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  • Django: getting the list of related records for a list of objects

    - by Silver Light
    Hello! I have two models related one-to many: class Person(models.Model): name = models.CharField(max_length=255); surname = models.CharField(max_length=255); age = models.IntegerField(); class Dog(models.Model): name = models.CharField(max_length=255); owner = models.ForeignKey('Person'); I want to output a list of persons below each person a list of dogs he has. Here's how I can do it: in view: persons = Person.objects.all()[0:100]; in template: {% for p in persons %} {{ p.name }} has dogs:<br /> {% for d in persons.dog_set.all %} - {{ d.name }}<br /> {% endfor %} {% endfor %} But if I do it like that, Django will execute 101 SQL queries which is very inefficient. I tried to make a custom manager, which will get all the persons, then all the dogs and links them in python, but then I can't use paginator (my another question: http://stackoverflow.com/questions/2532475/django-paginator-raw-sql-query ) and it looks quite ugly. Is there a more graceful way doing this?

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  • How to strongly type properties in JavaScript that map to models in C# ?

    - by Roberto Sebestyen
    I'm not even sure if I worded the question right, but I'll try and explain as clearly as possible with an example: In the following example scenario: 1) Take a class such as this: public class foo { public string firstName {get;set;} public string lastName {get;set} } 2) Serialize that into JSON, pass it over the wire to the Browser. 3) Browser de-serializes this and turns the JSON into a JavaScript object so that you can then access the properties like this: var foo = deSerialize("*******the JSON from above**************"); alert(foo.firstName); alert(foo.lastName); What if now a new developer comes along working on this project decides that firstName is no longer a suitable property name. Lets say they use ReSharper to rename this property, since ReSharper does a pretty good job at finding (almost) all the references to the property and renaming them appropriately. However ReSharper will not be able to rename the references within the JavaScript code (#3) since it has no way of knowing that these also really mean the same thing. Which means the programmer is left with the responsibility of manually finding these references and renaming those too. The risk is that if this is forgotten, no one will know about this error until someone tests that part of the code, or worse, slip through to the customer. Back to the actual question: I have been trying to think of a solution to this to some how strongly type these property names when used in javascript, so that a tool like ReSharper can successfully rename ALL usages of the property? Here is what I have been thinking for example (This would obviously not work unless i make some kind of static properties) var foo = deSerialize("*******the JSON from above**************"); alert(foo.<%=foo.firstName.GetPropertyName()%>) alert(foo.<%=foo.lastName.GetPropertyName()%>) But that is obviously not practical. Does anyone have any thoughts on this? Thanks, and kudos to all of the talented people answering questions on this site.

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  • Image sprite not lining up in firefox

    - by Saif Bechan
    I am working with an image sprite to create my buttons. They work right in every browser except firefox. Lets say i have 2 spans next to eachother: <span class="spanleft"></span><span class="spanright"></span> and give them some styling(this is the actual code i use for the sprite) .spanleft{ background:url('/templates/default/img/auction/btn-toolbar.png') no-repeat 0 0; display:block; float:left; height:100px; width:13px; } .spanright{ background:url('/templates/default/img/auction/btn-toolbar.png') no-repeat 0 -104px; display:block; float:left; height:100px; width:30px; margin-left:0px; } Now this works in every browser i tested, the images line up great. But in firefox I get a small offset. Now i fiddled with the pixels a lot. Its not an offset of 1px, the offset is about 0.5 of a px. yeah. Ive made a screenshot of what i mean, and i'm going to put in the sprite for the buttons, they make lovely buttons, upstate,downstate,hover,disabled. You can use them in your projects. Here are the shots: This is the problem: Here is the image sprite: I hop this problem can be solved, i am working with FF 3.6. thanks guys!

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  • Performing an action on Parent/Child elements independently.

    - by Matt Weldon
    I have HTML similar to the following in my page <div id="someDiv"> <img src="foo.gif" class="someImg" /> </div> The wrapper div is set up such that when it is clicked, it's background-color changes using the following jQuery code. $("div").click(function(event){ $(this).css("background-color", "blue"); }); I also have some jQuery associated with my img that will do some other function (for the sake of argument I am going to display and alert box) like so: $("img[class=someImg]").click(function(event){ alert("Image clicked"); }); The issue I have come across is that when I click on the img, the event associated with the div is also triggered. I'm pretty sure that this is due to the way that jQuery (or indeed JavaScript) is handling the two DOM elements - clicking the img would require you to also technically click the div, thus triggering both events. Two questions then really: Is my understanding of the DOM/JavaScript flawed in some way or is this actually how things are occurring? Are there any jQuery methods that would allow me to perform actions on a child element without invoking those associated with its parent?

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  • Getting information from servlet created html

    - by user541597
    I have a servlet that creates an html text box and then redirects to another servlet on submit. How can I access the value of the html text box from the new servlet? I am able to access servlet variables from the new servlet but I am not aware of how to access the value of the html generated code. thanks, Here is the servlet that gets the text input public class ServletB extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { response.setContentType("text/html"); String value = System.getProperty("card"); PrintWriter out = response.getWriter(); out.println("<center><h1>Your preffered method of payment is "+value+"</h1><br />"); out.println("Please Enter Card Number<input type =\"text\" name = \"number\"/><form action=\"http://codd.cs.gsu.edu:9999/cpereyra183/servlet/ServletC\"><input type =\"submit\" value=\"Continue\" /><input type=\"button\" value=\"Cancel\" /></center>"); } }} This is the servlet the first servlet redirects to all I do is try to do is output the text input public class ServletC extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { response.setContentType("text/html"); String value = System.getProperty("card"); PrintWriter out = response.getWriter(); out.println(request.getParameter("number")); } }

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  • Logging in with sha1() encryption.

    - by Samir Ghobril
    Hey guys, I added this to my sign up code : $password=mysql_real_escape_string(sha1($_POST['password'])); and now it inserts the password into the database while its encrypted. But signing in doesn't seem to work anymore. Here is the login code. function checklogin($username, $password){ global $mysqli; $password=sha1($password); $result = $mysqli->prepare("SELECT * FROM users WHERE username = ? and password=?"); $result->bind_param("ss", $username, $password); $result->execute(); if($result != false){ $dbArray=$result->fetch(); if(!$dbArray){ echo '<p class="statusmsg">The username or password you entered is incorrect, or you haven\'t yet activated your account. Please try again.</p><br/><input class="submitButton" type="button" value="Retry" onClick="location.href='."'login.php'\">"; return; } $_SESSION['username']=$username; if(isset($_POST['remember'])){ setcookie("jmuser",$username,time()+60*60*24*356); setcookie("jmpass",$password ,time()+60*60*24*356); } redirect(); }

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  • javascript created input[type="text'] doesn't post it's variable

    - by ivannovak
    hey there, I'm creating a series of input elements and for some reason their values aren't $_POSTing. Any light shed on the subject would be appreciated! My current code is as follows: javascript Afields = 1; function addAdultInput() { if (Afields != 10) { document.getElementById('adultMembers').innerHTML += "<input type='text' value='' name='adult_members_"+Afields+"' /><br />"; Afields += 1; } else { document.getElementById('adultMembers').innerHTML += "Only 10 Adult Member fields allowed."; document.getElementById('addAdultMember').disabled=true; } } HTML <form name="form1" method="post" action=""> <tr> <td class="style12" valign="top">Adult Members' Names:<br /><small>10 Max </small><input id="addAdultMember" type="button" onclick="addAdultInput()" name="add" value="Add Adult" /></td> <td id="adultMembers"> <span class="erorr">*for paid members only</span><br /> <input type='text' value='' name='adult_members_0' /><br /> </td> </tr> <input type="submit" name="Submit" value="Register"> </form>

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  • why this code not works?

    - by badgirl
    Hello. I want to create new node of BeanTreeView, and when I add some node in constructor, then run the app, and then I try to view the window with tree, it throws this error java.lang.AssertionError: Component cannot be created for {component=null, displayName=Exploirer, instanceCreate=AlwaysEnabledAction[Exploirer]} at org.openide.windows.OpenComponentAction.getTopComponent(OpenComponentAction.java:71) Why? And how to add node there? See the code. private ProjectsChildren projectsChildren; private ProjectNode projectNode = new ProjectNode(new MainProject("ggg"), projectsChildren); public ExploirerTopComponent() { initComponents(); setName(NbBundle.getMessage(ExploirerTopComponent.class, "CTL_ExploirerTopComponent")); setToolTipText(NbBundle.getMessage(ExploirerTopComponent.class, "HINT_ExploirerTopComponent")); // setIcon(ImageUtilities.loadImage(ICON_PATH, true)); //map.put("delete", ExplorerUtils.actionDelete(mgr, true)); associateLookup (ExplorerUtils.createLookup(mgr, getActionMap())); //projectsChildren.createProject("demence"); /* somewhere here is the problem*/ mgr.setRootContext(projectNode); ProjectNode[] pr = null; pr[0] = projectNode; mgr.getRootContext().getChildren().add(pr); }

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  • Java JCheckBox ArrayList help needed

    - by user2929626
    I'm new to Java and struggling with something which I'm sure must have a simple answer but I can't seem to find it. I have an array of checkbox objects defined as: ArrayList<JCheckBox> checkBoxList A JPanel is created with a grid layout and the checkboxes are added to the JPanel and the ArrayList: for (int i = 0; i < 256; i++) { JCheckBox c = new JCheckBox(); c.setSelected(false); checkBoxList.add(c); mainPanel.add(c); } Yes, there are 256 checkboxes! The panel is added to a JFrame and eventually the GUI is displayed. The user can select any combination of the 256 checkboxes. My class implements Serializable and this ArrayList of checkboxes can be saved and restored using 'Save' and 'Load' GUI buttons. My code to load the saved object is as below: public class LoadListener implements ActionListener { public void actionPerformed(ActionEvent a) { try { // Prompt the user for a load file JFileChooser fileLoad = new JFileChooser(); fileLoad.showOpenDialog(mainFrame); // Create a object/file input stream linking to the selected file ObjectInputStream is = new ObjectInputStream(new FileInputStream(fileLoad.getSelectedFile())); // Read the checkBox array list checkBoxList = (ArrayList<JCheckBox>) is.readObject(); is.close(); } catch (Exception ex) { ex.printStackTrace(); } } On loading the ArrayList object, the values of the checkboxes are correctly populated, however I want to update the checkboxes on the GUI to reflect this. Is there an easy way to do this? I assumed as the array of checkboxes had the correct values that I could just repaint the panel / frame but this doesn't work. I'd like to understand why - does my loaded array of checkbox objects no longer reflect the checkbox objects on the GUI? Any help would be much appreciated. Thanks!

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  • Mechanize form submit not going to the correct response page, no errors as to why. Something I'm doing?

    - by Zack Shapiro
    I threw this all in one controller for testing purposes. My code fills out the form correctly for adding a new address to your Amazon account. There are two buttons that submit this form, one takes you to add a new address which is what I don't want, and the other is just a Save & Continue input/image. When I submit the form via that button, as I do below, the form is still on the page, filled out as I have with my code. Inspecting the page titles, they're the same. There are no discernible errors that Mechanize or Amazon spit back. Any ideas? class AmazonCrawler def initialize @agent = Mechanize.new do |agent| agent.user_agent_alias = 'Mac Safari' agent.follow_meta_refresh = true agent.redirect_ok = true end end def login # login_url = "https://www.amazon.com/ap/signin?_encoding=UTF8&openid.assoc_handle=usflex&openid.claimed_id=http%3A%2F%2Fspecs.openid.net%2Fauth%2F2.0%2Fidentifier_select&openid.identity=http%3A%2F%2Fspecs.openid.net%2Fauth%2F2.0%2Fidentifier_select&openid.mode=checkid_setup&openid.ns=http%3A%2F%2Fspecs.openid.net%2Fauth%2F2.0&openid.ns.pape=http%3A%2F%2Fspecs.openid.net%2Fextensions%2Fpape%2F1.0&openid.pape.max_auth_age=0&openid.return_to=https%3A%2F%2Fwww.amazon.com%2Fgp%2Fcss%2Fhomepage.html%3Fie%3DUTF8%26ref_%3Dgno_yam_ya" login_url = "https://www.amazon.com/gp/css/account/address/view.html?ie=UTF8&ref_=ya_add_address&viewID=newAddress" @agent.get(login_url) form = @agent.page.forms.first form.email = "[email protected]" form.radiobuttons.first.value = "0" form.radiobuttons.last.check form.password = "my_password" dashboard = @agent.submit(form) end end class UsersController < ApplicationController def index response = AmazonCrawler.new.login form = response.forms[1] # fill out form form.enterAddressFullName == "Your Name" form.enterAddressAddressLine1 = "123 Main Street" form.enterAddressAddressLine2 = "Apartment 34" form.enterAddressCity = "San Francisco" form.enterAddressStateOrRegion = "CA" form.enterAddressPostalCode = "94101" form.enterAddressPhoneNumber = "415-555-1212" form.AddressType = "RES" new_response = form.submit( form.button_with(value: /Save.*Continue/) ) end end

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  • Implementing deadlock condition

    - by Bhaskar
    I am trying to implementing deadlock condition but somehow I am not able to get it working. Both the threads Thread1 and Thread2 are entering in the run function but only one of them enters in Sub/Sum depending on who entered run first. Example : if Thread2 entered run first the it will call sub() and Thread1 never calls sum(). I have also added sleep time so that Thread2 sleeps before calling sum() and Thread1 gets enough time to enter Sum() but Thread1 never enters. public class ExploringThreads { public static void main(String[] args) { // TODO Auto-generated method stub threadexample a1 = new threadexample(); Thread t1 = new Thread(a1, "Thread1"); Thread t2 = new Thread(a1,"Thread2"); t1.start(); t2.start(); } } class threadexample implements Runnable{ public int a = 10; public void run(){ if(Thread.currentThread().getName().equals("Thread1")) sum(); else if(Thread.currentThread().getName().equals("Thread2")) sub(); } public synchronized void sum() { try { Thread.sleep(2000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println(Thread.currentThread().getName()+"In Sum"); sub(); } public synchronized void sub() { try { Thread.sleep(2000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println(Thread.currentThread().getName()+"In Sub"); sum(); } }

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  • Manually extracting portions of strings contained in a list (parsing)

    - by user1652011
    I'm aware that there are modules that fully simplify this function, but saying that I am running from a base install of python (standard modules only), how would I extract the following: I have a list. This list is the contents, line by line, of a webpage. Here is a mock up list (unformatted) for informative purposes: <script> link = "/scripts/playlists/1/" + a.id + "/0-5417069212.asx"; <script> "<a href="/apps/audio/?feedId=11065"><span class="px13">Eastern Metro Area Fire</span>" From the above string, I need the following extracted. The feedId (11065), which is incidentally a.id in the code above., "/scripts/playlists/1/" and "/0-5417069212.asx". Remembering that each of these lines is just contents from objects in a list, how would I go about extracting that data? Here is the full list: contents = urllib2.urlopen("http://www.radioreference.com/apps/audio/?ctid=5586") Pseudo: from urllib2 import urlopen as getpage page_contents = getpage("http://www.radioreference.com/apps/audio/?ctid=5586") feedID = % in (page_contents.search() for "/apps/audio/?feedId=%") titleID = % in (page_contents.search() for "<span class="px13">%</span>") playlistID = % in (page_contents.search() for "link = "%" + a.id + "*.asx";") asxID = * in (page_contents.search() for "link = "*" + a.id + "%.asx";") streamURL = "http://www.radioreference.com/" + playlistID + feedID + asxID + ".asx" I plan to format it as such that streamURL should = : http://www.radioreference.com/scripts/playlists/1/11065/0-5417067072.asx

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  • Serialization for memcached

    - by Ram
    I have this huge domain object(say parent) which contains other domain objects. It takes a lot of time to "create" this parent object by querying a DB (OK we are optimizing the DB). So we decided to cache it using memcached (with northscale to be specific) So I have gone through my code and marked all the classes (I think) as [Serializable], but when I add it to the cache, I see a Serialization Exception getting thrown in my VS.net output window. var cache = new NorthScaleClient("MyBucket"); cache.Store(StoreMode.Set, key, value); This is the exception: A first chance exception of type 'System.Runtime.Serialization.SerializationException' occurred in mscorlib.dll SO my guess is, I have not marked all classes as [Serializable]. I am not using any third party libraries and can mark any class as [Serializable], but how do I find out which class is failing when the cache is trying to serialize the object ? Edit1: casperOne comments make me think. I was able to cache these domain object with Microsoft Cache Application Block without marking them [Serializable], but not with NorthScale memcached. It makes me think that there might be something to do with their implementation, but just out of curiosity, am still interested in finding where it fails when trying to add the object to memcached

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  • implementing interface

    - by 1ace1
    hello guys so i have this assignment that i need to implement interface to go over an ArrayList and sort it (ascending or descnding).I dont want "the" answer i just need some suggestions on my approach and why i get this error Exception in thread "main" java.lang.ClassCastException: Week7.Check cannot be cast to java.lang.Comparable at java.util.Arrays.mergeSort(Unknown Source) at java.util.Arrays.sort(Unknown Source) at java.util.Collections.sort(Unknown Source) at Week7.TestCheck.main(TestCheck.java:18) This is how i did it: comparable had one method called public int compairTo(Object o) public class Check implements comparable { private Integer checkNumber; public Check(Integer newCheckNumber) { setCheckNumber(newCheckNumber); } public String toString() { return getCheckNumber().toString(); } public void setCheckNumber(Integer checkNumber) { this.checkNumber = checkNumber; } public Integer getCheckNumber() { return checkNumber; } @Override public int compairTo(Object o) { Check compair = (Check)o; int result = 0; if (this.getCheckNumber() > compair.getCheckNumber()) result = 1; else if(this.getCheckNumber() < compair.getCheckNumber()) result = -1; return result; } } in my main i had this import java.util.ArrayList; import java.util.Collections; public class TestCheck { public static void main(String[] args) { ArrayList checkList = new ArrayList(); checkList.add(new Check(445)); checkList.add(new Check(101)); checkList.add(new Check(110)); checkList.add(new Check(553)); checkList.add(new Check(123)); Collections.sort(checkList); for (int i =0; i < checkList.size(); i++){ System.out.println(checkList.get(i)); } } }

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  • Switching between 2 UINavigationControllers

    - by Smikey
    Hi all, I seem to have a problem switching between 2 UINavigationControllers, i.e. one which controls the main (selection) menu of my application, and the second which controls the main session (i.e. the user can't go back to the selection menu once they're started a new session). The first works just fine, but I get into trouble when trying to load the second. I have a class called GameViewController which contains the second UINavigationController instance. I set this up as usual, linking it as an IBOutlet to the delegate and setting up the NavController in the GameViewController.xib file with its 'Class' property pointing at GameScreenViewController (my main game screen), and its NIB Name property pointing to the GameScreenViewController nib file. I then create a new instance of GameViewController and load it. In IB, the navigation controller looks fine, with its View 'loaded from "GameScreenViewController"', however when the NavigationController is loaded in the game, it actually loads the GameViewController's UIWindow instance (just a blank window). I'm not sure how to make it load the Navigation Controller's view rather than its own window? Also, another quick question. When I load the second navigation controller from the first, which makes more sense to use: [self.view addSubview:gameViewController.view]; or [self presentModalViewController:gameViewController animated:YES]; Thanks for any help, much appreciated :D Michael

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  • NHibernate Entity code conversion from #C to VB.Net

    - by CoderRoller
    Hello and thanks for your help in advance. I am starting on the NHibernate world and i am experimenting with the NHibernate CookBook recipes, i am trying to set a base entity class for my entities and this is the C# code for this. I would like to know whats the VB.NET version so i can implement it in my sample project. This is the C# code: public abstract class Entity<TId> { public virtual TId Id { get; protected set; } public override bool Equals(object obj) { return Equals(obj as Entity<TId>); } private static bool IsTransient(Entity<TId> obj) { return obj != null && Equals(obj.Id, default(TId)); } private Type GetUnproxiedType() { return GetType(); } public virtual bool Equals(Entity<TId> other) { if (other == null) return false; if (ReferenceEquals(this, other)) return true; if (!IsTransient(this) && !IsTransient(other) && Equals(Id, other.Id)) { var otherType = other.GetUnproxiedType(); var thisType = GetUnproxiedType(); return thisType.IsAssignableFrom(otherType) || otherType.IsAssignableFrom(thisType); } return false; } public override int GetHashCode() { if (Equals(Id, default(TId))) return base.GetHashCode(); return Id.GetHashCode(); } } I tried using an online converter but puts a Nothing reference in place of default(TId) that doesn't seem right to me that's why I request for help: Private Shared Function IsTransient(obj As Entity(Of TId)) As Boolean Return obj IsNot Nothing AndAlso Equals(obj.Id, Nothing) End Function I Would appreciate the insight you may give me on the subject.

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  • HABTM selection seemingly ignores joinTable

    - by TheCapn
    I'm attempting to do a HABTM relationship between a Users table and Groups table. The problem is, that I when I issue this call: $this->User->Group->find('list'); The query that is issued is: SELECT [Group].[id] AS [Group__id], [Group].[name] AS [Group__name] FROM [groups] AS [Group] WHERE 1 = 1 I can only assume at this point that I have defined my relationship wrong as I would expect behavior to use the groups_users table that is defined on the database as per convention. My relationships: class User extends AppModel { var $name = 'User'; //...snip... var $hasAndBelongsToMany = array( 'Group' => array( 'className' => 'Group', 'foreignKey' => 'user_id', 'associationForeignKey' => 'group_id', 'joinTable' => 'groups_users', 'unique' => true, ) ); //...snip... } class Group extends AppModel { var $name = 'Group'; var $hasAndBelongsToMany = array ( 'User' => array( 'className' => 'User', 'foreignKey' => 'group_id', 'associationForeignKey' => 'user_id', 'joinTable' => 'groups_users', 'unique' => true, )); } Is my understanding of HABTM wrong? How would I implement this Many to Many relationship where I can use CakePHP to query the groups_users table such that a list of groups the currently authenticated user is associated with is returned?

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  • Java loop to collect the second and third elements every three in an array

    - by mhollander38
    I have a file with data in the form timestamp, coordinate, coordinate, seperated by spaces, as here; 14:25:01.215 370.0 333.0 I need to loop through and add the coordinates only to an array. The data from the file is read in and put into as String[] called info, from split(" "). I have two problems, I think the end of the file has a extra " " which I need to lose appropriately and I also want confirmation/suggestions of my loop, at the moment I am getting sporadic out of bounds exceptions. My loop is as follows; String[] info; info = dataHolder.split(" "); ArrayList<String> coOrds1 = new ArrayList<String>(); for (int counter = 0; counter < info.length; counter = counter+3) { coOrds1.add(info[counter+1]); coOrds1.add(info[counter+2]); } Help and suggestions appreciated. The text file is here but the class receives in a UDP packet from another class so I am unsure if this potentially adds " " at the end or not.

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  • How would i stop this foreach loop after 3 iterations?

    - by Tapha
    Here is the loop. foreach($results->results as $result){ echo '<div id="twitter_status">'; echo '<img src="'.$result->profile_image_url.'" class="twitter_image">'; $text_n = $result->text; echo "<div id='text_twit'>".$text_n."</div>"; echo '<div id="twitter_small">'; echo "<span id='link_user'".'<a href="http://www.twitter.com/'.$result->from_user.'">'.$result->from_user.'</a></span>'; $date = $result->created_at; $dateFormat = new DateIntervalFormat(); $time = strtotime($result->created_at); echo "<div class='time'>"; print sprintf('Submitted %s ago', $dateFormat->getInterval($time)); echo '</div>'; echo "</div>"; echo "</div>"; Thanks!!!! alot.

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  • IS operator behaving a bit strangely

    - by flockofcode
    1) According to my book, IS operator can check whether expression E (E is type) can be converted to the target type only if E is either a reference conversion, boxing or unboxing. Since in the following example IS doesn’t check for either of the three types of conversion, the code shouldn’t work, but it does: int i=100; if (i is long) //returns true, indicating that conversion is possible l = i; 2) a) B b; A a = new A(); if (a is B) b = (B)a; int i = b.l; class A { public int l = 100; } class B:A { } The above code always causes compile time error “Use of unassigned variable”. If condition a is B evaluates to false, then b won’t be assigned a value, but if condition is true, then it will. And thus by allowing such a code compiler would have no way of knowing whether the usage of b in code following the if statement is valid or not ( due to not knowing whether a is b evaluates to true or false) , but why should it know that? Intsead why couldn’t runtime handle this? b) But if instead we’re dealing with non reference types, then compiler doesn’t complain, even though the code is identical.Why? int i = 100; long l; if (i is long) l = i; thank you

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  • Design Pattern for Changing Object

    - by user210757
    Is there a Design Pattern for supporting different permutations object? Version 1 public class myOjbect { public string field1 { get; set; } /* requirements: max length 20 */ public int field2 { get; set; } . . . public decimal field200 { get; set; } } Version 2 public class myObject { public string field1 { get; set; } /* requirements: max length 40 */ public int field2 { get; set; } . . . public double field200 { get; set; } /* changed data types */ . . ./* 10 new properties */ public double field210 { get; set; } } of course I could just have separate objects, but thought there might be a good pattern for this sort of thing.

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  • Rails how to return a list of answers with a specific question_id

    - by mytwocentsisworthtwocents
    Let's say I have two Models, Answers and Questions (there are others, but irrelevant to the question). The models are as follows: Answer.rb class Answer < ActiveRecord::Base attr_accessible :description, :question_id has_one :question, :through => :user, :dependent => :destroy validates :description, :presence => true end Question.rb class Question < ActiveRecord::Base attr_accessible :budget, :description, :headline, :user_id, :updated_at, :created_at belongs_to :user has_many :answers validates :headline, :description, :user_id, :presence => true end I'd like to display on a page a list of all answers associated with a question, and only those questions. I got this far. I believe this variable finds all the questions in the database by the question_id (foreign key): @findanswers = Answer.all(params[:question_id]) And this one grabs the the id of the current question (this code will reside as an ERB on the page where the current question is located): @questionshow = Question.find(params[:id]) And now I'm stuck. How do I put the two together so that I list all the answers with the current question id?

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  • Attribute value nil

    - by mridula
    Can someone tell me why is this happening? I have created a social networking website using Ruby on Rails. This is my first time programming with RoR. I have a model named "Friendship" which contains an attribute "blocked" to indicate whether the user has blocked another user. When I run the following in IRB - friendship = u.friendships.where(:friend_id => 22).first IRB gives me - Friendship Load (0.6ms) SELECT `friendships`.* FROM `friendships` WHERE `friendships`.`user_id` = 17 AND `friendships`.`friend_id` = 22 LIMIT 1 => #<Friendship id: 33, user_id: 17, friend_id: 22, created_at: "2012-04-07 10:29:49", updated_at: "2012-04-07 10:29:49", blocked: 1> As u can see, the "blocked" attribute has value '1'. But when I run the following 1.9.2-p290 :030 > friendship.blocked => nil - it says, the value of blocked is 'nil' and not '1'. Why is this happening? This could be a very silly mistake but I am new to RoR, so kindly help me! I initially didn't include the accessor method for 'blocked'.. I tried that, and still its giving the same result.. Following is the Friendship model.. class Friendship < ActiveRecord::Base belongs_to :friend, :class_name => "User" validates_uniqueness_of :friend_id , :scope => :user_id attr_accessor :blocked attr_accessible :blocked end Here is the schema of the table: 1.9.2-p290 :009 > friendship.class => Friendship(id: integer, user_id: integer, friend_id: integer, created_at: datetime, updated_at: datetime, blocked: integer)

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  • Help me convert C# 1.1 Xml validation code to C# 2.0 please.

    - by Hamish Grubijan
    It would be fantastic if you could help me rid of these warnings below. I have not been able to find a good document. Since the warnings are concentrated in just the private void ValidateConfiguration( XmlNode section ) section, hopefully this is not terribly hard to answer, if you have encountered this before. Thanks! 'System.Configuration.ConfigurationException.ConfigurationException(string)' is obsolete: 'This class is obsolete, to create a new exception create a System.Configuration!System.Configuration.ConfigurationErrorsException' 'System.Xml.XmlValidatingReader' is obsolete: 'Use XmlReader created by XmlReader.Create() method using appropriate XmlReaderSettings instead. http://go.microsoft.com/fwlink/?linkid=14202' private void ValidateConfiguration( XmlNode section ) { // throw if there is no configuration node. if( null == section ) { throw new ConfigurationException("The configuration section passed within the ... class was null ... there must be a configuration file defined.", section ); } //Validate the document using a schema XmlValidatingReader vreader = new XmlValidatingReader( new XmlTextReader( new StringReader( section.OuterXml ) ) ); // open stream on Resources; the XSD is set as an "embedded resource" so Resource can open a stream on it using (Stream xsdFile = XYZ.GetStream("ABC.xsd")) using (StreamReader sr = new StreamReader(xsdFile)) { vreader.ValidationEventHandler += new ValidationEventHandler(ValidationCallBack); vreader.Schemas.Add(XmlSchema.Read(new XmlTextReader(sr), null)); vreader.ValidationType = ValidationType.Schema; // Validate the document while (vreader.Read()) { } if (!_isValidDocument) { _schemaErrors = _sb.ToString(); throw new ConfigurationException("XML Document not valid"); } } } // Does not cause warnings. private void ValidationCallBack( object sender, ValidationEventArgs args ) { // check what KIND of problem the schema validation reader has; // on FX 1.0, it gives a warning for "<xs:any...skip" sections. Don't worry about those, only set validation false // for real errors if( args.Severity == XmlSeverityType.Error ) { _isValidDocument = false; _sb.Append( args.Message + Environment.NewLine ); } }

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  • java.lang.NoClassDefFoundError thrown with my own packages in Android 1.5

    - by TiGer
    Hi, I have developed an application which has several packages within it's project... A class in one of those packages is called right away in the first line of code, which throws the dreaded java.lang.NoClassDefFoundError error... I don't get it, the package simply is within the project, and it works fine on my Android 1.6 device, but won't work with my 1.5 device... I do have to say that the project was originally set for 1.6, but then I changed the within the manifest from 4 to 3... Is that bad practice ? Or maybe it has nothing to do with the platform version ? Also I do get these lines as wel from the DDMS : 05-04 17:24:59.921: WARN/dalvikvm(2041): VFY: unable to resolve static field 2 (MANUFACTURER) in Landroid/os/Build; 05-04 17:24:59.921: WARN/dalvikvm(2041): VFY: rejecting opcode 0x62 at 0x0034 05-04 17:24:59.921: WARN/dalvikvm(2041): VFY: rejected Lmobilaria/android/managementModule/Management;.getDeviceSpecifics ()V 05-04 17:24:59.921: WARN/dalvikvm(2041): Verifier rejected class Lmobilaria/android/managementModule/Management; Thats the ManagementModule which also tries to retrieve several info-fields of the device itself... Again, this works just fine on the 1.6 device, even though thats a development device whilst my 1.5 device is a non-development device...

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