Search Results

Search found 50994 results on 2040 pages for 'simple solution'.

Page 419/2040 | < Previous Page | 415 416 417 418 419 420 421 422 423 424 425 426  | Next Page >

  • What is the safest way to pass strings around in C?

    - by chucknelson
    I have a program in C using Solaris with VERY ancient compatibility it seems. Many examples, even here on SO, don't work, as well as lots of code I've written on Mac OS X. So when using very strict C, what is the safest way to pass strings? I'm currently using char pointers all over the place, due to what I thought was simplicity. So I have functions that return char*, I'm passing char* to them, etc. I'm already seeing strange behavior, like a char* I passed having its value right when I enter a function, and then the value being mysteriously gone OR corrupted/overwritten after something simple like one printf() or an malloc to some other pointer. I was thinking maybe declaring a local char[] inside each function, using strcpy() immediately, and then eventually returning a pointer where char *returnval = strdup(localchar[]); This seems...sloppy. Can anyone point me in the right direction on a simple requirement?

    Read the article

  • Recommended Python publish/subscribe/dispatch module ?

    - by Eli Bendersky
    From PyPubSub: Pypubsub provides a simple way for your Python application to decouple its components: parts of your application can publish messages (with or without data) and other parts can subscribe/receive them. This allows message "senders" and message "listeners" to be unaware of each other: one doesn't need to import the other a sender doesn't need to know "who" gets the messages, what the listeners will do with the data, or even if any listener will get the message data. similarly, listeners don't need to worry about where messages come from. This is a great tool for implementing a Model-View-Controller architecture or any similar architecture that promotes decoupling of its components. There seem to be quite a few Python modules for publishing/subscribing floating around the web, from PyPubSub, to PyDispatcher to simple "home-cooked" classes. Can you recommend a module that works well in most cases ? Which modules have you had positive experience with ? Negative ? Thanks in advance

    Read the article

  • Interactive World Map, highlight countries on mouseover

    - by BrenGG
    I need to create an interactive world map on the front page of a site, the view portal will be about 650x200 pixels. The interactivity would include the following, mouse-over a country would highlight (the countries are will literally be filled with "red" for example) that country and display the countries' name (preferably text in a div), I will also be linking the highlighting event with a that will highlight a country when selected. I am having a difficult time finding a suitable solution, I refuse to use or learn a proprietry technology such as flash so it is not an option. I created a simple mockup using openlayers and a custom map image but the countries' markers load too slowly in IE6. Also svg seems too large, as I tried to use RaphaelJS, but abondoned it when I realised the world map data is 1.2mb which is totally un acceptable for the front page of a site.. I am really at a loss on how I am going to do this, my last resort is to manually create 250+ (however many countries there are) pngs and apply mouseover events to hotspots in the image... but this is probably going to be a dead end too.. desperately seeking a solution, any helpful comments will be appreciated!

    Read the article

  • Counting string length in javascript and Ruby on Rails

    - by williamjones
    I've got a text area on a web site that should be limited in length. I'm allowing users to enter 255 characters, and am enforcing that limit with a Rails validation: validates_length_of :body, :maximum => 255 At the same time, I added a javascript char counter like you see on Twitter, to give feedback to the user on how many characters he has already used, and to disable the submit button when over length, and am getting that length in Javascript with a call like this: element.length Lastly, to enforce data integrity, in my Postgres database, I have created this field as a varchar(255) as a last line of defense. Unfortunately, these methods of counting characters do not appear to be directly compatible. Javascript counts the best, in that it counts what users consider as number of characters where everything is a single character. Once the submission hits Rails, however, all of the carriage returns have been converted to \r\n, now taking up 2 characters worth of space, which makes a close call fail Rails validations. Even if I were to handcode a different length validation in Rails, it would still fail when it hits the database I think, though I haven't confirmed this yet. What's the best way for me to make all this work the way the user would want? Best Solution: an approach that would enable me to meet user expectations, where each character of any type is only one character. If this means increasing the length of the varchar database field, a user should not be able to sneakily send a hand-crafted post that creates a row with more than 255 letters. Somewhat Acceptable Solution: a javascript change that enables the user to see the real character count, such that hitting return increments the counter 2 characters at a time, while properly handling all symbols that might have these strange behaviors.

    Read the article

  • Store the cache data locally

    - by Lu Lu
    Hello, I develops a C# Winform application, it is a client and connect to web service to get data. The data returned by webservice is a DataTable. Client will display it on a DataGridView. My problem is that: Client will take more time to get all data from server (web service is not local with client). So I must to use a thread to get data. This is my model: Client create a thread to get data - thread complete and send event to client - client display data on datagridview on a form. However, when user closes the form, user can open this form in another time, and client must get data again. This solution will cause the client slowly. So, I think about a cached data: Client <---get/add/edit/delete--- Cached Data ---get/add/edit/delete---Server (web service) Please give me some suggestions. Example: cached data should be developed in another application which is same host with client? Or cached data is running in client. Please give me some techniques to implement this solution. If having any examples, please give me. Thanks.

    Read the article

  • Dynamic stack allocation in C++

    - by Poni
    I want to allocate memory on the stack. Heard of _alloca / alloca and I understand that these are compiler-specific stuff, which I don't like. So, I came-up with my own solution (which might have it's own flaws) and I want you to review/improve it so for once and for all we'll have this code working: /*#define allocate_on_stack(pointer, size) \ __asm \ { \ mov [pointer], esp; \ sub esp, [size]; \ }*/ /*#define deallocate_from_stack(size) \ __asm \ { \ add esp, [size]; \ }*/ void test() { int buff_size = 4 * 2; char *buff = 0; __asm { // allocate mov [buff], esp; sub esp, [buff_size]; } // playing with the stack-allocated memory for(int i = 0; i < buff_size; i++) buff[i] = 0x11; __asm { // deallocate add esp, [buff_size]; } } void main() { __asm int 3h; test(); } Compiled with VC9. What flaws do you see in it? Me for example, not sure that subtracting from ESP is the solution for "any kind of CPU". Also, I'd like to make the commented-out macros work but for some reason I can't.

    Read the article

  • About data size filled in the buffer

    - by Bohan Lu
    I need low-latency audio in my project, and I know Android 2.3 supports OpenSL ES. I have read documents and sample code and I decide to use Android simple buffer queue to do the play and record. I now try to write a simple application to do the test. However, I have some questions about recording. If I set the recorder stop when it is recording, how do I know the exact number of bytes filled in the last buffer if it is not filled up ? In 1.1 version, the callback function has some parameters about buffer and its filled data, but there is no such parameters in version 1.0.1. Is there any way to get this information ? Any suggestion would be greatly appreciated !

    Read the article

  • Dynamic access of classes of a given namespace

    - by user322383
    Hi! I'm writing an interface that will be implemented by a lot of classes, and I'm writing a class that will hold a collection of instances of these implementations. Every class will have a default constructor. So, is there a simple way (e.g. using some kind of reflection) to put an instance of each of these implementing classes to the collection? Besides doing it manually, which is simple, yes, but a lot of work and error prone (what if I missed an implementation while writing the method? What if a new implementation came and I forgot to update the given method?). So, what I would like is to be able to iterate through all classes of a given namespace or maybe through the list of all available classes. My method then would simply check, through reflection, if the given class implements the given interface, and if it does, puts it into the collection. Thank you.

    Read the article

  • Memorystream and Large Object Heap

    - by Flo
    I have to transfer large files between computers on via unreliable connections using WCF. Because I want to be able to resume the file and I don't want to be limited in my filesize by WCF, I am chunking the files into 1MB pieces. These "chunk" are transported as stream. Which works quite nice, so far. My steps are: open filestream read chunk from file into byet[] and create memorystream transfer chunk back to 2. until the whole file is sent My problem is in step 2. I assume that when I create a memory stream from a byte array, it will end up on the LOH and ultimately cause an outofmemory exception. I could not actually create this error, maybe I am wrong in my assumption. Now, I don't want to send the byte[] in the message, as WCF will tell me the array size is too big. I can change the max allowed array size and/or the size of my chunk, but I hope there is another solution. My actual question(s): Will my current solution create objects on the LOH and will that cause me problem? Is there a better way to solve this? Btw.: On the receiving side I simple read smaller chunks from the arriving stream and write them directly into the file, so no large byte arrays involved.

    Read the article

  • Typecasting a floating value or using the math.h floor* functions?

    - by nobody
    Hi, I am coding up an implementation of Interpolation Search in C. The question is actually rather simple, I need to use the floating operations to do linear interpolation to find the correct index which will eventually be an integer result. In particular my probe index is: t = i + floor((((k-low)/(high-low)) * (j-i))); where, i,j,k,t are unsigned ints, and high,low are doubles. Would this be equivalent to: t = i + (unsigned int)(((k-low)/(high-low)) * (j-i)); Is there any reason I would actually want to use math.h floor* functions over just a simple (int) typecast?

    Read the article

  • Ternary operator

    - by Antoine Leclair
    In PHP, I often use the ternary operator to add an attribute to an html element if it applies to the element in question. For example: <select name="blah"> <option value="1"<?= $blah == 1 ? ' selected="selected"' : '' ?>> One </option> <option value="2"<?= $blah == 2 ? ' selected="selected"' : '' ?>> Two </option> </select> I'm starting a project with Pylons using Mako for the templating. How can I achieve something similar? Right now, I see two possibilities that are not ideal. Solution 1: <select name="blah"> % if blah == 1: <option value="1" selected="selected">One</option> % else: <option value="1">One</option> % endif % if blah == 2: <option value="2" selected="selected">Two</option> % else: <option value="2">Two</option> % endif </select> Solution 2: <select name="blah"> <option value="1" % if blah == 1: selected="selected" % endif >One</option> <option value="2" % if blah == 2: selected="selected" % endif >Two</option> </select> In this particular case, the value is equal to the variable tested (value="1" = blah == 1), but I use the same pattern in other situations, like <?= isset($variable) ? ' value="$variable" : '' ?>. I am looking for a clean way to achieve this using Mako.

    Read the article

  • How to display configurable product in each color in product listing?

    - by Thomas
    I have a configurable product which is available in many different colors and sizes. I want the configurable product to appear once for every color. My idea is to assign one simple product of the configurable product in every color to the category of the configurable product. Then I want to change the listing, so that the (colored) simple product links to it's master product (the configurable one). The other way would be, to just assign the configurable product to a category and then list it multiple times with different colors. But I think this would be to complicated.

    Read the article

  • How does C#'s DateTime.Now affect query plan caching in SQL Server?

    - by Bill Paetzke
    Given: Let's say we have a stored procedure. It reports data back to a user on a webpage. The user can set a date range. If the user sets today's date as the "end date," which includes today's data, the web app passes DateTime.Now to the sql proc. Let's say that one user runs a report--5/1/2010 to now--over and over several times. On the webpage, the user sees "5/1/2010" to "5/4/2010." But the web app passes DateTime.Now to the sql proc as the end date. So, the end date in the proc will always be different, although the user is querying a similar date range. Assume the number of records in the table and number of users are large. So any performance gains matter. Hence the importance of the question. Question: Does passing DateTime.Now as a parameter to a proc prevent SQL Server from caching the query plan? If so, then is the web app missing out on huge performance gains? Possible Solution: I thought DateTime.Today.AddDays(1) would be a possible solution. It would allow the user to get the latest data and always pass the same end date to the sql proc--"5/5/2010" in this case. Please speak to this as well. Sample proc and execution (if that helps to understand): CREATE PROCEDURE GetFooData @StartDate datetime @EndDate datetime AS SELECT * FROM Foo WHERE LogDate >= @StartDate AND LogDate < @EndDate Here's a sample execution using DateTime.Now: EXEC GetFooData '2010-05-01', '2010-05-04 15:41:27' -- passed in DateTime.Now Here's a sample execution using DateTime.Today.AddDays(1) EXEC GetFooData '2010-05-01', '2010-05-05' -- passed in DateTime.Today.AddDays(1) The same data is returned for both procs, since the current time is: 2010-05-04 15:41:27.

    Read the article

  • toplink prefixes table with TL_ while update operation

    - by Dewfy
    I have very simple named query on JPA (toplink ): UPDATE Server s SET s.isECM = 0 I don't carry about cache or validity of already preloaded entities. But database connection is performed from restricted account (only INSERT/UPDATE/DELETE). It is appeared that toplink on this query executes (and failed since TL_Server is not exists) very strange SQL: INSERT INTO TL_Server (elementId, IsECM) SELECT t0.ElementId, ? FROM Element t0, Server t1 WHERE ((t1.elementId = t0.ElementId) AND (t0.elementType = ?)) bind => [0, Server] What is this? How the simple UPDATE appears an INSERT? Why toplink queries TL_?

    Read the article

  • The "correct" way to define an exception in Python without PyLint complaining

    - by Evgeny
    I'm trying to define my own (very simple) exception class in Python 2.6, but no matter how I do it I get some warning. First, the simplest way: class MyException(Exception): pass This works, but prints out a warning at runtime: DeprecationWarning: BaseException.message has been deprecated as of Python 2.6 OK, so that's not the way. I then tried: class MyException(Exception): def __init__(self, message): self.message = message This also works, but PyLint reports a warning: W0231: MyException.__init__: __init__ method from base class 'Exception' is not called. So I tried calling it: class MyException(Exception): def __init__(self, message): super(Exception, self).__init__(message) self.message = message This works, too! But now PyLint reports an error: E1003: MyException.__init__: Bad first argument 'Exception' given to super class How the hell do I do such a simple thing without any warnings?

    Read the article

  • Remove Duplicates from JavaScript Array

    - by kramden88
    This seems like such a simple need but I've spent an inordinate amount of time trying to do this to no avail. I've looked at other questions on SO and I haven't found what I need. I have a very simple JavaScript array such as peoplenames = new Array("Mike","Matt","Nancy","Adam","Jenny","Nancy","Carl"); that may or may not contain duplicates and I need to simply remove the duplicates and put the unique values in a new array. That's it. I could point to all the codes that I've tried but I think it's useless because they don't work. If anyone has done this and can help me out I'd really appreciate it. JavaScript or jQuery solutions are both acceptable.

    Read the article

  • BeautifulSoup HTMLParseError. What's wrong with this?

    - by user1915496
    This is my code: from bs4 import BeautifulSoup as BS import urllib2 url = "http://services.runescape.com/m=news/recruit-a-friend-for-free-membership-and-xp" res = urllib2.urlopen(url) soup = BS(res.read()) other_content = soup.find_all('div',{'class':'Content'})[0] print other_content Yet an error comes up: /Library/Python/2.7/site-packages/bs4/builder/_htmlparser.py:149: RuntimeWarning: Python's built-in HTMLParser cannot parse the given document. This is not a bug in Beautiful Soup. The best solution is to install an external parser (lxml or html5lib), and use Beautiful Soup with that parser. See http://www.crummy.com/software/BeautifulSoup/bs4/doc/#installing-a-parser for help. "Python's built-in HTMLParser cannot parse the given document. This is not a bug in Beautiful Soup. The best solution is to install an external parser (lxml or html5lib), and use Beautiful Soup with that parser. See http://www.crummy.com/software/BeautifulSoup/bs4/doc/#installing-a-parser for help.")) Traceback (most recent call last): File "web.py", line 5, in <module> soup = BS(res.read()) File "/Library/Python/2.7/site-packages/bs4/__init__.py", line 172, in __init__ self._feed() File "/Library/Python/2.7/site-packages/bs4/__init__.py", line 185, in _feed self.builder.feed(self.markup) File "/Library/Python/2.7/site-packages/bs4/builder/_htmlparser.py", line 150, in feed raise e I've let two other people use this code, and it works for them perfectly fine. Why is it not working for me? I have bs4 installed...

    Read the article

  • Java2D: Fill a convex rounded polygon (QuadCurves)

    - by Martijn Courteaux
    Hi, If I have a QuadCurve like this (+ = node): + + \ ./ +--?? And I fill it in Java 2D the result is something like this: (x = colored) +xxxxxxxxx+ \xxxxxx./ +--?? But I want to color the other side: + + x\ ./x xxx +--??xx xxxxxxxxxxx This succeeds by drawing a rectangle around the curve in the color I want to color the other side and then fill the curve with the background color. But this isn't good enough to fill a convex rounded (based on QuadCurves) polygon. In case of some coordinates for the rectangles (as explained in the trick I used) overlap other pieces of the polygon. Here are two images (the green area is my polygon): So, the question is simple: "How can I color a shape build of curves?" But to the answer will not be simple I think... Any advice would be VERY VERY appreciated. Thanks in advance. Maybe I'm going to make a bounty for this question if I don't get an answer

    Read the article

  • functions inside or outside jquery document ready

    - by Hans
    Up until now I just put all my jQuery goodness inside the $(document).ready() function, including simple functions used in certain user interactions. But functions that don´t require the DOM document to be loaded or are only called afterwards anyway, can be placed outside the $(document).ready() as well. Consider for example a very simple validation function such as: function hexvalidate(color) { // Validates 3-digit or 6-digit hex color codes var reg = /^(#)?([0-9a-fA-F]{3})([0-9a-fA-F]{3})?$/; return reg.test(color); } The function is only called from within the $(document).ready() function though. What is best practice (syntax, speed); placing such a function inside or outside the jquery document ready function?

    Read the article

  • Integer output in Java method not same as pre-converted char value.

    - by David
    I'm trying to parse a simple text file in an integer method and then output an integer from such file so that other parts of the program can use it. For testing purposes it also displays the character value (9 in this case). The integer value for some reason is 57. I've also tried it with another part of the text file (which in that case should be 5, but is instead 53). After looking at an ASCII chart, I see that 57 is the ASCII version of the "symbol" 9 and that 53 is the ASCII version of the "symbol" 5. Is there any simple way I can fix this? I'm getting kind of frustrated as I'm a Java newbie (I've mostly only used FreePascal before this).

    Read the article

  • MVVM Listbox DataTemplate SelectedItem

    - by StinkerPeter
    I am using a ListBox with a DataTemplate as shown below (xaml simplified and variable names changed). <ListBox ItemsSource="{Binding Path=ObservCollectionItems}" SelectedItem="{Binding Path=SelectedItemVar, Mode=TwoWay}"> <ListBox.ItemTemplate> <DataTemplate> <StackPanel> <TextBlock Text="{Binding SomeVar}" /> <Border> <StackPanel> <Button Content="String1" Command="{Binding DataContext.Command1} RelativeSource={RelativeSource FindAncestor, ListBox, 1}}" /> <Button Content="String2" Command="{Binding DataContext.Command2} RelativeSource={RelativeSource FindAncestor, ListBox, 1}}" /> </StackPanel> </Border> </StackPanel> </DataTemplate> <ListBox.ItemTemplate> </ListBox> I need the SelectedItemVar (dependency property) to update when I click on one of the buttons. SelectedItemVar is then used for the respective button's command. SelectedItemVar does update when I click on the TextBlock or the Border, but not when I click either button. I found a non-MVVM solution to this problem here. I do not want to add code in the file-behind to solve this, as they did in the link. Is there a clean solution that can be done in XAML. Beyond the non-MVVM solutions, I have not found anyone with this problem. I would have thought this was fairly common. Finally, I found this Command="{Binding DataContext.CommandName} RelativeSource={RelativeSource FindAncestor, ListBox, 1} for the Command binding. I do not fully understand what it is doing, but I do know that the command wasn't firing when I was binding directly to CommandName.

    Read the article

  • Tail recursion and memoization with C#

    - by Jay
    I'm writing a function that finds the full path of a directory based on a database table of entries. Each record contains a key, the directory's name, and the key of the parent directory (it's the Directory table in an MSI if you're familiar). I had an iterative solution, but it started looking a little nasty. I thought I could write an elegant tail recursive solution, but I'm not sure anymore. I'll show you my code and then explain the issues I'm facing. Dictionary<string, string> m_directoryKeyToFullPathDictionary = new Dictionary<string, string>(); ... private string ExpandDirectoryKey(Database database, string directoryKey) { // check for terminating condition string fullPath; if (m_directoryKeyToFullPathDictionary.TryGetValue(directoryKey, out fullPath)) { return fullPath; } // inductive step Record record = ExecuteQuery(database, "SELECT DefaultDir, Directory_Parent FROM Directory where Directory.Directory='{0}'", directoryKey); // null check string directoryName = record.GetString("DefaultDir"); string parentDirectoryKey = record.GetString("Directory_Parent"); return Path.Combine(ExpandDirectoryKey(database, parentDirectoryKey), directoryName); } This is how the code looked when I realized I had a problem (with some minor validation/massaging removed). I want to use memoization to short circuit whenever possible, but that requires me to make a function call to the dictionary to store the output of the recursive ExpandDirectoryKey call. I realize that I also have a Path.Combine call there, but I think that can be circumvented with a ... + Path.DirectorySeparatorChar + .... I thought about using a helper method that would memoize the directory and return the value so that I could call it like this at the end of the function above: return MemoizeHelper( m_directoryKeyToFullPathDictionary, Path.Combine(ExpandDirectoryKey(database, parentDirectoryKey)), directoryName); But I feel like that's cheating and not going to be optimized as tail recursion. Any ideas? Should I be using a completely different strategy? This doesn't need to be a super efficient algorithm at all, I'm just really curious. I'm using .NET 4.0, btw. Thanks!

    Read the article

  • LINQ-to-SQL vs stored procedures?

    - by scottmarlowe
    I took a look at the "Beginner's Guide to LINQ" post here on StackOverflow (http://stackoverflow.com/questions/8050/beginners-guide-to-linq), but had a follow-up question: We're about to ramp up a new project where nearly all of our database op's will be fairly simple data retrievals (there's another segment of the project which already writes the data). Most of our other projects up to this point make use of stored procedures for such things. However, I'd like to leverage LINQ-to-SQL if it makes more sense. So, the question is this: For simple data retrievals, which approach is better, LINQ-to-SQL or stored procs? Any specific pro's or con's? Thanks.

    Read the article

< Previous Page | 415 416 417 418 419 420 421 422 423 424 425 426  | Next Page >