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  • JSF2 and Richfaces 3.3.3 application on tomcat 6.0 crashes with a StackOverflowError

    - by Vivek Madapura V
    Hi, I am using JSF 2 and richfaces 3.3.3 for an application hosted on tomcat 6.0.20. The application crashes as soon as a request is made via the browser (Mozilla and IE). My web.xml looks like this: <?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5"> <display-name>TestJSF</display-name> <welcome-file-list> <welcome-file>pages/login.xhtml</welcome-file> </welcome-file-list> <servlet> <servlet-name>Faces Servlet</servlet-name> <servlet-class>javax.faces.webapp.FacesServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>Faces Servlet</servlet-name> <url-pattern>/faces/*</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>Faces Servlet</servlet-name> <url-pattern>*.xhtml</url-pattern> </servlet-mapping> <context-param> <description>State saving method: 'client' or 'server' (=default). See JSF Specification 2.5.2</description> <param-name>javax.faces.STATE_SAVING_METHOD</param-name> <param-value>server</param-value> </context-param> <context-param> <param-name>javax.faces.DISABLE_FACELET_JSF_VIEWHANDLER</param-name> <param-value>true</param-value> </context-param> <context-param> <param-name>org.richfaces.SKIN</param-name> <param-value>blueSky</param-value> </context-param> <context-param> <param-name>org.richfaces.CONTROL_SKINNING</param-name> <param-value>enable</param-value> </context-param> <context-param> <param-name>javax.faces.DEFAULT_SUFFIX</param-name> <param-value>.xhtml</param-value> </context-param> <context-param> <param-name>javax.faces.FACELETS_SKIP_COMMENTS</param-name> <param-value>true</param-value> </context-param> <listener> <listener-class>com.sun.faces.config.ConfigureListener</listener-class> </listener> <filter> <display-name>RichFaces Filter</display-name> <filter-name>richfaces</filter-name> <filter-class>org.ajax4jsf.Filter</filter-class> </filter> <filter-mapping> <filter-name>richfaces</filter-name> <servlet-name>Faces Servlet</servlet-name> <dispatcher>REQUEST</dispatcher> <dispatcher>FORWARD</dispatcher> <dispatcher>INCLUDE</dispatcher> </filter-mapping> </web-app> The exception is javax.servlet.ServletException: Servlet execution threw an exception org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:530) com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:542) com.sun.faces.application.view.JspViewHandlingStrategy.executePageToBuildView(JspViewHandlingStrategy.java:359) com.sun.faces.application.view.JspViewHandlingStrategy.buildView(JspViewHandlingStrategy.java:150) com.sun.faces.application.view.JspViewHandlingStrategy.renderView(JspViewHandlingStrategy.java:190) com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:127) org.ajax4jsf.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:100) org.ajax4jsf.application.AjaxViewHandler.renderView(AjaxViewHandler.java:176) com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:117) com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97) com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:135) javax.faces.webapp.FacesServlet.service(FacesServlet.java:309) The stack trace is recursively logged with this until the StackOverflowError occurrs. If I remove all the configurations related to Richfaces, the application works like charm. Any advice is much appreciated.

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  • What is Perl's equivalent to awk's /text/,/END/ ?

    - by kSiR
    I am looking to replace a nasty shell script that uses awk to trim down some HTML. The problem is I cannot find anything in Perl that does the aforementioned function awk '/<TABLE\ WIDTH\=\"100\%\" BORDER\=1\ CELLSPACING\=0><TR\ class\=\"tabhead\"><TH>State<\/TH>/,/END/' How can I do this in Perl? the expected output would be <TABLE WIDTH="100%" BORDER=1 CELLSPACING=0><TR class="tabhead"><TH>State</TH> The Perl flipflop operator gives me WAY more. (Everything between the asterisks is junk) *<h2>Browse Monitors (1 out of 497)</h2><br><font size="-1" style="font-weight:normal"> Use the <A HREF=/SiteScope/cgi/go.exe/SiteScope?page=monitorSummary&account=login15 >Monitor Description Report</a> to view current monitor configuration settings.</font>*<TABLE WIDTH="100%" BORDER=1 CELLSPACING=0><TR class="tabhead"><TH>State</TH>

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  • Setting classpath java for use in Runtime.exec

    - by phil swenson
    I am trying to spawn a process using Runtime.exec. I want to use my current classpath : System.getProperty("java.class.path") Unfortunately, I am having all kinds of issues. When it works on my mac, it doesn't work on Windows. And doesn't work on my mac ever when there is a space in the classpath. The error I always get is ClassDefNotFound, so it's related to how I'm building and passing in the classpath. here is some sample code: String startClass = "com.test.MyClass" String javaHome = System.getProperty("java.home"); String javaCmd = javaHome + "/bin/java"; String classPath = "-Djava.class.path=" + System.getProperty("java.class.path"); String[] commands = new String[]{javaCmd, classPath, startClass}; String commandString = StringUtils.join(commands, " "); Process process = Runtime.getRuntime().exec(commandString); So, how should I setup the classpath? Thanks for any help

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  • Only show content when certain criteria is met?

    - by Elliot
    I'm wondering if theres a best practice for what I'm trying to accomplish... First we have the model categories, categories, has_many posts. Now lets say, users add posts. Now, I have a page, that I want to display only the current user's posts by category. Lets say we have the following categories: A, B, and C User 1, has posted in Categories A and B. In my view I have something like: @categories.each do |category| category.name @posts.each do |post| if post.category_id==category.id post content here end end end The problem with this, is I'm going to show the empty category, as well as the categories that do have content. Is there a more efficient way of going about this? As I don't want to show the empty categories. Best, Elliot

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  • Navigate to the Same Page After Action in JSF 2

    - by shipmaster
    I have a component done in JSF 1.x, this component has a command button as follows <h:commandButton ... action="#{templateController.next}" /> Where templateController was passed as an EL binding and can be any object that implements a certain interface. The generic implementation of next() was just executing code and then returning an empty string causing the same page to refresh: public String next() { ..... return ""; } Now I am trying to port that component to JSF 2, my problem is that an empty string doesn't cause the same page to refresh anymore, instead, the framework tries to redirect to a page called ".jsf" i.e it just appends .jsf to whatever the outcome is. My question is how to return an outcome that causes the current page to refresh. My component is generic and I don't know before hand the name of the page it is going to be used on. Thanks

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  • C# can I lock a method parameter?

    - by 5YrsLaterDBA
    We have a class variable ArrayList binaryScanData in a class. In all methods having access to it, we put lock(binaryScanData) on it because it is shared. Now we want to move one of those methods out to another util class to make it a static method. We will pass that binaryScanData into the method like this: public static void convertAndSaveRawData(ref MemoryStream output, ref ArrayList binaryScanData) Our questions are followed: how can we sychoronize that binaryScanData? can we do the same as it is originally? ref is necessary? It will only be read in that convertAndSaveRawData method.

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  • Integrate flex 3.5 projects in flash builder 4 beta 2

    - by Cyrill Zadra
    Hi I'm currently using Flex Builder 3 and Flex SDK 3.5 for my projects. But I'd like to try out the new Flash Builder 4. So I downloaded and installed the new software, configured all the additional software like subversion, server adapter .. and finally a importet my 2 projects. 1) Main Project (includes a swc generated by the Library Project) (flex sdk 3.5) 2) Library Project (flex sdk 3.4) After the import and project cleanup the project is running perfectly. But as soon as I replace the existing LibraryProject.swc through a new one (compiled with flash builder 4 beta 2 sdk 3.4) VerifyError: Error #1014: class mx.containers::Canvas not found. VerifyError: Error #1014: class mx.containers::HBox not found. VerifyError: Error #1014: class IWatcherSetupUtil not found. ... and several others not found errors. Does anyone has the same error. How can I get my project running again? thanks & regards cyrill

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  • Using CSS Classes for indivdual effects - opinions?

    - by Cool Hand Luke UK
    Hey, Just trying to canvas some opinions here. I was wondering how people go about adding individual effects to html elements. Take this example: you have three types of h1 titles all the same size but some are black some are gold and some are white. Some have a text-shadow etc. Would you create separate CSS classes and add them do the h1 tag or would you create a new single class for each different h1 title type (with grouped CSS elements)? With singular class for each effect you can build up combos of classes in html class="gold shadow" but also how would you name them. For example its bad practice to give classes and id names associated to colours, because it doesn't define what it does well. However is this ok with textual CSS classes? Just wondering what others do, I know there are no hard and fast rules. Cheers.

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  • Why can't I declare C# methods virtual and static?

    - by Luke
    I have a helper class that is just a bunch of static methods and would like to subclass the helper class. Some behavior is unique depending on the subclass so I would like to call a virtual method from the base class, but since all the methods are static I can't create a plain virtual method (need object reference in order to access virtual method). Is there any way around this? I guess I could use a singleton.. HelperClass.Instance.HelperMethod() isn't so much worse than HelperClass.HelperMethod(). Brownie points for anyone that can point out some languages that support virtual static methods. Edit: OK yeah I'm crazy. Google search results had me thinking I wasn't for a bit there.

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  • Grails: Problem with nested associations in criteria builder

    - by Mr.B
    I have a frustrating problem with the criteria builder. I have an application in which one user has one calendar, and a calendar has many entries. Seems straightforward enough, but when I try to get the calendar entries for a given user, I can't access the user property (MissingMethodException). Here's the code: def getEntries(User user) { def entries = Entries.createCriteria().list() { calendar { user { eq("user.id", user.id) } } } } I have even tried the following variation: def getEntries(User user) { def entries = Entries.createCriteria().list() { calendar { eq("user", user) } } } That did not raise an exception, but didn't work either. Here's the relevant parts of the domain classes: class Calendar { static belongsTo = [user: User] static hasMany = [entries: Entries] ... } class User { Calendar calendar ... } class Entry { static belongsTo = [calendar: Calendar] ... } When Googling I came across a similar problem noted in early 2008: http://jira.codehaus.org/browse/GRAILS-1412 But according to that link this issue should have been solved long ago. What am I doing wrong?

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  • hyperLink on jsf error messages problem

    - by user234194
    I am trying to put link in the error messages produced by JSF. For this I am using the custom renderer, it works(clicking the error, focuses the respective input field) but the problem is , all the form values gets empty. ie when error occurs, all the input fields get empty. Any suggestion will be appreciated. package custom; public class CustomErrorRenderer extends Renderer { @Override @SuppressWarnings("unchecked") public void encodeEnd(FacesContext context, UIComponent component) throws IOException { ResponseWriter writer = context.getResponseWriter(); writer.startElement("div", component); writer.writeAttribute("id", component.getClientId(context), "id"); writer.writeAttribute("style", "color: red", null); writer.startElement("ul", null); Iterator clientIds = context.getClientIdsWithMessages(); while (clientIds.hasNext()) { String clientId = clientIds.next(); Iterator messages = context.getMessages(clientId); if (!messages.hasNext()) { continue; } String javaScript = "var field = document.getElementById('" + clientId + "');" + "if(field == null) return false;" + "field.focus(); return false;"; writer.startElement("li", null); writer.startElement("a", null); writer.writeAttribute("onclick", javaScript, null); writer.writeAttribute("href", "#", null); while (messages.hasNext()) { writer.writeText(messages.next().getSummary(), null); } writer.endElement("a"); writer.endElement("li"); } writer.endElement("ul"); writer.endElement("div"); } } This renderer is defined in faces-config.xml: add to base HTML_BASIC renderkit HTML_BASIC HTML_BASIC CustomErrorRenderer javax.faces.Output custom.CustomErrorRenderer custom.CustomErrorRenderer CustomErrorMessages custom.Errors javax.faces.component.UIOutput a tag class: package custom; import javax.faces.webapp.UIComponentELTag; public class CustomErrorTag extends UIComponentELTag { @Override public String getComponentType() { return "custom.Errors"; } @Override public String getRendererType() { return "custom.CustomErrorRenderer"; } } This is defined in a TLD file: http://java.sun.com/xml/ns/javaee/web-jsptaglibrary_2_1.xsd" version="2.1" 1.0 custom http://custom errors custom.CustomErrorTag empty This goes at the top of the JSP page: <%@ taglib prefix="custom" uri="http://custom"%

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  • Ajax/PHP contact form not able to send mail

    - by Steph
    The funny thing is it did work for one evening. I contacted my host, and they are saying there's no reason it should not be working. I have also attempted to test it in Firebug, but it seemed to be sending. And I specifically put the email address (hosted in my domain) on my email safe list, so that is not the culprit either. Would anyone here take a look at it for me? I'd be so grateful. In the header I have: <script type="text/javascript"> $(document).ready(function() { var options = { target: '#alert' }; $('#contactForm').ajaxForm(options); }); $.fn.clearForm = function() { return this.each(function() { var type = this.type, tag = this.tagName.toLowerCase(); if (tag == 'form') return $(':input',this).clearForm(); if (type == 'text' || type == 'password' || tag == 'textarea') this.value = ''; else if (type == 'checkbox' || type == 'radio') this.checked = false; else if (tag == 'select') this.selectedIndex = -1; }); }; </script> Here is the actual form: <form id="contactForm" method="post" action="sendmail.php"> <fieldset> <p>Email Me</p> <div id="fieldset_container"> <label for="name">Your Name:</label> <input type="text" name="name" id="name" /><br /><br /> <label for="email">Email:</label> <input type="text" name="email" id="email" /><br /><br /> <span style="display:none;"> <label for="last">Honeypot:</label> <input type="text" name="last" value="" id="last" /> </span><br /><br /> <label for="message">Comments &amp; Inquiries:</label> <textarea name="message" id="message" cols="" rows=""></textarea><br/> </div> <div id="submit_button"> <input type="submit" name="submit" id="submit" value="Send It" /> </div> </fieldset> </form> <div class="message"><div id="alert"></div></div> Here is the code from my validating page, sendmail.php: <?php // Who you want to recieve the emails from the form. (Hint: generally you.) $sendto = '[email protected]'; // The subject you'll see in your inbox $subject = 'SH Contact Form'; // Message for the user when he/she doesn't fill in the form correctly. $errormessage = 'There seems to have been a problem. May I suggest...'; // Message for the user when he/she fills in the form correctly. $thanks = "Thanks for the email!"; // Message for the bot when it fills in in at all. $honeypot = "You filled in the honeypot! If you're human, try again!"; // Various messages displayed when the fields are empty. $emptyname = 'Entering your name?'; $emptyemail = 'Entering your email address?'; $emptymessage = 'Entering a message?'; // Various messages displayed when the fields are incorrectly formatted. $alertname = 'Entering your name using only the standard alphabet?'; $alertemail = 'Entering your email in this format: <i>[email protected]</i>?'; $alertmessage = "Making sure you aren't using any parenthesis or other escaping characters in the message? Most URLS are fine though!"; //Setting used variables. $alert = ''; $pass = 0; // Sanitizing the data, kind of done via error messages first. Twice is better! ;-) function clean_var($variable) { $variable = strip_tags(stripslashes(trim(rtrim($variable)))); return $variable; } //The first if for honeypot. if ( empty($_REQUEST['last']) ) { // A bunch of if's for all the fields and the error messages. if ( empty($_REQUEST['name']) ) { $pass = 1; $alert .= "<li>" . $emptyname . "</li>"; } elseif ( ereg( "[][{}()*+?.\\^$|]", $_REQUEST['name'] ) ) { $pass = 1; $alert .= "<li>" . $alertname . "</li>"; } if ( empty($_REQUEST['email']) ) { $pass = 1; $alert .= "<li>" . $emptyemail . "</li>"; } elseif ( !eregi("^[_a-z0-9-]+(.[_a-z0-9-]+)*@[a-z0-9-]+(.[a-z0-9-]+)*(.[a-z]{2,3})$", $_REQUEST['email']) ) { $pass = 1; $alert .= "<li>" . $alertemail . "</li>"; } if ( empty($_REQUEST['message']) ) { $pass = 1; $alert .= "<li>" . $emptymessage . "</li>"; } elseif ( ereg( "[][{}()*+?\\^$|]", $_REQUEST['message'] ) ) { $pass = 1; $alert .= "<li>" . $alertmessage . "</li>"; } //If the user err'd, print the error messages. if ( $pass==1 ) { //This first line is for ajax/javascript, comment it or delete it if this isn't your cup o' tea. echo "<script>$(\".message\").hide(\"slow\").show(\"slow\"); </script>"; echo "<b>" . $errormessage . "</b>"; echo "<ul>"; echo $alert; echo "</ul>"; // If the user didn't err and there is in fact a message, time to email it. } elseif (isset($_REQUEST['message'])) { //Construct the message. $message = "From: " . clean_var($_REQUEST['name']) . "\n"; $message .= "Email: " . clean_var($_REQUEST['email']) . "\n"; $message .= "Message: \n" . clean_var($_REQUEST['message']); $header = 'From:'. clean_var($_REQUEST['email']); //Mail the message - for production mail($sendto, $subject, $message, $header, "[email protected]"); //This is for javascript, echo "<script>$(\".message\").hide(\"slow\").show(\"slow\").animate({opacity: 1.0}, 4000).hide(\"slow\"); $(':input').clearForm() </script>"; echo $thanks; die(); //Echo the email message - for development echo "<br/><br/>" . $message; } //If honeypot is filled, trigger the message that bot likely won't see. } else { echo "<script>$(\".message\").hide(\"slow\").show(\"slow\"); </script>"; echo $honeypot; } ?>

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  • C# Object Creation from Datatable

    - by Jonesy
    Hi Folks, Im just getting my head round C#. I've been creating classes and objects so say i created a class called Member: public class Member { public int MemberID; public string FirstName; public string LastName; public string UserName; } and i create a new object of that class by doing this: Member Billy = new Member(); Billy.UserName = "Jonesy"; Billy.FirstName = "Billy"; Billy.LastName = "Jones"; Thats all fine but what if I've queried a database and gotten back 5 members, can I create objects on the fly? Or what is the best way to store these members in memory? I've used VB.Net where I would just add them into a datatable. But I've never really done any object-oriented programming before and thought since I'm learning C sharp nows the best time to learn OOP.. Any help most appreciated! Jonesy

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  • Visualforce dataTable: is there a way to stop it from rendering cellpadding attribute?

    - by codeulike
    In Visualforce, I'm using an <apex:dataTable> component as follows: <apex:dataTable value="{!Qualifications}" var="qual" styleClass="cv_table" > <!-- etc... --> ... and then I'm using CSS to style the table, via the class name. Trouble is, VisualForce renders HTML like this: <table class="cv_table" id="j_id0:j_id26" border="0" cellpadding="0" cellspacing="0"> <!-- etc... --> The class attribute is there as I wanted, but there's also cellpadding and cellspacing specified, that interfere with my CSS. Is there a way to stop Visualforce from rendering the cellpadding and cellspacing attributes for an <apex:dataTable>?

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  • How do I get the java.concurrency.CyclicBarrier to work as expected

    - by Ritesh M Nayak
    I am writing code that will spawn two thread and then wait for them to sync up using the CyclicBarrier class. Problem is that the cyclic barrier isn't working as expected and the main thread doesnt wait for the individual threads to finish. Here's how my code looks: class mythread extends Thread{ CyclicBarrier barrier; public mythread(CyclicBarrier barrier) { this.barrier = barrier; } public void run(){ barrier.await(); } } class MainClass{ public void spawnAndWait(){ CyclicBarrier barrier = new CyclicBarrier(2); mythread thread1 = new mythread(barrier).start(); mythread thread2 = new mythread(barrier).start(); System.out.println("Should wait till both threads finish executing before printing this"); } } Any idea what I am doing wrong? Or is there a better way to write these barrier synchronization methods? Please help.

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  • Question about Jboss deployment

    - by Manoj
    Hi All, I am new to Jboss and deployment of web applications etc. I have two different war files deployed on the same Jboss server. Further they also share some classes which read different properties based on the application settings (Let's call a common class as CommonClass.class which is present in App1.war and App2.war; CommonClass has a member "FIELD1", so both these war files have CommonClass.class each of which reads different properties, into CommonClass.FIELD1). But during run-time when I access FIELD1 in one application (App2.war-CommonClass.FIELD1) it has the value from another application (App1.war-CommonClass.FIELD1). Is there any way I can explicitly specify so that JBoss treats these classes and fields to be different? so that both these classes can exist in memory yet hold their respective correct values? Thanks a ton, Manoj

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  • Jruby embedded modules and classes.

    - by James Moore
    Hey, I have a ruby file as follows: module Example class Myclass def t_st "Hello World!" end end end now if this was just a class I would be able to use the following java code: ScriptEngine jruby = new ScriptEngineManager().getEngineByName("jruby"); jruby.eval(new BufferedReader(new FileReader("example.rb"))); Object example = jruby.eval("myclass.new"); However, this class rests inside a module. Calling the same code as above produces the error: Exception in thread "main" org.jruby.embed.EvalFailedException: uninitialized constant myclass In addition, calling: Object example = jruby.eval("Example"); The module returns no error. So one would assume this follows the format for Ruby. Object example = jruby.eval("Example::myclass.new"); Again however, I get the same error as before. Can anyone help? As there is little documentation on JRuby? Thanks

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  • Django aggregation query on related one-to-many objects

    - by parxier
    Here is my simplified model: class Item(models.Model): pass class TrackingPoint(models.Model): item = models.ForeignKey(Item) created = models.DateField() data = models.IntegerField() In many parts of my application I need to retrieve a set of Item's and annotate each item with data field from latest TrackingPoint from each item ordered by created field. For example, instance i1 of class Item has 3 TrackingPoint's: tp1 = TrackingPoint(item=i1, created=date(2010,5,15), data=23) tp2 = TrackingPoint(item=i1, created=date(2010,5,14), data=21) tp3 = TrackingPoint(item=i1, created=date(2010,5,12), data=120) I need a query to retrieve i1 instance annotated with tp1.data field value as tp1 is the latest tracking point ordered by created field. That query should also return Item's that don't have any TrackingPoint's at all. If possible I prefer not to use QuerySet's extra method to do this. That's what I tried so far... and failed :( Item.objects.annotate(max_created=Max('trackingpoint__created'), data=Avg('trackingpoint__data')).filter(trackingpoint__created=F('max_created')) Any ideas?

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  • Javascript incapable of getting element's max-height via element.style.maxHeight

    - by Zane
    I am making a simple accordion menu in javascript. I'd like to be able to set the compact and expanded heights for the elements via the css max-height and min-height values. For some reason, when I try to retrieve the min-height and max-height of the elements in javascript for animation purposes, I get an empty string rather than, for instance, "500px" like it should. The max-height value is set in css, e.g. #id { min-height: 40px; max-height: 500px; } is all set up, but when I put a debugging mechanism in my javascript such as alert( item.style.minHeight ); it pops up an empty alert box. This happens in Firefox 3.6.2 and IE 8. Does anybody know why javascript refuses to be able to get an element's minHeight and maxHeight?

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  • SessionFactory in Hibernate

    - by komal
    Hi, I am using hibernate-2.1 and "net.sf.hibernate.SessionFactory" class in my spring project. Now I am switched to Spring 2.5.6.A, where they are using hibernate3 and I am not able to find out the "net.sf.hibernate" package in that. But I found SessionFactory class in the package "org.springframework.orm.toplink". Is both the class one in hibernate-2.1 "net.sf.hibernate.SessionFactory" and another in "org.springframework.orm.toplink.SessionFactory" are same? Can I replace first with second one? Thanks, Komal

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  • Convert/Cast base type to Derived type

    - by user102533
    I am extending the existing .NET framework class by deriving it. How do I convert an object of base type to derived type? public class Results { //Framework methods } public class MyResults : Results { //Nothing here } //I call the framework method public static MyResults GetResults() { Results results = new Results(); //Results results = new MyResults(); //tried this as well. results = CallFrameworkMethod(); return (MyResults)results; //Throws runtime exception } I understand that this happens as I am trying to cast a base type to a derived type and if derived type has additional properties, then the memory is not allocated. When I do add the additional properties, I don't care if they are initialized to null. How do I do this without doing a manual copy?

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  • Where is the virtual function call overhead?

    - by Semen Semenych
    Hello everybody, I'm trying to benchmark the difference between a function pointer call and a virtual function call. To do this, I have written two pieces of code, that do the same mathematical computation over an array. One variant uses an array of pointers to functions and calls those in a loop. The other variant uses an array of pointers to a base class and calls its virtual function, which is overloaded in the derived classes to do absolutely the same thing as the functions in the first variant. Then I print the time elapsed and use a simple shell script to run the benchmark many times and compute the average run time. Here is the code: #include <iostream> #include <cstdlib> #include <ctime> #include <cmath> using namespace std; long long timespecDiff(struct timespec *timeA_p, struct timespec *timeB_p) { return ((timeA_p->tv_sec * 1000000000) + timeA_p->tv_nsec) - ((timeB_p->tv_sec * 1000000000) + timeB_p->tv_nsec); } void function_not( double *d ) { *d = sin(*d); } void function_and( double *d ) { *d = cos(*d); } void function_or( double *d ) { *d = tan(*d); } void function_xor( double *d ) { *d = sqrt(*d); } void ( * const function_table[4] )( double* ) = { &function_not, &function_and, &function_or, &function_xor }; int main(void) { srand(time(0)); void ( * index_array[100000] )( double * ); double array[100000]; for ( long int i = 0; i < 100000; ++i ) { index_array[i] = function_table[ rand() % 4 ]; array[i] = ( double )( rand() / 1000 ); } struct timespec start, end; clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &start); for ( long int i = 0; i < 100000; ++i ) { index_array[i]( &array[i] ); } clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &end); unsigned long long time_elapsed = timespecDiff(&end, &start); cout << time_elapsed / 1000000000.0 << endl; } and here is the virtual function variant: #include <iostream> #include <cstdlib> #include <ctime> #include <cmath> using namespace std; long long timespecDiff(struct timespec *timeA_p, struct timespec *timeB_p) { return ((timeA_p->tv_sec * 1000000000) + timeA_p->tv_nsec) - ((timeB_p->tv_sec * 1000000000) + timeB_p->tv_nsec); } class A { public: virtual void calculate( double *i ) = 0; }; class A1 : public A { public: void calculate( double *i ) { *i = sin(*i); } }; class A2 : public A { public: void calculate( double *i ) { *i = cos(*i); } }; class A3 : public A { public: void calculate( double *i ) { *i = tan(*i); } }; class A4 : public A { public: void calculate( double *i ) { *i = sqrt(*i); } }; int main(void) { srand(time(0)); A *base[100000]; double array[100000]; for ( long int i = 0; i < 100000; ++i ) { array[i] = ( double )( rand() / 1000 ); switch ( rand() % 4 ) { case 0: base[i] = new A1(); break; case 1: base[i] = new A2(); break; case 2: base[i] = new A3(); break; case 3: base[i] = new A4(); break; } } struct timespec start, end; clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &start); for ( int i = 0; i < 100000; ++i ) { base[i]->calculate( &array[i] ); } clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &end); unsigned long long time_elapsed = timespecDiff(&end, &start); cout << time_elapsed / 1000000000.0 << endl; } My system is LInux, Fedora 13, gcc 4.4.2. The code is compiled it with g++ -O3. The first one is test1, the second is test2. Now I see this in console: [Ignat@localhost circuit_testing]$ ./test2 && ./test2 0.0153142 0.0153166 Well, more or less, I think. And then, this: [Ignat@localhost circuit_testing]$ ./test2 && ./test2 0.01531 0.0152476 Where are the 25% which should be visible? How can the first executable be even slower than the second one? I'm asking this because I'm doing a project which involves calling a lot of small functions in a row like this in order to compute the values of an array, and the code I've inherited does a very complex manipulation to avoid the virtual function call overhead. Now where is this famous call overhead?

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  • Use method not defined in Interface [Java]

    - by Samuel
    Hello World, I have an assignment and i got a library including an interface class. [InfoItem] I implement this class [Item]. Now i am required to write a method watchProgram(InfoItem item) [other class, importing InfoItem], which (as shown) requires an InfoItem. The passed parameter item has a variable 'Recorded' [boolean] which i want to edit using a method changeRecorded() that i defined in the implementation of InfoItem. I cannot edit the interface and i get an error message that the method is not found [cannot find symbol].. Any hints, suggestions, solutions? Thanks!! -Samuel-

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  • jQuery lava-lamp-like effect bouncing all over the place!

    - by Nathan Loding
    I followed the tutorial found here and added my own flare to it: tutorial What I was looking to accomplish was to put a specific image on the left and right side of the list item. So instead of just the generic <li id="blob"></li> created in the tutorial, I did <li id="blob"><div class="blob-wrap"><div class="leftimage"></div><div class="rightimage"></div></li> to accomplish the particular effect I wanted. It works beautifully ... except that the image attempts to bounce back the "currentPageItem" if I leave the mouse hovering over one of the list items. Here's a JS Bin example: http://jsbin.com/odome What do I need to do to fix it? jQuery is firing the "hoverOut" function (or whatever you want to call it). But why?

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