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  • Can you explain what's going on in this Ruby code?

    - by samoz
    I'm trying to learn Ruby as well as Ruby on Rails right now. I'm following along with Learning Rails, 1st edition, but I'm having a hard time understanding some of the code. I generally do work in C, C++, or Java, so Ruby is a pretty big change for me. I'm currently stumped with the following block of code for a database migrator: def self.up create_table :entries do |t| t.string :name t.timestamps end end Where is the t variable coming from? What does it actually represent? Is it sort of like the 'i' in a for(i=0;i<5;i++) statement? Also, where is the :entries being defined at? (entries is the name of my controller, but how does this function know about that?)

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  • numpy array C api

    - by wiso
    I have a C++ function returning a std::vector and I want to use it in python, so I'm using the C numpy api: static PyObject * py_integrate(PyObject *self, PyObject *args){ ... std::vector<double> integral; cpp_function(integral); // this change integral npy_intp size = {integral.size()}; PyObject *out = PyArray_SimpleNewFromData(1, &size, NPY_DOUBLE, &(integral[0])); return out; } when I call it from python, if I do import matplotlib.pyplot as plt a = py_integrate(parameters) print a fig = plt.figure() ax = fig.add_subplot(111) ax.plot(a) print a the first print is ok, the values are correct, but when I plot a they are not, and in particular in the second print I see very strange values like 1E-308 1E-308 ... or 0 0 0 ... as an unitialized memory. I don't understand why the first print is ok.

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  • Implementing a 'Send Feedback' feature in a Java desktop application

    - by William
    I would like to implement a 'Send Feedback' option in a Java desktop application. One which will pop up a box for the user to enter a comment, then send it to us along with a screenshot of the application window. How would be the best way to communicate the data to us? Two obvious solutions spring to mind: Email - I'm thinking that the application would connect to an SMTP server set-up by us, with the username/password somehow hidden in the code. SMTP over SSL for security (not of the data being sent, but of the SMTP username/password). Web service - pretty self explanatory. Which of these would be best, or is there a better alternative?

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  • c# object initializer complexity. best practice

    - by Andrew Florko
    I was too excited when object initializer appeared in C#. MyClass a = new MyClass(); a.Field1 = Value1; a.Field2 = Value2; can be rewritten shorter: MyClass a = new MyClass { Field1 = Value1, Field2 = Value2 } Object initializer code is more obvious but when properties number come to dozen and some of the assignment deals with nullable values it's hard to debug where the "null reference error" is. Studio shows the whole object initializer as error point. Nowadays I use object initializer for straightforward assignment only for error-free properties. How do you use object initializer for complex assignment or it's a bad practice to use dozen of assigments at all? Thank you in advance!

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  • J2ME app to access incoming call - Where to start?

    - by Jay
    Here's my requirement: I often receive calls from unidentified numbers on my mobile phones. I would like an application which would use a reference list like this, and show me the carrier name and the area of origin along with the number on screen. Mobile make : Sony Ericsson Model : C902 Operating System: Propreitary J2ME: MIDP 2.0 Here are my questions: Is it possible to do something like this? I have installed a lot of java apps on my mobile, and all of them have to be launched seperately, can be run in the background, but they never seem to access anything native. If it is possible, which area of J2Me should I start with, for creating an application that achieves the above requirement? If it is not possbile, what are my alternatives?

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  • Passing session data to ModelForm inside of ModelAdmin

    - by theactiveactor
    I'm trying to initialize the form attribute for MyModelAdmin class inside an instance method, as follows: class MyModelAdmin(admin.ModelAdmin): def queryset(self, request): MyModelAdmin.form = MyModelForm(request.user) My goal is to customize the editing form of MyModelForm based on the current session. When I try this however, I keep getting an error (shown below). Is this the proper place to pass session data to ModelForm? If so, then what may be causing this error? TypeError at ... Exception Type: TypeError Exception Value: issubclass() arg 1 must be a class Exception Location: /usr/lib/pymodules/python2.6/django/forms/models.py in new, line 185

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  • Android source referencing missing classes

    - by jqpubliq
    I cloned some of the trees from the Android Open Source Project to take a look at the code, but I can't build them because they reference classes which don't seem to exist. For instance, the music application here references android.media.MediaFile which according to the package summary does not exist, as well as things like ArrayListCursor which has an old javadoc around but is absent in current documentation. So is the open source project disjoint from the released SDK? Also, is there a way to build these open source packages with the current SDK? Thanks, -JQP

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  • How to pass the image from oneview to another view in iphone?

    - by Warrior
    I am new to iphone development.I want to display the image selected in a seperateview.I have used UIImagePickerController to pick the image from device library.On clicking the image i have to navigate to another view and display the image.How can i send the image o another view.I have used delegate methods for accessing string in other views.Is there any possibility to send the image via delegate methods. - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)img1 editingInfo:(NSDictionary *)editInfo { [[picker parentViewController] dismissModalViewControllerAnimated:YES]; EmailPictureViewController *email = [[EmailPictureViewController alloc] initWithNibName:@"EmailPictureViewController" bundle:nil]; [self.navigationController pushViewController:email animated:YES]; } From the above code i have to set delegates for img1 which is of type UIImage. Is there any other way to achieve my task.Please help me out.Thanks.

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  • Swing Timer in Conjunction with Possible Long-running Background Task

    - by javacavaj
    I need to perform a task repeatedly that affects both GUI-related and non GUI-related objects. One caveat is that no action should performed if the previous task had not completed when the next timer event is fired. My initial thoughts are to use a SwingTimer in conjunction with a javax.swing.SwingWorker object. The general setup would look like this. class { timer = new Timer(speed, this); timer.start(); public void actionPerformed(ActionEvent e) { SwingWorker worker = new SwingWorker() { @Override public ImageIcon[] doInBackground() { // potential long running task } @Override public void done() { // update GUI on event dispatch thread when complete } } } Some potential issues I see with this approach are: 1) Multiple SwingWorkers will be active if a worker has not completed before the next ActionEvent is fired by the timer. 2) A SwingWorker is only designed to be executed once, so holding a reference to the worker and reusing (is not?) a viable option. Is there a better way to achieve this?

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  • Classic ASP and MVC side-by-side, different projects?

    - by David Lively
    I've tried asking this in a few different ways, but let's give it another shot (as I've yet to receive an answer and this is driving me nuts!) I have a very large classic ASP 3.0 application (~350K lines) that I want to start migrating to ASP.NET MVC. I'd like to keep the old ASP files in a separate project from the MVC stuff. Ideas on how to debug these? Should I just dump the files in the same folder and create two different projects ( a WAP and an MVC app) that reference the relevant files and folders required by each? This should work, but does anyone have a better idea? I need the ability to migrate small parts of the application individually as this will probably take a year or two to complete.

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  • Where are AnkhSVN CA certificates stored?

    - by Roger Lipscombe
    My Subversion repository is available over HTTPS. I've got a self-signed CA root certificate, and the server uses a certificate signed with that. The CA root certificate is stored in Trusted Root Certification Authorities, which means that (for example) Internet Explorer recognises it. AnkhSVN, on the other hand, reports "There are some problems with this server's certificate". So: what is AnkhSVN using as its certificate store? It doesn't appear to be the Windows one. And how do I put my CA root certificate in there?

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  • Custom Item in ListActivity on Android

    - by Honza Pokorny
    Hello everyone, I've spent hours reading through the SDK reference, googling and reading tutorials - but I still can't figure it out. I would like to know how to create a custom list item in the ListActivity widget on Android. Something similar to a Twitter client interface. Each list item has different types of text, possibly an icon, etc. Does anyone know of any resources that would help me understand the process of creating something like that? Any guidance would be appreciated. Thanks

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  • Sending information back from delegate [iPhone]

    - by Andy
    I'm using NSXMLParser in my RootViewController.m file. NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithData:response_data]; [xmlParser setDelegate:self]; [xmlParser parse]; [xmlParser release]; I'm also implementing this method to add entries to a dictionary defined in RootViewController.m for later use: - (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qualifiedName attributes:(NSDictionary *)attributeDict However, I'd like to get more than one XML file and do different things when the file has finished; this sounds like I need to use external files as delegates. My question is: If I have the following implementation files (& their header files): RootViewController.m XMLDelegate1.m XMLDelegate2.m and set the ith NSXMLParser delegate to be XMLDelegatei.m, and get those files to return an NSDictionary that I can then add to the NSDictionary defined in RootViewController.m. I guess there are two methods of doing this: Use a method that I don't know about; or Use a better workflow I suspect it's 2, but hope it's 1. Thanks, Andy

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  • Inheritance in Ruby on Rails: setting the base class type

    - by Régis B.
    I am implementing a single table inheritance inside Rails. Here is the corresponding migration: class CreateA < ActiveRecord::Migration def self.up create_table :a do |t| t.string :type end end Class B inherits from A: class B < A end Now, it's easy to get all instances of class B: B.find(:all) or A.find_all_by_type("B") But how do I find all instances of class A (those that are not of type B)? Is this bad organization? I tried this: A.find_all_by_type("A") But instances of class A have a nil type. I could do A.find_all_by_type(nil) but this doesn't feel right, somehow. In particular, it would stop working if I decided to make A inherit from another class. Would it be more appropriate to define a default value for :type in the migration? Something like: t.string :type, :default => "A" Am I doing something wrong here?

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  • AS3 Accessing Variables of Parent Class From Child

    - by TheDarkIn1978
    i'm trying to assign a parent's variable from the parent's child //Parent public class Main extends Sprite { public var selectedSquare:Sprite; public function Main() { //inits and adds new Square child class to display list } ... ------- //Child public function dragSquare(evt:MouseEvent):void { Sprite(parent).selectedSquare = this; //evil doesn't work! parent.addChild(this); this.startDrag(); } i'm receiving this error, but i'm casting parent from displayObjectContainer to a Sprite so i have no idea why it's not working. 1119: Access of possibly undefined property selectedSquare through a reference with static type flash.display:Sprite.

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  • Documenting preprocessor defines in Doxygen

    - by Fire Lancer
    Is it possible to document preprocessor defines in Doxygen? I expected to be able to do it just like a variable or function, however the Doxygen output appears to have "lost" the documentation for the define, and does not contain the define its self either. I tried the following /**My Preprocessor Macro.*/ #define TEST_DEFINE(x) (x*x) and /**@def TEST_DEFINE My Preprocessor Macro. */ #define TEST_DEFINE(x) (x*x) I also tried putting them within a group (tried defgroup, addtogroup and ingroup) rather than just at the "file scope" however that had no effect either (although other items in the group were documented as intended). I looked through the various Doxygen options, but couldn't see anything that would enable (or prevent) the documentation of defines.

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  • Ruby: Calling class method from instance

    - by Peter
    In Ruby, how do you call a class method from one of that class's instances? Say I have class Truck def self.default_make # Class method. "mac" end def initialize # Instance method. Truck.default_make # gets the default via the class's method. # But: I wish to avoid mentioning Truck. Seems I'm repeating myself. end end the line Truck.default_make retrieves the default. But is there a way of saying this without mentioning Truck? It seems like there should be.

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  • Changing the size of the UISearchBar TextField ?

    - by Padraig
    I have a UITableView with an Index on the side; I want to add a UISearchBar to it, but the index overlaps with the "x" to clear the search. I've noticed in the Contacts application, the textfield within the UISearchBar is resized to accommodate this, but I can't work out how to do this in my own app. I have tried the following in my viewDidLoad, but it does not seem to work. UITextField * textField = (UITextField *)[[self.search subviews] objectAtIndex:0]; CGRect r = textField.frame; [textField setFrame:CGRectMake(r.origin.x, r.origin.y, r.size.height, r.size.width-30)]; Any ideas?

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  • Trying and expand the contrib.auth.user model and add a "relatipnships" manage

    - by dotty
    I have the following model setup. from django.db import models from django.contrib.auth.models import User class SomeManager(models.Manager): def friends(self): # return friends bla bla bla class Relationship(models.Model): """(Relationship description)""" from_user = models.ForeignKey(User, related_name='from_user') to_user = models.ForeignKey(User, related_name='to_user') has_requested_friendship = models.BooleanField(default=True) is_friend = models.BooleanField(default=False) objects = SomeManager() relationships = models.ManyToManyField(User, through=Relationship, symmetrical=False) relationships.contribute_to_class(User, 'relationships') Here i take the User object and use contribute_to_class to add 'relationships' to the User object. The relationship show up, but if call User.relationships.friends it should run the friends() method, but its failing. Any ideas how i would do this? Thanks

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  • Abstract classes in shared library

    - by JTom
    Hi, I have an ordinary abstract class that has couple of pure virtual methods. The class itself is a part of the shared library. The compilation of the shared library itself is OK. But when the library is linked to another program that has another class deriving from the abstract one in the shared library and defining the pure virtual methods, I get the following linker error: I compile like this..: g++ -I../path/to/the/library main.cpp derived.cpp -L../path/to/the/library -lsomename -o shared ...and the linker error is: libsomename.so: undefined reference to `AbstractClass::method()' It's like the abstract class cannot access its pure virtual methods but I do not try to make any instance of the abstract class anywhere in the library. What could be the problem?

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  • Rails with DB2 and multiple schemas

    - by GNUMatrix
    I have a 'legacy' DB2 database that has many other applications and users. Trying to experiment with a rails app. Got everything working great with the ibm_db driver. Problem is that I have some tables like schema1.products, schema1.sales and other tables like schema2.employees and schema2.payroll. In the ibm_db adapter connection, I specify a schema, like schema1 or schema2, and I can work within that one schema, but I need to be able to easily (and transparently) reference both schemas basically interchangeably. I don't want to break the other apps, and the SQL I would normally write against DB2 doesn't have any of these restrictions (schemas can be mixed in SQL against DB2 without any trouble at all). I would like to just specify table names as "schema1.products" for example and be done with it, but that doesn't seem to jive with the "rails way" of going about it. Suggestions?

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  • Executing a dynamically bound function in Clojure

    - by Carl Smotricz
    I'd like to pre-store a bunch of function calls in a data structure and later evaluate/execute them from within another function. This works as planned for functions defined at namespace level with defn (even though the function definition comes after my creation of the data structure) but will not work with functions defined by let [name (fn or letfn inside the function. Here's my small self-contained example: (def todoA '(funcA)) (def todoB '(funcB)) (def todoC '(funcC)) (def todoD '(funcD)) ; unused (defn funcA [] (println "hello funcA!")) (declare funcB funcC) (defn runit [] (let [funcB (fn [] (println "hello funcB"))] (letfn [(funcC [] (println "hello funcC!"))] (funcA) (eval todoA) ; OK (funcB) ; OK (eval todoB) ; "Unable to resolve symbol: funcB in this context" at line 2 (funcC) ; OK (eval todoC) ; "Unable to resolve symbol: funcC in this context" at line 3 ))) Is there a simple fix I could undertake to get eval'd quoted calls to functions to work for functions defined inside another function?

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  • problem with opening link through safari with webview

    - by Desmond
    hi i had encounter a problem opening a web link through safari. this is my code header #import <UIKit/UIKit.h> @interface qrcode_info : UIViewController <UIWebViewDelegate,UIAlertViewDelegate> { } @property (nonatomic, retain) IBOutlet UIWebView *Web; @end //main file #import "qrcode_info.h" @implementation qrcode_info @synthesize Web; -(BOOL)Web:(UIWebView *)Web shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType { if (navigationType == UIWebViewNavigationTypeLinkClicked) { [[UIApplication sharedApplication] openURL:[request URL]]; return NO; } return YES; } //[[UIApplication sharedApplication] openURL:[inRequest URL]]; //return NO; - (void)viewDidLoad { [super viewDidLoad]; [Web loadRequest:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"help" ofType:@"html"] isDirectory:NO]]]; //self.wvTutorial = [[WebViewController alloc] initWithNibName:@”WebView” bundle:[NSBundle mainBundle]]; }

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  • Adding image to navigation bar

    - by 4thSpace
    I'd like an image to take up all of a navigation bar. This is the navigation that comes with a navigation based app. It appears on the RootViewController with the accompanying UITableView. I've seen some examples of how this might work. Set navigation bar title: UIImage *image = [UIImage imageNamed:@"TableviewCellLightBlue.png"]; UIImageView *imageView = [[UIImageView alloc] initWithImage:image]; [self.navigationController.navigationBar.topItem setTitleView:imageView]; The problem there is it only covers the title rather than the entire navigation bar. There is also this thread: http://discussions.apple.com/message.jspa?messageID=9254241#9254241. Towards the end, the solution looks to use a tab bar, which I'm not using. It is that complicated to set a navigation bar background? Is there some other simpler technique? I'd like to have a background for the navigation and still be able to use title text.

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  • Getting publish_stream extended permission from the user

    - by José Joel.
    I was ussing Facbook connect in my iPhone app, but in december the posts stopped working. After some research I found that i'm supossed to use stream.publish, something like: NSString *att = @"{\"bob\":\"i\'m happy\",\"caption\": \"User rated the internet 5 stars\", \"description\": \"a giant cat\"}"; NSDictionary *attachment = [NSDictionary dictionaryWithObject:att forKey:@"attachment"]; [[FBRequest requestWithDelegate:self] call:@"facebook.stream.publish" params:attachment]; Which i think it's correct, but the posts still don't work. Someone told me that i need to get publish_stream extended permission from the user, but i dont know how to do that.

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