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Search found 50304 results on 2013 pages for 'class variables'.

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  • getelementbyid issue with radio button

    - by Nelson Silva
    I'm trying to make an alert with the value of the selected radio button, but I allways get the first of them, regardless the one I choose...(Acompanhado); html: <form/> <input type="radio" class="simple_form" name="grupo_1" value="Acompanhado" id="saida"/> <span class="texto">Acompanhado</span> <input type="radio" class="simple_form" name="grupo_1" value="Individual" id="saida"/> <span class="texto">Individual</span> </form> js: function save() { var saida_js = document.getElementById('saida').value; alert("Tipo de saida: " + saida_js); } Any idea ?

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  • C++: Can virtual inheritance be detected at compile time?

    - by Tim
    I would like to determine at compile time if a pointer to Derived can be cast from a pointer to Base without dynamic_cast<. Is this possible using templates and metaprogramming? This isn't exactly the same problem as determining if Base is a virtual base class of Derived, because Base could be the super class of a virtual base class of Derived. Thanks, Tim

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  • C# - Dictionary with generic array as value

    - by alhazen
    In my class, I want to use a dictionary with the following declaration: Dictionary<string, T[]> Since the operations of my class are exactly the same for all generic types, I do not wish to define my class as generic (which means I would have to create a separate instance of my class for each generic type I insert into the dictionary ?). One alternative I'm attempting is to use Dictionary<string, object> instead: public void Add<T>(string str, T value) { // Assuming key already exists var array = (T[]) dictionary[str]; array[0] = value; } However, when iterating over the dictionary, how do I cast the object value back to an array ? foreach(string strKey in dictionary.Keys) { var array = (T[]) dictionary[strKey]; // How to cast here ? //... array[0] = default(T); } Thanks.

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  • functional dependencies vs type families

    - by mhwombat
    I'm developing a framework for running experiments with artificial life, and I'm trying to use type families instead of functional dependencies. Type families seems to be the preferred approach among Haskellers, but I've run into a situation where functional dependencies seem like a better fit. Am I missing a trick? Here's the design using type families. (This code compiles OK.) {-# LANGUAGE TypeFamilies, FlexibleContexts #-} import Control.Monad.State (StateT) class Agent a where agentId :: a -> String liveALittle :: Universe u => a -> StateT u IO a -- plus other functions class Universe u where type MyAgent u :: * withAgent :: (MyAgent u -> StateT u IO (MyAgent u)) -> String -> StateT u IO () -- plus other functions data SimpleUniverse = SimpleUniverse { mainDir :: FilePath -- plus other fields } defaultWithAgent :: (MyAgent u -> StateT u IO (MyAgent u)) -> String -> StateT u IO () defaultWithAgent = undefined -- stub -- plus default implementations for other functions -- -- In order to use my framework, the user will need to create a typeclass -- that implements the Agent class... -- data Bug = Bug String deriving (Show, Eq) instance Agent Bug where agentId (Bug s) = s liveALittle bug = return bug -- stub -- -- .. and they'll also need to make SimpleUniverse an instance of Universe -- for their agent type. -- instance Universe SimpleUniverse where type MyAgent SimpleUniverse = Bug withAgent = defaultWithAgent -- boilerplate -- plus similar boilerplate for other functions Is there a way to avoid forcing my users to write those last two lines of boilerplate? Compare with the version using fundeps, below, which seems to make things simpler for my users. (The use of UndecideableInstances may be a red flag.) (This code also compiles OK.) {-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, FlexibleInstances, UndecidableInstances #-} import Control.Monad.State (StateT) class Agent a where agentId :: a -> String liveALittle :: Universe u a => a -> StateT u IO a -- plus other functions class Universe u a | u -> a where withAgent :: Agent a => (a -> StateT u IO a) -> String -> StateT u IO () -- plus other functions data SimpleUniverse = SimpleUniverse { mainDir :: FilePath -- plus other fields } instance Universe SimpleUniverse a where withAgent = undefined -- stub -- plus implementations for other functions -- -- In order to use my framework, the user will need to create a typeclass -- that implements the Agent class... -- data Bug = Bug String deriving (Show, Eq) instance Agent Bug where agentId (Bug s) = s liveALittle bug = return bug -- stub -- -- And now my users only have to write stuff like... -- u :: SimpleUniverse u = SimpleUniverse "mydir"

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  • Form Not Submitting

    - by John
    Hello, When I try to click on the "submit" button for the form below, nothing happens. Any ideas why not? Thanks in advance, John submit.php: <?php require_once "header.php"; $u = $_SESSION['username']; if (!isLoggedIn()) { // user is not logged in. if (isset($_POST['cmdlogin'])) { // retrieve the username and password sent from login form & check the login. if (checkLogin($_POST['username'], $_POST['password'])) { show_userbox2(); } else { echo "Incorrect Login information !"; show_loginform(); } } else { show_loginform(); } } else { . show_userbox2(); } echo '<div class="submittitle">Submit an item.</div>'; echo '<form action="http://www...com/.../submit2.php" method="post"> <input type="hidden" value="'.$_SESSION['loginid'].'" name="uid"> <div class="submissiontitle"><label for="title">Story Title:</label></div> <div class="submissionfield"><input name="title" type="title" id="title" maxlength="1000"></div> <div class="urltitle"><label for="url">Link:</label></div> <div class="urlfield"><input name="url" type="url" id="url" maxlength="500"></div> <div class="submissionbutton"><input name="submit" type="submit" value="Submit"></div> </form> '; ?> submit2.php: <?php //if($_SERVER['REQUEST_METHOD'] == "POST"){header('Location: http://www...com/.../submit2.php');} require_once "header.php"; if (isLoggedIn() == true) { $remove_array = array('http://www.', 'http://', 'https://', 'https://www.', 'www.'); $cleanurl = str_replace($remove_array, "", $_POST['url']); $cleanurl = strtolower($cleanurl); $cleanurl = preg_replace('/\/$/','',$cleanurl); $title = $_POST['title']; //$url = $_POST['url']; $uid = $_POST['uid']; $title = mysql_real_escape_string($title); $cleanurl = mysql_real_escape_string($cleanurl); $site1 = 'http://' . $cleanurl; $displayurl = parse_url($site1, PHP_URL_HOST); function isURL($url1 = NULL) { if($url1==NULL) return false; $protocol = '(http://|https://)'; $allowed = '[-a-z0-9]{1,63}'; $regex = "^". $protocol . // must include the protocol '(' . $allowed . '\.)'. // 1 or several sub domains with a max of 63 chars '[a-z]' . '{2,6}'; // followed by a TLD if(eregi($regex, $url1)==true) return true; else return false; } if(isURL($site1)==true) mysql_query("INSERT INTO submission VALUES (NULL, '$uid', '$title', '$cleanurl', '$displayurl', NULL)"); else echo "<p class=\"topicu\">Not a valid URL.</p>\n"; } else { // user is not loggedin show_loginform(); } if (!isLoggedIn()) { // user is not logged in. if (isset($_POST['cmdlogin'])) { // retrieve the username and password sent from login form & check the login. if (checkLogin($_POST['username'], $_POST['password'])) { show_userbox(); } else { echo "Incorrect Login information !"; show_loginform(); } } else { // User is not logged in and has not pressed the login button // so we show him the loginform show_loginform(); } } else { // The user is already loggedin, so we show the userbox. show_userbox(); } require_once "footer.php"; ?>

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  • wcf possible to override the dipose of proxy

    - by pdiddy
    I'd like to override the Dispose method of generated proxy (ClientBase) because of the fact that disposing of a proxy calls Close and can throw an exception when the channel is faulted. The only way I came up was to create a partial class to my generatedproxy, make it inherit from IDisposable. : public partial class MyServiceProxy : IDisposable { #region IDisposable Members public void Dispose() { if (State != System.ServiceModel.CommunicationState.Faulted) Close(); else Abort(); } #endregion } I did some test and my Dipose method is indeed called. Do you see any issue with this strategy? Also, I don't like the fact that I'll have to create this partial class for every generated proxy. It be nice if I was able to make my proxy inherit from a base class...

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  • How to implement jsf validator?

    - by Krishna
    HI, I want to know how to implement Validator in JSF. What is the advantages of declaring the validator-id. When it will be called in the life cycle?. I have implemented the following code. Please find out what is wrong in the code. I am not seeing it called anywhere in the life cycle. <?xml version="1.0"?> <!DOCTYPE faces-config PUBLIC "-//Sun Microsystems, Inc.//DTD JavaServer Faces Config 1.1//EN" "http://java.sun.com/dtd/web-facesconfig_1_1.dtd"> <faces-config> <lifecycle> <phase-listener>javabeat.net.jsf.JsfPhaseListener</phase-listener> </lifecycle> <validator> <validator-id>JsfValidator</validator-id> <validator-class>javabeat.net.jsf.JsfValidator</validator-class> </validator> <managed-bean> <managed-bean-name>jsfBean</managed-bean-name> <managed-bean-class>javabeat.net.beans.ManagedBean</managed-bean-class> <managed-bean-scope>request</managed-bean-scope> </managed-bean> <navigation-rule> <navigation-case> <from-outcome>success</from-outcome> <to-view-id>success.jsp</to-view-id> </navigation-case> </navigation-rule> </faces-config> public class JsfValidator implements Validator { public JsfValidator() { System.out.println("Inside JsfValidator Constructor"); } @Override public void validate(FacesContext facesContext, UIComponent uiComponent, Object object) throws ValidatorException { System.out.println("Inside Validator"); } }

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  • How to return a value when destroying/cleaning-up an object instance

    - by Mridang Agarwalla
    When I initiate a class in Python, I give it some values. I then call method in the class which does something. Here's a snippet: class TestClass(): def __init__(self): self.counter = 0 def doSomething(self): self.counter = self.counter + 1 print 'Hiya' if __name__ == "__main__": obj = TestClass() obj.doSomething() obj.doSomething() obj.doSomething() print obj.counter As you can see, everytime I call the doSomething method, it prints some text and increments an internal variable i.e. counter. When I initiate the class, i set the counter variable to 0. When I destroy the object, I'd like to return the internal counter variable. What would be a good way of doing this? I wanted to know if there were other ways apart from doing stuff like: accessing the variable directly. Like obj.counter. creating a method like getCounter. Thanks.

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  • Javascript and VERY LONG string

    - by StealthRT
    Hey all, i am having problems with the below code: function showTableData() { var tableArray; var x = 0; var theHTML; for (i = 0; i < 7032; i++) { if (x = 0) { theHTML = '<tr>' + '<th scope="row" class="spec">' + partNum[i] + '</th>' + '<td>' + Msrp[i] + '</td>' + '<td>' + blah[i] + '</td>' + '<td>' + blahs[i] + '</td>' + '</tr>' + theHTML; x++; }else{ theHTML = '<tr>' + '<th scope="row" class="specalt">' + partNum[i] + '</th>' + '<td class="alt">' + Msrp[i] + '</td>' + '<td class="alt">' + blah[i] + '</td>' + '<td class="alt">' + blahs[i] + '</td>' + '</tr>' + theHTML; x--; } } theHTML = '<table id="mytable" cellspacing="0">' + '<tr>' + '<th scope="col" abbr="Configurations" class="nobg">Part Number</th>' + '<th scope="col" abbr="Dual 1.8">Msrp Price</th>' + '<th scope="col" abbr="Dual 2">blahs Price</th>' + '<th scope="col" abbr="Dual 2.5">Low Price</th>' + '</tr>' + theHTML + '</table>'; $('#example').append(theHTML); } </script> <div id="example"> </div> The problem being that the $('#example').append(theHTML); never executes (or shows on the page). I think its because the string is soooooo long! It has over 7,000 items in the array so im not sure if thats the reason or if its something else? Any help would be great! Thanks! David

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  • How to import your own non-packaged Java classes in Jython

    - by thepandaatemyface
    I know in Jython you can do import java.util.Random as Random Random().nextInt() But if I have a class I wrote myself, how can I import it into Jython without putting the class itself in a package? If I have a testclass Test: public class Test { public void foo() { System.out.println("bar"); } } that's not inside a package. Can I even import that into jython by using something along the lines offrom Test import Test?

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  • org.hibernate.PropertyNotFoundException

    - by niru
    hi i am new to hibernate, i m using the following code and getting the following error public class OperProfile { private String empId; private long age; private String name; public long getAge() { return age; } public void setAge(long age) { this.age = age; } public String getEmpId() { return empId; } public void setEmpId(String empId) { this.empId = empId; } public String getName() { return name; } public void setName(String name) { this.name = name; } } i am getting this error org.hibernate.PropertyNotFoundException: Could not find a getter for age in class com.fmr.OperProfile my hbm.xml file is <hibernate-mapping> <class name="com.fmr.OperProfile" table="EMPLOYEE" dynamic-update="true"> <id name="empId" type="java.lang.String" column="EMP_ID"> <generator class="assigned" /> </id> <property name="name" type="java.lang.String" column="NAME"/> <property name=" age" type="java.lang.Long" column="AGE" not-null="true" /> <property name="address1" type="java.lang.String" column="ADDRESS1" /> <property name="address2" type="java.lang.String" column="ADDRESS2" /> <property name="city" type="java.lang.String" column="CITY" /> <property name="state" type="java.lang.String" column="STATE" /> <property name="pincode" type="java.lang.Long" column="PINCODE" /> </class> </hibernate-mapping> please can anyone help me

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  • IOS restkit error

    - by user1302602
    I am sending a Post with object loader and getting this error in output window. FYI, My didFailWithError: delegate never got hit. Not sure why. `objectLoader:didFailWithError:]:` unrecognized selector `sent to class 0x123608` How did i find out what is 0x123608? I set the router in AppDelegate class and Mapping in AppDelegate too. here is a method in my class which inherit RKObjectLoaderDelegate. I am using shared singleton. [[RKObjectManager sharedManager] postObject:review usingBlock:^(RKObjectLoader *loader){ // loader.params=params, loader.objectMapping = [[RKObjectManager sharedManager].mappingProvider objectMappingForClass:[myclass class]]; loader.serializationMIMEType = RKMIMETypeJSON; // We want to send this request as JSON loader.method = RKRequestMethodPOST; loader.serializationMapping = [RKObjectMapping serializationMappingUsingBlock:^(RKObjectMapping* mapping) { [mapping mapAttributes:@"field1", @"field2",@"field3",nil]; }]; loader.targetObject = nil; loader.delegate = self; }]; }

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  • How deserealizing JSON with GSON

    - by loko
    I have one result of APPI http://developer.yahoo.com/geo/placefinder/guide/examples.html, I need to deserealizing the result JSON of example only with GSON http://where.yahooapis.com/geocode?location=San+Francisco,+CA&flags=J&appid=yourappid But i dont now have to do the class for deserealizing one JSON with array This is the reponse: {"ResultSet": {"version":"1.0", "Error":0, "ErrorMessage":"No error", "Locale":"en_US", "Quality":40, "Found":1, "Results":[ {"quality":40, "latitude":"37.779160", "longitude":"-122.420049", "offsetlat":"37.779160", "offsetlon":"-122.420049", "radius":5000, "name":"", "line1":"", "line2":"San Francisco, CA", "line3":"", "line4":"United States", "house":"", "street":"", "xstreet":"", "unittype":"", "unit":"", "postal":"", "neighborhood":"", "city":"San Francisco", "county":"San Francisco County", "state":"California", "country":"United States", "countrycode":"US", "statecode":"CA", "countycode":"", "uzip":"94102", "hash":"C1D313AD706E3B3C", "woeid":12587707, "woetype":9}] } } Im trying to deserealizing of this way but i couldn´t do that, please help me to do the correct class to get the JSON with GSON. public class LocationAddress { private ResultSet resultset; public static class ResultSet{ private String version; private String Error; private String ErrorMessage; private List<Results> results; } public static class Results{ private String quality; private String latitude; private String longitude; public String getQuality() { return quality; } public void setQuality(String quality) { this.quality = quality; } public String getLatitude() { return latitude; } public void setLatitude(String latitude) { this.latitude = latitude; } public String getLongitude() { return longitude; } public void setLongitude(String longitude) { this.longitude = longitude; } } }

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  • another onmouseover problem this one concerns pictures

    - by user334118
    Hi all! have problems with mouseover in Mozilla and Chrome after making it work in IE, for sure I can tell you that my code woked perfectly in Chrome at least, cause thats my default browser and I used it for debuging when creating the javascipt and it worked nicely... until I tried to make it work in IE too. Here I post the full code of the webpage I'm having trouble with. <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebbShop.aspx.cs" Inherits="FSwebportal.WebbShop" %> .prodShow{width: 100%; text-align:center;border:0; float:right; position:inherit; padding-left:310px;} prodFollow{display:block; width:100%; height:100%; position:fixed; overflow:hidden;} orderSett{display:block; position:relative; float:left; padding-top:inherit;} .ShowBig{width:290px;height:290px; padding-top:10px;} .pTb{width:50px;} .order{background-color:Transparent;margin:3px;} .txtArea{border:0;overflow:auto;width:200px;height:100px;} .prodRow{background-image:url("produktbakgrund.png"); background-repeat:repeat;} .row{background-color:Transparent;width:100%;margin: 0px auto;display:inline-table;} .col{background-color:Transparent;width:100%;margin:3px;} <div id="prodFollow"> <table id="dumbTable"> <tr> <td> <img id="sideImg" class="ShowBig" src="" alt=""/> </td> </tr> <tr> <td> <h3><b>Specifikationer:</b></h3> <select name=""> </select> </td> </tr> </table> </div> <table id="itemList" class="prodShow" cellspacing="0"> <thead> <tr class="prodRow"> <th>Bild</th> <th>Förklaring</th> <th>Artikelnummer</th> <th>Pris</th> </tr> </thead> </table> <script type="text/javascript"> function appendRow() { var tbl = document.getElementById('itemList'); var len = <%= aspInfo.Count %>; var arr = new Array(len); var currIndex = 0; var imgID=0; <% for (int x = 0; x < aspInfo.Count; x++) { Response.Write("arr["+x+"]= '"+ aspInfo[x]+"';"); } %> for(row =0; row < arr.length/4;row++) { var rad = tbl.insertRow(tbl.rows.length); rad.setAttribute('class','prodRow'); for (c = 0; c < tbl.rows[row].cells.length; c++) { if(c < 1) { createCell(rad.insertCell(c), arr[currIndex], 'col',imgID); imgID++; } else { if(c < 3) { createCell(rad.insertCell(c),"<Label class=txtArea>" + arr[currIndex] + "</Label>", 'row',imgID); } else { createCell(rad.insertCell(c),"<Label class=txtArea>" + arr[currIndex] + " SKR</Label><br>Antal:<input type=text class=pTb /><input type=button width=100px value='Lägg i varukorg'></input>", 'order',imgID); } } currIndex++; } } } function createCell(cell, text, style,imgID) { if (style == 'col') { var arrLen = <% = largeImg.Count %>; var imgArr = new Array(arrLen); <% for (int x = 0; x < largeImg.Count; x++) { Response.Write("imgArr["+x+"]= '"+ largeImg[x]+"';"); } %> var div = document.createElement('div'); div.setAttribute('class', style); div.setAttribute('className', style); div.innerHTML = "<a href='#'><img id='" + imgID + "' src='" + text + "' onmouseover=javascript:onImg('" + imgArr[imgID] + "') border='0' alt='Animg' /></a>"; cell.appendChild(div); } else { var div = document.createElement('div'); div.setAttribute('class', style); div.setAttribute('className', style); div.innerHTML = text; cell.appendChild(div); } } </script> <script type="text/javascript" language="javascript"> function onImg(bigImg) { var img = document.getElementById('sideImg#'); img.src = bigImg; alert(img.src.toString()); } </script> </form> hope you guys can solve it for me, going mad! best regards David

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  • Android: Help with tabs view

    - by James
    So I'm trying to build a tabs view for an Android app, and for some reason I get a force close every time I try to run it on the emulator. When I run the examples, everything shows fine, so I went as far as to just about copy most of the layout from the examples(a mix of Tabs2.java and Tabs3.java), but for some reason it still wont run, any ideas? Here is my code(List1.class is a copy from the examples for testing purposes). It all compiles fine, just gets a force close the second it starts: package com.jvavrik.gcm; import android.app.TabActivity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.TabHost; import android.widget.TextView; public class GCM extends TabActivity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); final TabHost tabHost = getTabHost(); tabHost.addTab(tabHost.newTabSpec("tab1") .setIndicator("g", getResources().getDrawable(R.drawable.star_big_on)) .setContent(new Intent(this, List1.class))); tabHost.addTab(tabHost.newTabSpec("tab2") .setIndicator("C") .setContent(new Intent(this, List1.class)) ); tabHost.addTab(tabHost.newTabSpec("tab3") .setIndicator("S") .setContent(new Intent(this, List1.class)) ); tabHost.addTab(tabHost.newTabSpec("tab4") .setIndicator("A") .setContent(new Intent(this, List1.class)) ); } }

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  • ahow can I resolve Django Error: str' object has no attribute 'autoescape'?

    - by Angelbit
    Hi have tried to create a inclusion tag on Django but don't work and return str' object has no attribute 'autoescape' this is the code of custom tag: from django import template from quotes.models import Quotes register = template.Library() def show_quote(): quote = Quotes.objects.values('quote', 'author').get(id=0) return {'quote': quote['quote']} register.inclusion_tag('quotes.html')(show_quote) EDIT: Quote class from django.db import models class Quotes(models.Model): quote = models.CharField(max_length=255) author = models.CharField(max_length=100) class Meta: db_table = 'quotes' quotes.html <blockquote id="quotes">{{ quote }}</blockquote>

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  • How to later assign value to optional attribute of NSManagedObject in a NSManagedObjectModel having

    - by Kundan
    I am using coredata framework. In my NSManagedObjectModel i am using three entities that are Class, Student and Score where class and student have one-to-many & inverse relationship and Student and Score have also inverse but one-one relationship. Score entity has all optional attributes and having default '0' decimalVaue, which is not assigned at the time new Student is added. But later i want to assign them score individually and also to particular attribute not all of score attributes in a go. I am able to create and add Students to particular Class but dont have any idea how to call particular student and assign them score. For example I want to assign Score'attribute "dribbling" [there are many attributes like "tackling"] a decimal value to Student "David" of Class "Soccer" ,how i can do that? Thanks in advance for any suggestion.

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  • How do I get started writing a .Net-wrapper around C++ Omniorb-stubs

    - by Superfisi
    Hello there, my job is to access a CPRBA-server-application from .NET 3.5. After evaluating projets like IIOP.Net (undefined state) and products like VisiBroker (expensive) I'd like to do it "by myself" and write a .Net-Wrapper around C++-Stubs generated my Omniidl (the Omniorb IDL to C++ generator). This means writing some kind of layer of managed code (CLI) around the unmanaged C++ code. My question is: Has anyone experience in this topic? I honestly don't know how to do it the best way. Right now I plan to create a managed class for every unmanaged class, each managed class itself has a member to an instance of the unmanaged class, which is not garbage-collected. Is this the right way to do it or am I on the wrong path? Thanks in advance!

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  • asking the container to notify your application whenever a session is about to timeout in Java

    - by user136101
    Which method(s) can be used to ask the container to notify your application whenever a session is about to timeout?(choose all that apply) A. HttpSessionListener.sessionDestroyed -- correct B. HttpSessionBindingListener.valueBound C. HttpSessionBindingListener.valueUnbound -- correct this is kind of round-about but if you have an attribute class this is a way to be informed of a timeout D. HttpSessionBindingEvent.sessionDestroyed -- no such method E. HttpSessionAttributeListener.attributeRemoved -- removing an attribute isn’t tightly associated with a session timeout F. HttpSessionActivationListener.sessionWillPassivate -- session passivation is different than timeout I agree with option A. 1) But C is doubtful How can value unbound be tightly coupled with session timeout.It is just the callback method when an attribute gets removed. 2) and if C is correct, E should also be correct. HttpSessionAttributeListener is just a class that wants to know when any type of attribute has been added, removed, or replaced in a session. It is implemented by any class. HttpSessionBindingListener exists so that the attribute itself can find out when it has been added to or removed from a session and the attribute class must implement this interface to achieve it. Any ideas…

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  • How to handle failure to release a resource which is contained in a smart pointer?

    - by cj
    How should an error during resource deallocation be handled, when the object representing the resource is contained in a shared pointer? Smart pointers are a useful tool to manage resources safely. Examples of such resources are memory, disk files, database connections, or network connections. // open a connection to the local HTTP port boost::shared_ptr<Socket> socket = Socket::connect("localhost:80"); In a typical scenario, the class encapsulating the resource should be noncopyable and polymorphic. A good way to support this is to provide a factory method returning a shared pointer, and declare all constructors non-public. The shared pointers can now be copied from and assigned to freely. The object is automatically destroyed when no reference to it remains, and the destructor then releases the resource. /** A TCP/IP connection. */ class Socket { public: static boost::shared_ptr<Socket> connect(const std::string& address); virtual ~Socket(); protected: Socket(const std::string& address); private: // not implemented Socket(const Socket&); Socket& operator=(const Socket&); }; But there is a problem with this approach. The destructor must not throw, so a failure to release the resource will remain undetected. A common way out of this problem is to add a public method to release the resource. class Socket { public: virtual void close(); // may throw // ... }; Unfortunately, this approach introduces another problem: Our objects may now contain resources which have already been released. This complicates the implementation of the resource class. Even worse, it makes it possible for clients of the class to use it incorrectly. The following example may seem far-fetched, but it is a common pitfall in multi-threaded code. socket->close(); // ... size_t nread = socket->read(&buffer[0], buffer.size()); // wrong use! Either we ensure that the resource is not released before the object is destroyed, thereby losing any way to deal with a failed resource deallocation. Or we provide a way to release the resource explicitly during the object's lifetime, thereby making it possible to use the resource class incorrectly. There is a way out of this dilemma. But the solution involves using a modified shared pointer class. These modifications are likely to be controversial. Typical shared pointer implementations, such as boost::shared_ptr, require that no exception be thrown when their object's destructor is called. Generally, no destructor should ever throw, so this is a reasonable requirement. These implementations also allow a custom deleter function to be specified, which is called in lieu of the destructor when no reference to the object remains. The no-throw requirement is extended to this custom deleter function. The rationale for this requirement is clear: The shared pointer's destructor must not throw. If the deleter function does not throw, nor will the shared pointer's destructor. However, the same holds for other member functions of the shared pointer which lead to resource deallocation, e.g. reset(): If resource deallocation fails, no exception can be thrown. The solution proposed here is to allow custom deleter functions to throw. This means that the modified shared pointer's destructor must catch exceptions thrown by the deleter function. On the other hand, member functions other than the destructor, e.g. reset(), shall not catch exceptions of the deleter function (and their implementation becomes somewhat more complicated). Here is the original example, using a throwing deleter function: /** A TCP/IP connection. */ class Socket { public: static SharedPtr<Socket> connect(const std::string& address); protected: Socket(const std::string& address); virtual Socket() { } private: struct Deleter; // not implemented Socket(const Socket&); Socket& operator=(const Socket&); }; struct Socket::Deleter { void operator()(Socket* socket) { // Close the connection. If an error occurs, delete the socket // and throw an exception. delete socket; } }; SharedPtr<Socket> Socket::connect(const std::string& address) { return SharedPtr<Socket>(new Socket(address), Deleter()); } We can now use reset() to free the resource explicitly. If there is still a reference to the resource in another thread or another part of the program, calling reset() will only decrement the reference count. If this is the last reference to the resource, the resource is released. If resource deallocation fails, an exception is thrown. SharedPtr<Socket> socket = Socket::connect("localhost:80"); // ... socket.reset();

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  • My powershell script wont save a file when run using Task Scheduler, do I need to specify a specific argument?

    - by EGr
    I have a script that downloads a temporary Excel file, copies parts of it to a new file, and saves it to a specific location on the network. The problem I'm having is that the new file is never created/saved. If I run the script locally (through cmd.exe, powershell, or powershell ise), it WILL save the file locally, or to the network. If I try running the script via a schedule or on-demand via Task Scheduler, the temporary file is created, but the final document is never created or saved. Is there a specific argument I need to pass, or anything I could be doing wrong? This is the command I'm currently using: powershell.exe -file C:\path\to\my\powershell\script\thescript.ps1 Since it calls environment variables, and other variables relative to the scripts positon, I also set "Start in" to C:\path\to\my\powershell\script\

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  • prototype findElements querySelectorAll error

    - by JD
    i'm call the "down" function but am getting an invalid argument using 1.6.1_rc2 here's the html snippet: <TR id=000000214A class="activeRow searchResultsDisplayOver" conceptID="0000001KIU"> <TD> <DIV class=gridRowWrapper> <SPAN class=SynDesc>Asymmetric breasts</SPAN> <DIV class=buttonWrapper> <SPAN class=btnAddFav title="Add to Favorites">&nbsp;</SPAN> </DIV> </DIV> </TD> </TR> here's the code: var description = row.down('span.SynDesc').innerHTML; row is a dom reference to the element. prototype is appending a # then the id of the element: findElements: function(root) { root = root || document; var e = this.expression, results; switch (this.mode) { case 'selectorsAPI': if (root !== document) { var oldId = root.id, id = $(root).identify(); id = id.replace(/[\.:]/g, "\\$0"); e = "#" + id + " " + e; } results = $A(root.querySelectorAll(e)).map(Element.extend); <-- e = "#000000214A span.SynDesc" root.id = oldId; return results; case 'xpath': return document._getElementsByXPath(this.xpath, root); default: return this.matcher(root); } i get an "invalid argument" error? if i put a breakpoint before the offending line and change e to be equal to "span.SynDesc" it works fine. help. :)

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  • How can I use BeanUtils copyProperties to copy from boolean to Boolean?

    - by carrier
    BeanUtils copyProperties, out of the box, doesn't seem to handle copying from Boolean object properties to boolean primitive properties. I figured I could create and register a converter to handle this, but that just didn't seem to work. So, how can I use BeanUtils to copy the properties from class Source to class Destination where: public class Destination { private boolean property; public boolean isProperty() { return property; } public void setProperty(boolean property) { this.property = property; } } public class Source{ private Boolean property; public Boolean getProperty() { return property; } public void setProperty(Boolean property) { this.property = property; } }

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  • Is there value in unit testing auto implemented properties

    - by ahsteele
    It seems exceptionally heavy handed but going by the rule anything publicly available should be tested should auto-implemented properties be tested? Customer Class public class Customer { public string EmailAddr { get; set; } } Tested by [TestClass] public class CustomerTests : TestClassBase { [TestMethod] public void CanSetCustomerEmailAddress() { //Arrange Customer customer = new Customer(); //Act customer.EmailAddr = "[email protected]"; //Assert Assert.AreEqual("[email protected]", customer.EmailAddr); } }

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  • Losing data after reading them correct from file

    - by user1388172
    i have the fallowing class of object with a class a data structure which i use in main combined. The ADT(abstract data type) is a linked list. After i read from file the input data and create and object which at print looks just fine after a print. after i push_back() the 3-rd int variable get initializated to 0. So example and code: Example: ex.in: 1 7 31 2 2 2 3 3 3 now i create objects from each line, which at print look as they suppose, but after push_back(): 1 7 0 2 2 0 3 3 0 Class.h: class RAngle { private: int x,y,l,b; public: int solution,prec; RAngle(){ x = y = solution = prec = b = l =0; } RAngle(int i,int j,int k){ x = i; y = j; l = k; solution = 0; prec=0; b=0; } friend ostream& operator << (ostream& out, const RAngle& ra){ out << ra.x << " " << ra.y << " " << ra.l <<endl; return out; } friend istream& operator >>( istream& is, RAngle& ra){ is >> ra.x; is >> ra.y; is >> ra.l; return is ; } }; ADT.h: template <class T> class List { private: struct Elem { T data; Elem* next; }; Elem* first; T pop_front(){ if (first!=NULL) { T aux = first->data; first = first->next; return aux; } T a; return a; } void push_back(T data){ Elem *n = new Elem; n->data = data; n->next = NULL; if (first == NULL) { first = n; return ; } Elem *current; for(current=first;current->next != NULL;current=current->next); current->next = n; } Main.cpp(after i call this function in main which prints object as they suppose to be the x var(from RAngle class) changes to 0 in all cases.) void readData(List <RAngle> &l){ RAngle r; ifstream f_in; f_in.open("ex.in",ios::in); for(int i=0;i<10;++i){ f_in >> r; cout << r; l.push_back(r); }

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