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  • Python: circular imports needed for type checking

    - by phild
    First of all: I do know that there are already many questions and answers to the topic of the circular imports. The answer is more or less: "Design your Module/Class structure properly and you will not need circular imports". That is true. I tried very hard to make a proper design for my current project, I in my opinion I was successful with this. But my specific problem is the following: I need a type check in a module that is already imported by the module containing the class to check against. But this throws an import error. Like so: foo.py: from bar import Bar class Foo(object): def __init__(self): self.__bar = Bar(self) bar.py: from foo import Foo class Bar(object): def __init__(self, arg_instance_of_foo): if not isinstance(arg_instance_of_foo, Foo): raise TypeError() Solution 1: If I modified it to check the type by a string comparison, it will work. But I dont really like this solution (string comparsion is rather expensive for a simple type check, and could get a problem when it comes to refactoring). bar_modified.py: from foo import Foo class Bar(object): def __init__(self, arg_instance_of_foo): if not arg_instance_of_foo.__class__.__name__ == "Foo": raise TypeError() Solution 2: I could also pack the two classes into one module. But my project has lots of different classes like the "Bar" example, and I want to seperate them into different module files. After my own 2 solutions are no option for me: Has anyone a nicer solution for this problem?

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  • how to fix error in bitmap size exceeds VM budget

    - by narasimha
    hi folks i am working one application image uploading to sdcard i am scaling that sdcard saved into database some times one error is occurs bitmap size exceeds vm budget ouput : 01-11 15:39:51.809: ERROR/AndroidRuntime(6214): Uncaught handler: thread main exiting due to uncaught exception 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): java.lang.OutOfMemoryError: bitmap size exceeds VM budget 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at android.graphics.BitmapFactory.nativeDecodeByteArray(Native Method) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at android.graphics.BitmapFactory.decodeByteArray(BitmapFactory.java:384) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at android.graphics.BitmapFactory.decodeByteArray(BitmapFactory.java:397) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at com.fitzgeraldsoftware.shout.presentationLayer.Shout.onActivityResult(Shout.java:1653) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at android.app.Activity.dispatchActivityResult(Activity.java:3624) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at android.app.ActivityThread.deliverResults(ActivityThread.java:3220) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at android.app.ActivityThread.handleSendResult(ActivityThread.java:3266) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at android.app.ActivityThread.access$2600(ActivityThread.java:116) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1823) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at android.os.Handler.dispatchMessage(Handler.java:99) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at android.os.Looper.loop(Looper.java:123) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at android.app.ActivityThread.main(ActivityThread.java:4203) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at java.lang.reflect.Method.invokeNative(Native Method) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at java.lang.reflect.Method.invoke(Method.java:521) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549) 01-11 15:39:51.979: ERROR/AndroidRuntime(6214): at dalvik.system.NativeStart.main(Native Method) how can fix the error please forward some solution thanks in advance

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  • Using forward declarations for build in datatypes.

    - by bdhar
    I understand that wherever possible we shall use forward declarations instead of includes to speed up the compilation. I have a class Person like this. #pragma once #include <string> class Person { public: Person(std::string name, int age); std::string GetName(void) const; int GetAge(void) const; private: std::string _name; int _age; }; and a class Student like this #pragma once #include <string> class Person; class Student { public: Student(std::string name, int age, int level = 0); Student(const Person& person); std::string GetName(void) const; int GetAge(void) const; int GetLevel(void) const; private: std::string _name; int _age; int _level; }; In Student.h, I have a forward declaration class Person; to use Person in my conversion constructor. Fine. But I have done #include <string> to avoid compilation error while using std::string in the code. How to use forward declaration here to avoid the compilation error? Is it possible? Thanks.

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  • java.lang.ExceptionInInitializerError Exception when creating Application Context in Spring

    - by cyotee
    I am practicing with Spring, and am getting a java.lang.ExceptionInInitializerError exception when I try to instantiate the context. The Exception appears below, with my code following it. I have simplified my experiment from before. The Exception Oct 17, 2012 5:54:22 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@570c16b7: startup date [Wed Oct 17 17:54:22 CDT 2012]; root of context hierarchy Exception in thread "main" java.lang.ExceptionInInitializerError at org.springframework.context.support.AbstractRefreshableApplicationContext.createBeanFactory(AbstractRefreshableApplicationContext.java:195) at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:128) at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:535) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:449) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83) at helloworld.HelloWorldTest.main(HelloWorldTest.java:13) Caused by: java.lang.NullPointerException at org.springframework.beans.factory.support.DefaultListableBeanFactory.<clinit>(DefaultListableBeanFactory.java:105) ... 7 more My configuration XML <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:c="http://www.springframework.org/schema/c" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd"> <bean id="messageContainer" class="helloworld.MessageContainer"> <property name="message" value="Hello World"> </property> </bean> <bean id="messageOutputService" class="helloworld.MessageOutputService"> </bean> My test class. package helloworld; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class HelloWorldTest { /** * @param args */ public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext("HelloWorldTest-context.xml"); MessageContainer message = context.getBean(MessageContainer.class); MessageOutputService service = context.getBean(MessageOutputService.class); service.outputMessageToConsole(message); } }

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  • Why would I need a using statement to Libary B extn methods, if they're used in Library A & it's Li

    - by Greg
    Hi, I have: Main Program Class - uses Library A Library A - has partial classes which mix in methods from Library B Library B - mix in methods & interfaces Why would I need a using statement to LibaryB just to get their extension methods working in the main class? That is given that it's Library B that defines the classes that will be extended. EDIT - Except from code // *** PROGRAM *** using TopologyDAL; using Topology; // *** THIS WAS NEEDED TO GET EXTN METHODS APPEARING *** class Program { static void Main(string[] args) { var context = new Model1Container(); Node myNode; // ** trying to get myNode mixin methods to appear seems to need using line to point to Library B *** } } // ** LIBRARY A namespace TopologyDAL { public partial class Node { // Auto generated from EF } public partial class Node : INode<int> // to add extension methods from Library B { public int Key } } // ** LIBRARY B namespace ToplogyLibrary { public static class NodeExtns { public static void FromNodeMixin<T>(this INode<T> node) { // XXXX } } public interface INode<T> { // Properties T Key { get; } // Methods } }

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  • Singleton Pattern combine with a Decorator

    - by Mike
    Attached is a classic Decorator pattern. My question is how would you modify the below code so that you can wrap zero or one of each topping on to the Pizza Right now I can have a Pepporini - Sausage -- Pepporini -- Pizza class driving the total cost up to $10, charging twice for Pepporini. I don't think I want to use the Chain of Responsibility pattern as order does not matter and not all toppings are used? Thank you namespace PizzaDecorator { public interface IPizza { double CalculateCost(); } public class Pizza: IPizza { public Pizza() { } public double CalculateCost() { return 8.00; } } public abstract class Topping : IPizza { protected IPizza _pizzaItem; public Topping(IPizza pizzaItem) { this._pizzaItem = pizzaItem; } public abstract double CalculateCost(); } public class Pepporini : Topping { public Pepporini(IPizza pizzaItem) : base(pizzaItem) { } public override double CalculateCost() { return this._pizzaItem.CalculateCost() + 0.50; } } public class Sausage : Topping { public Sausage(IPizza pizzaItem) : base(pizzaItem) { } public override double CalculateCost() { return this._pizzaItem.CalculateCost() + 1.00; } } public class Onions : Topping { public Onions(IPizza pizzaItem) : base(pizzaItem) { } public override double CalculateCost() { return this._pizzaItem.CalculateCost() + .25; } } }

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  • Adding jQuery event handler to expand div when a link is clicked

    - by hollyb
    I'm using a bit of jQuery to expand/hide some divs. I need to add an event handler so that when a link is clicked, it opens a corrisponding div. Each toggled div will have a unique class assigned to it. I am looking for some advice about how to build the event handler. The jQuery $(document).ready(function(){ $(".toggle_container:not(:first)").hide(); $(".toggle_container:first").show(); $("h6.trigger:first").addClass("active"); $("h6.trigger").click(function(){ $(this).toggleClass("active"); $(this).next(".toggle_container").slideToggle(300); }); The css: // uses a background image with an on (+) and off (-) state stacked on top of each other h6.trigger { background: url(buttonBG.gif) no-repeat;height: 46px;line-height: 46px;width: 300px;font-size: 2em;font-weight: normal;} h6.trigger a {color: #fff;text-decoration: none; display: block;} h6.active {background-position: left bottom;} .toggle_container { overflow: hidden; } .toggle_container .block {padding: 20px;} The html has a list of links, such as: <a href="#">One</a> <a href="#">Two</a> and the coorisponding divs to open: <h6 class="trigger">Container one</h6> <div class="toggle_container"> div one </div> <h6 class="trigger">Container two</h6> <div class="toggle_container Open"> div one </div> As I mentioned, I will be assigning a unique class to facilitate this. Any advice? Thanks! To clarify, i'm looking for some advice to build an event handler to toggle open a specific div when a link is clicked from a different part of the page, from a nav for instance.

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  • Dynamically setting the queryset of a ModelMultipleChoiceField to a custom recordset

    - by Daniel Quinn
    I've seen all the howtos about how you can set a ModelMultipleChoiceField to use a custom queryset and I've tried them and they work. However, they all use the same paradigm: the queryset is just a filtered list of the same objects. In my case, I'm trying to get the admin to draw a multiselect form that instead of using usernames as the text portion of the , I'd like to use the name field from my account class. Here's a breakdown of what I've got: # models.py class Account(models.Model): name = models.CharField(max_length=128,help_text="A display name that people understand") user = models.ForeignKey(User, unique=True) # Tied to the User class in settings.py class Organisation(models.Model): administrators = models.ManyToManyField(User) # admin.py from django.forms import ModelMultipleChoiceField from django.contrib.auth.models import User class OrganisationAdminForm(forms.ModelForm): def __init__(self, *args, **kwargs): from ethico.accounts.models import Account self.base_fields["administrators"] = ModelMultipleChoiceField( queryset=User.objects.all(), required=False ) super(OrganisationAdminForm, self).__init__(*args, **kwargs) class Meta: model = Organisation This works, however, I want queryset above to draw a selectbox with the Account.name property and the User.id property. This didn't work: queryset=Account.objects.all().order_by("name").values_list("user","name") It failed with this error: 'tuple' object has no attribute 'pk' I figured that this would be easy, but it's turned into hours of dead-ends. Anyone care to shed some light?

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  • General String Encryption in .NET

    - by cryptospin
    I am looking for a general string encryption class in .NET. (Not to be confused with the 'SecureString' class.) I have started to come up with my own class, but thought there must be a .NET class that already allows you to encrypt/decrypt strings of any encoding with any Cryptographic Service Provider. Public Class SecureString Private key() As Byte Private iv() As Byte Private m_SecureString As String Public ReadOnly Property Encrypted() As String Get Return m_SecureString End Get End Property Public ReadOnly Property Decrypted() As String Get Return Decrypt(m_SecureString) End Get End Property Public Sub New(ByVal StringToSecure As String) If StringToSecure Is Nothing Then StringToSecure = "" m_SecureString = Encrypt(StringToSecure) End Sub Private Function Encrypt(ByVal StringToEncrypt As String) As String Dim result As String = "" Dim bytes() As Byte = Text.Encoding.UTF8.GetBytes(StringToEncrypt) Using provider As New AesCryptoServiceProvider() With provider .Mode = CipherMode.CBC .GenerateKey() .GenerateIV() key = .Key iv = .IV End With Using ms As New IO.MemoryStream Using cs As New CryptoStream(ms, provider.CreateEncryptor(), CryptoStreamMode.Write) cs.Write(bytes, 0, bytes.Length) cs.FlushFinalBlock() End Using result = Convert.ToBase64String(ms.ToArray()) End Using End Using Return result End Function Private Function Decrypt(ByVal StringToDecrypt As String) As String Dim result As String = "" Dim bytes() As Byte = Convert.FromBase64String(StringToDecrypt) Using provider As New AesCryptoServiceProvider() Using ms As New IO.MemoryStream Using cs As New CryptoStream(ms, provider.CreateDecryptor(key, iv), CryptoStreamMode.Write) cs.Write(bytes, 0, bytes.Length) cs.FlushFinalBlock() End Using result = Text.Encoding.UTF8.GetString(ms.ToArray()) End Using End Using Return result End Function End Class

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  • Cast object to interface when created via reflection

    - by Al
    I'm trying some stuff out in Android and I'm stuck at when trying to cast a class in another .apk to my interface. I have the interface and various classes in other .apks that implement that interface. I find the other classes using PackageManager's query methods and use Application#createPackageContext() to get the classloader for that context. I then load the class, create a new instance and try to cast it to my interface, which I know it definitely implements. When I try to cast, it throws a class cast exception. I tried various things like loading the interface first, using Class#asSubclass, etc, none of which work. Class#getInterfaces() shows the interface is implemented. My code is below: PackageManager pm = getPackageManager(); List<ResolveInfo> lr = pm.queryIntentServices(new Intent("com.example.some.action"), 0); ArrayList<MyInterface> list = new ArrayList<MyInterface>(); for (ResolveInfo r : lr) { try { Context c = getApplication().createPackageContext(r.serviceInfo.packageName, Context.CONTEXT_IGNORE_SECURITY | Context.CONTEXT_INCLUDE_CODE); ClassLoader cl = c.getClassLoader(); String className = r.serviceInfo.name; if (className != null) { try { Class<?> cls = cl.loadClass(className); Object o = cls.newInstance(); if (o instanceof MyInterface) { //fails list.add((MyInterface) o); } } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } // some exceptions removed for readability } } catch (NameNotFoundException e1) { e1.printStackTrace(); }

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  • @PrePersist with entity inheritance

    - by gerry
    I'm having some problems with inheritance and the @PrePersist annotation. My source code looks like the following: _the 'base' class with the annotated updateDates() method: @javax.persistence.Entity @Inheritance(strategy = InheritanceType.TABLE_PER_CLASS) public class Base implements Serializable{ ... @Id @GeneratedValue protected Long id; ... @Column(nullable=false) @Temporal(TemporalType.TIMESTAMP) private Date creationDate; @Column(nullable=false) @Temporal(TemporalType.TIMESTAMP) private Date lastModificationDate; ... public Date getCreationDate() { return creationDate; } public void setCreationDate(Date creationDate) { this.creationDate = creationDate; } public Date getLastModificationDate() { return lastModificationDate; } public void setLastModificationDate(Date lastModificationDate) { this.lastModificationDate = lastModificationDate; } ... @PrePersist protected void updateDates() { if (creationDate == null) { creationDate = new Date(); } lastModificationDate = new Date(); } } _ now the 'Child' class that should inherit all methods "and annotations" from the base class: @javax.persistence.Entity @NamedQueries({ @NamedQuery(name=Sensor.QUERY_FIND_ALL, query="SELECT s FROM Sensor s") }) public class Sensor extends Entity { ... // additional attributes @Column(nullable=false) protected String value; ... // additional getters, setters ... } If I store/persist instances of the Base class to the database, everything works fine. The dates are getting updated. But now, if I want to persist a child instance, the database throws the following exception: MySQLIntegrityConstraintViolationException: Column 'CREATIONDATE' cannot be null So, in my opinion, this is caused because in Child the method "@PrePersist protected void updateDates()" is not called/invoked before persisting the instances to the database. What is wrong with my code?

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  • Jquery Blinking issues when using 2 .hover

    - by user1897502
    I want to do 2 .hover : first when the cursor is hover the image icons should appear on the image second when the cursor is hover a specific icon, (for exemple info) a div with the informations should appear I have nearly sucess but I have blinkin problems and when I use the two .hover function the information popup does not show up. here my html {LinkOpenTag}<div class="centrage"><div class="photoDiv"><img src="{PhotoURL-500}" alt="{PhotoAlt}" /> <div class="icons"> {block:Exif} <span class="info"><span> <div class="exif" style="display: none; opacity: 0"> <ol class="CameraMeta"> <li>{block:Camera}Camera: {Camera}{/block:Camera}</li> <li>{block:Aperture}Aperture: {Aperture}{/block:Aperture}</li> <li>{block:Exposure}Exposure: {Exposure}{/block:Exposure}</li> <li>{block:FocalLength}Focal Length: {FocalLength}{/block:FocalLength}</li> </ol> </div> {/block:Exif} </div> </div>{LinkCloseTag} and here my jquery <script type="text/javascript"> $(".photoDiv img").hover( function() { $(this).next().css("visibility", "visible"); }, function() { $(this).next().css("visibility", "hidden"); } ); $("span.info").hover( function() { $(".exif").css("display", "block"); $(".exif").css("opacity", "1"); }, function() { $(".exif").css("display", "none"); $(".exif").css("opacity", "0"); } ); Thanks for your time :)

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  • CSS horizontal scrolling box

    - by tony noriega
    im trying to create a horizontal scrolling box to create a "timeline" effect... but i cant seem to get it to scroll horizontally, versus the vertical scroll bar that shows up...thoughts? #container{ width:500px; height:250px; border:1px solid #cc61b8; overflow:auto; } .container-bits{ width:250px; height:498px; float:left; } <div id="container"> <div class="container-bits">Content Here</div> <div class="container-bits">Content Here</div> <div class="container-bits">Content Here</div> <div class="container-bits">Content Here</div> <div class="container-bits">Content Here</div> <div class="container-bits">Content Here</div> </div>

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  • CSS Float statement

    - by Jordan Pagaduan
    .float1 { float: left; width: 50%; height: 50%; } .float2 { float: right; width: 50%; height: 50%; } .float3 { float: left; width: 50%; height: 50%; } .float4 { float: right; width: 50%; height: 50%; } .clear { clear: both; } HTML: <div class="float1">Float 1</div> <div class="float2">Float 2</div> <div class="clear"></div> <div class="float3">Float 3</div> <div class="float4">Float 4</div> <div class="clear"></div> I want an output like this image: Please Correct my css code. Thank you.

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  • How to use PHP preg_replace regular expression to find and replace text

    - by Roger
    I wrote this PHP code to make some substitutions: function cambio($txt){ $from=array( '/\+\>([^\+\>]+)\<\+/', //finds +>text<+ '/\%([^\%]+)\%/', //finds %text% ); $to=array( '<span class="P">\1</span>', '<span>\1</span>', ); return preg_replace($from,$to,$txt); } echo cambio('The fruit I most like is: +> %apple% %banna% %orange% <+.'); Resulting into this: The fruit I most like is: <span class="P"> <span>apple</span> <span>banna</span> <span>orange</span> </span>. however I needed to identify the fruit's span tags, like this: The fruit I most like is: <span class="P"> <span class="a">apple</span> <span class="b">banna</span> <span class="c">coco</span> </span>. I'd buy a fruit to whom discover a regular expression to accomplish this :-)

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  • How to escape HTML.

    - by kokila
    I have a string which contains HTML text. I need to escape just the strings and not tags. For example, I have string which contains, <ul class="main_nav"> <li> <a class="className1" id="idValue1" tabindex="2">Test & Sample</a> </li> <li> <a class="className2" id="idValue2" tabindex="2">Test & Sample2</a> </li> </ul> How to escape just the text to, <ul class="main_nav"> <li> <a class="className1" id="idValue1" tabindex="2">Test &amp; Sample</a> </li> <li> <a class="className2" id="idValue2" tabindex="2">Test &amp; Sample2</a> </li> </ul> with out modifying the tags. Can this be handled with HTML DOM and javascript? Thanks

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  • How do I do client-side form validation in jQuery?

    - by marcamillion
    I am trying to use this plugin: http://docs.jquery.com/Plugins/Validation Where #user_new is the id for my form, this is what my code looks like: $('#user_new').validate({ rules: { user[username]: "required", user[email]: { required: true, email: true } }, messages: { user[username]: "Please specify your name", user[email]: { required: "We need your email address to contact you", email: "Your email address must be in the format of [email protected]" } } }) Where these are how my input fields look when the page is rendered (generated by Rails): <input class="clearField curved" id="user_f_name" name="user[f_name]" size="30" type="text" value="First Name" /><br /> <input class="clearField curved" id="user_l_name" name="user[l_name]" size="30" type="text" value="Last Name" /><br /> <input class="clearField curved" id="user_username" name="user[username]" size="30" type="text" value="Username" /><br /> <input class="clearField curved" id="user_password" name="user[password]" size="30" type="password" value="Password" /><br /> <input class="clearField curved" id="user_password_confirmation" name="user[password_confirmation]" size="30" type="password" value="Password" /><br /> <input class="clearField curved" id="user_email" name="user[email]" size="30" type="text" value="Email Address" /><br /> I was just trying to validate username & email first. Then take it from there. For the life of me, I can't figure out how to specify the syntax and the rules for working with this plugin. Help!

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  • Where do I put javaassist code?

    - by DutrowLLC
    I have an application running on google app engine. I'm using restlets and I have a couple of layers set up including the restlet layer, the model layer, the business layer, and the data layer. I'm attempting to use javaassist to modify some classes, but I'm unsure where to actually put the code. I tried to put the code in the static initialization block: public class Person { String firstName; String getFirstName(){return null;} static{ ClassPool pool = ClassPool.getDefault(); try { CtClass CtPerson = pool.get("Person"); CtMethod CtGetFirstName = CtPerson.getDeclaredMethod("GetFirstName"); CtGetFirstName.setBody("return firstName;"); CtPerson.toClass(); } catch (Exception e) { e.printStackTrace(); } } } ...but that resulted in this error: javassist.CannotCompileException:.....attempted duplicate class definition...". I guess it makes sense that I can't edit the class file in the middle of its generation. I know the code works because I was able to run it correctly by simply putting it in a location that would run when I sent the program a command. (accessed a Restlet resource). The code ran fine if an instance of the class had not already been instantiated, however once I instantiated an instance of the affected class, the javaassist code failed. I assume I need to put this code somewhere that it will only run either: once after the program starts, directly before a class is instantiated for the first time, or even better, during compile time.

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  • A bit confused about OOP and PHP.

    - by Pirkka
    Hello I have programmed with procedural style a lot before and in these few months I have decided to go OOP. Im a bit confused about OOP and PHP. Lets say I have Categories table and Pages table in my database. I would like to do a page-class and a category-class. Lets say I would have a page that showed information about the category and there would be a list of pages that belong to the category. How would I implement that in OOP way? I have thought that the category class would have a property (array) that would contain all the pages that it has. Well then comes the part that I`m confused about. Should I have a method that would get all the pages with correct categoryID from the database and should I instantiate all the rows as an Page-object? Or should I have a setPages-method in the Category-class and getAllPages-method in the Pages-class and with that method I would set all the pages to the Category-class. Huh Im lost. :D

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  • Calling delegate methods and calling selectors

    - by Crystal
    I'm new to the concept of delegates and selectors when used with notifications. So my first question is, 1) Let's say you have a button that has a delegate that implements some doWork method. If you want the same functionality that's in the method, is it 'ok' to just call that method? I didn't know if that was considered good coding practices and/or if you should do that, or do something different in getting that type of functionality. Like if that is ok architecture? 2) Similarly, with NSNotificationCenter, I see some code that posts a notification. Then there's a HandleSegmentedControl:(NSNotification *)notification method. If I want to manually have that functionality, but without pressing the segment control, is it 'ok' to just take that functionality out of that method and put it in a new method so it would look like this: Original: - (void)HandleSegmentedControl:(NSNotification *)notification { NSDictionary *dict = [userInfo notification]; // do stuff with the dictionary } New: - (void)HandleSegmentedControl:(NSNotification *)notification { NSDictionary *dict = [userInfo notification]; [self newMethod:dict]; } - (void)newMethod:(NSDictionary *)dict { // do stuff with the dictionary } - (void)myOtherMethodThatNeedsTheSameFunctionality { NSDictionary *dict = // create some dictionary [self newMethod:dict]; } Sorry if these are basic questions. I'm not sure what the best practices are for things like this and wanted to start the right way. Thanks.

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  • Convert date to string upon saving a doctrine record

    - by takteek
    Hi, I'm trying to migrate one of my PHP projects to Doctrine. I've never used it before so there are a few things I don't understand. In my current code, I have a class similar to this: class ScheduleItem { private Date start; //A PEAR Date object. private Date end; public function getStart() { return $this-start; } public function setStart($val) { $this-start = $val; } public function getEnd() { return $this-end; } public function setEnd($val) { $this-end= $val; } } I have a ScheduleItemDAO class with methods like save(), getByID(), etc. When loading from and saving to the database, the DAO class converts the Date objects to and from strings so they can be stored in a timestamp field. In my attempt to move to Doctrine, I created a new class like this: class ScheduleItem extends Doctrine_Record { public function setTableDefinition() { $this-hasColumn('start', 'timestamp'); $this-hasColumn('end', 'timestamp'); } } I had hoped I would be able to use Date objects for the start and end times, and have them converted to strings when they are saved to the database. How can I accomplish this?

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  • Implementation/interface inheritance design question.

    - by Neil G
    I would like to get the stackoverflow community's opinion on the following three design patterns. The first is implementation inheritance; the second is interface inheritance; the third is a middle ground. My specific question is: Which is best? implementation inheritance: class Base { X x() const = 0; void UpdateX(A a) { y_ = g(a); } Y y_; } class Derived: Base { X x() const { return f(y_); } } interface inheritance: class Base { X x() const = 0; void UpdateX(A a) = 0; } class Derived: Base { X x() const { return x_; } void UpdateX(A a) { x_ = f(g(a)); } X x_; } middle ground: class Base { X x() const { return x_; } void UpdateX(A a) = 0; X x_; } class Derived: Base { void UpdateX(A a) { x_ = f(g(a)); } } I know that many people prefer interface inheritance to implementation inheritance. However, the advantage of the latter is that with a pointer to Base, x() can be inlined and the address of x_ can be statically calculated.

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  • JTable Insert row and refresh

    - by user269723
    Hi All, I am trying to create simple application where JTable gets updated and refreshed after data is changed.Structure is as follows. 1)Class Main which contains JFrame,JTable details. 2)SampleTableModel class which extends AbstractTableModel.I am overriding most of the methods.`import javax.swing.table.; import javax.swing.event.; import java.util.*; public class SampleTableModel extends AbstractTableModel { public SampleTableModel(){ // this.addTableModelListener( } String[] columnNames = {"A","B","C","D","E"}; int[][] data = {{1,2,3,4,5},{5,6,7,8,9},{12,13,14,15,16}}; Vector dataVector = new Vector(); public Object getValueAt(int rowIndex,int columnIndex) { return data[rowIndex][columnIndex]; } public int getColumnCount(){ return 5; } public int getRowCount(){ return 3; } public String getColumnName(int columnIndex){ return columnNames[columnIndex]; } public void setValueAt(Object value,int row,int column){ data[row][column] =99; } public void notifyTable(AEMessage message){ /* * This method will be called from another class to update JTable. * */ data[0][1]=999; data[0][2]=8838; data[1][1]=8883; fireTableRowsUpdated(0,3); } } ` As you can see, notifyTable will be called from another class(which is actually a thread-which calls this method frequently) Problem is I don't see data being changed in JTable.I see only the initialized data. In the Main class- I am setting like this- RVJDataTable.setModel(new SampleTableModel());

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  • JQuery Dragging Outside Parent

    - by Andy
    I'm using JQuery's draggable(); to make li elements draggable. The only problem is when the element is dragged outside its parent, it doesn't show up. That is, it doesn't leave the confines of its parent div. An example is here: http://imgur.com/N2N1L.png - it's as if the z-index for everything else has greater priority (and the element slides under everything). Here's the code: $('.photoList li').draggable({ distance: 20, snap: theVoteBar, revert: true, containment: 'document' }); And the li elements are placed in DIVs like this: <div class="coda-slider preload" id="coda-slider-1"> <div class="panel"> <div class="panel-wrapper"> <h2 class="title" style="display:none;">Page 1</h2> <ul class="photoList"> <li> <img class="ui-widget-content" src="photos/1.jpg" style="width:100px;height:100px;" /> </li> </ul> </div> </div> I'm positive the problem is it won't leave its parent container, but I'm not sure what to do to get it out. Any direction or help would be appreciated GREATLY!

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  • Question about cloning in Java

    - by devoured elysium
    In Effective Java, the author states that: If a class implements Cloneable, Object's clone method returns a field-by-field copy of the object; otherwise it throws CloneNotSupportedException. What I'd like to know is what he means with field-by-field copy. Does it mean that if the class has X bytes in memory, it will just copy that piece of memory? If yes, then can I assume all value types of the original class will be copied to the new object? class Point { private int x; private int y; @Override public Point clone() { return (Point)super.clone(); } } If what Object.clone() does is a field by field copy of the Point class, I'd say that I wouldn't need to explicitly copy fields x and y, being that the code shown above will be more than enough to make a clone of the Point class. That is, the following bit of code is redundant: @Override public Point clone() { Point newObj = (Point)super.clone(); newObj.x = this.x; //redundant newObj.y = this.y; //redundant } Am I right? I know references of the cloned object will point automatically to where the original object's references pointed to, I'm just not sure what happens specifically with value types. If anyone could state clearly what Object.clone()'s algorithm specification is (in easy language) that'd be great. Thanks

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