Search Results

Search found 13794 results on 552 pages for 'variable scope'.

Page 295/552 | < Previous Page | 291 292 293 294 295 296 297 298 299 300 301 302  | Next Page >

  • Metaprogramming ActiveRecord Rails

    - by Dimitar Vouldjeff
    Hi, I have the following code in my project`s lib directory module Pasta module ClassMethods def self.has_coordinates self.send :include, InstanceMethods end end module InstanceMethods def coordinates [longitude ||= 43.0, latitude ||= 25.0] end end ActiveRecord::Base.extend ClassMethods end And it should create a class method for ActiveRecord::Base - has_coordinates - which I can "assign" to models... But I receive the error undefined local variable or method 'has_coordinates' Thanks in advance!

    Read the article

  • Java replacement for C macros

    - by thkala
    Recently I refactored the code of a 3rd party hash function from C++ to C. The process was relatively painless, with only a few changes of note. Now I want to write the same function in Java and I came upon a slight issue. In the C/C++ code there is a C preprocessor macro that takes a few integer variables names as arguments and performs a bunch of bitwise operations with their contents and a few constants. That macro is used in several different places, therefore its presence avoids a fair bit of code duplication. In Java, however, there is no equivalent for the C preprocessor. There is also no way to affect any basic type passed as an argument to a method - even autoboxing produces immutable objects. Coupled with the fact that Java methods return a single value, I can't seem to find a simple way to rewrite the macro. Avenues that I considered: Expand the macro by hand everywhere: It would work, but the code duplication could make things interesting in the long run. Write a method that returns an array: This would also work, but it would repeatedly result into code like this: long tmp[] = bitops(k, l, m, x, y, z); k = tmp[0]; l = tmp[1]; m = tmp[2]; x = tmp[3]; y = tmp[4]; z = tmp[5]; Write a method that takes an array as an argument: This would mean that all variable names would be reduced to array element references - it would be rather hard to keep track of which index corresponds to which variable. Create a separate class e.g. State with public fields of the appropriate type and use that as an argument to a method: This is my current solution. It allows the method to alter the variables, while still keeping their names. It has the disadvantage, however, that the State class will get more and more complex, as more macros and variables are added, in order to avoid copying values back and forth among different State objects. How would you rewrite such a C macro in Java? Is there a more appropriate way to deal with this, using the facilities provided by the standard Java 6 Development Kit (i.e. without 3rd party libraries or a separate preprocessor)?

    Read the article

  • Can I view a list of public variables of some Adobe Air app or web flash file from another app?

    - by Parris
    I was thinking about creating making AIM pluggin that checks pandora one (desktop) or pandora website periodically to see what is currently playing and update a user's status. I suppose the main question is there a clever way to access a "public" variable from some open Adobe Air process? I KNOW this sounds like some crazy security flaw, but it may also be a feature. I am pretty sure javascript can potentially handle it. Thanks!

    Read the article

  • os.walk in python not running with cmd line parameter passed as path

    - by kartiku
    Hello, I needed to find the number of files in a folder on the system. This is what i used: file_count = sum((len(f) for _, _, f in os.walk('path'))) This works fine when we specify the path as a string in quotes, but when I enter a variable name that holds the path, type(file_count) is a generator object, and hence cannot be used as an integer. How to solve this and why does this happen?

    Read the article

  • How do I use multiple arguments from an array to construct an execl() call in C?

    - by chucknelson
    I have a string array in C named args[] - now how can I use this list of arguments to construct a proper call to execl()? So if the array contains: {"/bin/ls","ls","-a","-l"} ...how can I eventually construct an execl() call that is: execl("/bin/ls","ls","-a","-l",NULL); I must be thinking about this wrong, as I can't find anything online, just talk about defining functions that can take a variable number of arguments.

    Read the article

  • Why is C# statically typed?

    - by terrani
    I am a PHP web programmer who is trying to learn C#. I would like to know why C# requires me to specify the data type when creating a variable. Class classInstance = new Class(); Why do we need to know the data type before a class instance?

    Read the article

  • How to fetch parameters when using the Apache Commons CLI library

    - by Mridang Agarwalla
    I'm using the Apache Commons CLI to handle command line arguments in Java. I've figured out my way around it to a decent extent but I need a little help. I've declared the a and b options and I'm able to access the value using CommandLine.getOptionValue. Usage: myapp [OPTION] [DIRECTORY] Options: -a Option A -b Option B How do I declare and access the DIRECTORY variable? Thank you.

    Read the article

  • filesize of large files in c

    - by endeavormac
    How can I get the filesize of a file in C when the filesize is greater than 4gb? ftell returns a 4 byte signed long, limiting it to two bytes. stat has a variable of type off_t which is also 4 bytes (not sure of sign), so at most it can tell me the size of a 4gb file. What if the file is larger than 4 gb?

    Read the article

  • What if I made an explicit reference to 'this' for use inside an inner class?

    - by badp
    So far, I've used this approach to access this from the scope of an inner class: class FooManagementWindow extends JFrame { JButton rejectFoo; //... void getFooAcceptingPanel(){ //... final FooManagementWindow referenceToThis = this; rejectFoo = new JButton("Reject"); rejectFoo.addEventListener(new EventListener() { @Override public void actionPerformed(ActionEvent arg) { referenceToThis.setEnabled(false); //this requires a network call //... referenceToThis.setEnabled(true); //the user may resume his work } }); //... } } However, I just learned that instead of declaring referenceToThis, a direct reference is kept for me as: FooManagementWindow.this I have no reason to think my less standard approach may lead to errors or weird corner cases. Or are there?

    Read the article

  • javascript singleton question

    - by Shawn
    I just read a few threads on the discussion of singleton design in javascript. I'm 100% new to the Design Pattern stuff but as I see since a Singleton by definition won't have the need to be instantiated, conceptually if it's not to be instantiated, in my opinion it doesn't have to be treated like conventional objects which are created from a blueprint(classes). So my wonder is why not just think of a singleton just as something statically available that is wrapped in some sort of scope and that should be all. From the threads I saw, most of them make a singleton though traditional javascript new function(){} followed by making a pseudo constructor. Well I just think an object literal is enough enough: var singleton = { dothis: function(){}, dothat: function(){} } right? Or anybody got better insights? [update] : Again my point is why don't people just use a simpler way to make singletons in javascript as I showed in the second snippet, if there's an absolute reason please tell me. I'm usually afraid of this kind of situation that I simplify things to much :D

    Read the article

  • Saving a jpeg with PHP sent from flash

    - by kielie
    Hi guys, I am trying to take a variable sent from flash, and save it to a spot on my web server using PHP, I have NO idea how to do this, and I can't seem to find code that works anywhere on the web, any help would be greatly appreciated, thanx!

    Read the article

  • What .NET serializers have fixed size output for a given class?

    - by Jader Dias
    XML based serializers have variable size output for a given class. I can't use them to append data to my Memcached list, since I won't be able to retrieve that information later. But if I knew my serializer produced a fixed size output (N bytes), I could retrieve my data by splitting my list in N bytes chunks and then deserializing those chunks individually. I have created my own serializer for my class, but what other serializers I could use?

    Read the article

  • Big-O complexity of c^n + n*(logn)^2 + (10*n)^c

    - by zebraman
    I need to derive the Big-O complexity of this expression: c^n + n*(log(n))^2 + (10*n)^c where c is a constant and n is a variable. I'm pretty sure I understand how to derive the Big-O complexity of each term individually, I just don't know how the Big-O complexity changes when the terms are combined like this. Ideas? Any help would be great, thanks.

    Read the article

  • How to implement a Mutex in Python when using Gtk with PyGTK

    - by Julian
    Hi, I have an application that starts several threads using gobject.timeout_add(delay, function) Now in my function I want to test and set on some variable, e.g. def function(self): if flag == True: flag = False doSomething() Now to make this threadsafe, I would have to lock the function using some mutex lock. Is this possible with Gtk? Or can I use the Python Lock objects from threading?

    Read the article

  • Zsh command substitution

    - by Dr. Watson
    I usually work with BASH, but I'm trying to setup a cronjob from a machine and user account that is configured with zsh. When the cronjob runs, the date variable does not contain the date, just the string for the command to return the date. DATE=$(date +%Y%m%d) 55 15 * * 1-5 scp user@host:/path/to/some/file/$DATE.log /tmp I've tried using backticks rather than $() around the command, but that did not work either. Is there a special way to do command substitution in zsh?

    Read the article

  • Eval IronPython Scripts during ASP.NET Web Request; Static Engine or Not

    - by Josh Pearce
    I would like to create an ASP.NET MVC web application which has extensible logic that does not require a re-build. I was thinking of creating a filter which had an instance of the IronPython engine. What I would like to know is: how much overhead is there in creating a new engine during each web request, and would it be a better idea to keep a static engine around? However, if I were to keep a single static engine around, what are the issues I might run into as far as locking and script scope? Is it possible to have multiple scopes in the same IropPython engine so I don't get variable collision and security issues between web requests?

    Read the article

  • Visual C++: Invalid allocation size. How to force the debugger to stop on this message?

    - by James Roth
    The MFC program I am debugging is printing this message in the "Output" window in Visual Studio 9.0: HEAP[AppName.exe]: Invalid allocation size - 99999998 (exceeded 7ffdefff) I'm pretty sure this is due to a bad "new", uninitialized variable or similar error. The question is: how do I get the debugger to stop on this message so that I can view the stack trace and solve the problem?

    Read the article

  • Hibernate: getting a record but it's being updated in the database?

    - by jack
    For some reason Hibernate seems to be keeping my session open and updating the object without me explicitely invoking a save/update/saveorupdate. I guess the session is staying open and it's beeing marked as dirty. However this is not the desired behaviour, so what's the cleanest way to fix this? The issue seems to occur because I store a phone number without formatting in the database but the getter of the object returns a formatted telephone number. My flow: go to a jsp = controller = service = dao DAO getter function if(userId != 0) { return (User)dbFactory.get(User.class, userId); } return null; The service just passes it to the controller and the controller puts te User object in the request scope. I display it on my JSP page using EL.

    Read the article

  • question related to backbutton of UIToolbar

    - by user217572
    sir I'm getting 2 different values in back button click My question is, *If I want to back to view as per my value coming in int variable. how is it possible? *My second question is that my project is based on UINavigationController So,how should i do that? bcoz i'm using PushviewController to puch the new view from olderview Thanks in advance

    Read the article

  • Function returning MYSQL_ROW

    - by Gabe
    I'm working on a system using lots of MySQL queries and I'm running into some memory problems I'm pretty sure have to do with me not handling pointers right... Basically, I've got something like this: MYSQL_ROW function1() { string query="SELECT * FROM table limit 1;"; MYSQL_ROW return_row; mysql_init(&connection); // "connection" is a global variable if (mysql_real_connect(&connection,HOST,USER,PASS,DB,0,NULL,0)){ if (mysql_query(&connection,query.c_str())) cout << "Error: " << mysql_error(&connection); else{ resp = mysql_store_result(&connection); //"resp" is also global if (resp) return_row = mysql_fetch_row(resp); mysql_free_result(resp); } mysql_close(&connection); }else{ cout << "connection failed\n"; if (mysql_errno(&connection)) cout << "Error: " << mysql_errno(&connection) << " " << mysql_error(&connection); } return return_row; } And function2(): MYSQL_ROW function2(MYSQL_ROW row) { string query = "select * from table2 where code = '" + string(row[2]) + "'"; MYSQL_ROW retorno; mysql_init(&connection); if (mysql_real_connect(&connection,HOST,USER,PASS,DB,0,NULL,0)){ if (mysql_query(&connection,query.c_str())) cout << "Error: " << mysql_error(&conexao); else{ // My "debugging" shows me at this point `row[2]` is already fubar resp = mysql_store_result(&connection); if (resp) return_row = mysql_fetch_row(resp); mysql_free_result(resp); } mysql_close(&connection); }else{ cout << "connection failed\n"; if (mysql_errno(&connection)) cout << "Error : " << mysql_errno(&connection) << " " << mysql_error(&connection); } return return_row; } And main() is an infinite loop basically like this: int main( int argc, char* args[] ){ MYSQL_ROW row = NULL; while (1) { row = function1(); if(row != NULL) function2(row); } } (variable and function names have been generalized to protect the innocent) But after the 3rd or 4th call to function2, that only uses row for reading, row starts losing its value coming to a segfault error... Anyone's got any ideas why? I'm not sure the amount of global variables in this code is any good, but I didn't design it and only got until tomorrow to fix and finish it, so workarounds are welcome! Thanks!

    Read the article

< Previous Page | 291 292 293 294 295 296 297 298 299 300 301 302  | Next Page >