: SELECT key_id FROM keywords_table WHERE id=9 doing that in php and storing all the IDs in an array $key_id.. then i build another select that looks like: SELECT movies.title FROM movies,keywords_table WHERE keywords_table.key_id=$key_id[1] OR keywords_table.key_id=$key_id[2] OR ......... OR keywords_table.key_id=$key_id[n] This kinda works but it takes too much time as we talk about a database with thousands of thousands of records. So, any suggestions?? thanks!

    Read the article

  • Possible to write an Extension Method for ASP.NET's Html.ActionLink() method?

    - by Pretzel
    Right now, I'm trying to work around an IE6/7 bug which requires the wrapping of the </a closing tag with this IE specific comment to make some drop-down menu work: <!--[if IE 7]><!--></a><!--<![endif]--> Unfortunately, I cannot inject this directly into my View page code like this: <%= Html.ActionLink("LinkName<!--[if IE 7]><!--></a><!--<![endif]-->","Action","Controller") %> As Html.ActionLink will do the safe thing and filter out the comment to prevent a Javascript injection attack. Ok, cool. I'm fine with that. Good design decision. What I'd like to do is write an Extension Method to this, but the process is eluding me as I haven't done this before. I thought this would work, but Intellisense doesn't seem to be picking up this Extension method that I've written. public static class MyLinkExtensions { public static string ActionLinkIE(this HtmlHelper htmlHelper, string linkText, string actionName, string controllerName) { return LinkExtensions.ActionLink(htmlHelper, linkText, actionName, controllerName). Replace(@"</a>", @"<!--[if IE 7]><!--></a><!--<![endif]-->"); } } Any suggestions?

    Read the article

  • Different behaviour of method overloading in C#

    - by Wondering
    Hi All, I was going through C# Brainteasers(http://www.yoda.arachsys.com/csharp/teasers.html) and came accross one question:what should be the o/p of below code class Base { public virtual void Foo(int x) { Console.WriteLine ("Base.Foo(int)"); } } class Derived : Base { public override void Foo(int x) { Console.WriteLine ("Derived.Foo(int)"); } public void Foo(object o) { Console.WriteLine ("Derived.Foo(object)"); } } class Test { static void Main() { Derived d = new Derived(); int i = 10; d.Foo(i); // it prints ("Derived.Foo(object)" } } but if I change the code to enter code here class Derived { public void Foo(int x) { Console.WriteLine("Derived.Foo(int)"); } public void Foo(object o) { Console.WriteLine("Derived.Foo(object)"); } } class Program { static void Main(string[] args) { Derived d = new Derived(); int i = 10; d.Foo(i); // prints Derived.Foo(int)"); Console.ReadKey(); } } I want to why the o/p is getting changde when we are inheriting vs not inheriting , why method overloading is behaving differently in both the cases

    Read the article

  • Scala type inference failure on "? extends" in Java code

    - by oxbow_lakes
    I have the following simple Java code: package testj; import java.util.*; public class Query<T> { private static List<Object> l = Arrays.<Object>asList(1, "Hello", 3.0); private final Class<? extends T> clazz; public static Query<Object> newQuery() { return new Query<Object>(Object.class); } public Query(Class<? extends T> clazz) { this.clazz = clazz; } public <S extends T> Query<S> refine(Class<? extends S> clazz) { return new Query<S>(clazz); } public List<T> run() { List<T> r = new LinkedList<T>(); for (Object o : l) { if (clazz.isInstance(o)) r.add(clazz.cast(o)); } return r; } } I can call this from Java as follows: Query<String> sq = Query.newQuery().refine(String.class); //NOTE NO <String> But if I try and do the same from Scala: val sq = Query.newQuery().refine(classOf[String]) I get the following error: error: type mismatch found :lang.this.class[scala.this.Predef.String] required: lang.this.class[?0] forSome{ type ?0 <: ? } val sq = Query.newQuery().refine(classOf[String]) This is only fixed by the insertion of the correct type parameter! val sq = Query.newQuery().refine[String](classOf[String]) Why can't scala infer this from my argument? Note I am using Scala 2.7

    Read the article

  • one table is shared between several websites

    - by sami
    I have a static table that's shared by several websites. By static, I mean that the data is read but never updated by the websites. Currently, all websites are served from the same server but that may change. I want to minimize the need for creating/maintaining this table for each of the websites, so I thought about turning it to an xml file that's stored in a shared library that all websites have access to. The problem is I use an ORM and use forign key constraints to ensure integrity of the ids used from that table, so by removing that table out of the MySQL database into an XML file, will this affect the integrity of the ids coming from that table? My table looks like this <table name="entry"> <column name="id" type="INTEGER" primaryKey="true" autoIncrement="true" /> <column name="title" type="VARCHAR" size="500" required="true" /> </table> and I use it as a foreign key in other tables <table name="refer"> <column name="id" type="INTEGER" primaryKey="true" autoIncrement="true" /> <column name="linkto" type="INTEGER"/> <foreign-key foreignTable="entry"> <reference local="linkto" foreign="id" /> </foreign-key> </table> So I'm wondering if I remove that table out of the database, is there a way to retain that referential integrity? And of course are these any other efficient ways to do the same thing? I just don't want to have to repeat that table for several websites.

    Read the article

  • why the main method are not covered? urgent, please help me

    - by Mike.Huang
    main method: public static void main(String[] args) throws Exception { if (args.length != EXPECTED_NUMBER_OF_ARGUMENTS) { System.err.println("Usage - java XFRCompiler ConfigXML PackageXML XFR"); } String configXML = args[0]; String packageXML = args[1]; String xfr = args[2]; AutoConfigCompiler compiler = new AutoConfigCompiler(); compiler.setConfigDocument(loadDocument(configXML)); compiler.setPackageInfoDoc(loadDocument(packageXML)); // compiler.setVisiblityDoc(loadDocument("VisibilityFilter.xml")); compiler.compileModel(xfr); } private static Document loadDocument(String fileName) throws Exception { TXDOMParser parser = (TXDOMParser) ParserFactory.makeParser(TXDOMParser.class.getName()); InputSource source = new InputSource(new FileInputStream(fileName)); parser.parse(source); return parser.getDocument(); } testcase: @Test public void testCompileModel() throws Exception { // construct parameters URL configFile = Thread.currentThread().getContextClassLoader().getResource("Ford_2008_Mustang_Config.xml"); URL packageFile = Thread.currentThread().getContextClassLoader().getResource("Ford_2008_Mustang_Package.xml"); File tmpFile = new File("Ford_2008_Mustang_tmp.xfr"); if(!tmpFile.exists()) { tmpFile.createNewFile(); } String[] args = new String[]{configFile.getPath(),packageFile.getPath(),tmpFile.getPath()}; try { // test main method XFRCompiler.main(args); } catch (Exception e) { assertTrue(true); } try { // test args length is less than 3 XFRCompiler.main(new String[]{"",""}); } catch (Exception e) { assertTrue(true); } tmpFile.delete(); } coverage outputs displayed as the lines from “String configXML = args[0];" in main method are not covered

    Read the article

  • Can't decrypt after encrypting with blowfish Java

    - by user2030599
    Hello i'm new to Java and i have the following problem: i'm trying to encrypt the password of a user using the blowfish algorithm, but when i try to decrypt it back to check the authentication it fails to decrypt it for some reason. public static String encryptBlowFish(String to_encrypt, String salt){ String dbpassword = null; try{ SecretKeySpec skeySpec = new SecretKeySpec( salt.getBytes(), "Blowfish" ); // Instantiate the cipher. Cipher cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding"); cipher.init(Cipher.ENCRYPT_MODE, skeySpec); //byte[] encrypted = cipher.doFinal( URLEncoder.encode(data).getBytes() ); byte[] encrypted = cipher.doFinal( to_encrypt.getBytes() ); dbpassword = new String(encrypted); } catch (Exception e) { System.out.println("Exception while encrypting"); e.printStackTrace(); dbpassword = null; } finally { return dbpassword; } } public static String decryptBlowFish(String to_decrypt, String salt){ String dbpassword = null; try{ SecretKeySpec skeySpec = new SecretKeySpec( salt.getBytes(), "Blowfish" ); // Instantiate the cipher. Cipher cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding"); cipher.init(Cipher.DECRYPT_MODE, skeySpec); //byte[] encrypted = cipher.doFinal( URLEncoder.encode(data).getBytes() ); byte[] encrypted = cipher.doFinal( to_decrypt.getBytes() ); dbpassword = new String(encrypted); } catch (Exception e) { System.out.println("Exception while decrypting"); e.printStackTrace(); dbpassword = null; } finally { return dbpassword; } } When i call the decrypt function it gives me the following error: java.security.InvalidKeyException: Parameters missing Any ideas? Thank you

    Read the article

  • how to query with child relations to same table and order this correctly

    - by robertpnl
    Hi, Take this table: id name sub_id --------------------------- 1 A (null) 2 B (null) 3 A2 1 4 A3 1 The sub_id column is a relation to his owm table, to column ID. subid --- 0:1 --- id Now I have the problem to make a correctly SELECT query to show that the child rows (which sub_id is not null) directly selected under his parent row. So this must be a correctly order: 1 A (null) 3 A2 1 4 A3 1 2 B (null) A normal SELECT order the id. But how or which keyword help me to order this correctly? JOIN isn't possible I think because I want to get all the rows seperated. Because the rows will be displayed on a Gridview (ASP.Net) with EntityDataSource but the child rows must be displayed directly under his parent. Thank you.

    Read the article

  • forcing stack w/i 32bit when -m64 -mcmodel=small

    - by chaosless
    have C sources that must compile in 32bit and 64bit for multiple platforms. structure that takes the address of a buffer - need to fit address in a 32bit value. obviously where possible these structures will use natural sized void * or char * pointers. however for some parts an api specifies the size of these pointers as 32bit. on x86_64 linux with -m64 -mcmodel=small tboth static data and malloc()'d data fit within the 2Gb range. data on the stack, however, still starts in high memory. so given a small utility _to_32() such as: int _to_32( long l ) { int i = l & 0xffffffff; assert( i == l ); return i; } then: char *cp = malloc( 100 ); int a = _to_32( cp ); will work reliably, as would: static char buff[ 100 ]; int a = _to_32( buff ); but: char buff[ 100 ]; int a = _to_32( buff ); will fail the assert(). anyone have a solution for this without writing custom linker scripts? or any ideas how to arrange the linker section for stack data, would appear it is being put in this section in the linker script: .lbss : { *(.dynlbss) *(.lbss .lbss.* .gnu.linkonce.lb.*) *(LARGE_COMMON) } thanks!

    Read the article

  • User defined literal arguments are not constexpr?

    - by Pubby
    I'm testing out user defined literals. I want to make _fac return the factorial of the number. Having it call a constexpr function works, however it doesn't let me do it with templates as the compiler complains that the arguments are not and cannot be constexpr. I'm confused by this - aren't literals constant expressions? The 5 in 5_fac is always a literal that can be evaluated during compile time, so why can't I use it as such? First method: constexpr int factorial_function(int x) { return (x > 0) ? x * factorial_function(x - 1) : 1; } constexpr int operator "" _fac(unsigned long long x) { return factorial_function(x); // this works } Second method: template <int N> struct factorial { static const unsigned int value = N * factorial<N - 1>::value; }; template <> struct factorial<0> { static const unsigned int value = 1; }; constexpr int operator "" _fac(unsigned long long x) { return factorial_template<x>::value; // doesn't work - x is not a constexpr }

    Read the article

  • Why my object sees variables which were not given to it in the constructor?

    - by Roman
    I have the following code. Which is "correct" and which I do not understand: private static void updateGUI(final int i, final JLabel label) { SwingUtilities.invokeLater( new Runnable() { public void run() { label.setText("You have " + i + " seconds."); } } ); } I create a new instance of the Runnable class and then in the run method of this instance I use variables label and i. It works, but I do not understand why it work. Why the considered object sees values of these variables. According to my understanding the code should look like that (and its wrong): private static void updateGUI(final int i, final JLabel label) { SwingUtilities.invokeLater(new Runnable(i,label) { public Runnable(int i, JLabel label) { this.i = i; this.label = label; } public void run() { label.setText("You have " + i + " seconds."); } }); } So, I would give the i and label variables to the constructor so the object can access them... By the way, in the updateGUI I use final before the i and label. I think I used final because compiler wanted that. But I do not understand why.

    Read the article

  • Recursion in prepared statements

    - by Rob
    I've been using PDO and preparing all my statements primarily for security reasons. However, I have a part of my code that does execute the same statement many times with different parameters, and I thought this would be where the prepared statements really shine. But they actually break the code... The basic logic of the code is this. function someFunction($something) { global $pdo; $array = array(); static $handle = null; if (!$handle) { $handle = $pdo->prepare("A STATEMENT WITH :a_param"); } $handle->bindValue(":a_param", $something); if ($handle->execute()) { while ($row = $handle->fetch()) { $array[] = someFunction($row['blah']); } } return $array; } It looked fine to me, but it was missing out a lot of rows. Eventually I realised that the statement handle was being changed (executed with different param), which means the call to fetch in the while loop will only ever work once, then the function calls itself again, and the result set is changed. So I am wondering what's the best way of using PDO prepared statements in a recursive way. One way could be to use fetchAll(), but it says in the manual that has a substantial overhead. The whole point of this is to make it more efficient. The other thing I could do is not reuse a static handle, and instead make a new one every time. I believe that since the query string is the same, internally the MySQL driver will be using a prepared statement anyway, so there is just the small overhead of creating a new handle on each recursive call. Personally I think that defeats the point. Or is there some way of rewriting this?

    Read the article

  • Design: How to declare a specialized memory handler class

    - by Michael Dorgan
    On an embedded type system, I have created a Small Object Allocator that piggy backs on top of a standard memory allocation system. This allocator is a Boost::simple_segregated_storage< class and it does exactly what I need - O(1) alloc/dealloc time on small objects at the cost of a touch of internal fragmentation. My question is how best to declare it. Right now, it's scope static declared in our mem code module, which is probably fine, but it feels a bit exposed there and is also now linked to that module forever. Normally, I declare it as a monostate or a singleton, but this uses the dynamic memory allocator (where this is located.) Furthermore, our dynamic memory allocator is being initialized and used before static object initialization occurs on our system (as again, the memory manager is pretty much the most fundamental component of an engine.) To get around this catch 22, I added an extra 'if the small memory allocator exists' to see if the small object allocator exists yet. That if that now must be run on every small object allocation. In the scheme of things, this is nearly negligable, but it still bothers me. So the question is, is there a better way to declare this portion of the memory manager that helps decouple it from the memory module and perhaps not costing that extra isinitialized() if statement? If this method uses dynamic memory, please explain how to get around lack of initialization of the small object portion of the manager.

    Read the article

  • Lucene Query Syntax

    - by Don
    Hi, I'm trying to use Lucene to query a domain that has the following structure Student 1-------* Attendance *---------1 Course The data in the domain is summarised below Course.name Attendance.mandatory Student.name ------------------------------------------------- cooking N Bob art Y Bob If I execute the query "courseName:cooking AND mandatory:Y" it returns Bob, because Bob is attending the cooking course, and Bob is also attending a mandatory course. However, what I really want to query for is "students attending a mandatory cooking course", which in this case would return nobody. Is it possible to formulate this as a Lucene query? I'm actually using Compass, rather than Lucene directly, so I can use either CompassQueryBuilder or Lucene's query language. For the sake of completeness, the domain classes themselves are shown below. These classes are Grails domain classes, but I'm using the standard Compass annotations and Lucene query syntax. @Searchable class Student { @SearchableProperty(accessor = 'property') String name static hasMany = [attendances: Attendance] @SearchableId(accessor = 'property') Long id @SearchableComponent Set<Attendance> getAttendances() { return attendances } } @Searchable(root = false) class Attendance { static belongsTo = [student: Student, course: Course] @SearchableProperty(accessor = 'property') String mandatory = "Y" @SearchableId(accessor = 'property') Long id @SearchableComponent Course getCourse() { return course } } @Searchable(root = false) class Course { @SearchableProperty(accessor = 'property', name = "courseName") String name @SearchableId(accessor = 'property') Long id }

    Read the article

  • Proper way of naming your Java Google App Engine Project

    - by Saif Bechan
    I am starting out with Google's App Engine in Java. I have seen the tutorial video but I do not understand the naming of the project package. It is going to be a guestbook, that's why the name is guestbook, I understand that part. But after that I see package name. 1)Is that something you import into the project, or is is something you create. I have seen this a lot in projects, something like com.xxx.xxx. 2)How do you name this type of thing or is this an import. I have looked at another tutorial there they take the naming to a whole new level. The name of both the project and the package is de.vogella.gae.java.todo. 3)What does this mean in java terms. 4)Maybe one of you can help me with this specific project I want to start. I want to create a Google App project that for now only serves static files. I will leave the project empty and just put all my static files in the war directory of the project. I want the domain name to be mydomainstatic

    Read the article

< Previous Page | 273 274 275 276 277 278 279 280 281 282 283 284  | Next Page >